PENGEMBANGAN MODEL PEMBINAAN KOMPETENSI CALON GURU MATEMATIKA MELALUI LESSON STUDY

Directory of Open Access Journals (Sweden)

Rahmad Bustanul Anwar

2014-06-01

Full Text Available Education has a very important role in improving the quality of human resources. Therefore, education is expected to be one of the ways to prepare generations of qualified human resources and has the ability to deal with the progress of time and technology development . In order to enhance the quality of student mastery of competencies in the development of prospective teachers in this study will be applied to the activities in the process of lesson study in lecture . Lesson study is a model of coaching to people who work as both teacher educators and lecturers through collaborative learning and assessment in building sustainable learning communities. The purpose of this research is to improve the competence of prospective mathematics teachers through lesson study . More specifically , this study aims to describe the efforts made to improve the pedagogical, professional competence , social competence and personal competence prospective mathematics teachers through lesson study . Subjects in this study were students who took the micro teaching courses totaling 15 students , divided into 3 group . This type of research is a qualitative descriptive study is to develop the competence of prospective mathematics teachers through lesson study . Lesson study conducted collaborated with Action Research activities ( Action Reseach. The results of this research activity is the implementation of lesson study to greater competence to prospective teachers teaching mathematics through the micro subjects namely: pedagogical competence categories were 80 % and 20 % lower, professional competence categories were 46.7 % and 53.3 % lower, personal competence 100 % category being and social competence categories were 86.7 % and 13.3 % lower .

Validation of HEDR models

International Nuclear Information System (INIS)

Napier, B.A.; Simpson, J.C.; Eslinger, P.W.; Ramsdell, J.V. Jr.; Thiede, M.E.; Walters, W.H.

1994-05-01

The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computer models for estimating the possible radiation doses that individuals may have received from past Hanford Site operations. This document describes the validation of these models. In the HEDR Project, the model validation exercise consisted of comparing computational model estimates with limited historical field measurements and experimental measurements that are independent of those used to develop the models. The results of any one test do not mean that a model is valid. Rather, the collection of tests together provide a level of confidence that the HEDR models are valid

Development of Lesson Plans and Student Worksheets Based Socio-Scientific Issues on Pollution Environmental Topic

Science.gov (United States)

Rahayu, S.; Meyliana, M.; Arlingga, A.; Reny, R.; Siahaan, P.; Hernani, H.

2017-09-01

The aim of this study is to develop lesson plans and student worksheets based socio-scientific issues on pollution environmental topic for seventh-grade junior high school students. Environmental pollution topic split into several subtopics namely air pollution, water pollution and soil pollution. The composing of lesson plans were developed based on socio-scientific issues with five stages, namely (1) Motivate; (2) Challenge; (3) Collect scientific evidence; (4) Analyse the evidence; (5) Build knowledge and make connections; and (6) Use evidence. While student worksheets contain articles on socio-scientific issues, practice, and there are a few questions to determine students’ reasoning. The method that is used in this research is research and development (R & D method). Development model used in this study is a model of Plomp that consists of four stages, namely: (1) Initial Research; (2) Design; (3) Realization or Construction; (4) Testing, evaluation and revision; (5) Implementation, while the research was limited to the fourth stage. Lesson plans and student worksheets based on socio-scientific issues was validated through an expert validation. The result showed that lesson plans and student worksheets based socio-scientific issues on pollution theme have a very decent and be able to apply in science classroom.

E-Learning and the iNtegrating Technology for InQuiry (NTeQ) Model Lesson Design

Science.gov (United States)

Flake, Lee Hatch

2017-01-01

The author reflects on the history of technology in education and e-learning and introduces the iNtegrating Technology for inQuiry (NTeQ) model of lesson design authored by Morrison and Lowther (2005). The NTeQ model lesson design is a new pedagogy for academic instruction in response to the growth of the Internet and technological advancements in…

International Space Station Passive Thermal Control System Analysis, Top Ten Lessons-Learned

Science.gov (United States)

Iovine, John

2011-01-01

The International Space Station (ISS) has been on-orbit for over 10 years, and there have been numerous technical challenges along the way from design to assembly to on-orbit anomalies and repairs. The Passive Thermal Control System (PTCS) management team has been a key player in successfully dealing with these challenges. The PTCS team performs thermal analysis in support of design and verification, launch and assembly constraints, integration, sustaining engineering, failure response, and model validation. This analysis is a significant body of work and provides a unique opportunity to compile a wealth of real world engineering and analysis knowledge and the corresponding lessons-learned. The analysis lessons encompass the full life cycle of flight hardware from design to on-orbit performance and sustaining engineering. These lessons can provide significant insight for new projects and programs. Key areas to be presented include thermal model fidelity, verification methods, analysis uncertainty, and operations support.

The effect of application of contextual teaching and learning (CTL model-based on lesson study with mind mapping media to assess student learning outcomes on chemistry on colloid systems

Directory of Open Access Journals (Sweden)

Annisa Fadillah

2017-08-01

Full Text Available The research was conducted to determine the effect of the application of CTL learning model based on lesson study with mind mapping media to the learning outcomes of students on colloid systems. The population of this research was all students of grade XI of SMA N 1 Sunggal. The sample was taken using on the purposive random sampling. The Experiment class was taught with Contextual Teaching and Learning (CTL model based on Lesson Study with Mind Mapping media and the control class taught with conventional learning model. The data was collected using an objective test was consisting of 20 questions which validity, reliability, level of difficulty and power of difference had been tested. T test results showed that tcalculate = 2.1 and ttable = 1.6697 thus tcalculate> ttable which means that Ha is accepted and Ho is rejected. The enhancement of the student learning outcomes showed that the results of experiment class are g = 72.88%, while the control class is 68.97%. From the percentage, it can be seen that learning outcomes of the experiment class are greater than the control class. The analysis of developing cognitive aspects pointed out that C1 = 70.02%, C2 = 73.58%, C3 = 68.63%, Thus the domain of cognitive level are on the cognitive aspects of C2. The result of Lesson Study Analysis showed the results of 71.09% at the first lesson and 88.28% at the second lesson. It means that there is increasing adherence to the indicators after two lessons. Based on the above results, it can be concluded that the result of studying chemistry of the students of class XI of SMA Negeri I Sunggal TA 2014/2015 taught by a CTL model based  on Lesson Study with Mind Mapping media was higher (72.88% than those taught by conventional learning models (68.97% in the subject matter of colloids System.

DMPD: Infectious non-self recognition in invertebrates: lessons from Drosophila andother insect models. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 15476918 Infectious non-self recognition in invertebrates: lessons from Drosophila ...fectious non-self recognition in invertebrates: lessons from Drosophila andother insect models. PubmedID 154...76918 Title Infectious non-self recognition in invertebrates: lessons from Drosop

The effectiveness of Concept Mapping Content Representation Lesson Study (ComCoReLS) model to improve skills of Creating Physics Lesson Plan (CPLP) for pre-service physics teacher

Science.gov (United States)

Purwaningsih, E.; Suyatno; Wasis; Prahani, B. K.

2018-03-01

This research is aimed to analyse the effectiveness of ComCoReLS (Concept Mapping Content Representation Lesson Study) model towards the improvement skills of Creating Physics Lesson Plan (CPLP) for pre-service physics teacher. This research used one group pre-test and post-test design on 12 pre-service physics teacher at University of Malang State (Indonesia) in academic year 2016/2017. Data collection was conducted through test and interview. Skills of creating physics lesson plan for pre-service physics teacher measurement were conducted through Physics Lesson Plan Evaluation Sheet (PLPES). The data analysis technique was done by using paired t-test and n-gain. The CoMCoReLS model consists of 5 phases, including (1) Preparation, (2) Coaching, (3) Guided Practice, (4) Independent Practice, and (5) Evaluation. In the first, second, third and fifth phases are done at University of Malang State, while the fourth phase (Independent Practice) is done in SMAN 1 Singosari, SMAN 2 Malang, SMA Lab UM, MAN 3 Malang. The results showed that there was a significant increase in skills of creating physics lesson plan for pre-service physics teacher at α = 5% and n-gain average of high category. Thus, the ComCoReLS model is effective for improving skills of creating physics lesson plan for pre-service physics teacher.

Digital control for nuclear reactors - lessons learned

International Nuclear Information System (INIS)

Bernard, J.A.; Aviles, B.N.; Lanning, D.D.

1992-01-01

Lessons learned during the course of the now decade-old MIT program on the digital control of nuclear reactors are enumerated. Relative to controller structure, these include the importance of a separate safety system, the need for signal validation, the role of supervisory algorithms, the significance of command validation, and the relevance of automated reasoning. Relative to controller implementation, these include the value of nodal methods to the creation of real-time reactor physics and thermal hydraulic models, the advantages to be gained from the use of real-time system models, and the importance of a multi-tiered structure to the simultaneous achievement of supervisory, global, and local control. Block diagrams are presented of proposed controllers and selected experimental and simulation-study results are shown. In addition, a history is given of the MIT program on reactor digital control

Development and experimental validation of a thermoelectric test bench for laboratory lessons

Directory of Open Access Journals (Sweden)

Antonio Rodríguez

2013-12-01

Full Text Available The refrigeration process reduces the temperature of a space or a given volume while the power generation process employs a source of thermal energy to generate electrical power. Because of the importance of these two processes, training of engineers in this area is of great interest. In engineering courses it is normally studied the vapor compression and absorption refrigeration, and power generation systems such as gas turbine and steam turbine. Another type of cooling and generation less studied within the engineering curriculum, having a great interest, it is cooling and thermal generation based on Peltier and Seebeck effects. The theoretical concepts are useful, but students have difficulties understanding the physical meaning of their possible applications. Providing students with tools to test and apply the theory in real applications, will lead to a better understanding of the subject. Engineers must have strong theoretical, computational and also experimental skills. A prototype test bench has been built and experimentally validated to perform practical lessons of thermoelectric generation and refrigeration. Using this prototype students learn the most effective way of cooling systems and thermal power generation as well as basic concepts associated with thermoelectricity. It has been proven that students learn the process of data acquisition, and the technology used in thermoelectric devices. These practical lessons are implemented for a 60 people group of students in the development of subject of Thermodynamic including in the Degree in Engineering in Industrial Technologies of Public University of Navarra. Normal 0 21 false false false ES X-NONE X-NONE Normal 0 21 false false false ES X-NONE X-NONE Validation of simulation models

DEFF Research Database (Denmark)

Rehman, Muniza; Pedersen, Stig Andur

2012-01-01

In philosophy of science, the interest for computational models and simulations has increased heavily during the past decades. Different positions regarding the validity of models have emerged but the views have not succeeded in capturing the diversity of validation methods. The wide variety...

Inductive & Deductive Science Thinking: A Model for Lesson Development

Science.gov (United States)

Bilica, Kim; Flores, Margaret

2009-01-01

Middle school students make great learning gains when they participate in lessons that invite them to practice their developing scientific reasoning skills; however, designing developmentally appropriate, clear, and structured lessons about scientific thinking and reasoning can be difficult. This challenge can be met through lessons that teach…

Modelling the deposition of airborne radionuclides into the urban environment. First report of the VAMP Urban Working Group. Part of the IAEA/CEC co-ordinated research programme on the validation of environmental model predictions (VAMP)

International Nuclear Information System (INIS)

1994-08-01

A co-ordinated research programme was begun at the IAEA in 1988 with the short title of Validation of Environmental Model Predictions (VAMP). The VAMP Urban Working Group aims to examine, by means of expert review combined with formal validation exercises, modelling for the assessment of the radiation exposure of urban populations through the external irradiation and inhalation pathways. An aim of the studies is to evaluate the lessons learned and to document the improvements in modelling capability as a result of experience gained following the Chernobyl accident. This Technical Document, the first report of the Group, addresses the subject of the deposition of airborne radionuclides into the urban environment. It summarizes not only the present status of modelling in this field, but also the results of a limited validation exercise that was performed under the auspices of VAMP. 42 refs, figs and tabs

Opening the black box of energy modelling: Strategies and lessons learned

DEFF Research Database (Denmark)

Pfenninger, Stefan; Hirth, Lion; Schlecht, Ingmar

2018-01-01

and appropriate modelling languages, distributing code and data, and providing support and building communities. After illustrating these decisions with examples and lessons learned from the community, we conclude that even though individual researchers' choices are important, institutional changes are still also...

Test-driven verification/validation of model transformations

Institute of Scientific and Technical Information of China (English)

László LENGYEL; Hassan CHARAF

2015-01-01

Why is it important to verify/validate model transformations? The motivation is to improve the quality of the trans-formations, and therefore the quality of the generated software artifacts. Verified/validated model transformations make it possible to ensure certain properties of the generated software artifacts. In this way, verification/validation methods can guarantee different requirements stated by the actual domain against the generated/modified/optimized software products. For example, a verified/ validated model transformation can ensure the preservation of certain properties during the model-to-model transformation. This paper emphasizes the necessity of methods that make model transformation verified/validated, discusses the different scenarios of model transformation verification and validation, and introduces the principles of a novel test-driven method for verifying/ validating model transformations. We provide a solution that makes it possible to automatically generate test input models for model transformations. Furthermore, we collect and discuss the actual open issues in the field of verification/validation of model transformations.

Designing a lessons learned model to improve the success of new product development in project oriented organizations

Directory of Open Access Journals (Sweden)

Ahmad

2016-12-01

Full Text Available Nowadays, project-based organizations need to utilize intellectual capital and knowledge to become leader in their business activities. The new approach to use knowledge based skills from one side and development of the new complicated products from the other side have increased the need for designing a lessons learned model. The purpose of this paper is to design a lessons learned model to improve the success of new product development for project oriented organizations. The study designs a questionnaire in Likert scale and distributes it among 56 experts who were well informed about various techniques of new product development and lessons learned. Cronbach alphas for all components of the survey were well above the desirable level. The results of the survey have indicated that there were positive and meaningful relationships between lessons learned components and the success of the new product development.

Model validation and calibration based on component functions of model output

International Nuclear Information System (INIS)

Wu, Danqing; Lu, Zhenzhou; Wang, Yanping; Cheng, Lei

2015-01-01

The target in this work is to validate the component functions of model output between physical observation and computational model with the area metric. Based on the theory of high dimensional model representations (HDMR) of independent input variables, conditional expectations are component functions of model output, and the conditional expectations reflect partial information of model output. Therefore, the model validation of conditional expectations tells the discrepancy between the partial information of the computational model output and that of the observations. Then a calibration of the conditional expectations is carried out to reduce the value of model validation metric. After that, a recalculation of the model validation metric of model output is taken with the calibrated model parameters, and the result shows that a reduction of the discrepancy in the conditional expectations can help decrease the difference in model output. At last, several examples are employed to demonstrate the rationality and necessity of the methodology in case of both single validation site and multiple validation sites. - Highlights: • A validation metric of conditional expectations of model output is proposed. • HDRM explains the relationship of conditional expectations and model output. • An improved approach of parameter calibration updates the computational models. • Validation and calibration process are applied at single site and multiple sites. • Validation and calibration process show a superiority than existing methods

HEDR model validation plan

International Nuclear Information System (INIS)

Napier, B.A.; Gilbert, R.O.; Simpson, J.C.; Ramsdell, J.V. Jr.; Thiede, M.E.; Walters, W.H.

1993-06-01

The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computational ''tools'' for estimating the possible radiation dose that individuals may have received from past Hanford Site operations. This document describes the planned activities to ''validate'' these tools. In the sense of the HEDR Project, ''validation'' is a process carried out by comparing computational model predictions with field observations and experimental measurements that are independent of those used to develop the model

Validation of models with multivariate output

International Nuclear Information System (INIS)

Rebba, Ramesh; Mahadevan, Sankaran

2006-01-01

This paper develops metrics for validating computational models with experimental data, considering uncertainties in both. A computational model may generate multiple response quantities and the validation experiment might yield corresponding measured values. Alternatively, a single response quantity may be predicted and observed at different spatial and temporal points. Model validation in such cases involves comparison of multiple correlated quantities. Multiple univariate comparisons may give conflicting inferences. Therefore, aggregate validation metrics are developed in this paper. Both classical and Bayesian hypothesis testing are investigated for this purpose, using multivariate analysis. Since, commonly used statistical significance tests are based on normality assumptions, appropriate transformations are investigated in the case of non-normal data. The methodology is implemented to validate an empirical model for energy dissipation in lap joints under dynamic loading

A GUIDED SWAT MODEL APPLICATION ON SEDIMENT YIELD MODELING IN PANGANI RIVER BASIN: LESSONS LEARNT

Directory of Open Access Journals (Sweden)

Preksedis Marco Ndomba

2008-12-01

Full Text Available The overall objective of this paper is to report on the lessons learnt from applying Soil and Water Assessment Tool (SWAT in a well guided sediment yield modelling study. The study area is the upstream of Pangani River Basin (PRB, the Nyumba Ya Mungu (NYM reservoir catchment, located in the North Eastern part of Tanzania. It should be noted that, previous modeling exercises in the region applied SWAT with preassumption that inter-rill or sheet erosion was the dominant erosion type. In contrast, in this study SWAT model application was guided by results of analysis of high temporal resolution of sediment flow data and hydro-meteorological data. The runoff component of the SWAT model was calibrated from six-years (i.e. 1977–1982 of historical daily streamflow data. The sediment component of the model was calibrated using one-year (1977–1988 daily sediment loads estimated from one hydrological year sampling programme (between March and November, 2005 rating curve. A long-term period over 37 years (i.e. 1969–2005 simulation results of the SWAT model was validated to downstream NYM reservoir sediment accumulation information. The SWAT model captured 56 percent of the variance (CE and underestimated the observed daily sediment loads by 0.9 percent according to Total Mass Control (TMC performance indices during a normal wet hydrological year, i.e., between November 1, 1977 and October 31, 1978, as the calibration period. SWAT model predicted satisfactorily the long-term sediment catchment yield with a relative error of 2.6 percent. Also, the model has identified erosion sources spatially and has replicated some erosion processes as determined in other studies and field observations in the PRB. This result suggests that for catchments where sheet erosion is dominant SWAT model may substitute the sediment-rating curve. However, the SWAT model could not capture the dynamics of sediment load delivery in some seasons to the catchment outlet.

A GUIDED SWAT MODEL APPLICATION ON SEDIMENT YIELD MODELING IN PANGANI RIVER BASIN: LESSONS LEARNT

Directory of Open Access Journals (Sweden)

Preksedis M. Ndomba

2008-01-01

Full Text Available The overall objective of this paper is to report on the lessons learnt from applying Soil and Water Assessment Tool (SWAT in a well guided sediment yield modelling study. The study area is the upstream of Pangani River Basin (PRB, the Nyumba Ya Mungu (NYM reservoir catchment, located in the North Eastern part of Tanzania. It should be noted that, previous modeling exercises in the region applied SWAT with preassumption that inter-rill or sheet erosion was the dominant erosion type. In contrast, in this study SWAT model application was guided by results of analysis of high temporal resolution of sediment flow data and hydro-meteorological data. The runoff component of the SWAT model was calibrated from six-years (i.e. 1977¿1982 of historical daily streamflow data. The sediment component of the model was calibrated using one-year (1977-1988 daily sediment loads estimated from one hydrological year sampling programme (between March and November, 2005 rating curve. A long-term period over 37 years (i.e. 1969-2005 simulation results of the SWAT model was validated to downstream NYM reservoir sediment accumulation information. The SWAT model captured 56 percent of the variance (CE and underestimated the observed daily sediment loads by 0.9 percent according to Total Mass Control (TMC performance indices during a normal wet hydrological year, i.e., between November 1, 1977 and October 31, 1978, as the calibration period. SWAT model predicted satisfactorily the long-term sediment catchment yield with a relative error of 2.6 percent. Also, the model has identified erosion sources spatially and has replicated some erosion processes as determined in other studies and field observations in the PRB. This result suggests that for catchments where sheet erosion is dominant SWAT model may substitute the sediment-rating curve. However, the SWAT model could not capture the dynamics of sediment load delivery in some seasons to the catchment outlet.

Model Validation in Ontology Based Transformations

Directory of Open Access Journals (Sweden)

Jesús M. Almendros-Jiménez

2012-10-01

Full Text Available Model Driven Engineering (MDE is an emerging approach of software engineering. MDE emphasizes the construction of models from which the implementation should be derived by applying model transformations. The Ontology Definition Meta-model (ODM has been proposed as a profile for UML models of the Web Ontology Language (OWL. In this context, transformations of UML models can be mapped into ODM/OWL transformations. On the other hand, model validation is a crucial task in model transformation. Meta-modeling permits to give a syntactic structure to source and target models. However, semantic requirements have to be imposed on source and target models. A given transformation will be sound when source and target models fulfill the syntactic and semantic requirements. In this paper, we present an approach for model validation in ODM based transformations. Adopting a logic programming based transformational approach we will show how it is possible to transform and validate models. Properties to be validated range from structural and semantic requirements of models (pre and post conditions to properties of the transformation (invariants. The approach has been applied to a well-known example of model transformation: the Entity-Relationship (ER to Relational Model (RM transformation.

International casemix and funding models: lessons for rehabilitation.

Science.gov (United States)

Turner-Stokes, Lynne; Sutch, Stephen; Dredge, Robert; Eagar, Kathy

2012-03-01

This series of articles for rehabilitation in practice aims to cover a knowledge element of the rehabilitation medicine curriculum. Nevertheless they are intended to be of interest to a multidisciplinary audience. The competency addressed in this article is 'An understanding of the different international models for funding of health care services and casemix systems, as exemplified by those in the US, Australia and the UK.' Payment for treatment in healthcare systems around the world is increasingly based on fixed tariff models to drive up efficiency and contain costs. Casemix classifications, however, must account adequately for the resource implications of varying case complexity. Rehabilitation poses some particular challenges for casemix development. The objectives of this educational narrative review are (a) to provide an overview of the development of casemix in rehabilitation, (b) to describe key characteristics of some well-established casemix and payment models in operation around the world and (c) to explore opportunities for future development arising from the lessons learned. Diagnosis alone does not adequately describe cost variation in rehabilitation. Functional dependency is considered a better cost indicator, and casemix classifications for inpatient rehabilitation in the United States and Australia rely on the Functional Independence Measure (FIM). Fixed episode-based prospective payment systems are shown to contain costs, but at the expense of poorer functional outcomes. More sophisticated models incorporating a mixture of episode and weighted per diem rates may offer greater flexibility to optimize outcome, while still providing incentive for throughput. The development of casemix in rehabilitation poses similar challenges for healthcare systems all around the world. Well-established casemix systems in the United States and Australia have afforded valuable lessons for other countries to learn from, but have not provided all the answers. A range

Lessons learned from the CEOG generic accident management guidelines confirmation (validation) exercise

International Nuclear Information System (INIS)

Khalil, Y.F.; Schneider, R.E.; Greene, M.A.

1996-01-01

In July 1995, the CE Owner's Group completed and issued Revision 0 of the Generic Accident Management Guidelines (AMG's) to the owners group task participants. This guidance provides a structured mechanism for the plant staff at CE utilities to respond to accidents that beyond the plant design basis and, possibly, the Emergency Operating Procedures. Prior to final issue of the generic AMGs, the CEOG conducted an AMG Confirmation Exercise to establish the ability of the AMGs to fulfill this important role. The specific objectives of the AMG Confirmation Exercise were to (1) clarify the interactions and transitions between the AMG/Technical Support Center (TSC) and the EOPS/Operations Personnel (2) validate the adequacy of the AMG data collection and plant condition diagnostic evaluation process and (3) assess the feasibility of the mechanical material and recommendations contained in the AMG's. The purpose of paper is to provide a detailed description of the AMG Confirmation Exercise as well as important lessons learned during the planning and implementation of the exercise. In addition, a discussion will be presented pertaining to the relationship between the AMG's (incumbent to the Technical Support Center) and the plants Emergency Operating Procedures (incumbent to the Control Room Operations Staff)

Ground-water models: Validate or invalidate

Science.gov (United States)

Bredehoeft, J.D.; Konikow, Leonard F.

1993-01-01

The word validation has a clear meaning to both the scientific community and the general public. Within the scientific community the validation of scientific theory has been the subject of philosophical debate. The philosopher of science, Karl Popper, argued that scientific theory cannot be validated, only invalidated. Popper’s view is not the only opinion in this debate; however, many scientists today agree with Popper (including the authors). To the general public, proclaiming that a ground-water model is validated carries with it an aura of correctness that we do not believe many of us who model would claim. We can place all the caveats we wish, but the public has its own understanding of what the word implies. Using the word valid with respect to models misleads the public; verification carries with it similar connotations as far as the public is concerned. Our point is this: using the terms validation and verification are misleading, at best. These terms should be abandoned by the ground-water community.

A broad view of model validation

International Nuclear Information System (INIS)

Tsang, C.F.

1989-10-01

The safety assessment of a nuclear waste repository requires the use of models. Such models need to be validated to ensure, as much as possible, that they are a good representation of the actual processes occurring in the real system. In this paper we attempt to take a broad view by reviewing step by step the modeling process and bringing out the need to validating every step of this process. This model validation includes not only comparison of modeling results with data from selected experiments, but also evaluation of procedures for the construction of conceptual models and calculational models as well as methodologies for studying data and parameter correlation. The need for advancing basic scientific knowledge in related fields, for multiple assessment groups, and for presenting our modeling efforts in open literature to public scrutiny is also emphasized. 16 refs

Model performance analysis and model validation in logistic regression

Directory of Open Access Journals (Sweden)

Rosa Arboretti Giancristofaro

2007-10-01

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

Establishing model credibility involves more than validation

International Nuclear Information System (INIS)

Kirchner, T.

1991-01-01

One widely used definition of validation is that the quantitative test of the performance of a model through the comparison of model predictions to independent sets of observations from the system being simulated. The ability to show that the model predictions compare well with observations is often thought to be the most rigorous test that can be used to establish credibility for a model in the scientific community. However, such tests are only part of the process used to establish credibility, and in some cases may be either unnecessary or misleading. Naylor and Finger extended the concept of validation to include the establishment of validity for the postulates embodied in the model and the test of assumptions used to select postulates for the model. Validity of postulates is established through concurrence by experts in the field of study that the mathematical or conceptual model contains the structural components and mathematical relationships necessary to adequately represent the system with respect to the goals for the model. This extended definition of validation provides for consideration of the structure of the model, not just its performance, in establishing credibility. Evaluation of a simulation model should establish the correctness of the code and the efficacy of the model within its domain of applicability. (24 refs., 6 figs.)

Investigating Island Evolution: A Galapagos-Based Lesson Using the 5E Instructional Model.

Science.gov (United States)

DeFina, Anthony V.

2002-01-01

Introduces an inquiry-based lesson plan on evolution and the Galapagos Islands. Uses the 5E instructional model which includes phases of engagement, exploration, explanation, elaboration, and evaluation. Includes information on species for exploration and elaboration purposes, and a general rubric for student evaluation. (YDS)

Towards policy relevant environmental modeling: contextual validity and pragmatic models

Science.gov (United States)

Miles, Scott B.

2000-01-01

"What makes for a good model?" In various forms, this question is a question that, undoubtedly, many people, businesses, and institutions ponder with regards to their particular domain of modeling. One particular domain that is wrestling with this question is the multidisciplinary field of environmental modeling. Examples of environmental models range from models of contaminated ground water flow to the economic impact of natural disasters, such as earthquakes. One of the distinguishing claims of the field is the relevancy of environmental modeling to policy and environment-related decision-making in general. A pervasive view by both scientists and decision-makers is that a "good" model is one that is an accurate predictor. Thus, determining whether a model is "accurate" or "correct" is done by comparing model output to empirical observations. The expected outcome of this process, usually referred to as "validation" or "ground truthing," is a stamp on the model in question of "valid" or "not valid" that serves to indicate whether or not the model will be reliable before it is put into service in a decision-making context. In this paper, I begin by elaborating on the prevailing view of model validation and why this view must change. Drawing from concepts coming out of the studies of science and technology, I go on to propose a contextual view of validity that can overcome the problems associated with "ground truthing" models as an indicator of model goodness. The problem of how we talk about and determine model validity has much to do about how we perceive the utility of environmental models. In the remainder of the paper, I argue that we should adopt ideas of pragmatism in judging what makes for a good model and, in turn, developing good models. From such a perspective of model goodness, good environmental models should facilitate communication, convey—not bury or "eliminate"—uncertainties, and, thus, afford the active building of consensus decisions, instead

Statistical validation of normal tissue complication probability models.

Science.gov (United States)

Xu, Cheng-Jian; van der Schaaf, Arjen; Van't Veld, Aart A; Langendijk, Johannes A; Schilstra, Cornelis

2012-09-01

To investigate the applicability and value of double cross-validation and permutation tests as established statistical approaches in the validation of normal tissue complication probability (NTCP) models. A penalized regression method, LASSO (least absolute shrinkage and selection operator), was used to build NTCP models for xerostomia after radiation therapy treatment of head-and-neck cancer. Model assessment was based on the likelihood function and the area under the receiver operating characteristic curve. Repeated double cross-validation showed the uncertainty and instability of the NTCP models and indicated that the statistical significance of model performance can be obtained by permutation testing. Repeated double cross-validation and permutation tests are recommended to validate NTCP models before clinical use. Copyright © 2012 Elsevier Inc. All rights reserved.

Statistical Validation of Normal Tissue Complication Probability Models

Energy Technology Data Exchange (ETDEWEB)

Xu Chengjian, E-mail: c.j.xu@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Schaaf, Arjen van der; Veld, Aart A. van' t; Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Schilstra, Cornelis [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Radiotherapy Institute Friesland, Leeuwarden (Netherlands)

2012-09-01

Purpose: To investigate the applicability and value of double cross-validation and permutation tests as established statistical approaches in the validation of normal tissue complication probability (NTCP) models. Methods and Materials: A penalized regression method, LASSO (least absolute shrinkage and selection operator), was used to build NTCP models for xerostomia after radiation therapy treatment of head-and-neck cancer. Model assessment was based on the likelihood function and the area under the receiver operating characteristic curve. Results: Repeated double cross-validation showed the uncertainty and instability of the NTCP models and indicated that the statistical significance of model performance can be obtained by permutation testing. Conclusion: Repeated double cross-validation and permutation tests are recommended to validate NTCP models before clinical use.

Validation process of simulation model

International Nuclear Information System (INIS)

San Isidro, M. J.

1998-01-01

It is presented a methodology on empirical validation about any detailed simulation model. This king of validation it is always related with an experimental case. The empirical validation has a residual sense, because the conclusions are based on comparisons between simulated outputs and experimental measurements. This methodology will guide us to detect the fails of the simulation model. Furthermore, it can be used a guide in the design of posterior experiments. Three steps can be well differentiated: Sensitivity analysis. It can be made with a DSA, differential sensitivity analysis, and with a MCSA, Monte-Carlo sensitivity analysis. Looking the optimal domains of the input parameters. It has been developed a procedure based on the Monte-Carlo methods and Cluster techniques, to find the optimal domains of these parameters. Residual analysis. This analysis has been made on the time domain and on the frequency domain, it has been used the correlation analysis and spectral analysis. As application of this methodology, it is presented the validation carried out on a thermal simulation model on buildings, Esp., studying the behavior of building components on a Test Cell of LECE of CIEMAT. (Author) 17 refs

A proposed best practice model validation framework for banks

Directory of Open Access Journals (Sweden)

Pieter J. (Riaan de Jongh

2017-06-01

Full Text Available Background: With the increasing use of complex quantitative models in applications throughout the financial world, model risk has become a major concern. The credit crisis of 2008–2009 provoked added concern about the use of models in finance. Measuring and managing model risk has subsequently come under scrutiny from regulators, supervisors, banks and other financial institutions. Regulatory guidance indicates that meticulous monitoring of all phases of model development and implementation is required to mitigate this risk. Considerable resources must be mobilised for this purpose. The exercise must embrace model development, assembly, implementation, validation and effective governance. Setting: Model validation practices are generally patchy, disparate and sometimes contradictory, and although the Basel Accord and some regulatory authorities have attempted to establish guiding principles, no definite set of global standards exists. Aim: Assessing the available literature for the best validation practices. Methods: This comprehensive literature study provided a background to the complexities of effective model management and focussed on model validation as a component of model risk management. Results: We propose a coherent ‘best practice’ framework for model validation. Scorecard tools are also presented to evaluate if the proposed best practice model validation framework has been adequately assembled and implemented. Conclusion: The proposed best practice model validation framework is designed to assist firms in the construction of an effective, robust and fully compliant model validation programme and comprises three principal elements: model validation governance, policy and process.

Innovation in the management of lessons learned in an IT project with the adoption of social media

Directory of Open Access Journals (Sweden)

Roberto Winter

2017-03-01

Full Text Available This research explores the gap in the management of lessons learned (MLL in an Information Technology project (IT, validating a model (named Target with the support of a wiki platform in a medium-sized company in the IT industry. This model supports the following MLL processes: awareness, collection, verification, storage, dissemination and reuse. This study adopts the paradigm of the Design Science Research and the Technical Action Research method to instantiate the Target model in the implementation phase of an IT project. The theoretical contribution lies in the practical utility of an LL model, which was validated in the field promoting innovation in the MLL. The practical implications can be seen in the company's learning to introduce the MLL, improve design productivity, increase employee collaboration and better disseminate knowledge.

How Best to Obtain Valid, Verifiable Data Online From Male Couples? Lessons Learned From an eHealth HIV Prevention Intervention for HIV-Negative Male Couples.

Science.gov (United States)

Mitchell, Jason; Lee, Ji-Young; Stephenson, Rob

2016-09-20

As interest increases in the development of eHealth human immunodeficiency virus (HIV)-preventive interventions for gay male couples, Web-based methods must also be developed to help increase the likelihood that couples enrolled and data collected from them represent true unique dyads. Methods to recruit and collect reliable and valid data from both members of a couple are lacking, yet are crucial for uptake of novel sexual health and HIV-prevention eHealth interventions. Methods to describe best practices to recruit male couples using targeted advertisements on Facebook are also lacking in the literature, yet could also help in this uptake. The objective of our study was to describe challenges and lessons learned from experiences from two phases (developmental phase and online randomized controlled trial [RCT]) of an eHealth HIV-prevention intervention for concordant HIV-negative male couples in terms of (1) recruiting male couples using targeted advertisements on Facebook, (2) validating that data came from two partners of the couple, and (3) verifying that the two partners of the couple are in a relationship with each other. The developmental phase refined the intervention via in-person focus groups, whereas the pilot-testing phase included an online RCT. For both phases, couples were recruited via targeted Facebook advertisements. Advertisements directed men to a study webpage and screener; once eligible, participants provided consent electronically. A partner referral system was embedded in the consenting process to recruit the relationship partner of the participant. Both men of the couple had to meet all eligibility criteria-individually and as a couple-before they could enroll in the study. Verification of couples' relationships was assessed via the concurrence of predetermined screener items from both partners, done manually in the developmental phase and electronically in the pilot-testing phase. A system of decision rules was developed to assess the

Statistical Validation of Engineering and Scientific Models: Background

International Nuclear Information System (INIS)

Hills, Richard G.; Trucano, Timothy G.

1999-01-01

A tutorial is presented discussing the basic issues associated with propagation of uncertainty analysis and statistical validation of engineering and scientific models. The propagation of uncertainty tutorial illustrates the use of the sensitivity method and the Monte Carlo method to evaluate the uncertainty in predictions for linear and nonlinear models. Four example applications are presented; a linear model, a model for the behavior of a damped spring-mass system, a transient thermal conduction model, and a nonlinear transient convective-diffusive model based on Burger's equation. Correlated and uncorrelated model input parameters are considered. The model validation tutorial builds on the material presented in the propagation of uncertainty tutoriaI and uses the damp spring-mass system as the example application. The validation tutorial illustrates several concepts associated with the application of statistical inference to test model predictions against experimental observations. Several validation methods are presented including error band based, multivariate, sum of squares of residuals, and optimization methods. After completion of the tutorial, a survey of statistical model validation literature is presented and recommendations for future work are made

Model Validation Using Coordinate Distance with Performance Sensitivity

Directory of Open Access Journals (Sweden)

Jiann-Shiun Lew

2008-01-01

Full Text Available This paper presents an innovative approach to model validation for a structure with significant parameter variations. Model uncertainty of the structural dynamics is quantified with the use of a singular value decomposition technique to extract the principal components of parameter change, and an interval model is generated to represent the system with parameter uncertainty. The coordinate vector, corresponding to the identified principal directions, of the validation system is computed. The coordinate distance between the validation system and the identified interval model is used as a metric for model validation. A beam structure with an attached subsystem, which has significant parameter uncertainty, is used to demonstrate the proposed approach.

Some considerations for validation of repository performance assessment models

International Nuclear Information System (INIS)

Eisenberg, N.

1991-01-01

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

SDG and qualitative trend based model multiple scale validation

Science.gov (United States)

Gao, Dong; Xu, Xin; Yin, Jianjin; Zhang, Hongyu; Zhang, Beike

2017-09-01

Verification, Validation and Accreditation (VV&A) is key technology of simulation and modelling. For the traditional model validation methods, the completeness is weak; it is carried out in one scale; it depends on human experience. The SDG (Signed Directed Graph) and qualitative trend based multiple scale validation is proposed. First the SDG model is built and qualitative trends are added to the model. And then complete testing scenarios are produced by positive inference. The multiple scale validation is carried out by comparing the testing scenarios with outputs of simulation model in different scales. Finally, the effectiveness is proved by carrying out validation for a reactor model.

Sustainable solar home systems model: Applying lessons from Bangladesh to Myanmar's rural poor

DEFF Research Database (Denmark)

Newcombe, Alex; Ackom, Emmanuel

2017-01-01

Myanmar's rural population has very low access to electricity, mainly due to low disposal income and the remoteness of communities. This paper attempts to test the potential applicability of Grameen Shakti-Infrastructure Development Company Limited (IDCOL), which is a Bangladeshi public private...... partnership microfinance model, to rural Myanmar towards enhanced solar home systems (SHS) deployment. Rural poor are enabled by this microfinancing scheme to own SHSs in a few years for as low as US$6.40 per month. The objectives of this paper are to assess the experience of Grameen Shakti-IDCOL and other...... similar projects for invaluable lessons, identify barriers to sustainable electrification for Myanmar's rural poor and to apply these lessons learned to overcome barriers by developing policy recommendations for sustainable electrification for rural poor in Myanmar. Recommendations are provided suggesting...

Validating EHR clinical models using ontology patterns.

Science.gov (United States)

Martínez-Costa, Catalina; Schulz, Stefan

2017-12-01

Clinical models are artefacts that specify how information is structured in electronic health records (EHRs). However, the makeup of clinical models is not guided by any formal constraint beyond a semantically vague information model. We address this gap by advocating ontology design patterns as a mechanism that makes the semantics of clinical models explicit. This paper demonstrates how ontology design patterns can validate existing clinical models using SHACL. Based on the Clinical Information Modelling Initiative (CIMI), we show how ontology patterns detect both modeling and terminology binding errors in CIMI models. SHACL, a W3C constraint language for the validation of RDF graphs, builds on the concept of "Shape", a description of data in terms of expected cardinalities, datatypes and other restrictions. SHACL, as opposed to OWL, subscribes to the Closed World Assumption (CWA) and is therefore more suitable for the validation of clinical models. We have demonstrated the feasibility of the approach by manually describing the correspondences between six CIMI clinical models represented in RDF and two SHACL ontology design patterns. Using a Java-based SHACL implementation, we found at least eleven modeling and binding errors within these CIMI models. This demonstrates the usefulness of ontology design patterns not only as a modeling tool but also as a tool for validation. Copyright © 2017 Elsevier Inc. All rights reserved.

Tracer travel time and model validation

International Nuclear Information System (INIS)

Tsang, Chin-Fu.

1988-01-01

The performance assessment of a nuclear waste repository demands much more in comparison to the safety evaluation of any civil constructions such as dams, or the resource evaluation of a petroleum or geothermal reservoir. It involves the estimation of low probability (low concentration) of radionuclide transport extrapolated 1000's of years into the future. Thus models used to make these estimates need to be carefully validated. A number of recent efforts have been devoted to the study of this problem. Some general comments on model validation were given by Tsang. The present paper discusses some issues of validation in regards to radionuclide transport. 5 refs

Model validation: a systemic and systematic approach

International Nuclear Information System (INIS)

Sheng, G.; Elzas, M.S.; Cronhjort, B.T.

1993-01-01

The term 'validation' is used ubiquitously in association with the modelling activities of numerous disciplines including social, political natural, physical sciences, and engineering. There is however, a wide range of definitions which give rise to very different interpretations of what activities the process involves. Analyses of results from the present large international effort in modelling radioactive waste disposal systems illustrate the urgent need to develop a common approach to model validation. Some possible explanations are offered to account for the present state of affairs. The methodology developed treats model validation and code verification in a systematic fashion. In fact, this approach may be regarded as a comprehensive framework to assess the adequacy of any simulation study. (author)

MODEL PEMBELAJARAN PROBLEM POSING DENGAN PENDEKATAN SAINTIFIK UNTUK MENINGKATKAN KEMAMPUAN PEMECAHAN MASALAH

Directory of Open Access Journals (Sweden)

Adi Purnomo

2015-08-01

Full Text Available Tujuan penelitian ini untuk menghasilkan perangkat pembelajaran model problem posing pendekatan saintifik yang valid, praktis dan efektif. Penelitian ini merupakan penelitian pengembangan dengan model Thiagarajan. Pengolahan data penelitian untuk uji kevalidan dan kepraktisan dilakukan dengan menghitung rata-rata skor, sedangkan uji keefektifan dilakukan dengan uji t, uji proporsi, uji regresi, uji t berpasangan, dan uji normalitas gain. Hasil pengembangan diperoleh perangkat pembelajaran dinyatakan valid dengan rata-rata skor validasi silabus 4,3, RPP 4,31, buku peserta didik 4,24, LKPD 4,16, TKPM 4,19, dari skor maksimal 5,00. Perangkat pembelajaran praktis berdasarkan hasil pengamatan kemampuan guru 4,5 (sangat baik dan respon peserta didik 3,8 (baik. Implementasi perangkat pembelajaran efektif yang ditunjukkan dengan: (1 ketuntasan klasikal TKKM melampaui 75%, rata-rata kelas melampaui KKM; (2 kemampuan pemecahan masalah peserta didik yang pembelajarannya menggunakan model problrm posing pendekatan saintifik lebih baik dari pada peserta didik dengan pembelajaran konvensional; (3 keterampilan proses saintifik dan karakter kemandirian berpengaruh positif terhadap kemampuan pemecahan masalah; dan (4 adanya peningkatan pemecahan masalah dan mendiskripsikan peningkatan kemampuan pemecahan masalah berdasarkan Taksonomi SOLO.The purpose of this research to development lesson plan through problem posing model with scientific approach which are valid, practical, and effective. The development research using Thiagarajan model. Processing data for validation and practice can be done calculating the score average, while effectivity by use of t-test, proportion test, regression test, paired t-test, n-gain. The lesson plan is valid based on the average of validation scores syllabus 4,3, RPP 4,31, student book 4,24, LKPD 4,16, TKPM 4,19.  The lesson plan is practical based on the result of observation teacher ability 4,53 and student response 4,23. The

Validation of models in an imaging infrared simulation

CSIR Research Space (South Africa)

Willers, C

2007-10-01

Full Text Available threeprocessesfortransformingtheinformationbetweentheentities. Reality/ Problem Entity Conceptual Model Computerized Model Model Validation ModelVerification Model Qualification Computer Implementation Analysisand Modelling Simulationand Experimentation “Substantiationthata....C.Refsgaard ,ModellingGuidelines-terminology andguidingprinciples, AdvancesinWaterResources, Vol27,No1,January2004,?pp.71-82(12),Elsevier. et.al. [5]N.Oreskes,et.al.,Verification,Validation,andConfirmationof NumericalModelsintheEarthSciences,Science,Vol263, Number...

Simulating classroom lessons : an agent-based attempt

OpenAIRE

Ingram, Fred; Brooks, Roger John

2018-01-01

This is an interim report on a project to construct an agent-based simulation that reproduces some of the interactions between students and their teacher in classroom lessons. In a pilot study, the activities of 67 students and 7 teachers during 40 lessons were recorded using a data collection instrument that currently captures 17 student states and 15 teacher states. These data enabled various conceptual models to be explored, providing empirical values and distributions for the model parame...

Feature Extraction for Structural Dynamics Model Validation

Energy Technology Data Exchange (ETDEWEB)

Farrar, Charles [Los Alamos National Laboratory; Nishio, Mayuko [Yokohama University; Hemez, Francois [Los Alamos National Laboratory; Stull, Chris [Los Alamos National Laboratory; Park, Gyuhae [Chonnam Univesity; Cornwell, Phil [Rose-Hulman Institute of Technology; Figueiredo, Eloi [Universidade Lusófona; Luscher, D. J. [Los Alamos National Laboratory; Worden, Keith [University of Sheffield

2016-01-13

As structural dynamics becomes increasingly non-modal, stochastic and nonlinear, finite element model-updating technology must adopt the broader notions of model validation and uncertainty quantification. For example, particular re-sampling procedures must be implemented to propagate uncertainty through a forward calculation, and non-modal features must be defined to analyze nonlinear data sets. The latter topic is the focus of this report, but first, some more general comments regarding the concept of model validation will be discussed.

The concept of validation of numerical models for consequence analysis

International Nuclear Information System (INIS)

Borg, Audun; Paulsen Husted, Bjarne; Njå, Ove

2014-01-01

Numerical models such as computational fluid dynamics (CFD) models are increasingly used in life safety studies and other types of analyses to calculate the effects of fire and explosions. The validity of these models is usually established by benchmark testing. This is done to quantitatively measure the agreement between the predictions provided by the model and the real world represented by observations in experiments. This approach assumes that all variables in the real world relevant for the specific study are adequately measured in the experiments and in the predictions made by the model. In this paper the various definitions of validation for CFD models used for hazard prediction are investigated to assess their implication for consequence analysis in a design phase. In other words, how is uncertainty in the prediction of future events reflected in the validation process? The sources of uncertainty are viewed from the perspective of the safety engineer. An example of the use of a CFD model is included to illustrate the assumptions the analyst must make and how these affect the prediction made by the model. The assessments presented in this paper are based on a review of standards and best practice guides for CFD modeling and the documentation from two existing CFD programs. Our main thrust has been to assess how validation work is performed and communicated in practice. We conclude that the concept of validation adopted for numerical models is adequate in terms of model performance. However, it does not address the main sources of uncertainty from the perspective of the safety engineer. Uncertainty in the input quantities describing future events, which are determined by the model user, outweighs the inaccuracies in the model as reported in validation studies. - Highlights: • Examine the basic concept of validation applied to models for consequence analysis. • Review standards and guides for validation of numerical models. • Comparison of the validation

Validation of ASTEC core degradation and containment models

International Nuclear Information System (INIS)

Kruse, Philipp; Brähler, Thimo; Koch, Marco K.

2014-01-01

Ruhr-Universitaet Bochum performed in a German funded project validation of in-vessel and containment models of the integral code ASTEC V2, jointly developed by IRSN (France) and GRS (Germany). In this paper selected results of this validation are presented. In the in-vessel part, the main point of interest was the validation of the code capability concerning cladding oxidation and hydrogen generation. The ASTEC calculations of QUENCH experiments QUENCH-03 and QUENCH-11 show satisfactory results, despite of some necessary adjustments in the input deck. Furthermore, the oxidation models based on the Cathcart–Pawel and Urbanic–Heidrick correlations are not suitable for higher temperatures while the ASTEC model BEST-FIT based on the Prater–Courtright approach at high temperature gives reliable enough results. One part of the containment model validation was the assessment of three hydrogen combustion models of ASTEC against the experiment BMC Ix9. The simulation results of these models differ from each other and therefore the quality of the simulations depends on the characteristic of each model. Accordingly, the CPA FRONT model, corresponding to the simplest necessary input parameters, provides the best agreement to the experimental data

Analytical models approximating individual processes: a validation method.

Science.gov (United States)

Favier, C; Degallier, N; Menkès, C E

2010-12-01

Upscaling population models from fine to coarse resolutions, in space, time and/or level of description, allows the derivation of fast and tractable models based on a thorough knowledge of individual processes. The validity of such approximations is generally tested only on a limited range of parameter sets. A more general validation test, over a range of parameters, is proposed; this would estimate the error induced by the approximation, using the original model's stochastic variability as a reference. This method is illustrated by three examples taken from the field of epidemics transmitted by vectors that bite in a temporally cyclical pattern, that illustrate the use of the method: to estimate if an approximation over- or under-fits the original model; to invalidate an approximation; to rank possible approximations for their qualities. As a result, the application of the validation method to this field emphasizes the need to account for the vectors' biology in epidemic prediction models and to validate these against finer scale models. Copyright © 2010 Elsevier Inc. All rights reserved.

Validation of an instrument for mathematics enhancement teaching efficacy of Pacific Northwest agricultural educators

Science.gov (United States)

Jansen, Daniel J.

Teacher efficacy continues to be an important area of study in educational research. This study tested an instrument designed to assess the perceived efficacy of agricultural education teachers when engaged in lessons involving mathematics instruction. The study population of Oregon and Washington agricultural educators utilized in the validation of the instrument revealed important demographic findings and specific results related to teacher efficacy for the study population. An instrument was developed from the assimilation of three scales previously used and validated in efficacy research. Participants' mathematics teaching efficacy was assessed using a portion of the Mathematics Teaching Efficacy Beliefs Instrument (MTEBI), and personal mathematics efficacy was evaluated by the mathematics self-belief instrument which was derived from the Betz and Hackett's Mathematics Self-Efficacy Scale. The final scale, the Teachers' Sense of Efficacy Scale (TSES) created by Tschannen-Moran and Woolfolk Hoy, examined perceived personal teaching efficacy. Structural equation modeling was used as the statistical analyses tool to validate the instrument and examine correlations between efficacy constructs used to determine potential professional development needs of the survey population. As part of the data required for validation of the Mathematics Enhancement Teaching Efficacy instrument, demographic information defining the population of Oregon and Washington agricultural educators was obtained and reported. A hypothetical model derived from teacher efficacy literature was found to be an acceptable model to verify construct validity and determine strength of correlations between the scales that defined the instrument. The instrument produced an alpha coefficient of .905 for reliability. Both exploratory and confirmatory factor analyses were used to verify construct and discriminate validity. Specifics results related to the survey population of agricultural educators

A discussion on validation of hydrogeological models

International Nuclear Information System (INIS)

Carrera, J.; Mousavi, S.F.; Usunoff, E.J.; Sanchez-Vila, X.; Galarza, G.

1993-01-01

Groundwater flow and solute transport are often driven by heterogeneities that elude easy identification. It is also difficult to select and describe the physico-chemical processes controlling solute behaviour. As a result, definition of a conceptual model involves numerous assumptions both on the selection of processes and on the representation of their spatial variability. Validating a numerical model by comparing its predictions with actual measurements may not be sufficient for evaluating whether or not it provides a good representation of 'reality'. Predictions will be close to measurements, regardless of model validity, if these are taken from experiments that stress well-calibrated model modes. On the other hand, predictions will be far from measurements when model parameters are very uncertain, even if the model is indeed a very good representation of the real system. Hence, we contend that 'classical' validation of hydrogeological models is not possible. Rather, models should be viewed as theories about the real system. We propose to follow a rigorous modeling approach in which different sources of uncertainty are explicitly recognized. The application of one such approach is illustrated by modeling a laboratory uranium tracer test performed on fresh granite, which was used as Test Case 1b in INTRAVAL. (author)

Verification and validation for waste disposal models

International Nuclear Information System (INIS)

1987-07-01

A set of evaluation criteria has been developed to assess the suitability of current verification and validation techniques for waste disposal methods. A survey of current practices and techniques was undertaken and evaluated using these criteria with the items most relevant to waste disposal models being identified. Recommendations regarding the most suitable verification and validation practices for nuclear waste disposal modelling software have been made

A Mixed Methods Comparison of Teachers' Lunar Modeling Lesson Implementation and Student Learning Outcomes

Science.gov (United States)

Lamar, Mary F.; Wilhelm, Jennifer Anne; Cole, Merryn

2018-01-01

The authors compare three teachers' adaptations and implementation of a lunar modeling lesson to explain marked differences in student learning outcomes on a spatial-scientific lunar assessment. They used a modified version of the Practices of Science Observation Protocol (P-SOP; Forbes, Biggers, & Zangori, 2013) to identify ways in which…

Structural system identification: Structural dynamics model validation

Energy Technology Data Exchange (ETDEWEB)

Red-Horse, J.R.

1997-04-01

Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

Validating the passenger traffic model for Copenhagen

DEFF Research Database (Denmark)

Overgård, Christian Hansen; VUK, Goran

2006-01-01

The paper presents a comprehensive validation procedure for the passenger traffic model for Copenhagen based on external data from the Danish national travel survey and traffic counts. The model was validated for the years 2000 to 2004, with 2004 being of particular interest because the Copenhagen...... matched the observed traffic better than those of the transit assignment model. With respect to the metro forecasts, the model over-predicts metro passenger flows by 10% to 50%. The wide range of findings from the project resulted in two actions. First, a project was started in January 2005 to upgrade...

Bayesian risk-based decision method for model validation under uncertainty

International Nuclear Information System (INIS)

Jiang Xiaomo; Mahadevan, Sankaran

2007-01-01

This paper develops a decision-making methodology for computational model validation, considering the risk of using the current model, data support for the current model, and cost of acquiring new information to improve the model. A Bayesian decision theory-based method is developed for this purpose, using a likelihood ratio as the validation metric for model assessment. An expected risk or cost function is defined as a function of the decision costs, and the likelihood and prior of each hypothesis. The risk is minimized through correctly assigning experimental data to two decision regions based on the comparison of the likelihood ratio with a decision threshold. A Bayesian validation metric is derived based on the risk minimization criterion. Two types of validation tests are considered: pass/fail tests and system response value measurement tests. The methodology is illustrated for the validation of reliability prediction models in a tension bar and an engine blade subjected to high cycle fatigue. The proposed method can effectively integrate optimal experimental design into model validation to simultaneously reduce the cost and improve the accuracy of reliability model assessment

PENERAPAN LESSON STUDY UNTUK MENINGKATAN KEMAMPUAN MENGAJAR MAHASISWA CALON GURU FISIKA

Directory of Open Access Journals (Sweden)

Rif’ati Dina Handayani

2015-02-01

ABSTRAK Lesson study merupakan suatu model pengembangan kemampuan mengajar melalui pengkajian pembelajaran secara kolaboratif dan berkelanjutan. Lesson study dilaksanakan dalam tiga tahapan, yaitu plan, do, see yang dilaksanakan secara terstruktur, bersiklus dan berkelanjutan. Dalam penelitian ini subjek dari pelaksanaan lesson study adalah empat orang  mahasiswa calon guru fisika yang sedang melaksanakan PPL di salah satu SMP Negeri di Bondowoso. Hasil penelitian menunjukkan bahwa penerapan lesson study dapat meningkatkan kemampuan mengajar mahasiswa calon guru fisika dari kriteria kurang baik menjadi kriteria sangat baik. Kata kunci: Calon guru fisika, Lesson Study, Kemampuan Mengajar

Lessons learned bulletin

International Nuclear Information System (INIS)

1994-05-01

During the past four years, the Department of Energy -- Savannah River Operations Office and the Westinghouse Savannah River Company (WSRC) Environmental Restoration (ER) Program completed various activities ranging from waste site investigations to closure and post closure projects. Critiques for lessons learned regarding project activities are performed at the completion of each project milestone, and this critique interval allows for frequent recognition of lessons learned. In addition to project related lessons learned, ER also performs lessons learned critiques. T'he Savannah River Site (SRS) also obtains lessons learned information from general industry, commercial nuclear industry, naval nuclear programs, and other DOE sites within the complex. Procedures are approved to administer the lessons learned program, and a database is available to catalog applicable lessons learned regarding environmental remediation, restoration, and administrative activities. ER will continue to use this database as a source of information available to SRS personnel

Validation of mentorship model for newly qualified professional ...

African Journals Online (AJOL)

Newly qualified professional nurses (NQPNs) allocated to community health care services require the use of validated model to practice independently. Validation was done to adapt and assess if the model is understood and could be implemented by NQPNs and mentors employed in community health care services.

Validation and Adaptation of Router and Switch Models

NARCIS (Netherlands)

Boltjes, B.; Fernandez Diaz, I.; Kock, B.A.; Langeveld, R.J.G.M.; Schoenmaker, G.

2003-01-01

This paper describes validating OPNET models of key devices for the next generation IP-based tactical network of the Royal Netherlands Army (RNLA). The task of TNO-FEL is to provide insight in scalability and performance of future deployed networks. Because validated models ol key Cisco equipment

Project-Based Learning Using Discussion and Lesson-Learned Methods via Social Media Model for Enhancing Problem Solving Skills

Science.gov (United States)

Jewpanich, Chaiwat; Piriyasurawong, Pallop

2015-01-01

This research aims to 1) develop the project-based learning using discussion and lesson-learned methods via social media model (PBL-DLL SoMe Model) used for enhancing problem solving skills of undergraduate in education student, and 2) evaluate the PBL-DLL SoMe Model used for enhancing problem solving skills of undergraduate in education student.…

Reservation Application System Of Private Lesson At Easyspeak Denpasar Based On Web And Android

Directory of Open Access Journals (Sweden)

Ferry yudhitama putra

2016-06-01

Full Text Available Abstract— English Private lessons institutes are now widely facilitates a person to develop English skills in speaking and writing. Currently the service users private lessons English book private lessons manually, that is by coming directly to the place as well as through the telephone service, but with the operator even then still have difficulties in user validation that requires a long time. To facilitate the user in terms of the reservation, then the system will be built based on web and Android. Development of private lessons reservation application built with PHP and Java programming language using CodeIgniter framework on the web side , while on the Android using Eclipse tools , and MySQL as database storage media . Applications reservation private lessons has several functions to make a reservation time and tutor can be done by the student of Easyspeak and on the side of the tutor application can provide information about the student will be taught , as well as on the side of the operator to provide ease in setting booking private lessons because it computerized not manually as before. Applications reservation private lessons are also equipped with a reminder or reminders are made on the side of Android apps , using alarmmanager system.

The effectiveness of CCDSR learning model to improve skills of creating lesson plan and worksheet science process skill (SPS) for pre-service physics teacher

Science.gov (United States)

Limatahu, I.; Suyatno; Wasis; Prahani, B. K.

2018-03-01

In the previous research, CCDSR (Condition, Construction, Development, Simulation, and Reflection) learning model has been developed to improve science process skills for pre-service physics teacher. This research is aimed to analyze the effectiveness of CCDSR learning model towards the improvement skills of creating lesson plan and worksheet of Science Process Skill (SPS) for pre-service physics teacher in academic year 2016/2017. This research used one group pre-test and post-test design on 12 pre-service physics teacher at Physics Education, University of Khairun. Data collection was conducted through test and observation. Creating lesson plan and worksheet SPS skills of pre-service physics teacher measurement were conducted through Science Process Skill Evaluation Sheet (SPSES). The data analysis technique was done by Wilcoxon t-test and n-gain. The CCDSR learning model consists of 5 phases, including (1) Condition, (2) Construction, (3) Development, (4) Simulation, and (5) Reflection. The results showed that there was a significant increase in creating lesson plan and worksheet SPS skills of pre-service physics teacher at α = 5% and n-gain average of moderate category. Thus, the CCDSR learning model is effective for improving skills of creating lesson plan and worksheet SPS for pre-service physics teacher.

Development of a Conservative Model Validation Approach for Reliable Analysis

Science.gov (United States)

2015-01-01

CIE 2015 August 2-5, 2015, Boston, Massachusetts, USA [DRAFT] DETC2015-46982 DEVELOPMENT OF A CONSERVATIVE MODEL VALIDATION APPROACH FOR RELIABLE...obtain a conservative simulation model for reliable design even with limited experimental data. Very little research has taken into account the...3, the proposed conservative model validation is briefly compared to the conventional model validation approach. Section 4 describes how to account

MODIS Science Algorithms and Data Systems Lessons Learned

Science.gov (United States)

Wolfe, Robert E.; Ridgway, Bill L.; Patt, Fred S.; Masuoka, Edward J.

2009-01-01

For almost 10 years, standard global products from NASA's Earth Observing System s (EOS) two Moderate Resolution Imaging Spectroradiometer (MODIS) sensors are being used world-wide for earth science research and applications. This paper discusses the lessons learned in developing the science algorithms and the data systems needed to produce these high quality data products for the earth sciences community. Strong science team leadership and communication, an evolvable and scalable data system, and central coordination of QA and validation activities enabled the data system to grow by two orders of magnitude from the initial at-launch system to the current system able to reprocess data from both the Terra and Aqua missions in less than a year. Many of the lessons learned from MODIS are already being applied to follow-on missions.

Validation of ecological state space models using the Laplace approximation

DEFF Research Database (Denmark)

Thygesen, Uffe Høgsbro; Albertsen, Christoffer Moesgaard; Berg, Casper Willestofte

2017-01-01

Many statistical models in ecology follow the state space paradigm. For such models, the important step of model validation rarely receives as much attention as estimation or hypothesis testing, perhaps due to lack of available algorithms and software. Model validation is often based on a naive...... for estimation in general mixed effects models. Implementing one-step predictions in the R package Template Model Builder, we demonstrate that it is possible to perform model validation with little effort, even if the ecological model is multivariate, has non-linear dynamics, and whether observations...... useful directions in which the model could be improved....

Lessons learned from HRA and human-system modeling efforts

International Nuclear Information System (INIS)

Hallbert, B.P.

1993-01-01

Human-System modeling is not unique to the field of Human Reliability Analysis (HRA). Since human factors professionals first began their explorations of human activities, they have done so with the concept of open-quotes systemclose quotes in mind. Though the two - human and system - are distinct, they can be properly understood only in terms of each other: the system provides a context in which goals and objectives for work are defined, and the human plays either a pre-defined or ad hoc role in meeting these goals. In this sense, every intervention which attempts to evaluate or improve upon some system parameter requires that an understanding of human-system interactions be developed. It is too often the case, however, that somewhere between the inception of a system and its implementation, the human-system relationships are overlooked, misunderstood, or inadequately framed. This results in mismatches between demands versus capabilities of human operators, systems which are difficult to operate, and the obvious end product-human error. The lessons learned from human system modeling provide a valuable feedback mechanism to the process of HRA, and the technologies which employ this form of modeling

PENGEMBANGAN PERANGKAT PEMBELAJARAN IPA MODEL 5E DI SMP

Directory of Open Access Journals (Sweden)

Hairul Anwar

2016-02-01

Kata kunci: perangkat pembelajaran IPA, model 5E, penelitian pengembangan THE DEVELOPMENT OF 5E MODEL OF SCIENCE TEACHING KITS IN JUNIOR HIGH SCHOOL Abstract: The purpose of this study was to develop the 5E model science teaching kits in Junior High School 2 Kopang. This was a research and development study referring to Dick and Carey model. The formative evaluation stage wasdone by: (1 the validation of the kitsby 3 experts and 1 teacher as users, (2 the limited trial on the teaching kits (syllabus, lesson plan, and students’ worksheets held in grade VII, and (3 the validation of the assessment instrument (Science Process Skills/SPS test, Cognitive Achievement/CA test and Affective Achievement/AA questionnaires held in VIII. The average score of the validation result showed that all teaching kits were suitable to be used in the limited trial. The use of the teaching kits (syllabus and lesson plan in the limited trial obtainedpositive responses from the teacher of grade VII as the observer with an average score of 4.20 and “strongly-agree” responses from students with an average score 4.12. The students also showed strong agreement on the worksheets with an average score of 4.14. The result of the validity and reliability test on the instrument showed that all the items of the SPS test, those of the CA test, and those of the AA questionnaires were valid. The Cronbach’s alpha reliability coefficient was > 0.423. Keywords: science teachingkits, the 5E model, research and development

Advanced training simulator models. Implementation and validation

International Nuclear Information System (INIS)

Borkowsky, Jeffrey; Judd, Jerry; Belblidia, Lotfi; O'farrell, David; Andersen, Peter

2008-01-01

Modern training simulators are required to replicate plant data for both thermal-hydraulic and neutronic response. Replication is required such that reactivity manipulation on the simulator properly trains the operator for reactivity manipulation at the plant. This paper discusses advanced models which perform this function in real-time using the coupled code system THOR/S3R. This code system models the all fluids systems in detail using an advanced, two-phase thermal-hydraulic a model. The nuclear core is modeled using an advanced, three-dimensional nodal method and also by using cycle-specific nuclear data. These models are configured to run interactively from a graphical instructor station or handware operation panels. The simulator models are theoretically rigorous and are expected to replicate the physics of the plant. However, to verify replication, the models must be independently assessed. Plant data is the preferred validation method, but plant data is often not available for many important training scenarios. In the absence of data, validation may be obtained by slower-than-real-time transient analysis. This analysis can be performed by coupling a safety analysis code and a core design code. Such a coupling exists between the codes RELAP5 and SIMULATE-3K (S3K). RELAP5/S3K is used to validate the real-time model for several postulated plant events. (author)

MODEL PELATIHAN GURU ILMU PENGETAHUAN SOSIAL DI SMP MUHAMMADIYAH KARTASURA

Directory of Open Access Journals (Sweden)

Tjipto Subadi

2017-01-01

Full Text Available The study aimed to review and describe: 1 Coaching model of social sciences teacher in SMP Muhammadiyah Kartasura. 2 Test the validation of coaching model on social sciences teacher. This study used a qualitative approach of phenomenology. This study was conducted in SMP Muhammadiyah Kartasura, Sukoharjo district. The research design was classroom action research. The subject in this research were students, teachers, the principal. Data collection technique used observation, testing and interview. The interview process using theory of first and second order understanding. Data were analyzed using an interactive model included data reduction, data display, and conclusion. This study concluded that 1 Coaching Model of social sciences teacher in SMP Muhammadiyah Kartasura used modification lesson study approach. 2 Validation of the coaching model using two kinds of validation namely theory of validation and practice of validation.

Model Pembelajaran Seni Musik melalui Lesson Study: Studi Kasus di SDN Jawilan, Serang

Directory of Open Access Journals (Sweden)

Yulianti Fitriani

2015-03-01

Full Text Available Artikel ini dilatar-belakangi persoalan pembelajaran seni musik di SDN Jawilan Kab. Serang. Di SD ini penyelenggaraan pendidikan seni belum memperoleh perhatian yang cukup baik dari guru. Hal ini dapat dilihat dari pembagian alokasi waktu pembelajaran dan keterlibatan guru kelas yang tidak memiliki latar belakang pendidikan seni (musik. Dampak yang muncul, rata-rata siswa belum memiliki kemandirian dalam berkreativitas dan kurang berpartisipasi aktif dalam kegiatan musik baik di sekolah maupun di luar sekolah. Untuk memperbaiki persoalan tersebut dirasa perlu meminjam Lesson Study yang di dalamnya terdapat metode, pendekatan dan strategi pembelajaran sebagai pola untuk membelajarkan seni musik agar dapat memberikan alternatif sudut pandang terhadap persoalan metode yang tepat guna dan terencana dalam pengajaran pendidikan musik di SD, termasuk paradigma membelajarkan musik secara hakiki. Hasil yang diperoleh dapat memberikan alternatif sebagai dasar pengembangan pembelajaran seni musik.   The Model of Music Learning through a Lesson Study: A Case Study in Jawilan Elementary School, Serang. The learning problems of music lessons at Jawilan Elementary School in Serang becomes the mainly source of the research background in this article. The implementation of art education in this school has not gained enough attention from teachers. It can be seen from the distribution of the allocated time of learning and the involvement of classroom teachers who do not have sufficient background in art education (music. The appearing impact shows that the average of students do not have any independence in creativity and have less-active participation in the activities of musical arts either in school or outside the school. However, solving the problem is necessary to do by using a Lesson Study as a pattern (approaches, strategies, and methods of learning to teach music that can be used as an alternative point of view in developing methods and organizing the

Breathing Life into Engineering: A Lesson Study Life Science Lesson

Science.gov (United States)

Lawrence, Maria; Yang, Li-Ling; Briggs, May; Hession, Alicia; Koussa, Anita; Wagoner, Lisa

2016-01-01

A fifth grade life science lesson was implemented through a lesson study approach in two fifth grade classrooms. The research lesson was designed by a team of four elementary school teachers with the goal of emphasizing engineering practices consistent with the "Next Generation Science Standards" (NGSS) (Achieve Inc. 2013). The fifth…

World Hunger: Famine in Africa. Sample Lessons, Secondary.

Science.gov (United States)

Neeson, Eileen; And Others

This model social studies lesson includes a simulated interview with a relief worker describing the famine conditions in Ethiopia. A map of Africa and pictures of famine victims are included. The objectives of the lesson are to have students describe the situation in Ethiopia, analyze the causes, and evaluate solutions to the famine. In the model…

Lessons Learned From the Development and Parameterization of a Computer Simulation Model to Evaluate Task Modification for Health Care Providers.

Science.gov (United States)

Kasaie, Parastu; David Kelton, W; Ancona, Rachel M; Ward, Michael J; Froehle, Craig M; Lyons, Michael S

2018-02-01

Computer simulation is a highly advantageous method for understanding and improving health care operations with a wide variety of possible applications. Most computer simulation studies in emergency medicine have sought to improve allocation of resources to meet demand or to assess the impact of hospital and other system policies on emergency department (ED) throughput. These models have enabled essential discoveries that can be used to improve the general structure and functioning of EDs. Theoretically, computer simulation could also be used to examine the impact of adding or modifying specific provider tasks. Doing so involves a number of unique considerations, particularly in the complex environment of acute care settings. In this paper, we describe conceptual advances and lessons learned during the design, parameterization, and validation of a computer simulation model constructed to evaluate changes in ED provider activity. We illustrate these concepts using examples from a study focused on the operational effects of HIV screening implementation in the ED. Presentation of our experience should emphasize the potential for application of computer simulation to study changes in health care provider activity and facilitate the progress of future investigators in this field. © 2017 by the Society for Academic Emergency Medicine.

Brentwood Lessons Learned Project Report

Energy Technology Data Exchange (ETDEWEB)

Rivkin, Carl H. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Caton, Melanie C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ainscough, Christopher D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Marcinkoski, Jason [Dept. of Energy (DOE), Washington DC (United States)

2017-09-26

The purpose of this report is to document lessons learned in the installation of the hydrogen fueling station at the National Park Service Brentwood site in Washington, D.C., to help further the deployment of hydrogen infrastructure required to support hydrogen and other fuel cell technologies. Hydrogen fueling is the most difficult infrastructure component to build and permit. Hydrogen fueling can include augmenting hydrogen fueling capability to existing conventional fuel fueling stations as well as building brand new hydrogen fueling stations. This report was produced as part of the Brentwood Lessons Learned project. The project consisted of transplanting an existing modular hydrogen fueling station from Connecticut to the National Park Service Brentwood site. This relocation required design and construction at the Brentwood site to accommodate the existing station design as well as installation and validation of the updated station. One of the most important lessons learned was that simply moving an existing modular station to an operating site was not necessarily straight-forward - performing the relocation required significant effort and cost. The station has to function at the selected operating site and this functionality requires a power supply, building supports connecting to an existing alarm system, electrical grounding and lighting, providing nitrogen for purging, and providing deionized water if an electrolyzer is part of the station package. Most importantly, the station has to fit into the existing site both spatially and operationally and not disrupt existing operations at the site. All of this coordination and integration requires logistical planning and project management. The idea that a hydrogen fueling station can be simply dropped onto a site and made immediately operational is generally not realistic. Other important lessons learned include that delineating the boundaries of the multiple jurisdictions that have authority over a project for

Literacy Models and the Reconstruction of History Education: A Comparative Discourse Analysis of Two Lesson Plans

Science.gov (United States)

Collin, Ross; Reich, Gabriel A.

2015-01-01

This article presents discourse analyses of two lesson plans designed for secondary school history classes. Although the plans focus on the same topic, they rely on different models of content area literacy: disciplinary literacy, or reading and writing like experts in a given domain, and critical literacy, or reading and writing to address…

The Knitting Lesson.

Science.gov (United States)

Smith, Pamela

1987-01-01

Based on Jean-Francois Millet's 1869 painting, "The Knitting Lesson," this lesson's goal is to introduce students in grades seven through nine to genre (everyday life) painting the nineteenth century. The lesson is also designed to show that some aspects of genre may be timeless. (BSR)

Enhancing mathematics teachers' quality through Lesson Study.

Science.gov (United States)

Lomibao, Laila S

2016-01-01

The efficiency and effectivity of the learning experience is dependent on the teacher quality, thus, enhancing teacher's quality is vital in improving the students learning outcome. Since, the usual top-down one-shot cascading model practice for teachers' professional development in Philippines has been observed to have much information dilution, and the Southeast Asian Ministers of Education Organization demanded the need to develop mathematics teachers' quality standards through the Southeast Asia Regional Standards for Mathematics Teachers (SEARS-MT), thus, an intensive, ongoing professional development model should be provided to teachers. This study was undertaken to determine the impact of Lesson Study on Bulua National High School mathematics teachers' quality level in terms of SEARS-MT dimensions. A mixed method of quantitative-qualitative research design was employed. Results of the analysis revealed that Lesson Study effectively enhanced mathematics teachers' quality and promoted teachers professional development. Teachers positively perceived Lesson Study to be beneficial for them to become a better mathematics teacher.

Prospective validation of pathologic complete response models in rectal cancer: Transferability and reproducibility.

Science.gov (United States)

van Soest, Johan; Meldolesi, Elisa; van Stiphout, Ruud; Gatta, Roberto; Damiani, Andrea; Valentini, Vincenzo; Lambin, Philippe; Dekker, Andre

2017-09-01

Multiple models have been developed to predict pathologic complete response (pCR) in locally advanced rectal cancer patients. Unfortunately, validation of these models normally omit the implications of cohort differences on prediction model performance. In this work, we will perform a prospective validation of three pCR models, including information whether this validation will target transferability or reproducibility (cohort differences) of the given models. We applied a novel methodology, the cohort differences model, to predict whether a patient belongs to the training or to the validation cohort. If the cohort differences model performs well, it would suggest a large difference in cohort characteristics meaning we would validate the transferability of the model rather than reproducibility. We tested our method in a prospective validation of three existing models for pCR prediction in 154 patients. Our results showed a large difference between training and validation cohort for one of the three tested models [Area under the Receiver Operating Curve (AUC) cohort differences model: 0.85], signaling the validation leans towards transferability. Two out of three models had a lower AUC for validation (0.66 and 0.58), one model showed a higher AUC in the validation cohort (0.70). We have successfully applied a new methodology in the validation of three prediction models, which allows us to indicate if a validation targeted transferability (large differences between training/validation cohort) or reproducibility (small cohort differences). © 2017 American Association of Physicists in Medicine.

The key factors affecting students' individual interest in school science lessons

Science.gov (United States)

Cheung, Derek

2018-01-01

Individual interest in school science lessons can be defined as a relatively stable and enduring personal emotion comprising affective and behavioural reactions to events in the regular science lessons at school. Little research has compared the importance of different factors affecting students' individual interest in school science lessons. The present study aimed to address this gap, using a mixed methods design. Qualitative interview data were collected from 60 Hong Kong junior secondary school students, who were asked to describe the nature of their interest in science lessons and the factors to which they attribute this. Teacher interviews, parent interviews, and classroom observations were conducted to triangulate student interview data. Five factors affecting students' individual interest in school science lessons were identified: situational influences in science lessons, individual interest in science, science self-concept, grade level, and gender. Quantitative data were then collected from 591 students using a questionnaire. Structural equation modelling was applied to test a hypothesised model, which provided an acceptable fit to the student data. The strongest factor affecting students' individual interest in school science lessons was science self-concept, followed by individual interest in science and situational influences in science lessons. Grade level and gender were found to be nonsignificant factors. These findings suggest that teachers should pay special attention to the association between academic self-concept and interest if they want to motivate students to learn science at school.

A methodology for PSA model validation

International Nuclear Information System (INIS)

Unwin, S.D.

1995-09-01

This document reports Phase 2 of work undertaken by Science Applications International Corporation (SAIC) in support of the Atomic Energy Control Board's Probabilistic Safety Assessment (PSA) review. A methodology is presented for the systematic review and evaluation of a PSA model. These methods are intended to support consideration of the following question: To within the scope and depth of modeling resolution of a PSA study, is the resultant model a complete and accurate representation of the subject plant? This question was identified as a key PSA validation issue in SAIC's Phase 1 project. The validation methods are based on a model transformation process devised to enhance the transparency of the modeling assumptions. Through conversion to a 'success-oriented' framework, a closer correspondence to plant design and operational specifications is achieved. This can both enhance the scrutability of the model by plant personnel, and provide an alternative perspective on the model that may assist in the identification of deficiencies. The model transformation process is defined and applied to fault trees documented in the Darlington Probabilistic Safety Evaluation. A tentative real-time process is outlined for implementation and documentation of a PSA review based on the proposed methods. (author). 11 refs., 9 tabs., 30 refs

Assessing Discriminative Performance at External Validation of Clinical Prediction Models.

Directory of Open Access Journals (Sweden)

Daan Nieboer

Full Text Available External validation studies are essential to study the generalizability of prediction models. Recently a permutation test, focusing on discrimination as quantified by the c-statistic, was proposed to judge whether a prediction model is transportable to a new setting. We aimed to evaluate this test and compare it to previously proposed procedures to judge any changes in c-statistic from development to external validation setting.We compared the use of the permutation test to the use of benchmark values of the c-statistic following from a previously proposed framework to judge transportability of a prediction model. In a simulation study we developed a prediction model with logistic regression on a development set and validated them in the validation set. We concentrated on two scenarios: 1 the case-mix was more heterogeneous and predictor effects were weaker in the validation set compared to the development set, and 2 the case-mix was less heterogeneous in the validation set and predictor effects were identical in the validation and development set. Furthermore we illustrated the methods in a case study using 15 datasets of patients suffering from traumatic brain injury.The permutation test indicated that the validation and development set were homogenous in scenario 1 (in almost all simulated samples and heterogeneous in scenario 2 (in 17%-39% of simulated samples. Previously proposed benchmark values of the c-statistic and the standard deviation of the linear predictors correctly pointed at the more heterogeneous case-mix in scenario 1 and the less heterogeneous case-mix in scenario 2.The recently proposed permutation test may provide misleading results when externally validating prediction models in the presence of case-mix differences between the development and validation population. To correctly interpret the c-statistic found at external validation it is crucial to disentangle case-mix differences from incorrect regression coefficients.

The history of a lesson

DEFF Research Database (Denmark)

Rasmussen, Mikkel Vedby

2003-01-01

and emphasises the need to study the history of lessons rather than the lessons of history. This approach shows that Munich is the end point of a constitutive history that begins in the failure of the Versailles treaty to create a durable European order following the First World War. The Munich lesson is thus......The article investigates the concept of lessons in IR. By means of a constructivist critique of the 'lessons literature', the article analyses one of the most important of IR lessons: that of Munich. Examining how the Munich lesson came about, the article shows the praxeological nature of lessons...... one element of the lesson of Versailles, which is a praxeology that defines how the West is to make peace, and against whom peace must be defended. The lesson of Versailles has been, at least in part, constitutive of the outbreak of the Cold War, and it continues to define the Western conception...

Validation and comparison of dispersion models of RTARC DSS

International Nuclear Information System (INIS)

Duran, J.; Pospisil, M.

2004-01-01

RTARC DSS (Real Time Accident Release Consequences - Decision Support System) is a computer code developed at the VUJE Trnava, Inc. (Stubna, M. et al, 1993). The code calculations include atmospheric transport and diffusion, dose assessment, evaluation and displaying of the affected zones, evaluation of the early health effects, concentration and dose rate time dependence in the selected sites etc. The simulation of the protective measures (sheltering, iodine administration) is involved. The aim of this paper is to present the process of validation of the RTARC dispersion models. RTARC includes models for calculations of release for very short (Method Monte Carlo - MEMOC), short (Gaussian Straight-Line Model) and long distances (Puff Trajectory Model - PTM). Validation of the code RTARC was performed using the results of comparisons and experiments summarized in the Table 1.: 1. Experiments and comparisons in the process of validation of the system RTARC - experiments or comparison - distance - model. Wind tunnel experiments (Universitaet der Bundeswehr, Muenchen) - Area of NPP - Method Monte Carlo. INEL (Idaho National Engineering Laboratory) - short/medium - Gaussian model and multi tracer atmospheric experiment - distances - PTM. Model Validation Kit - short distances - Gaussian model. STEP II.b 'Realistic Case Studies' - long distances - PTM. ENSEMBLE comparison - long distances - PTM (orig.)

Cross-validation pitfalls when selecting and assessing regression and classification models.

Science.gov (United States)

Krstajic, Damjan; Buturovic, Ljubomir J; Leahy, David E; Thomas, Simon

2014-03-29

We address the problem of selecting and assessing classification and regression models using cross-validation. Current state-of-the-art methods can yield models with high variance, rendering them unsuitable for a number of practical applications including QSAR. In this paper we describe and evaluate best practices which improve reliability and increase confidence in selected models. A key operational component of the proposed methods is cloud computing which enables routine use of previously infeasible approaches. We describe in detail an algorithm for repeated grid-search V-fold cross-validation for parameter tuning in classification and regression, and we define a repeated nested cross-validation algorithm for model assessment. As regards variable selection and parameter tuning we define two algorithms (repeated grid-search cross-validation and double cross-validation), and provide arguments for using the repeated grid-search in the general case. We show results of our algorithms on seven QSAR datasets. The variation of the prediction performance, which is the result of choosing different splits of the dataset in V-fold cross-validation, needs to be taken into account when selecting and assessing classification and regression models. We demonstrate the importance of repeating cross-validation when selecting an optimal model, as well as the importance of repeating nested cross-validation when assessing a prediction error.

Lesson Learning at JPL

Science.gov (United States)

Oberhettinger, David

2011-01-01

A lessons learned system is a hallmark of a mature engineering organization A formal lessons learned process can help assure that valuable lessons get written and published, that they are well-written, and that the essential information is "infused" into institutional practice. Requires high-level institutional commitment, and everyone's participation in gathering, disseminating, and using the lessons

Developing a model for validation and prediction of bank customer ...

African Journals Online (AJOL)

Credit risk is the most important risk of banks. The main approaches of the bank to reduce credit risk are correct validation using the final status and the validation model parameters. High fuel of bank reserves and lost or outstanding facilities of banks indicate the lack of appropriate validation models in the banking network.

Validation of heat transfer models for gap cooling

International Nuclear Information System (INIS)

Okano, Yukimitsu; Nagae, Takashi; Murase, Michio

2004-01-01

For severe accident assessment of a light water reactor, models of heat transfer in a narrow annular gap between overheated core debris and a reactor pressure vessel are important for evaluating vessel integrity and accident management. The authors developed and improved the models of heat transfer. However, validation was not sufficient for applicability of the gap heat flux correlation to the debris cooling in the vessel lower head and applicability of the local boiling heat flux correlations to the high-pressure conditions. Therefore, in this paper, we evaluated the validity of the heat transfer models and correlations by analyses for ALPHA and LAVA experiments where molten aluminum oxide (Al 2 O 3 ) at about 2700 K was poured into the high pressure water pool in a small-scale simulated vessel lower head. In the heating process of the vessel wall, the calculated heating rate and peak temperature agreed well with the measured values, and the validity of the heat transfer models and gap heat flux correlation was confirmed. In the cooling process of the vessel wall, the calculated cooling rate was compared with the measured value, and the validity of the nucleate boiling heat flux correlation was confirmed. The peak temperatures of the vessel wall in ALPHA and LAVA experiments were lower than the temperature at the minimum heat flux point between film boiling and transition boiling, so the minimum heat flux correlation could not be validated. (author)

Solar Sail Models and Test Measurements Correspondence for Validation Requirements Definition

Science.gov (United States)

Ewing, Anthony; Adams, Charles

2004-01-01

Solar sails are being developed as a mission-enabling technology in support of future NASA science missions. Current efforts have advanced solar sail technology sufficient to justify a flight validation program. A primary objective of this activity is to test and validate solar sail models that are currently under development so that they may be used with confidence in future science mission development (e.g., scalable to larger sails). Both system and model validation requirements must be defined early in the program to guide design cycles and to ensure that relevant and sufficient test data will be obtained to conduct model validation to the level required. A process of model identification, model input/output documentation, model sensitivity analyses, and test measurement correspondence is required so that decisions can be made to satisfy validation requirements within program constraints.

The Construction of Biology Lessons: A Meta-Paradigmatic Approach.

Science.gov (United States)

Sanchez, Jaime

1991-01-01

The views of Piaget, Ausubel, and Bruner have been used to present an integrated view of biology lesson construction and to assist teachers in the design and development of tools and strategies to improve their teaching. The structure of an integrated model for biology lesson construction and an example of a biolesson using the metaparadigmatic…

Integrating UNESCO ICT-Based Instructional Materials in Chemistry Lessons

Directory of Open Access Journals (Sweden)

CHARLIE P. NACARIO

2014-08-01

Full Text Available This study determined the effectiveness of the lessons in Chemistry integrating UNESCO ICT-based instructional material on the achievement of Chemistry students at Central Bicol State University of Agriculture. It aimed to identify lessons that may be developed integrating UNESCO ICT-based instructional materials, determine the effect of the developed lessons using the material on: conceptual understanding; science process skills; and attitude towards chemistry and gather insights from the experiences of the students and teacher. The study used the single group pretest and posttest experimental design. Descriptive, quantitative and qualitative techniques were also utilized. Quantitative data were taken from the pretest-posttest results on the Test on Conceptual Understanding, Science Process Skills and Chemistry Attitudinaire. Qualitative data were drawn from the experts’ assessment of the developed lessons and research instruments, and the insights of students and teacher. The developed lessons integrating UNESCO ICT-based instructional materials were Atomic Model and Structure, Periodic Table of Elements, Chemical Bonding, and Balancing Chemical Equation. These lessons increased the conceptual understanding of the students by topic and skill from very low mastery to average mastery level. The students have slightly improved along the different science process skills. After teaching the lessons, the students’ attitude also improved. The students became more motivated and interested in Chemistry and the lessons were student centered and entailed teacher’s competence and flexibility in computer use.

An approach to model validation and model-based prediction -- polyurethane foam case study.

Energy Technology Data Exchange (ETDEWEB)

Dowding, Kevin J.; Rutherford, Brian Milne

2003-07-01

Enhanced software methodology and improved computing hardware have advanced the state of simulation technology to a point where large physics-based codes can be a major contributor in many systems analyses. This shift toward the use of computational methods has brought with it new research challenges in a number of areas including characterization of uncertainty, model validation, and the analysis of computer output. It is these challenges that have motivated the work described in this report. Approaches to and methods for model validation and (model-based) prediction have been developed recently in the engineering, mathematics and statistical literatures. In this report we have provided a fairly detailed account of one approach to model validation and prediction applied to an analysis investigating thermal decomposition of polyurethane foam. A model simulates the evolution of the foam in a high temperature environment as it transforms from a solid to a gas phase. The available modeling and experimental results serve as data for a case study focusing our model validation and prediction developmental efforts on this specific thermal application. We discuss several elements of the ''philosophy'' behind the validation and prediction approach: (1) We view the validation process as an activity applying to the use of a specific computational model for a specific application. We do acknowledge, however, that an important part of the overall development of a computational simulation initiative is the feedback provided to model developers and analysts associated with the application. (2) We utilize information obtained for the calibration of model parameters to estimate the parameters and quantify uncertainty in the estimates. We rely, however, on validation data (or data from similar analyses) to measure the variability that contributes to the uncertainty in predictions for specific systems or units (unit-to-unit variability). (3) We perform statistical

Mathematics Teachers' Views of Accountability Testing Revealed through Lesson Study

Science.gov (United States)

Yarema, Connie H.

2010-01-01

The practice of lesson study, a professional development model originating in Japan, aligns well with recommendations from research for teacher professional development. Lesson study is also an inductive research method that uncovers student thinking and, in parallel, grants teacher-educators the opportunity to study teachers' thinking about…

Experimental Validation of Flow Force Models for Fast Switching Valves

DEFF Research Database (Denmark)

Bender, Niels Christian; Pedersen, Henrik Clemmensen; Nørgård, Christian

2017-01-01

This paper comprises a detailed study of the forces acting on a Fast Switching Valve (FSV) plunger. The objective is to investigate to what extend different models are valid to be used for design purposes. These models depend on the geometry of the moving plunger and the properties of the surroun......This paper comprises a detailed study of the forces acting on a Fast Switching Valve (FSV) plunger. The objective is to investigate to what extend different models are valid to be used for design purposes. These models depend on the geometry of the moving plunger and the properties...... to compare and validate different models, where an effort is directed towards capturing the fluid squeeze effect just before material on material contact. The test data is compared with simulation data relying solely on analytic formulations. The general dynamics of the plunger is validated...

Statistical validation of normal tissue complication probability models

NARCIS (Netherlands)

Xu, Cheng-Jian; van der Schaaf, Arjen; van t Veld, Aart; Langendijk, Johannes A.; Schilstra, Cornelis

2012-01-01

PURPOSE: To investigate the applicability and value of double cross-validation and permutation tests as established statistical approaches in the validation of normal tissue complication probability (NTCP) models. METHODS AND MATERIALS: A penalized regression method, LASSO (least absolute shrinkage

Preliminary validation of a Monte Carlo model for IMRT fields

International Nuclear Information System (INIS)

Wright, Tracy; Lye, Jessica; Mohammadi, Mohammad

2011-01-01

Full text: A Monte Carlo model of an Elekta linac, validated for medium to large (10-30 cm) symmetric fields, has been investigated for small, irregular and asymmetric fields suitable for IMRT treatments. The model has been validated with field segments using radiochromic film in solid water. The modelled positions of the multileaf collimator (MLC) leaves have been validated using EBT film, In the model, electrons with a narrow energy spectrum are incident on the target and all components of the linac head are included. The MLC is modelled using the EGSnrc MLCE component module. For the validation, a number of single complex IMRT segments with dimensions approximately 1-8 cm were delivered to film in solid water (see Fig, I), The same segments were modelled using EGSnrc by adjusting the MLC leaf positions in the model validated for 10 cm symmetric fields. Dose distributions along the centre of each MLC leaf as determined by both methods were compared. A picket fence test was also performed to confirm the MLC leaf positions. 95% of the points in the modelled dose distribution along the leaf axis agree with the film measurement to within 1%/1 mm for dose difference and distance to agreement. Areas of most deviation occur in the penumbra region. A system has been developed to calculate the MLC leaf positions in the model for any planned field size.

Using a Before-During-After (BDA) Model to Plan Effective Secondary Mathematics Lessons

Science.gov (United States)

Wilburne, Jane Murphy; Peterson, Winnie

2007-01-01

Creating effective mathematics lessons can be a challenge for any teacher. One approach to design an effective lesson is using a before-during-after (BDA) format. This article describes what a BDA format is and provides two examples of how it is implemented in high school mathematics classes. (Contains 2 tables and 5 figures.)

Validation techniques of agent based modelling for geospatial simulations

Directory of Open Access Journals (Sweden)

M. Darvishi

2014-10-01

Full Text Available One of the most interesting aspects of modelling and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a model in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based modelling and simulation (ABMS is a new modelling method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS, biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI’s ArcGIS, OpenMap, GeoTools, etc for geospatial modelling is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their validation and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to validate and verify ABMS by conventional validation methods. Therefore, attempt to find appropriate validation techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the validation techniques and challenges of ABM validation are discussed.

Validation techniques of agent based modelling for geospatial simulations

Science.gov (United States)

Darvishi, M.; Ahmadi, G.

2014-10-01

One of the most interesting aspects of modelling and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a model in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based modelling and simulation (ABMS) is a new modelling method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS), biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI's ArcGIS, OpenMap, GeoTools, etc) for geospatial modelling is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their validation and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to validate and verify ABMS by conventional validation methods. Therefore, attempt to find appropriate validation techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the validation techniques and challenges of ABM validation are discussed.

BIOMOVS: an international model validation study

International Nuclear Information System (INIS)

Haegg, C.; Johansson, G.

1988-01-01

BIOMOVS (BIOspheric MOdel Validation Study) is an international study where models used for describing the distribution of radioactive and nonradioactive trace substances in terrestrial and aquatic environments are compared and tested. The main objectives of the study are to compare and test the accuracy of predictions between such models, explain differences in these predictions, recommend priorities for future research concerning the improvement of the accuracy of model predictions and act as a forum for the exchange of ideas, experience and information. (author)

BIOMOVS: An international model validation study

International Nuclear Information System (INIS)

Haegg, C.; Johansson, G.

1987-01-01

BIOMOVS (BIOspheric MOdel Validation Study) is an international study where models used for describing the distribution of radioactive and nonradioactive trace substances in terrestrial and aquatic environments are compared and tested. The main objectives of the study are to compare and test the accuracy of predictions between such models, explain differences in these predictions, recommend priorities for future research concerning the improvement of the accuracy of model predictions and act as a forum for the exchange of ideas, experience and information. (orig.)

A Practical Approach to Validating a PD Model

NARCIS (Netherlands)

Medema, L.; Koning, de R.; Lensink, B.W.

2009-01-01

The capital adequacy framework Basel II aims to promote the adoption of stronger risk management practices by the banking industry. The implementation makes validation of credit risk models more important. Lenders therefore need a validation methodology to convince their supervisors that their

A practical approach to validating a PD model

NARCIS (Netherlands)

Medema, Lydian; Koning, Ruud H.; Lensink, Robert; Medema, M.

The capital adequacy framework Basel II aims to promote the adoption of stronger risk management practices by the banking industry. The implementation makes validation of credit risk models more important. Lenders therefore need a validation methodology to convince their supervisors that their

Base Flow Model Validation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The innovation is the systematic "building-block" validation of CFD/turbulence models employing a GUI driven CFD code (RPFM) and existing as well as new data sets to...

Interactions between Preservice and Cooperating Teachers and Knowledge Construction during Post-Lesson Interviews

Science.gov (United States)

Chalies, S.; Ria, L.; Bertone, S.; Trohel, J.; Durand, M.

2004-01-01

This study analysed the relationships between (a) the nature of the interactions between preservice teachers and their cooperating teachers and (b) the knowledge that the teachers constructed, validated or invalidated during post-lesson interviews. Six interview excerpts, chosen as having been particularly instructive, were analysed from the…

Building Accessible Educational Web Sites: The Law, Standards, Guidelines, Tools, and Lessons Learned

Science.gov (United States)

Liu, Ye; Palmer, Bart; Recker, Mimi

2004-01-01

Professional education is increasingly facing accessibility challenges with the emergence of webbased learning. This paper summarizes related U.S. legislation, standards, guidelines, and validation tools to make web-based learning accessible for all potential learners. We also present lessons learned during the implementation of web accessibility…

Validation of the Physician Teaching Motivation Questionnaire (PTMQ).

Science.gov (United States)

Dybowski, Christoph; Harendza, Sigrid

2015-10-02

Physicians play a major role as teachers in undergraduate medical education. Studies indicate that different forms and degrees of motivation can influence work performance in general and that teachers' motivation to teach can influence students' academic achievements in particular. Therefore, the aim of this study was to develop and to validate an instrument measuring teaching motivations in hospital-based physicians. We chose self-determination theory as a theoretical framework for item and scale development. It distinguishes between different dimensions of motivation depending on the amount of self-regulation and autonomy involved and its empirical evidence has been demonstrated in other areas of research. To validate the new instrument (PTMQ = Physician Teaching Motivation Questionnaire), we used data from a sample of 247 physicians from internal medicine and surgery at six German medical faculties. Structural equation modelling was conducted to confirm the factorial structure, correlation analyses and linear regressions were performed to examine concurrent and incremental validity. Structural equation modelling confirmed a good global fit for the factorial structure of the final instrument (RMSEA = .050, TLI = .957, SRMR = .055, CFI = .966). Cronbach's alphas indicated good internal consistencies for all scales (α = .75 - .89) except for the identified teaching motivation subscale with an acceptable internal consistency (α = .65). Tests of concurrent validity with global work motivation, perceived teaching competence, perceived teaching involvement and voluntariness of lesson allocation delivered theory-consistent results with slight deviations for some scales. Incremental validity over global work motivation in predicting perceived teaching involvement was also confirmed. Our results indicate that the PTMQ is a reliable, valid and therefore suitable instrument for assessing physicians' teaching motivation.

The turbulent viscosity models and their experimental validation; Les modeles de viscosite turbulente et leur validation experimentale

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

This workshop on turbulent viscosity models and on their experimental validation was organized by the `convection` section of the French society of thermal engineers. From the 9 papers presented during this workshop, 8 deal with the modeling of turbulent flows inside combustion chambers, turbo-machineries or in other energy-related applications, and have been selected for ETDE. (J.S.)

Development of short Indonesian lesson plan to improve teacher performance

Science.gov (United States)

Yulianto, B.; Kamidjan; Ahmadi, A.; Asteria, P. V.

2018-01-01

The developmental research was motivated by the results of preliminary study through interviews, which revealed almost all of the teachers did not create lesson plan themselves. As a result of this load, the performance of the real learning in the classroom becomes inadequate. Moreover, when lesson plan was not made by teachers themselves, the learning process becomes ineffective. Therefore, this study designed to develop a prototype of the short lesson plan, in particular, Indonesian language teaching, and to investigate its effectiveness. The participants in the study were teachers who were trained through lesson study group to design short model’s lesson plan. Questionnaires and open-ended questions were used, and the quantitative and qualitative data obtained were analyzed accordingly. The analysis of the quantitative data, aided with SPSS, were frequency, percentage, and means, whereas the qualitative data were analyzed descriptively. The results showed that the teachers liked the model, and they were willing to design their own lesson plan. The observation data revealed that the classroom learning process became more interactive, and classroom atmosphere was more engaging and natural because the teachers did not stick to the lesson plan made by other teachers.

Lessons from patents. Using patents to measure technological change in environmental models

International Nuclear Information System (INIS)

Popp, David

2005-01-01

When studying solutions to long-term environmental problems such as climate change, it is important to consider the role that technological change may play. Nonetheless, to date few economic models of environmental policy explicitly model the link between policy and technological change. There is a growing body of evidence that the incentives offered by prices and environmental regulations have a strong influence on both the creation and adoption of new technologies. In several recent papers, I have used patent data to examine the links between environmental policy and technological change. In addition, I have used the results of this research to calibrate the ENTICE model (for ENdogenous Technological change) of climate change, which links energy-related R and D to changes in the price of carbon. Drawing on my experiences from empirical studies on innovation and from modeling the climate change problem, in this paper I review some of the key lessons from recent empirical work using patents to study environmental innovation and diffusion, and discuss its implications for modeling climate change policy. I conclude by offering suggestions for future research

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.

What Are the Effects of Science Lesson Planning in Peers?—Analysis of Attitudes and Knowledge Based on an Actor-Partner Interdependence Model

Science.gov (United States)

Smit, Robbert; Rietz, Florian; Kreis, Annelies

2018-06-01

This study focuses on the effects of collaborative lesson planning by science pre-service teachers on their attitudes and knowledge. In our study, 120 pre-service teachers discussed a preparation for a science inquiry lesson in dyads. The teacher with the lesson preparation had the role of the coachee, while the other was the coach. We investigated the following research questions: (1) Does learning occur between the two peers? and (2) Is the competency in lesson planning affected by the attitude and knowledge of coach and coachee? Based on an actor-partner interdependence model (APIM), we could clarify the relations of pedagogical content knowledge (PCK) and attitudes (ATT) between and within the dyads of coach and coachee, as well as their development over time. Furthermore, the APIM allowed the inclusion of a mediator (lesson planning competency). Both PCK and ATT increased slightly but significantly during our project. ATT and PCK seemed to converge between coach and coachee at the end of the project. However, we could not find any cross-lagged effects, meaning there was no effect of coach on coachee or vice versa over time. Further, preceding PCK showed a significant effect on the competency of lesson planning, but planning competency did not influence succeeding PCK or attitude. Finally, these results are discussed with respect to science teacher education.

What Are the Effects of Science Lesson Planning in Peers?—Analysis of Attitudes and Knowledge Based on an Actor-Partner Interdependence Model

Science.gov (United States)

Smit, Robbert; Rietz, Florian; Kreis, Annelies

2017-04-01

This study focuses on the effects of collaborative lesson planning by science pre-service teachers on their attitudes and knowledge. In our study, 120 pre-service teachers discussed a preparation for a science inquiry lesson in dyads. The teacher with the lesson preparation had the role of the coachee, while the other was the coach. We investigated the following research questions: (1) Does learning occur between the two peers? and (2) Is the competency in lesson planning affected by the attitude and knowledge of coach and coachee? Based on an actor-partner interdependence model (APIM), we could clarify the relations of pedagogical content knowledge (PCK) and attitudes (ATT) between and within the dyads of coach and coachee, as well as their development over time. Furthermore, the APIM allowed the inclusion of a mediator (lesson planning competency). Both PCK and ATT increased slightly but significantly during our project. ATT and PCK seemed to converge between coach and coachee at the end of the project. However, we could not find any cross-lagged effects, meaning there was no effect of coach on coachee or vice versa over time. Further, preceding PCK showed a significant effect on the competency of lesson planning, but planning competency did not influence succeeding PCK or attitude. Finally, these results are discussed with respect to science teacher education.

Concepts of Model Verification and Validation

International Nuclear Information System (INIS)

Thacker, B.H.; Doebling, S.W.; Hemez, F.M.; Anderson, M.C.; Pepin, J.E.; Rodriguez, E.A.

2004-01-01

Model verification and validation (VandV) is an enabling methodology for the development of computational models that can be used to make engineering predictions with quantified confidence. Model VandV procedures are needed by government and industry to reduce the time, cost, and risk associated with full-scale testing of products, materials, and weapon systems. Quantifying the confidence and predictive accuracy of model calculations provides the decision-maker with the information necessary for making high-consequence decisions. The development of guidelines and procedures for conducting a model VandV program are currently being defined by a broad spectrum of researchers. This report reviews the concepts involved in such a program. Model VandV is a current topic of great interest to both government and industry. In response to a ban on the production of new strategic weapons and nuclear testing, the Department of Energy (DOE) initiated the Science-Based Stockpile Stewardship Program (SSP). An objective of the SSP is to maintain a high level of confidence in the safety, reliability, and performance of the existing nuclear weapons stockpile in the absence of nuclear testing. This objective has challenged the national laboratories to develop high-confidence tools and methods that can be used to provide credible models needed for stockpile certification via numerical simulation. There has been a significant increase in activity recently to define VandV methods and procedures. The U.S. Department of Defense (DoD) Modeling and Simulation Office (DMSO) is working to develop fundamental concepts and terminology for VandV applied to high-level systems such as ballistic missile defense and battle management simulations. The American Society of Mechanical Engineers (ASME) has recently formed a Standards Committee for the development of VandV procedures for computational solid mechanics models. The Defense Nuclear Facilities Safety Board (DNFSB) has been a proponent of model

Verification and validation of models

International Nuclear Information System (INIS)

Herbert, A.W.; Hodgkinson, D.P.; Jackson, C.P.; Lever, D.A.; Robinson, P.C.

1986-12-01

The numerical accuracy of the computer models for groundwater flow and radionuclide transport that are to be used in repository safety assessment must be tested, and their ability to describe experimental data assessed: they must be verified and validated respectively. Also appropriate ways to use the codes in performance assessments, taking into account uncertainties in present data and future conditions, must be studied. These objectives are being met by participation in international exercises, by developing bench-mark problems, and by analysing experiments. In particular the project has funded participation in the HYDROCOIN project for groundwater flow models, the Natural Analogues Working Group, and the INTRAVAL project for geosphere models. (author)

Refinement, Validation and Benchmarking of a Model for E-Government Service Quality

Science.gov (United States)

Magoutas, Babis; Mentzas, Gregoris

This paper presents the refinement and validation of a model for Quality of e-Government Services (QeGS). We built upon our previous work where a conceptualized model was identified and put focus on the confirmatory phase of the model development process, in order to come up with a valid and reliable QeGS model. The validated model, which was benchmarked with very positive results with similar models found in the literature, can be used for measuring the QeGS in a reliable and valid manner. This will form the basis for a continuous quality improvement process, unleashing the full potential of e-government services for both citizens and public administrations.

Geochemistry Model Validation Report: Material Degradation and Release Model

Energy Technology Data Exchange (ETDEWEB)

H. Stockman

2001-09-28

The purpose of this Analysis and Modeling Report (AMR) is to validate the Material Degradation and Release (MDR) model that predicts degradation and release of radionuclides from a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. This AMR is prepared according to ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 17). The intended use of the MDR model is to estimate the long-term geochemical behavior of waste packages (WPs) containing U. S . Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The model is intended to predict (1) the extent to which criticality control material, such as gadolinium (Gd), will remain in the WP after corrosion of the initial WP, (2) the extent to which fissile Pu and uranium (U) will be carried out of the degraded WP by infiltrating water, and (3) the chemical composition and amounts of minerals and other solids left in the WP. The results of the model are intended for use in criticality calculations. The scope of the model validation report is to (1) describe the MDR model, and (2) compare the modeling results with experimental studies. A test case based on a degrading Pu-ceramic WP is provided to help explain the model. This model does not directly feed the assessment of system performance. The output from this model is used by several other models, such as the configuration generator, criticality, and criticality consequence models, prior to the evaluation of system performance. This document has been prepared according to AP-3.10Q, ''Analyses and Models'' (Ref. 2), and prepared in accordance with the technical work plan (Ref. 17).

Geochemistry Model Validation Report: Material Degradation and Release Model

International Nuclear Information System (INIS)

Stockman, H.

2001-01-01

The purpose of this Analysis and Modeling Report (AMR) is to validate the Material Degradation and Release (MDR) model that predicts degradation and release of radionuclides from a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. This AMR is prepared according to ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 17). The intended use of the MDR model is to estimate the long-term geochemical behavior of waste packages (WPs) containing U. S . Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The model is intended to predict (1) the extent to which criticality control material, such as gadolinium (Gd), will remain in the WP after corrosion of the initial WP, (2) the extent to which fissile Pu and uranium (U) will be carried out of the degraded WP by infiltrating water, and (3) the chemical composition and amounts of minerals and other solids left in the WP. The results of the model are intended for use in criticality calculations. The scope of the model validation report is to (1) describe the MDR model, and (2) compare the modeling results with experimental studies. A test case based on a degrading Pu-ceramic WP is provided to help explain the model. This model does not directly feed the assessment of system performance. The output from this model is used by several other models, such as the configuration generator, criticality, and criticality consequence models, prior to the evaluation of system performance. This document has been prepared according to AP-3.10Q, ''Analyses and Models'' (Ref. 2), and prepared in accordance with the technical work plan (Ref. 17)

SPR Hydrostatic Column Model Verification and Validation.

Energy Technology Data Exchange (ETDEWEB)

Bettin, Giorgia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rudeen, David Keith [Gram, Inc. Albuquerque, NM (United States)

2015-10-01

A Hydrostatic Column Model (HCM) was developed to help differentiate between normal "tight" well behavior and small-leak behavior under nitrogen for testing the pressure integrity of crude oil storage wells at the U.S. Strategic Petroleum Reserve. This effort was motivated by steady, yet distinct, pressure behavior of a series of Big Hill caverns that have been placed under nitrogen for extended period of time. This report describes the HCM model, its functional requirements, the model structure and the verification and validation process. Different modes of operation are also described, which illustrate how the software can be used to model extended nitrogen monitoring and Mechanical Integrity Tests by predicting wellhead pressures along with nitrogen interface movements. Model verification has shown that the program runs correctly and it is implemented as intended. The cavern BH101 long term nitrogen test was used to validate the model which showed very good agreement with measured data. This supports the claim that the model is, in fact, capturing the relevant physical phenomena and can be used to make accurate predictions of both wellhead pressure and interface movements.

Lessons learned from case studies of inhalation exposures of workers to radioactive aerosols

Energy Technology Data Exchange (ETDEWEB)

Hoover, M.D.; Fencl, A.F.; Newton, G.J. [and others

1995-12-01

Various Department of Energy requirements, rules, and orders mandate that lessons learned be identified, evaluated, shared, and incorporated into current practices. The recently issued, nonmandatory DOE standard for Development of DOE Lessons Learned Program states that a DOE-wide lessons learned program will {open_quotes}help to prevent recurrences of negative experiences, highlight best practices, and spotlight innovative ways to solve problems or perform work more safely, efficiently, and cost effectively.{close_quotes} Additional information about the lessons learned program is contained in the recently issued DOE handbook on Implementing U.S. Department of Energy Lessons Learned Programs and in October 1995 DOE SAfety Notice on Lessons Learned Programs. This report summarizes work in progress at ITRI to identify lessons learned for worker exposures to radioactive aerosols, and describes how this work will be incorporated into the DOE lessons learned program, including a new technical guide for measuring, modeling, and mitigating airborne radioactive particles. Follow-on work is focusing on preparation of {open_quotes}lessons learned{close_quotes} training materials for facility designers, managers, health protection professionals, line supervisors, and workers.

Lessons learned from case studies of inhalation exposures of workers to radioactive aerosols

International Nuclear Information System (INIS)

Hoover, M.D.; Fencl, A.F.; Newton, G.J.

1995-01-01

Various Department of Energy requirements, rules, and orders mandate that lessons learned be identified, evaluated, shared, and incorporated into current practices. The recently issued, nonmandatory DOE standard for Development of DOE Lessons Learned Program states that a DOE-wide lessons learned program will open-quotes help to prevent recurrences of negative experiences, highlight best practices, and spotlight innovative ways to solve problems or perform work more safely, efficiently, and cost effectively.close quotes Additional information about the lessons learned program is contained in the recently issued DOE handbook on Implementing U.S. Department of Energy Lessons Learned Programs and in October 1995 DOE SAfety Notice on Lessons Learned Programs. This report summarizes work in progress at ITRI to identify lessons learned for worker exposures to radioactive aerosols, and describes how this work will be incorporated into the DOE lessons learned program, including a new technical guide for measuring, modeling, and mitigating airborne radioactive particles. Follow-on work is focusing on preparation of open-quotes lessons learnedclose quotes training materials for facility designers, managers, health protection professionals, line supervisors, and workers

Dragons and Dinosaurs: Directing Inquiry in Biology Using the Notions of "Milieu" and "Validation"

Science.gov (United States)

Achiam, Marianne; Solberg, Jan; Evans, Robert

2013-01-01

This article describes how inquiry teaching can be directed towards specific content learning goals while allowing for student exploration and validation of hypotheses. Drawing from the Theory of Didactical Situations, the concepts of "milieu" and "validation" are illustrated through two sample biology lessons designed to engage and challenge…

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.

Geochemistry Model Validation Report: External Accumulation Model

International Nuclear Information System (INIS)

Zarrabi, K.

2001-01-01

The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

IN-DRIFT MICROBIAL COMMUNITIES MODEL VALIDATION CALCULATIONS

Energy Technology Data Exchange (ETDEWEB)

D.M. Jolley

2001-12-18

The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN M09909SPAMINGl.003 using its replacement DTN M00106SPAIDMO 1.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 200 1) which includes controls for the management of electronic data.

In-Drift Microbial Communities Model Validation Calculations

Energy Technology Data Exchange (ETDEWEB)

D. M. Jolley

2001-09-24

The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data.

In-Drift Microbial Communities Model Validation Calculation

Energy Technology Data Exchange (ETDEWEB)

D. M. Jolley

2001-10-31

The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data.

In-Drift Microbial Communities Model Validation Calculations

International Nuclear Information System (INIS)

Jolley, D.M.

2001-01-01

The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS MandO 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS MandO 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS MandO 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS MandO (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data

IN-DRIFT MICROBIAL COMMUNITIES MODEL VALIDATION CALCULATIONS

International Nuclear Information System (INIS)

D.M. Jolley

2001-01-01

The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M andO 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M andO 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN M09909SPAMINGl.003 using its replacement DTN M00106SPAIDMO 1.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M andO 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M andO (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 200 1) which includes controls for the management of electronic data

Validation of Computer Models for Homeland Security Purposes

International Nuclear Information System (INIS)

Schweppe, John E.; Ely, James; Kouzes, Richard T.; McConn, Ronald J.; Pagh, Richard T.; Robinson, Sean M.; Siciliano, Edward R.; Borgardt, James D.; Bender, Sarah E.; Earnhart, Alison H.

2005-01-01

At Pacific Northwest National Laboratory, we are developing computer models of radiation portal monitors for screening vehicles and cargo. Detailed models of the radiation detection equipment, vehicles, cargo containers, cargos, and radioactive sources have been created. These are used to determine the optimal configuration of detectors and the best alarm algorithms for the detection of items of interest while minimizing nuisance alarms due to the presence of legitimate radioactive material in the commerce stream. Most of the modeling is done with the Monte Carlo code MCNP to describe the transport of gammas and neutrons from extended sources through large, irregularly shaped absorbers to large detectors. A fundamental prerequisite is the validation of the computational models against field measurements. We describe the first step of this validation process, the comparison of the models to measurements with bare static sources

UNLEARNED LESSONS OF CONTEMPORARY HISTORY

Directory of Open Access Journals (Sweden)

А Н Данилов

2017-12-01

Full Text Available The article considers the complex geopolitical situation in the global world at the end of the second decade of the 21st century as determined by the consequences of the collapse of the Soviet Union and by the new world order. The author seeks to answer the questions who will define the current geopolitical situation, whose aims it will reflect, what will become the basis of new geopolitical realities, the basis of moral solidarity of humankind, and the spiritual basis of future civilizations. The new challenges give rise to a desperate struggle for different scenarios for building a happy life. Moreover, it is not clear which ideal of the future world will be widely supported as a development guideline. The recognition as such of the standard of living and development of the strongest ones becomes a real threat to the new civilization for it leads to the loss of national interests of sovereign states, and to the loss of an independent future. Today, there is an active search for new theories and concepts that will adequately explain con-temporary global processes. In this thematic context, the author identifies main lessons not learned by the world political elites. The first lesson: new states are not born in an empty place, their common history is a great advantage ensuring prospects for the further development of interstate cooperation. The second lesson: the widespread falsification of history has a negative impact on national, cultural and social-group identity in transforming societies. The third lesson: after the collapse of the Soviet Union, the post-war balance of power was destroyed together with the system of checks and balances in world politics (a bipolar model of the world. The fourth lesson: under radical social transformations, the moral system of the population devaluates with numerous crisis consequences.

Models, validation, and applied geochemistry: Issues in science, communication, and philosophy

International Nuclear Information System (INIS)

Kirk Nordstrom, D.

2012-01-01

Models have become so fashionable that many scientists and engineers cannot imagine working without them. The predominant use of computer codes to execute model calculations has blurred the distinction between code and model. The recent controversy regarding model validation has brought into question what we mean by a ‘model’ and by ‘validation.’ It has become apparent that the usual meaning of validation may be common in engineering practice and seems useful in legal practice but it is contrary to scientific practice and brings into question our understanding of science and how it can best be applied to such problems as hazardous waste characterization, remediation, and aqueous geochemistry in general. This review summarizes arguments against using the phrase model validation and examines efforts to validate models for high-level radioactive waste management and for permitting and monitoring open-pit mines. Part of the controversy comes from a misunderstanding of ‘prediction’ and the need to distinguish logical from temporal prediction. Another problem stems from the difference in the engineering approach contrasted with the scientific approach. The reductionist influence on the way we approach environmental investigations also limits our ability to model the interconnected nature of reality. Guidelines are proposed to improve our perceptions and proper utilization of models. Use of the word ‘validation’ is strongly discouraged when discussing model reliability.

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.

Geographic and temporal validity of prediction models: Different approaches were useful to examine model performance

NARCIS (Netherlands)

P.C. Austin (Peter); D. van Klaveren (David); Y. Vergouwe (Yvonne); D. Nieboer (Daan); D.S. Lee (Douglas); E.W. Steyerberg (Ewout)

2016-01-01

textabstractObjective: Validation of clinical prediction models traditionally refers to the assessment of model performance in new patients. We studied different approaches to geographic and temporal validation in the setting of multicenter data from two time periods. Study Design and Setting: We

Validation of the Colorado Retinopathy of Prematurity Screening Model.

Science.gov (United States)

McCourt, Emily A; Ying, Gui-Shuang; Lynch, Anne M; Palestine, Alan G; Wagner, Brandie D; Wymore, Erica; Tomlinson, Lauren A; Binenbaum, Gil

2018-04-01

The Colorado Retinopathy of Prematurity (CO-ROP) model uses birth weight, gestational age, and weight gain at the first month of life (WG-28) to predict risk of severe retinopathy of prematurity (ROP). In previous validation studies, the model performed very well, predicting virtually all cases of severe ROP and potentially reducing the number of infants who need ROP examinations, warranting validation in a larger, more diverse population. To validate the performance of the CO-ROP model in a large multicenter cohort. This study is a secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study, a retrospective multicenter cohort study conducted in 29 hospitals in the United States and Canada between January 2006 and June 2012 of 6351 premature infants who received ROP examinations. Sensitivity and specificity for severe (early treatment of ROP [ETROP] type 1 or 2) ROP, and reduction in infants receiving examinations. The CO-ROP model was applied to the infants in the G-ROP data set with all 3 data points (infants would have received examinations if they met all 3 criteria: birth weight, large validation cohort. The model requires all 3 criteria to be met to signal a need for examinations, but some infants with a birth weight or gestational age above the thresholds developed severe ROP. Most of these infants who were not detected by the CO-ROP model had obvious deviation in expected weight trajectories or nonphysiologic weight gain. These findings suggest that the CO-ROP model needs to be revised before considering implementation into clinical practice.

Validation of limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring - is a separate validation group required?

NARCIS (Netherlands)

Proost, J. H.

Objective: Limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring are usually validated in a separate group of patients, according to published guidelines. The aim of this study is to evaluate the validation of LSM by comparing independent validation with cross-validation

Validation of a phytoremediation computer model

Energy Technology Data Exchange (ETDEWEB)

Corapcioglu, M Y; Sung, K; Rhykerd, R L; Munster, C; Drew, M [Texas A and M Univ., College Station, TX (United States)

1999-01-01

The use of plants to stimulate remediation of contaminated soil is an effective, low-cost cleanup method which can be applied to many different sites. A phytoremediation computer model has been developed to simulate how recalcitrant hydrocarbons interact with plant roots in unsaturated soil. A study was conducted to provide data to validate and calibrate the model. During the study, lysimeters were constructed and filled with soil contaminated with 10 [mg kg[sub -1

Traffic modelling validation of advanced driver assistance systems

NARCIS (Netherlands)

Tongeren, R. van; Gietelink, O.J.; Schutter, B. de; Verhaegen, M.

2007-01-01

This paper presents a microscopic traffic model for the validation of advanced driver assistance systems. This model describes single-lane traffic and is calibrated with data from a field operational test. To illustrate the use of the model, a Monte Carlo simulation of single-lane traffic scenarios

Verification and Validation of Tropospheric Model/Database

National Research Council Canada - National Science Library

Junho, choi

1998-01-01

A verification and validation of tropospheric models and databases has been performed based on ray tracing algorithm, statistical analysis, test on real time system operation, and other technical evaluation process...

Integrating self-regulated learning and discovery learning into English lesson plan

Directory of Open Access Journals (Sweden)

Sayukti Ni Kadek Heny

2018-01-01

Full Text Available The notion of learner-centeredness has been embedded in the National Curriculum of Indonesia, 2013 Curriculum. However, most of the teachers seem to be hardly acquainted with the concept of Self-Regulated Learning (SRL and discovery learning in the lesson planning. Considering the phenomenon, this study intends to explore the concept of Self-Regulated Learning in the lesson plan of English subject for a tenth-grade level by employing a qualitative design with data obtained from a teacher-made lesson plan and a semi-structured interview. The researcher used content analysis to analyze the lesson plan. Meanwhile, the qualitative data from interview result were preceded through a coding sheet and transcribed modified figure. The findings revealed an integration of SRL cyclical phase and discovery learning in the teacher-made lesson plan. Based on the discussion, the results need to be applied in a considerably large context, in order to see thoroughly dynamic integration between Self-Regulated Learning model, lesson planning and the concept of learner autonomy.

Cost model validation: a technical and cultural approach

Science.gov (United States)

Hihn, J.; Rosenberg, L.; Roust, K.; Warfield, K.

2001-01-01

This paper summarizes how JPL's parametric mission cost model (PMCM) has been validated using both formal statistical methods and a variety of peer and management reviews in order to establish organizational acceptance of the cost model estimates.

Pharmacokinetic modeling of gentamicin in treatment of infective endocarditis: Model development and validation of existing models

Science.gov (United States)

van der Wijk, Lars; Proost, Johannes H.; Sinha, Bhanu; Touw, Daan J.

2017-01-01

Gentamicin shows large variations in half-life and volume of distribution (Vd) within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic models are applied for predicting gentamicin doses in adults. For endocarditis patients the optimal model is unknown. We aimed at: 1) creating an optimal model for endocarditis patients; and 2) assessing whether the endocarditis and existing models can accurately predict serum levels. We performed a retrospective observational two-cohort study: one cohort to parameterize the endocarditis model by iterative two-stage Bayesian analysis, and a second cohort to validate and compare all three models. The Akaike Information Criterion and the weighted sum of squares of the residuals divided by the degrees of freedom were used to select the endocarditis model. Median Prediction Error (MDPE) and Median Absolute Prediction Error (MDAPE) were used to test all models with the validation dataset. We built the endocarditis model based on data from the modeling cohort (65 patients) with a fixed 0.277 L/h/70kg metabolic clearance, 0.698 (±0.358) renal clearance as fraction of creatinine clearance, and Vd 0.312 (±0.076) L/kg corrected lean body mass. External validation with data from 14 validation cohort patients showed a similar predictive power of the endocarditis model (MDPE -1.77%, MDAPE 4.68%) as compared to the intensive-care (MDPE -1.33%, MDAPE 4.37%) and standard (MDPE -0.90%, MDAPE 4.82%) models. All models acceptably predicted pharmacokinetic parameters for gentamicin in endocarditis patients. However, these patients appear to have an increased Vd, similar to intensive care patients. Vd mainly determines the height of peak serum levels, which in turn correlate with bactericidal activity. In order to maintain simplicity, we advise to use the existing intensive-care model in clinical practice to avoid

Pharmacokinetic modeling of gentamicin in treatment of infective endocarditis: Model development and validation of existing models.

Directory of Open Access Journals (Sweden)

Anna Gomes

Full Text Available Gentamicin shows large variations in half-life and volume of distribution (Vd within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic models are applied for predicting gentamicin doses in adults. For endocarditis patients the optimal model is unknown. We aimed at: 1 creating an optimal model for endocarditis patients; and 2 assessing whether the endocarditis and existing models can accurately predict serum levels. We performed a retrospective observational two-cohort study: one cohort to parameterize the endocarditis model by iterative two-stage Bayesian analysis, and a second cohort to validate and compare all three models. The Akaike Information Criterion and the weighted sum of squares of the residuals divided by the degrees of freedom were used to select the endocarditis model. Median Prediction Error (MDPE and Median Absolute Prediction Error (MDAPE were used to test all models with the validation dataset. We built the endocarditis model based on data from the modeling cohort (65 patients with a fixed 0.277 L/h/70kg metabolic clearance, 0.698 (±0.358 renal clearance as fraction of creatinine clearance, and Vd 0.312 (±0.076 L/kg corrected lean body mass. External validation with data from 14 validation cohort patients showed a similar predictive power of the endocarditis model (MDPE -1.77%, MDAPE 4.68% as compared to the intensive-care (MDPE -1.33%, MDAPE 4.37% and standard (MDPE -0.90%, MDAPE 4.82% models. All models acceptably predicted pharmacokinetic parameters for gentamicin in endocarditis patients. However, these patients appear to have an increased Vd, similar to intensive care patients. Vd mainly determines the height of peak serum levels, which in turn correlate with bactericidal activity. In order to maintain simplicity, we advise to use the existing intensive-care model in clinical practice to

Flexible climate modeling systems: Lessons from Snowball Earth, Titan and Mars

Science.gov (United States)

Pierrehumbert, R. T.

2007-12-01

Climate models are only useful to the extent that real understanding can be extracted from them. Most leading- edge problems in climate change, paleoclimate and planetary climate require a high degree of flexibility in terms of incorporating model physics -- for example in allowing methane or CO2 to be a condensible substance instead of water vapor. This puts a premium on model design that allows easy modification, and on physical parameterizations that are close to fundamentals with as little empirical ad-hoc formulation as possible. I will provide examples from two approaches to this problem we have been using at the University of Chicago. The first is the FOAM general circulation model, which is a clean single-executable Fortran-77/c code supported by auxiliary applications in Python and Java. The second is a new approach based on using Python as a shell for assembling building blocks in compiled-code into full models. Applications to Snowball Earth, Titan and Mars, as well as pedagogical uses, will be discussed. One painful lesson we have learned is that Fortran-95 is a major impediment to portability and cross-language interoperability; in this light the trend toward Fortran-95 in major modelling groups is seen as a significant step backwards. In this talk, I will focus on modeling projects employing a full representation of atmospheric fluid dynamics, rather than "intermediate complexity" models in which the associated transports are parameterized.

Towards realistic modelling of spectral line formation - lessons learnt from red giants

Science.gov (United States)

Lind, Karin

2015-08-01

Many decades of quantitative spectroscopic studies of red giants have revealed much about the formation histories and interlinks between the main components of the Galaxy and its satellites. Telescopes and instrumentation are now able to deliver high-resolution data of superb quality for large stellar samples and Galactic archaeology has entered a new era. At the same time, we have learnt how simplifying physical assumptions in the modelling of spectroscopic data can bias the interpretations, in particular one-dimensional homogeneity and local thermodynamic equilibrium (LTE). I will present lessons learnt so far from non-LTE spectral line formation in 3D radiation-hydrodynamic atmospheres of red giants, the smaller siblings of red supergiants.

Validation and calibration of structural models that combine information from multiple sources.

Science.gov (United States)

Dahabreh, Issa J; Wong, John B; Trikalinos, Thomas A

2017-02-01

Mathematical models that attempt to capture structural relationships between their components and combine information from multiple sources are increasingly used in medicine. Areas covered: We provide an overview of methods for model validation and calibration and survey studies comparing alternative approaches. Expert commentary: Model validation entails a confrontation of models with data, background knowledge, and other models, and can inform judgments about model credibility. Calibration involves selecting parameter values to improve the agreement of model outputs with data. When the goal of modeling is quantitative inference on the effects of interventions or forecasting, calibration can be viewed as estimation. This view clarifies issues related to parameter identifiability and facilitates formal model validation and the examination of consistency among different sources of information. In contrast, when the goal of modeling is the generation of qualitative insights about the modeled phenomenon, calibration is a rather informal process for selecting inputs that result in model behavior that roughly reproduces select aspects of the modeled phenomenon and cannot be equated to an estimation procedure. Current empirical research on validation and calibration methods consists primarily of methodological appraisals or case-studies of alternative techniques and cannot address the numerous complex and multifaceted methodological decisions that modelers must make. Further research is needed on different approaches for developing and validating complex models that combine evidence from multiple sources.

Application of parameters space analysis tools for empirical model validation

Energy Technology Data Exchange (ETDEWEB)

Paloma del Barrio, E. [LEPT-ENSAM UMR 8508, Talence (France); Guyon, G. [Electricite de France, Moret-sur-Loing (France)

2004-01-01

A new methodology for empirical model validation has been proposed in the framework of the Task 22 (Building Energy Analysis Tools) of the International Energy Agency. It involves two main steps: checking model validity and diagnosis. Both steps, as well as the underlying methods, have been presented in the first part of the paper. In this part, they are applied for testing modelling hypothesis in the framework of the thermal analysis of an actual building. Sensitivity analysis tools have been first used to identify the parts of the model that can be really tested on the available data. A preliminary diagnosis is then supplied by principal components analysis. Useful information for model behaviour improvement has been finally obtained by optimisation techniques. This example of application shows how model parameters space analysis is a powerful tool for empirical validation. In particular, diagnosis possibilities are largely increased in comparison with residuals analysis techniques. (author)

Validation analysis of probabilistic models of dietary exposure to food additives.

Science.gov (United States)

Gilsenan, M B; Thompson, R L; Lambe, J; Gibney, M J

2003-10-01

The validity of a range of simple conceptual models designed specifically for the estimation of food additive intakes using probabilistic analysis was assessed. Modelled intake estimates that fell below traditional conservative point estimates of intake and above 'true' additive intakes (calculated from a reference database at brand level) were considered to be in a valid region. Models were developed for 10 food additives by combining food intake data, the probability of an additive being present in a food group and additive concentration data. Food intake and additive concentration data were entered as raw data or as a lognormal distribution, and the probability of an additive being present was entered based on the per cent brands or the per cent eating occasions within a food group that contained an additive. Since the three model components assumed two possible modes of input, the validity of eight (2(3)) model combinations was assessed. All model inputs were derived from the reference database. An iterative approach was employed in which the validity of individual model components was assessed first, followed by validation of full conceptual models. While the distribution of intake estimates from models fell below conservative intakes, which assume that the additive is present at maximum permitted levels (MPLs) in all foods in which it is permitted, intake estimates were not consistently above 'true' intakes. These analyses indicate the need for more complex models for the estimation of food additive intakes using probabilistic analysis. Such models should incorporate information on market share and/or brand loyalty.

Continuous validation of ASTEC containment models and regression testing

International Nuclear Information System (INIS)

Nowack, Holger; Reinke, Nils; Sonnenkalb, Martin

2014-01-01

The focus of the ASTEC (Accident Source Term Evaluation Code) development at GRS is primarily on the containment module CPA (Containment Part of ASTEC), whose modelling is to a large extent based on the GRS containment code COCOSYS (COntainment COde SYStem). Validation is usually understood as the approval of the modelling capabilities by calculations of appropriate experiments done by external users different from the code developers. During the development process of ASTEC CPA, bugs and unintended side effects may occur, which leads to changes in the results of the initially conducted validation. Due to the involvement of a considerable number of developers in the coding of ASTEC modules, validation of the code alone, even if executed repeatedly, is not sufficient. Therefore, a regression testing procedure has been implemented in order to ensure that the initially obtained validation results are still valid with succeeding code versions. Within the regression testing procedure, calculations of experiments and plant sequences are performed with the same input deck but applying two different code versions. For every test-case the up-to-date code version is compared to the preceding one on the basis of physical parameters deemed to be characteristic for the test-case under consideration. In the case of post-calculations of experiments also a comparison to experimental data is carried out. Three validation cases from the regression testing procedure are presented within this paper. The very good post-calculation of the HDR E11.1 experiment shows the high quality modelling of thermal-hydraulics in ASTEC CPA. Aerosol behaviour is validated on the BMC VANAM M3 experiment, and the results show also a very good agreement with experimental data. Finally, iodine behaviour is checked in the validation test-case of the THAI IOD-11 experiment. Within this test-case, the comparison of the ASTEC versions V2.0r1 and V2.0r2 shows how an error was detected by the regression testing

Ensuring the Validity of the Micro Foundation in DSGE Models

DEFF Research Database (Denmark)

Andreasen, Martin Møller

& Primiceri (American Economic Review, forth- coming) and Fernández-Villaverde & Rubio-Ramírez (Review of Economic Studies, 2007) do not satisfy these sufficient conditions, or any other known set of conditions ensuring finite values for the objective functions. Thus, the validity of the micro foundation......The presence of i) stochastic trends, ii) deterministic trends, and/or iii) stochastic volatil- ity in DSGE models may imply that the agents' objective functions attain infinite values. We say that such models do not have a valid micro foundation. The paper derives sufficient condi- tions which...... ensure that the objective functions of the households and the firms are finite even when various trends and stochastic volatility are included in a standard DSGE model. Based on these conditions we test the validity of the micro foundation in six DSGE models from the literature. The models of Justiniano...

Lessons from Mouse Models of High-Fat Diet-Induced NAFLD

Directory of Open Access Journals (Sweden)

Yasuo Terauchi

2013-10-01

Full Text Available Nonalcoholic fatty liver disease (NAFLD encompasses a clinicopathologic spectrum of diseases ranging from isolated hepatic steatosis to nonalcoholic steatohepatitis (NASH, the more aggressive form of fatty liver disease that may progress to cirrhosis and cirrhosis-related complications, including hepatocellular carcinoma. The prevalence of NAFLD, including NASH, is also increasing in parallel with the growing epidemics of obesity and diabetes. However, the causal relationships between obesity and/or diabetes and NASH or liver tumorigenesis have not yet been clearly elucidated. Animal models of NAFLD/NASH provide crucial information, not only for elucidating the pathogenesis of NAFLD/NASH, but also for examining therapeutic effects of various agents. A high-fat diet is widely used to produce hepatic steatosis and NASH in experimental animals. Several studies, including our own, have shown that long-term high-fat diet loading, which can induce obesity and insulin resistance, can also induce NASH and liver tumorigenesis in C57BL/6J mice. In this article, we discuss the pathophysiology of and treatment strategies for NAFLD and subsequent NAFLD-related complications such as NASH and liver tumorigenesis, mainly based on lessons learned from mouse models of high-fat diet-induced NAFLD/NASH.

Benchmark validation of statistical models: Application to mediation analysis of imagery and memory.

Science.gov (United States)

MacKinnon, David P; Valente, Matthew J; Wurpts, Ingrid C

2018-03-29

This article describes benchmark validation, an approach to validating a statistical model. According to benchmark validation, a valid model generates estimates and research conclusions consistent with a known substantive effect. Three types of benchmark validation-(a) benchmark value, (b) benchmark estimate, and (c) benchmark effect-are described and illustrated with examples. Benchmark validation methods are especially useful for statistical models with assumptions that are untestable or very difficult to test. Benchmark effect validation methods were applied to evaluate statistical mediation analysis in eight studies using the established effect that increasing mental imagery improves recall of words. Statistical mediation analysis led to conclusions about mediation that were consistent with established theory that increased imagery leads to increased word recall. Benchmark validation based on established substantive theory is discussed as a general way to investigate characteristics of statistical models and a complement to mathematical proof and statistical simulation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Customer service as an act of(f balance: lessons for the tourism and hospitality industry

Directory of Open Access Journals (Sweden)

S Henning

2014-01-01

Full Text Available This article reports on corporate customers' perceptions of a telecommunications organisation in South Africa and the lessons learned for the tourism industry. The purpose of the research was to explore reasons for the decline in customers' perceptions of overall quality of service at Telematics SA from a systems theory perspective. The Three State Triangle model (Henning, 2009 was presented as the three dynamic states of all living systems, including businesses and industries. The states were identified as Stable equilibrium (Se, Explosive instability (Ei and Bounded instability (Bi. The model was applied to interpret the findings and offered a way to interpret customer experiences at Telematics SA. Qualitative research was the chosen method of inquiry. A card game was the conversational instrument used to conduct 10 in-depth interviews with Virtual Private Network customers. Purposeful sampling fitted the rationale of the study. Content analysis was done to identify coding categories, while touch-point validity confirmed that the findings were aligned with the systems theoretical concepts. The research methodology can be applied as a qualitative diagnostic tool in different business contexts, while the Three State Triangle model reveals the underlying dynamic processes in organisations. The research results are applied as lessons to be learned for the continuous improvement of products and services of businesses in the hospitality and tourism industry. Businesses should not get stuck in old strategies and policies but adopt a state of Bounded instability where innovation and renewal is possible.

Cross-validation of an employee safety climate model in Malaysia.

Science.gov (United States)

Bahari, Siti Fatimah; Clarke, Sharon

2013-06-01

Whilst substantial research has investigated the nature of safety climate, and its importance as a leading indicator of organisational safety, much of this research has been conducted with Western industrial samples. The current study focuses on the cross-validation of a safety climate model in the non-Western industrial context of Malaysian manufacturing. The first-order factorial validity of Cheyne et al.'s (1998) [Cheyne, A., Cox, S., Oliver, A., Tomas, J.M., 1998. Modelling safety climate in the prediction of levels of safety activity. Work and Stress, 12(3), 255-271] model was tested, using confirmatory factor analysis, in a Malaysian sample. Results showed that the model fit indices were below accepted levels, indicating that the original Cheyne et al. (1998) safety climate model was not supported. An alternative three-factor model was developed using exploratory factor analysis. Although these findings are not consistent with previously reported cross-validation studies, we argue that previous studies have focused on validation across Western samples, and that the current study demonstrates the need to take account of cultural factors in the development of safety climate models intended for use in non-Western contexts. The results have important implications for the transferability of existing safety climate models across cultures (for example, in global organisations) and highlight the need for future research to examine cross-cultural issues in relation to safety climate. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Research-design model for professional development of teachers: Designing lessons with physics education research

Science.gov (United States)

Eylon, Bat-Sheva; Bagno, Esther

2006-12-01

How can one increase the awareness of teachers to the existence and importance of knowledge gained through physics education research (PER) and provide them with capabilities to use it? How can one enrich teachers’ physics knowledge and the related pedagogical content knowledge of topics singled out by PER? In this paper we describe a professional development model that attempts to respond to these needs. We report on a study of the model’s implementation in a program for 22 high-school experienced physics teachers. In this program teachers (in teams of 5-6) developed during a year and a half (about 330h ), several lessons (minimodules) dealing with a topic identified as problematic by PER. The teachers employed a systematic research-based approach and used PER findings. The program consisted of three stages, each culminating with a miniconference: 1. Defining teaching and/or learning goals based on content analysis and diagnosis of students’ prior knowledge. 2. Designing the lessons using PER-based instructional strategies. 3. Performing a small-scale research study that accompanies the development process and publishing the results. We describe a case study of one of the groups and bring evidence that demonstrates how the workshop advanced: (a) Teachers’ awareness of deficiencies in their own knowledge of physics and pedagogy, and their perceptions about their students’ knowledge; (b) teachers’ knowledge of physics and physics pedagogy; (c) a systematic research-based approach to the design of lessons; (d) the formation of a community of practice; and (e) acquaintance with central findings of PER. There was a clear effect on teachers’ practice in the context of the study as indicated by the materials brought to the workshop. The teachers also reported that they continued to use the insights gained, mainly in the topics that were investigated by themselves and by their peers.

Research-design model for professional development of teachers: Designing lessons with physics education research

Directory of Open Access Journals (Sweden)

Esther Bagno

2006-09-01

Full Text Available How can one increase the awareness of teachers to the existence and importance of knowledge gained through physics education research (PER and provide them with capabilities to use it? How can one enrich teachers’ physics knowledge and the related pedagogical content knowledge of topics singled out by PER? In this paper we describe a professional development model that attempts to respond to these needs. We report on a study of the model’s implementation in a program for 22 high-school experienced physics teachers. In this program teachers (in teams of 5-6 developed during a year and a half (about 330 h , several lessons (minimodules dealing with a topic identified as problematic by PER. The teachers employed a systematic research-based approach and used PER findings. The program consisted of three stages, each culminating with a miniconference: 1. Defining teaching and/or learning goals based on content analysis and diagnosis of students’ prior knowledge. 2. Designing the lessons using PER-based instructional strategies. 3. Performing a small-scale research study that accompanies the development process and publishing the results. We describe a case study of one of the groups and bring evidence that demonstrates how the workshop advanced: (a Teachers’ awareness of deficiencies in their own knowledge of physics and pedagogy, and their perceptions about their students’ knowledge; (b teachers’ knowledge of physics and physics pedagogy; (c a systematic research-based approach to the design of lessons; (d the formation of a community of practice; and (e acquaintance with central findings of PER. There was a clear effect on teachers’ practice in the context of the study as indicated by the materials brought to the workshop. The teachers also reported that they continued to use the insights gained, mainly in the topics that were investigated by themselves and by their peers.

Research-design model for professional development of teachers: Designing lessons with physics education research

Directory of Open Access Journals (Sweden)

Bat-Sheva Eylon

2006-09-01

Full Text Available How can one increase the awareness of teachers to the existence and importance of knowledge gained through physics education research (PER and provide them with capabilities to use it? How can one enrich teachers’ physics knowledge and the related pedagogical content knowledge of topics singled out by PER? In this paper we describe a professional development model that attempts to respond to these needs. We report on a study of the model’s implementation in a program for 22 high-school experienced physics teachers. In this program teachers (in teams of 5-6 developed during a year and a half (about 330h, several lessons (minimodules dealing with a topic identified as problematic by PER. The teachers employed a systematic research-based approach and used PER findings. The program consisted of three stages, each culminating with a miniconference: 1. Defining teaching and/or learning goals based on content analysis and diagnosis of students’ prior knowledge. 2. Designing the lessons using PER-based instructional strategies. 3. Performing a small-scale research study that accompanies the development process and publishing the results. We describe a case study of one of the groups and bring evidence that demonstrates how the workshop advanced: (a Teachers’ awareness of deficiencies in their own knowledge of physics and pedagogy, and their perceptions about their students’ knowledge; (b teachers’ knowledge of physics and physics pedagogy; (c a systematic research-based approach to the design of lessons; (d the formation of a community of practice; and (e acquaintance with central findings of PER. There was a clear effect on teachers’ practice in the context of the study as indicated by the materials brought to the workshop. The teachers also reported that they continued to use the insights gained, mainly in the topics that were investigated by themselves and by their peers.

Estimation of radionuclide ingestion: Lessons from dose reconstruction for fallout from the Nevada Test Site

International Nuclear Information System (INIS)

Breshears, D.D.; Whicker, F.W.; Kirchner, T.B.; Anspaugh, L.R.

1994-01-01

The United States conducted atmospheric testing of nuclear devices at the Nevada Test Site from 1951 through 1963. In 1979 the U.S. Department of Energy established the Off-Site Radiation Exposure Review Project to compile a data base related to health effects from nuclear testing and to reconstruct doses to public residing off of the Nevada Test Site. This project is the most comprehensive dose reconstruction project to date, and, since similar assessments are currently underway at several other locations within and outside the U.S., lessons from ORERP can be valuable. A major component of dose reconstruction is estimation of dose from radionuclide ingestion. The PATHWAY food-chain model was developed to estimate the amount of radionuclides ingested. For agricultural components of the human diet, PATHWAY predicts radionuclide concentrations and quantities ingested. To improve accuracy and model credibility, four components of model analysis were conducted: estimation of uncertainty in model predictions, estimation of sensitivity of model predictions to input parameters, and testing of model predictions against independent data (validation), and comparing predictions from PATHWAY with those from other models. These results identified strengths and weaknesses in the model and aided in establishing the confidence associated with model prediction, which is a critical component risk assessment and dose reconstruction. For fallout from the Nevada Test Site, by far, the largest internal doses were received by the thyroid. However, the predicted number of fatal cancers from ingestion dose was generally much smaller than the number predicted from external dose. The number of fatal cancers predicted from ingestion dose was also orders of magnitude below the normal projected cancer rate. Several lessons were learned during the study that are relevant to other dose reconstruction efforts

A Lesson about the Circular Flow. Active Learning Lessons. Economics International.

Science.gov (United States)

Landfried, Janet

This lesson plan was developed through "Economics International," an international program to help build economic education infrastructures in the emerging market economies. It provides a lesson description; appropriate grade level; economic concepts; content standards and benchmarks; related subjects; instructional objectives; time…

Statistical methods for mechanistic model validation: Salt Repository Project

International Nuclear Information System (INIS)

Eggett, D.L.

1988-07-01

As part of the Department of Energy's Salt Repository Program, Pacific Northwest Laboratory (PNL) is studying the emplacement of nuclear waste containers in a salt repository. One objective of the SRP program is to develop an overall waste package component model which adequately describes such phenomena as container corrosion, waste form leaching, spent fuel degradation, etc., which are possible in the salt repository environment. The form of this model will be proposed, based on scientific principles and relevant salt repository conditions with supporting data. The model will be used to predict the future characteristics of the near field environment. This involves several different submodels such as the amount of time it takes a brine solution to contact a canister in the repository, how long it takes a canister to corrode and expose its contents to the brine, the leach rate of the contents of the canister, etc. These submodels are often tested in a laboratory and should be statistically validated (in this context, validate means to demonstrate that the model adequately describes the data) before they can be incorporated into the waste package component model. This report describes statistical methods for validating these models. 13 refs., 1 fig., 3 tabs

Predicting the ungauged basin: Model validation and realism assessment

Directory of Open Access Journals (Sweden)

Tim evan Emmerik

2015-10-01

Full Text Available The hydrological decade on Predictions in Ungauged Basins (PUB led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of model outcome has not been discussed to a great extent. With this paper we aim to contribute to the discussion on how one can determine the value and validity of a hydrological model developed for an ungauged basin. As in many cases no local, or even regional, data are available, alternative methods should be applied. Using a PUB case study in a genuinely ungauged basin in southern Cambodia, we give several examples of how one can use different types of soft data to improve model design, calibrate and validate the model, and assess the realism of the model output. A rainfall-runoff model was coupled to an irrigation reservoir, allowing the use of additional and unconventional data. The model was mainly forced with remote sensing data, and local knowledge was used to constrain the parameters. Model realism assessment was done using data from surveys. This resulted in a successful reconstruction of the reservoir dynamics, and revealed the different hydrological characteristics of the two topographical classes. This paper does not present a generic approach that can be transferred to other ungauged catchments, but it aims to show how clever model design and alternative data acquisition can result in a valuable hydrological model for an ungauged catchment.

Validating firn compaction model with remote sensing data

DEFF Research Database (Denmark)

Simonsen, S. B.; Stenseng, Lars; Sørensen, Louise Sandberg

A comprehensive understanding of firn processes is of outmost importance, when estimating present and future changes of the Greenland Ice Sheet. Especially, when remote sensing altimetry is used to assess the state of ice sheets and their contribution to global sea level rise, firn compaction...... models have been shown to be a key component. Now, remote sensing data can also be used to validate the firn models. Radar penetrating the upper part of the firn column in the interior part of Greenland shows a clear layering. The observed layers from the radar data can be used as an in-situ validation...... correction relative to the changes in the elevation of the surface observed with remote sensing altimetry? What model time resolution is necessary to resolved the observed layering? What model refinements are necessary to give better estimates of the surface mass balance of the Greenland ice sheet from...

When do Armed Revolts Succeed: Lessons from Lanchester Theory

Science.gov (United States)

2011-10-01

When do Armed Revolts Succeed: Lessons from Lanchester Theory Michael P. Atkinson 1, Alexander Gutfraind 2, Moshe Kress 1 Abstract Major revolts have...classic Lanchester theory of combat. The model accounts for the split in the population between those loyal to the regime and those favoring the...Lessons from Lanchester Theory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

Classroom Management and Lesson Planning(4)

Institute of Scientific and Technical Information of China (English)

2006-01-01

Lesson PlanningTask 1As teachers,we all need to plan our lessons before we teach.Make a list of things that you think need tobe included in a lesson plan.Then compare and discuss your list with another teacher.Also think about reasonswhy we need to plan our lessons.

PEMFC modeling and experimental validation

Energy Technology Data Exchange (ETDEWEB)

Vargas, J.V.C. [Federal University of Parana (UFPR), Curitiba, PR (Brazil). Dept. of Mechanical Engineering], E-mail: jvargas@demec.ufpr.br; Ordonez, J.C.; Martins, L.S. [Florida State University, Tallahassee, FL (United States). Center for Advanced Power Systems], Emails: ordonez@caps.fsu.edu, martins@caps.fsu.edu

2009-07-01

In this paper, a simplified and comprehensive PEMFC mathematical model introduced in previous studies is experimentally validated. Numerical results are obtained for an existing set of commercial unit PEM fuel cells. The model accounts for pressure drops in the gas channels, and for temperature gradients with respect to space in the flow direction, that are investigated by direct infrared imaging, showing that even at low current operation such gradients are present in fuel cell operation, and therefore should be considered by a PEMFC model, since large coolant flow rates are limited due to induced high pressure drops in the cooling channels. The computed polarization and power curves are directly compared to the experimentally measured ones with good qualitative and quantitative agreement. The combination of accuracy and low computational time allow for the future utilization of the model as a reliable tool for PEMFC simulation, control, design and optimization purposes. (author)

Plant lessons: exploring ABCB functionality through structural modeling

Directory of Open Access Journals (Sweden)

Aurélien eBailly

2012-01-01

Full Text Available In contrast to mammalian ABCB1 proteins, narrow substrate specificity has been extensively documented for plant orthologs shown to catalyze the transport of the plant hormone, auxin. Using the crystal structures of the multidrug exporters Sav1866 and MmABCB1 as templates, we have developed structural models of plant ABCB proteins with a common architecture. Comparisons of these structures identified kingdom-specific candidate substrate-binding regions within the translocation chamber formed by the transmembrane domains of ABCBs from the model plant Arabidopsis. These results suggest an early evolutionary divergence of plant and mammalian ABCBs. Validation of these models becomes a priority for efforts to elucidate ABCB function and manipulate this class of transporters to enhance plant productivity and quality.

Some guidance on preparing validation plans for the DART Full System Models.

Energy Technology Data Exchange (ETDEWEB)

Gray, Genetha Anne; Hough, Patricia Diane; Hills, Richard Guy (Sandia National Laboratories, Albuquerque, NM)

2009-03-01

Planning is an important part of computational model verification and validation (V&V) and the requisite planning document is vital for effectively executing the plan. The document provides a means of communicating intent to the typically large group of people, from program management to analysts to test engineers, who must work together to complete the validation activities. This report provides guidelines for writing a validation plan. It describes the components of such a plan and includes important references and resources. While the initial target audience is the DART Full System Model teams in the nuclear weapons program, the guidelines are generally applicable to other modeling efforts. Our goal in writing this document is to provide a framework for consistency in validation plans across weapon systems, different types of models, and different scenarios. Specific details contained in any given validation plan will vary according to application requirements and available resources.

Constellation Program Lessons Learned. Volume 2; Detailed Lessons Learned

Science.gov (United States)

Rhatigan, Jennifer; Neubek, Deborah J.; Thomas, L. Dale

2011-01-01

These lessons learned are part of a suite of hardware, software, test results, designs, knowledge base, and documentation that comprises the legacy of the Constellation Program. The context, summary information, and lessons learned are presented in a factual format, as known and described at the time. While our opinions might be discernable in the context, we have avoided all but factually sustainable statements. Statements should not be viewed as being either positive or negative; their value lies in what we did and what we learned that is worthy of passing on. The lessons include both "dos" and "don ts." In many cases, one person s "do" can be viewed as another person s "don t"; therefore, we have attempted to capture both perspectives when applicable and useful. While Volume I summarizes the views of those who managed the program, this Volume II encompasses the views at the working level, describing how the program challenges manifested in day-to-day activities. Here we see themes that were perhaps hinted at, but not completely addressed, in Volume I: unintended consequences of policies that worked well at higher levels but lacked proper implementation at the working level; long-term effects of the "generation gap" in human space flight development, the need to demonstrate early successes at the expense of thorough planning, and the consequences of problems and challenges not yet addressed because other problems and challenges were more immediate or manifest. Not all lessons learned have the benefit of being operationally vetted, since the program was cancelled shortly after Preliminary Design Review. We avoid making statements about operational consequences (with the exception of testing and test flights that did occur), but we do attempt to provide insight into how operational thinking influenced design and testing. The lessons have been formatted with a description, along with supporting information, a succinct statement of the lesson learned, and

Studying Validity of Single-Fluid Model in Inertial Confinement Fusion

International Nuclear Information System (INIS)

Gu Jian-Fa; Fan Zheng-Feng; Dai Zhen-Sheng; Ye Wen-Hua; Pei Wen-Bing; Zhu Shao-Ping

2014-01-01

The validity of single-fluid model in inertial confinement fusion simulations is studied by comparing the results of the multi- and single-fluid models. The multi-fluid model includes the effects of collision and interpenetration between fluid species. By simulating the collision of fluid species, steady-state shock propagation into the thin DT gas and expansion of hohlraum Au wall heated by lasers, the results show that the validity of single-fluid model is strongly dependent on the ratio of the characteristic length of the simulated system to the particle mean free path. When the characteristic length L is one order larger than the mean free path λ, the single-fluid model's results are found to be in good agreement with the multi-fluid model's simulations, and the modeling of single-fluid remains valid. If the value of L/λ is lower than 10, the interpenetration between fluid species is significant, and the single-fluid simulations show some unphysical results; while the multi-fluid model can describe well the interpenetration and mix phenomena, and give more reasonable results. (physics of gases, plasmas, and electric discharges)

Classroom Management and Lesson Planning(4)

Institute of Scientific and Technical Information of China (English)

2006-01-01

@@ Lesson Planning Task 1 As teachers,we all need to plan our lessons before we teach.Make a list of things that you think need to be included in a lesson plan.Then compare and discuss your list with another teacher.Also think about reasons why we need to plan our lessons.

ADVISHE: A new tool to report validation of health-economic decision models

NARCIS (Netherlands)

Vemer, P.; Corro Ramos, I.; Van Voorn, G.; Al, M.J.; Feenstra, T.L.

2014-01-01

Background: Modelers and reimbursement decision makers could both profit from a more systematic reporting of the efforts to validate health-economic (HE) models. Objectives: Development of a tool to systematically report validation efforts of HE decision models and their outcomes. Methods: A gross

Lesson Planning the Kodaly Way.

Science.gov (United States)

Boshkoff, Ruth

1991-01-01

Discusses the contribution of Zoltan Kodaly to music lesson planning. Emphasizes preparation, presentation, and practice as the three important strategies in teaching concepts and skills to be included in a lesson plan. Includes a sample lesson plan covering a semester and advice on choosing song material. (DK)

Validating a continental-scale groundwater diffuse pollution model using regional datasets.

Science.gov (United States)

Ouedraogo, Issoufou; Defourny, Pierre; Vanclooster, Marnik

2017-12-11

In this study, we assess the validity of an African-scale groundwater pollution model for nitrates. In a previous study, we identified a statistical continental-scale groundwater pollution model for nitrate. The model was identified using a pan-African meta-analysis of available nitrate groundwater pollution studies. The model was implemented in both Random Forest (RF) and multiple regression formats. For both approaches, we collected as predictors a comprehensive GIS database of 13 spatial attributes, related to land use, soil type, hydrogeology, topography, climatology, region typology, nitrogen fertiliser application rate, and population density. In this paper, we validate the continental-scale model of groundwater contamination by using a nitrate measurement dataset from three African countries. We discuss the issue of data availability, and quality and scale issues, as challenges in validation. Notwithstanding that the modelling procedure exhibited very good success using a continental-scale dataset (e.g. R 2  = 0.97 in the RF format using a cross-validation approach), the continental-scale model could not be used without recalibration to predict nitrate pollution at the country scale using regional data. In addition, when recalibrating the model using country-scale datasets, the order of model exploratory factors changes. This suggests that the structure and the parameters of a statistical spatially distributed groundwater degradation model for the African continent are strongly scale dependent.

Validation of spectral gas radiation models under oxyfuel conditions

Energy Technology Data Exchange (ETDEWEB)

Becher, Johann Valentin

2013-05-15

Combustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition than combustion with air. Standard computational-fluid-dynamics (CFD) spectral gas radiation models for air combustion are therefore out of their validity range in oxyfuel combustion. This thesis provides a common spectral basis for the validation of new spectral models. A literature review about fundamental gas radiation theory, spectral modeling and experimental methods provides the reader with a basic understanding of the topic. In the first results section, this thesis validates detailed spectral models with high resolution spectral measurements in a gas cell with the aim of recommending one model as the best benchmark model. In the second results section, spectral measurements from a turbulent natural gas flame - as an example for a technical combustion process - are compared to simulated spectra based on measured gas atmospheres. The third results section compares simplified spectral models to the benchmark model recommended in the first results section and gives a ranking of the proposed models based on their accuracy. A concluding section gives recommendations for the selection and further development of simplified spectral radiation models. Gas cell transmissivity spectra in the spectral range of 2.4 - 5.4 {mu}m of water vapor and carbon dioxide in the temperature range from 727 C to 1500 C and at different concentrations were compared in the first results section at a nominal resolution of 32 cm{sup -1} to line-by-line models from different databases, two statistical-narrow-band models and the exponential-wide-band model. The two statistical-narrow-band models EM2C and RADCAL showed good agreement with a maximal band transmissivity deviation of 3 %. The exponential-wide-band model showed a deviation of 6 %. The new line-by-line database HITEMP2010 had the lowest band transmissivity deviation of 2.2% and was therefore recommended as a reference model for the

Contact Modelling in Resistance Welding, Part II: Experimental Validation

DEFF Research Database (Denmark)

Song, Quanfeng; Zhang, Wenqi; Bay, Niels

2006-01-01

Contact algorithms in resistance welding presented in the previous paper are experimentally validated in the present paper. In order to verify the mechanical contact algorithm, two types of experiments, i.e. sandwich upsetting of circular, cylindrical specimens and compression tests of discs...... with a solid ring projection towards a flat ring, are carried out at room temperature. The complete algorithm, involving not only the mechanical model but also the thermal and electrical models, is validated by projection welding experiments. The experimental results are in satisfactory agreement...

Validation of Power Requirement Model for Active Loudspeakers

DEFF Research Database (Denmark)

Schneider, Henrik; Madsen, Anders Normann; Bjerregaard, Ruben

2015-01-01

. There are however many advantages that could be harvested from such knowledge like size, cost and efficiency improvements. In this paper a recently proposed power requirement model for active loudspeakers is experimentally validated and the model is expanded to include the closed and vented type enclosures...

Progress in Geant4 Electromagnetic Physics Modelling and Validation

International Nuclear Information System (INIS)

Apostolakis, J; Burkhardt, H; Ivanchenko, V N; Asai, M; Bagulya, A; Grichine, V; Brown, J M C; Chikuma, N; Cortes-Giraldo, M A; Elles, S; Jacquemier, J; Guatelli, S; Incerti, S; Kadri, O; Maire, M; Urban, L; Pandola, L; Sawkey, D; Toshito, T; Yamashita, T

2015-01-01

In this work we report on recent improvements in the electromagnetic (EM) physics models of Geant4 and new validations of EM physics. Improvements have been made in models of the photoelectric effect, Compton scattering, gamma conversion to electron and muon pairs, fluctuations of energy loss, multiple scattering, synchrotron radiation, and high energy positron annihilation. The results of these developments are included in the new Geant4 version 10.1 and in patches to previous versions 9.6 and 10.0 that are planned to be used for production for run-2 at LHC. The Geant4 validation suite for EM physics has been extended and new validation results are shown in this work. In particular, the effect of gamma-nuclear interactions on EM shower shape at LHC energies is discussed. (paper)

Analysing the integration of engineering in science lessons with the Engineering-Infused Lesson Rubric

Science.gov (United States)

Peterman, Karen; Daugherty, Jenny L.; Custer, Rodney L.; Ross, Julia M.

2017-09-01

Science teachers are being called on to incorporate engineering practices into their classrooms. This study explores whether the Engineering-Infused Lesson Rubric, a new rubric designed to target best practices in engineering education, could be used to evaluate the extent to which engineering is infused into online science lessons. Eighty lessons were selected at random from three online repositories, and coded with the rubric. Overall results documented the strengths of existing lessons, as well as many components that teachers might strengthen. In addition, a subset of characteristics was found to distinguish lessons with the highest level of engineering infusion. Findings are discussed in relation to the potential of the rubric to help teachers use research evidence-informed practice generally, and in relation to the new content demands of the U.S. Next Generation Science Standards, in particular.

Accounting for treatment use when validating a prognostic model: a simulation study.

Science.gov (United States)

Pajouheshnia, Romin; Peelen, Linda M; Moons, Karel G M; Reitsma, Johannes B; Groenwold, Rolf H H

2017-07-14

Prognostic models often show poor performance when applied to independent validation data sets. We illustrate how treatment use in a validation set can affect measures of model performance and present the uses and limitations of available analytical methods to account for this using simulated data. We outline how the use of risk-lowering treatments in a validation set can lead to an apparent overestimation of risk by a prognostic model that was developed in a treatment-naïve cohort to make predictions of risk without treatment. Potential methods to correct for the effects of treatment use when testing or validating a prognostic model are discussed from a theoretical perspective.. Subsequently, we assess, in simulated data sets, the impact of excluding treated individuals and the use of inverse probability weighting (IPW) on the estimated model discrimination (c-index) and calibration (observed:expected ratio and calibration plots) in scenarios with different patterns and effects of treatment use. Ignoring the use of effective treatments in a validation data set leads to poorer model discrimination and calibration than would be observed in the untreated target population for the model. Excluding treated individuals provided correct estimates of model performance only when treatment was randomly allocated, although this reduced the precision of the estimates. IPW followed by exclusion of the treated individuals provided correct estimates of model performance in data sets where treatment use was either random or moderately associated with an individual's risk when the assumptions of IPW were met, but yielded incorrect estimates in the presence of non-positivity or an unobserved confounder. When validating a prognostic model developed to make predictions of risk without treatment, treatment use in the validation set can bias estimates of the performance of the model in future targeted individuals, and should not be ignored. When treatment use is random, treated

With Interest It Comes To...Unconscionable Clauses in Sales Contracts. A Student's Lesson Plan [and] A Teacher's Lesson Plan [and] A Lawyer's Lesson Plan.

Science.gov (United States)

Howard, Estelle; And Others

One of a series of secondary level teaching units presenting case studies with pro and con analysis of particular legal problems, the document presents a student's lesson plan, a teacher's lesson plan, and a lawyer's lesson plan on unconscionable clauses in sales contracts. The unit acquaints students with the operation of sales contracts and…

Validation of dispersion model of RTARC-DSS based on ''KIT'' field experiments

International Nuclear Information System (INIS)

Duran, J.

2000-01-01

The aim of this study is to present the performance of the Gaussian dispersion model RTARC-DSS (Real Time Accident Release Consequences - Decision Support System) at the 'Kit' field experiments. The Model Validation Kit is a collection of three experimental data sets from Kincaid, Copenhagen, Lillestrom and supplementary Indianopolis experimental campaigns accompanied by software for model evaluation. The validation of the model has been performed on the basis of the maximum arc-wise concentrations using the Bootstrap resampling procedure the variation of the model residuals. Validation was performed for the short-range distances (about 1 - 10 km, maximum for Kincaid data set - 50 km from source). Model evaluation procedure and amount of relative over- or under-prediction are discussed and compared with the model. (author)

Satl model lesson in chemical kinetics | Nazir | African Journal of ...

African Journals Online (AJOL)

Studies in order to pursue kinetics and mechanism of chemical reactions are a vital component of chemical literature. SATL literature is still not available for promoting this vital aspect of chemistry teaching. A lesson pertaining to this important issue has been developed and various parameters of kinetic studies are ...

Development and demonstration of a validation methodology for vehicle lateral dynamics simulation models

Energy Technology Data Exchange (ETDEWEB)

Kutluay, Emir

2013-02-01

In this thesis a validation methodology to be used in the assessment of the vehicle dynamics simulation models is presented. Simulation of vehicle dynamics is used to estimate the dynamic responses of existing or proposed vehicles and has a wide array of applications in the development of vehicle technologies. Although simulation environments, measurement tools and mathematical theories on vehicle dynamics are well established, the methodical link between the experimental test data and validity analysis of the simulation model is still lacking. The developed validation paradigm has a top-down approach to the problem. It is ascertained that vehicle dynamics simulation models can only be validated using test maneuvers although they are aimed for real world maneuvers. Test maneuvers are determined according to the requirements of the real event at the start of the model development project and data handling techniques, validation metrics and criteria are declared for each of the selected maneuvers. If the simulation results satisfy these criteria, then the simulation is deemed ''not invalid''. If the simulation model fails to meet the criteria, the model is deemed invalid, and model iteration should be performed. The results are analyzed to determine if the results indicate a modeling error or a modeling inadequacy; and if a conditional validity in terms of system variables can be defined. Three test cases are used to demonstrate the application of the methodology. The developed methodology successfully identified the shortcomings of the tested simulation model, and defined the limits of application. The tested simulation model is found to be acceptable but valid only in a certain dynamical range. Several insights for the deficiencies of the model are reported in the analysis but the iteration step of the methodology is not demonstrated. Utilizing the proposed methodology will help to achieve more time and cost efficient simulation projects with

Lessons learned related to packaging and transportation

International Nuclear Information System (INIS)

Wallen, C.

1995-01-01

The use of lessons learned as a tool for learning from past experiences is well established, especially by many organizations within the nuclear industry. Every person has, at some time, used the principles of lessons learned to adopt good work practices based on their own experiences or the experiences of others. Lessons learned can also help to avoid the recurrence of adverse practices, which is often an area that most lessons-learned programs tend to focus on. This paper will discuss how lessons learned relate to packaging and transportation issues and events experienced at Department of Energy (DOE) facilities. It will also discuss the role performed by the Office of Nuclear and Facility Safety's Office of Operating Experience Analysis and Feedback in disseminating lessons learned and operating experience feedback to the DOE complex. The central concept of lessons learned is that any organization should be able to learn from its own experiences and events. In addition, organizations should implement methodologies to scan external environments for lessons learned, to analyze and determine the relevance of lessons learned, and to bring about the necessary changes learned from these experiences. With increased concerns toward facility safety, the importance of utilizing the lessons-learned principles and the establishment of lessons-learned programs can not be overstated

The validation of evacuation simulation models through the analysis of behavioural uncertainty

International Nuclear Information System (INIS)

Lovreglio, Ruggiero; Ronchi, Enrico; Borri, Dino

2014-01-01

Both experimental and simulation data on fire evacuation are influenced by a component of uncertainty caused by the impact of the unexplained variance in human behaviour, namely behavioural uncertainty (BU). Evacuation model validation studies should include the study of this type of uncertainty during the comparison of experiments and simulation results. An evacuation model validation procedure is introduced in this paper to study the impact of BU. This methodology is presented through a case study for the comparison between repeated experimental data and simulation results produced by FDS+Evac, an evacuation model for the simulation of human behaviour in fire, which makes use of distribution laws. - Highlights: • Validation of evacuation models is investigated. • Quantitative evaluation of behavioural uncertainty is performed. • A validation procedure is presented through an evacuation case study

Construct validity of the ovine model in endoscopic sinus surgery training.

Science.gov (United States)

Awad, Zaid; Taghi, Ali; Sethukumar, Priya; Tolley, Neil S

2015-03-01

To demonstrate construct validity of the ovine model as a tool for training in endoscopic sinus surgery (ESS). Prospective, cross-sectional evaluation study. Over 18 consecutive months, trainees and experts were evaluated in their ability to perform a range of tasks (based on previous face validation and descriptive studies conducted by the same group) relating to ESS on the sheep-head model. Anonymized randomized video recordings of the above were assessed by two independent and blinded assessors. A validated assessment tool utilizing a five-point Likert scale was employed. Construct validity was calculated by comparing scores across training levels and experts using mean and interquartile range of global and task-specific scores. Subgroup analysis of the intermediate group ascertained previous experience. Nonparametric descriptive statistics were used, and analysis was carried out using SPSS version 21 (IBM, Armonk, NY). Reliability of the assessment tool was confirmed. The model discriminated well between different levels of expertise in global and task-specific scores. A positive correlation was noted between year in training and both global and task-specific scores (P variable, and the number of ESS procedures performed under supervision had the highest impact on performance. This study describes an alternative model for ESS training and assessment. It is also the first to demonstrate construct validity of the sheep-head model for ESS training. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Validating a Technology Enhanced Student-Centered Learning Model

Science.gov (United States)

Kang, Myunghee; Hahn, Jungsun; Chung, Warren

2015-01-01

The Technology Enhanced Student Centered Learning (TESCL) Model in this study presents the core factors that ensure the quality of learning in a technology-supported environment. Although the model was conceptually constructed using a student-centered learning framework and drawing upon previous studies, it should be validated through real-world…

Polarographic validation of chemical speciation models

International Nuclear Information System (INIS)

Duffield, J.R.; Jarratt, J.A.

2001-01-01

It is well established that the chemical speciation of an element in a given matrix, or system of matrices, is of fundamental importance in controlling the transport behaviour of the element. Therefore, to accurately understand and predict the transport of elements and compounds in the environment it is a requirement that both the identities and concentrations of trace element physico-chemical forms can be ascertained. These twin requirements present the analytical scientist with considerable challenges given the labile equilibria, the range of time scales (from nanoseconds to years) and the range of concentrations (ultra-trace to macro) that may be involved. As a result of this analytical variability, chemical equilibrium modelling has become recognised as an important predictive tool in chemical speciation analysis. However, this technique requires firm underpinning by the use of complementary experimental techniques for the validation of the predictions made. The work reported here has been undertaken with the primary aim of investigating possible methodologies that can be used for the validation of chemical speciation models. However, in approaching this aim, direct chemical speciation analyses have been made in their own right. Results will be reported and analysed for the iron(II)/iron(III)-citrate proton system (pH 2 to 10; total [Fe] = 3 mmol dm -3 ; total [citrate 3- ] 10 mmol dm -3 ) in which equilibrium constants have been determined using glass electrode potentiometry, speciation is predicted using the PHREEQE computer code, and validation of predictions is achieved by determination of iron complexation and redox state with associated concentrations. (authors)

Systematic validation of non-equilibrium thermochemical models using Bayesian inference

KAUST Repository

Miki, Kenji

2015-10-01

© 2015 Elsevier Inc. The validation process proposed by Babuška et al. [1] is applied to thermochemical models describing post-shock flow conditions. In this validation approach, experimental data is involved only in the calibration of the models, and the decision process is based on quantities of interest (QoIs) predicted on scenarios that are not necessarily amenable experimentally. Moreover, uncertainties present in the experimental data, as well as those resulting from an incomplete physical model description, are propagated to the QoIs. We investigate four commonly used thermochemical models: a one-temperature model (which assumes thermal equilibrium among all inner modes), and two-temperature models developed by Macheret et al. [2], Marrone and Treanor [3], and Park [4]. Up to 16 uncertain parameters are estimated using Bayesian updating based on the latest absolute volumetric radiance data collected at the Electric Arc Shock Tube (EAST) installed inside the NASA Ames Research Center. Following the solution of the inverse problems, the forward problems are solved in order to predict the radiative heat flux, QoI, and examine the validity of these models. Our results show that all four models are invalid, but for different reasons: the one-temperature model simply fails to reproduce the data while the two-temperature models exhibit unacceptably large uncertainties in the QoI predictions.

Stochastic modeling of oligodendrocyte generation in cell culture: model validation with time-lapse data

Directory of Open Access Journals (Sweden)

Noble Mark

2006-05-01

Full Text Available Abstract Background The purpose of this paper is two-fold. The first objective is to validate the assumptions behind a stochastic model developed earlier by these authors to describe oligodendrocyte generation in cell culture. The second is to generate time-lapse data that may help biomathematicians to build stochastic models of cell proliferation and differentiation under other experimental scenarios. Results Using time-lapse video recording it is possible to follow the individual evolutions of different cells within each clone. This experimental technique is very laborious and cannot replace model-based quantitative inference from clonal data. However, it is unrivalled in validating the structure of a stochastic model intended to describe cell proliferation and differentiation at the clonal level. In this paper, such data are reported and analyzed for oligodendrocyte precursor cells cultured in vitro. Conclusion The results strongly support the validity of the most basic assumptions underpinning the previously proposed model of oligodendrocyte development in cell culture. However, there are some discrepancies; the most important is that the contribution of progenitor cell death to cell kinetics in this experimental system has been underestimated.

Lessons for Teaching Art Criticism.

Science.gov (United States)

Barrett, Terry, Ed.; Clark, Gilbert, Ed.

This collection of lessons is meant to be a practical guide to help teachers engage children in art criticism. The lessons generally follow a similar format. Most suggest an age group but may be modified for use with younger or older students. Several authors suggest variations and extensions for lessons that include studio activities. A broad…

"Frankenstein." [Lesson Plan].

Science.gov (United States)

Simon, Melanie

Based on Mary Shelley's novel "Frankenstein," this lesson plan presents activities designed to help students understand that active readers interpret a novel (its characters, plot, setting, and theme) in different ways; and the great literature can be and has been adapted in many ways over time. The main activity of the lesson involves students…

Late lessons from early warnings: science, precaution, innovation

DEFF Research Database (Denmark)

Hansen, Steffen Foss

2013-01-01

of chemical and technological innovations, and highlight a number of systemic problems. The 'Late Lessons Project' illustrates how damaging and costly the misuse or neglect of the precautionary principle can be, using case studies and a synthesis of the lessons to be learned and applied to maximising...... rather than present specific estimates for these costs. Making the best use of environmental science and modelling helps to make environmental protection and precaution a priority. Producing cost estimates should not be left to economists alone, but should rather be seen as a starting point for a broader...... discussion, featuring also the relevant expertise in health, ecology, demography, modelling and science. Well researched estimates, based on interdisciplinary collaboration, can strengthen some of those scattered and diffuse interests, which during the ordinary processes of policy-making have difficulty...

Phagocytosis: history's lessons.

Science.gov (United States)

Garg, Manish; Chandawarkar, Rajiv Y

2013-01-01

The assimilation of lessons from the past is an essential component of education for scientists of tomorrow. These lessons are not easy to find. History books on science are few and usually highly dramatized and biographies of scientists tend to exaggerate the pomp of scientific discovery. Both underplay the hard and laborious work that is integral to any scientific pursuit. Here we illustrate one such example. A century ago, the Nobel Prize in Medicine was awarded to two scientists: Ilya Metchnikoff, a Russian zoologist, for the discovery ofphagocytosis-a cell-mediated ingestion ofmicrobes; and Paul Ehrlich, a distinguished physician-scientist, for discovering a highly antigen-specific serum-derived antibody-based immune defense. These two diametrically opposing views of the host-pathogen interaction set the stage for a strife that led to seminal advancements in immunology. Mirrored in this journey are important lessons for scientists today--ubiquitously as applicable to modern scientific life as they were a century ago. This commentaryhighlights these lessons--a fitting centenary to a well-deserved recognition.

Importance of Computer Model Validation in Pyroprocessing Technology Development

Energy Technology Data Exchange (ETDEWEB)

Jung, Y. E.; Li, Hui; Yim, M. S. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2014-05-15

In this research, we developed a plan for experimental validation of one of the computer models developed for ER process modeling, i. e., the ERAD code. Several candidate surrogate materials are selected for the experiment considering the chemical and physical properties. Molten salt-based pyroprocessing technology is being examined internationally as an alternative to treat spent nuclear fuel over aqueous technology. The central process in pyroprocessing is electrorefining(ER) which separates uranium from transuranic elements and fission products present in spent nuclear fuel. ER is a widely used process in the minerals industry to purify impure metals. Studies of ER by using actual spent nuclear fuel materials are problematic for both technical and political reasons. Therefore, the initial effort for ER process optimization is made by using computer models. A number of models have been developed for this purpose. But as validation of these models is incomplete and often times problematic, the simulation results from these models are inherently uncertain.

Validation Hydrodynamic Models of Three Topological Models of Secondary Facultative Ponds

OpenAIRE

Aponte-Reyes Alxander

2014-01-01

A methodology was developed to analyze boundary conditions, the size of the mesh and the turbulence of a mathematical model of CFD, which could explain hydrodynamic behavior on facultative stabilization ponds, FSP, built to pilot scale: conventional pond, CP, baffled pond, BP, and baffled-mesh pond, BMP. Models dispersion studies were performed in field for validation, taking samples into and out of the FSP, the information was used to carry out CFD model simulations of the three topologies. ...

Validating a perceptual distraction model in a personal two-zone sound system

DEFF Research Database (Denmark)

Rämö, Jussi; Christensen, Lasse; Bech, Søren

2017-01-01

This paper focuses on validating a perceptual distraction model, which aims to predict user’s perceived distraction caused by audio-on-audio interference, e.g., two competing audio sources within the same listening space. Originally, the distraction model was trained with music-on-music stimuli...... using a simple loudspeaker setup, consisting of only two loudspeakers, one for the target sound source and the other for the interfering sound source. Recently, the model was successfully validated in a complex personal sound-zone system with speech-on-music stimuli. Second round of validations were...... conducted by physically altering the sound-zone system and running a set of new listening experiments utilizing two sound zones within the sound-zone system. Thus, validating the model using a different sound-zone system with both speech-on-music and music-on-speech stimuli sets. Preliminary results show...

Development Instrument’s Learning of Physics Through Scientific Inquiry Model Based Batak Culture to Improve Science Process Skill and Student’s Curiosity

Science.gov (United States)

Nasution, Derlina; Syahreni Harahap, Putri; Harahap, Marabangun

2018-03-01

This research aims to: (1) developed a instrument’s learning (lesson plan, worksheet, student’s book, teacher’s guide book, and instrument test) of physics learning through scientific inquiry learning model based Batak culture to achieve skills improvement process of science students and the students’ curiosity; (2) describe the quality of the result of develop instrument’s learning in high school using scientific inquiry learning model based Batak culture (lesson plan, worksheet, student’s book, teacher’s guide book, and instrument test) to achieve the science process skill improvement of students and the student curiosity. This research is research development. This research developed a instrument’s learning of physics by using a development model that is adapted from the development model Thiagarajan, Semmel, and Semmel. The stages are traversed until retrieved a valid physics instrument’s learning, practical, and effective includes :(1) definition phase, (2) the planning phase, and (3) stages of development. Test performed include expert test/validation testing experts, small groups, and test classes is limited. Test classes are limited to do in SMAN 1 Padang Bolak alternating on a class X MIA. This research resulted in: 1) the learning of physics static fluid material specially for high school grade 10th consisted of (lesson plan, worksheet, student’s book, teacher’s guide book, and instrument test) and quality worthy of use in the learning process; 2) each component of the instrument’s learning meet the criteria have valid learning, practical, and effective way to reach the science process skill improvement and curiosity in students.

Towards criterion validity in classroom language analysis: methodological constraints of metadiscourse and inter-rater agreement

Directory of Open Access Journals (Sweden)

Douglas Altamiro Consolo

2001-02-01

Full Text Available

This paper reports on a process to validate a revised version of a system for coding classroom discourse in foreign language lessons, a context in which the dual role of language (as content and means of communication and the speakers' specific pedagogical aims lead to a certain degree of ambiguity in language analysis. The language used by teachers and students has been extensively studied, and a framework of concepts concerning classroom discourse well-established. Models for coding classroom language need, however, to be revised when they are applied to specific research contexts. The application and revision of an initial framework can lead to the development of earlier models, and to the re-definition of previously established categories of analysis that have to be validated. The procedures followed to validate a coding system are related here as guidelines for conducting research under similar circumstances. The advantages of using instruments that incorporate two types of data, that is, quantitative measures and qualitative information from raters' metadiscourse, are discussed, and it is suggested that such procedure can contribute to the process of validation itself, towards attaining reliability of research results, as well as indicate some constraints of the adopted research methodology.

Accounting for treatment use when validating a prognostic model: a simulation study

Directory of Open Access Journals (Sweden)

Romin Pajouheshnia

2017-07-01

Full Text Available Abstract Background Prognostic models often show poor performance when applied to independent validation data sets. We illustrate how treatment use in a validation set can affect measures of model performance and present the uses and limitations of available analytical methods to account for this using simulated data. Methods We outline how the use of risk-lowering treatments in a validation set can lead to an apparent overestimation of risk by a prognostic model that was developed in a treatment-naïve cohort to make predictions of risk without treatment. Potential methods to correct for the effects of treatment use when testing or validating a prognostic model are discussed from a theoretical perspective.. Subsequently, we assess, in simulated data sets, the impact of excluding treated individuals and the use of inverse probability weighting (IPW on the estimated model discrimination (c-index and calibration (observed:expected ratio and calibration plots in scenarios with different patterns and effects of treatment use. Results Ignoring the use of effective treatments in a validation data set leads to poorer model discrimination and calibration than would be observed in the untreated target population for the model. Excluding treated individuals provided correct estimates of model performance only when treatment was randomly allocated, although this reduced the precision of the estimates. IPW followed by exclusion of the treated individuals provided correct estimates of model performance in data sets where treatment use was either random or moderately associated with an individual's risk when the assumptions of IPW were met, but yielded incorrect estimates in the presence of non-positivity or an unobserved confounder. Conclusions When validating a prognostic model developed to make predictions of risk without treatment, treatment use in the validation set can bias estimates of the performance of the model in future targeted individuals, and

Paleoclimate validation of a numerical climate model

International Nuclear Information System (INIS)

Schelling, F.J.; Church, H.W.; Zak, B.D.; Thompson, S.L.

1994-01-01

An analysis planned to validate regional climate model results for a past climate state at Yucca Mountain, Nevada, against paleoclimate evidence for the period is described. This analysis, which will use the GENESIS model of global climate nested with the RegCM2 regional climate model, is part of a larger study for DOE's Yucca Mountain Site Characterization Project that is evaluating the impacts of long term future climate change on performance of the potential high level nuclear waste repository at Yucca Mountain. The planned analysis and anticipated results are presented

Validation of a phytoremediation computer model

International Nuclear Information System (INIS)

Corapcioglu, M.Y.; Sung, K.; Rhykerd, R.L.; Munster, C.; Drew, M.

1999-01-01

The use of plants to stimulate remediation of contaminated soil is an effective, low-cost cleanup method which can be applied to many different sites. A phytoremediation computer model has been developed to simulate how recalcitrant hydrocarbons interact with plant roots in unsaturated soil. A study was conducted to provide data to validate and calibrate the model. During the study, lysimeters were constructed and filled with soil contaminated with 10 [mg kg -1 ] TNT, PBB and chrysene. Vegetated and unvegetated treatments were conducted in triplicate to obtain data regarding contaminant concentrations in the soil, plant roots, root distribution, microbial activity, plant water use and soil moisture. When given the parameters of time and depth, the model successfully predicted contaminant concentrations under actual field conditions. Other model parameters are currently being evaluated. 15 refs., 2 figs

Implementation of lesson study in physics teaching by group of teachers in Solok West Sumatera

Science.gov (United States)

Yurnetti, Y.

2018-04-01

This article based of collaborative classroom action research with science teachers group or MGMP at Solok West Sumatera; based on their willingness to implementation of lesson study by this group. The study started by discussing some problems according to the implementation of the lesson study, establishing the teaching materials, developing learning tools, defining the model teachers, conducting classroom activities, and reflecting by discussions. The preparation of this study includes some learning material according to temperature and heat; the observation form that led by observer teachers; teachers’s model impression and open questionnaire implementation of lesson study that applied to the students and teachers. This research got some information about the strengths and weaknesses of learning using lesson study from the students involved. To conclude, the implementation of lesson study should be able to support the principle of collaborative in learning. The challenge of this study is how to make a condition to gather some teachers in one school at a certain time because they have the schedule at their own school.

Making Validated Educational Models Central in Preschool Standards.

Science.gov (United States)

Schweinhart, Lawrence J.

This paper presents some ideas to preschool educators and policy makers about how to make validated educational models central in standards for preschool education and care programs that are available to all 3- and 4-year-olds. Defining an educational model as a coherent body of program practices, curriculum content, program and child, and teacher…

Tobacco Use Prevention Education. K-12 Lesson Plans from the Montana Model Curriculum for Health Enhancement.

Science.gov (United States)

Montana State Office of Public Instruction, Helena.

This publication presents K-12 tobacco use prevention lesson plans for schools in the state of Montana. Lessons for students in grades K-6 include: family connections; body tracing; smokeless tobacco; prenatal development; tobacco look-alikes; tobacco chemicals; analyzing tobacco and alcohol ads; tobacco use and the lungs; and a personal health…

Validation of the newborn larynx modeling with aerodynamical experimental data.

Science.gov (United States)

Nicollas, R; Giordano, J; Garrel, R; Medale, M; Caminat, P; Giovanni, A; Ouaknine, M; Triglia, J M

2009-06-01

Many authors have studied adult's larynx modelization, but the mechanisms of newborn's voice production have very rarely been investigated. After validating a numerical model with acoustic data, studies were performed on larynges of human fetuses in order to validate this model with aerodynamical experiments. Anatomical measurements were performed and a simplified numerical model was built using Fluent((R)) with the vocal folds in phonatory position. The results obtained are in good agreement with those obtained by laser Doppler velocimetry (LDV) and high-frame rate particle image velocimetry (HFR-PIV), on an experimental bench with excised human fetus larynges. It appears that computing with first cry physiological parameters leads to a model which is close to those obtained in experiments with real organs.

Material science lesson from the biological photosystem.

Science.gov (United States)

Kim, Younghye; Lee, Jun Ho; Ha, Heonjin; Im, Sang Won; Nam, Ki Tae

2016-01-01

Inspired by photosynthesis, artificial systems for a sustainable energy supply are being designed. Each sequential energy conversion process from light to biomass in natural photosynthesis is a valuable model for an energy collection, transport and conversion system. Notwithstanding the numerous lessons of nature that provide inspiration for new developments, the features of natural photosynthesis need to be reengineered to meet man's demands. This review describes recent strategies toward adapting key lessons from natural photosynthesis to artificial systems. We focus on the underlying material science in photosynthesis that combines photosystems as pivotal functional materials and a range of materials into an integrated system. Finally, a perspective on the future development of photosynthesis mimetic energy systems is proposed.

Validation od computational model ALDERSON/EGSnrc for chest radiography

International Nuclear Information System (INIS)

Muniz, Bianca C.; Santos, André L. dos; Menezes, Claudio J.M.

2017-01-01

To perform dose studies in situations of exposure to radiation, without exposing individuals, the numerical dosimetry uses Computational Exposure Models (ECM). Composed essentially by a radioactive source simulator algorithm, a voxel phantom representing the human anatomy and a Monte Carlo code, the ECMs must be validated to determine the reliability of the physical array representation. The objective of this work is to validate the ALDERSON / EGSnrc MCE by through comparisons between the experimental measurements obtained with the ionization chamber and virtual simulations using Monte Carlo Method to determine the ratio of the input and output radiation dose. Preliminary results of these comparisons showed that the ECM reproduced the results of the experimental measurements performed with the physical phantom with a relative error of less than 10%, validating the use of this model for simulations of chest radiographs and estimates of radiation doses in tissues in the irradiated structures

Predictive validation of an influenza spread model.

Directory of Open Access Journals (Sweden)

Ayaz Hyder

Full Text Available BACKGROUND: Modeling plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation models are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these models remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation model of influenza spread. METHODS AND FINDINGS: We used extensive data on past epidemics to demonstrate the process of predictive validation. This involved generalizing an individual-based model for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998-1999. Next, we used the fitted model and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type. Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our model was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. CONCLUSIONS: Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive validation applied to a current complex simulation model of influenza spread, we provided users of the model (e.g. public-health officials and policy-makers with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other models of communicable infectious diseases to test and potentially improve

Predictive Validation of an Influenza Spread Model

Science.gov (United States)

Hyder, Ayaz; Buckeridge, David L.; Leung, Brian

2013-01-01

Background Modeling plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation models are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these models remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation model of influenza spread. Methods and Findings We used extensive data on past epidemics to demonstrate the process of predictive validation. This involved generalizing an individual-based model for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998–1999). Next, we used the fitted model and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type). Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our model was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. Conclusions Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive validation applied to a current complex simulation model of influenza spread, we provided users of the model (e.g. public-health officials and policy-makers) with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other models of communicable infectious diseases to test and potentially improve their predictive

Pengembangan Paket Nekamedia Matematika Kurikulum 2013 Menggunakan Model Problem Based Learning (Pbl) pada Materi Bangun Ruang Sisi Datar Kelas VIII SMP di Kota Surakarta

OpenAIRE

Anggraini, Putri Nurika; Budiyono, Budiyono; Slamet, Isnandar

2016-01-01

This study was aimed to obtain 2013 Curriculum of mathematics mutlimedia kit using Problem Based Learning (PBL) model in plane geometry lesson of eighth grade junior high school in Surakarta which is considered as a valid, practical, and effective to be applied for learning. Furthermore, the goal was to discover whether the student's achievement of plane geometry lesson using the developed mutlimedia kit is better than using the prior product. The study type was Research and Development (R &a...

Looking beyond general metrics for model comparison - lessons from an international model intercomparison study

Science.gov (United States)

de Boer-Euser, Tanja; Bouaziz, Laurène; De Niel, Jan; Brauer, Claudia; Dewals, Benjamin; Drogue, Gilles; Fenicia, Fabrizio; Grelier, Benjamin; Nossent, Jiri; Pereira, Fernando; Savenije, Hubert; Thirel, Guillaume; Willems, Patrick

2017-01-01

International collaboration between research institutes and universities is a promising way to reach consensus on hydrological model development. Although model comparison studies are very valuable for international cooperation, they do often not lead to very clear new insights regarding the relevance of the modelled processes. We hypothesise that this is partly caused by model complexity and the comparison methods used, which focus too much on a good overall performance instead of focusing on a variety of specific events. In this study, we use an approach that focuses on the evaluation of specific events and characteristics. Eight international research groups calibrated their hourly model on the Ourthe catchment in Belgium and carried out a validation in time for the Ourthe catchment and a validation in space for nested and neighbouring catchments. The same protocol was followed for each model and an ensemble of best-performing parameter sets was selected. Although the models showed similar performances based on general metrics (i.e. the Nash-Sutcliffe efficiency), clear differences could be observed for specific events. We analysed the hydrographs of these specific events and conducted three types of statistical analyses on the entire time series: cumulative discharges, empirical extreme value distribution of the peak flows and flow duration curves for low flows. The results illustrate the relevance of including a very quick flow reservoir preceding the root zone storage to model peaks during low flows and including a slow reservoir in parallel with the fast reservoir to model the recession for the studied catchments. This intercomparison enhanced the understanding of the hydrological functioning of the catchment, in particular for low flows, and enabled to identify present knowledge gaps for other parts of the hydrograph. Above all, it helped to evaluate each model against a set of alternative models.

Model Validation and Verification of Data Mining from the ...

African Journals Online (AJOL)

Michael Horsfall

In this paper, we seek to present a hybrid method for Model Validation and Verification of Data Mining from the ... This model generally states the numerical value of knowledge .... procedures found in the field of software engineering should be ...

How to enhance the future use of energy policy simulation models through ex post validation

International Nuclear Information System (INIS)

Qudrat-Ullah, Hassan

2017-01-01

Although simulation and modeling in general and system dynamics models in particular has long served the energy policy domain, ex post validation of these energy policy models is rarely addressed. In fact, ex post validation is a valuable area of research because it offers modelers a chance to enhance the future use of their simulation models by validating them against the field data. This paper contributes by presenting (i) a system dynamics simulation model, which was developed and used to do a three dimensional, socio-economical and environmental long-term assessment of Pakistan's energy policy in 1999, (ii) a systematic analysis of the 15-years old predictive scenarios produced by a system dynamics simulation model through ex post validation. How did the model predictions compare with the actual data? We report that the ongoing crisis of the electricity sector of Pakistan is unfolding, as the model-based scenarios had projected. - Highlights: • Argues that increased use of energy policy models is dependent on their credibility validation. • An ex post validation process is presented as a solution to build confidence in models. • A unique system dynamics model, MDESRAP, is presented. • The root mean square percentage error and Thiel's inequality statistics are applied. • The dynamic model, MDESRAP, is presented as an ex ante and ex post validated model.

Bayesian Calibration, Validation and Uncertainty Quantification for Predictive Modelling of Tumour Growth: A Tutorial.

Science.gov (United States)

Collis, Joe; Connor, Anthony J; Paczkowski, Marcin; Kannan, Pavitra; Pitt-Francis, Joe; Byrne, Helen M; Hubbard, Matthew E

2017-04-01

In this work, we present a pedagogical tumour growth example, in which we apply calibration and validation techniques to an uncertain, Gompertzian model of tumour spheroid growth. The key contribution of this article is the discussion and application of these methods (that are not commonly employed in the field of cancer modelling) in the context of a simple model, whose deterministic analogue is widely known within the community. In the course of the example, we calibrate the model against experimental data that are subject to measurement errors, and then validate the resulting uncertain model predictions. We then analyse the sensitivity of the model predictions to the underlying measurement model. Finally, we propose an elementary learning approach for tuning a threshold parameter in the validation procedure in order to maximize predictive accuracy of our validated model.

Validation of nuclear models used in space radiation shielding applications

International Nuclear Information System (INIS)

Norman, Ryan B.; Blattnig, Steve R.

2013-01-01

A program of verification and validation has been undertaken to assess the applicability of models to space radiation shielding applications and to track progress as these models are developed over time. In this work, simple validation metrics applicable to testing both model accuracy and consistency with experimental data are developed. The developed metrics treat experimental measurement uncertainty as an interval and are therefore applicable to cases in which epistemic uncertainty dominates the experimental data. To demonstrate the applicability of the metrics, nuclear physics models used by NASA for space radiation shielding applications are compared to an experimental database consisting of over 3600 experimental cross sections. A cumulative uncertainty metric is applied to the question of overall model accuracy, while a metric based on the median uncertainty is used to analyze the models from the perspective of model development by examining subsets of the model parameter space.

Designing an Earthquake-Proof Art Museum: An Arts- and Engineering-Integrated Science Lesson

Science.gov (United States)

Carignan, Anastasia; Hussain, Mahjabeen

2016-01-01

In this practical arts-integrated science and engineering lesson, an inquiry-based approach was adopted to teach a class of fourth graders in a Midwest elementary school about the scientific concepts of plate tectonics and earthquakes. Lessons were prepared following the 5 E instructional model. Next Generation Science Standards (4-ESS3-2) and the…

Development of concept-based physiology lessons for biomedical engineering undergraduate students.

Science.gov (United States)

Nelson, Regina K; Chesler, Naomi C; Strang, Kevin T

2013-06-01

Physiology is a core requirement in the undergraduate biomedical engineering curriculum. In one or two introductory physiology courses, engineering students must learn physiology sufficiently to support learning in their subsequent engineering courses and careers. As preparation for future learning, physiology instruction centered on concepts may help engineering students to further develop their physiology and biomedical engineering knowledge. Following the Backward Design instructional model, a series of seven concept-based lessons was developed for undergraduate engineering students. These online lessons were created as prerequisite physiology training to prepare students to engage in a collaborative engineering challenge activity. This work is presented as an example of how to convert standard, organ system-based physiology content into concept-based content lessons.

Predicting the ungauged basin : Model validation and realism assessment

NARCIS (Netherlands)

Van Emmerik, T.H.M.; Mulder, G.; Eilander, D.; Piet, M.; Savenije, H.H.G.

2015-01-01

The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of

Predicting the ungauged basin: model validation and realism assessment

NARCIS (Netherlands)

van Emmerik, Tim; Mulder, Gert; Eilander, Dirk; Piet, Marijn; Savenije, Hubert

2015-01-01

The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of

Validation of Inhibition Effect in the Cellulose Hydrolysis: a Dynamic Modelling Approach

DEFF Research Database (Denmark)

Morales Rodriguez, Ricardo; Tsai, Chien-Tai; Meyer, Anne S.

2011-01-01

Enzymatic hydrolysis is one of the main steps in the processing of bioethanol from lignocellulosic raw materials. However, complete understanding of the underlying phenomena is still under development. Hence, this study has focused on validation of the inhibition effects in the cellulosic biomass...... for parameter estimation (calibration) and validation purposes. The model predictions using calibrated parameters have shown good agreement with the validation data sets, which provides credibility to the model structure and the parameter values....

Overview of the independent ASTEC V2.0 validation by SARNET partners

International Nuclear Information System (INIS)

Chatelard, Patrick; Arndt, Siegfried; Atanasova, Boryana; Bandini, Giacomino; Bleyer, Alexandre; Brähler, Thimo; Buck, Michael; Kljenak, Ivo; Kujal, Bohumir

2014-01-01

Significant efforts are put into the assessment of the severe accident integral code ASTEC, jointly developed since several years by IRSN and GRS, either through comparison with results of the most important international experiments or through benchmarks with other severe accident simulation codes on plant applications. These efforts are done in first priority by the code developers’ organisations, IRSN and GRS, and also by numerous partners, in particular in the frame of the SARNET European network. The first version of the new series ASTEC V2 had been released in July 2009 to SARNET partners. Two subsequent V2.0 code revisions, including several modelling improvements, have been then released to the same partners, respectively in 2010 and 2011. This paper summarises first the approach of ASTEC validation vs. experiments, along with a description of the validation matrix, and presents then a few examples of applications of the ASTEC V2.0-rev1 version carried out in 2011 by the SARNET users. These calculation examples are selected in a way to cover diverse aspects of severe accident phenomenology, i.e. to cover both in-vessel and ex-vessel processes, in order to provide a good picture of the current ASTEC V2 capabilities. Finally, the main lessons drawn from this joint validation task are summarised, along with an evaluation of the current physical modelling relevance and thus an identification of the ASTEC V2.0 validity domain

A process improvement model for software verification and validation

Science.gov (United States)

Callahan, John; Sabolish, George

1994-01-01

We describe ongoing work at the NASA Independent Verification and Validation (IV&V) Facility to establish a process improvement model for software verification and validation (V&V) organizations. This model, similar to those used by some software development organizations, uses measurement-based techniques to identify problem areas and introduce incremental improvements. We seek to replicate this model for organizations involved in V&V on large-scale software development projects such as EOS and space station. At the IV&V Facility, a university research group and V&V contractors are working together to collect metrics across projects in order to determine the effectiveness of V&V and improve its application. Since V&V processes are intimately tied to development processes, this paper also examines the repercussions for development organizations in large-scale efforts.

Thermal hydraulic model validation for HOR mixed core fuel management

International Nuclear Information System (INIS)

Gibcus, H.P.M.; Vries, J.W. de; Leege, P.F.A. de

1997-01-01

A thermal-hydraulic core management model has been developed for the Hoger Onderwijsreactor (HOR), a 2 MW pool-type university research reactor. The model was adopted for safety analysis purposes in the framework of HEU/LEU core conversion studies. It is applied in the thermal-hydraulic computer code SHORT (Steady-state HOR Thermal-hydraulics) which is presently in use in designing core configurations and for in-core fuel management. An elaborate measurement program was performed for establishing the core hydraulic characteristics for a variety of conditions. The hydraulic data were obtained with a dummy fuel element with special equipment allowing a.o. direct measurement of the true core flow rate. Using these data the thermal-hydraulic model was validated experimentally. The model, experimental tests, and model validation are discussed. (author)

Graduate students teaching elementary earth science through interactive classroom lessons

Science.gov (United States)

Caswell, T. E.; Goudge, T. A.; Jawin, E. R.; Robinson, F.

2014-12-01

Since 2005, graduate students in the Brown University Department of Earth, Environmental, and Planetary Studies have volunteered to teach science to second-grade students at Vartan Gregorian Elementary School in Providence, RI. Initially developed to bring science into classrooms where it was not explicitly included in the curriculum, the graduate student-run program today incorporates the Providence Public Schools Grade 2 science curriculum into weekly, interactive sessions that engage the students in hypothesis-driven science. We will describe the program structure, its integration into the Providence Public Schools curriculum, and 3 example lessons relevant to geology. Lessons are structured to develop the students' ability to share and incorporate others' ideas through written and oral communication. The volunteers explain the basics of the topic and engage the students with introductory questions. The students use this knowledge to develop a hypothesis about the upcoming experiment, recording it in their "Science Notebooks." The students record their observations during the demonstration and discuss the results as a group. The process culminates in the students using their own words to summarize what they learned. Activities of particular interest to educators in geoscience are called "Volcanoes!", "The "Liquid Race," and "Phases of the Moon." The "Volcanoes!" lesson explores explosive vs. effusive volcanism using two simulated volcanoes: one explosive, using Mentos and Diet Coke, and one effusive, using vinegar and baking soda (in model volcanoes that the students construct in teams). In "Liquid Race," which explores viscosity and can be integrated into the "Volcanoes!" lesson, the students connect viscosity to flow speed by racing liquids down a ramp. "Phases of the Moon" teaches the students why the Moon has phases, using ball and stick models, and the terminology of the lunar phases using cream-filled cookies (e.g., Oreos). These lessons, among many others

Release of UF6 from a ruptured model 48Y cylinder at Sequoyah Fuels Corporation Facility: lessons-learned report

International Nuclear Information System (INIS)

1986-08-01

The uranium hexafluoride (UF 6 ) release of January 4, 1986, at the Sequoyah Fuels Corporation facility has been reviewed by a NRC Lessons-Learned Group. A Model 48Y cylinder containing UF 6 ruptured upon being heated after it was grossly overfilled. The UF 6 released upon rupture of the cylinder reacted with airborne moisture to produce hydrofluoric acid (HF) and uranyl fluoride (UO 2 F 2 ). One individual died from exposure to airborne HF and several others were injured. There were no significant immediate effects from exposure to uranyl fluoride. This supplement report contains NRC's response to the recommendations made in NUREG-1198 by the Lessons Learned Group. In developing a response to each of the recommendations, the staff considered actions that should be taken: (1) for the restart of the Sequoyah Fuels Facility; (2) to make near-term improvement; and (3) to improve the regulatory framework

Lesson study in prospective mathematics teacher education: didactic and paradidactic technology in the post-lesson reflection

DEFF Research Database (Denmark)

Rasmussen, Klaus

2016-01-01

This paper presents a detailed analysis of the post-lesson reflection, carried out in the context of eight cases of lesson study conducted by teams of Danish, lower secondaryprospective teachers and their supervisors. The participants, representing different institutions, were all new to the less...... and concern to the whole profession of mathematics teachers and the analysis adds to our insight into the potential of lesson study in prospective education as a meeting place where pertinent actors contribute to the expansion and dissemination of shared professional knowledge......This paper presents a detailed analysis of the post-lesson reflection, carried out in the context of eight cases of lesson study conducted by teams of Danish, lower secondaryprospective teachers and their supervisors. The participants, representing different institutions, were all new to the lesson...... study format. Nevertheless, it is demonstrated how their interaction shape the development of discourse about mathematical learning. The anthropological theory of the didactic is employed as the theoretical approach to analyse the mathematical and primarily didactical praxeologies developed...

Validated TRNSYS Model for Solar Assisted Space Heating System

International Nuclear Information System (INIS)

Abdalla, Nedal

2014-01-01

The present study involves a validated TRNSYS model for solar assisted space heating system as applied to a residential building in Jordan using new detailed radiation models of the TRNSYS 17.1 and geometric building model Trnsys3d for the Google SketchUp 3D drawing program. The annual heating load for a building (Solar House) which is located at the Royal ScientiFIc Society (RS5) in Jordan is estimated under climatological conditions of Amman. The aim of this Paper is to compare measured thermal performance of the Solar House with that modeled using TRNSYS. The results showed that the annual measured space heating load for the building was 6,188 kWh while the heati.ng load for the modeled building was 6,391 kWh. Moreover, the measured solar fraction for the solar system was 50% while the modeled solar fraction was 55%. A comparison of modeled and measured data resulted in percentage mean absolute errors for solar energy for space heating, auxiliary heating and solar fraction of 13%, 7% and 10%, respectively. The validated model will be useful for long-term performance simulation under different weather and operating conditions.(author)

Validation of statistical models for creep rupture by parametric analysis

Energy Technology Data Exchange (ETDEWEB)

Bolton, J., E-mail: john.bolton@uwclub.net [65, Fisher Ave., Rugby, Warks CV22 5HW (United Kingdom)

2012-01-15

Statistical analysis is an efficient method for the optimisation of any candidate mathematical model of creep rupture data, and for the comparative ranking of competing models. However, when a series of candidate models has been examined and the best of the series has been identified, there is no statistical criterion to determine whether a yet more accurate model might be devised. Hence there remains some uncertainty that the best of any series examined is sufficiently accurate to be considered reliable as a basis for extrapolation. This paper proposes that models should be validated primarily by parametric graphical comparison to rupture data and rupture gradient data. It proposes that no mathematical model should be considered reliable for extrapolation unless the visible divergence between model and data is so small as to leave no apparent scope for further reduction. This study is based on the data for a 12% Cr alloy steel used in BS PD6605:1998 to exemplify its recommended statistical analysis procedure. The models considered in this paper include a) a relatively simple model, b) the PD6605 recommended model and c) a more accurate model of somewhat greater complexity. - Highlights: Black-Right-Pointing-Pointer The paper discusses the validation of creep rupture models derived from statistical analysis. Black-Right-Pointing-Pointer It demonstrates that models can be satisfactorily validated by a visual-graphic comparison of models to data. Black-Right-Pointing-Pointer The method proposed utilises test data both as conventional rupture stress and as rupture stress gradient. Black-Right-Pointing-Pointer The approach is shown to be more reliable than a well-established and widely used method (BS PD6605).

Validation of a two-fluid model used for the simulation of dense fluidized beds; Validation d`un modele a deux fluides applique a la simulation des lits fluidises denses

Energy Technology Data Exchange (ETDEWEB)

Boelle, A.

1997-02-17

A two-fluid model applied to the simulation of gas-solid dense fluidized beds is validated on micro scale and on macro scale. Phase coupling is carried out in the momentum and energy transport equation of both phases. The modeling is built on the kinetic theory of granular media in which the gas action has been taken into account in order to get correct expressions of transport coefficients. A description of hydrodynamic interactions between particles in high Stokes number flow is also incorporated in the model. The micro scale validation uses Lagrangian numerical simulations viewed as numerical experiments. The first validation case refers to a gas particle simple shear flow. It allows to validate the competition between two dissipation mechanisms: drag and particle collisions. The second validation case is concerted with sedimenting particles in high Stokes number flow. It allows to validate our approach of hydrodynamic interactions. This last case had led us to develop an original Lagrangian simulation with a two-way coupling between the fluid and the particles. The macro scale validation uses the results of Eulerian simulations of dense fluidized bed. Bed height, particles circulation and spontaneous created bubbles characteristics are studied and compared to experimental measurement, both looking at physical and numerical parameters. (author) 159 refs.

Basic Modelling principles and Validation of Software for Prediction of Collision Damage

DEFF Research Database (Denmark)

Simonsen, Bo Cerup

2000-01-01

This report describes basic modelling principles, the theoretical background and validation examples for the collision damage prediction module in the ISESO stand-alone software.......This report describes basic modelling principles, the theoretical background and validation examples for the collision damage prediction module in the ISESO stand-alone software....

Gap Conductance model Validation in the TASS/SMR-S code using MARS code

International Nuclear Information System (INIS)

Ahn, Sang Jun; Yang, Soo Hyung; Chung, Young Jong; Lee, Won Jae

2010-01-01

Korea Atomic Energy Research Institute (KAERI) has been developing the TASS/SMR-S (Transient and Setpoint Simulation/Small and Medium Reactor) code, which is a thermal hydraulic code for the safety analysis of the advanced integral reactor. An appropriate work to validate the applicability of the thermal hydraulic models within the code should be demanded. Among the models, the gap conductance model which is describes the thermal gap conductivity between fuel and cladding was validated through the comparison with MARS code. The validation of the gap conductance model was performed by evaluating the variation of the gap temperature and gap width as the changed with the power fraction. In this paper, a brief description of the gap conductance model in the TASS/SMR-S code is presented. In addition, calculated results to validate the gap conductance model are demonstrated by comparing with the results of the MARS code with the test case

Arts Impact: Lessons from ArtsBridge

Science.gov (United States)

Shimshon-Santo, Amy R.

2010-01-01

Arts Impact summarizes lessons learned at the ArtsBridge Program. It is informed by in-depth participant observation, logic modeling, and quantitative evaluation of program impact on K-12 students in inner city schools and arts students at the University of California Los Angeles over a two year period. The case study frames its analysis through a…

Assessment model validity document FARF31

International Nuclear Information System (INIS)

Elert, Mark; Gylling Bjoern; Lindgren, Maria

2004-08-01

The prime goal of model validation is to build confidence in the model concept and that the model is fit for its intended purpose. In other words: Does the model predict transport in fractured rock adequately to be used in repository performance assessments. Are the results reasonable for the type of modelling tasks the model is designed for. Commonly, in performance assessments a large number of realisations of flow and transport is made to cover the associated uncertainties. Thus, the flow and transport including radioactive chain decay are preferably calculated in the same model framework. A rather sophisticated concept is necessary to be able to model flow and radionuclide transport in the near field and far field of a deep repository, also including radioactive chain decay. In order to avoid excessively long computational times there is a need for well-based simplifications. For this reason, the far field code FARF31 is made relatively simple, and calculates transport by using averaged entities to represent the most important processes. FARF31 has been shown to be suitable for the performance assessments within the SKB studies, e.g. SR 97. Among the advantages are that it is a fast, simple and robust code, which enables handling of many realisations with wide spread in parameters in combination with chain decay of radionuclides. Being a component in the model chain PROPER, it is easy to assign statistical distributions to the input parameters. Due to the formulation of the advection-dispersion equation in FARF31 it is possible to perform the groundwater flow calculations separately.The basis for the modelling is a stream tube, i.e. a volume of rock including fractures with flowing water, with the walls of the imaginary stream tube defined by streamlines. The transport within the stream tube is described using a dual porosity continuum approach, where it is assumed that rock can be divided into two distinct domains with different types of porosity

Learning lessons from operational research in infectious diseases: can the same model be used for noncommunicable diseases in developing countries?

Directory of Open Access Journals (Sweden)

Bosu WK

2014-12-01

Full Text Available William K Bosu Department of Epidemics and Disease Control, West African Health Organisation, Bobo-Dioulasso, Burkina Faso Abstract: About three-quarters of global deaths from noncommunicable diseases (NCDs occur in developing countries. Nearly a third of these deaths occur before the age of 60 years. These deaths are projected to increase, fueled by such factors as urbanization, nutrition transition, lifestyle changes, and aging. Despite this burden, there is a paucity of research on NCDs, due to the higher priority given to infectious disease research. Less than 10% of research on cardiovascular diseases comes from developing countries. This paper assesses what lessons from operational research on infectious diseases could be applied to NCDs. The lessons are drawn from the priority setting for research, integration of research into programs and routine service delivery, the use of routine data, rapid-assessment survey methods, modeling, chemoprophylaxis, and the translational process of findings into policy and practice. With the lines between infectious diseases and NCDs becoming blurred, it is justifiable to integrate the programs for the two disease groups wherever possible, eg, screening for diabetes in tuberculosis. Applying these lessons will require increased political will, research capacity, ownership, use of local expertise, and research funding. Keywords: infectious diseases, noncommunicable diseases, operational research, developing countries, integration

"Lesson Study" as Professional Culture in Japanese Schools: An Historical Perspective on Elementary Classroom Practices

Science.gov (United States)

Arani, Mohammad Reza Sarkar; Keisuke, Fukaya; Lassegard, James P.

2010-01-01

This research examines "lesson study" as a traditional model of creating professional knowledge in schools. "Lesson study," typically defined as teachers' classroom based collaborative research, has a long history in Japan as a shared professional culture with potential for enhancing learning, enriching classroom activities and…

Validation Assessment of a Glass-to-Metal Seal Finite-Element Model

Energy Technology Data Exchange (ETDEWEB)

Jamison, Ryan Dale [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Buchheit, Thomas E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Emery, John M [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Romero, Vicente J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stavig, Mark E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Newton, Clay S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brown, Arthur [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

Sealing glasses are ubiquitous in high pressure and temperature engineering applications, such as hermetic feed-through electrical connectors. A common connector technology are glass-to-metal seals where a metal shell compresses a sealing glass to create a hermetic seal. Though finite-element analysis has been used to understand and design glass-to-metal seals for many years, there has been little validation of these models. An indentation technique was employed to measure the residual stress on the surface of a simple glass-to-metal seal. Recently developed rate- dependent material models of both Schott 8061 and 304L VAR stainless steel have been applied to a finite-element model of the simple glass-to-metal seal. Model predictions of residual stress based on the evolution of material models are shown. These model predictions are compared to measured data. Validity of the finite- element predictions is discussed. It will be shown that the finite-element model of the glass-to-metal seal accurately predicts the mean residual stress in the glass near the glass-to-metal interface and is valid for this quantity of interest.

Validation of an employee satisfaction model: A structural equation model approach

OpenAIRE

Ophillia Ledimo; Nico Martins

2015-01-01

The purpose of this study was to validate an employee satisfaction model and to determine the relationships between the different dimensions of the concept, using the structural equation modelling approach (SEM). A cross-sectional quantitative survey design was used to collect data from a random sample of (n=759) permanent employees of a parastatal organisation. Data was collected using the Employee Satisfaction Survey (ESS) to measure employee satisfaction dimensions. Following the steps of ...

Assessment model validity document - HYDRASTAR. A stochastic continuum program for groundwater flow

Energy Technology Data Exchange (ETDEWEB)

Gylling, B. [Kemakta Konsult AB, Stockholm (Sweden); Eriksson, Lars [Equa Simulation AB, Sundbyberg (Sweden)

2001-12-01

The prevailing document addresses validation of the stochastic continuum model HYDRASTAR designed for Monte Carlo simulations of groundwater flow in fractured rocks. Here, validation is defined as a process to demonstrate that a model concept is fit for its purpose. Preferably, the validation is carried out by comparison of model predictions with independent field observations and experimental measurements. In addition, other sources can also be used to confirm that the model concept gives acceptable results. One method is to compare results with the ones achieved using other model concepts for the same set of input data. Another method is to compare model results with analytical solutions. The model concept HYDRASTAR has been used in several studies including performance assessments of hypothetical repositories for spent nuclear fuel. In the performance assessments, the main tasks for HYDRASTAR have been to calculate groundwater travel time distributions, repository flux distributions, path lines and their exit locations. The results have then been used by other model concepts to calculate the near field release and far field transport. The aim and framework for the validation process includes describing the applicability of the model concept for its purpose in order to build confidence in the concept. Preferably, this is made by comparisons of simulation results with the corresponding field experiments or field measurements. Here, two comparisons with experimental results are reported. In both cases the agreement was reasonably fair. In the broader and more general context of the validation process, HYDRASTAR results have been compared with other models and analytical solutions. Commonly, the approximation calculations agree well with the medians of model ensemble results. Additional indications that HYDRASTAR is suitable for its purpose were obtained from the comparisons with results from other model concepts. Several verification studies have been made for

Evaluation factors for verification and validation of low-level waste disposal site models

International Nuclear Information System (INIS)

Moran, M.S.; Mezga, L.J.

1982-01-01

The purpose of this paper is to identify general evaluation factors to be used to verify and validate LLW disposal site performance models in order to assess their site-specific applicability and to determine their accuracy and sensitivity. It is intended that the information contained in this paper be employed by model users involved with LLW site performance model verification and validation. It should not be construed as providing protocols, but rather as providing a framework for the preparation of specific protocols or procedures. A brief description of each evaluation factor is provided. The factors have been categorized according to recommended use during either the model verification or the model validation process. The general responsibilities of the developer and user are provided. In many cases it is difficult to separate the responsibilities of the developer and user, but the user is ultimately accountable for both verification and validation processes. 4 refs

Validation of elk resource selection models with spatially independent data

Science.gov (United States)

Priscilla K. Coe; Bruce K. Johnson; Michael J. Wisdom; John G. Cook; Marty Vavra; Ryan M. Nielson

2011-01-01

Knowledge of how landscape features affect wildlife resource use is essential for informed management. Resource selection functions often are used to make and validate predictions about landscape use; however, resource selection functions are rarely validated with data from landscapes independent of those from which the models were built. This problem has severely...

Nonparametric model validations for hidden Markov models with applications in financial econometrics.

Science.gov (United States)

Zhao, Zhibiao

2011-06-01

We address the nonparametric model validation problem for hidden Markov models with partially observable variables and hidden states. We achieve this goal by constructing a nonparametric simultaneous confidence envelope for transition density function of the observable variables and checking whether the parametric density estimate is contained within such an envelope. Our specification test procedure is motivated by a functional connection between the transition density of the observable variables and the Markov transition kernel of the hidden states. Our approach is applicable for continuous time diffusion models, stochastic volatility models, nonlinear time series models, and models with market microstructure noise.

Validity of information security policy models

Directory of Open Access Journals (Sweden)

Joshua Onome Imoniana

Full Text Available Validity is concerned with establishing evidence for the use of a method to be used with a particular set of population. Thus, when we address the issue of application of security policy models, we are concerned with the implementation of a certain policy, taking into consideration the standards required, through attribution of scores to every item in the research instrument. En today's globalized economic scenarios, the implementation of information security policy, in an information technology environment, is a condition sine qua non for the strategic management process of any organization. Regarding this topic, various studies present evidences that, the responsibility for maintaining a policy rests primarily with the Chief Security Officer. The Chief Security Officer, in doing so, strives to enhance the updating of technologies, in order to meet all-inclusive business continuity planning policies. Therefore, for such policy to be effective, it has to be entirely embraced by the Chief Executive Officer. This study was developed with the purpose of validating specific theoretical models, whose designs were based on literature review, by sampling 10 of the Automobile Industries located in the ABC region of Metropolitan São Paulo City. This sampling was based on the representativeness of such industries, particularly with regards to each one's implementation of information technology in the region. The current study concludes, presenting evidence of the discriminating validity of four key dimensions of the security policy, being such: the Physical Security, the Logical Access Security, the Administrative Security, and the Legal & Environmental Security. On analyzing the Alpha of Crombach structure of these security items, results not only attest that the capacity of those industries to implement security policies is indisputable, but also, the items involved, homogeneously correlate to each other.

Validation and selection of ODE based systems biology models: how to arrive at more reliable decisions.

Science.gov (United States)

Hasdemir, Dicle; Hoefsloot, Huub C J; Smilde, Age K

2015-07-08

Most ordinary differential equation (ODE) based modeling studies in systems biology involve a hold-out validation step for model validation. In this framework a pre-determined part of the data is used as validation data and, therefore it is not used for estimating the parameters of the model. The model is assumed to be validated if the model predictions on the validation dataset show good agreement with the data. Model selection between alternative model structures can also be performed in the same setting, based on the predictive power of the model structures on the validation dataset. However, drawbacks associated with this approach are usually under-estimated. We have carried out simulations by using a recently published High Osmolarity Glycerol (HOG) pathway from S.cerevisiae to demonstrate these drawbacks. We have shown that it is very important how the data is partitioned and which part of the data is used for validation purposes. The hold-out validation strategy leads to biased conclusions, since it can lead to different validation and selection decisions when different partitioning schemes are used. Furthermore, finding sensible partitioning schemes that would lead to reliable decisions are heavily dependent on the biology and unknown model parameters which turns the problem into a paradox. This brings the need for alternative validation approaches that offer flexible partitioning of the data. For this purpose, we have introduced a stratified random cross-validation (SRCV) approach that successfully overcomes these limitations. SRCV leads to more stable decisions for both validation and selection which are not biased by underlying biological phenomena. Furthermore, it is less dependent on the specific noise realization in the data. Therefore, it proves to be a promising alternative to the standard hold-out validation strategy.

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.

Cross validation for the classical model of structured expert judgment

International Nuclear Information System (INIS)

Colson, Abigail R.; Cooke, Roger M.

2017-01-01

We update the 2008 TU Delft structured expert judgment database with data from 33 professionally contracted Classical Model studies conducted between 2006 and March 2015 to evaluate its performance relative to other expert aggregation models. We briefly review alternative mathematical aggregation schemes, including harmonic weighting, before focusing on linear pooling of expert judgments with equal weights and performance-based weights. Performance weighting outperforms equal weighting in all but 1 of the 33 studies in-sample. True out-of-sample validation is rarely possible for Classical Model studies, and cross validation techniques that split calibration questions into a training and test set are used instead. Performance weighting incurs an “out-of-sample penalty” and its statistical accuracy out-of-sample is lower than that of equal weighting. However, as a function of training set size, the statistical accuracy of performance-based combinations reaches 75% of the equal weight value when the training set includes 80% of calibration variables. At this point the training set is sufficiently powerful to resolve differences in individual expert performance. The information of performance-based combinations is double that of equal weighting when the training set is at least 50% of the set of calibration variables. Previous out-of-sample validation work used a Total Out-of-Sample Validity Index based on all splits of the calibration questions into training and test subsets, which is expensive to compute and includes small training sets of dubious value. As an alternative, we propose an Out-of-Sample Validity Index based on averaging the product of statistical accuracy and information over all training sets sized at 80% of the calibration set. Performance weighting outperforms equal weighting on this Out-of-Sample Validity Index in 26 of the 33 post-2006 studies; the probability of 26 or more successes on 33 trials if there were no difference between performance

Job task analysis: lessons learned from application in course development

International Nuclear Information System (INIS)

Meredith, J.B.

1985-01-01

Those at Public Service Electric and Gas Company are committed to a systematic approach to training known as Instructional System Design. Our performance-based training emphasizes the ISD process to have trainees do or perform the task whenever and wherever it is possible for the jobs for which they are being trained. Included is a brief description of our process for conducting and validating job analyses. The major thrust of this paper is primarily on the lessons that we have learned in the design and development of training programs based upon job analysis results

Verifying and Validating Simulation Models

Energy Technology Data Exchange (ETDEWEB)

Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-02-23

This presentation is a high-level discussion of the Verification and Validation (V&V) of computational models. Definitions of V&V are given to emphasize that “validation” is never performed in a vacuum; it accounts, instead, for the current state-of-knowledge in the discipline considered. In particular comparisons between physical measurements and numerical predictions should account for their respective sources of uncertainty. The differences between error (bias), aleatoric uncertainty (randomness) and epistemic uncertainty (ignorance, lack-of- knowledge) are briefly discussed. Four types of uncertainty in physics and engineering are discussed: 1) experimental variability, 2) variability and randomness, 3) numerical uncertainty and 4) model-form uncertainty. Statistical sampling methods are available to propagate, and analyze, variability and randomness. Numerical uncertainty originates from the truncation error introduced by the discretization of partial differential equations in time and space. Model-form uncertainty is introduced by assumptions often formulated to render a complex problem more tractable and amenable to modeling and simulation. The discussion concludes with high-level guidance to assess the “credibility” of numerical simulations, which stems from the level of rigor with which these various sources of uncertainty are assessed and quantified.

Validation of a multi-objective, predictive urban traffic model

NARCIS (Netherlands)

Wilmink, I.R.; Haak, P. van den; Woldeab, Z.; Vreeswijk, J.

2013-01-01

This paper describes the results of the verification and validation of the ecoStrategic Model, which was developed, implemented and tested in the eCoMove project. The model uses real-time and historical traffic information to determine the current, predicted and desired state of traffic in a

The individual teacher in lesson study collaboration

DEFF Research Database (Denmark)

Skott, Charlotte Krog; Møller, Hanne

2017-01-01

used in lesson study research. Design/methodology/approach The authors use collective case studies. By being participant observers the authors provide detailed descriptions of two selected teachers’ lived experiences of lesson study collaboration. In addition to gain first-hand insights, the authors...... in the participation of each of the two teachers during a two-year lesson study project. By comparing these shifts the authors identify significant conditions for their individual learning. Research limitations/implications Although the study is small scale, both the insights into the different ways in which teachers...... participated and the theoretical insights might be valuable for other lesson study research approaches. Practical implications This paper provides valuable insights into conditions that might influence teachers’ participation in lesson study activities, especially in cultures with little experience of lesson...

Animal models of binge drinking, current challenges to improve face validity.

Science.gov (United States)

Jeanblanc, Jérôme; Rolland, Benjamin; Gierski, Fabien; Martinetti, Margaret P; Naassila, Mickael

2018-05-05

Binge drinking (BD), i.e., consuming a large amount of alcohol in a short period of time, is an increasing public health issue. Though no clear definition has been adopted worldwide the speed of drinking seems to be a keystone of this behavior. Developing relevant animal models of BD is a priority for gaining a better characterization of the neurobiological and psychobiological mechanisms underlying this dangerous and harmful behavior. Until recently, preclinical research on BD has been conducted mostly using forced administration of alcohol, but more recent studies used scheduled access to alcohol, to model more voluntary excessive intakes, and to achieve signs of intoxications that mimic the human behavior. The main challenges for future research are discussed regarding the need of good face validity, construct validity and predictive validity of animal models of BD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Field validation of the contaminant transport model, FEMA

International Nuclear Information System (INIS)

Wong, K.-F.V.

1986-01-01

The work describes the validation with field data of a finite element model of material transport through aquifers (FEMA). Field data from the Idaho Chemical Processing Plant, Idaho, USA and from the 58th Street landfill in Miami, Florida, USA are used. In both cases the model was first calibrated and then integrated over a span of eight years to check on the predictive capability of the model. Both predictive runs gave results that matched well with available data. (author)

Validation of a regional distribution model in environmental risk assessment of substances

Energy Technology Data Exchange (ETDEWEB)

Berding, V.

2000-06-26

The regional distribution model SimpleBox proposed in the TGD (Technical Guidance Document) and implemented in the EUSES software (European Union System for the Evaluation of Substances) was validated. The aim of this investigation was to determine the applicability and weaknesses of the model and to make proposals for improvement. The validation was performed using the scheme set up by SCHWARTZ (2000) of which the main aspects are the division into internal and external validation, i.e. into generic and task-specific properties of the model. These two validation parts contain the scrutiny of theory, sensitivity analyses, comparison of predicted environmental concentrations with measured ones by means of scenario analyses, uncertainty analyses and comparison with alternative models. Generally, the model employed is a reasonable compromise between complexity and simplification. Simpler models are applicable, too, but in many cases the results can deviate considerably from the measured values. For the sewage treatment model, it could be shown that its influence on the predicted concentration is very low and a much simpler model fulfils its purpose in a similar way. It is proposed to improve the model in several ways, e.g. by including the pH/pK-correction for dissociating substances or by alternative estimations functions for partition coefficients. But the main focus for future improvements should be on the amelioration of release estimations and substance characteristics as degradation rates and partition coefficients.

External validation of EPIWIN biodegradation models.

Science.gov (United States)

Posthumus, R; Traas, T P; Peijnenburg, W J G M; Hulzebos, E M

2005-01-01

The BIOWIN biodegradation models were evaluated for their suitability for regulatory purposes. BIOWIN includes the linear and non-linear BIODEG and MITI models for estimating the probability of rapid aerobic biodegradation and an expert survey model for primary and ultimate biodegradation estimation. Experimental biodegradation data for 110 newly notified substances were compared with the estimations of the different models. The models were applied separately and in combinations to determine which model(s) showed the best performance. The results of this study were compared with the results of other validation studies and other biodegradation models. The BIOWIN models predict not-readily biodegradable substances with high accuracy in contrast to ready biodegradability. In view of the high environmental concern of persistent chemicals and in view of the large number of not-readily biodegradable chemicals compared to the readily ones, a model is preferred that gives a minimum of false positives without a corresponding high percentage false negatives. A combination of the BIOWIN models (BIOWIN2 or BIOWIN6) showed the highest predictive value for not-readily biodegradability. However, the highest score for overall predictivity with lowest percentage false predictions was achieved by applying BIOWIN3 (pass level 2.75) and BIOWIN6.

Validation of the STAFF-5 computer model

International Nuclear Information System (INIS)

Fletcher, J.F.; Fields, S.R.

1981-04-01

STAFF-5 is a dynamic heat-transfer-fluid-flow stress model designed for computerized prediction of the temperature-stress performance of spent LWR fuel assemblies under storage/disposal conditions. Validation of the temperature calculating abilities of this model was performed by comparing temperature calculations under specified conditions to experimental data from the Engine Maintenance and Dissassembly (EMAD) Fuel Temperature Test Facility and to calculations performed by Battelle Pacific Northwest Laboratory (PNL) using the HYDRA-1 model. The comparisons confirmed the ability of STAFF-5 to calculate representative fuel temperatures over a considerable range of conditions, as a first step in the evaluation and prediction of fuel temperature-stress performance

The Validation of a Beta-Binomial Model for Overdispersed Binomial Data.

Science.gov (United States)

Kim, Jongphil; Lee, Ji-Hyun

2017-01-01

The beta-binomial model has been widely used as an analytically tractable alternative that captures the overdispersion of an intra-correlated, binomial random variable, X . However, the model validation for X has been rarely investigated. As a beta-binomial mass function takes on a few different shapes, the model validation is examined for each of the classified shapes in this paper. Further, the mean square error (MSE) is illustrated for each shape by the maximum likelihood estimator (MLE) based on a beta-binomial model approach and the method of moments estimator (MME) in order to gauge when and how much the MLE is biased.

What Happens at the Lesson Start?

Science.gov (United States)

Saloviita, Timo

2016-01-01

Transitional periods, such as lesson starts, are necessary steps from one activity to another, but they also compete with time for actual learning. The aim of the present study was to replicate a previous pilot study on lesson starts and explore possible disturbances. In total, 130 lesson starts in Finnish basic education in grades 1-9 were…

Lessons learned on utilizing the SEI/CMM in the federal government work for others environment

Energy Technology Data Exchange (ETDEWEB)

Stewart, A.

1997-11-01

This report contains viewgraphs on lessons learned on utilizing the Software Engineering Institute Capability Maturity Model in the federal government work for others environment. These viewgraphs outline: data systems research and development; what is the SEI/CMM; Data Systems Research and Development process improvement approach; accomplishments; and lessons learned.

Bayesian leave-one-out cross-validation approximations for Gaussian latent variable models

DEFF Research Database (Denmark)

Vehtari, Aki; Mononen, Tommi; Tolvanen, Ville

2016-01-01

The future predictive performance of a Bayesian model can be estimated using Bayesian cross-validation. In this article, we consider Gaussian latent variable models where the integration over the latent values is approximated using the Laplace method or expectation propagation (EP). We study...... the properties of several Bayesian leave-one-out (LOO) cross-validation approximations that in most cases can be computed with a small additional cost after forming the posterior approximation given the full data. Our main objective is to assess the accuracy of the approximative LOO cross-validation estimators...

Developing a PLC-friendly state machine model: lessons learned

Science.gov (United States)

Pessemier, Wim; Deconinck, Geert; Raskin, Gert; Saey, Philippe; Van Winckel, Hans

2014-07-01

Modern Programmable Logic Controllers (PLCs) have become an attractive platform for controlling real-time aspects of astronomical telescopes and instruments due to their increased versatility, performance and standardization. Likewise, vendor-neutral middleware technologies such as OPC Unified Architecture (OPC UA) have recently demonstrated that they can greatly facilitate the integration of these industrial platforms into the overall control system. Many practical questions arise, however, when building multi-tiered control systems that consist of PLCs for low level control, and conventional software and platforms for higher level control. How should the PLC software be structured, so that it can rely on well-known programming paradigms on the one hand, and be mapped to a well-organized OPC UA interface on the other hand? Which programming languages of the IEC 61131-3 standard closely match the problem domains of the abstraction levels within this structure? How can the recent additions to the standard (such as the support for namespaces and object-oriented extensions) facilitate a model based development approach? To what degree can our applications already take advantage of the more advanced parts of the OPC UA standard, such as the high expressiveness of the semantic modeling language that it defines, or the support for events, aggregation of data, automatic discovery, ... ? What are the timing and concurrency problems to be expected for the higher level tiers of the control system due to the cyclic execution of control and communication tasks by the PLCs? We try to answer these questions by demonstrating a semantic state machine model that can readily be implemented using IEC 61131 and OPC UA. One that does not aim to capture all possible states of a system, but rather one that attempts to organize the course-grained structure and behaviour of a system. In this paper we focus on the intricacies of this seemingly simple task, and on the lessons that we

Recent validation studies for two NRPB environmental transfer models

International Nuclear Information System (INIS)

Brown, J.; Simmonds, J.R.

1991-01-01

The National Radiological Protection Board (NRPB) developed a dynamic model for the transfer of radionuclides through terrestrial food chains some years ago. This model, now called FARMLAND, predicts both instantaneous and time integrals of concentration of radionuclides in a variety of foods. The model can be used to assess the consequences of both accidental and routine releases of radioactivity to the environment; and results can be obtained as a function of time. A number of validation studies have been carried out on FARMLAND. In these the model predictions have been compared with a variety of sets of environmental measurement data. Some of these studies will be outlined in the paper. A model to predict external radiation exposure from radioactivity deposited on different surfaces in the environment has also been developed at NRPB. This model, called EXPURT (EXPosure from Urban Radionuclide Transfer), can be used to predict radiation doses as a function of time following deposition in a variety of environments, ranging from rural to inner-city areas. This paper outlines validation studies and future extensions to be carried out on EXPURT. (12 refs., 4 figs.)

Lesson study i Danmark?

DEFF Research Database (Denmark)

Mogensen, Arne

2009-01-01

Der beskrives et japansk lesson study forløb, og det diskuteres i hvilket omfang, de gode japanske erfaringer kan overføres til dansk matematikundervisning.......Der beskrives et japansk lesson study forløb, og det diskuteres i hvilket omfang, de gode japanske erfaringer kan overføres til dansk matematikundervisning....

NRPB models for calculating the transfer of radionuclides through the environment. Verification and validation

International Nuclear Information System (INIS)

Attwood, C.; Barraclough, I.; Brown, J.

1998-06-01

There is a wide range of models available at NRPB to predict the transfer of radionuclides through the environment. Such models form an essential part of assessments of the radiological impact of releases of radionuclides into the environment. These models cover: the atmosphere; the aquatic environment; the geosphere; the terrestrial environment including foodchains. It is important that the models used for radiological impact assessments are robust, reliable and suitable for the assessment being undertaken. During model development it is, therefore, important that the model is both verified and validated. Verification of a model involves ensuring that it has been implemented correctly, while validation consists of demonstrating that the model is an adequate representation of the real environment. The extent to which a model can be verified depends on its complexity and whether similar models exist. For relatively simple models verification is straightforward, but for more complex models verification has to form part of the development, coding and testing of the model within quality assurance procedures. Validation of models should ideally consist of comparisons between the results of the models and experimental or environmental measurement data that were not used to develop the model. This is more straightforward for some models than for others depending on the quantity and type of data available. Validation becomes increasingly difficult for models which are intended to predict environmental transfer at long times or at great distances. It is, therefore, necessary to adopt qualitative validation techniques to ensure that the model is an adequate representation of the real environment. This report summarises the models used at NRPB to predict the transfer of radionuclides through the environment as part of a radiological impact assessment. It outlines the work carried out to verify and validate the models. The majority of these models are not currently available

Validation by simulation of a clinical trial model using the standardized mean and variance criteria.

Science.gov (United States)

Abbas, Ismail; Rovira, Joan; Casanovas, Josep

2006-12-01

To develop and validate a model of a clinical trial that evaluates the changes in cholesterol level as a surrogate marker for lipodystrophy in HIV subjects under alternative antiretroviral regimes, i.e., treatment with Protease Inhibitors vs. a combination of nevirapine and other antiretroviral drugs. Five simulation models were developed based on different assumptions, on treatment variability and pattern of cholesterol reduction over time. The last recorded cholesterol level, the difference from the baseline, the average difference from the baseline and level evolution, are the considered endpoints. Specific validation criteria based on a 10% minus or plus standardized distance in means and variances were used to compare the real and the simulated data. The validity criterion was met by all models for considered endpoints. However, only two models met the validity criterion when all endpoints were considered. The model based on the assumption that within-subjects variability of cholesterol levels changes over time is the one that minimizes the validity criterion, standardized distance equal to or less than 1% minus or plus. Simulation is a useful technique for calibration, estimation, and evaluation of models, which allows us to relax the often overly restrictive assumptions regarding parameters required by analytical approaches. The validity criterion can also be used to select the preferred model for design optimization, until additional data are obtained allowing an external validation of the model.

Validation of advanced NSSS simulator model for loss-of-coolant accidents

Energy Technology Data Exchange (ETDEWEB)

Kao, S.P.; Chang, S.K.; Huang, H.C. [Nuclear Training Branch, Northeast Utilities, Waterford, CT (United States)

1995-09-01

The replacement of the NSSS (Nuclear Steam Supply System) model on the Millstone 2 full-scope simulator has significantly increased its fidelity to simulate adverse conditions in the RCS. The new simulator NSSS model is a real-time derivative of the Nuclear Plant Analyzer by ABB. The thermal-hydraulic model is a five-equation, non-homogeneous model for water, steam, and non-condensible gases. The neutronic model is a three-dimensional nodal diffusion model. In order to certify the new NSSS model for operator training, an extensive validation effort has been performed by benchmarking the model performance against RELAP5/MOD2. This paper presents the validation results for the cases of small-and large-break loss-of-coolant accidents (LOCA). Detailed comparisons in the phenomena of reflux-condensation, phase separation, and two-phase natural circulation are discussed.

Statistical Analysis Methods for Physics Models Verification and Validation

CERN Document Server

De Luca, Silvia

2017-01-01

The validation and verification process is a fundamental step for any software like Geant4 and GeantV, which aim to perform data simulation using physics models and Monte Carlo techniques. As experimental physicists, we have to face the problem to compare the results obtained using simulations with what the experiments actually observed. One way to solve the problem is to perform a consistency test. Within the Geant group, we developed a C++ compact library which will be added to the automated validation process on the Geant Validation Portal

Isotopes as validation tools for global climate models

International Nuclear Information System (INIS)

Henderson-Sellers, A.

2001-01-01

Global Climate Models (GCMs) are the predominant tool with which we predict the future climate. In order that people can have confidence in such predictions, GCMs require validation. As almost every available item of meteorological data has been exploited in the construction and tuning of GCMs to date, independent validation is very difficult. This paper explores the use of isotopes as a novel and fully independent means of evaluating GCMs. The focus is the Amazon Basin which has a long history of isotope collection and analysis and also of climate modelling: both having been reported for over thirty years. Careful consideration of the results of GCM simulations of Amazonian deforestation and climate change suggests that the recent stable isotope record is more consistent with the predicted effects of greenhouse warming, possibly combined with forest removal, than with GCM predictions of the effects of deforestation alone

Validation of a Wave-Body Interaction Model by Experimental Tests

DEFF Research Database (Denmark)

Ferri, Francesco; Kramer, Morten; Pecher, Arthur

2013-01-01

Within the wave energy field, numerical simulation has recently acquired a worldwide consent as being a useful tool, besides physical model testing. The main goal of this work is the validation of a numerical model by experimental results. The numerical model is based on a linear wave-body intera...

Verification and Validation of Heat Transfer Model of AGREE Code

Energy Technology Data Exchange (ETDEWEB)

Tak, N. I. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Seker, V.; Drzewiecki, T. J.; Downar, T. J. [Department of Nuclear Engineering and Radiological Sciences, Univ. of Michigan, Michigan (United States); Kelly, J. M. [US Nuclear Regulatory Commission, Washington (United States)

2013-05-15

The AGREE code was originally developed as a multi physics simulation code to perform design and safety analysis of Pebble Bed Reactors (PBR). Currently, additional capability for the analysis of Prismatic Modular Reactor (PMR) core is in progress. Newly implemented fluid model for a PMR core is based on a subchannel approach which has been widely used in the analyses of light water reactor (LWR) cores. A hexagonal fuel (or graphite block) is discretized into triangular prism nodes having effective conductivities. Then, a meso-scale heat transfer model is applied to the unit cell geometry of a prismatic fuel block. Both unit cell geometries of multi-hole and pin-in-hole types of prismatic fuel blocks are considered in AGREE. The main objective of this work is to verify and validate the heat transfer model newly implemented for a PMR core in the AGREE code. The measured data in the HENDEL experiment were used for the validation of the heat transfer model for a pin-in-hole fuel block. However, the HENDEL tests were limited to only steady-state conditions of pin-in-hole fuel blocks. There exist no available experimental data regarding a heat transfer in multi-hole fuel blocks. Therefore, numerical benchmarks using conceptual problems are considered to verify the heat transfer model of AGREE for multi-hole fuel blocks as well as transient conditions. The CORONA and GAMMA+ codes were used to compare the numerical results. In this work, the verification and validation study were performed for the heat transfer model of the AGREE code using the HENDEL experiment and the numerical benchmarks of selected conceptual problems. The results of the present work show that the heat transfer model of AGREE is accurate and reliable for prismatic fuel blocks. Further validation of AGREE is in progress for a whole reactor problem using the HTTR safety test data such as control rod withdrawal tests and loss-of-forced convection tests.

SWAT application in intensive irrigation systems: Model modification, calibration and validation

Science.gov (United States)

Dechmi, Farida; Burguete, Javier; Skhiri, Ahmed

2012-11-01

SummaryThe Soil and Water Assessment Tool (SWAT) is a well established, distributed, eco-hydrologic model. However, using the study case of an agricultural intensive irrigated watershed, it was shown that all the model versions are not able to appropriately reproduce the total streamflow in such system when the irrigation source is outside the watershed. The objective of this study was to modify the SWAT2005 version for correctly simulating the main hydrological processes. Crop yield, total streamflow, total suspended sediment (TSS) losses and phosphorus load calibration and validation were performed using field survey information and water quantity and quality data recorded during 2008 and 2009 years in Del Reguero irrigated watershed in Spain. The goodness of the calibration and validation results was assessed using five statistical measures, including the Nash-Sutcliffe efficiency (NSE). Results indicated that the average annual crop yield and actual evapotranspiration estimations were quite satisfactory. On a monthly basis, the values of NSE were 0.90 (calibration) and 0.80 (validation) indicating that the modified model could reproduce accurately the observed streamflow. The TSS losses were also satisfactorily estimated (NSE = 0.72 and 0.52 for the calibration and validation steps). The monthly temporal patterns and all the statistical parameters indicated that the modified SWAT-IRRIG model adequately predicted the total phosphorus (TP) loading. Therefore, the model could be used to assess the impacts of different best management practices on nonpoint phosphorus losses in irrigated systems.

St. Louis FUSRAP Lessons Learned

International Nuclear Information System (INIS)

Eberlin, J.; Williams, D.; Mueller, D.

2003-01-01

The purpose of this paper is to present lessons learned from fours years' experience conducting Remedial Investigation and Remedial Action activities at the St. Louis Downtown Site (SLDS) under the Formerly Utilized Sites Remedial Action Program (FUSRAP). Many FUSRAP sites are experiencing challenges conducting Remedial Actions within forecasted volume and budget estimates. The St. Louis FUSRAP lessons learned provide insight to options for cost effective remediation at FUSRAP sites. The lessons learned are focused on project planning (budget and schedule), investigation, design, and construction

External validation of multivariable prediction models: a systematic review of methodological conduct and reporting

Science.gov (United States)

2014-01-01

Background Before considering whether to use a multivariable (diagnostic or prognostic) prediction model, it is essential that its performance be evaluated in data that were not used to develop the model (referred to as external validation). We critically appraised the methodological conduct and reporting of external validation studies of multivariable prediction models. Methods We conducted a systematic review of articles describing some form of external validation of one or more multivariable prediction models indexed in PubMed core clinical journals published in 2010. Study data were extracted in duplicate on design, sample size, handling of missing data, reference to the original study developing the prediction models and predictive performance measures. Results 11,826 articles were identified and 78 were included for full review, which described the evaluation of 120 prediction models. in participant data that were not used to develop the model. Thirty-three articles described both the development of a prediction model and an evaluation of its performance on a separate dataset, and 45 articles described only the evaluation of an existing published prediction model on another dataset. Fifty-seven percent of the prediction models were presented and evaluated as simplified scoring systems. Sixteen percent of articles failed to report the number of outcome events in the validation datasets. Fifty-four percent of studies made no explicit mention of missing data. Sixty-seven percent did not report evaluating model calibration whilst most studies evaluated model discrimination. It was often unclear whether the reported performance measures were for the full regression model or for the simplified models. Conclusions The vast majority of studies describing some form of external validation of a multivariable prediction model were poorly reported with key details frequently not presented. The validation studies were characterised by poor design, inappropriate handling

Object-oriented simulation model of a parabolic trough solar collector: Static and dynamic validation

Science.gov (United States)

Ubieta, Eduardo; Hoyo, Itzal del; Valenzuela, Loreto; Lopez-Martín, Rafael; Peña, Víctor de la; López, Susana

2017-06-01

A simulation model of a parabolic-trough solar collector developed in Modelica® language is calibrated and validated. The calibration is performed in order to approximate the behavior of the solar collector model to a real one due to the uncertainty in some of the system parameters, i.e. measured data is used during the calibration process. Afterwards, the validation of this calibrated model is done. During the validation, the results obtained from the model are compared to the ones obtained during real operation in a collector from the Plataforma Solar de Almeria (PSA).

Experimental Testing Procedures and Dynamic Model Validation for Vanadium Redox Flow Battery Storage System

DEFF Research Database (Denmark)

Baccino, Francesco; Marinelli, Mattia; Nørgård, Per Bromand

2013-01-01

The paper aims at characterizing the electrochemical and thermal parameters of a 15 kW/320 kWh vanadium redox flow battery (VRB) installed in the SYSLAB test facility of the DTU Risø Campus and experimentally validating the proposed dynamic model realized in Matlab-Simulink. The adopted testing...... efficiency of the battery system. The test procedure has general validity and could also be used for other storage technologies. The storage model proposed and described is suitable for electrical studies and can represent a general model in terms of validity. Finally, the model simulation outputs...

Development and Validation of Information Technology Mentor Teacher Attitude Scale: A Pilot Study

Science.gov (United States)

Saltan, Fatih

2015-01-01

The aim of this study development and validation of a teacher attitude scale toward Information Technology Mentor Teachers (ITMT). ITMTs give technological support to other teachers for integration of technology in their lessons. In the literature, many instruments have been developed to measure teachers' attitudes towards the technological tools…

A Relevant Lesson: Hitler Goes to the Mall

Science.gov (United States)

Gerwin, David

2003-01-01

A "Motivation" eliciting the "Aim" of each lesson initiates each lesson in the orthodox "developmental lesson-plan" that has dominated classroom instruction in NYC public schools for at least the past half-century. An action-research study of 38 lesson-plans (over 5 each from 5 teachers) drawn from student-teaching…

Model-Based Method for Sensor Validation

Science.gov (United States)

Vatan, Farrokh

2012-01-01

Fault detection, diagnosis, and prognosis are essential tasks in the operation of autonomous spacecraft, instruments, and in situ platforms. One of NASA s key mission requirements is robust state estimation. Sensing, using a wide range of sensors and sensor fusion approaches, plays a central role in robust state estimation, and there is a need to diagnose sensor failure as well as component failure. Sensor validation can be considered to be part of the larger effort of improving reliability and safety. The standard methods for solving the sensor validation problem are based on probabilistic analysis of the system, from which the method based on Bayesian networks is most popular. Therefore, these methods can only predict the most probable faulty sensors, which are subject to the initial probabilities defined for the failures. The method developed in this work is based on a model-based approach and provides the faulty sensors (if any), which can be logically inferred from the model of the system and the sensor readings (observations). The method is also more suitable for the systems when it is hard, or even impossible, to find the probability functions of the system. The method starts by a new mathematical description of the problem and develops a very efficient and systematic algorithm for its solution. The method builds on the concepts of analytical redundant relations (ARRs).

Validating a perceptual distraction model using a personal two-zone sound system

DEFF Research Database (Denmark)

Rämö, Jussi; Christensen, Lasse; Bech, Søren

2017-01-01

This paper focuses on validating a perceptual distraction model, which aims to predict user's perceived distraction caused by audio-on-audio interference. Originally, the distraction model was trained with music targets and interferers using a simple loudspeaker setup, consisting of only two...... sound zones within the sound-zone system. Thus, validating the model using a different sound-zone system with both speech-on-music and music-on-speech stimuli sets. The results show that the model performance is equally good in both zones, i.e., with both speech- on-music and music-on-speech stimuli...

Implementation and automated validation of the minimal Z' model in FeynRules

International Nuclear Information System (INIS)

Basso, L.; Christensen, N.D.; Duhr, C.; Fuks, B.; Speckner, C.

2012-01-01

We describe the implementation of a well-known class of U(1) gauge models, the 'minimal' Z' models, in FeynRules. We also describe a new automated validation tool for FeynRules models which is controlled by a web interface and allows the user to run a complete set of 2 → 2 processes on different matrix element generators, different gauges, and compare between them all. If existing, the comparison with independent implementations is also possible. This tool has been used to validate our implementation of the 'minimal' Z' models. (authors)

Developing a model for hospital inherent safety assessment: Conceptualization and validation.

Science.gov (United States)

Yari, Saeed; Akbari, Hesam; Gholami Fesharaki, Mohammad; Khosravizadeh, Omid; Ghasemi, Mohammad; Barsam, Yalda; Akbari, Hamed

2018-01-01

Paying attention to the safety of hospitals, as the most crucial institute for providing medical and health services wherein a bundle of facilities, equipment, and human resource exist, is of significant importance. The present research aims at developing a model for assessing hospitals' safety based on principles of inherent safety design. Face validity (30 experts), content validity (20 experts), construct validity (268 examples), convergent validity, and divergent validity have been employed to validate the prepared questionnaire; and the items analysis, the Cronbach's alpha test, ICC test (to measure reliability of the test), composite reliability coefficient have been used to measure primary reliability. The relationship between variables and factors has been confirmed at 0.05 significance level by conducting confirmatory factor analysis (CFA) and structural equations modeling (SEM) technique with the use of Smart-PLS. R-square and load factors values, which were higher than 0.67 and 0.300 respectively, indicated the strong fit. Moderation (0.970), simplification (0.959), substitution (0.943), and minimization (0.5008) have had the most weights in determining the inherent safety of hospital respectively. Moderation, simplification, and substitution, among the other dimensions, have more weight on the inherent safety, while minimization has the less weight, which could be due do its definition as to minimize the risk.

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

Sewer solids separation by sedimentation--the problem of modeling, validation and transferability.

Science.gov (United States)

Kutzner, R; Brombach, H; Geiger, W F

2007-01-01

Sedimentation of sewer solids in tanks, ponds and similar devices is the most relevant process for the treatment of stormwater and combined sewer overflows in urban collecting systems. In the past a lot of research work was done to develop deterministic models for the description of this separation process. But these modern models are not commonly accepted in Germany until today. Water Authorities are sceptical with regard to model validation and transferability. Within this paper it is checked whether this scepticism is reasonable. A framework-proposal for the validation of mathematical models with zero or one dimensional spatial resolution for particle separation processes for stormwater and combined sewer overflow treatment is presented. This proposal was applied to publications of repute on sewer solids separation by sedimentation. The result was that none of the investigated models described in literature passed the validation entirely. There is an urgent need for future research in sewer solids sedimentation and remobilization!

Dynamic modeling and experimental validation for direct contact membrane distillation (DCMD) process

KAUST Repository

Eleiwi, Fadi

2016-02-01

This work proposes a mathematical dynamic model for the direct contact membrane distillation (DCMD) process. The model is based on a 2D Advection–Diffusion Equation (ADE), which describes the heat and mass transfer mechanisms that take place inside the DCMD module. The model studies the behavior of the process in the time varying and the steady state phases, contributing to understanding the process performance, especially when it is driven by intermittent energy supply, such as the solar energy. The model is experimentally validated in the steady state phase, where the permeate flux is measured for different feed inlet temperatures and the maximum absolute error recorded is 2.78 °C. Moreover, experimental validation includes the time variation phase, where the feed inlet temperature ranges from 30 °C to 75 °C with 0.1 °C increment every 2min. The validation marks relative error to be less than 5%, which leads to a strong correlation between the model predictions and the experiments.

Dynamic modeling and experimental validation for direct contact membrane distillation (DCMD) process

KAUST Repository

Eleiwi, Fadi; Ghaffour, NorEddine; Alsaadi, Ahmad Salem; Francis, Lijo; Laleg-Kirati, Taous-Meriem

2016-01-01

This work proposes a mathematical dynamic model for the direct contact membrane distillation (DCMD) process. The model is based on a 2D Advection–Diffusion Equation (ADE), which describes the heat and mass transfer mechanisms that take place inside the DCMD module. The model studies the behavior of the process in the time varying and the steady state phases, contributing to understanding the process performance, especially when it is driven by intermittent energy supply, such as the solar energy. The model is experimentally validated in the steady state phase, where the permeate flux is measured for different feed inlet temperatures and the maximum absolute error recorded is 2.78 °C. Moreover, experimental validation includes the time variation phase, where the feed inlet temperature ranges from 30 °C to 75 °C with 0.1 °C increment every 2min. The validation marks relative error to be less than 5%, which leads to a strong correlation between the model predictions and the experiments.

Validating Animal Models

Directory of Open Access Journals (Sweden)

Nina Atanasova

2015-06-01

Full Text Available In this paper, I respond to the challenge raised against contemporary experimental neurobiology according to which the field is in a state of crisis because of the multiple experimental protocols employed in different laboratories and strengthening their reliability that presumably preclude the validity of neurobiological knowledge. I provide an alternative account of experimentation in neurobiology which makes sense of its experimental practices. I argue that maintaining a multiplicity of experimental protocols and strengthening their reliability are well justified and they foster rather than preclude the validity of neurobiological knowledge. Thus, their presence indicates thriving rather than crisis of experimental neurobiology.

Context discovery using attenuated Bloom codes: model description and validation

NARCIS (Netherlands)

Liu, F.; Heijenk, Geert

A novel approach to performing context discovery in ad-hoc networks based on the use of attenuated Bloom filters is proposed in this report. In order to investigate the performance of this approach, a model has been developed. This document describes the model and its validation. The model has been

Validation of the WATEQ4 geochemical model for uranium

International Nuclear Information System (INIS)

Krupka, K.M.; Jenne, E.A.; Deutsch, W.J.

1983-09-01

As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite [UO 2 (OH) 2 . H 2 O], UO 2 (OH) 2 , and rutherfordine ((UO 2 CO 3 ) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions

Beautiful Beads: A Lesson in Making Beads with Friendly Clay. AMACO[R] Lesson.

Science.gov (United States)

Gamble, Harriet; Gamble, David

This lesson resource includes a brief summary of the history of bead making and historic fascination with beads as adornment. A focus on design elements, color theory, craftsmanship, and technical skill in bead making is encouraged. The plan includes lesson goals and objectives; background preparation; a glossary of terms; a list of supplies; and…

A practical guide for operational validation of discrete simulation models

Directory of Open Access Journals (Sweden)

Fabiano Leal

2011-04-01

Full Text Available As the number of simulation experiments increases, the necessity for validation and verification of these models demands special attention on the part of the simulation practitioners. By analyzing the current scientific literature, it is observed that the operational validation description presented in many papers does not agree on the importance designated to this process and about its applied techniques, subjective or objective. With the expectation of orienting professionals, researchers and students in simulation, this article aims to elaborate a practical guide through the compilation of statistical techniques in the operational validation of discrete simulation models. Finally, the guide's applicability was evaluated by using two study objects, which represent two manufacturing cells, one from the automobile industry and the other from a Brazilian tech company. For each application, the guide identified distinct steps, due to the different aspects that characterize the analyzed distributions

Development and Validation of a Predictive Model for Functional Outcome After Stroke Rehabilitation: The Maugeri Model.

Science.gov (United States)

Scrutinio, Domenico; Lanzillo, Bernardo; Guida, Pietro; Mastropasqua, Filippo; Monitillo, Vincenzo; Pusineri, Monica; Formica, Roberto; Russo, Giovanna; Guarnaschelli, Caterina; Ferretti, Chiara; Calabrese, Gianluigi

2017-12-01

Prediction of outcome after stroke rehabilitation may help clinicians in decision-making and planning rehabilitation care. We developed and validated a predictive tool to estimate the probability of achieving improvement in physical functioning (model 1) and a level of independence requiring no more than supervision (model 2) after stroke rehabilitation. The models were derived from 717 patients admitted for stroke rehabilitation. We used multivariable logistic regression analysis to build each model. Then, each model was prospectively validated in 875 patients. Model 1 included age, time from stroke occurrence to rehabilitation admission, admission motor and cognitive Functional Independence Measure scores, and neglect. Model 2 included age, male gender, time since stroke onset, and admission motor and cognitive Functional Independence Measure score. Both models demonstrated excellent discrimination. In the derivation cohort, the area under the curve was 0.883 (95% confidence intervals, 0.858-0.910) for model 1 and 0.913 (95% confidence intervals, 0.884-0.942) for model 2. The Hosmer-Lemeshow χ 2 was 4.12 ( P =0.249) and 1.20 ( P =0.754), respectively. In the validation cohort, the area under the curve was 0.866 (95% confidence intervals, 0.840-0.892) for model 1 and 0.850 (95% confidence intervals, 0.815-0.885) for model 2. The Hosmer-Lemeshow χ 2 was 8.86 ( P =0.115) and 34.50 ( P =0.001), respectively. Both improvement in physical functioning (hazard ratios, 0.43; 0.25-0.71; P =0.001) and a level of independence requiring no more than supervision (hazard ratios, 0.32; 0.14-0.68; P =0.004) were independently associated with improved 4-year survival. A calculator is freely available for download at https://goo.gl/fEAp81. This study provides researchers and clinicians with an easy-to-use, accurate, and validated predictive tool for potential application in rehabilitation research and stroke management. © 2017 American Heart Association, Inc.

Verification and Validation of FAARR Model and Data Envelopment Analysis Models for United States Army Recruiting

National Research Council Canada - National Science Library

Piskator, Gene

1998-01-01

...) model and to develop a Data Envelopment Analysis (DEA) modeling strategy. First, the FAARR model was verified using a simulation of a known production function and validated using sensitivity analysis and ex-post forecasts...

Towards a realistic approach to validation of reactive transport models for performance assessment

International Nuclear Information System (INIS)

Siegel, M.D.

1993-01-01

Performance assessment calculations are based on geochemical models that assume that interactions among radionuclides, rocks and groundwaters under natural conditions, can be estimated or bound by data obtained from laboratory-scale studies. The data include radionuclide distribution coefficients, measured in saturated batch systems of powdered rocks, and retardation factors measured in short-term column experiments. Traditional approaches to model validation cannot be applied in a straightforward manner to the simple reactive transport models that use these data. An approach to model validation in support of performance assessment is described in this paper. It is based on a recognition of different levels of model validity and is compatible with the requirements of current regulations for high-level waste disposal. Activities that are being carried out in support of this approach include (1) laboratory and numerical experiments to test the validity of important assumptions inherent in current performance assessment methodologies,(2) integrated transport experiments, and (3) development of a robust coupled reaction/transport code for sensitivity analyses using massively parallel computers

Results from the Savannah River Laboratory model validation workshop

International Nuclear Information System (INIS)

Pepper, D.W.

1981-01-01

To evaluate existing and newly developed air pollution models used in DOE-funded laboratories, the Savannah River Laboratory sponsored a model validation workshop. The workshop used Kr-85 measurements and meteorology data obtained at SRL during 1975 to 1977. Individual laboratories used models to calculate daily, weekly, monthly or annual test periods. Cumulative integrated air concentrations were reported at each grid point and at each of the eight sampler locations

Implementation and validation of the condensation model for containment hydrogen distribution studies

International Nuclear Information System (INIS)

Ravva, Srinivasa Rao; Iyer, Kannan N.; Gupta, S.K.; Gaikwad, Avinash J.

2014-01-01

Highlights: • A condensation model based on diffusion was implemented in FLUENT. • Validation of a condensation model for the H 2 distribution studies was performed. • Multi-component diffusion is used in the present work. • Appropriate grid and turbulence model were identified. - Abstract: This paper aims at the implementation details of a condensation model in the CFD code FLUENT and its validation so that it can be used in performing the containment hydrogen distribution studies. In such studies, computational fluid dynamics simulations are necessary for obtaining accurate predictions. While steam condensation plays an important role, commercial CFD codes such as FLUENT do not have an in-built condensation model. Therefore, a condensation model was developed and implemented in the FLUENT code through user defined functions (UDFs) for the sink terms in the mass, momentum, energy and species balance equations together with associated turbulence quantities viz., kinetic energy and dissipation rate. The implemented model was validated against the ISP-47 test of TOSQAN facility using the standard wall functions and enhanced wall treatment approaches. The best suitable grid size and the turbulence model for the low density gas (He) distribution studies are brought out in this paper

System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

Energy Technology Data Exchange (ETDEWEB)

Freeman, Janine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Whitmore, Jonathan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kaffine, Leah [National Renewable Energy Lab. (NREL), Golden, CO (United States); Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron P. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2013-12-01

The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

Validating soil phosphorus routines in the SWAT model

Science.gov (United States)

Phosphorus transfer from agricultural soils to surface waters is an important environmental issue. Commonly used models like SWAT have not always been updated to reflect improved understanding of soil P transformations and transfer to runoff. Our objective was to validate the ability of the P routin...

An integrated approach for the validation of energy and environmental system analysis models : used in the validation of the Flexigas Excel BioGas model

NARCIS (Netherlands)

Pierie, Frank; van Someren, Christian; Liu, Wen; Bekkering, Jan; Hengeveld, Evert Jan; Holstein, J.; Benders, René M.J.; Laugs, Gideon A.H.; van Gemert, Wim; Moll, Henri C.

2016-01-01

A review has been completed for a verification and validation (V&V) of the (Excel) BioGas simulator or EBS model. The EBS model calculates the environmental impact of biogas production pathways using Material and Energy Flow Analysis, time dependent dynamics, geographic information, and Life Cycle

Improvement and Validation of Weld Residual Stress Modelling Procedure

International Nuclear Information System (INIS)

Zang, Weilin; Gunnars, Jens; Dong, Pingsha; Hong, Jeong K.

2009-06-01

The objective of this work is to identify and evaluate improvements for the residual stress modelling procedure currently used in Sweden. There is a growing demand to eliminate any unnecessary conservatism involved in residual stress assumptions. The study was focused on the development and validation of an improved weld residual stress modelling procedure, by taking advantage of the recent advances in residual stress modelling and stress measurement techniques. The major changes applied in the new weld residual stress modelling procedure are: - Improved procedure for heat source calibration based on use of analytical solutions. - Use of an isotropic hardening model where mixed hardening data is not available. - Use of an annealing model for improved simulation of strain relaxation in re-heated material. The new modelling procedure is demonstrated to capture the main characteristics of the through thickness stress distributions by validation to experimental measurements. Three austenitic stainless steel butt-welds cases are analysed, covering a large range of pipe geometries. From the cases it is evident that there can be large differences between the residual stresses predicted using the new procedure, and the earlier procedure or handbook recommendations. Previously recommended profiles could give misleading fracture assessment results. The stress profiles according to the new procedure agree well with the measured data. If data is available then a mixed hardening model should be used

Improvement and Validation of Weld Residual Stress Modelling Procedure

Energy Technology Data Exchange (ETDEWEB)

Zang, Weilin; Gunnars, Jens (Inspecta Technology AB, Stockholm (Sweden)); Dong, Pingsha; Hong, Jeong K. (Center for Welded Structures Research, Battelle, Columbus, OH (United States))

2009-06-15

The objective of this work is to identify and evaluate improvements for the residual stress modelling procedure currently used in Sweden. There is a growing demand to eliminate any unnecessary conservatism involved in residual stress assumptions. The study was focused on the development and validation of an improved weld residual stress modelling procedure, by taking advantage of the recent advances in residual stress modelling and stress measurement techniques. The major changes applied in the new weld residual stress modelling procedure are: - Improved procedure for heat source calibration based on use of analytical solutions. - Use of an isotropic hardening model where mixed hardening data is not available. - Use of an annealing model for improved simulation of strain relaxation in re-heated material. The new modelling procedure is demonstrated to capture the main characteristics of the through thickness stress distributions by validation to experimental measurements. Three austenitic stainless steel butt-welds cases are analysed, covering a large range of pipe geometries. From the cases it is evident that there can be large differences between the residual stresses predicted using the new procedure, and the earlier procedure or handbook recommendations. Previously recommended profiles could give misleading fracture assessment results. The stress profiles according to the new procedure agree well with the measured data. If data is available then a mixed hardening model should be used

Calibration and validation of earthquake catastrophe models. Case study: Impact Forecasting Earthquake Model for Algeria

Science.gov (United States)

Trendafiloski, G.; Gaspa Rebull, O.; Ewing, C.; Podlaha, A.; Magee, B.

2012-04-01

Calibration and validation are crucial steps in the production of the catastrophe models for the insurance industry in order to assure the model's reliability and to quantify its uncertainty. Calibration is needed in all components of model development including hazard and vulnerability. Validation is required to ensure that the losses calculated by the model match those observed in past events and which could happen in future. Impact Forecasting, the catastrophe modelling development centre of excellence within Aon Benfield, has recently launched its earthquake model for Algeria as a part of the earthquake model for the Maghreb region. The earthquake model went through a detailed calibration process including: (1) the seismic intensity attenuation model by use of macroseismic observations and maps from past earthquakes in Algeria; (2) calculation of the country-specific vulnerability modifiers by use of past damage observations in the country. The use of Benouar, 1994 ground motion prediction relationship was proven as the most appropriate for our model. Calculation of the regional vulnerability modifiers for the country led to 10% to 40% larger vulnerability indexes for different building types compared to average European indexes. The country specific damage models also included aggregate damage models for residential, commercial and industrial properties considering the description of the buildings stock given by World Housing Encyclopaedia and the local rebuilding cost factors equal to 10% for damage grade 1, 20% for damage grade 2, 35% for damage grade 3, 75% for damage grade 4 and 100% for damage grade 5. The damage grades comply with the European Macroseismic Scale (EMS-1998). The model was validated by use of "as-if" historical scenario simulations of three past earthquake events in Algeria M6.8 2003 Boumerdes, M7.3 1980 El-Asnam and M7.3 1856 Djidjelli earthquake. The calculated return periods of the losses for client market portfolio align with the

Three phase heat and mass transfer model for unsaturated soil freezing process: Part 2 - model validation

Science.gov (United States)

Zhang, Yaning; Xu, Fei; Li, Bingxi; Kim, Yong-Song; Zhao, Wenke; Xie, Gongnan; Fu, Zhongbin

2018-04-01

This study aims to validate the three-phase heat and mass transfer model developed in the first part (Three phase heat and mass transfer model for unsaturated soil freezing process: Part 1 - model development). Experimental results from studies and experiments were used for the validation. The results showed that the correlation coefficients for the simulated and experimental water contents at different soil depths were between 0.83 and 0.92. The correlation coefficients for the simulated and experimental liquid water contents at different soil temperatures were between 0.95 and 0.99. With these high accuracies, the developed model can be well used to predict the water contents at different soil depths and temperatures.

Validation of NEPTUNE-CFD two-phase flow models using experimental data

International Nuclear Information System (INIS)

Perez-Manes, Jorge; Sanchez Espinoza, Victor Hugo; Bottcher, Michael; Stieglitz, Robert; Sergio Chiva Vicent

2014-01-01

This paper deals with the validation of the two-phase flow models of the CFD code NEPTUNE-CFD using experimental data provided by the OECD BWR BFBT and PSBT Benchmark. Since the two-phase models of CFD codes are extensively being improved, the validation is a key step for the acceptability of such codes. The validation work is performed in the frame of the European NURISP Project and it was focused on the steady state and transient void fraction tests. The influence of different NEPTUNE-CFD model parameters on the void fraction prediction is investigated and discussed in detail. Due to the coupling of heat conduction solver SYRTHES with NEPTUNE-CFD, the description of the coupled fluid dynamics and heat transfer between the fuel rod and the fluid is improved significantly. The averaged void fraction predicted by NEPTUNE-CFD for selected PSBT and BFBT tests is in good agreement with the experimental data. Finally, areas for future improvements of the NEPTUNE-CFD code were identified, too. (authors)

Flight Testing an Iced Business Jet for Flight Simulation Model Validation

Science.gov (United States)

Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam; Cooper, Jon

2007-01-01

A flight test of a business jet aircraft with various ice accretions was performed to obtain data to validate flight simulation models developed through wind tunnel tests. Three types of ice accretions were tested: pre-activation roughness, runback shapes that form downstream of the thermal wing ice protection system, and a wing ice protection system failure shape. The high fidelity flight simulation models of this business jet aircraft were validated using a software tool called "Overdrive." Through comparisons of flight-extracted aerodynamic forces and moments to simulation-predicted forces and moments, the simulation models were successfully validated. Only minor adjustments in the simulation database were required to obtain adequate match, signifying the process used to develop the simulation models was successful. The simulation models were implemented in the NASA Ice Contamination Effects Flight Training Device (ICEFTD) to enable company pilots to evaluate flight characteristics of the simulation models. By and large, the pilots confirmed good similarities in the flight characteristics when compared to the real airplane. However, pilots noted pitch up tendencies at stall with the flaps extended that were not representative of the airplane and identified some differences in pilot forces. The elevator hinge moment model and implementation of the control forces on the ICEFTD were identified as a driver in the pitch ups and control force issues, and will be an area for future work.

Pre-engineering Spaceflight Validation of Environmental Models and the 2005 HZETRN Simulation Code

Science.gov (United States)

Nealy, John E.; Cucinotta, Francis A.; Wilson, John W.; Badavi, Francis F.; Dachev, Ts. P.; Tomov, B. T.; Walker, Steven A.; DeAngelis, Giovanni; Blattnig, Steve R.; Atwell, William

2006-01-01

The HZETRN code has been identified by NASA for engineering design in the next phase of space exploration highlighting a return to the Moon in preparation for a Mars mission. In response, a new series of algorithms beginning with 2005 HZETRN, will be issued by correcting some prior limitations and improving control of propagated errors along with established code verification processes. Code validation processes will use new/improved low Earth orbit (LEO) environmental models with a recently improved International Space Station (ISS) shield model to validate computational models and procedures using measured data aboard ISS. These validated models will provide a basis for flight-testing the designs of future space vehicles and systems of the Constellation program in the LEO environment.

Validating a perceptual distraction model in a personal two-zone sound system

DEFF Research Database (Denmark)

Rämö, Jussi; Christensen, Lasse; Bech, Søren

2017-01-01

This paper focuses on validating a perceptual distraction model, which aims to predict user’s perceived distraction caused by audio-on-audio interference, e.g., two competing audio sources within the same listening space. Originally, the distraction model was trained with music-on-music stimuli...... that the model performance is equally good in both zones, i.e., with both speech-on-music and music-on-speech stimuli, and comparable to the previous validation round (RMSE approximately 10%). The results further confirm that the distraction model can be used as a valuable tool in evaluating and optimizing...

A Component-Based Modeling and Validation Method for PLC Systems

Directory of Open Access Journals (Sweden)

Rui Wang

2014-05-01

Full Text Available Programmable logic controllers (PLCs are complex embedded systems that are widely used in industry. This paper presents a component-based modeling and validation method for PLC systems using the behavior-interaction-priority (BIP framework. We designed a general system architecture and a component library for a type of device control system. The control software and hardware of the environment were all modeled as BIP components. System requirements were formalized as monitors. Simulation was carried out to validate the system model. A realistic example from industry of the gates control system was employed to illustrate our strategies. We found a couple of design errors during the simulation, which helped us to improve the dependability of the original systems. The results of experiment demonstrated the effectiveness of our approach.

The 'Ottoman-German Jihad': Lessons for the Contemporary 'Area Studies' Controversy

DEFF Research Database (Denmark)

Jung, Dietrich

2014-01-01

The 'Arab Spring' added new fuel to the ongoing controversy over the validity of regional or area studies. None of the Middle East 'area experts' predicted the revolutionary events that led to the fall of a number of authoritarian rulers in the Arab world. As a result, scholars, the media and pol....... The article would argue that this historical dispute already reflected some of the core issues of the contemporary controversy of 'area studies' and contained some lessons for us to learn regarding the analysis of Middle Eastern economy, society and politics....

Analysing the Integration of Engineering in Science Lessons with the Engineering-Infused Lesson Rubric

Science.gov (United States)

Peterman, Karen; Daugherty, Jenny L.; Custer, Rodney L.; Ross, Julia M.

2017-01-01

Science teachers are being called on to incorporate engineering practices into their classrooms. This study explores whether the Engineering-Infused Lesson Rubric, a new rubric designed to target best practices in engineering education, could be used to evaluate the extent to which engineering is infused into online science lessons. Eighty lessons…

Modeling of surge in free-spool centrifugal compressors : experimental validation

NARCIS (Netherlands)

Gravdahl, J.T.; Willems, F.P.T.; Jager, de A.G.; Egeland, O.

2004-01-01

The derivation of a compressor characteristic, and the experimental validation of a dynamic model for a variable speed centrifugal compressor using this characteristic, are presented. The dynamic compressor model of Fink et al. is used, and a variable speed compressor characteristic is derived by

Sample size calculation to externally validate scoring systems based on logistic regression models.

Directory of Open Access Journals (Sweden)

Antonio Palazón-Bru

Full Text Available A sample size containing at least 100 events and 100 non-events has been suggested to validate a predictive model, regardless of the model being validated and that certain factors can influence calibration of the predictive model (discrimination, parameterization and incidence. Scoring systems based on binary logistic regression models are a specific type of predictive model.The aim of this study was to develop an algorithm to determine the sample size for validating a scoring system based on a binary logistic regression model and to apply it to a case study.The algorithm was based on bootstrap samples in which the area under the ROC curve, the observed event probabilities through smooth curves, and a measure to determine the lack of calibration (estimated calibration index were calculated. To illustrate its use for interested researchers, the algorithm was applied to a scoring system, based on a binary logistic regression model, to determine mortality in intensive care units.In the case study provided, the algorithm obtained a sample size with 69 events, which is lower than the value suggested in the literature.An algorithm is provided for finding the appropriate sample size to validate scoring systems based on binary logistic regression models. This could be applied to determine the sample size in other similar cases.

The validity of the 4-Skills Scan: A double validation study.

Science.gov (United States)

van Kernebeek, W G; de Kroon, M L A; Savelsbergh, G J P; Toussaint, H M

2018-06-01

Adequate gross motor skills are an essential aspect of a child's healthy development. Where physical education (PE) is part of the primary school curriculum, a strong curriculum-based emphasis on evaluation and support of motor skill development in PE is apparent. Monitoring motor development is then a task for the PE teacher. In order to fulfil this task, teachers need adequate tools. The 4-Skills Scan is a quick and easily manageable gross motor skill instrument; however, its validity has never been assessed. Therefore, the purpose of this study is to assess the construct and concurrent validity of both 4-Skills Scans (version 2007 and version 2015). A total of 212 primary school children (6 - 12 years old), was requested to participate in both versions of the 4-Skills Scan. For assessing construct validity, children covered an obstacle course with video recordings for observation by an expert panel. For concurrent validity, a comparison was made with the MABC-2, by calculating Pearson correlations. Multivariable linear regression analyses were performed to determine the contribution of each subscale to the construct of gross motor skills, according to the MABC-2 and the expert panel. Correlations between the 4-Skills Scans and expert valuations were moderate, with coefficients of .47 (version 2007) and .46 (version 2015). Correlations between the 4-Skills Scans and the MABC-2 (gross) were moderate (.56) for version 2007 and high (.64) for version 2015. It is concluded that both versions of the 4-Skills Scans are satisfactory valid instruments for assessing gross motor skills during PE lessons. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The attitudes of classroom teacher candidates towards physical education lesson

Directory of Open Access Journals (Sweden)

Gönül Tekkurşun Demir

2017-12-01

Full Text Available Aim: It is aimed to determine the attitudes of the 2nd, 3rd, and 4th grade classroom teacher candidates towards the physical education lesson according to various variables. Material and Methods: For the current study, the screening method, one of the quantitative research models, was used. The research consists of 2nd, 3rd, and 4th grade, totally164 university students, 106 (%64,6 females, 58 (%35,4 males, attending Uşak University, Classroom Teaching Program in 2016-2017 academic year. The first-grade students were not included in this research, because the physical education and play teaching lessons are given to classroom student candidates in the second-grade at Uşak University, Classroom Teaching Program. “Personal information form" and “Physical Education Lesson Attitude Scale for Classroom Teacher Candidates" were used as data collection tools. Before analysis, the data were evaluated using the values of Skewness and Skewness (normal distribution of the data and Levene (equality of variance tests. In the analysis of the data; frequency, arithmetic mean, standard deviation; t-test, ANOVA and Pearson Correlation test were used. Results: When examined the total score of the teacher candidates obtained from Physical Education Lesson Attitude Scale for Classroom Teacher Candidates and age variable by the Pearson Moment Correlation analysis, it was found that there was a statistically significant negative relationship between the received scores at low level. It was determined that the attitudes of the classroom teacher candidates towards the physical education lessons did not show any significant difference according to the gender variable, but there was a significant difference when examined their class levels. While no significant difference was found in the attitudes of the classroom teacher candidates, who played and did not play sports in their past life, towards physical education lessons, no significant difference was found

Earth as an extrasolar planet: Earth model validation using EPOXI earth observations.

Science.gov (United States)

Robinson, Tyler D; Meadows, Victoria S; Crisp, David; Deming, Drake; A'hearn, Michael F; Charbonneau, David; Livengood, Timothy A; Seager, Sara; Barry, Richard K; Hearty, Thomas; Hewagama, Tilak; Lisse, Carey M; McFadden, Lucy A; Wellnitz, Dennis D

2011-06-01

The EPOXI Discovery Mission of Opportunity reused the Deep Impact flyby spacecraft to obtain spatially and temporally resolved visible photometric and moderate resolution near-infrared (NIR) spectroscopic observations of Earth. These remote observations provide a rigorous validation of whole-disk Earth model simulations used to better understand remotely detectable extrasolar planet characteristics. We have used these data to upgrade, correct, and validate the NASA Astrobiology Institute's Virtual Planetary Laboratory three-dimensional line-by-line, multiple-scattering spectral Earth model. This comprehensive model now includes specular reflectance from the ocean and explicitly includes atmospheric effects such as Rayleigh scattering, gas absorption, and temperature structure. We have used this model to generate spatially and temporally resolved synthetic spectra and images of Earth for the dates of EPOXI observation. Model parameters were varied to yield an optimum fit to the data. We found that a minimum spatial resolution of ∼100 pixels on the visible disk, and four categories of water clouds, which were defined by using observed cloud positions and optical thicknesses, were needed to yield acceptable fits. The validated model provides a simultaneous fit to Earth's lightcurve, absolute brightness, and spectral data, with a root-mean-square (RMS) error of typically less than 3% for the multiwavelength lightcurves and residuals of ∼10% for the absolute brightness throughout the visible and NIR spectral range. We have extended our validation into the mid-infrared by comparing the model to high spectral resolution observations of Earth from the Atmospheric Infrared Sounder, obtaining a fit with residuals of ∼7% and brightness temperature errors of less than 1 K in the atmospheric window. For the purpose of understanding the observable characteristics of the distant Earth at arbitrary viewing geometry and observing cadence, our validated forward model can be

Validation of a Hot Water Distribution Model Using Laboratory and Field Data

Energy Technology Data Exchange (ETDEWEB)

Backman, C.; Hoeschele, M.

2013-07-01

Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the ARBI team validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. In addition to completing validation activities, this project looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. Based on these datasets, we conclude that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws. This has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

Experimental validation of a thermodynamic boiler model under steady state and dynamic conditions

International Nuclear Information System (INIS)

Carlon, Elisa; Verma, Vijay Kumar; Schwarz, Markus; Golicza, Laszlo; Prada, Alessandro; Baratieri, Marco; Haslinger, Walter; Schmidl, Christoph

2015-01-01

Highlights: • Laboratory tests on two commercially available pellet boilers. • Steady state and a dynamic load cycle tests. • Pellet boiler model calibration based on data registered in stationary operation. • Boiler model validation with reference to both stationary and dynamic operation. • Validated model suitable for coupled simulation of building and heating system. - Abstract: Nowadays dynamic building simulation is an essential tool for the design of heating systems for residential buildings. The simulation of buildings heated by biomass systems, first of all needs detailed boiler models, capable of simulating the boiler both as a stand-alone appliance and as a system component. This paper presents the calibration and validation of a boiler model by means of laboratory tests. The chosen model, i.e. TRNSYS “Type 869”, has been validated for two commercially available pellet boilers of 6 and 12 kW nominal capacities. Two test methods have been applied: the first is a steady state test at nominal load and the second is a load cycle test including stationary operation at different loads as well as transient operation. The load cycle test is representative of the boiler operation in the field and characterises the boiler’s stationary and dynamic behaviour. The model had been calibrated based on laboratory data registered during stationary operation at different loads and afterwards it was validated by simulating both the stationary and the dynamic tests. Selected parameters for the validation were the heat transfer rates to water and the water temperature profiles inside the boiler and at the boiler outlet. Modelling results showed better agreement with experimental data during stationary operation rather than during dynamic operation. Heat transfer rates to water were predicted with a maximum deviation of 10% during the stationary operation, and a maximum deviation of 30% during the dynamic load cycle. However, for both operational regimes the

Validation of Slosh Modeling Approach Using STAR-CCM+

Science.gov (United States)

Benson, David J.; Ng, Wanyi

2018-01-01

Without an adequate understanding of propellant slosh, the spacecraft attitude control system may be inadequate to control the spacecraft or there may be an unexpected loss of science observation time due to higher slosh settling times. Computational fluid dynamics (CFD) is used to model propellant slosh. STAR-CCM+ is a commercially available CFD code. This paper seeks to validate the CFD modeling approach via a comparison between STAR-CCM+ liquid slosh modeling results and experimental, empirically, and analytically derived results. The geometries examined are a bare right cylinder tank and a right cylinder with a single ring baffle.

Validation of coastal oceanographic models at Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

International Nuclear Information System (INIS)

Engqvist, Anders; Andrejev, Oleg

2008-12-01

The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterization at two different locations, the Forsmark and the Laxemar-Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The characterization work is divided into an initial site investigation phase and a complete site investigation phase. In this context, the water exchange of the coastal zone is one link of the chain of possible nuclide transport mechanisms that must be assessed in the site description of potential repository areas. For the purpose of validating the pair of nested 3D-models and the coupled discrete basin (CDB-) model employed to simulate the water exchange in the near-shore coastal zone in the Laxemar-Simpevarp area, an encompassing measurement program entailing data from six stations (of which two are close) has been performed. The design of this program was to first assess to what degree the forcing of the fine resolution (FR-) model of the Laxemar- Simpevarp study area at its interfacial boundary to the coarse resolution (CR-) model of the entire Baltic was reproduced. In addition to this, it is of particular interest how the time-varying density-determining properties, salinity and temperature, at the borders are propagated into the FR-domain and further influence the water exchange with the interior, more secluded, basins. An important part of the validation process has been to carefully evaluate which measurement data that can be considered reliable. The result was that some periods of foremost near-surface salinity data had to be discarded due to growth of algae on the conductivity sensors. Interference with ship traffic and lack of absolute calibration of the salinity meters necessitated dismissal of measurement data too. In this study so-called Mesan data have been consistently used for the meteorological forcing of the 3D-models. Relative the assessed data that can be accepted as adequate, the outcome of the

Validation of coastal oceanographic models at Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

Energy Technology Data Exchange (ETDEWEB)

Engqvist, Anders (A och I Engqvist Konsult HB, Vaxholm (SE)); Andrejev, Oleg (Finnish Inst. of Marine Research, Helsinki (FI))

2008-12-15

The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterization at two different locations, the Forsmark and the Laxemar-Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The characterization work is divided into an initial site investigation phase and a complete site investigation phase. In this context, the water exchange of the coastal zone is one link of the chain of possible nuclide transport mechanisms that must be assessed in the site description of potential repository areas. For the purpose of validating the pair of nested 3D-models and the coupled discrete basin (CDB-) model employed to simulate the water exchange in the near-shore coastal zone in the Laxemar-Simpevarp area, an encompassing measurement program entailing data from six stations (of which two are close) has been performed. The design of this program was to first assess to what degree the forcing of the fine resolution (FR-) model of the Laxemar- Simpevarp study area at its interfacial boundary to the coarse resolution (CR-) model of the entire Baltic was reproduced. In addition to this, it is of particular interest how the time-varying density-determining properties, salinity and temperature, at the borders are propagated into the FR-domain and further influence the water exchange with the interior, more secluded, basins. An important part of the validation process has been to carefully evaluate which measurement data that can be considered reliable. The result was that some periods of foremost near-surface salinity data had to be discarded due to growth of algae on the conductivity sensors. Interference with ship traffic and lack of absolute calibration of the salinity meters necessitated dismissal of measurement data too. In this study so-called Mesan data have been consistently used for the meteorological forcing of the 3D-models. Relative the assessed data that can be accepted as adequate, the outcome of the

Atmospheric corrosion: statistical validation of models

International Nuclear Information System (INIS)

Diaz, V.; Martinez-Luaces, V.; Guineo-Cobs, G.

2003-01-01

In this paper we discuss two different methods for validation of regression models, applied to corrosion data. One of them is based on the correlation coefficient and the other one is the statistical test of lack of fit. Both methods are used here to analyse fitting of bi logarithmic model in order to predict corrosion for very low carbon steel substrates in rural and urban-industrial atmospheres in Uruguay. Results for parameters A and n of the bi logarithmic model are reported here. For this purpose, all repeated values were used instead of using average values as usual. Modelling is carried out using experimental data corresponding to steel substrates under the same initial meteorological conditions ( in fact, they are put in the rack at the same time). Results of correlation coefficient are compared with the lack of it tested at two different signification levels (α=0.01 and α=0.05). Unexpected differences between them are explained and finally, it is possible to conclude, at least in the studied atmospheres, that the bi logarithmic model does not fit properly the experimental data. (Author) 18 refs

Lagrangian Stochastic Dispersion Model IMS Model Suite and its Validation against Experimental Data

International Nuclear Information System (INIS)

Bartok, J.

2010-01-01

The dissertation presents IMS Lagrangian Dispersion Model, which is a 'new generation' Slovak dispersion model of long-range transport, developed by MicroStep-MIS. It solves trajectory equation for a vast number of Lagrangian 'particles' and stochastic equation that simulates the effects of turbulence. Model contains simulation of radioactive decay (full decay chains of more than 300 nuclides), and dry and wet deposition. Model was integrated into IMS Model Suite, a system in which several models and modules can run and cooperate, e.g. LAM model WRF preparing fine resolution meteorological data for dispersion. The main theme of the work is validation of dispersion model against large scale international campaigns CAPTEX and ETEX, which are two of the largest tracer experiments. Validation addressed treatment of missing data, data interpolation into comparable temporal and spatial representation. The best model results were observed for ETEX I, standard results for CAPTEXes and worst results for ETEX II, known in modelling community for its meteorological conditions that can be hardly resolved by models. The IMS Lagrangian Dispersion Model was identified as capable long range dispersion model for slowly- or nonreacting chemicals and radioactive matter. Influence of input data on simulation quality is discussed within the work. Additional modules were prepared according to praxis requirement: a) Recalculation of concentrations of radioactive pollutant into effective doses form inhalation, immersion in the plume and deposition. b) Dispersion of mineral dust was added and tested in desert locality, where wind and soil moisture were firstly analysed and forecast by WRF. The result was qualitatively verified in case study against satellite observations. (author)

Reactor core modeling practice: Operational requirements, model characteristics, and model validation

International Nuclear Information System (INIS)

Zerbino, H.

1997-01-01

The physical models implemented in power plant simulators have greatly increased in performance and complexity in recent years. This process has been enabled by the ever increasing computing power available at affordable prices. This paper describes this process from several angles: First the operational requirements which are more critical from the point of view of model performance, both for normal and off-normal operating conditions; A second section discusses core model characteristics in the light of the solutions implemented by Thomson Training and Simulation (TT and S) in several full-scope simulators recently built and delivered for Dutch, German, and French nuclear power plants; finally we consider the model validation procedures, which are of course an integral part of model development, and which are becoming more and more severe as performance expectations increase. As a conclusion, it may be asserted that in the core modeling field, as in other areas, the general improvement in the quality of simulation codes has resulted in a fairly rapid convergence towards mainstream engineering-grade calculations. This is remarkable performance in view of the stringent real-time requirements which the simulation codes must satisfy as well as the extremely wide range of operating conditions that they are called upon to cover with good accuracy. (author)

A New Statistical Method to Determine the Degree of Validity of Health Economic Model Outcomes against Empirical Data.

Science.gov (United States)

Corro Ramos, Isaac; van Voorn, George A K; Vemer, Pepijn; Feenstra, Talitha L; Al, Maiwenn J

2017-09-01

The validation of health economic (HE) model outcomes against empirical data is of key importance. Although statistical testing seems applicable, guidelines for the validation of HE models lack guidance on statistical validation, and actual validation efforts often present subjective judgment of graphs and point estimates. To discuss the applicability of existing validation techniques and to present a new method for quantifying the degrees of validity statistically, which is useful for decision makers. A new Bayesian method is proposed to determine how well HE model outcomes compare with empirical data. Validity is based on a pre-established accuracy interval in which the model outcomes should fall. The method uses the outcomes of a probabilistic sensitivity analysis and results in a posterior distribution around the probability that HE model outcomes can be regarded as valid. We use a published diabetes model (Modelling Integrated Care for Diabetes based on Observational data) to validate the outcome "number of patients who are on dialysis or with end-stage renal disease." Results indicate that a high probability of a valid outcome is associated with relatively wide accuracy intervals. In particular, 25% deviation from the observed outcome implied approximately 60% expected validity. Current practice in HE model validation can be improved by using an alternative method based on assessing whether the model outcomes fit to empirical data at a predefined level of accuracy. This method has the advantage of assessing both model bias and parameter uncertainty and resulting in a quantitative measure of the degree of validity that penalizes models predicting the mean of an outcome correctly but with overly wide credible intervals. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Selection, calibration, and validation of models of tumor growth.

Science.gov (United States)

Lima, E A B F; Oden, J T; Hormuth, D A; Yankeelov, T E; Almeida, R C

2016-11-01

This paper presents general approaches for addressing some of the most important issues in predictive computational oncology concerned with developing classes of predictive models of tumor growth. First, the process of developing mathematical models of vascular tumors evolving in the complex, heterogeneous, macroenvironment of living tissue; second, the selection of the most plausible models among these classes, given relevant observational data; third, the statistical calibration and validation of models in these classes, and finally, the prediction of key Quantities of Interest (QOIs) relevant to patient survival and the effect of various therapies. The most challenging aspects of this endeavor is that all of these issues often involve confounding uncertainties: in observational data, in model parameters, in model selection, and in the features targeted in the prediction. Our approach can be referred to as "model agnostic" in that no single model is advocated; rather, a general approach that explores powerful mixture-theory representations of tissue behavior while accounting for a range of relevant biological factors is presented, which leads to many potentially predictive models. Then representative classes are identified which provide a starting point for the implementation of OPAL, the Occam Plausibility Algorithm (OPAL) which enables the modeler to select the most plausible models (for given data) and to determine if the model is a valid tool for predicting tumor growth and morphology ( in vivo ). All of these approaches account for uncertainties in the model, the observational data, the model parameters, and the target QOI. We demonstrate these processes by comparing a list of models for tumor growth, including reaction-diffusion models, phase-fields models, and models with and without mechanical deformation effects, for glioma growth measured in murine experiments. Examples are provided that exhibit quite acceptable predictions of tumor growth in laboratory

Validation of a FAST Model of the SWAY Prototype Floating Wind Turbine

Energy Technology Data Exchange (ETDEWEB)

Koh, J. H. [Nanyang Technological Univ. (Singapore); Ng, E. Y. K. [Nanyang Technological Univ. (Singapore); Robertson, Amy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jonkman, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States); Driscoll, Frederick [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-06-01

As part of a collaboration of the National Renewable Energy Laboratory (NREL) and SWAY AS, NREL installed scientific wind, wave, and motion measurement equipment on the spar-type 1/6.5th-scale prototype SWAY floating offshore wind system. The equipment enhanced SWAY's data collection and allowed SWAY to verify the concept and NREL to validate a FAST model of the SWAY design in an open-water condition. Nanyang Technological University (NTU), in collaboration with NREL, assisted with the validation. This final report gives an overview of the SWAY prototype and NREL and NTU's efforts to validate a model of the system. The report provides a summary of the different software tools used in the study, the modeling strategies, and the development of a FAST model of the SWAY prototype wind turbine, including justification of the modeling assumptions. Because of uncertainty in system parameters and modeling assumptions due to the complexity of the design, several system properties were tuned to better represent the system and improve the accuracy of the simulations. Calibration was performed using data from a static equilibrium test and free-decay tests.

Refining and validating a conceptual model of Clinical Nurse Leader integrated care delivery.

Science.gov (United States)

Bender, Miriam; Williams, Marjory; Su, Wei; Hites, Lisle

2017-02-01

To empirically validate a conceptual model of Clinical Nurse Leader integrated care delivery. There is limited evidence of frontline care delivery models that consistently achieve quality patient outcomes. Clinical Nurse Leader integrated care delivery is a promising nursing model with a growing record of success. However, theoretical clarity is necessary to generate causal evidence of effectiveness. Sequential mixed methods. A preliminary Clinical Nurse Leader practice model was refined and survey items developed to correspond with model domains, using focus groups and a Delphi process with a multi-professional expert panel. The survey was administered in 2015 to clinicians and administrators involved in Clinical Nurse Leader initiatives. Confirmatory factor analysis and structural equation modelling were used to validate the measurement and model structure. Final sample n = 518. The model incorporates 13 components organized into five conceptual domains: 'Readiness for Clinical Nurse Leader integrated care delivery'; 'Structuring Clinical Nurse Leader integrated care delivery'; 'Clinical Nurse Leader Practice: Continuous Clinical Leadership'; 'Outcomes of Clinical Nurse Leader integrated care delivery'; and 'Value'. Sample data had good fit with specified model and two-level measurement structure. All hypothesized pathways were significant, with strong coefficients suggesting good fit between theorized and observed path relationships. The validated model articulates an explanatory pathway of Clinical Nurse Leader integrated care delivery, including Clinical Nurse Leader practices that result in improved care dynamics and patient outcomes. The validated model provides a basis for testing in practice to generate evidence that can be deployed across the healthcare spectrum. © 2016 John Wiley & Sons Ltd.

Predictive Simulation of Material Failure Using Peridynamics -- Advanced Constitutive Modeling, Verification and Validation

Science.gov (United States)

2016-03-31

AFRL-AFOSR-VA-TR-2016-0309 Predictive simulation of material failure using peridynamics- advanced constitutive modeling, verification , and validation... Self -explanatory. 8. PERFORMING ORGANIZATION REPORT NUMBER. Enter all unique alphanumeric report numbers assigned by the performing organization, e.g...for public release. Predictive simulation of material failure using peridynamics-advanced constitutive modeling, verification , and validation John T

Physical validation issue of the NEPTUNE two-phase modelling: validation plan to be adopted, experimental programs to be set up and associated instrumentation techniques developed

International Nuclear Information System (INIS)

Pierre Peturaud; Eric Hervieu

2005-01-01

Full text of publication follows: A long-term joint development program for the next generation of nuclear reactors simulation tools has been launched in 2001 by EDF (Electricite de France) and CEA (Commissariat a l'Energie Atomique). The NEPTUNE Project constitutes the Thermal-Hydraulics part of this comprehensive program. Along with the underway development of this new two-phase flow software platform, the physical validation of the involved modelling is a crucial issue, whatever the modelling scale is, and the present paper deals with this issue. After a brief recall about the NEPTUNE platform, the general validation strategy to be adopted is first of all clarified by means of three major features: (i) physical validation in close connection with the concerned industrial applications, (ii) involving (as far as possible) a two-step process successively focusing on dominant separate models and assessing the whole modelling capability, (iii) thanks to the use of relevant data with respect to the validation aims. Based on this general validation process, a four-step generic work approach has been defined; it includes: (i) a thorough analysis of the concerned industrial applications to identify the key physical phenomena involved and associated dominant basic models, (ii) an assessment of these models against the available validation pieces of information, to specify the additional validation needs and define dedicated validation plans, (iii) an inventory and assessment of existing validation data (with respect to the requirements specified in the previous task) to identify the actual needs for new validation data, (iv) the specification of the new experimental programs to be set up to provide the needed new data. This work approach has been applied to the NEPTUNE software, focusing on 8 high priority industrial applications, and it has resulted in the definition of (i) the validation plan and experimental programs to be set up for the open medium 3D modelling

Development, Validation, and Implementation of a Clinic Nurse Staffing Guideline.

Science.gov (United States)

Deeken, Debra Jean; Wakefield, Douglas; Kite, Cora; Linebaugh, Jeanette; Mitchell, Blair; Parkinson, Deidre; Misra, Madhukar

2017-10-01

Ensuring that the level of nurse staffing used to care for patients is appropriate to the setting and service intensity is essential for high-quality and cost-effective care. This article describes the development, validation, and implementation of the clinic technical skills permission list developed specifically to guide nurse staffing decisions in physician clinics of an academic medical center. Results and lessons learned in using this staffing guideline are presented.

Transformation of topic-specific professional knowledge into personal pedagogical content knowledge through lesson planning

Science.gov (United States)

Stender, Anita; Brückmann, Maja; Neumann, Knut

2017-08-01

This study investigates the relationship between two different types of pedagogical content knowledge (PCK): the topic-specific professional knowledge (TSPK) and practical routines, so-called teaching scripts. Based on the Transformation Model of Lesson Planning, we assume that teaching scripts originate from a transformation of TSPK during lesson planning: When planning lessons, teachers use their TSPK to create lesson plans. The implementation of these lesson plans and teachers' reflection upon them lead to their improvement. Gradually, successful lesson plans are mentally stored as teaching scripts and can easily be retrieved during instruction. This process is affected by teacher's beliefs, motivation and self-regulation. In order to examine the influence of TSPK on teaching scripts as well as the moderating effects of beliefs, motivation and self-regulation, we conducted a cross-sectional study with n = 49 in-service teachers in physics. The TSPK, beliefs, motivation, self-regulation and the quality of teaching scripts of in-service teachers were assessed by using an online questionnaire adapted to teaching the force concept and Newton's law for 9th grade instruction. Based on the measurement of the quality of teaching scripts, the results provide evidence that TSPK influences the quality of teaching scripts. Motivation and self-regulation moderate this influence.

Validation of the hdm models forcrack initiation and development, rutting and roughness of the pavement

Directory of Open Access Journals (Sweden)

Ognjenović Slobodan

2017-01-01

Full Text Available Worldwide practice recommends validation of the HDM models with some other software that can be used for comparison of the forecasting results. The program package MATLAB is used in this case, as it enables for modelling of all the HDM models. A statistic validation of the results of the forecasts concerning the condition of the pavements in HDM with the on-field measuring results was also performed. This paper shall present the results of the validation of the coefficients of calibration of the deterioration models in HDM 4 on the Macedonian highways.

Natural analogues and radionuclide transport model validation

International Nuclear Information System (INIS)

Lever, D.A.

1987-08-01

In this paper, some possible roles for natural analogues are discussed from the point of view of those involved with the development of mathematical models for radionuclide transport and with the use of these models in repository safety assessments. The characteristic features of a safety assessment are outlined in order to address the questions of where natural analogues can be used to improve our understanding of the processes involved and where they can assist in validating the models that are used. Natural analogues have the potential to provide useful information about some critical processes, especially long-term chemical processes and migration rates. There is likely to be considerable uncertainty and ambiguity associated with the interpretation of natural analogues, and thus it is their general features which should be emphasized, and models with appropriate levels of sophistication should be used. Experience gained in modelling the Koongarra uranium deposit in northern Australia is drawn upon. (author)

Image decomposition as a tool for validating stress analysis models

Directory of Open Access Journals (Sweden)

Mottershead J.

2010-06-01

Full Text Available It is good practice to validate analytical and numerical models used in stress analysis for engineering design by comparison with measurements obtained from real components either in-service or in the laboratory. In reality, this critical step is often neglected or reduced to placing a single strain gage at the predicted hot-spot of stress. Modern techniques of optical analysis allow full-field maps of displacement, strain and, or stress to be obtained from real components with relative ease and at modest cost. However, validations continued to be performed only at predicted and, or observed hot-spots and most of the wealth of data is ignored. It is proposed that image decomposition methods, commonly employed in techniques such as fingerprinting and iris recognition, can be employed to validate stress analysis models by comparing all of the key features in the data from the experiment and the model. Image decomposition techniques such as Zernike moments and Fourier transforms have been used to decompose full-field distributions for strain generated from optical techniques such as digital image correlation and thermoelastic stress analysis as well as from analytical and numerical models by treating the strain distributions as images. The result of the decomposition is 101 to 102 image descriptors instead of the 105 or 106 pixels in the original data. As a consequence, it is relatively easy to make a statistical comparison of the image descriptors from the experiment and from the analytical/numerical model and to provide a quantitative assessment of the stress analysis.

Lesson "Balance in Nature

Science.gov (United States)

Chapanova, V.

2012-04-01

Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

Simple and Practical Efficiency Lessons

Science.gov (United States)

Kolpin, Van

2018-01-01

The derivation of conditions necessary for Pareto efficient production and exchange is a lesson frequently showcased in microeconomic theory textbooks. Traditional delivery of this lesson is, however, limited in its scope of application and can be unnecessarily convoluted. The author shows that the universe of application is greatly expanded and a…

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

Science.gov (United States)

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

2013-04-01

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

Using the CLEAN educational resource collection for building three-dimensional lessons to teach the climate system

Science.gov (United States)

Gold, A. U.; Sullivan, S. M.; Manning, C. L. B.; Ledley, T. S.; Youngman, E.; Taylor, J.; Niepold, F., III; Kirk, K.; Lockwood, J.; Bruckner, M. Z.; Fox, S.

2017-12-01

The impacts of climate change are a critical societal challenge of the 21st century. Educating students about the globally connected climate system is key in supporting the development of mitigation and adaptation strategies. Systems thinking is required for students to understand the complex, dynamic climate systems and the role that humans play within them. The interdisciplinary nature of climate science challenges educators, who often don't have formal training in climate science, to identify resources that are scientifically accurate before weaving them together into units that teach about the climate system. The Climate Literacy and Energy Awareness Network (CLEAN) supports this work by providing over 700 peer-reviewed, classroom-ready resources on climate and energy topics. The resource collection itself provide only limited instructional guidance, so educators need to weave the resources together to build multi-dimensional lessons that develop systems thinking skills. The Next Generation Science Standards (NGSS) science standards encourage educators to teach science in a 3-dimensional approach that trains students in systems thinking. The CLEAN project strives to help educators design NGSS-style, three-dimensional lessons about the climate system. Two approaches are currently being modeled on the CLEAN web portal. The first is described in the CLEAN NGSS "Get Started Guide" which follows a step-by-step process starting with the Disciplinary Core Idea and then interweaves the Cross-Cutting Concepts (CCC) and the Science and Engineering Practices (SEP) based on the teaching strategy chosen for the lesson or unit topic. The second model uses a climate topic as a starting place and the SEP as the guide through a four-step lesson sequence called "Earth Systems Investigations". Both models use CLEAN reviewed lessons as the core activity but provide the necessary framework for classroom implementation. Sample lessons that were developed following these two

High Turbidity Solis Clear Sky Model: Development and Validation

Directory of Open Access Journals (Sweden)

Pierre Ineichen

2018-03-01

Full Text Available The Solis clear sky model is a spectral scheme based on radiative transfer calculations and the Lambert–Beer relation. Its broadband version is a simplified fast analytical version; it is limited to broadband aerosol optical depths lower than 0.45, which is a weakness when applied in countries with very high turbidity such as China or India. In order to extend the use of the original simplified version of the model for high turbidity values, we developed a new version of the broadband Solis model based on radiative transfer calculations, valid for turbidity values up to 7, for the three components, global, beam, and diffuse, and for the four aerosol types defined by Shettle and Fenn. A validation of low turbidity data acquired in Geneva shows slightly better results than the previous version. On data acquired at sites presenting higher turbidity data, the bias stays within ±4% for the beam and the global irradiances, and the standard deviation around 5% for clean and stable condition data and around 12% for questionable data and variable sky conditions.

Construction and validation of detailed kinetic models for the combustion of gasoline surrogates; Construction et validation de modeles cinetiques detailles pour la combustion de melanges modeles des essences

Energy Technology Data Exchange (ETDEWEB)

Touchard, S.

2005-10-15

The irreversible reduction of oil resources, the CO{sub 2} emission control and the application of increasingly strict standards of pollutants emission lead the worldwide researchers to work to reduce the pollutants formation and to improve the engine yields, especially by using homogenous charge combustion of lean mixtures. The numerical simulation of fuel blends oxidation is an essential tool to study the influence of fuel formulation and motor conditions on auto-ignition and on pollutants emissions. The automatic generation helps to obtain detailed kinetic models, especially at low temperature, where the number of reactions quickly exceeds thousand. The main purpose of this study is the generation and the validation of detailed kinetic models for the oxidation of gasoline blends using the EXGAS software. This work has implied an improvement of computation rules for thermodynamic and kinetic data, those were validated by numerical simulation using CHEMKIN II softwares. A large part of this work has concerned the understanding of the low temperature oxidation chemistry of the C5 and larger alkenes. Low and high temperature mechanisms were proposed and validated for 1 pentene, 1-hexene, the binary mixtures containing 1 hexene/iso octane, 1 hexene/toluene, iso octane/toluene and the ternary mixture of 1 hexene/toluene/iso octane. Simulations were also done for propene, 1-butene and iso-octane with former models including the modifications proposed in this PhD work. If the generated models allowed us to simulate with a good agreement the auto-ignition delays of the studied molecules and blends, some uncertainties still remains for some reaction paths leading to the formation of cyclic products in the case of alkenes oxidation at low temperature. It would be also interesting to carry on this work for combustion models of gasoline blends at low temperature. (author)

Validation of an O-18 leaf water enrichment model

Energy Technology Data Exchange (ETDEWEB)

Jaeggi, M.; Saurer, M.; Siegwolf, R.

2002-03-01

The seasonal trend in {delta}{sup 18}O{sub ol} in leaf organic matter of spruce needles of mature trees could be modelled for two years. The seasonality was mainly explained by the {delta}{sup 18}O of top-soil water, whereas between years differences were due to variation in air humidity. Application of a third year's data set improved the correlation between modelled and measured {delta}{sup 18}O{sub ol} and thus validated our extended Dongmann model. (author)

Development and validation of logistic prognostic models by predefined SAS-macros

Directory of Open Access Journals (Sweden)

Ziegler, Christoph

2006-02-01

Full Text Available In medical decision making about therapies or diagnostic procedures in the treatment of patients the prognoses of the course or of the magnitude of diseases plays a relevant role. Beside of the subjective attitude of the clinician mathematical models can help in providing such prognoses. Such models are mostly multivariate regression models. In the case of a dichotomous outcome the logistic model will be applied as the standard model. In this paper we will describe SAS-macros for the development of such a model, for examination of the prognostic performance, and for model validation. The rational for this developmental approach of a prognostic modelling and the description of the macros can only given briefly in this paper. Much more details are given in. These 14 SAS-macros are a tool for setting up the whole process of deriving a prognostic model. Especially the possibility of validating the model by a standardized software tool gives an opportunity, which is not used in general in published prognostic models. Therefore, this can help to develop new models with good prognostic performance for use in medical applications.

Modeling and validation of existing VAV system components

Energy Technology Data Exchange (ETDEWEB)

Nassif, N.; Kajl, S.; Sabourin, R. [Ecole de Technologie Superieure, Montreal, PQ (Canada)

2004-07-01

The optimization of supervisory control strategies and local-loop controllers can improve the performance of HVAC (heating, ventilating, air-conditioning) systems. In this study, the component model of the fan, the damper and the cooling coil were developed and validated against monitored data of an existing variable air volume (VAV) system installed at Montreal's Ecole de Technologie Superieure. The measured variables that influence energy use in individual HVAC models included: (1) outdoor and return air temperature and relative humidity, (2) supply air and water temperatures, (3) zone airflow rates, (4) supply duct, outlet fan, mixing plenum static pressures, (5) fan speed, and (6) minimum and principal damper and cooling and heating coil valve positions. The additional variables that were considered, but not measured were: (1) fan and outdoor airflow rate, (2) inlet and outlet cooling coil relative humidity, and (3) liquid flow rate through the heating or cooling coils. The paper demonstrates the challenges of the validation process when monitored data of existing VAV systems are used. 7 refs., 11 figs.

Planning geometry lessons with learning platforms

DEFF Research Database (Denmark)

Tamborg, Andreas Lindenskov

mathematics teachers’ joint planning of a lesson in geometry with a learning platform called Meebook is analyzed using the instrumental approach. It is concluded that the interface in Meebook orients the teachers work toward what the students should do rather than what they should learn, although the latter......This paper investigates how mathematics teachers plan lessons with a recently implemented Danish learning platform designed to support teachers in planning lessons in line with a recent objective-oriented curriculum. Drawing on data from observations of and interviews with teachers, three...... is a key intention behind the implementation of the platform. It is also concluded that when the teachers succeed in using learning objectives actively in their planning, the objectives support the teachers in designing lessons that correspond with their intentions. The paper concludes with a discussion...

The Fernald Closure Project: Lessons Learned

International Nuclear Information System (INIS)

Murphy, Cornelius M.; Carr, Dennis

2008-01-01

For nearly 37 years, the U.S. Department of Energy site at Fernald - near Cincinnati, Ohio - produced 230,000 metric tons (250,000 short tons) of high-purity, low-enriched uranium for the U.S. Defense Program, generating more than 5.4 million metric tons (6 million short tons) of liquid and solid waste as it carried out its Cold War mission. The facility was shut down in 1989 and clean up began in 1992, when Fluor won the contract to clean up the site. Cleaning up Fernald and returning it to the people of Ohio was a $4.4 billion mega environmental-remediation project that was completed in October 2006. Project evolved through four phases: - Conducting remedial-investigation studies to determine the extent of damage to the environment and groundwater at, and adjacent to, the production facilities; - Selecting cleanup criteria - final end states that had to be met that protect human health and the environment; - Selecting and implementing the remedial actions to meet the cleanup goals; - Executing the work in a safe, compliant and cost-effective manner. In the early stages of the project, there were strained relationships - in fact total distrust - between the local community and the DOE as a result of aquifer contamination and potential health effects to the workers and local residents. To engage citizens and interested stakeholders groups in the decision-making process, the DOE and Fluor developed a public-participation strategy to open the channels of communication with the various parties: site leadership, technical staff and regulators. This approach proved invaluable to the success of the project, which has become a model for future environmental remediation projects. This paper will summarize the history and shares lessons learned: the completion of the uranium-production mission to the implementation of the Records of Decision defining the cleanup standards and the remedies achieved. Lessons learned fall into ten categories: - Regulatory approach with end

Masterwork Art Lesson: Kandinsky Watercolors.

Science.gov (United States)

LiPira, Michael

2003-01-01

Presents an art lesson used with sixth-grade students which also can be used with other grade levels. Explains that the artwork of Wassily Kandinsky served as inspiration for this lesson. Explains that the students learned about abstract art and used watercolors to create their own paintings in the style of Kandinsky. (CMK)

Bead Game Simulation. Lesson Plan.

Science.gov (United States)

Ripp, Ken

This lesson plan offers students the opportunity to participate in the three basic economic systems (market, command, and tradition). By working in each of the systems, students will internalize the fundamental values present in each system and will gain insights into the basic advantages and disadvantages of each system. The lesson plan provides…

Effects of Task Performance and Task Complexity on the Validity of Computational Models of Attention

NARCIS (Netherlands)

Koning, L. de; Maanen, P.P. van; Dongen, K. van

2008-01-01

Computational models of attention can be used as a component of decision support systems. For accurate support, a computational model of attention has to be valid and robust. The effects of task performance and task complexity on the validity of three different computational models of attention were

Implementing US Department of Energy lessons learned programs. Volume 2

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

The DOE Lessons Learned Handbook is a two-volume publication developed to supplement the DOE Lessons Learned Standard (DOE-STD-7501-95) with information that will organizations in developing or improving their lessons learned programs. Volume 1 includes greater detail than the Standard in areas such as identification and documentation of lessons learned; it also contains sections on specific processes such as training and performance measurement. Volume 2 (this document) contains examples of program documents developed by existing lessons learned programs as well as communications material, functional categories, transmittal documents, sources of professional and industry lessons learned, and frequently asked questions about the Lessons Learned List Service.

Temporal validation for landsat-based volume estimation model

Science.gov (United States)

Renaldo J. Arroyo; Emily B. Schultz; Thomas G. Matney; David L. Evans; Zhaofei Fan

2015-01-01

Satellite imagery can potentially reduce the costs and time associated with ground-based forest inventories; however, for satellite imagery to provide reliable forest inventory data, it must produce consistent results from one time period to the next. The objective of this study was to temporally validate a Landsat-based volume estimation model in a four county study...

Validation of PV-RPM Code in the System Advisor Model.

Energy Technology Data Exchange (ETDEWEB)

Klise, Geoffrey Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Freeman, Janine [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-01

This paper describes efforts made by Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) to validate the SNL developed PV Reliability Performance Model (PV - RPM) algorithm as implemented in the NREL System Advisor Model (SAM). The PV - RPM model is a library of functions that estimates component failure and repair in a photovoltaic system over a desired simulation period. The failure and repair distributions in this paper are probabilistic representations of component failure and repair based on data collected by SNL for a PV power plant operating in Arizona. The validation effort focuses on whether the failure and repair dist ributions used in the SAM implementation result in estimated failures that match the expected failures developed in the proof - of - concept implementation. Results indicate that the SAM implementation of PV - RPM provides the same results as the proof - of - concep t implementation, indicating the algorithms were reproduced successfully.

Deployable and Conformal Planar Micro-Devices: Design and Model Validation

Directory of Open Access Journals (Sweden)

Jinda Zhuang

2014-08-01

Full Text Available We report a design concept for a deployable planar microdevice and the modeling and experimental validation of its mechanical behavior. The device consists of foldable membranes that are suspended between flexible stems and actuated by push-pull wires. Such a deployable device can be introduced into a region of interest in its compact “collapsed” state and then deployed to conformally cover a large two-dimensional surface area for minimally invasive biomedical operations and other engineering applications. We develop and experimentally validate theoretical models based on the energy minimization approach to examine the conformality and figures of merit of the device. The experimental results obtained using model contact surfaces agree well with the prediction and quantitatively highlight the importance of the membrane bending modulus in controlling surface conformality. The present study establishes an early foundation for the mechanical design of this and related deployable planar microdevice concepts.

Modeling and validating HL7 FHIR profiles using semantic web Shape Expressions (ShEx).

Science.gov (United States)

Solbrig, Harold R; Prud'hommeaux, Eric; Grieve, Grahame; McKenzie, Lloyd; Mandel, Joshua C; Sharma, Deepak K; Jiang, Guoqian

2017-03-01

HL7 Fast Healthcare Interoperability Resources (FHIR) is an emerging open standard for the exchange of electronic healthcare information. FHIR resources are defined in a specialized modeling language. FHIR instances can currently be represented in either XML or JSON. The FHIR and Semantic Web communities are developing a third FHIR instance representation format in Resource Description Framework (RDF). Shape Expressions (ShEx), a formal RDF data constraint language, is a candidate for describing and validating the FHIR RDF representation. Create a FHIR to ShEx model transformation and assess its ability to describe and validate FHIR RDF data. We created the methods and tools that generate the ShEx schemas modeling the FHIR to RDF specification being developed by HL7 ITS/W3C RDF Task Force, and evaluated the applicability of ShEx in the description and validation of FHIR to RDF transformations. The ShEx models contributed significantly to workgroup consensus. Algorithmic transformations from the FHIR model to ShEx schemas and FHIR example data to RDF transformations were incorporated into the FHIR build process. ShEx schemas representing 109 FHIR resources were used to validate 511 FHIR RDF data examples from the Standards for Trial Use (STU 3) Ballot version. We were able to uncover unresolved issues in the FHIR to RDF specification and detect 10 types of errors and root causes in the actual implementation. The FHIR ShEx representations have been included in the official FHIR web pages for the STU 3 Ballot version since September 2016. ShEx can be used to define and validate the syntax of a FHIR resource, which is complementary to the use of RDF Schema (RDFS) and Web Ontology Language (OWL) for semantic validation. ShEx proved useful for describing a standard model of FHIR RDF data. The combination of a formal model and a succinct format enabled comprehensive review and automated validation. Copyright © 2017 Elsevier Inc. All rights reserved.

Physically active academic lessons in elementary children.

Science.gov (United States)

Bartholomew, John B; Jowers, Esbelle M

2011-06-01

Although schools are an ideal location to conduct interventions that target children, the emphasis on standardized testing makes it difficult to implement interventions that do not directly support academic instruction. In response, physically active academic lessons have been developed as a strategy to increase physical activity while also addressing core educational goals. Texas I-CAN! is one incarnation of this approach. We will review the on-going research on the impact of these active lessons on: teacher implementation, child step count, child attention control, and academic performance. The collected studies support the impact of physically active academic lessons on each area of interest. If these data can be replicated, it suggests that teachers might find these lessons of benefit to their primary role as educators, which should ease dissemination of these and other physically active lessons in elementary schools. Copyright © 2011 Elsevier Inc. All rights reserved.

Validation of a tuber blight (Phytophthora infestans) prediction model

Science.gov (United States)

Potato tuber blight caused by Phytophthora infestans accounts for significant losses in storage. There is limited published quantitative data on predicting tuber blight. We validated a tuber blight prediction model developed in New York with cultivars Allegany, NY 101, and Katahdin using independent...

Technical Note: Calibration and validation of geophysical observation models

NARCIS (Netherlands)

Salama, M.S.; van der Velde, R.; van der Woerd, H.J.; Kromkamp, J.C.; Philippart, C.J.M.; Joseph, A.T.; O'Neill, P.E.; Lang, R.H.; Gish, T.; Werdell, P.J.; Su, Z.

2012-01-01

We present a method to calibrate and validate observational models that interrelate remotely sensed energy fluxes to geophysical variables of land and water surfaces. Coincident sets of remote sensing observation of visible and microwave radiations and geophysical data are assembled and subdivided

Quantification of Dynamic Model Validation Metrics Using Uncertainty Propagation from Requirements

Science.gov (United States)

Brown, Andrew M.; Peck, Jeffrey A.; Stewart, Eric C.

2018-01-01

The Space Launch System, NASA's new large launch vehicle for long range space exploration, is presently in the final design and construction phases, with the first launch scheduled for 2019. A dynamic model of the system has been created and is critical for calculation of interface loads and natural frequencies and mode shapes for guidance, navigation, and control (GNC). Because of the program and schedule constraints, a single modal test of the SLS will be performed while bolted down to the Mobile Launch Pad just before the first launch. A Monte Carlo and optimization scheme will be performed to create thousands of possible models based on given dispersions in model properties and to determine which model best fits the natural frequencies and mode shapes from modal test. However, the question still remains as to whether this model is acceptable for the loads and GNC requirements. An uncertainty propagation and quantification (UP and UQ) technique to develop a quantitative set of validation metrics that is based on the flight requirements has therefore been developed and is discussed in this paper. There has been considerable research on UQ and UP and validation in the literature, but very little on propagating the uncertainties from requirements, so most validation metrics are "rules-of-thumb;" this research seeks to come up with more reason-based metrics. One of the main assumptions used to achieve this task is that the uncertainty in the modeling of the fixed boundary condition is accurate, so therefore that same uncertainty can be used in propagating the fixed-test configuration to the free-free actual configuration. The second main technique applied here is the usage of the limit-state formulation to quantify the final probabilistic parameters and to compare them with the requirements. These techniques are explored with a simple lumped spring-mass system and a simplified SLS model. When completed, it is anticipated that this requirements-based validation

Heat Transfer Modeling and Validation for Optically Thick Alumina Fibrous Insulation

Science.gov (United States)

Daryabeigi, Kamran

2009-01-01

Combined radiation/conduction heat transfer through unbonded alumina fibrous insulation was modeled using the diffusion approximation for modeling the radiation component of heat transfer in the optically thick insulation. The validity of the heat transfer model was investigated by comparison to previously reported experimental effective thermal conductivity data over the insulation density range of 24 to 96 kg/cu m, with a pressure range of 0.001 to 750 torr (0.1 to 101.3 x 10(exp 3) Pa), and test sample hot side temperature range of 530 to 1360 K. The model was further validated by comparison to thermal conductivity measurements using the transient step heating technique on an insulation sample at a density of 144 kg/cu m over a pressure range of 0.001 to 760 torr, and temperature range of 290 to 1090 K.

Alternative Energy Lessons in Scotland

Science.gov (United States)

Boyle, Julie

2010-05-01

In Scotland the new science curriculum for pupils aged 12 to 15 shall include the following outcomes: "Using my knowledge and understanding, I can express an informed view on a national or global environmental issue;" "I have participated in constructing a model to harness a renewable source of energy and can investigate how to optimise the output;" and "I can discuss why it is important to me and to the future of the world that alternatives to fossil fuels are developed." There will be an emphasis on creating lessons that will nurture responsible citizens, improve pupil engagement and allow students to develop their team working skills. To help teachers plan lessons to address this, the Scottish Schools Equipment Research Centre and Edinburgh University made teaching materials on four renewable energy resources. This poster describes how their suggested activities on solar cells, wind turbines, hydroelectric power stations and wave power were used in science lessons with twelve year old students. After an initial class discussion based on issues related to climate change and diminishing fossil fuel supplies, a workshop activity was carried out in three stages. The students were issued with a fact sheet about one of four imaginary islands (Skisdale, Cloudy Island, Surfsville and Sun City) and they were asked to work in teams to choose the most suitable method of generating electricity for their island. Issues such as costs, where it will be sited and environmental implications were considered. They were then asked to conduct practical activities by constructing and testing models for these forms of renewable energy. To conclude, they presented their proposal to the rest of the class with reasoned explanations. The kits used in the lessons can be purchased from Anderson Scientific (sales@andersonscientific.co.uk). The solar cells were simply connected to a voltmeter. The wind and hydroelectric groups used the same basic equipment. This was made using a small water

Lesson Study and History Education

Science.gov (United States)

Halvorsen, Anne-Lise; Kesler Lund, Alisa

2013-01-01

This article examines the experiences of a group of fifth-grade teachers who used lesson study, a teacher-driven form of professional development, to teach history in a project supported by a Teaching American History Grant. The project addressed the following questions: What does a lesson study cycle for history education look like? What…

Validating a model that predicts daily growth and feed quality of New Zealand dairy pastures.

Science.gov (United States)

Woodward, S J

2001-09-01

The Pasture Quality (PQ) model is a simple, mechanistic, dynamical system model that was designed to capture the essential biological processes in grazed grass-clover pasture, and to be optimised to derive improved grazing strategies for New Zealand dairy farms. While the individual processes represented in the model (photosynthesis, tissue growth, flowering, leaf death, decomposition, worms) were based on experimental data, this did not guarantee that the assembled model would accurately predict the behaviour of the system as a whole (i.e., pasture growth and quality). Validation of the whole model was thus a priority, since any strategy derived from the model could impact a farm business in the order of thousands of dollars per annum if adopted. This paper describes the process of defining performance criteria for the model, obtaining suitable data to test the model, and carrying out the validation analysis. The validation process highlighted a number of weaknesses in the model, which will lead to the model being improved. As a result, the model's utility will be enhanced. Furthermore, validation was found to have an unexpected additional benefit, in that despite the model's poor initial performance, support was generated for the model among field scientists involved in the wider project.

Evaluation of Validity and Reliability for Hierarchical Scales Using Latent Variable Modeling

Science.gov (United States)

Raykov, Tenko; Marcoulides, George A.

2012-01-01

A latent variable modeling method is outlined, which accomplishes estimation of criterion validity and reliability for a multicomponent measuring instrument with hierarchical structure. The approach provides point and interval estimates for the scale criterion validity and reliability coefficients, and can also be used for testing composite or…

Our reflections and lessons from the Fukushima Nuclear Accident

International Nuclear Information System (INIS)

Matsuoka, Takeshi; Sawada, Takashi; Yagawa, Genki

2017-01-01

In order to investigate the cause of the accident that began on March 11, 2011 at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station, the Science Council of Japan set an investigation committee, the 'Sub-Committee on Fukushima Nuclear Accident (SCFNA)' under the Comprehensive Synthetic Engineering Committee. The committee has published a record entitled 'Reflections and Lessons from the Fukushima Nuclear Accident, (1st report)'. There are still many items about the accident for which the details are not clear. It is important to discuss the reasons why the severe accident could not be prevented and the possibilities that there might have been other proper operations and accident management to prevent or lessen the severity of the accident than those adopted at the time. SCFNA decided to continue its investigation by setting up our working group called the 'Working Group on Fukushima Nuclear Accident'. Our working group have published 'Reflection and Lessons from the Fukushima Nuclear Accident (2nd Report)'. We investigated the issues of specific units. Unit 1 were validity of the operation of the isolation condenser, whether or not a loss of coolant accident occurred due to a failure of the cooling piping system by the seismic ground motion, and the cause of the loss of the emergency AC power supply, Unit 2 was the reason why a large amount of radioactive materials was emitted to the environment although the reactor building did not explode, Unit 3 was the reasons why the operator stopped running the high pressure coolant injection system, and Units 1 to 3 was validity of the venting operation. These items were considered to be the key issues in these units that would have prevented progression to the severe accident. (author)