Transtheoretical Model Constructs for Physical Activity Behavior are Invariant across Time among Ethnically Diverse Adults in Hawaii

PubMed Central

Nigg, Claudio R; Motl, Robert W; Horwath, Caroline; Dishman, Rod K

2012-01-01

Objectives Physical activity (PA) research applying the Transtheoretical Model (TTM) to examine group differences and/or change over time requires preliminary evidence of factorial validity and invariance. The current study examined the factorial validity and longitudinal invariance of TTM constructs recently revised for PA. Method Participants from an ethnically diverse sample in Hawaii (N=700) completed questionnaires capturing each TTM construct. Results Factorial validity was confirmed for each construct using confirmatory factor analysis with full-information maximum likelihood. Longitudinal invariance was evidenced across a shorter (3-month) and longer (6-month) time period via nested model comparisons. Conclusions The questionnaires for each validated TTM construct are provided, and can now be generalized across similar subgroups and time points. Further validation of the provided measures is suggested in additional populations and across extended time points. PMID:22778669

Modeling the cross-sectional relationships between religion, physical health, social support, and depressive symptoms.

PubMed

Koenig, H G; Hays, J C; George, L K; Blazer, D G; Larson, D B; Landerman, L R

1997-01-01

The authors examined models of the relationships between religious activities, physical health, social support, and depressive symptoms in a sample of 4,000 persons age 65 and over. Religious activity was examined first as a single composite construct and then split into three component variables that were examined individually. Religious activity as a single construct was correlated with both social support and good physical health but was unrelated to depression. Split into the three components, model fit was significantly increased. Frequency of church attendance was positively related to physical health and negatively related to depression, but was surprisingly unrelated to social support. Frequent churchgoers were about half as likely to be depressed. Private prayer/Bible reading was negatively correlated with physical health and positively correlated with social support, but unrelated to depression. Religious TV/radio listening was unrelated to social support, negatively related to good physical health, and, unexpectedly, positively associated with depression.

Construct Validity Evidence for Single-Response Items to Estimate Physical Activity Levels in Large Sample Studies

ERIC Educational Resources Information Center

Jackson, Allen W.; Morrow, James R., Jr.; Bowles, Heather R.; FitzGerald, Shannon J.; Blair, Steven N.

2007-01-01

Valid measurement of physical activity is important for studying the risks for morbidity and mortality. The purpose of this study was to examine evidence of construct validity of two similar single-response items assessing physical activity via self-report. Both items are based on the stages of change model. The sample was 687 participants (men =…

USE OF TRANS-CONTEXTUAL MODEL-BASED PHYSICAL ACTIVITY COURSE IN DEVELOPING LEISURE-TIME PHYSICAL ACTIVITY BEHAVIOR OF UNIVERSITY STUDENTS.

PubMed

Müftüler, Mine; İnce, Mustafa Levent

2015-08-01

This study examined how a physical activity course based on the Trans-Contextual Model affected the variables of perceived autonomy support, autonomous motivation, determinants of leisure-time physical activity behavior, basic psychological needs satisfaction, and leisure-time physical activity behaviors. The participants were 70 Turkish university students (M age=23.3 yr., SD=3.2). A pre-test-post-test control group design was constructed. Initially, the participants were randomly assigned into an experimental (n=35) and a control (n=35) group. The experimental group followed a 12 wk. trans-contextual model-based intervention. The participants were pre- and post-tested in terms of Trans-Contextual Model constructs and of self-reported leisure-time physical activity behaviors. Multivariate analyses showed significant increases over the 12 wk. period for perceived autonomy support from instructor and peers, autonomous motivation in leisure-time physical activity setting, positive intention and perceived behavioral control over leisure-time physical activity behavior, more fulfillment of psychological needs, and more engagement in leisure-time physical activity behavior in the experimental group. These results indicated that the intervention was effective in developing leisure-time physical activity and indicated that the Trans-Contextual Model is a useful way to conceptualize these relationships.

An analysis of the DuPage County Regional Office of Education physics exam

NASA Astrophysics Data System (ADS)

Muehsler, Hans

In 2009, the DuPage County Regional Office of Education (ROE) tasked volunteer physics teachers with creating a basic skills physics exam reflecting what the participants valued and shared in common across curricula. Mechanics, electricity & magnetism (E&M), and wave phenomena emerged as the primary constructs. The resulting exam was intended for first-exposure physics students. The most recently completed version was psychometrically assessed for unidimensionality within the constructs using a robust WLS structural equation model and for reliability. An item analysis using a 3-PL IRT model was performed on the mechanics items and a 2-PL IRT model was performed on the E&M and waves items; a distractor analysis was also performed on all items. Lastly, differential item functioning (DIF) and differential test functioning (DTF) analyses, using the Mantel-Haenszel procedure, were performed using gender, ethnicity, year in school, ELL, physics level, and math level as groupings.

Leveraging a Relationship with Biology to Expand a Relationship with Physics

ERIC Educational Resources Information Center

Sawtelle, Vashti; Turpen, Chandra

2016-01-01

This work examines how experiences in one disciplinary domain (biology) can impact the relationship a student builds with another domain (physics). We present a model for disciplinary relationships using the constructs of identity, affect, and epistemology. With these constructs we examine an ethnographic case study of a student who experienced a…

Model-Based Reasoning in the Physics Laboratory: Framework and Initial Results

ERIC Educational Resources Information Center

Zwickl, Benjamin M.; Hu, Dehui; Finkelstein, Noah; Lewandowski, H. J.

2015-01-01

We review and extend existing frameworks on modeling to develop a new framework that describes model-based reasoning in introductory and upper-division physics laboratories. Constructing and using models are core scientific practices that have gained significant attention within K-12 and higher education. Although modeling is a broadly applicable…

The effectiveness of CPI model to improve positive attitude toward science (PATS) for pre-service physics teacher

NASA Astrophysics Data System (ADS)

Sunarti, T.; Wasis; Madlazim; Suyidno; Prahani, B. K.

2018-03-01

In the previous research, learning material based Construction, Production, and Implementation (CPI) model has been developed to improve scientific literacy and positive attitude toward science for pre-service physics teacher. CPI model has 4 phases, included: 1) Motivation; 2) Construction (Cycle I); 3) Production (Cycle II); and 4) Evaluation. This research is aimed to analyze the effectiveness of CPI model towards the improvement Positive Attitude toward Science (PATS) for pre-service physics teacher. This research used one group pre-test and post-test design on 160 pre-service physics teacher divided into 4 groups at Lambung Mangkurat University and Surabaya State University (Indonesia), academic year 2016/2017. Data collection was conducted through questioner, observation, and interview. Positive attitude toward science for pre-service physics teacher measurement were conducted through Positive Attitude toward Science Evaluation Sheet (PATSES). The data analysis technique was done by using Wilcoxon test and n-gain. The results showed that there was a significant increase in positive attitude toward science for pre-service physics teacher at α = 5%, with n-gain average of high category. Thus, the CPI model is effective for improving positive attitude toward science for pre-service physics teacher.

Construct and test scale model box culvert design project.

DOT National Transportation Integrated Search

2010-11-01

The research team at the University of New Mexicos (UNM) hydraulics lab designed, constructed, and : tested a 1:20 scale physical model of a proposed culvert in Jemez Springs, New Mexico. The culvert : design was developed by the New Mexico Depart...

Phenomenological Modeling of Infrared Sources: Recent Advances

NASA Technical Reports Server (NTRS)

Leung, Chun Ming; Kwok, Sun (Editor)

1993-01-01

Infrared observations from planned space facilities (e.g., ISO (Infrared Space Observatory), SIRTF (Space Infrared Telescope Facility)) will yield a large and uniform sample of high-quality data from both photometric and spectroscopic measurements. To maximize the scientific returns of these space missions, complementary theoretical studies must be undertaken to interpret these observations. A crucial step in such studies is the construction of phenomenological models in which we parameterize the observed radiation characteristics in terms of the physical source properties. In the last decade, models with increasing degree of physical realism (in terms of grain properties, physical processes, and source geometry) have been constructed for infrared sources. Here we review current capabilities available in the phenomenological modeling of infrared sources and discuss briefly directions for future research in this area.

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

NASA Astrophysics Data System (ADS)

Limatahu, I.; Sutoyo, S.; 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.

Identifying Multiple Levels of Discussion-Based Teaching Strategies for Constructing Scientific Models

ERIC Educational Resources Information Center

Williams, Grant; Clement, John

2015-01-01

This study sought to identify specific types of discussion-based strategies that two successful high school physics teachers using a model-based approach utilized in attempting to foster students' construction of explanatory models for scientific concepts. We found evidence that, in addition to previously documented dialogical strategies that…

Discrete Velocity Models for Polyatomic Molecules Without Nonphysical Collision Invariants

NASA Astrophysics Data System (ADS)

Bernhoff, Niclas

2018-05-01

An important aspect of constructing discrete velocity models (DVMs) for the Boltzmann equation is to obtain the right number of collision invariants. Unlike for the Boltzmann equation, for DVMs there can appear extra collision invariants, so called spurious collision invariants, in plus to the physical ones. A DVM with only physical collision invariants, and hence, without spurious ones, is called normal. The construction of such normal DVMs has been studied a lot in the literature for single species, but also for binary mixtures and recently extensively for multicomponent mixtures. In this paper, we address ways of constructing normal DVMs for polyatomic molecules (here represented by that each molecule has an internal energy, to account for non-translational energies, which can change during collisions), under the assumption that the set of allowed internal energies are finite. We present general algorithms for constructing such models, but we also give concrete examples of such constructions. This approach can also be combined with similar constructions of multicomponent mixtures to obtain multicomponent mixtures with polyatomic molecules, which is also briefly outlined. Then also, chemical reactions can be added.

Assessment of chevron dikes for the enhancement of physical-aquatic habitat within the Middle Mississippi River, USA

NASA Astrophysics Data System (ADS)

Remo, Jonathan W. F.; Khanal, Anish; Pinter, Nicholas

2013-09-01

Blunt-nosed chevron dikes, a new invention now being widely constructed on the Middle Mississippi River (MMR), have been justified as a tool for enhancing physical-aquatic habitat. Chevron dikes were initially designed to concentrate flow, induce channel scour, and thus facilitate river navigation. More recently, these structures have been justified, in part, for promoting habitat heterogeneity. The ability of chevrons to create and diversify physical-aquatic habitat, however, has not been empirically evaluated. To assess the ability of chevrons to create and diversify physical-aquatic habitat, we compiled hydrologic and geospatial data for three channel reference conditions along a 2.0 km (∼140 ha) reach of the MMR where three chevrons were constructed in late 2007. We used the hydrologic and hydraulic data to construct detailed 2-D hydrodynamic models for three reference condition: historic (circa 1890), pre-chevron, and post-chevron channel conditions. These models documented changes in depths and flow dynamics for a wide range of in-channel discharges. Depth-velocity habitat classes were used to assess change in physical-aquatic habitat patches and spatial statistical tools in order to evaluate the reach-scale habitat patch diversity. Comparisons of pre- and post-chevron conditions revealed increases in deep to very deep (>3.0 m) areas of slow moving (<0.6 m/s) water downstream of these structures under emergent flow conditions (⩽1.5 × mean annual flow [MAF]). Chevron construction added up to 7.6 ha of potential over-wintering habitat (deep [>3.0 m], low velocity [<0.6 m/s]). Chevron construction also created some (0.8-3.8 ha) shallow-water habitat (0-1.5 m depth with a 0-0.6 m/s velocity) for flows ⩽2.0 × MAF and contributed to an 8-35% increase in physical-aquatic-habitat diversity compared to pre-chevron channel conditions. However, modeling of the historic reference condition (less engineered channel, circa 1890) revealed that the historical physical-aquatic-habitat mosaic consisted of a wider and shallower channel with: 45-390% more shallow-water habitat (2.4-11.0 ha) and 22-83% more physical-aquatic-habitat diversity, but little over-wintering habitat (<0.4 ha). Thus, while chevron construction increased over-wintering habitat, shallow-water habitat, and physical-aquatic-habitat diversity relative to the pre-chevron channel condition, these types of physical-aquatic habitat are different from what was historically found along this reach. Constructing chevrons dikes, or other dike-like structures in the river channel, can change the physical-aquatic habitat patch mosaic and likely contribute to small increases in physical-aquatic-habitat heterogeneity. However, differences in the types, quantity, and diversity of physical-aquatic-habitat patches created by chevron dikes in comparison to the physical-aquatic-habitat patch mosaic of historic channel underscore the need for additional research to determine which physical-aquatic-habitat patches are critical for the recovery of endangered or threatened aquatic organisms.

Developing a Psychometric Instrument to Measure Physical Education Teachers' Job Demands and Resources.

PubMed

Zhang, Tan; Chen, Ang

2017-01-01

Based on the job demands-resources model, the study developed and validated an instrument that measures physical education teachers' job demands-resources perception. Expert review established content validity with the average item rating of 3.6/5.0. Construct validity and reliability were determined with a teacher sample ( n = 397). Exploratory factor analysis established a five-dimension construct structure matching the theoretical construct deliberated in the literature. The composite reliability scores for the five dimensions range from .68 to .83. Validity coefficients (intraclass correlational coefficients) are .69 for job resources items and .82 for job demands items. Inter-scale correlational coefficients range from -.32 to .47. Confirmatory factor analysis confirmed the construct validity with high dimensional factor loadings (ranging from .47 to .84 for job resources scale and from .50 to .85 for job demands scale) and adequate model fit indexes (root mean square error of approximation = .06). The instrument provides a tool to measure physical education teachers' perception of their working environment.

Developing a Psychometric Instrument to Measure Physical Education Teachers’ Job Demands and Resources

PubMed Central

Zhang, Tan; Chen, Ang

2017-01-01

Based on the job demands–resources model, the study developed and validated an instrument that measures physical education teachers’ job demands–resources perception. Expert review established content validity with the average item rating of 3.6/5.0. Construct validity and reliability were determined with a teacher sample (n = 397). Exploratory factor analysis established a five-dimension construct structure matching the theoretical construct deliberated in the literature. The composite reliability scores for the five dimensions range from .68 to .83. Validity coefficients (intraclass correlational coefficients) are .69 for job resources items and .82 for job demands items. Inter-scale correlational coefficients range from −.32 to .47. Confirmatory factor analysis confirmed the construct validity with high dimensional factor loadings (ranging from .47 to .84 for job resources scale and from .50 to .85 for job demands scale) and adequate model fit indexes (root mean square error of approximation = .06). The instrument provides a tool to measure physical education teachers’ perception of their working environment. PMID:29200808

Meta-Modeling: A Knowledge-Based Approach to Facilitating Model Construction and Reuse

NASA Technical Reports Server (NTRS)

Keller, Richard M.; Dungan, Jennifer L.

1997-01-01

In this paper, we introduce a new modeling approach called meta-modeling and illustrate its practical applicability to the construction of physically-based ecosystem process models. As a critical adjunct to modeling codes meta-modeling requires explicit specification of certain background information related to the construction and conceptual underpinnings of a model. This information formalizes the heretofore tacit relationship between the mathematical modeling code and the underlying real-world phenomena being investigated, and gives insight into the process by which the model was constructed. We show how the explicit availability of such information can make models more understandable and reusable and less subject to misinterpretation. In particular, background information enables potential users to better interpret an implemented ecosystem model without direct assistance from the model author. Additionally, we show how the discipline involved in specifying background information leads to improved management of model complexity and fewer implementation errors. We illustrate the meta-modeling approach in the context of the Scientists' Intelligent Graphical Modeling Assistant (SIGMA) a new model construction environment. As the user constructs a model using SIGMA the system adds appropriate background information that ties the executable model to the underlying physical phenomena under investigation. Not only does this information improve the understandability of the final model it also serves to reduce the overall time and programming expertise necessary to initially build and subsequently modify models. Furthermore, SIGMA's use of background knowledge helps eliminate coding errors resulting from scientific and dimensional inconsistencies that are otherwise difficult to avoid when building complex models. As a. demonstration of SIGMA's utility, the system was used to reimplement and extend a well-known forest ecosystem dynamics model: Forest-BGC.

Influence of fatigue on construction workers’ physical and cognitive function

PubMed Central

Zhang, M.; Murphy, L. A.; Fang, D.

2015-01-01

Background Despite scientific evidence linking workers’ fatigue to occupational safety (due to impaired physical or cognitive function), little is known about this relationship in construction workers. Aims To assess the association between construction workers’ reported fatigue and their perceived difficulties with physical and cognitive functions. Methods Using data from a convenience sample of US construction workers participating in the 2010–11 National Health Interview Survey two multivariate weighted logistic regression models were built to predict difficulty with physical and with cognitive functions associated with workers’ reported fatigue, while controlling for age, smoking status, alcohol consumption status, sleep hygiene, psychological distress and arthritis status. Results Of 606 construction workers surveyed, 49% reported being ‘tired some days’ in the past 3 months and 10% reported ‘tired most days or every day’. Compared with those feeling ‘never tired’, workers who felt ‘tired some days’ were significantly more likely to report difficulty with physical function (adjusted odds ratio [AOR] = 2.03; 95% confidence interval [CI] 1.17–3.51) and cognitive function (AOR = 2.27; 95% CI 1.06–4.88) after controlling for potential confounders. Conclusions Our results suggest an association between reported fatigue and experiencing difficulties with physical and cognitive functions in construction workers. PMID:25701835

Structural Stability Monitoring of a Physical Model Test on an Underground Cavern Group during Deep Excavations Using FBG Sensors.

PubMed

Li, Yong; Wang, Hanpeng; Zhu, Weishen; Li, Shucai; Liu, Jian

2015-08-31

Fiber Bragg Grating (FBG) sensors are comprehensively recognized as a structural stability monitoring device for all kinds of geo-materials by either embedding into or bonding onto the structural entities. The physical model in geotechnical engineering, which could accurately simulate the construction processes and the effects on the stability of underground caverns on the basis of satisfying the similarity principles, is an actual physical entity. Using a physical model test of underground caverns in Shuangjiangkou Hydropower Station, FBG sensors were used to determine how to model the small displacements of some key monitoring points in the large-scale physical model during excavation. In the process of building the test specimen, it is most successful to embed FBG sensors in the physical model through making an opening and adding some quick-set silicon. The experimental results show that the FBG sensor has higher measuring accuracy than other conventional sensors like electrical resistance strain gages and extensometers. The experimental results are also in good agreement with the numerical simulation results. In conclusion, FBG sensors could effectively measure small displacements of monitoring points in the whole process of the physical model test. The experimental results reveal the deformation and failure characteristics of the surrounding rock mass and make some guidance for the in situ engineering construction.

Structural Stability Monitoring of a Physical Model Test on an Underground Cavern Group during Deep Excavations Using FBG Sensors

PubMed Central

Li, Yong; Wang, Hanpeng; Zhu, Weishen; Li, Shucai; Liu, Jian

2015-01-01

Fiber Bragg Grating (FBG) sensors are comprehensively recognized as a structural stability monitoring device for all kinds of geo-materials by either embedding into or bonding onto the structural entities. The physical model in geotechnical engineering, which could accurately simulate the construction processes and the effects on the stability of underground caverns on the basis of satisfying the similarity principles, is an actual physical entity. Using a physical model test of underground caverns in Shuangjiangkou Hydropower Station, FBG sensors were used to determine how to model the small displacements of some key monitoring points in the large-scale physical model during excavation. In the process of building the test specimen, it is most successful to embed FBG sensors in the physical model through making an opening and adding some quick-set silicon. The experimental results show that the FBG sensor has higher measuring accuracy than other conventional sensors like electrical resistance strain gages and extensometers. The experimental results are also in good agreement with the numerical simulation results. In conclusion, FBG sensors could effectively measure small displacements of monitoring points in the whole process of the physical model test. The experimental results reveal the deformation and failure characteristics of the surrounding rock mass and make some guidance for the in situ engineering construction. PMID:26404287

Reduced-Order Modeling: New Approaches for Computational Physics

NASA Technical Reports Server (NTRS)

Beran, Philip S.; Silva, Walter A.

2001-01-01

In this paper, we review the development of new reduced-order modeling techniques and discuss their applicability to various problems in computational physics. Emphasis is given to methods ba'sed on Volterra series representations and the proper orthogonal decomposition. Results are reported for different nonlinear systems to provide clear examples of the construction and use of reduced-order models, particularly in the multi-disciplinary field of computational aeroelasticity. Unsteady aerodynamic and aeroelastic behaviors of two- dimensional and three-dimensional geometries are described. Large increases in computational efficiency are obtained through the use of reduced-order models, thereby justifying the initial computational expense of constructing these models and inotivatim,- their use for multi-disciplinary design analysis.

Advanced Machine Learning Emulators of Radiative Transfer Models

NASA Astrophysics Data System (ADS)

Camps-Valls, G.; Verrelst, J.; Martino, L.; Vicent, J.

2017-12-01

Physically-based model inversion methodologies are based on physical laws and established cause-effect relationships. A plethora of remote sensing applications rely on the physical inversion of a Radiative Transfer Model (RTM), which lead to physically meaningful bio-geo-physical parameter estimates. The process is however computationally expensive, needs expert knowledge for both the selection of the RTM, its parametrization and the the look-up table generation, as well as its inversion. Mimicking complex codes with statistical nonlinear machine learning algorithms has become the natural alternative very recently. Emulators are statistical constructs able to approximate the RTM, although at a fraction of the computational cost, providing an estimation of uncertainty, and estimations of the gradient or finite integral forms. We review the field and recent advances of emulation of RTMs with machine learning models. We posit Gaussian processes (GPs) as the proper framework to tackle the problem. Furthermore, we introduce an automatic methodology to construct emulators for costly RTMs. The Automatic Gaussian Process Emulator (AGAPE) methodology combines the interpolation capabilities of GPs with the accurate design of an acquisition function that favours sampling in low density regions and flatness of the interpolation function. We illustrate the good capabilities of our emulators in toy examples, leaf and canopy levels PROSPECT and PROSAIL RTMs, and for the construction of an optimal look-up-table for atmospheric correction based on MODTRAN5.

Apparatus for Teaching Physics.

ERIC Educational Resources Information Center

Minnix, Richard B., Ed.; Carpenter, D. Rae, Jr., Ed.

1983-01-01

Describes four body-lever models (biceps, triceps, back lever when lifting, foot lever and Achilles tendon muscle) used in noncalculus physics courses. Instructions for constructing the wooden models are provided. Also describes an improvement on a centripetal-force apparatus so that it is easier to operate. (JN)

Infrasound Predictions Using the Weather Research and Forecasting Model: Atmospheric Green's Functions for the Source Physics Experiments 1-6.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poppeliers, Christian; Aur, Katherine Anderson; Preston, Leiph

This report shows the results of constructing predictive atmospheric models for the Source Physics Experiments 1-6. Historic atmospheric data are combined with topography to construct an atmo- spheric model that corresponds to the predicted (or actual) time of a given SPE event. The models are ultimately used to construct atmospheric Green's functions to be used for subsequent analysis. We present three atmospheric models for each SPE event: an average model based on ten one- hour snap shots of the atmosphere and two extrema models corresponding to the warmest, coolest, windiest, etc. atmospheric snap shots. The atmospheric snap shots consist ofmore » wind, temperature, and pressure profiles of the atmosphere for a one-hour time window centered at the time of the predicted SPE event, as well as nine additional snap shots for each of the nine preceding years, centered at the time and day of the SPE event.« less

How to Make a Good Animation: A Grounded Cognition Model of How Visual Representation Design Affects the Construction of Abstract Physics Knowledge

ERIC Educational Resources Information Center

Chen, Zhongzhou; Gladding, Gary

2014-01-01

Visual representations play a critical role in teaching physics. However, since we do not have a satisfactory understanding of how visual perception impacts the construction of abstract knowledge, most visual representations used in instructions are either created based on existing conventions or designed according to the instructor's intuition,…

Teachers' Views on the Construction, Management and Delivery of an Externally Prescribed Physical Education Curriculum: Higher Grade Physical Education

ERIC Educational Resources Information Center

MacPhail, Ann

2007-01-01

Background: The level of influence teachers have over changing developments in curricula to suit their individual schools is not matched by the influence they possess in the development of such curricula outside of the school context. Bernstein's model of the social construction of pedagogic discourse allows examination of the development,…

On the physical Hilbert space of loop quantum cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noui, Karim; Perez, Alejandro; Vandersloot, Kevin

2005-02-15

In this paper we present a model of Riemannian loop quantum cosmology with a self-adjoint quantum scalar constraint. The physical Hilbert space is constructed using refined algebraic quantization. When matter is included in the form of a cosmological constant, the model is exactly solvable and we show explicitly that the physical Hilbert space is separable, consisting of a single physical state. We extend the model to the Lorentzian sector and discuss important implications for standard loop quantum cosmology.

Construct Validity of Selected Measures of Physical Activity Beliefs and Motives in Fifth and Sixth Grade Boys and Girls

PubMed Central

Saunders, Ruth P.; McIver, Kerry L.; Dowda, Marsha; Pate, Russell R.

2013-01-01

Objective Scales used to measure selected social-cognitive beliefs and motives for physical activity were tested among boys and girls. Methods Covariance modeling was applied to responses obtained from large multi-ethnic samples of students in the fifth and sixth grades. Results Theoretically and statistically sound models were developed, supporting the factorial validity of the scales in all groups. Multi-group longitudinal invariance was confirmed between boys and girls, overweight and normal weight students, and non-Hispanic black and white children. The construct validity of the scales was supported by hypothesized convergent and discriminant relationships within a measurement model that included correlations with physical activity (MET • min/day) measured by an accelerometer. Conclusions Scores from the scales provide valid assessments of selected beliefs and motives that are putative mediators of change in physical activity among boys and girls, as they begin the understudied transition from the fifth grade into middle school, when physical activity naturally declines. PMID:23459310

Construct validity of selected measures of physical activity beliefs and motives in fifth and sixth grade boys and girls.

PubMed

Dishman, Rod K; Saunders, Ruth P; McIver, Kerry L; Dowda, Marsha; Pate, Russell R

2013-06-01

Scales used to measure selected social-cognitive beliefs and motives for physical activity were tested among boys and girls. Covariance modeling was applied to responses obtained from large multi-ethnic samples of students in the fifth and sixth grades. Theoretically and statistically sound models were developed, supporting the factorial validity of the scales in all groups. Multi-group longitudinal invariance was confirmed between boys and girls, overweight and normal weight students, and non-Hispanic black and white children. The construct validity of the scales was supported by hypothesized convergent and discriminant relationships within a measurement model that included correlations with physical activity (MET • min/day) measured by an accelerometer. Scores from the scales provide valid assessments of selected beliefs and motives that are putative mediators of change in physical activity among boys and girls, as they begin the understudied transition from the fifth grade into middle school, when physical activity naturally declines.

Correlation of experimentally measured atomic scale properties of EUV photoresist to modeling performance: an exploration

NASA Astrophysics Data System (ADS)

Kandel, Yudhishthir; Chandonait, Jonathan; Melvin, Lawrence S.; Marokkey, Sajan; Yan, Qiliang; Grzeskowiak, Steven; Painter, Benjamin; Denbeaux, Gregory

2017-03-01

Extreme ultraviolet (EUV) lithography at 13.5 nm stands at the crossroads of next generation patterning technology for high volume manufacturing of integrated circuits. Photo resist models that form the part of overall pattern transform model for lithography play a vital role in supporting this effort. The physics and chemistry of these resists must be understood to enable the construction of accurate models for EUV Optical Proximity Correction (OPC). In this study, we explore the possibility of improving EUV photo-resist models by directly correlating the parameters obtained from experimentally measured atomic scale physical properties; namely, the effect of interaction of EUV photons with photo acid generators in standard chemically amplified EUV photoresist, and associated electron energy loss events. Atomic scale physical properties will be inferred from the measurements carried out in Electron Resist Interaction Chamber (ERIC). This study will use measured physical parameters to establish a relationship with lithographically important properties, such as line edge roughness and CD variation. The data gathered from these measurements is used to construct OPC models of the resist.

History of Physics and Conceptual Constructions: The Case of Magnetism

ERIC Educational Resources Information Center

Voutsina, Lambrini; Ravanis, Konstantinos

2011-01-01

This study documents the mental representations of magnetism constructed by students aged 15-17 and attempts to investigate whether these display the characteristics of models with an inner cohesiveness and constancy; whether they share common features with typical historical models of the Sciences; and whether they evolve through conventional…

3D-printed soft-tissue physical models of renal malignancies for individualized surgical simulation: a feasibility study.

PubMed

Maddox, Michael M; Feibus, Allison; Liu, James; Wang, Julie; Thomas, Raju; Silberstein, Jonathan L

2018-03-01

To construct patient-specific physical three-dimensional (3D) models of renal units with materials that approximates the properties of renal tissue to allow pre-operative and robotic training surgical simulation, 3D physical kidney models were created (3DSystems, Rock Hill, SC) using computerized tomography to segment structures of interest (parenchyma, vasculature, collection system, and tumor). Images were converted to a 3D surface mesh file for fabrication using a multi-jet 3D printer. A novel construction technique was employed to approximate normal renal tissue texture, printers selectively deposited photopolymer material forming the outer shell of the kidney, and subsequently, an agarose gel solution was injected into the inner cavity recreating the spongier renal parenchyma. We constructed seven models of renal units with suspected malignancies. Partial nephrectomy and renorrhaphy were performed on each of the replicas. Subsequently all patients successfully underwent robotic partial nephrectomy. Average tumor diameter was 4.4 cm, warm ischemia time was 25 min, RENAL nephrometry score was 7.4, and surgical margins were negative. A comparison was made between the seven cases and the Tulane Urology prospectively maintained robotic partial nephrectomy database. Patients with surgical models had larger tumors, higher nephrometry score, longer warm ischemic time, fewer positive surgical margins, shorter hospitalization, and fewer post-operative complications; however, the only significant finding was lower estimated blood loss (186 cc vs 236; p = 0.01). In this feasibility study, pre-operative resectable physical 3D models can be constructed and used as patient-specific surgical simulation tools; further study will need to demonstrate if this results in improvement of surgical outcomes and robotic simulation education.

Application of the transtheoretical model to sedentary behaviors and its association with physical activity status.

PubMed

Han, Ho; Pettee Gabriel, Kelley; Kohl, Harold Willis

2017-01-01

The Transtheoretical Model (TTM) is a successful framework for guiding behavior change programs for several health behaviors, yet its application to reduce of sedentary behavior has been neglected. In addition, no data exist regarding the association between determinants of sedentary behaviors based on the TTM and physical activity behavior. The purpose of this study was to investigate college students' stages of motivational readiness to avoid sedentary behaviors and relevant psychological determinants using newly developed TTM questionnaires and to identify the association between current physical activity and sedentary behaviors based on TTM constructs. Data were obtained from 225 college students enrolled in health education and physical education courses. Participants completed a package of questionnaires including validated TTM, physical activity and sitting time questionnaires. Participants also wore an accelerometer for seven consecutive days. MANOVAs were conducted to determine mean differences in psychological constructs across the TTM stages, and Chi-square tests and Spearman correlation were used to evaluate the associations between current physical activity and sedentary behavior. A majority of the participants were in the sedentary stages, and men and women differed in proportion of individuals in the stages (78.0% vs. 68.1%, respectively). The gender difference was also found in use of the processes of change. In general, the mean scores of the TTM constructs increased as the stages progressed. No significant associations were found between the TTM constructs for sedentary behavior and current physical activity levels (p>0.05). A high proportion of college students were in sedentary stages regardless of physical activity levels, but different distributions in men and women. Participants in earlier stages were less likely to utilize the TTM constructs to reduce sedentary behaviors than those in later stages. A lack of association between physical activity and the psychological determinants of sedentary behavior was found.

Pitowsky's Kolmogorovian Models and Super-determinism.

PubMed

Kellner, Jakob

2017-01-01

In an attempt to demonstrate that local hidden variables are mathematically possible, Pitowsky constructed "spin-[Formula: see text] functions" and later "Kolmogorovian models", which employs a nonstandard notion of probability. We describe Pitowsky's analysis and argue (with the benefit of hindsight) that his notion of hidden variables is in fact just super-determinism (and accordingly physically not relevant). Pitowsky's first construction uses the Continuum Hypothesis. Farah and Magidor took this as an indication that at some stage physics might give arguments for or against adopting specific new axioms of set theory. We would rather argue that it supports the opposing view, i.e., the widespread intuition "if you need a non-measurable function, it is physically irrelevant".

Social Cognitive Constructs Did Not Mediate the BEAT Cancer Intervention Effects on Objective Physical Activity Behavior Based on Multivariable Path Analysis.

PubMed

Rogers, Laura Q; Courneya, Kerry S; Anton, Phillip M; Hopkins-Price, Patricia; Verhulst, Steven; Robbs, Randall S; Vicari, Sandra K; McAuley, Edward

2017-04-01

Most breast cancer survivors do not meet physical activity recommendations. Understanding mediators of physical activity behavior change can improve interventions designed to increase physical activity in this at-risk population. Study aims were to determine the 3-month Better Exercise Adherence after Treatment for Cancer (BEAT Cancer) behavior change intervention effects on social cognitive theory constructs and the mediating role of any changes on the increase in accelerometer-measured physical activity previously reported. Post-treatment breast cancer survivors (N = 222) were randomized to BEAT Cancer or usual care. Assessments occurred at baseline, 3 months (M3), and 6 months (M6). Adjusted linear mixed model analysis of variance determined intervention effects on walking self-efficacy, outcome expectations, goal setting, and perceived barrier interference at M3. Path analysis determined mediation of intervention effects on physical activity at M6 by changes in social cognitive constructs during the intervention (i.e., baseline to M3). BEAT Cancer significantly improved self-efficacy, goals, negative outcome expectations, and barriers. Total path analysis model explained 24 % of the variance in M6 physical activity. There were significant paths from randomized intervention group to self-efficacy (β = 0.15, p < .05) and barriers (β = -0.22, p < .01). Barriers demonstrated a borderline significant association with M6 physical activity (β = -0.24, p = .05). No statistically significant indirect effects were found. Although BEAT Cancer significantly improved social cognitive constructs, no significant indirect effects on physical activity improvements 3 months post-intervention were observed (NCT00929617).

Coarse-grained, foldable, physical model of the polypeptide chain.

PubMed

Chakraborty, Promita; Zuckermann, Ronald N

2013-08-13

Although nonflexible, scaled molecular models like Pauling-Corey's and its descendants have made significant contributions in structural biology research and pedagogy, recent technical advances in 3D printing and electronics make it possible to go one step further in designing physical models of biomacromolecules: to make them conformationally dynamic. We report here the design, construction, and validation of a flexible, scaled, physical model of the polypeptide chain, which accurately reproduces the bond rotational degrees of freedom in the peptide backbone. The coarse-grained backbone model consists of repeating amide and α-carbon units, connected by mechanical bonds (corresponding to ϕ and ψ) that include realistic barriers to rotation that closely approximate those found at the molecular scale. Longer-range hydrogen-bonding interactions are also incorporated, allowing the chain to readily fold into stable secondary structures. The model is easily constructed with readily obtainable parts and promises to be a tremendous educational aid to the intuitive understanding of chain folding as the basis for macromolecular structure. Furthermore, this physical model can serve as the basis for linking tangible biomacromolecular models directly to the vast array of existing computational tools to provide an enhanced and interactive human-computer interface.

Building mental models by dissecting physical models.

PubMed

Srivastava, Anveshna

2016-01-01

When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to ensure focused learning; models that are too constrained require less supervision, but can be constructed mechanically, with little to no conceptual engagement. We propose "model-dissection" as an alternative to "model-building," whereby instructors could make efficient use of supervisory resources, while simultaneously promoting focused learning. We report empirical results from a study conducted with biology undergraduate students, where we demonstrate that asking them to "dissect" out specific conceptual structures from an already built 3D physical model leads to a significant improvement in performance than asking them to build the 3D model from simpler components. Using questionnaires to measure understanding both before and after model-based interventions for two cohorts of students, we find that both the "builders" and the "dissectors" improve in the post-test, but it is the latter group who show statistically significant improvement. These results, in addition to the intrinsic time-efficiency of "model dissection," suggest that it could be a valuable pedagogical tool. © 2015 The International Union of Biochemistry and Molecular Biology.

Mental Models in Expert Physics Reasoning.

ERIC Educational Resources Information Center

Roschelle, Jeremy; Greeno, James G.

Proposed is a relational framework for characterizing experienced physicists' representations of physics problem situations and the process of constructing these representations. A representation includes a coherent set of relations among: (1) a mental model of the objects in the situation, along with their relevant properties and relations; (2) a…

Videogame Construction by Engineering Students for Understanding Modelling Processes: The Case of Simulating Water Behaviour

ERIC Educational Resources Information Center

Pretelín-Ricárdez, Angel; Sacristán, Ana Isabel

2015-01-01

We present some results of an ongoing research project where university engineering students were asked to construct videogames involving the use of physical systems models. The objective is to help them identify and understand the elements and concepts involved in the modelling process. That is, we use game design as a constructionist approach…

Multi-Physics MRI-Based Two-Layer Fluid-Structure Interaction Anisotropic Models of Human Right and Left Ventricles with Different Patch Materials: Cardiac Function Assessment and Mechanical Stress Analysis

PubMed Central

Tang, Dalin; Yang, Chun; Geva, Tal; Gaudette, Glenn; del Nido, Pedro J.

2011-01-01

Multi-physics right and left ventricle (RV/LV) fluid-structure interaction (FSI) models were introduced to perform mechanical stress analysis and evaluate the effect of patch materials on RV function. The FSI models included three different patch materials (Dacron scaffold, treated pericardium, and contracting myocardium), two-layer construction, fiber orientation, and active anisotropic material properties. The models were constructed based on cardiac magnetic resonance (CMR) images acquired from a patient with severe RV dilatation and solved by ADINA. Our results indicate that the patch model with contracting myocardium leads to decreased stress level in the patch area, improved RV function and patch area contractility. PMID:21765559

The Social Physique Anxiety Scale: construct validity in adolescent females.

PubMed

McAuley, E; Burman, G

1993-09-01

Hart, Leary, and Rejeski have developed the Social Physique Anxiety Scale (SPA), a measure of the anxiety experienced in response to having one's physique evaluated by other people. The present study cross-validated the psychometric properties of this measure in a sample (N = 236) of adolescent competitive female gymnasts. Employing structural equation modeling, the proposed unidimensional factor structure of the SPA was supported, although some questions regarding the robustness of the fit are raised. Construct validity was demonstrated by significant inverse relationships between aspects of physical efficacy (perceived physical ability and physical self-presentation confidence) and degree of social physique anxiety. These findings are discussed in terms of possible alternative factor structures and integration of social anxiety and other psychosocial constructs to better understand physical activity behavior.

Influence of fatigue on construction workers' physical and cognitive function.

PubMed

Zhang, M; Murphy, L A; Fang, D; Caban-Martinez, A J

2015-04-01

Despite scientific evidence linking workers' fatigue to occupational safety (due to impaired physical or cognitive function), little is known about this relationship in construction workers. To assess the association between construction workers' reported fatigue and their perceived difficulties with physical and cognitive functions. Using data from a convenience sample of US construction workers participating in the 2010-11 National Health Interview Survey two multivariate weighted logistic regression models were built to predict difficulty with physical and with cognitive functions associated with workers' reported fatigue, while controlling for age, smoking status, alcohol consumption status, sleep hygiene, psychological distress and arthritis status. Of 606 construction workers surveyed, 49% reported being 'tired some days' in the past 3 months and 10% reported 'tired most days or every day'. Compared with those feeling 'never tired', workers who felt 'tired some days' were significantly more likely to report difficulty with physical function (adjusted odds ratio [AOR] = 2.03; 95% confidence interval [CI] 1.17-3.51) and cognitive function (AOR = 2.27; 95% CI 1.06-4.88) after controlling for potential confounders. Our results suggest an association between reported fatigue and experiencing difficulties with physical and cognitive functions in construction workers. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RESOLV: Readers' Representation of Reading Contexts and Tasks

ERIC Educational Resources Information Center

Rouet, Jean-François; Britt, M. Anne; Durik, Amanda M.

2017-01-01

We introduce RESOLV, a theoretical model to account for readers' construction and management of goals during text comprehension and use. RESOLV focuses on readers' experience of their physical, social, and communicative context prior to actually engaging with texts. RESOLV assumes that readers construct two types of mental models prior to reading:…

Aspects of the Cognitive Model of Physics Problem Solving.

ERIC Educational Resources Information Center

Brekke, Stewart E.

Various aspects of the cognitive model of physics problem solving are discussed in detail including relevant cues, encoding, memory, and input stimuli. The learning process involved in the recognition of familiar and non-familiar sensory stimuli is highlighted. Its four components include selection, acquisition, construction, and integration. The…

A review of the outcome expectancy construct in physical activity research.

PubMed

Williams, David M; Anderson, Eileen S; Winett, Richard A

2005-02-01

Outcome expectancy is a central construct in social cognitive models of health behavior widely used as frameworks for physical activity research. This article provides a review of the outcome expectancy construct and its application to research on physical activity. Theoretical articles describing definitions and placement of outcome expectancy within social cognitive models, as well as empirical research on outcome expectancy and physical activity, were reviewed. Self-efficacy theory, the transtheoretical model, the theory of planned behavior, and protection motivation theory differ in their labeling and conceptualization of outcome expectancy but unanimously include expected outcomes of behavior. Preliminary empirical investigation of the role of outcome expectancy in understanding physical activity has yielded mixed results. Positive outcome expectancy appears to be more predictive of physical activity in older adults than in young to middle-aged adults, and personal barriers appear to be the most predictive subtype of negative outcome expectancy. In addition, a small number of studies indicate relations between outcome expectancy and other theoretical variables, including behavioral intention, stage of change, and self-efficacy. Further research on the role of outcome expectancy is necessary to design effective physical activity interventions. New directions in outcome expectancy research could involve (a) expanding the conceptualization of outcome expectancy to include expected outcomes of sedentary behavior and affective responses to physical activity, (b) further examination of potential moderators of the relation between outcome expectancy and physical activity (such as outcome value and outcome proximity), (c) distinguishing between the role of outcome expectancy in behavior onset versus behavior maintenance, (d) examining outcome expectancy as a mechanism of change in environmental intervention approaches, and (e) further analysis of interrelations between outcome expectancy and other social cognitive variables.

Conceptualizing physical activity parenting practices using expert informed concept mapping analysis.

PubMed

Mâsse, Louise C; O'Connor, Teresia M; Tu, Andrew W; Hughes, Sheryl O; Beauchamp, Mark R; Baranowski, Tom

2017-06-14

Parents are widely recognized as playing a central role in the development of child behaviors such as physical activity. As there is little agreement as to the dimensions of physical activity-related parenting practices that should be measured or how they should be operationalized, this study engaged experts to develop an integrated conceptual framework for assessing parenting practices that influence multiple aspects of 5 to 12 year old children's participation in physical activity. The ultimate goal of this study is to inform the development of an item bank (repository of calibrated items) aimed at measuring physical activity parenting practices. Twenty four experts from 6 countries (Australia, Canada, England, Scotland, the Netherlands, & United States (US)) sorted 77 physical activity parenting practice concepts identified from our previously published synthesis of the literature (74 measures) and survey of Canadian and US parents. Concept Mapping software was used to conduct the multi-dimensional scaling (MDS) analysis and a cluster analysis of the MDS solution of the Expert's sorting which was qualitatively reviewed and commented on by the Experts. The conceptual framework includes 12 constructs which are presented using three main domains of parenting practices (neglect/control, autonomy support, and structure). The neglect/control domain includes two constructs: permissive and pressuring parenting practices. The autonomy supportive domain includes four constructs: encouragement, guided choice, involvement in child physical activities, and praises/rewards for their child's physical activity. Finally, the structure domain includes six constructs: co-participation, expectations, facilitation, modeling, monitoring, and restricting physical activity for safety or academic concerns. The concept mapping analysis provided a useful process to engage experts in re-conceptualizing physical activity parenting practices and identified key constructs to include in measures of physical activity parenting. While the constructs identified ought to be included in measures of physical activity parenting practices, it will be important to collect data among parents to further validate the content of these constructs. In conclusion, the method provided a roadmap for developing an item bank that captures key facets of physical activity parenting and ultimately serves to standardize how we operationalize measures of physical activity parenting.

Half Moon Bay, Grays Harbor, Washington: Movable-Bed Physical Model Study

DTIC Science & Technology

2006-09-01

wave machine used in Half Moon Bay physical model.................................50 Figure 28. Wave analysis output from model wave measurements...Point Chehalis used to reduce strong longshore current................82 Figure 46. Analysis of irregular waves measured at model wave Gauge 4...required several reconstruction efforts between origi- nal construction and present day due to the harsh wave climate on the Washington coast. After

Post-traumatic stress disorder and depression co-occurrence: Structural relations among disorder constructs and trait and symptom dimensions.

PubMed

Post, Loren M; Feeny, Norah C; Zoellner, Lori A; Connell, Arin M

2016-12-01

Post-traumatic stress disorder (PTSD) and major depressive disorder (MDD) in response to trauma co-occur at high rates. A better understanding of the nature of this co-occurrence is critical to developing an accurate conceptualization of the disorders. This study examined structural relations among the PTSD and MDD constructs and trait and symptom dimensions within the framework of the integrative hierarchical model of anxiety and depression. Study participants completed clinician-rated and self-report measures during a pre-treatment assessment. The sample consisted of 200 treatment-seeking individuals with a primary DSM-IV PTSD diagnosis. Structural equation modelling was used to examine the relationship between the constructs. The trait negative affect/neuroticism construct had a direct effect on both PTSD and MDD. The trait positive affect/extraversion construct had a unique, negative direct effect on MDD, and PTSD had a unique, direct effect on the physical concerns symptoms construct. An alternative model with the PTSD and MDD constructs combined into an overall general traumatic stress construct produced a decrement in model fit. These findings provide a clearer understanding of the relationship between co-occurring PTSD and MDD as disorders with shared trait negative affect/neuroticism contributing to the overlap between them and unique trait positive affect/extraversion and physical concerns differentiating them. Therefore, PTSD and MDD in response to trauma may be best represented as two distinct, yet strongly related constructs. In assessing individuals who have been exposed to trauma, practitioners should recognize that co-occurring PTSD and MDD appears to be best represented as two distinct, yet strongly related constructs. Negative affect may be the shared vulnerability directly influencing both PTSD and MDD; however, in the presence of both PTSD and MDD, low positive affect appears to be more specifically related to MDD and fear of physical sensations to PTSD, which is information that could be used by practitioners in the determination of treatment approach. Overall, these findings are clinically relevant in that they may inform assessment, treatment planning, and ultimately diagnostic classification. © 2015 The British Psychological Society.

Healthy Bodies: Construction of the Body and Health in Physical Education

ERIC Educational Resources Information Center

Webb, Louisa; Quennerstedt, Mikael; Ohman, Marie

2008-01-01

In physical education, bodies are not only moved but made. There are perceived expectations for bodies in physical education to be "healthy bodies"--for teachers to be "appropriate" physical, fit, healthy and skillful "role models" and for students to display a slim body that is equated with fitness and health. In…

Every Child a Winner with Improvised Physical Education Equipment.

ERIC Educational Resources Information Center

Irwin County Schools, Ocilla, GA.

This booklet describes physical education equipment constructed at the site of Project HOPE (Health and Optimum Physical Education) in the Irwin County School System, Ocilla, Georgia, to provide rural schools a model for elementary physical education and health services. The booklet is divided into three sections: "What To Do with No…

SIMPAVE : evaluation of virtual environments for pavement construction simulations

DOT National Transportation Integrated Search

2007-05-01

In the last couple of years, the authors have been developing virtual simulations for modeling the construction of asphalt pavements. The simulations are graphically rich, interactive, three-dimensional, with realistic physics, and allow multiple peo...

A model of scientific attitudes assessment by observation in physics learning based scientific approach: case study of dynamic fluid topic in high school

NASA Astrophysics Data System (ADS)

Yusliana Ekawati, Elvin

2017-01-01

This study aimed to produce a model of scientific attitude assessment in terms of the observations for physics learning based scientific approach (case study of dynamic fluid topic in high school). Development of instruments in this study adaptation of the Plomp model, the procedure includes the initial investigation, design, construction, testing, evaluation and revision. The test is done in Surakarta, so that the data obtained are analyzed using Aiken formula to determine the validity of the content of the instrument, Cronbach’s alpha to determine the reliability of the instrument, and construct validity using confirmatory factor analysis with LISREL 8.50 program. The results of this research were conceptual models, instruments and guidelines on scientific attitudes assessment by observation. The construct assessment instruments include components of curiosity, objectivity, suspended judgment, open-mindedness, honesty and perseverance. The construct validity of instruments has been qualified (rated load factor > 0.3). The reliability of the model is quite good with the Alpha value 0.899 (> 0.7). The test showed that the model fits the theoretical models are supported by empirical data, namely p-value 0.315 (≥ 0.05), RMSEA 0.027 (≤ 0.08)

Modeling Instruction: An Effective Model for Science Education

ERIC Educational Resources Information Center

Jackson, Jane; Dukerich, Larry; Hestenes, David

2008-01-01

The authors describe a Modeling Instruction program that places an emphasis on the construction and application of conceptual models of physical phenomena as a central aspect of learning and doing science. (Contains 1 table.)

The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease

PubMed Central

Gimeno-Santos, Elena; Raste, Yogini; Demeyer, Heleen; Louvaris, Zafeiris; de Jong, Corina; Rabinovich, Roberto A.; Hopkinson, Nicholas S.; Polkey, Michael I.; Vogiatzis, Ioannis; Tabberer, Maggie; Dobbels, Fabienne; Ivanoff, Nathalie; de Boer, Willem I.; van der Molen, Thys; Kulich, Karoly; Serra, Ignasi; Basagaña, Xavier; Troosters, Thierry; Puhan, Milo A.; Karlsson, Niklas

2015-01-01

No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD. Physical activity was assessed in a 6-week, randomised, two-way cross-over, multicentre study using PROactive draft questionnaires (daily and clinical visit versions) and two activity monitors. Item reduction followed an iterative process including classical and Rasch model analyses, and input from patients and clinical experts. 236 COPD patients from five European centres were included. Results indicated the concept of physical activity in COPD had two domains, labelled “amount” and “difficulty”. After item reduction, the daily PROactive instrument comprised nine items and the clinical visit contained 14. Both demonstrated good model fit (person separation index >0.7). Confirmatory factor analysis supported the bidimensional structure. Both instruments had good internal consistency (Cronbach's α>0.8), test–retest reliability (intraclass correlation coefficient ≥0.9) and exhibited moderate-to-high correlations (r>0.6) with related constructs and very low correlations (r<0.3) with unrelated constructs, providing evidence for construct validity. Daily and clinical visit “PROactive physical activity in COPD” instruments are hybrid tools combining a short patient-reported outcome questionnaire and two activity monitor variables which provide simple, valid and reliable measures of physical activity in COPD patients. PMID:26022965

The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease.

PubMed

Gimeno-Santos, Elena; Raste, Yogini; Demeyer, Heleen; Louvaris, Zafeiris; de Jong, Corina; Rabinovich, Roberto A; Hopkinson, Nicholas S; Polkey, Michael I; Vogiatzis, Ioannis; Tabberer, Maggie; Dobbels, Fabienne; Ivanoff, Nathalie; de Boer, Willem I; van der Molen, Thys; Kulich, Karoly; Serra, Ignasi; Basagaña, Xavier; Troosters, Thierry; Puhan, Milo A; Karlsson, Niklas; Garcia-Aymerich, Judith

2015-10-01

No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD.Physical activity was assessed in a 6-week, randomised, two-way cross-over, multicentre study using PROactive draft questionnaires (daily and clinical visit versions) and two activity monitors. Item reduction followed an iterative process including classical and Rasch model analyses, and input from patients and clinical experts.236 COPD patients from five European centres were included. Results indicated the concept of physical activity in COPD had two domains, labelled "amount" and "difficulty". After item reduction, the daily PROactive instrument comprised nine items and the clinical visit contained 14. Both demonstrated good model fit (person separation index >0.7). Confirmatory factor analysis supported the bidimensional structure. Both instruments had good internal consistency (Cronbach's α>0.8), test-retest reliability (intraclass correlation coefficient ≥0.9) and exhibited moderate-to-high correlations (r>0.6) with related constructs and very low correlations (r<0.3) with unrelated constructs, providing evidence for construct validity.Daily and clinical visit "PROactive physical activity in COPD" instruments are hybrid tools combining a short patient-reported outcome questionnaire and two activity monitor variables which provide simple, valid and reliable measures of physical activity in COPD patients. Copyright ©ERS 2015.

Engaging Students In Modeling Instruction for Introductory Physics

NASA Astrophysics Data System (ADS)

Brewe, Eric

2016-05-01

Teaching introductory physics is arguably one of the most important things that a physics department does. It is the primary way that students from other science disciplines engage with physics and it is the introduction to physics for majors. Modeling instruction is an active learning strategy for introductory physics built on the premise that science proceeds through the iterative process of model construction, development, deployment, and revision. We describe the role that participating in authentic modeling has in learning and then explore how students engage in this process in the classroom. In this presentation, we provide a theoretical background on models and modeling and describe how these theoretical elements are enacted in the introductory university physics classroom. We provide both quantitative and video data to link the development of a conceptual model to the design of the learning environment and to student outcomes. This work is supported in part by DUE #1140706.

Models, Their Application, and Scientific Anticipation: Ludwig Boltzmann's Work as Tacit Knowing

ERIC Educational Resources Information Center

Schmitt, Richard Henry

2011-01-01

Ludwig Boltzmann's work in theoretical physics exhibits an approach to the construction of theory that he transmitted to the succeeding generation by example. It involved the construction of clear models, allowed more than one, and was not based solely on the existing facts, with the intent of examining and criticizing the assumptions that made…

Investigating Students' Mental Models and Knowledge Construction of Microscopic Friction. I. Implications for Curriculum Design and Development

ERIC Educational Resources Information Center

Corpuz, Edgar D.; Rebello, N. Sanjay

2011-01-01

In this paper, we discuss the first phase of a multiphase study aimed at investigating the dynamics of students' knowledge construction in the context of unfamiliar physical phenomenon--microscopic friction. The first phase of this study involved the investigation of the variations in students' mental models of microscopic friction. Clinical…

Gaining Modelling and Mathematical Experience by Constructing Virtual Sensory Systems in Maze-Videogames

ERIC Educational Resources Information Center

Sacristán, Ana Isabel; Pretelín-Ricárdez, Angel

2017-01-01

This work is part of a research project that aims to enhance engineering students' learning of how to apply mathematics in modelling activities of real-world situations, through the construction (design and programming) of videogames. We want also for students to relate their mathematical knowledge with other disciplines (e.g., physics, computer…

Constructive methods of invariant manifolds for kinetic problems

NASA Astrophysics Data System (ADS)

Gorban, Alexander N.; Karlin, Iliya V.; Zinovyev, Andrei Yu.

2004-06-01

The concept of the slow invariant manifold is recognized as the central idea underpinning a transition from micro to macro and model reduction in kinetic theories. We present the Constructive Methods of Invariant Manifolds for model reduction in physical and chemical kinetics, developed during last two decades. The physical problem of reduced description is studied in the most general form as a problem of constructing the slow invariant manifold. The invariance conditions are formulated as the differential equation for a manifold immersed in the phase space ( the invariance equation). The equation of motion for immersed manifolds is obtained ( the film extension of the dynamics). Invariant manifolds are fixed points for this equation, and slow invariant manifolds are Lyapunov stable fixed points, thus slowness is presented as stability. A collection of methods to derive analytically and to compute numerically the slow invariant manifolds is presented. Among them, iteration methods based on incomplete linearization, relaxation method and the method of invariant grids are developed. The systematic use of thermodynamics structures and of the quasi-chemical representation allow to construct approximations which are in concordance with physical restrictions. The following examples of applications are presented: nonperturbative deviation of physically consistent hydrodynamics from the Boltzmann equation and from the reversible dynamics, for Knudsen numbers Kn∼1; construction of the moment equations for nonequilibrium media and their dynamical correction (instead of extension of list of variables) to gain more accuracy in description of highly nonequilibrium flows; determination of molecules dimension (as diameters of equivalent hard spheres) from experimental viscosity data; model reduction in chemical kinetics; derivation and numerical implementation of constitutive equations for polymeric fluids; the limits of macroscopic description for polymer molecules, etc.

Upon Generating Discrete Expanding Integrable Models of the Toda Lattice Systems and Infinite Conservation Laws

NASA Astrophysics Data System (ADS)

Zhang, Yufeng; Zhang, Xiangzhi; Wang, Yan; Liu, Jiangen

2017-01-01

With the help of R-matrix approach, we present the Toda lattice systems that have extensive applications in statistical physics and quantum physics. By constructing a new discrete integrable formula by R-matrix, the discrete expanding integrable models of the Toda lattice systems and their Lax pairs are generated, respectively. By following the constructing formula again, we obtain the corresponding (2+1)-dimensional Toda lattice systems and their Lax pairs, as well as their (2+1)-dimensional discrete expanding integrable models. Finally, some conservation laws of a (1+1)-dimensional generalised Toda lattice system and a new (2+1)-dimensional lattice system are generated, respectively.

Physical and geometrical parameters of VCBS XIII: HIP 105947

NASA Astrophysics Data System (ADS)

Gumaan Masda, Suhail; Al-Wardat, Mashhoor Ahmed; Pathan, Jiyaulla Khan Moula Khan

2018-06-01

The best physical and geometrical parameters of the main sequence close visual binary system (CVBS), HIP 105947, are presented. These parameters have been constructed conclusively using Al-Wardat’s complex method for analyzing CVBSs, which is a method for constructing a synthetic spectral energy distribution (SED) for the entire binary system using individual SEDs for each component star. The model atmospheres are in its turn built using the Kurucz (ATLAS9) line-blanketed plane-parallel models. At the same time, the orbital parameters for the system are calculated using Tokovinin’s dynamical method for constructing the best orbits of an interferometric binary system. Moreover, the mass-sum of the components, as well as the Δθ and Δρ residuals for the system, is introduced. The combination of Al-Wardat’s and Tokovinin’s methods yields the best estimations of the physical and geometrical parameters. The positions of the components in the system on the evolutionary tracks and isochrones are plotted and the formation and evolution of the system are discussed.

A new physically-based model considered antecedent rainfall for shallow landslide

NASA Astrophysics Data System (ADS)

Luo, Yu; He, Siming

2017-04-01

Rainfall is the most significant factor to cause landslide especially shallow landslide. In previous studies, rainfall intensity and duration are take part in the physically based model to determining the occurrence of the rainfall-induced landslides, but seldom considered the antecedent rainfall. In this study, antecedent rainfall is took into account to derive a new physically based model for shallow landslides prone area predicting at the basin scale. Based on the Rosso's equation of seepage flow considering the antecedent rainfall to construct the hillslope hydrology model. And then, the infinite slope stability theory is using to construct the slope stability model. At last, the model is apply in the Baisha river basin of Chengdu, Sichuan, China, and the results are compared with the one's from unconsidered antecedent rainfall. The results show that the model is simple, but has the capability of consider antecedent rainfall in the triggering mechanism of shallow landslide. Meanwhile, antecedent rainfall can make an obvious effect on shallow landslides, so in shallow landslide hazard assessment, the influence of the antecedent rainfall can't be ignored.

Extending the trans-contextual model in physical education and leisure-time contexts: examining the role of basic psychological need satisfaction.

PubMed

Barkoukis, Vassilis; Hagger, Martin S; Lambropoulos, George; Tsorbatzoudis, Haralambos

2010-12-01

The trans-contextual model (TCM) is an integrated model of motivation that aims to explain the processes by which agentic support for autonomous motivation in physical education promotes autonomous motivation and physical activity in a leisure-time context. It is proposed that perceived support for autonomous motivation in physical education is related to autonomous motivation in physical education and leisure-time contexts. Furthermore, relations between autonomous motivation and the immediate antecedents of intentions to engage in physical activity behaviour and actual behaviour are hypothesized. The purpose of the present study was to incorporate the constructs of basic psychological need satisfaction in the TCM to provide a more comprehensive explanation of motivation and demonstrate the robustness of the findings of previous tests of the model that have not incorporated these constructs. Students (N=274) from Greek secondary schools. Participants completed self-report measures of perceived autonomy support, autonomous motivation, and basic psychological need satisfaction in physical education. Follow-up measures of these variables were taken in a leisure-time context along with measures of attitudes, subjective norms, perceived behavioural control (PBC), and intentions from the theory of planned behaviour 1 week later. Self-reported physical activity behaviour was measured 4 weeks later. Results supported TCM hypotheses. Basic psychological need satisfaction variables uniquely predicted autonomous motivation in physical education and leisure time as well as the antecedents of intention, namely, attitudes, and PBC. The basic psychological need satisfaction variables also mediated the effects of perceived autonomy support on autonomous motivation in physical education. Findings support the TCM and provide further information of the mechanisms in the model and integrated theories of motivation in physical education and leisure time.

Quantitative Comparisons to Promote Inquiry in the Introductory Physics Lab

ERIC Educational Resources Information Center

Holmes, N. G.; Bonn, D. A.

2015-01-01

In a recent report, the American Association of Physics Teachers has developed an updated set of recommendations for curriculum of undergraduate physics labs. This document focuses on six major themes: constructing knowledge, modeling, designing experiments, developing technical and practical laboratory skills, analyzing and visualizing data, and…

Application of 3-Dimensional Printing Technology to Construct an Eye Model for Fundus Viewing Study

PubMed Central

Li, Xinhua; Gao, Zhishan; Yuan, Dongqing; Liu, Qinghuai

2014-01-01

Objective To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. Methods We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. Results In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. Conclusions The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research. PMID:25393277

Application of 3-dimensional printing technology to construct an eye model for fundus viewing study.

PubMed

Xie, Ping; Hu, Zizhong; Zhang, Xiaojun; Li, Xinhua; Gao, Zhishan; Yuan, Dongqing; Liu, Qinghuai

2014-01-01

To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research.

A Context-Driven Model for the Flat Roofs Construction Process through Sensing Systems, Internet-of-Things and Last Planner System

PubMed Central

Andújar-Montoya, María Dolores

2017-01-01

The main causes of building defects are errors in the design and the construction phases. These causes related to construction are mainly due to the general lack of control of construction work and represent approximately 75% of the anomalies. In particular, one of the main causes of such anomalies, which end in building defects, is the lack of control over the physical variables of the work environment during the execution of tasks. Therefore, the high percentage of defects detected in buildings that have the root cause in the construction phase could be avoidable with a more accurate and efficient control of the process. The present work proposes a novel integration model based on information and communications technologies for the automation of both construction work and its management at the execution phase, specifically focused on the flat roof construction process. Roofs represent the second area where more defects are claimed. The proposed model is based on a Web system, supported by a service oriented architecture, for the integral management of tasks through the Last Planner System methodology, but incorporating the management of task restrictions from the physical environment variables by designing specific sensing systems. Likewise, all workers are integrated into the management process by Internet-of-Things solutions that guide them throughout the execution process in a non-intrusive and transparent way. PMID:28737693

A Context-Driven Model for the Flat Roofs Construction Process through Sensing Systems, Internet-of-Things and Last Planner System.

PubMed

Andújar-Montoya, María Dolores; Marcos-Jorquera, Diego; García-Botella, Francisco Manuel; Gilart-Iglesias, Virgilio

2017-07-22

The main causes of building defects are errors in the design and the construction phases. These causes related to construction are mainly due to the general lack of control of construction work and represent approximately 75% of the anomalies. In particular, one of the main causes of such anomalies, which end in building defects, is the lack of control over the physical variables of the work environment during the execution of tasks. Therefore, the high percentage of defects detected in buildings that have the root cause in the construction phase could be avoidable with a more accurate and efficient control of the process. The present work proposes a novel integration model based on information and communications technologies for the automation of both construction work and its management at the execution phase, specifically focused on the flat roof construction process. Roofs represent the second area where more defects are claimed. The proposed model is based on a Web system, supported by a service oriented architecture, for the integral management of tasks through the Last Planner System methodology, but incorporating the management of task restrictions from the physical environment variables by designing specific sensing systems. Likewise, all workers are integrated into the management process by Internet-of-Things solutions that guide them throughout the execution process in a non-intrusive and transparent way.

Can the History of Science Contribute to Modelling in Physics Teaching?

NASA Astrophysics Data System (ADS)

Machado, Juliana; Braga, Marco Antônio Barbosa

2016-10-01

A characterization of the modelling process in science is proposed for science education, based on Mario Bunge's ideas about the construction of models in science. Galileo's Dialogues are analysed as a potentially fruitful starting point to implement strategies aimed at modelling in the classroom in the light of that proposal. It is argued that a modelling process for science education can be conceived as the evolution from phenomenological approaches towards more representational ones, emphasizing the role of abstraction and idealization in model construction. The shift of reference of theories—from sensible objects to conceptual objects—and the black-box models construction process, which are both explicitly presented features in Galileo's Dialogues, are indicated as highly relevant aspects for modelling in science education.

Maximum entropy models of ecosystem functioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertram, Jason, E-mail: jason.bertram@anu.edu.au

2014-12-05

Using organism-level traits to deduce community-level relationships is a fundamental problem in theoretical ecology. This problem parallels the physical one of using particle properties to deduce macroscopic thermodynamic laws, which was successfully achieved with the development of statistical physics. Drawing on this parallel, theoretical ecologists from Lotka onwards have attempted to construct statistical mechanistic theories of ecosystem functioning. Jaynes’ broader interpretation of statistical mechanics, which hinges on the entropy maximisation algorithm (MaxEnt), is of central importance here because the classical foundations of statistical physics do not have clear ecological analogues (e.g. phase space, dynamical invariants). However, models based on themore » information theoretic interpretation of MaxEnt are difficult to interpret ecologically. Here I give a broad discussion of statistical mechanical models of ecosystem functioning and the application of MaxEnt in these models. Emphasising the sample frequency interpretation of MaxEnt, I show that MaxEnt can be used to construct models of ecosystem functioning which are statistical mechanical in the traditional sense using a savanna plant ecology model as an example.« less

High School Students' Scientific Epistemological Beliefs, Self-Efficacy in Learning Physics and Attitudes toward Physics: A Structural Equation Model

ERIC Educational Resources Information Center

Kapucu, Serkan; Bahçivan, Eralp

2015-01-01

Background: There are some theoretical evidences that explain the relationships between core beliefs (i.e., epistemological beliefs) and peripheral beliefs (self-efficacy in learning) in the literature. The close relationships of such type of beliefs with attitudes are also discussed by some researchers. Constructing a model that investigates…

Comparing the GPR responses of real experiment and simulation of cavity

NASA Astrophysics Data System (ADS)

Yu, H.; Nam, M. J.; Kim, C.; Lee, D. K.

2017-12-01

Seoul, capital city of South Korea, has been suffering from ground subsidence mainly caused by cavities beneath the road. Urban subsidence usually brings serious social problems such as damages of human life, properties and so on. To prevent ground subsidence, Korea government embark much money in developing techniques to detect cavities in advance. Ground penetrating radar (GPR) is known as the most effective method among geophysical surveys in exploring underground cavitied but shallow ones only. For the study of GPR responses for underground cavities, real scale physical models have been made and GPR surveys are conducted. In simulating cavities with various sizes at various depths, spheres of polystyrene have been used since the electric permittivity of polystyrene has a similar value to that of the air. However, the real scale experiments only used simple shapes of cavities due to its expensive construction cost and further changing in shapes of cavities is limited once they are built. For not only comparison between field responses for the physical model and numerical responses but also for analyzing GPR responses for more various cavity shapes in numerous environments, we conducted numerical simulation of GPR responses using three-dimensional (3D) finite difference time domain (FDTD) GPR modeling algorithm employing staggered grid. We first construct numerical modeling for models similar to the physical models to confirm considering radiation pattern in numerical modeling of GPR responses which is critical to generate similar responses to field GPR data. Further, GPR responses computed for various shapes of cavities in several different environments determine not only additional construction of the physical cavities but also analyze the characteristics of GPR responses.

Basic Modeling of the Solar Atmosphere and Spectrum

NASA Technical Reports Server (NTRS)

Avrett, Eugene H.; Wagner, William J. (Technical Monitor)

2000-01-01

During the last three years we have continued the development of extensive computer programs for constructing realistic models of the solar atmosphere and for calculating detailed spectra to use in the interpretation of solar observations. This research involves two major interrelated efforts: work by Avrett and Loeser on the Pandora computer program for optically thick non-LTE modeling of the solar atmosphere including a wide range of physical processes, and work by Kurucz on the detailed high-resolution synthesis of the solar spectrum using data for over 58 million atomic and molecular lines. Our objective is to construct atmospheric models from which the calculated spectra agree as well as possible with high-and low-resolution observations over a wide wavelength range. Such modeling leads to an improved understanding of the physical processes responsible for the structure and behavior of the atmosphere.

23 CFR 635.305 - Physical construction.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Physical construction. 635.305 Section 635.305 Highways... CONSTRUCTION AND MAINTENANCE Physical Construction Authorization § 635.305 Physical construction. For purposes of this subpart the physical construction of a project is considered to consist of the actual...

23 CFR 635.305 - Physical construction.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Physical construction. 635.305 Section 635.305 Highways... CONSTRUCTION AND MAINTENANCE Physical Construction Authorization § 635.305 Physical construction. For purposes of this subpart the physical construction of a project is considered to consist of the actual...

23 CFR 635.305 - Physical construction.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Physical construction. 635.305 Section 635.305 Highways... CONSTRUCTION AND MAINTENANCE Physical Construction Authorization § 635.305 Physical construction. For purposes of this subpart the physical construction of a project is considered to consist of the actual...

23 CFR 635.305 - Physical construction.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Physical construction. 635.305 Section 635.305 Highways... CONSTRUCTION AND MAINTENANCE Physical Construction Authorization § 635.305 Physical construction. For purposes of this subpart the physical construction of a project is considered to consist of the actual...

23 CFR 635.305 - Physical construction.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Physical construction. 635.305 Section 635.305 Highways... CONSTRUCTION AND MAINTENANCE Physical Construction Authorization § 635.305 Physical construction. For purposes of this subpart the physical construction of a project is considered to consist of the actual...

The Incremental Launching Method for Educational Virtual Model

NASA Astrophysics Data System (ADS)

Martins, Octávio; Sampaio, A. Z.

This paper describes the application of virtual reality technology to the development of an educational model related to the construction of a bridge. The model allow the visualization of the physical progression of the work following a planned construction sequence, the observation of details of the form of every component of the works and carry the study of the type and method of operation of the equipment applied in the construction. The model admit interaction and then some degree of collaboration between students and teachers in the analyses of aspects concerning geometric forms, working methodology or other technical issues observed using the application. The model presents distinct advantage as educational aids in first-degree courses in Civil Engineering.

Phase space deformations in phantom cosmology

NASA Astrophysics Data System (ADS)

López, J. L.; Sabido, M.; Yee-Romero, C.

2018-03-01

We discuss the physical consequences of general phase space deformations on the minisuperspace of phantom cosmology. Based on the principle of physically equivalent descriptions in the deformed theory, we investigate for what values of the deformation parameters the arising descriptions are physically equivalent. We also construct and solve the quantum model and derive the semiclassical dynamics.

Physical consistency of subgrid-scale models for large-eddy simulation of incompressible turbulent flows

NASA Astrophysics Data System (ADS)

Silvis, Maurits H.; Remmerswaal, Ronald A.; Verstappen, Roel

2017-01-01

We study the construction of subgrid-scale models for large-eddy simulation of incompressible turbulent flows. In particular, we aim to consolidate a systematic approach of constructing subgrid-scale models, based on the idea that it is desirable that subgrid-scale models are consistent with the mathematical and physical properties of the Navier-Stokes equations and the turbulent stresses. To that end, we first discuss in detail the symmetries of the Navier-Stokes equations, and the near-wall scaling behavior, realizability and dissipation properties of the turbulent stresses. We furthermore summarize the requirements that subgrid-scale models have to satisfy in order to preserve these important mathematical and physical properties. In this fashion, a framework of model constraints arises that we apply to analyze the behavior of a number of existing subgrid-scale models that are based on the local velocity gradient. We show that these subgrid-scale models do not satisfy all the desired properties, after which we explain that this is partly due to incompatibilities between model constraints and limitations of velocity-gradient-based subgrid-scale models. However, we also reason that the current framework shows that there is room for improvement in the properties and, hence, the behavior of existing subgrid-scale models. We furthermore show how compatible model constraints can be combined to construct new subgrid-scale models that have desirable properties built into them. We provide a few examples of such new models, of which a new model of eddy viscosity type, that is based on the vortex stretching magnitude, is successfully tested in large-eddy simulations of decaying homogeneous isotropic turbulence and turbulent plane-channel flow.

Mid-Frequency Sonar Interactions With Beaked Whales

DTIC Science & Technology

2009-09-30

to acquire new high-resolution morphometric and physical-property data on beaked whales for use in the model. It is hoped that the availability of such... morphometric and physical-property data on beaked whales for use in the model. It is hoped that the availability of such a system, together with high-quality... morphometric data through computerized tomography (CT) scans on marine mammal carcasses, and constructing finite-element models of the anatomy

The Australian Computational Earth Systems Simulator

NASA Astrophysics Data System (ADS)

Mora, P.; Muhlhaus, H.; Lister, G.; Dyskin, A.; Place, D.; Appelbe, B.; Nimmervoll, N.; Abramson, D.

2001-12-01

Numerical simulation of the physics and dynamics of the entire earth system offers an outstanding opportunity for advancing earth system science and technology but represents a major challenge due to the range of scales and physical processes involved, as well as the magnitude of the software engineering effort required. However, new simulation and computer technologies are bringing this objective within reach. Under a special competitive national funding scheme to establish new Major National Research Facilities (MNRF), the Australian government together with a consortium of Universities and research institutions have funded construction of the Australian Computational Earth Systems Simulator (ACcESS). The Simulator or computational virtual earth will provide the research infrastructure to the Australian earth systems science community required for simulations of dynamical earth processes at scales ranging from microscopic to global. It will consist of thematic supercomputer infrastructure and an earth systems simulation software system. The Simulator models and software will be constructed over a five year period by a multi-disciplinary team of computational scientists, mathematicians, earth scientists, civil engineers and software engineers. The construction team will integrate numerical simulation models (3D discrete elements/lattice solid model, particle-in-cell large deformation finite-element method, stress reconstruction models, multi-scale continuum models etc) with geophysical, geological and tectonic models, through advanced software engineering and visualization technologies. When fully constructed, the Simulator aims to provide the software and hardware infrastructure needed to model solid earth phenomena including global scale dynamics and mineralisation processes, crustal scale processes including plate tectonics, mountain building, interacting fault system dynamics, and micro-scale processes that control the geological, physical and dynamic behaviour of earth systems. ACcESS represents a part of Australia's contribution to the APEC Cooperation for Earthquake Simulation (ACES) international initiative. Together with other national earth systems science initiatives including the Japanese Earth Simulator and US General Earthquake Model projects, ACcESS aims to provide a driver for scientific advancement and technological breakthroughs including: quantum leaps in understanding of earth evolution at global, crustal, regional and microscopic scales; new knowledge of the physics of crustal fault systems required to underpin the grand challenge of earthquake prediction; new understanding and predictive capabilities of geological processes such as tectonics and mineralisation.

Simulating the Rayleigh-Taylor instability with the Ising model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ball, Justin R.; Elliott, James B.

2011-08-26

The Ising model, implemented with the Metropolis algorithm and Kawasaki dynamics, makes a system with its own physics, distinct from the real world. These physics are sophisticated enough to model behavior similar to the Rayleigh-Taylor instability and by better understanding these physics, we can learn how to modify the system to better re ect reality. For example, we could add a v x and a v y to each spin and modify the exchange rules to incorporate them, possibly using two body scattering laws to construct a more realistic system.

Self-Control Constructs Related to Measures of Dietary Intake and Physical Activity in Adolescents

PubMed Central

Wills, Thomas A.; Isasi, Carmen R.; Mendoza, Don; Ainette, Michael G.

2007-01-01

Purpose To test self-regulation concepts in relation to dietary intake and physical activity patterns in adolescence, which we predicted to be influenced by components of a self-control model. Methods A survey was conducted with a multiethnic sample of 9th grade public school students in a metropolitan area (N = 539). Confirmatory analysis tested the measurement structure of self-control. Structural equation modeling tested the association of self-control constructs with measures of fruit and vegetable intake, saturated-fat intake, physical activity, and sedentary behavior. Results Confirmatory analysis of 14 indicators of self-control showed best fit for a two-factor structure, with latent constructs of good self-control (planfulness) and poor self-control (impulsiveness). Good self-control was related to more fruit and vegetable intake, more participation in sports, and less sedentary behavior. Poor self-control was related to more saturated-fat intake and less vigorous exercise. These effects were independent of gender, ethnicity, and parental education, which themselves had relations to diet and exercise measures. Multiple-group modeling indicated that effects of self-control were comparable across gender and ethnicity subgroups. Conclusions Self-control concepts are relevant for patterns of dietary intake and physical activity among adolescents. Attention to self-control processes may be warranted for prevention programs to improve health behaviors in childhood and adolescence. PMID:18023783

Sources of Variability in Physical Activity Among Inactive People with Multiple Sclerosis.

PubMed

Uszynski, Marcin K; Herring, Matthew P; Casey, Blathin; Hayes, Sara; Gallagher, Stephen; Motl, Robert W; Coote, Susan

2018-04-01

Evidence supports that physical activity (PA) improves symptoms of multiple sclerosis (MS). Although application of principles from Social Cognitive Theory (SCT) may facilitate positive changes in PA behaviour among people with multiple sclerosis (pwMS), the constructs often explain limited variance in PA. This study investigated the extent to which MS symptoms, including fatigue, depression, and walking limitations combined with the SCT constructs, explained more variance in PA than SCT constructs alone among pwMS. Baseline data, including objectively assessed PA, exercise self-efficacy, goal setting, outcome expectations, 6-min walk test, fatigue and depression, from 65 participants of the Step It Up randomized controlled trial completed in Ireland (2016), were included. Multiple regression models quantified variance explained in PA and independent associations of (1) SCT constructs, (2) symptoms and (3) SCT constructs and symptoms. Model 1 included exercise self-efficacy, exercise goal setting and multidimensional outcomes expectations for exercise and explained ~14% of the variance in PA (R 2 =0.144, p < 0.05). Model 2 included walking limitations, fatigue and depression and explained 20% of the variance in PA (R 2 =0.196, p < 0.01). Model 3 combined models 1 and 2 and explained variance increased to ~29% (R 2 =0.288; p<0.01). In Model 3, exercise self-efficacy (β=0.30, p < 0.05), walking limitations (β=0.32, p < 0.01), fatigue (β = -0.41, p < 0.01) and depression (β = 0.34, p < 0.05) were significantly and independently associated with PA. Findings suggest that relevant MS symptoms improved by PA, including fatigue, depression and walking limitations, and SCT constructs together explained more variance in PA than SCT constructs alone, providing support for targeting both SCT constructs and these symptoms in the multifactorial promotion of PA among pwMS.

Lumped parametric model of the human ear for sound transmission.

PubMed

Feng, Bin; Gan, Rong Z

2004-09-01

A lumped parametric model of the human auditoria peripherals consisting of six masses suspended with six springs and ten dashpots was proposed. This model will provide the quantitative basis for the construction of a physical model of the human middle ear. The lumped model parameters were first identified using published anatomical data, and then determined through a parameter optimization process. The transfer function of the middle ear obtained from human temporal bone experiments with laser Doppler interferometers was used for creating the target function during the optimization process. It was found that, among 14 spring and dashpot parameters, there were five parameters which had pronounced effects on the dynamic behaviors of the model. The detailed discussion on the sensitivity of those parameters was provided with appropriate applications for sound transmission in the ear. We expect that the methods for characterizing the lumped model of the human ear and the model parameters will be useful for theoretical modeling of the ear function and construction of the ear physical model.

A Conceptual Foundation for Measures of Physical Function and Behavioral Health Function for Social Security Work Disability Evaluation

PubMed Central

Marfeo, Elizabeth E.; Haley, Stephen M.; Jette, Alan M.; Eisen, Susan V.; Ni, Pengsheng; Bogusz, Kara; Meterko, Mark; McDonough, Christine M.; Chan, Leighton; Brandt, Diane E.; Rasch, Elizabeth K.

2014-01-01

Physical and mental impairments represent the two largest health condition categories for which workers receive Social Security disability benefits. Comprehensive assessment of physical and mental impairments should include aspects beyond medical conditions such as a person’s underlying capabilities as well as activity demands relevant to the context of work. The objective of this paper is to describe the initial conceptual stages of developing new measurement instruments of behavioral health and physical functioning relevant for Social Security work disability evaluation purposes. To outline a clear conceptualization of the constructs to be measured, two content models were developed using structured and informal qualitative approaches. We performed a structured literature review focusing on work disability and incorporating aspects of the International Classification of Functioning, Disability, and Health (ICF) as a unifying taxonomy for framework development. Expert interviews provided advice and consultation to enhance face validity of the resulting content models. The content model for work-related behavioral health function identifies five major domains (1) Behavior Control, (2) Basic Interactions, (3) Temperament and Personality, (4) Adaptability, and (5) Workplace Behaviors. The content model describing physical functioning includes three domains (1) Changing and Maintaining Body Position, (2) Whole Body Mobility, and (3) Carrying, Moving and Handling Objects. These content models informed subsequent measurement properties including item development, measurement scale construction, and provided conceptual coherence guiding future empirical inquiry. The proposed measurement approaches show promise to comprehensively and systematically assess physical and behavioral health functioning relevant to work. PMID:23548543

ECOHAB - HYDROGRAPHY AND BIOLOGY TO PROVIDE INFORMATION FOR THE CONSTRUCTION OF A MODEL TO PREDICT THE INITIATION, MAINTANENCE AND DISPERSAL OF RED TIDE ON THE WEST COAST OF FLORIDA

EPA Science Inventory

This program is part of a larger program called ECOHAB: Florida that includes this study as well as physical oceanography, circulation patterns, and shelf scale modeling for predicting the occurrence and transport of Karenia brevis (=Gymnodinium breve) red tides. The physical par...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabiti, Cristian; Alfonsi, Andrea; Huang, Dongli

This report collect the effort performed to improve the reliability analysis capabilities of the RAVEN code and explore new opportunity in the usage of surrogate model by extending the current RAVEN capabilities to multi physics surrogate models and construction of surrogate models for high dimensionality fields.

The influence of instructional interactions on students’ mental models about the quantization of physical observables: a modern physics course case

NASA Astrophysics Data System (ADS)

Didiş Körhasan, Nilüfer; Eryılmaz, Ali; Erkoç, Şakir

2016-01-01

Mental models are coherently organized knowledge structures used to explain phenomena. They interact with social environments and evolve with the interaction. Lacking daily experience with phenomena, the social interaction gains much more importance. In this part of our multiphase study, we investigate how instructional interactions influenced students’ mental models about the quantization of physical observables. Class observations and interviews were analysed by studying students’ mental models constructed in a modern physics course during an academic semester. The research revealed that students’ mental models were influenced by (1) the manner of teaching, including instructional methodologies and content specific techniques used by the instructor, (2) order of the topics and familiarity with concepts, and (3) peers.

Development and evaluation of social cognitive measures related to adolescent physical activity.

PubMed

Dewar, Deborah L; Lubans, David Revalds; Morgan, Philip James; Plotnikoff, Ronald C

2013-05-01

This study aimed to develop and evaluate the construct validity and reliability of modernized social cognitive measures relating to physical activity behaviors in adolescents. An instrument was developed based on constructs from Bandura's Social Cognitive Theory and included the following scales: self-efficacy, situation (perceived physical environment), social support, behavioral strategies, and outcome expectations and expectancies. The questionnaire was administered in a sample of 171 adolescents (age = 13.6 ± 1.2 years, females = 61%). Confirmatory factor analysis was employed to examine model-fit for each scale using multiple indices, including chi-square index, comparative-fit index (CFI), goodness-of-fit index (GFI), and the root mean square error of approximation (RMSEA). Reliability properties were also examined (ICC and Cronbach's alpha). Each scale represented a statistically sound measure: fit indices indicated each model to be an adequate-to-exact fit to the data; internal consistency was acceptable to good (α = 0.63-0.79); rank order repeatability was strong (ICC = 0.82-0.91). Results support the validity and reliability of social cognitive scales relating to physical activity among adolescents. As such, the developed scales have utility for the identification of potential social cognitive correlates of youth physical activity, mediators of physical activity behavior changes and the testing of theoretical models based on Social Cognitive Theory.

Modulation stability and optical soliton solutions of nonlinear Schrödinger equation with higher order dispersion and nonlinear terms and its applications

NASA Astrophysics Data System (ADS)

Arshad, Muhammad; Seadawy, Aly R.; Lu, Dianchen

2017-12-01

In optical fibers, the higher order non-linear Schrödinger equation (NLSE) with cubic quintic nonlinearity describes the propagation of extremely short pulses. We constructed bright and dark solitons, solitary wave and periodic solitary wave solutions of generalized higher order NLSE in cubic quintic non Kerr medium by applying proposed modified extended mapping method. These obtained solutions have key applications in physics and mathematics. Moreover, we have also presented the formation conditions on solitary wave parameters in which dark and bright solitons can exist for this media. We also gave graphically the movement of constructed solitary wave and soliton solutions, that helps to realize the physical phenomena's of this model. The stability of the model in normal dispersion and anomalous regime is discussed by using the modulation instability analysis, which confirms that all constructed solutions are exact and stable. Many other such types of models arising in applied sciences can also be solved by this reliable, powerful and effective method.

Construction of Hamiltonians by supervised learning of energy and entanglement spectra

NASA Astrophysics Data System (ADS)

Fujita, Hiroyuki; Nakagawa, Yuya O.; Sugiura, Sho; Oshikawa, Masaki

2018-02-01

Correlated many-body problems ubiquitously appear in various fields of physics such as condensed matter, nuclear, and statistical physics. However, due to the interplay of the large number of degrees of freedom, it is generically impossible to treat these problems from first principles. Thus the construction of a proper model, namely, effective Hamiltonian, is essential. Here, we propose a simple supervised learning algorithm for constructing Hamiltonians from given energy or entanglement spectra. We apply the proposed scheme to the Hubbard model at the half-filling, and compare the obtained effective low-energy spin model with several analytic results based on the high-order perturbation theory, which have been inconsistent with each other. We also show that our approach can be used to construct the entanglement Hamiltonian of a quantum many-body state from its entanglement spectrum as well. We exemplify this using the ground states of the S =1 /2 two-leg Heisenberg ladders. We observe a qualitative difference between the entanglement Hamiltonians of the two phases (the Haldane and the rung singlet phase) of the model due to the different origin of the entanglement. In the Haldane phase, we find that the entanglement Hamiltonian is nonlocal by nature, and the locality can be restored by introducing the anisotropy and turning the ground state into the large-D phase. Possible applications to the model construction from experimental data and to various problems of strongly correlated systems are discussed.

Beyond Performance Metrics: Examining a Decrease in Students' Physics Self-Efficacy through a Social Networks Lens

ERIC Educational Resources Information Center

Dou, Remy; Brewe, Eric; Zwolak, Justyna P.; Potvin, Geoff; Williams, Eric A.; Kramer, Laird H.

2016-01-01

The Modeling Instruction (MI) approach to introductory physics manifests significant increases in student conceptual understanding and attitudes toward physics. In light of these findings, we investigated changes in student self-efficacy while considering the construct's contribution to the career-decision making process. Students in the Fall 2014…

Intimate Partner Violence Perpetration by Court-Ordered Men: Distinctions among Subtypes of Physical Violence, Sexual Violence, Psychological Abuse, and Stalking

ERIC Educational Resources Information Center

Hall, Jeffrey E.; Walters, Mikel L.; Basile, Kathleen C.

2012-01-01

This study continues previous work documenting the structure of violence perpetrated by males against their female intimate partners. It assesses the construct validity of a measurement model depicting associations among eight subtypes of perpetration: moderate physical violence, severe physical violence, forced or coerced sexual violence, sexual…

Tracing how normative messages may influence physical activity intention

USDA-ARS?s Scientific Manuscript database

Normative messages have been shown to increase intention to do physical activity (PA). We traced how 'positive' and 'negative' normative messages influenced PA intention by comparing constructs of the model of goal-directed behaviour with descriptive norms (MGDB+DN) across control and treatment grou...

Standard solar model

NASA Technical Reports Server (NTRS)

Guenther, D. B.; Demarque, P.; Kim, Y.-C.; Pinsonneault, M. H.

1992-01-01

A set of solar models have been constructed, each based on a single modification to the physics of a reference solar model. In addition, a model combining several of the improvements has been calculated to provide a best solar model. Improvements were made to the nuclear reaction rates, the equation of state, the opacities, and the treatment of the atmosphere. The impact on both the structure and the frequencies of the low-l p-modes of the model to these improvements are discussed. It is found that the combined solar model, which is based on the best physics available (and does not contain any ad hoc assumptions), reproduces the observed oscillation spectrum (for low-l) within the errors associated with the uncertainties in the model physics (primarily opacities).

A fluctuating quantum model of the CO vibration in carboxyhemoglobin.

PubMed

Falvo, Cyril; Meier, Christoph

2011-06-07

In this paper, we present a theoretical approach to construct a fluctuating quantum model of the CO vibration in heme-CO proteins and its interaction with external laser fields. The methodology consists of mixed quantum-classical calculations for a restricted number of snapshots, which are then used to construct a parametrized quantum model. As an example, we calculate the infrared absorption spectrum of carboxy-hemoglobin, based on a simplified protein model, and found the absorption linewidth in good agreement with the experimental results. © 2011 American Institute of Physics

Integrating non-colocated well and geophysical data to capture subsurface heterogeneity at an aquifer recharge and recovery site

NASA Astrophysics Data System (ADS)

Gottschalk, Ian P.; Hermans, Thomas; Knight, Rosemary; Caers, Jef; Cameron, David A.; Regnery, Julia; McCray, John E.

2017-12-01

Geophysical data have proven to be very useful for lithological characterization. However, quantitatively integrating the information gained from acquiring geophysical data generally requires colocated lithological and geophysical data for constructing a rock-physics relationship. In this contribution, the issue of integrating noncolocated geophysical and lithological data is addressed, and the results are applied to simulate groundwater flow in a heterogeneous aquifer in the Prairie Waters Project North Campus aquifer recharge site, Colorado. Two methods of constructing a rock-physics transform between electrical resistivity tomography (ERT) data and lithology measurements are assessed. In the first approach, a maximum likelihood estimation (MLE) is used to fit a bimodal lognormal distribution to horizontal crosssections of the ERT resistivity histogram. In the second approach, a spatial bootstrap is applied to approximate the rock-physics relationship. The rock-physics transforms provide soft data for multiple point statistics (MPS) simulations. Subsurface models are used to run groundwater flow and tracer test simulations. Each model's uncalibrated, predicted breakthrough time is evaluated based on its agreement with measured subsurface travel time values from infiltration basins to selected groundwater recovery wells. We find that incorporating geophysical information into uncalibrated flow models reduces the difference with observed values, as compared to flow models without geophysical information incorporated. The integration of geophysical data also narrows the variance of predicted tracer breakthrough times substantially. Accuracy is highest and variance is lowest in breakthrough predictions generated by the MLE-based rock-physics transform. Calibrating the ensemble of geophysically constrained models would help produce a suite of realistic flow models for predictive purposes at the site. We find that the success of breakthrough predictions is highly sensitive to the definition of the rock-physics transform; it is therefore important to model this transfer function accurately.

Children's motivation in elementary physical education: an expectancy-value model of achievement choice.

PubMed

Xiang, Ping; McBride, Ron; Guan, Jianmin; Solmon, Melinda

2003-03-01

This study examined children's motivation in elementary physical education within an expectancy-value model developed by Eccles and her colleagues. Four hundred fourteen students in second and fourth grades completed questionnaires assessing their expectancy-related beliefs, subjective task values, and intention for future participation in physical education. Results indicated that expectancy-related beliefs and subjective task values were clearly distinguishable from one another across physical education and throwing. The two constructs were related to each other positively. Children's intention for future participation in physical education was positively associated with their subjective task values and/or expectancy-related beliefs. Younger children had higher motivation for learning in physical education than older children. Gender differences emerged and the findings provided empirical evidence supporting the validity of the expectancy-value model in elementary physical education.

Utility of Social Cognitive Theory in Intervention Design for Promoting Physical Activity among African-American Women: A Qualitative Study.

PubMed

Joseph, Rodney P; Ainsworth, Barbara E; Mathis, LaTanya; Hooker, Steven P; Keller, Colleen

2017-09-01

We examined the cultural relevance of Social Cognitive Theory (SCT) in the design of a physical activity intervention for African-American women. A qualitative study design was used. Twenty-five African-American women (Mean age = 38.5 years, Mean BMI = 39.4 kg·m2) were enrolled in a series of focus groups (N = 9) to elucidate how 5 SCT constructs (ie, Behavioral Capability, Outcome Expectations, Self-efficacy, Self-regulation, Social Support) can be culturally tailored in the design of a physical activity program for African-American women. For the construct of Behavioral Capability, participants were generally unaware of the amount, intensity, and types of physical activity needed for health benefits. Outcome Expectations associated with physical activity included increased energy, improved health, weight loss, and positive role modeling behaviors. Constructs of Self-efficacy and Self-regulation were elicited through the women perceiving themselves as a primary barrier to physical activity. Participants endorsed the need of a strong social support component and identified a variety of acceptable sources to include in a physical activity program (ie, family, friends, other program participants). Findings explicate the utility of SCT as a behavioral change theoretical basis for tailoring physical activity programs to African-American women.

QOL models constructed for the community-dwelling elderly with ikigai (purpose in life) as a composition factor, and the effect of habitual exercise.

PubMed

Demura, Shinichi; Kobayashi, Hidetsugu; Kitabayashi, Tamotsu

2005-09-01

The purpose of this study was to construct QOL models for the elderly that included ikigai as a composition factor and to clarify differences in two kinds of models, one constructed for the elderly with habitual exercise and the other for those without it. The subjects were 1,566 healthy community-dwelling independent people aged 60 years or more (752 males, 814 females). First, the ratio of subjects with ikigai was calculated. The ratios of subjects with different kinds of objects of ikigai were also calculated. Next, structural equation models (SEM) were constructed on the basis of social, physical, and mental QOL and ikigai. Fits of the models were evaluated. To examine whether the presence or absence of habitual exercise caused any difference in the QOL model, subjects were divided into 4 groups according to whether they were male or female and whether they had or did not have an exercise habit. Multi-population group simultaneous analysis was then performed among the four groups. More than 85% of the subjects had objects of ikigai. Ikigai is an important factor for comprehending the QOL of the elderly. It was possible to construct QOL models for the elderly with ikigai as a composition factor. The effect of physical QOL on mental QOL was negligible in females irrespective of whether they had an exercise habit. The effect of social QOL on mental QOL was profound in aged females with an exercise habit. The effect of the living situation on mental QOL was profound in aged females without an exercise habit. The effect of mental QOL on ikigai was more marked in subjects without an exercise habit than in those with an exercise habit.

Predicting physical activity and fruit and vegetable intake in adolescents: a test of the information, motivation, behavioral skills model.

PubMed

Kelly, Stephanie; Melnyk, Bernadette Mazurek; Belyea, Michael

2012-04-01

Most adolescents do not meet national recommendations regarding physical activity and/or the intake of fruits and vegetables. The purpose of this study was to explore whether variables in the information, motivation, behavioral skills (IMB) model of health promotion predicted physical activity and fruit and vegetable intake in 404 adolescents from 2 high schools in the Southwest United States using structural equation modeling (SEM). The SEM models included theoretical constructs, contextual variables, and moderators. The theoretical relationships in the IMB model were confirmed and were moderated by gender and race. Interventions that incorporate cognitive-behavioral skills building may be a key factor for promoting physical activity as well as fruit and vegetable intake in adolescents. Copyright © 2012 Wiley Periodicals, Inc.

An Amotivation Model in Physical Education

ERIC Educational Resources Information Center

Shen, Bo; Wingert, Robert K.; Li, Weidong; Sun, Haichun; Rukavina, Paul Bernard

2010-01-01

Amotivation refers to a state in which individuals cannot perceive a relationship between their behavior and that behavior's subsequent outcome. With the belief that considering amotivation as a multidimensional construct could reflect the complexity of motivational deficits in physical education, we developed this study to validate an amotivation…

Intimate Partner Violence Perpetration by Court-Ordered Men: Distinctions and Intersections among Physical Violence, Sexual Violence, Psychological Abuse, and Stalking

ERIC Educational Resources Information Center

Basile, Kathleen C.; Hall, Jeffrey E.

2011-01-01

This study assessed the construct validity of two different measurement models of male partners' perpetration of physical violence, sexual violence, psychological abuse, and stalking against intimate partners. Data were obtained from a sample of 340 men arrested for physical assault of a female spouse or partner and court ordered into batterer…

Launch Pad Physics: Accelerate Interest With Model Rocketry.

ERIC Educational Resources Information Center

Key, LeRoy F.

1982-01-01

Student activities in an interdisciplinary, model rocket science program are described, including the construction of an Ohio Scientific computer system with graphic capabilities for use in the program and cooperative efforts with the Rocket Research Institute. (JN)

Conceptual foundation for measures of physical function and behavioral health function for Social Security work disability evaluation.

PubMed

Marfeo, Elizabeth E; Haley, Stephen M; Jette, Alan M; Eisen, Susan V; Ni, Pengsheng; Bogusz, Kara; Meterko, Mark; McDonough, Christine M; Chan, Leighton; Brandt, Diane E; Rasch, Elizabeth K

2013-09-01

Physical and mental impairments represent the 2 largest health condition categories for which workers receive Social Security disability benefits. Comprehensive assessment of physical and mental impairments should include aspects beyond medical conditions such as a person's underlying capabilities as well as activity demands relevant to the context of work. The objective of this article is to describe the initial conceptual stages of developing new measurement instruments of behavioral health and physical functioning relevant for Social Security work disability evaluation purposes. To outline a clear conceptualization of the constructs to be measured, 2 content models were developed using structured and informal qualitative approaches. We performed a structured literature review focusing on work disability and incorporating aspects of the International Classification of Functioning, Disability and Health as a unifying taxonomy for framework development. Expert interviews provided advice and consultation to enhance face validity of the resulting content models. The content model for work-related behavioral health function identifies 5 major domains: (1) behavior control, (2) basic interactions, (3) temperament and personality, (4) adaptability, and (5) workplace behaviors. The content model describing physical functioning includes 3 domains: (1) changing and maintaining body position, (2) whole-body mobility, and (3) carrying, moving, and handling objects. These content models informed subsequent measurement properties including item development and measurement scale construction, and provided conceptual coherence guiding future empirical inquiry. The proposed measurement approaches show promise to comprehensively and systematically assess physical and behavioral health functioning relevant to work. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Assessment of chevron dikes for the enhancement of physical-aquatic habitat within the Middle Mississippi River, USA

NASA Astrophysics Data System (ADS)

Remo, J. W.; Pinter, N.

2012-12-01

Along the Middle Mississippi River (MMR), rehabilitation of aquatic habitat is being undertaken using river-training structures such as the blunt-nose chevron dike. Chevron dikes were initially designed to concentrate flow and thus facilitate river navigation, but this new river-training structure is now justified, in part, as a tool for creating aquatic habitat and promoting habitat heterogeneity. The ability of chevrons to create and diversify physical-aquatic habitat has not been verified. In this study, we used 2-D hydrodynamic modeling and reach-scale habitat metrics to assess changes in physical habitat and habitat heterogeneity for pre-chevron and post-chevron along a 2- km reach of the Mississippi River at St. Louis, MO. A historic reference condition (circa 1890) was also modeled to compare physical habitat in a less engineered river channel versus the new physical-habitat patches created by chevron-dike enhancement. This modeling approach quantified changes in habitat availability and diversity among selected reference conditions for a wide range of in-channel flows. Depth-velocity habitat classes were used for assessment of change in physical-habitat patches, and spatial statistical tools were employed to evaluate the reach-scale habitat patch diversity. Modeling of post-chevron channel conditions revealed increases in deep to very deep (>3.0 m) areas of slow moving (<0.6 m/s) water downstream of these structures under emergent flow conditions (≤ 1.5 x mean annual flow[MAF]) relative to pre-construction conditions. Chevron construction increased potential over-wintering habitat (deep [>3.0 m], low velocity [<0.6 m/s]) by up to 7.6 ha. The addition of the chevrons to the river channel also created some (0.8-3.8 ha) shallow-water habitat (0-1.5 m depth with a 0-0.6 m/s velocity) for flows ≤2.0 x MAF and contributed to an 8-35% increase in physical-habitat diversity compared to pre-chevron channel conditions. Comparison of the historic reference condition (less engineered channel, circa 1890) with the post-chevron channel condition, however, revealed historical conditions consisted of a physical-habitat mosaic comprised of a wider and shallower historic river channel with: very little over-wintering habitat (<0.4 ha), 45-390% more shallow-water habitat (2.4 - 11.0 ha), and 22-83% more physical-habitat diversity. Thus, while chevrons construction within the study reaches increased over-wintering habitat, shallow-water habitat, and physical-habitat diversity relative to the pre-chevron channel condition, the type of physical habitat(s) are different from what was historically found along this reach. Constructing chevrons dikes, or other dike-like structures in the river channel, can change the physical-habitat patch mosaic and likely contribute to small increases in physical-habitat heterogeneity. However, differences in the types, quantity, and diversity of physical-habitat patches created by chevron dikes in comparison to the physical-habitat patch mosaic of historic channel underscore the need for additional research to determine which physical-habitat patches are critical for the recovery of endangered or threatened aquatic organisms.

Development of a hydraulic model of the human systemic circulation

NASA Technical Reports Server (NTRS)

Sharp, M. K.; Dharmalingham, R. K.

1999-01-01

Physical and numeric models of the human circulation are constructed for a number of objectives, including studies and training in physiologic control, interpretation of clinical observations, and testing of prosthetic cardiovascular devices. For many of these purposes it is important to quantitatively validate the dynamic response of the models in terms of the input impedance (Z = oscillatory pressure/oscillatory flow). To address this need, the authors developed an improved physical model. Using a computer study, the authors first identified the configuration of lumped parameter elements in a model of the systemic circulation; the result was a good match with human aortic input impedance with a minimum number of elements. Design, construction, and testing of a hydraulic model analogous to the computer model followed. Numeric results showed that a three element model with two resistors and one compliance produced reasonable matching without undue complication. The subsequent analogous hydraulic model included adjustable resistors incorporating a sliding plate to vary the flow area through a porous material and an adjustable compliance consisting of a variable-volume air chamber. The response of the hydraulic model compared favorably with other circulation models.

Direct modeling for computational fluid dynamics

NASA Astrophysics Data System (ADS)

Xu, Kun

2015-06-01

All fluid dynamic equations are valid under their modeling scales, such as the particle mean free path and mean collision time scale of the Boltzmann equation and the hydrodynamic scale of the Navier-Stokes (NS) equations. The current computational fluid dynamics (CFD) focuses on the numerical solution of partial differential equations (PDEs), and its aim is to get the accurate solution of these governing equations. Under such a CFD practice, it is hard to develop a unified scheme that covers flow physics from kinetic to hydrodynamic scales continuously because there is no such governing equation which could make a smooth transition from the Boltzmann to the NS modeling. The study of fluid dynamics needs to go beyond the traditional numerical partial differential equations. The emerging engineering applications, such as air-vehicle design for near-space flight and flow and heat transfer in micro-devices, do require further expansion of the concept of gas dynamics to a larger domain of physical reality, rather than the traditional distinguishable governing equations. At the current stage, the non-equilibrium flow physics has not yet been well explored or clearly understood due to the lack of appropriate tools. Unfortunately, under the current numerical PDE approach, it is hard to develop such a meaningful tool due to the absence of valid PDEs. In order to construct multiscale and multiphysics simulation methods similar to the modeling process of constructing the Boltzmann or the NS governing equations, the development of a numerical algorithm should be based on the first principle of physical modeling. In this paper, instead of following the traditional numerical PDE path, we introduce direct modeling as a principle for CFD algorithm development. Since all computations are conducted in a discretized space with limited cell resolution, the flow physics to be modeled has to be done in the mesh size and time step scales. Here, the CFD is more or less a direct construction of discrete numerical evolution equations, where the mesh size and time step will play dynamic roles in the modeling process. With the variation of the ratio between mesh size and local particle mean free path, the scheme will capture flow physics from the kinetic particle transport and collision to the hydrodynamic wave propagation. Based on the direct modeling, a continuous dynamics of flow motion will be captured in the unified gas-kinetic scheme. This scheme can be faithfully used to study the unexplored non-equilibrium flow physics in the transition regime.

Discrete differential geometry: The nonplanar quadrilateral mesh

NASA Astrophysics Data System (ADS)

Twining, Carole J.; Marsland, Stephen

2012-06-01

We consider the problem of constructing a discrete differential geometry defined on nonplanar quadrilateral meshes. Physical models on discrete nonflat spaces are of inherent interest, as well as being used in applications such as computation for electromagnetism, fluid mechanics, and image analysis. However, the majority of analysis has focused on triangulated meshes. We consider two approaches: discretizing the tensor calculus, and a discrete mesh version of differential forms. While these two approaches are equivalent in the continuum, we show that this is not true in the discrete case. Nevertheless, we show that it is possible to construct mesh versions of the Levi-Civita connection (and hence the tensorial covariant derivative and the associated covariant exterior derivative), the torsion, and the curvature. We show how discrete analogs of the usual vector integral theorems are constructed in such a way that the appropriate conservation laws hold exactly on the mesh, rather than only as approximations to the continuum limit. We demonstrate the success of our method by constructing a mesh version of classical electromagnetism and discuss how our formalism could be used to deal with other physical models, such as fluids.

Construction of reduced order models for the non-linear Navier-Stokes equations using the proper orthogonal fecomposition (POD)/Galerkin method.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fike, Jeffrey A.

2013-08-01

The construction of stable reduced order models using Galerkin projection for the Euler or Navier-Stokes equations requires a suitable choice for the inner product. The standard L2 inner product is expected to produce unstable ROMs. For the non-linear Navier-Stokes equations this means the use of an energy inner product. In this report, Galerkin projection for the non-linear Navier-Stokes equations using the L2 inner product is implemented as a first step toward constructing stable ROMs for this set of physics.

Physical Model Study of Cross Vanes and Ice

DTIC Science & Technology

2009-08-01

spacing since, in the pre-scour state, experiments and the HEC - RAS hydraulic model (USACE 2002b) found that water surface ele- vation merged with the...docs/eng-manuals/em1110- 2-1612/toc.htm. USACE (2002b) HEC - RAS , Hydraulic Reference Manual. US Army Corps of Engineers Hydrologic Engineering Center...Currently little design guidance is available for constructing these structures on ice-affected rivers . This study used physical and numerical

Development and preliminary evaluation of the OsteoArthritis Questionnaire (OA-Quest): a psychometric study.

PubMed

Busija, L; Buchbinder, R; Osborne, R H

2016-08-01

This study reports the development of the OsteoArthritis Questionnaire (OA-Quest) - a new measure designed to comprehensively capture the potentially modifiable burden of osteoarthritis. Item development was guided by the a priori conceptual framework of the Personal Burden of Osteoarthritis (PBO) which captures 8 dimensions of osteoarthritis burden (Physical distress, Fatigue, Physical limitations, Psychosocial distress, Physical de-conditioning, Financial hardship, Sleep disturbances, Lost productivity). One hundred and twenty three candidate items were pretested in a clinical sample of 18 osteoarthritis patients. The measurement properties of the OA-Quest were assessed with exploratory factor analysis (EFA), Rasch modelling, and confirmatory factor analysis (CFA) in a community-based sample (n = 792). EFA replicated 7 of the 8 PBO domains. An exception was PBO Fatigue domain, with items merging into the Physical distress subscale in the OA-Quest. Following item analysis, a 42-item 7-subscale questionnaire was constructed, measuring Physical distress (seven items, Cronbach's α = 0.93), Physical limitations (11 items, α = 0.95), Psychosocial distress (seven items, α = 0.93), Physical de-conditioning (four items, α = 0.87), Financial hardship (four items, α = 0.93), Sleep disturbances (five items, α = 0.96), and Lost productivity (four items α = 0.90). A highly restricted 7-factor CFA model had excellent fit with the data (χ(2)(113) = 316.36, P < 0.001; chi-square/degrees of freedom = 2.8; comparative fit index [CFI] = 0.97; root mean square error of approximation [RMSEA] = 0.07), supporting construct validity of the new measure. The OA-Quest is a new measure of osteoarthritis burden that is founded on a comprehensive conceptual model. It has strong evidence of construct validity and provides reliable measurement across a broad range of osteoarthritis burden. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Modeling Instruction in AP Physics C: Mechanics and Electricity and Magnetism

NASA Astrophysics Data System (ADS)

Belcher, Nathan Tillman

This action research study used data from multiple assessments in Mechanics and Electricity and Magnetism to determine the viability of Modeling Instruction as a pedagogy for students in AP Physics C: Mechanics and Electricity and Magnetism. Modeling Instruction is a guided-inquiry approach to teaching science in which students progress through the Modeling Cycle to develop a fully-constructed model for a scientific concept. AP Physics C: Mechanics and Electricity and Magnetism are calculus-based physics courses, approximately equivalent to first-year calculus-based physics courses at the collegiate level. Using a one-group pretest-posttest design, students were assessed in Mechanics using the Force Concept Inventory, Mechanics Baseline Test, and 2015 AP Physics C: Mechanics Practice Exam. With the same design, students were assessed in Electricity and Magnetism on the Brief Electricity and Magnetism Assessment, Electricity and Magnetism Conceptual Assessment, and 2015 AP Physics C: Electricity and Magnetism Practice Exam. In a one-shot case study design, student scores were collected from the 2017 AP Physics C: Mechanics and Electricity and Magnetism Exams. Students performed moderately well on the assessments in Mechanics and Electricity and Magnetism, demonstrating that Modeling Instruction is a viable pedagogy in AP Physics C: Electricity and Magnetism.

A Hybrid Physics-Based Data-Driven Approach for Point-Particle Force Modeling

NASA Astrophysics Data System (ADS)

Moore, Chandler; Akiki, Georges; Balachandar, S.

2017-11-01

This study improves upon the physics-based pairwise interaction extended point-particle (PIEP) model. The PIEP model leverages a physical framework to predict fluid mediated interactions between solid particles. While the PIEP model is a powerful tool, its pairwise assumption leads to increased error in flows with high particle volume fractions. To reduce this error, a regression algorithm is used to model the differences between the current PIEP model's predictions and the results of direct numerical simulations (DNS) for an array of monodisperse solid particles subjected to various flow conditions. The resulting statistical model and the physical PIEP model are superimposed to construct a hybrid, physics-based data-driven PIEP model. It must be noted that the performance of a pure data-driven approach without the model-form provided by the physical PIEP model is substantially inferior. The hybrid model's predictive capabilities are analyzed using more DNS. In every case tested, the hybrid PIEP model's prediction are more accurate than those of physical PIEP model. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1315138 and the U.S. DOE, NNSA, ASC Program, as a Cooperative Agreement under Contract No. DE-NA0002378.

Modeling and simulation of high dimensional stochastic multiscale PDE systems at the exascale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zabaras, Nicolas J.

2016-11-08

Predictive Modeling of multiscale and Multiphysics systems requires accurate data driven characterization of the input uncertainties, and understanding of how they propagate across scales and alter the final solution. This project develops a rigorous mathematical framework and scalable uncertainty quantification algorithms to efficiently construct realistic low dimensional input models, and surrogate low complexity systems for the analysis, design, and control of physical systems represented by multiscale stochastic PDEs. The work can be applied to many areas including physical and biological processes, from climate modeling to systems biology.

Top-quark pairs at high invariant mass: a model-independent discriminator of new physics at the Large Hadron Collider.

PubMed

Barger, Vernon; Han, Tao; Walker, Devin G E

2008-01-25

We study top-quark pair production to probe new physics at the CERN Large Hadron Collider. We propose reconstruction methods for tt[over] semileptonic events and use them to reconstruct the tt[over] invariant mass. The angular distribution of top quarks in their c.m. frame can determine the spin and production subprocess for each new physics resonance. Forward-backward asymmetry and CP-odd variables can be constructed to further delineate the nature of new physics. We parametrize the new resonances with a few generic parameters and show high invariant mass top pair production may provide an early indicator for new physics beyond the standard model.

Microscopic Virtual Media (MVM) in Physics Learning: Case Study on Students Understanding of Heat Transfer

NASA Astrophysics Data System (ADS)

Wibowo, F. C.; Suhandi, A.; Rusdiana, D.; Darman, D. R.; Ruhiat, Y.; Denny, Y. R.; Suherman; Fatah, A.

2016-08-01

A Study area in physics learning is purposeful on the effects of various types of learning interventions to help students construct the basic of scientific conception about physics. Microscopic Virtual Media (MVM) are applications for physics learning to support powerful modelling microscopic involving physics concepts and processes. In this study groups (experimental) of 18±20 years old, students were studied to determine the role of MVM in the development of functional understanding of the concepts of thermal expansion in heat transfer. The experimental group used MVM in learning process. The results show that students who learned with virtual media exhibited significantly higher scores in the research tasks. Our findings proved that the MVM may be used as an alternative instructional tool, in order to help students to confront and constructed their basic of scientific conception and developed their understanding.

Physical Modeling of the Polyfrequency Filter-Compensating Device Based on the Capacitor-Coil

NASA Astrophysics Data System (ADS)

Butyrin, P. A.; Gusev, G. G.; Mikheev, D. V.; Shakirzianov, F. N.

2017-12-01

The paper presents the results of physical modeling and experimental study of the frequency characteristics of the polyfrequency filter-compensating device (PFCD) based on a capacitor-coil. The amplitude- frequency and phase-frequency characteristics of the physical PFCD model were constructed and its equivalent parameters were identified. The feasibility of a PFCD in the form of a single technical device with high technical and economic characteristics was experimentally proven. In the paper, recommendations for practical applications of the capacitor-coil-based PFCD are made and the advantages of the device over known standard passive filter-compensating devices are evaluated.

A "Model" Multivariable Calculus Course.

ERIC Educational Resources Information Center

Beckmann, Charlene E.; Schlicker, Steven J.

1999-01-01

Describes a rich, investigative approach to multivariable calculus. Introduces a project in which students construct physical models of surfaces that represent real-life applications of their choice. The models, along with student-selected datasets, serve as vehicles to study most of the concepts of the course from both continuous and discrete…

A system dynamics approach for modeling construction workers' safety attitudes and behaviors.

PubMed

Shin, Mingyu; Lee, Hyun-Soo; Park, Moonseo; Moon, Myunggi; Han, Sangwon

2014-07-01

Construction accidents are caused by an unsafe act (i.e., a person's behavior or activity that deviates from normal accepted safe procedure) and/or an unsafe condition (i.e., a hazard or an unsafe mechanical or physical environment). While there has been dramatic improvement in creating safer construction environments, relatively little is known regarding the elimination of construction workers' unsafe acts. To address this deficiency, this paper aims to develop a system dynamics (SD)-based model of construction workers' mental processes that can help analyze the feedback mechanisms and the resultant dynamics regarding the workers' safety attitudes and safe behaviors. The developed model is applied to examine the effectiveness of three safety improvement policies: incentives for safe behaviors, and increased levels of communication and immersion in accidents. Application of the model verifies the strong potential of the developed model to provide a better understanding of how to eliminate unsafe acts, and to function as a robust test-bed to assess the effectiveness of safety programs or training sessions before their implementation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Integrating Mathematical Modeling for Undergraduate Pre-Service Science Education Learning and Instruction in Middle School Classrooms

ERIC Educational Resources Information Center

Carrejo, David; Robertson, William H.

2011-01-01

Computer-based mathematical modeling in physics is a process of constructing models of concepts and the relationships between them in the scientific characteristics of work. In this manner, computer-based modeling integrates the interactions of natural phenomenon through the use of models, which provide structure for theories and a base for…

Three-Step Validation of Exercise Behavior Processes of Change in an Adolescent Sample

ERIC Educational Resources Information Center

Rhodes, Ryan E.; Berry, Tanya; Naylor, Patti-Jean; Higgins, S. Joan Wharf

2004-01-01

Though the processes of change are conceived as the core constructs of the transtheoretical model (TTM), few researchers have examined their construct validity in the physical activity domain. Further, only 1 study was designed to investigate the processes of change in an adolescent sample. The purpose of this study was to examine the exercise…

A Child Constructs an Understanding of a Water Wheel in Five Media.

ERIC Educational Resources Information Center

Forman, George

1996-01-01

Presents case study of a child trying to represent and understand the water wheel as an example of knowledge construction from the constructivism perspective. Focuses on how his understanding of physical perspective taking advances through conflicts in the use of different media (telling, drawing, paper, clay, or wood model) and how the Reggio…

From Universal Laws of Cognition to Specific Cognitive Models

ERIC Educational Resources Information Center

Chater, Nick; Brown, Gordon D. A.

2008-01-01

The remarkable successes of the physical sciences have been built on highly general quantitative laws, which serve as the basis for understanding an enormous variety of specific physical systems. How far is it possible to construct universal principles in the cognitive sciences, in terms of which specific aspects of perception, memory, or decision…

The Co-Construction of Cooperative Learning in Physical Education with Elementary Classroom Teachers

ERIC Educational Resources Information Center

Dyson, Ben P.; Colby, Rachel; Barratt, Mark

2016-01-01

The purpose of this study was to investigate generalist classroom elementary teachers' implementation of the Cooperative Learning (CL) pedagogical model into their physical education classes. The study used multiple sources of data drawing on qualitative data collection and data analysis research traditions (Miles, Huberman, & Saldana, 2014).…

Inclusion in Physical Education: From the Medical Model to Social Constructionism

ERIC Educational Resources Information Center

Grenier, Michelle

2007-01-01

The purpose of this discussion is to explore assumptions that have informed constructions of disability and to challenge these as socially constituted judgments that influence the way teachers think and act in general physical education. A secondary purpose is to introduce social constructionism as a discourse that potentially reshapes…

[Construction of individual-based ecological model for Scomber japonicas at its early growth stages in East China Sea].

PubMed

Li, Yue-Song; Chen, Xin-Jun; Yang, Hong

2012-06-01

By adopting FVCOM-simulated 3-D physical field and based on the biological processes of chub mackerel (Scomber japonicas) in its early life history from the individual-based biological model, the individual-based ecological model for S. japonicas at its early growth stages in the East China Sea was constructed through coupling the physical field in March-July with the biological model by the method of Lagrange particle tracking. The model constructed could well simulate the transport process and abundance distribution of S. japonicas eggs and larvae. The Taiwan Warm Current, Kuroshio, and Tsushima Strait Warm Current directly affected the transport process and distribution of the eggs and larvae, and indirectly affected the growth and survive of the eggs and larvae through the transport to the nursery grounds with different water temperature and foods. The spawning grounds in southern East China Sea made more contributions to the recruitment to the fishing grounds in northeast East China Sea, but less to the Yangtze estuary and Zhoushan Island. The northwestern and southwestern parts of spawning grounds had strong connectivity with the nursery grounds of Cheju and Tsushima Straits, whereas the northeastern and southeastern parts of the spawning ground had strong connectivity with the nursery grounds of Kyushu and Pacific Ocean.

Examining the individual and perceived neighborhood associations of leisure-time physical activity in persons with spinal cord injury.

PubMed

Arbour-Nicitopoulos, Kelly P; Martin Ginis, Kathleen A; Wilson, Philip M

2010-05-01

Theory of Planned Behavior (TPB) constructs have been shown to be useful for explaining leisure-time physical activity (LTPA) in persons with spinal cord injury (SCI). However, other factors not captured by the TPB may also be important predictors of LTPA for this population. The purpose of this study is to examine the role of neighborhood perceptions within the context of the TPB for understanding LTPA in persons living with SCI. This is a cross-sectional analysis (n = 574) using structural equation modeling involving measures of the TPB constructs, perceived neighborhood esthetics and sidewalks, and LTPA. TPB constructs explained 57% of the variance in intentions and 12% of the variance in behavior. Inclusion of the neighborhood variables to the model resulted in an additional 1% of the variance explained in intentions, with esthetics exhibiting significant positive relationships with the TPB variables. Integrating perceived neighborhood esthetics into the TPB framework provides additional understanding of LTPA intentions in persons living with SCI.

Subsystem functional and the missing ingredient of confinement physics in density functionals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armiento, Rickard Roberto; Mattsson, Ann Elisabet; Hao, Feng

2010-08-01

The subsystem functional scheme is a promising approach recently proposed for constructing exchange-correlation density functionals. In this scheme, the physics in each part of real materials is described by mapping to a characteristic model system. The 'confinement physics,' an essential physical ingredient that has been left out in present functionals, is studied by employing the harmonic-oscillator (HO) gas model. By performing the potential {yields} density and the density {yields} exchange energy per particle mappings based on two model systems characterizing the physics in the interior (uniform electron-gas model) and surface regions (Airy gas model) of materials for the HO gases,more » we show that the confinement physics emerges when only the lowest subband of the HO gas is occupied by electrons. We examine the approximations of the exchange energy by several state-of-the-art functionals for the HO gas, and none of them produces adequate accuracy in the confinement dominated cases. A generic functional that incorporates the description of the confinement physics is needed.« less

A new class of weight and WA systems of the Kravchenko-Kaiser functions

NASA Astrophysics Data System (ADS)

Kravchenko, V. F.; Pustovoit, V. I.; Churikov, D. V.

2014-05-01

A new class of weight and WA-systems of the Kravchenko-Kaiser functions which showed its efficiency in various physical applications is proposed and substantiated. This publication consists of three parts. In the first the Kravchenko-Kaiser weight functions are constructed on basis of the theory of atomic functions (AFs) and the Kaiser windows for the first time. In the second part new constructions of analytic WA-systems of the Kravchenko-Kaiser functions are costructed. In the third part their applications to problems of weight averaging of the difference frequency signals are considered. The numerical experiment and the physical analysis of the results for concrete physical models confirmed their efficiency. This class of functions can find wide physical applications in problems of digital signal processing, restoration of images, radar, radiometry, radio astronomy, remote sensing, etc.

Evaluation of physical activity web sites for use of behavior change theories.

PubMed

Doshi, Amol; Patrick, Kevin; Sallis, James F; Calfas, Karen

2003-01-01

Physical activity (PA) Web sites were assessed for their use of behavior change theories, including constructs of the health belief model, Transtheoretical Model, social cognitive theory, and the theory of reasoned action and planned behavior. An evaluation template for assessing PA Web sites was developed, and content validity and interrater reliability were demonstrated. Two independent raters evaluated 24 PA Web sites. Web sites varied widely in application of theory-based constructs, ranging from 5 to 48 on a 100-point scale. The most common intervention strategies were general information, social support, and realistic goal areas. Coverage of theory-based strategies was low, varying from 26% for social cognitive theory to 39% for health belief model. Overall, PA Web sites provided little assessment, feedback, or individually tailored assistance for users. They were unable to substantially tailor the on-line experience for users at different stages of change or different demographic characteristics.

A Model for Work Values and Interpersonal Relations Preferences in a School of Health-Related Professions

ERIC Educational Resources Information Center

Dietrich, Marie C.; And Others

1977-01-01

Describes a study which utilizes Holland's model of vocational choice as a construct to evaluate health related professions student personality types. Professional areas examined are occupational and physical therapy health workers and medical technologists. (LAS)

Spin-foam models and the physical scalar product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alesci, Emanuele; Centre de Physique Theorique de Luminy, Universite de la Mediterranee, F-13288 Marseille; Noui, Karim

2008-11-15

This paper aims at clarifying the link between loop quantum gravity and spin-foam models in four dimensions. Starting from the canonical framework, we construct an operator P acting on the space of cylindrical functions Cyl({gamma}), where {gamma} is the four-simplex graph, such that its matrix elements are, up to some normalization factors, the vertex amplitude of spin-foam models. The spin-foam models we are considering are the topological model, the Barrett-Crane model, and the Engle-Pereira-Rovelli model. If one of these spin-foam models provides a covariant quantization of gravity, then the associated operator P should be the so-called ''projector'' into physical statesmore » and its matrix elements should give the physical scalar product. We discuss the possibility to extend the action of P to any cylindrical functions on the space manifold.« less

Linear units improve articulation between social and physical constructs: An example from caregiver parameterization for children supported by complex medical technologies

NASA Astrophysics Data System (ADS)

Bezruczko, N.; Stanley, T.; Battle, M.; Latty, C.

2016-11-01

Despite broad sweeping pronouncements by international research organizations that social sciences are being integrated into global research programs, little attention has been directed toward obstacles blocking productive collaborations. In particular, social sciences routinely implement nonlinear, ordinal measures, which fundamentally inhibit integration with overarching scientific paradigms. The widely promoted general linear model in contemporary social science methods is largely based on untransformed scores and ratings, which are neither objective nor linear. This issue has historically separated physical and social sciences, which this report now asserts is unnecessary. In this research, nonlinear, subjective caregiver ratings of confidence to care for children supported by complex, medical technologies were transformed to an objective scale defined by logits (N=70). Transparent linear units from this transformation provided foundational insights into measurement properties of a social- humanistic caregiving construct, which clarified physical and social caregiver implications. Parameterized items and ratings were also subjected to multivariate hierarchical analysis, then decomposed to demonstrate theoretical coherence (R2 >.50), which provided further support for convergence of mathematical parameterization, physical expectations, and a social-humanistic construct. These results present substantial support for improving integration of social sciences with contemporary scientific research programs by emphasizing construction of common variables with objective, linear units.

If Only Newton Had a Rocket.

ERIC Educational Resources Information Center

Hammock, Frank M.

1988-01-01

Shows how model rocketry can be included in physics curricula. Describes rocket construction, a rocket guide sheet, calculations and launch teams. Discusses the relationships of basic mechanics with rockets. (CW)

Reading Time as Evidence for Mental Models in Understanding Physics

NASA Astrophysics Data System (ADS)

Brookes, David T.; Mestre, José; Stine-Morrow, Elizabeth A. L.

2007-11-01

We present results of a reading study that show the usefulness of probing physics students' cognitive processing by measuring reading time. According to contemporary discourse theory, when people read a text, a network of associated inferences is activated to create a mental model. If the reader encounters an idea in the text that conflicts with existing knowledge, the construction of a coherent mental model is disrupted and reading times are prolonged, as measured using a simple self-paced reading paradigm. We used this effect to study how "non-Newtonian" and "Newtonian" students create mental models of conceptual systems in physics as they read texts related to the ideas of Newton's third law, energy, and momentum. We found significant effects of prior knowledge state on patterns of reading time, suggesting that students attempt to actively integrate physics texts with their existing knowledge.

The Trans-Contextual Model of Autonomous Motivation in Education

PubMed Central

Hagger, Martin S.; Chatzisarantis, Nikos L. D.

2015-01-01

The trans-contextual model outlines the processes by which autonomous motivation toward activities in a physical education context predicts autonomous motivation toward physical activity outside of school, and beliefs about, intentions toward, and actual engagement in, out-of-school physical activity. In the present article, we clarify the fundamental propositions of the model and resolve some outstanding conceptual issues, including its generalizability across multiple educational domains, criteria for its rejection or failed replication, the role of belief-based antecedents of intentions, and the causal ordering of its constructs. We also evaluate the consistency of model relationships in previous tests of the model using path-analytic meta-analysis. The analysis supported model hypotheses but identified substantial heterogeneity in the hypothesized relationships across studies unattributed to sampling and measurement error. Based on our meta-analysis, future research needs to provide further replications of the model in diverse educational settings beyond physical education and test model hypotheses using experimental methods. PMID:27274585

The Trans-Contextual Model of Autonomous Motivation in Education: Conceptual and Empirical Issues and Meta-Analysis.

PubMed

Hagger, Martin S; Chatzisarantis, Nikos L D

2016-06-01

The trans-contextual model outlines the processes by which autonomous motivation toward activities in a physical education context predicts autonomous motivation toward physical activity outside of school, and beliefs about, intentions toward, and actual engagement in, out-of-school physical activity. In the present article, we clarify the fundamental propositions of the model and resolve some outstanding conceptual issues, including its generalizability across multiple educational domains, criteria for its rejection or failed replication, the role of belief-based antecedents of intentions, and the causal ordering of its constructs. We also evaluate the consistency of model relationships in previous tests of the model using path-analytic meta-analysis. The analysis supported model hypotheses but identified substantial heterogeneity in the hypothesized relationships across studies unattributed to sampling and measurement error. Based on our meta-analysis, future research needs to provide further replications of the model in diverse educational settings beyond physical education and test model hypotheses using experimental methods.

Unspoken Playground Rules Discourage Adolescent Physical Activity in School: A Focus Group Study of Constructs in the Prototype Willingness Model.

PubMed

Wheatley, Catherine M; Davies, Emma L; Dawes, Helen

2018-03-01

The health benefits of exercise in school are recognized, yet physical activity continues to decline during early adolescence despite numerous interventions. In this study, we investigated whether the prototype willingness model, an account of adolescent decision making that includes both reasoned behavioral choices and unplanned responses to social environments, might improve understanding of physical activity in school. We conducted focus groups with British pupils aged 12 to 13 years and used deductive thematic analysis to search for themes relating to the model. Participants described reasoned decisions about physical activity outside school and unplanned choices to be inactive during break, in response to social contexts described as more "judgmental" than in primary school. Social contexts appeared characterized by anxiety about competence, negative peer evaluation, and inactive playground norms. The prototype willingness model might more fully explain physical activity in school than reasoned behavioral models alone, indicating potential for interventions targeting anxieties about playground social environments.

Trails of meaning construction: Symbolic artifacts engage the social brain.

PubMed

Tylén, Kristian; Philipsen, Johanne Stege; Roepstorff, Andreas; Fusaroli, Riccardo

2016-07-01

Symbolic artifacts present a challenge to theories of neurocognitive processing due to their hybrid nature: they are at the same time physical objects and vehicles of intangible social meanings. While their physical properties can be read of their perceptual appearance, the meaning of symbolic artifacts depends on the perceiver's interpretative attitude and embeddedness in cultural practices. In this study, participants built models of LEGO bricks to illustrate their understanding of abstract concepts. They were then scanned with fMRI while presented to photographs of their own and others' models. When participants attended to the meaning of the models in contrast to their bare physical properties, we observed activations in mPFC and TPJ, areas often associated with social cognition, and IFG, possibly related to semantics. When contrasting own and others' models, we also found activations in precuneus, an area associated with autobiographical memory and agency, while looking at one's own collective models yielded interaction effects in rostral ACC, right IFG and left Insula. Interestingly, variability in the insula was predicted by individual differences in participants' feeling of relatedness to their fellow group members during LEGO construction activity. Our findings support a view of symbolic artifacts as neuro-cognitive trails of human social interactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Physical and numerical modeling of hydrophysical proceses on the site of underwater pipelines

NASA Astrophysics Data System (ADS)

Garmakova, M. E.; Degtyarev, V. V.; Fedorova, N. N.; Shlychkov, V. A.

2018-03-01

The paper outlines issues related to ensuring the exploitation safety of underwater pipelines that are at risk of accidents. The performed research is based on physical and mathematical modeling of local bottom erosion in the area of pipeline location. The experimental studies were performed on the basis of the Hydraulics Laboratory of the Department of Hydraulic Engineering Construction, Safety and Ecology of NSUACE (Sibstrin). In the course of physical experiments it was revealed that the intensity of the bottom soil reforming depends on the deepening of the pipeline. The ANSYS software has been used for numerical modeling. The process of erosion of the sandy bottom was modeled under the pipeline. Comparison of computational results at various mass flow rates was made.

Teaching Modeling with Partial Differential Equations: Several Successful Approaches

ERIC Educational Resources Information Center

Myers, Joseph; Trubatch, David; Winkel, Brian

2008-01-01

We discuss the introduction and teaching of partial differential equations (heat and wave equations) via modeling physical phenomena, using a new approach that encompasses constructing difference equations and implementing these in a spreadsheet, numerically solving the partial differential equations using the numerical differential equation…

REVIEWS OF TOPICAL PROBLEMS: Physics of pulsar magnetospheres

NASA Astrophysics Data System (ADS)

Beskin, Vasilii S.; Gurevich, Aleksandr V.; Istomin, Yakov N.

1986-10-01

A self-consistent model of the magnetosphere of a pulsar is constructed. This model is based on a successive solution of the equations describing global properties of the magnetosphere and on a comparison of the basic predictions of the developed theory and observational data.

A cross-lagged structural equation model of relational aggression, physical aggression, and peer status in a Chinese culture.

PubMed

Tseng, Wan-Ling; Banny, Adrienne M; Kawabata, Yoshito; Crick, Nicki R; Gau, Susan Shur-Fen

2013-01-01

This short-term longitudinal study examined the associations among relational aggression, physical aggression, and peer status (i.e., acceptance, rejection, and perceived popularity) across three time points, six months apart, in a Taiwanese sample. Participants were 198 fifth grade students (94 girls and 104 boys; Mean age = 10.35 years) from Taipei, Taiwan. Study variables were assessed using peer nomination procedure. Results from the cross-lagged structural equation models demonstrated that there were longitudinal associations between relational aggression and each of the peer status constructs while only one longitudinal association was found for physical aggression such that physical aggression positively predicted subsequent peer rejection. The longitudinal associations did not vary with gender. Results also showed high stabilities of relational aggression, physical aggression, and the three peer status constructs over 1 year as well as high concurrent association between relational and physical aggression. In addition, relational aggression and physical aggression were concurrently related to less acceptance, more rejection, and less perceived popularity, especially at the outset of the study. Findings of this study demonstrated both similarities and differences in relation to previous literature in primarily Western cultures. This study also highlights the bidirectional and complex nature of the association between aggression and peer status, which appears to depend on the form of aggression and on the particular indicator of peer status under study. Copyright © 2013 Wiley Periodicals, Inc.

[Validity evidence of the Health-Related Quality of Life for Drug Abusers Test based on the Biaxial Model of Addiction].

PubMed

Lozano, Oscar M; Rojas, Antonio J; Pérez, Cristino; González-Sáiz, Francisco; Ballesta, Rosario; Izaskun, Bilbao

2008-05-01

The aim of this work is to show evidence of the validity of the Health-Related Quality of Life for Drug Abusers Test (HRQoLDA Test). This test was developed to measure specific HRQoL for drugs abusers, within the theoretical addiction framework of the biaxial model. The sample comprised 138 patients diagnosed with opiate drug dependence. In this study, the following constructs and variables of the biaxial model were measured: severity of dependence, physical health status, psychological adjustment and substance consumption. Results indicate that the HRQoLDA Test scores are related to dependency and consumption-related problems. Multiple regression analysis reveals that HRQoL can be predicted from drug dependence, physical health status and psychological adjustment. These results contribute empirical evidence of the theoretical relationships established between HRQoL and the biaxial model, and they support the interpretation of the HRQoLDA Test to measure HRQoL in drug abusers, thus providing a test to measure this specific construct in this population.

Didactic Model--Bridging a Concept with Phenomena

ERIC Educational Resources Information Center

Shternberg, Beba; Yerushalmy, Michal

2004-01-01

The article focuses on a specific method of constructing the concept of function. The core of this method is a didactic model that plays two roles together--on the one hand a role of a model of the concept of function and on the other hand a role of a model of physical phenomena that functions can represent. This synergy of modeling situations and…

Consequences of Symmetries on the Analysis and Construction of Turbulence Models

NASA Astrophysics Data System (ADS)

Razafindralandy, Dina; Hamdouni, Aziz

2006-05-01

Since they represent fundamental physical properties in turbulence (conservation laws, wall laws, Kolmogorov energy spectrum, ...), symmetries are used to analyse common turbulence models. A class of symmetry preserving turbulence models is proposed. This class is refined such that the models respect the second law of thermodynamics. Finally, an example of model belonging to the class is numerically tested.

Combinatorial solutions to integrable hierarchies

NASA Astrophysics Data System (ADS)

Kazarian, M. E.; Lando, S. K.

2015-06-01

This paper reviews modern approaches to the construction of formal solutions to integrable hierarchies of mathematical physics whose coefficients are answers to various enumerative problems. The relationship between these approaches and the combinatorics of symmetric groups and their representations is explained. Applications of the results to the construction of efficient computations in problems related to models of quantum field theories are described. Bibliography: 34 titles.

Assessing Learning Progression of Energy Concepts across Middle School Grades: The Knowledge Integration Perspective

ERIC Educational Resources Information Center

Lee, Hee-Sun; Liu, Ou Lydia

2010-01-01

We use a construct-based assessment approach to measure learning progression of energy concepts across physical, life, and earth science contexts in middle school grades. We model the knowledge integration construct in six levels in terms of the numbers of ideas and links used in student-generated explanations. For this study, we selected 10 items…

Time on Your Hands: Modeling Time

ERIC Educational Resources Information Center

Finson, Kevin; Beaver, John

2007-01-01

Building physical models relative to a concept can be an important activity to help students develop and manipulate abstract ideas and mental models that often prove difficult to grasp. One such concept is "time". A method for helping students understand the cyclical nature of time involves the construction of a Time Zone Calculator through a…

Making Inexpensive 3-D Models

ERIC Educational Resources Information Center

Manos, Harry

2016-01-01

Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…

Collective workload organization in confined excavation of granular media

NASA Astrophysics Data System (ADS)

Monaenkova, Daria; Linevich, Vadim; Goodisman, Michael A.; Goldman, Daniel I.

2015-03-01

Many social insects collectively construct large nests in complex substrates; such structures are often composed of narrow tunnels. The benefits of collective construction, including reduced construction costs per worker come with challenges of navigation in crowded, confined spaces. Here we study the workforce organization of groups of S. invicta fire ants creating tunnels in wet granular media. We monitor the activity levels of marked (painted) workers-defined as a number of tunnel visits over 12 hours- during initiation of tunnels. The activity levels are described by a Lorenz curve with a Gini coefficient of ~ 0 . 7 indicating that a majority of the excavation is performed by a minority of workers. We hypothesize that this workload distribution is beneficial for excavation in crowded conditions, and use a 2D cellular automata (CA) model to reproduce behaviors of the excavating ants. CA simulations reveal that tunnel construction rates decrease in groups of equally active animals compared to groups with the natural workload distribution. We use predictions of the CA model to organize collective excavation of granular material by teams of digging robots, and use the robots to test hypotheses of crowded excavation in the physical world. We acknowledge support of National Science Foundation, Physics of Living Systems division.

Psychosocial sources of stress and burnout in the construction sector: a structural equation model.

PubMed

Meliá, Josep L; Becerril, Marta

2007-11-01

This study develops and tests a structural equation model of social stress factors in the construction industry. Leadership behaviours, role conflict and mobbing behaviours are considered exogenous sources of stress; the experience of tension and burnout are considered mediator variables; and psychological well-being, propensity to quit and perceived quality are the final dependent variables. A sample of Spanish construction workers participated voluntarily and anonymously in the study. After considering the indices of modification, leadership showed direct effects on the propensity to quit and perceived quality. The overall fit of the model is adequate (chi2 (13)= 10.69, p = .637, GFI= .975, AGFI= .93, RMR= .230, NFI= .969, TLI= 1.016, CFI= 1.000, RMSEA= .329). Construction has been considered a sector characterized more by high physical risks than socially-related risks. In this context, these findings about the effects of social sources of stress in construction raise new questions about the organizational characteristics of the sector and their psychosocial risks.

Uncertainty analysis of signal deconvolution using a measured instrument response function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartouni, E. P.; Beeman, B.; Caggiano, J. A.

2016-10-05

A common analysis procedure minimizes the ln-likelihood that a set of experimental observables matches a parameterized model of the observation. The model includes a description of the underlying physical process as well as the instrument response function (IRF). Here, we investigate the National Ignition Facility (NIF) neutron time-of-flight (nTOF) spectrometers, the IRF is constructed from measurements and models. IRF measurements have a finite precision that can make significant contributions to the uncertainty estimate of the physical model’s parameters. Finally, we apply a Bayesian analysis to properly account for IRF uncertainties in calculating the ln-likelihood function used to find the optimummore » physical parameters.« less

Developing a Psychometric Instrument to Measure Physical Education Teachers' Job Demands and Resources

ERIC Educational Resources Information Center

Zhang, Tan; Chen, Ang

2017-01-01

Based on the job demands-resources model, the study developed and validated an instrument that measures physical education teachers' job demands-resources perception. Expert review established content validity with the average item rating of 3.6/5.0. Construct validity and reliability were determined with a teacher sample (n = 397). Exploratory…

Patterns of Response Times and Response Choices to Science Questions: The Influence of Relative Processing Time

ERIC Educational Resources Information Center

Heckler, Andrew F.; Scaife, Thomas M.

2015-01-01

We report on five experiments investigating response choices and response times to simple science questions that evoke student "misconceptions," and we construct a simple model to explain the patterns of response choices. Physics students were asked to compare a physical quantity represented by the slope, such as speed, on simple physics…

Gender Differences in College Leisure Time Physical Activity: Application of the Theory of Planned Behavior and Integrated Behavioral Model

ERIC Educational Resources Information Center

Beville, Jill M.; Umstattd Meyer, M. Renée; Usdan, Stuart L.; Turner, Lori W.; Jackson, John C.; Lian, Brad E.

2014-01-01

Objective: National data consistently report that males participate in leisure time physical activity (LTPA) at higher rates than females. This study expanded previous research to examine gender differences in LTPA of college students using the theory of planned behavior (TPB) by including 2 additional constructs, descriptive norm and…

Final report: Constructing comprehensive models of grain boundaries using high-throughput experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demkowicz, Michael; Schuh, Christopher; Marzouk, Youssef

2016-08-29

This is the final report on project DE-SC0008926. The goal of this project was to create capabilities for constructing, analyzing, and modeling experimental databases of the crystallographic characters and physical properties of thousands of individual grain boundaries (GBs) in polycrystalline metals. This project focused on gallium permeation through aluminum (Al) GBs and hydrogen uptake into nickel (Ni) GBs as model problems. This report summarizes the work done within the duration of this project (including the original three-year award and the subsequent one-year renewal), i.e. from August 1, 2012 until April 30, 2016.

Mathematical modeling of a process the rolling delivery

NASA Astrophysics Data System (ADS)

Stepanov, Mikhail A.; Korolev, Andrey A.

2018-03-01

An adduced analysis of the scientific researches in a domain of the rolling equipments, also research of properties the working material. A one of perspective direction of scientific research this is mathematical modeling. That is broadly used in many scientific disciplines and especially at the technical, applied sciences. With the aid of mathematical modeling it can be study of physical properties of the researching objects and systems. A research of the rolling delivery and transporting devices realized with the aid of a construction of mathematical model of appropriate process. To be described the basic principles and conditions of a construction of mathematical models of the real objects. For example to be consider a construction of mathematical model the rolling delivery device. For a construction that is model used system of the equations, which consist of: Lagrange’s equation of a motion, describing of the law conservation of energy of a mechanical system, and the Navier - Stokes equations, which characterize of the flow of a continuous non-compressed fluid. A construction of mathematical model the rolling deliver to let determined of a total energy of device, and therefore to got the dependence upon the power of drive to a gap between of rolls. A corroborate the hypothesis about laminar the flow of a material into the rolling gap of deliver.

Basalt fiber manufacturing technology and the possibility of its use in dentistry

NASA Astrophysics Data System (ADS)

Karavaeva, E.; Rogozhnikov, A.; Nikitin, V.; Cherepennikov, Yu; Lysakov, A.

2015-11-01

The article touches upon the technology of basalt fiber manufacturing and prospects of its use in dental practice. Two kinds of construction using basalt fiber have been proposed. The first one is a splinting construction for mobile teeth and the second one is the reinforced base for removable plate-denture. The work presents the results of the investigation of physical and mechanical properties of the constructions based on basalt fiber. It also describes the aspects of biomechanical modeling of such constructions in the ANSYS software package. The results of the investigation have proved that applying constructions using basalt fiber is highly promising for prosthetic dentistry practice.

The reservoir model: a differential equation model of psychological regulation.

PubMed

Deboeck, Pascal R; Bergeman, C S

2013-06-01

Differential equation models can be used to describe the relationships between the current state of a system of constructs (e.g., stress) and how those constructs are changing (e.g., based on variable-like experiences). The following article describes a differential equation model based on the concept of a reservoir. With a physical reservoir, such as one for water, the level of the liquid in the reservoir at any time depends on the contributions to the reservoir (inputs) and the amount of liquid removed from the reservoir (outputs). This reservoir model might be useful for constructs such as stress, where events might "add up" over time (e.g., life stressors, inputs), but individuals simultaneously take action to "blow off steam" (e.g., engage coping resources, outputs). The reservoir model can provide descriptive statistics of the inputs that contribute to the "height" (level) of a construct and a parameter that describes a person's ability to dissipate the construct. After discussing the model, we describe a method of fitting the model as a structural equation model using latent differential equation modeling and latent distribution modeling. A simulation study is presented to examine recovery of the input distribution and output parameter. The model is then applied to the daily self-reports of negative affect and stress from a sample of older adults from the Notre Dame Longitudinal Study on Aging. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

The Reservoir Model: A Differential Equation Model of Psychological Regulation

PubMed Central

Deboeck, Pascal R.; Bergeman, C. S.

2017-01-01

Differential equation models can be used to describe the relationships between the current state of a system of constructs (e.g., stress) and how those constructs are changing (e.g., based on variable-like experiences). The following article describes a differential equation model based on the concept of a reservoir. With a physical reservoir, such as one for water, the level of the liquid in the reservoir at any time depends on the contributions to the reservoir (inputs) and the amount of liquid removed from the reservoir (outputs). This reservoir model might be useful for constructs such as stress, where events might “add up” over time (e.g., life stressors, inputs), but individuals simultaneously take action to “blow off steam” (e.g., engage coping resources, outputs). The reservoir model can provide descriptive statistics of the inputs that contribute to the “height” (level) of a construct and a parameter that describes a person's ability to dissipate the construct. After discussing the model, we describe a method of fitting the model as a structural equation model using latent differential equation modeling and latent distribution modeling. A simulation study is presented to examine recovery of the input distribution and output parameter. The model is then applied to the daily self-reports of negative affect and stress from a sample of older adults from the Notre Dame Longitudinal Study on Aging. PMID:23527605

Psychosocial constructs were not mediators of intervention effects for dietary and physical activity outcomes in a church-based lifestyle intervention: Delta Body and Soul III.

PubMed

Thomson, Jessica L; Tussing-Humphreys, Lisa M; Zoellner, Jamie M; Goodman, Melissa H

2016-08-01

Evaluating an intervention's theoretical basis can inform design modifications to produce more effective interventions. Hence the present study's purpose was to determine if effects from a multicomponent lifestyle intervention were mediated by changes in the psychosocial constructs decisional balance, self-efficacy and social support. Delta Body and Soul III, conducted from August 2011 to May 2012, was a 6-month, church-based, lifestyle intervention designed to improve diet quality and increase physical activity. Primary outcomes, diet quality and aerobic and strength/flexibility physical activity, as well as psychosocial constructs, were assessed via self-report, interviewer-administered surveys at baseline and post intervention. Mediation analyses were conducted using ordinary least squares (continuous outcomes) and maximum likelihood logistic (dichotomous outcomes) regression path analysis. Churches (five intervention and three control) were recruited from four counties in the Lower Mississippi Delta region of the USA. Rural, Southern, primarily African-American adults (n 321). Based upon results from the multiple mediation models, there was no evidence that treatment (intervention v. control) indirectly influenced changes in diet quality or physical activity through its effects on decisional balance, self-efficacy and social support. However, there was evidence for direct effects of social support for exercise on physical activity and of self-efficacy for sugar-sweetened beverages on diet quality. Results do not support the hypothesis that the psychosocial constructs decisional balance, self-efficacy and social support were the theoretical mechanisms by which the Delta Body and Soul III intervention influenced changes in diet quality and physical activity.

Teacher Learning of Technology Enhanced Formative Assessment

NASA Astrophysics Data System (ADS)

Feldman, Allan; Capobianco, Brenda M.

2008-02-01

This study examined the integration of technology enhanced formative assessment (FA) into teachers' practice. Participants were high school physics teachers interested in improving their use of a classroom response system (CRS) to promote FA. Data were collected using interviews, direct classroom observations, and collaborative discussions. The physics teachers engaged in collaborative action research (AR) to learn how to use FA and CRS to promote student and teacher learning. Data were analyzed using open coding, cross-case analysis, and content analysis. Results from data analysis allowed researchers to construct a model for knowledge skills necessary for the integration of technology enhanced FA into teachers' practice. The model is as a set of four technologies: hardware and software; methods for constructing FA items; pedagogical methods; and curriculum integration. The model is grounded in the idea that teachers must develop these respective technologies as they interact with the CRS (i.e., hardware and software, item construction) and their existing practice (i.e., pedagogical methods, curriculum). Implications are that for teachers to make FA an integral part of their practice using CRS, they must: 1) engage in the four technologies; 2) understand the nature of FA; and 3) collaborate with other interested teachers through AR.

Quantitative Diagnosis of Continuous-Valued, Stead-State Systems

NASA Technical Reports Server (NTRS)

Rouquette, N.

1995-01-01

Quantitative diagnosis involves numerically estimating the values of unobservable parameters that best explain the observed parameter values. We consider quantitative diagnosis for continuous, lumped- parameter, steady-state physical systems because such models are easy to construct and the diagnosis problem is considerably simpler than that for corresponding dynamic models. To further tackle the difficulties of numerically inverting a simulation model to compute a diagnosis, we propose to decompose a physical system model in terms of feedback loops. This decomposition reduces the dimension of the problem and consequently decreases the diagnosis search space. We illustrate this approach on a model of thermal control system studied in earlier research.

Experimental Control of Simple Pendulum Model

ERIC Educational Resources Information Center

Medina, C.

2004-01-01

This paper conveys information about a Physics laboratory experiment for students with some theoretical knowledge about oscillatory motion. Students construct a simple pendulum that behaves as an ideal one, and analyze model assumption incidence on its period. The following aspects are quantitatively analyzed: vanishing friction, small amplitude,…

How-to-Do-It: Countercurrent Heat Exchange in Vertebrate Limbs.

ERIC Educational Resources Information Center

Franklin, George B.; Plakke, Ronald K.

1988-01-01

Describes principals of physics that are manifested in simple biological systems of heat conservation structures. Outlines materials needed, data collection, analysis, and discussion questions for construction and operation of two models, one that is a countercurrent heat exchange model and one that is not. (RT)

ADM Analysis of gravity models within the framework of bimetric variational formalism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golovnev, Alexey; Karčiauskas, Mindaugas; Nyrhinen, Hannu J., E-mail: agolovnev@yandex.ru, E-mail: mindaugas.karciauskas@helsinki.fi, E-mail: hannu.nyrhinen@helsinki.fi

2015-05-01

Bimetric variational formalism was recently employed to construct novel bimetric gravity models. In these models an affine connection is generated by an additional tensor field which is independent of the physical metric. In this work we demonstrate how the ADM decomposition can be applied to study such models and provide some technical intermediate details. Using ADM decomposition we are able to prove that a linear model is unstable as has previously been indicated by perturbative analysis. Moreover, we show that it is also very difficult if not impossible to construct a non-linear model which is ghost-free within the framework ofmore » bimetric variational formalism. However, we demonstrate that viable models are possible along similar lines of thought. To this end, we consider a set up in which the affine connection is a variation of the Levi-Civita one. As a proof of principle we construct a gravity model with a massless scalar field obtained this way.« less

Patients' mental models and adherence to outpatient physical therapy home exercise programs.

PubMed

Rizzo, Jon

2015-05-01

Within physical therapy, patient adherence usually relates to attending appointments, following advice, and/or undertaking prescribed exercise. Similar to findings for general medical adherence, patient adherence to physical therapy home exercise programs (HEP) is estimated between 35 and 72%. Adherence to HEPs is a multifactorial and poorly understood phenomenon, with no consensus regarding a common theoretical framework that best guides empirical or clinical efforts. Mental models, a construct used to explain behavior and decision-making in the social sciences, may serve as this framework. Mental models comprise an individual's tacit thoughts about how the world works. They include assumptions about new experiences and expectations for the future based on implicit comparisons between current and past experiences. Mental models play an important role in decision-making and guiding actions. This professional theoretical article discusses empirical research demonstrating relationships among mental models, prior experience, and adherence decisions in medical and physical therapy contexts. Specific issues related to mental models and physical therapy patient adherence are discussed, including the importance of articulation of patients' mental models, assessment of patients' mental models that relate to exercise program adherence, discrepancy between patient and provider mental models, and revision of patients' mental models in ways that enhance adherence. The article concludes with practical implications for physical therapists and recommendations for further research to better understand the role of mental models in physical therapy patient adherence behavior.

Knee joint laxity does not moderate the relationship between quadriceps strength and physical function in knee osteoarthritis patients: A cross-sectional study.

PubMed

Altubasi, Ibrahim M

2018-06-07

Knee osteoarthritis is a common and a disabling musculoskeletal disorder. Patients with knee osteoarthritis have activity limitations which are linked to the strength of the quadriceps muscle. Previous research reported that the relationship between quadriceps muscle strength and physical function is moderated by the level of knee joint frontal plane laxity. The purpose of the current study is to reexamine the moderation effect of the knee joint laxity as measured by stress radiographs on the relationship between quadriceps muscle strength and physical function. One-hundred and sixty osteoarthritis patients participated in this cross-sectional study. Isometric quadriceps muscle strength was measured using an isokinetic dynamometer. Self-rated and performance-based physical function were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale and Get Up and Go test, respectively. Stress radiographs which were taken while applying varus and valgus loads to knee using the TELOS device. Knee joint laxity was determined by measuring the distance between joint surfaces on the medial and lateral sides. Hierarchical multiple regression models were constructed to study the moderation effect of laxity on the strength function relationship. Two regression models were constructed for self-rated and performance-based function. After controlling for demographics, strength contributed significantly in the models. The addition of laxity and laxity-strength interaction did not add significant contributions in the regression models. Frontal plane knee joint laxity measured by stress radiographs does not moderate the relationship between quadriceps muscle strength and physical function in patients with osteoarthritis. Copyright © 2018 Elsevier B.V. All rights reserved.

Healthcare information technology's relativity problems: a typology of how patients' physical reality, clinicians' mental models, and healthcare information technology differ.

PubMed

Smith, Sean W; Koppel, Ross

2014-01-01

To model inconsistencies or distortions among three realities: patients' physical reality; clinicians' mental models of patients' conditions, laboratories, etc; representation of that reality in electronic health records (EHR). To serve as a potential tool for quality improvement of EHRs. Using observations, literature, information technology (IT) logs, vendor and US Food and Drug Administration reports, we constructed scenarios/models of how patients' realities, clinicians' mental models, and EHRs can misalign to produce distortions in comprehension and treatment. We then categorized them according to an emergent typology derived from the cases themselves and refined the categories based on insights gained from the literature of interactive sociotechnical systems analysis, decision support science, and human computer interaction. Typical of grounded theory methods, the categories underwent repeated modifications. We constructed 45 scenarios of misalignment between patients' physical realities, clinicians' mental models, and EHRs. We then identified five general types of misrepresentation in these cases: IT data too narrowly focused; IT data too broadly focused; EHRs miss critical reality; data multiplicities-perhaps contradictory or confusing; distortions from data reflected back and forth across users, sensors, and others. The 45 scenarios are presented, organized by the five types. With humans, there is a physical reality and actors' mental models of that reality. In healthcare, there is another player: the EHR/healthcare IT, which implicitly and explicitly reflects many mental models, facets of reality, and measures thereof that vary in reliability and consistency. EHRs are both microcosms and shapers of medical care. Our typology and scenarios are intended to be useful to healthcare IT designers and implementers in improving EHR systems and reducing the unintended negative consequences of their use.

On Mechanical Transitions in Biologically Motivated Soft Matter Systems

NASA Astrophysics Data System (ADS)

Fogle, Craig

The notion of phase transitions as a characterization of a change in physical properties pervades modern physics. Such abrupt and fundamental changes in the behavior of physical systems are evident in condensed matter system and also occur in nuclear and subatomic settings. While this concept is less prevalent in the field of biology, recent advances have pointed to its relevance in a number of settings. Recent studies have modeled both the cell cycle and cancer as phase transition in physical systems. In this dissertation we construct simplified models for two biological systems. As described by those models, both systems exhibit phase transitions. The first model is inspired by the shape transition in the nuclei of neutrophils during differentiation. During differentiation the nucleus transitions from spherical to a shape often described as "beads on a string." As a simplified model of this system, we investigate the spherical-to-wrinkled transition in an elastic core bounded to a fluid shell system. We find that this model exhibits a first-order phase transition, and the shape that minimizes the energy of the system scales as (micror3/kappa). . The second system studied is motivated by the dynamics of globular proteins. These proteins may undergoes conformational changes with large displacements relative to their size. Transitions between conformational states are not possible if the dynamics are governed strictly by linear elasticity. We construct a model consisting of an predominantly elastic region near the energetic minimum of the system and a non-linear softening of the system at a critical displacement. We find that this simple model displays very rich dynamics include a sharp dynamical phase transition and driving-force-dependent symmetry breaking.

Using Lab Notebooks to Examine Students' Engagement in Modeling in an Upper-Division Electronics Lab Course

ERIC Educational Resources Information Center

Stanley, Jacob T.; Su, Weifeng; Lewandowski, H. J.

2017-01-01

We demonstrate how students' use of modeling can be examined and assessed using student notebooks collected from an upper-division electronics lab course. The use of models is a ubiquitous practice in undergraduate physics education, but the process of constructing, testing, and refining these models is much less common. We focus our attention on…

Polyhedron Modeling of Rubble-Pile Asteroids

NASA Technical Reports Server (NTRS)

Korycansky, D. G.; Asphaug, E.

2005-01-01

We report on progress in modeling of asteroids as collections of rigid polyhedra ("rubble piles"). Such models are (idealized) candidates for asteroid structures: aggregates of irregular rocky subunits that are held together by self-gravity and friction. We have taken several steps toward greater realism and physical interest in construction of the models (although the gravitational fields are being treated in a simplified manner). -

Animal population dynamics: Identification of critical components

USGS Publications Warehouse

Emlen, J.M.; Pikitch, E.K.

1989-01-01

There is a growing interest in the use of population dynamics models in environmental risk assessment and the promulgation of environmental regulatory policies. Unfortunately, because of species and areal differences in the physical and biotic influences on population dynamics, such models must almost inevitably be both complex and species- or site-specific. Given the emormous variety of species and sites of potential concern, this fact presents a problem; it simply is not possible to construct models for all species and circumstances. Therefore, it is useful, before building predictive population models, to discover what input parameters are of critical importance to the desired output. This information should enable the construction of simpler and more generalizable models. As a first step, it is useful to consider population models as composed to two, partly separable classes, one comprising the purely mechanical descriptors of dynamics from given demographic parameter values, and the other describing the modulation of the demographic parameters by environmental factors (changes in physical environment, species interactions, pathogens, xenobiotic chemicals). This division permits sensitivity analyses to be run on the first of these classes, providing guidance for subsequent model simplification. We here apply such a sensitivity analysis to network models of mammalian and avian population dynamics.

Models accounting for intention-behavior discordance in the physical activity domain: a user's guide, content overview, and review of current evidence.

PubMed

Rhodes, Ryan E; Yao, Christopher A

2015-02-07

There is a growing concern among researchers with the limited effectiveness and yet subsequent stagnation of theories applied to physical activity (PA). One of the most highlighted areas of concern is the established gap between intention and PA, yet the considerable use of models that assume intention is the proximal antecedent of PA. The objective of this review was to: 1) provide a guide and thematic analysis of the available models that include constructs that address intention-behavior discordance and 2) highlight the evidence for these structures in the PA domain. A literature search was conducted among 13 major databases to locate relevant models and PA studies published before August 2014. Sixteen models were identified and nine overall themes for post-intentional constructs were created. Of the 16 models, eight were applied to 36 PA studies. Early evidence supported maintenance self-efficacy, behavioral regulation strategies, affective judgments, perceived control/opportunity, habit, and extraversion as reliable predictors of post-intention PA. Several intention-behavior discordance models exist within the literature, but are not used frequently. Further efforts are needed to test these models, preferably with experimental designs.

Improved treatment of optics in the Lindquist-Wheeler models

NASA Astrophysics Data System (ADS)

Clifton, Timothy; Ferreira, Pedro G.; O'Donnell, Kane

2012-01-01

We consider the optical properties of Lindquist-Wheeler (LW) models of the Universe. These models consist of lattices constructed from regularly arranged discrete masses. They are akin to the Wigner-Seitz construction of solid state physics, and result in a dynamical description of the large-scale Universe in which the global expansion is given by a Friedmann-like equation. We show that if these models are constructed in a particular way then the redshifts of distant objects, as well as the dynamics of the global space-time, can be made to be in good agreement with the homogeneous and isotropic Friedmann-Lemaître-Robertson-Walker (FLRW) solutions of Einstein’s equations, at the level of ≲3% out to z≃2. Angular diameter and luminosity distances, on the other hand, differ from those found in the corresponding FLRW models, while being consistent with the “empty beam” approximation, together with the shearing effects due to the nearest masses. This can be compared with the large deviations found from the corresponding FLRW values obtained in a previous study that considered LW models constructed in a different way. We therefore advocate the improved LW models we consider here as useful constructions that appear to faithfully reproduce both the dynamical and observational properties of space-times containing discrete masses.

Measurement of Pressure Responses in a Physical Model of a Human Head with High Shape Fidelity Based on Ct/mri Data

NASA Astrophysics Data System (ADS)

Miyazaki, Yusuke; Tachiya, Hiroshi; Anata, Kenji; Hojo, Akihiro

This study discusses a head injury mechanism in case of a human head subjected to impact, from results of impact experiments by using a physical model of a human head with high-shape fidelity. The physical model was constructed by using rapid prototyping technology from the three-dimensional CAD data, which obtained from CT/MRI images of a subject's head. As results of the experiments, positive pressure responses occurred at the impacted site, whereas negative pressure responses occurred at opposite the impacted site. Moreover, the absolute maximum value of pressure occurring at the frontal region of the intracranial space of the head model resulted in same or higher than that at the occipital site in each case that the impact force was imposed on frontal or occipital region. This result has not been showed in other study using simple shape physical models. And, the result corresponds with clinical evidences that brain contusion mainly occurs at the frontal part in each impact direction. Thus, physical model with accurate skull shape is needed to clarify the mechanism of brain contusion.

An accurate computational method for an order parameter with a Markov state model constructed using a manifold-learning technique

NASA Astrophysics Data System (ADS)

Ito, Reika; Yoshidome, Takashi

2018-01-01

Markov state models (MSMs) are a powerful approach for analyzing the long-time behaviors of protein motion using molecular dynamics simulation data. However, their quantitative performance with respect to the physical quantities is poor. We believe that this poor performance is caused by the failure to appropriately classify protein conformations into states when constructing MSMs. Herein, we show that the quantitative performance of an order parameter is improved when a manifold-learning technique is employed for the classification in the MSM. The MSM construction using the K-center method, which has been previously used for classification, has a poor quantitative performance.

The effect of mathematical model development on the instruction of acceleration to introductory physics students

NASA Astrophysics Data System (ADS)

Sauer, Tim Allen

The purpose of this study was to evaluate the effectiveness of utilizing student constructed theoretical math models when teaching acceleration to high school introductory physics students. The goal of the study was for the students to be able to utilize mathematical modeling strategies to improve their problem solving skills, as well as their standardized scientific and conceptual understanding. This study was based on mathematical modeling research, conceptual change research and constructivist theory of learning, all of which suggest that mathematical modeling is an effective way to influence students' conceptual connectiveness and sense making of formulaic equations and problem solving. A total of 48 students in two sections of high school introductory physics classes received constructivist, inquiry-based, cooperative learning, and conceptual change-oriented instruction. The difference in the instruction for the 24 students in the mathematical modeling treatment group was that they constructed every formula they needed to solve problems from data they collected. In contrast, the instructional design for the control group of 24 students allowed the same instruction with assigned problems solved with formulas given to them without explanation. The results indicated that the mathematical modeling students were able to solve less familiar and more complicated problems with greater confidence and mental flexibility than the control group students. The mathematical modeling group maintained fewer alternative conceptions consistently in the interviews than did the control group. The implications for acceleration instruction from these results were discussed.

Chaos Theory as a Model for Life Transitions Counseling: Nonlinear Dynamics and Life's Changes

ERIC Educational Resources Information Center

Bussolari, Cori J.; Goodell, Judith A.

2009-01-01

Chaos theory is presented for counselors working with clients experiencing life transitions. It is proposed as a model that considers disorder, unpredictability, and lack of control as normal parts of transition processes. Nonlinear constructs from physics are adapted for use in counseling. The model provides a method clients can use to…

Dataflow models for fault-tolerant control systems

NASA Technical Reports Server (NTRS)

Papadopoulos, G. M.

1984-01-01

Dataflow concepts are used to generate a unified hardware/software model of redundant physical systems which are prone to faults. Basic results in input congruence and synchronization are shown to reduce to a simple model of data exchanges between processing sites. Procedures are given for the construction of congruence schemata, the distinguishing features of any correctly designed redundant system.

Constructive Models of Discrete and Continuous Physical Phenomena

DTIC Science & Technology

2014-02-08

BOURKE , T., CAILLAUD, B., AND POUZET, M. The fundamentals of hybrid systems modelers. Journal of Computer and System Sciences 78, 3 (2012), 877–910...8. BENVENISTE, A., BOURKE , T., CAILLAUD, B., AND POUZET, M. Index theory for hy- brid DAE systems (abstract and slides). In Synchronous Programming

SUSCEPTIBILITY OF A GULF OF MEXICO ESTUARY TO HYPOXIA: AN ANALYSIS USING BOX MODELS

EPA Science Inventory

The extent of hypoxia and the physical factors affecting development and maintenance of hypoxia were examined for Pensacola Bay, Florida (USA) by conducting monthly water quality surveys for 3 years and by constructing salt-and-water balance box models using the resulting data. W...

Utilizing Rapid Prototyping for Architectural Modeling

ERIC Educational Resources Information Center

Kirton, E. F.; Lavoie, S. D.

2006-01-01

This paper will discuss our approach to, success with and future direction in rapid prototyping for architectural modeling. The premise that this emerging technology has broad and exciting applications in the building design and construction industry will be supported by visual and physical evidence. This evidence will be presented in the form of…

The Influence of the Enhanced Vector Meson Sector on the Properties of the Matter of Neutron Stars

PubMed Central

Bednarek, Ilona; Manka, Ryszard; Pienkos, Monika

2014-01-01

This paper gives an overview of the model of a neutron star with non-zero strangeness constructed within the framework of the nonlinear realization of the chiral symmetry. The emphasis is put on the physical properties of the matter of a neutron star as well as on its internal structure. The obtained solution is particularly aimed at the problem of the construction of a theoretical model of a neutron star matter with hyperons that will give high value of the maximum mass. PMID:25188304

Ensemble inequivalence and Maxwell construction in the self-gravitating ring model

NASA Astrophysics Data System (ADS)

Rocha Filho, T. M.; Silvestre, C. H.; Amato, M. A.

2018-06-01

The statement that Gibbs equilibrium ensembles are equivalent is a base line in many approaches in the context of equilibrium statistical mechanics. However, as a known fact, for some physical systems this equivalence may not be true. In this paper we illustrate from first principles the inequivalence between the canonical and microcanonical ensembles for a system with long range interactions. We make use of molecular dynamics simulations and Monte Carlo simulations to explore the thermodynamics properties of the self-gravitating ring model and discuss on what conditions the Maxwell construction is applicable.

Robotic suturing on the FLS model possesses construct validity, is less physically demanding, and is favored by more surgeons compared with laparoscopy.

PubMed

Stefanidis, Dimitrios; Hope, William W; Scott, Daniel J

2011-07-01

The value of robotic assistance for intracorporeal suturing is not well defined. We compared robotic suturing with laparoscopic suturing on the FLS model with a large cohort of surgeons. Attendees (n=117) at the SAGES 2006 Learning Center robotic station placed intracorporeal sutures on the FLS box-trainer model using conventional laparoscopic instruments and the da Vinci® robot. Participant performance was recorded using a validated objective scoring system, and a questionnaire regarding demographics, task workload, and suturing modality preference was completed. Construct validity for both tasks was assessed by comparing the performance scores of subjects with various levels of experience. A validated questionnaire was used for workload measurement. Of the participants, 84% had prior laparoscopic and 10% prior robotic suturing experience. Within the allotted time, 83% of participants completed the suturing task laparoscopically and 72% with the robot. Construct validity was demonstrated for both simulated tasks according to the participants' advanced laparoscopic experience, laparoscopic suturing experience, and self-reported laparoscopic suturing ability (p<0.001 for all) and according to prior robotic experience, robotic suturing experience, and self-reported robotic suturing ability (p<0.001 for all), respectively. While participants achieved higher suturing scores with standard laparoscopy compared with the robot (84±75 vs. 56±63, respectively; p<0.001), they found the laparoscopic task more physically demanding (NASA score 13±5 vs. 10±5, respectively; p<0.001) and favored the robot as their method of choice for intracorporeal suturing (62 vs. 38%, respectively; p<0.01). Construct validity was demonstrated for robotic suturing on the FLS model. Suturing scores were higher using standard laparoscopy likely as a result of the participants' greater experience with laparoscopic suturing versus robotic suturing. Robotic assistance decreases the physical demand of intracorporeal suturing compared with conventional laparoscopy and, in this study, was the preferred suturing method by most surgeons. Curricula for robotic suturing training need to be developed.

A physics based method for combining multiple anatomy models with application to medical simulation.

PubMed

Zhu, Yanong; Magee, Derek; Ratnalingam, Rishya; Kessel, David

2009-01-01

We present a physics based approach to the construction of anatomy models by combining components from different sources; different image modalities, protocols, and patients. Given an initial anatomy, a mass-spring model is generated which mimics the physical properties of the solid anatomy components. This helps maintain valid spatial relationships between the components, as well as the validity of their shapes. Combination can be either replacing/modifying an existing component, or inserting a new component. The external forces that deform the model components to fit the new shape are estimated from Gradient Vector Flow and Distance Transform maps. We demonstrate the applicability and validity of the described approach in the area of medical simulation, by showing the processes of non-rigid surface alignment, component replacement, and component insertion.

The Effect of New Vocabulary on Problem Solving in Novice Physics Students.

ERIC Educational Resources Information Center

Sobolewski, Stanley J.

One of the difficulties encountered by novice problem solvers in introductory physics is in the area of problem solving. It has been shown in other studies that poor problem solvers are affected by the surface aspects of the problem in contrast with more efficient problem solvers who are capable of constructing a mental model of the physical…

Promoting Physical Activity in Hong Kong Chinese Young People: Factors Influencing Their Subjective Task Values and Expectancy Beliefs in Physical Activity

ERIC Educational Resources Information Center

Pang, Bonnie

2014-01-01

According to Eccles et al.'s (1983) Expectancy Value Model, the two major constructs that influence young people's activity choice are subjective task value and expectancy beliefs (Eccles et al., 1983). Eccles et al. (1983) conceptually distinguished four dimensions of subjective task value: attainment value, intrinsic value, utility value and…

Diagnosis by integrating model-based reasoning with knowledge-based reasoning

NASA Technical Reports Server (NTRS)

Bylander, Tom

1988-01-01

Our research investigates how observations can be categorized by integrating a qualitative physical model with experiential knowledge. Our domain is diagnosis of pathologic gait in humans, in which the observations are the gait motions, muscle activity during gait, and physical exam data, and the diagnostic hypotheses are the potential muscle weaknesses, muscle mistimings, and joint restrictions. Patients with underlying neurological disorders typically have several malfunctions. Among the problems that need to be faced are: the ambiguity of the observations, the ambiguity of the qualitative physical model, correspondence of the observations and hypotheses to the qualitative physical model, the inherent uncertainty of experiential knowledge, and the combinatorics involved in forming composite hypotheses. Our system divides the work so that the knowledge-based reasoning suggests which hypotheses appear more likely than others, the qualitative physical model is used to determine which hypotheses explain which observations, and another process combines these functionalities to construct a composite hypothesis based on explanatory power and plausibility. We speculate that the reasoning architecture of our system is generally applicable to complex domains in which a less-than-perfect physical model and less-than-perfect experiential knowledge need to be combined to perform diagnosis.

A matrix for the qualitative evaluation of nursing tasks.

PubMed

Durosaiye, Isaiah O; Hadjri, Karim; Liyanage, Champika L; Bennett, Kina

2018-04-01

To formulate a model for patient-nurse interaction; to compile a comprehensive list of nursing tasks on hospital wards; and to construct a nursing tasks demand matrix. The physical demands associated with nursing profession are of growing interest among researchers. Yet, it is the complexity of nursing tasks that defines the demands of ward nurses' role. This study explores nursing tasks, based on patient-nurse interaction on hospital wards. Extant literature was reviewed to formulate a patient-nurse interaction model. Twenty ward nurses were interviewed to compile a list of nursing tasks. These nursing tasks were mapped against the patient-nurse interaction model. A patient-nurse interaction model was created, consisting of: (1) patient care, (2) patient surveillance and (3) patient support. Twenty-three nursing tasks were identified. The nursing tasks demand matrix was constructed. Ward managers may use a nursing tasks demand matrix to determine the demands of nursing tasks on ward nurses. While many studies have explored either the physical or the psychosocial aspects of nursing tasks separately, this study suggests that the physicality of nursing tasks must be evaluated in tandem with their complexity. Ward managers may take a holistic approach to nursing tasks evaluation by using a nursing tasks demand matrix. © 2017 John Wiley & Sons Ltd.

Servicescape: physical environment of hospital pharmacies and hospital pharmacists' work outcomes.

PubMed

Lin, Blossom Yen-Ju; Leu, Wen-Jye; Breen, Gerald-Mark; Lin, Wen-Hung

2008-01-01

In health care, architects, interior designers, engineers, and health care administrators need to pay attention to the construction and design of health care facilities. Research is needed to better understand how health professionals and employees perceive their work environment to improve the physical environment in which they work. The purpose of this study was to test the effect of the physical environment of hospital pharmacies on hospital pharmacists' work outcomes. This cross-sectional mailed survey study of individual hospital pharmacists used a structured questionnaire developed to cover perceptions of the ambient conditions and the space/function(s) of pharmacists' work environments. It included aspects such as dispensing areas, pharmaceuticals areas, storage areas, and administrative offices. Work outcomes were job satisfaction, intentions to leave or reduce job working hours, and job-related stress. Hospital pharmacists in Taiwan (n = 182) returned the mailed surveys. Structural equation modeling was performed to validate the construct of the physical environment of a hospital pharmacy and the causal model for testing the effect of the physical environment on pharmacists' work outcomes. For hospital pharmacy workplaces, more favorable perceptions of the workplace's physical environment were positively associated with overall job satisfaction, but such perceptions were also negatively related to intentions to quit employment or to reduce working hours. However, the effect of the physical environment on job stress within the workplace was not supported. The designs of physical environments deserve attention to create more appropriate and healthier environments for hospital pharmacies. Further research should be devoted to trace more psychological responses to the physical environment from a longitudinal perspective.

Mechanisms explaining Coulomb's electric force & Lorentz's magnetic force from a classical perspective

NASA Astrophysics Data System (ADS)

Correnti, Dan S.

2018-06-01

The underlying mechanisms of the fundamental electric and magnetic forces are not clear in current models; they are mainly mathematical constructs. This study examines the underlying physics from a classical viewpoint to explain Coulomb's electric force and Lorentz's magnetic force. This is accomplished by building upon already established physics. Although no new physics is introduced, extension of existing models is made by close examination. We all know that an electron carries a bound cylindrical B-field (CBF) as it translates. Here, we show how the electron CBF plays an intrinsic role in the generation of the electric and magnetic forces.

The NASA-AMES Research Center Stratospheric Aerosol Model. 1. Physical Processes and Computational Analogs

NASA Technical Reports Server (NTRS)

Turco, R. P.; Hamill, P.; Toon, O. B.; Whitten, R. C.; Kiang, C. S.

1979-01-01

A time-dependent one-dimensional model of the stratospheric sulfate aerosol layer is presented. In constructing the model, a wide range of basic physical and chemical processes are incorporated in order to avoid predetermining or biasing the model predictions. The simulation, which extends from the surface to an altitude of 58 km, includes the troposphere as a source of gases and condensation nuclei and as a sink for aerosol droplets. The size distribution of aerosol particles is resolved into 25 categories with particle radii increasing geometrically from 0.01 to 2.56 microns such that particle volume doubles between categories.

Active chainmail fabrics for soft robotic applications

NASA Astrophysics Data System (ADS)

Ransley, Mark; Smitham, Peter; Miodownik, Mark

2017-08-01

This paper introduces a novel type of smart textile with electronically responsive flexibility. The chainmail inspired fabric is modelled parametrically and simulated via a rigid body physics framework with an embedded model of temperature controlled actuation. Our model assumes that individual fabric linkages are rigid and deform only through their own actuation, thereby decoupling flexibility from stiffness. A physical prototype of the active fabric is constructed and it is shown that flexibility can be significantly controlled through actuator strains of ≤10%. Applications of these materials to soft-robotics such as dynamically reconfigurable orthoses and splints are discussed.

The Dutch-Flemish PROMIS Physical Function item bank exhibited strong psychometric properties in patients with chronic pain.

PubMed

Crins, Martine H P; Terwee, Caroline B; Klausch, Thomas; Smits, Niels; de Vet, Henrica C W; Westhovens, Rene; Cella, David; Cook, Karon F; Revicki, Dennis A; van Leeuwen, Jaap; Boers, Maarten; Dekker, Joost; Roorda, Leo D

2017-07-01

The objective of this study was to assess the psychometric properties of the Dutch-Flemish Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank in Dutch patients with chronic pain. A bank of 121 items was administered to 1,247 Dutch patients with chronic pain. Unidimensionality was assessed by fitting a one-factor confirmatory factor analysis and evaluating resulting fit statistics. Items were calibrated with the graded response model and its fit was evaluated. Cross-cultural validity was assessed by testing items for differential item functioning (DIF) based on language (Dutch vs. English). Construct validity was evaluated by calculation correlations between scores on the Dutch-Flemish PROMIS Physical Function measure and scores on generic and disease-specific measures. Results supported the Dutch-Flemish PROMIS Physical Function item bank's unidimensionality (Comparative Fit Index = 0.976, Tucker Lewis Index = 0.976) and model fit. Item thresholds targeted a wide range of physical function construct (threshold-parameters range: -4.2 to 5.6). Cross-cultural validity was good as four items only showed DIF for language and their impact on item scores was minimal. Physical Function scores were strongly associated with scores on all other measures (all correlations ≤ -0.60 as expected). The Dutch-Flemish PROMIS Physical Function item bank exhibited good psychometric properties. Development of a computer adaptive test based on the large bank is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Hadronic Octaves: Symphony in Treble Clef

NASA Astrophysics Data System (ADS)

Ne'eman, Yuval

2002-06-01

Pythagoreanism, as derived from the physics of music, an artificial quantized system, involved simple ratios between integers and was conjectured by the Pythagoreans to extend to the whole of physics (the Music of the Spheres). It hit the jackpot in 1895 with Balmer's formula and has dominated XXth Century physics, with its Quantum Foundations. I review the history of Hadron Spectroscopy and my personal role in 1958-1964, i.e. (1) my 1960 discovery of SU(3) symmetry with an octet assignment for the j = 1/2 baryons (independently reached somewhat later by M. Gell-Mann), and (2) in 1961 (with H. Goldberg) my mathematical construction of a structural model which was then developed into the physical quark model by Gell-Mann and Zweig.

The physical map of wheat chromosome 1BS provides insights into its gene space organization and evolution

PubMed Central

2013-01-01

Background The wheat genome sequence is an essential tool for advanced genomic research and improvements. The generation of a high-quality wheat genome sequence is challenging due to its complex 17 Gb polyploid genome. To overcome these difficulties, sequencing through the construction of BAC-based physical maps of individual chromosomes is employed by the wheat genomics community. Here, we present the construction of the first comprehensive physical map of chromosome 1BS, and illustrate its unique gene space organization and evolution. Results Fingerprinted BAC clones were assembled into 57 long scaffolds, anchored and ordered with 2,438 markers, covering 83% of chromosome 1BS. The BAC-based chromosome 1BS physical map and gene order of the orthologous regions of model grass species were consistent, providing strong support for the reliability of the chromosome 1BS assembly. The gene space for chromosome 1BS spans the entire length of the chromosome arm, with 76% of the genes organized in small gene islands, accompanied by a two-fold increase in gene density from the centromere to the telomere. Conclusions This study provides new evidence on common and chromosome-specific features in the organization and evolution of the wheat genome, including a non-uniform distribution of gene density along the centromere-telomere axis, abundance of non-syntenic genes, the degree of colinearity with other grass genomes and a non-uniform size expansion along the centromere-telomere axis compared with other model cereal genomes. The high-quality physical map constructed in this study provides a solid basis for the assembly of a reference sequence of chromosome 1BS and for breeding applications. PMID:24359668

Construct Validity of the Societal Outreach Scale (SOS).

PubMed

Fike, David S; Denton, Jason; Walk, Matt; Kish, Jennifer; Gorman, Ira

2018-04-01

The American Physical Therapy Association (APTA) has been working toward a vision of increasing professional focus on societal-level health. However, performance of social responsibility and related behaviors by physical therapists remain relatively poorly integrated into practice. Promoting a focus on societal outreach is necessary for all health care professionals to impact the health of their communities. The objective was to document the validity of the 14-item Societal Outreach Scale (SOS) for use with practicing physical therapists. This study used a cross-sectional survey. The SOS was transmitted via email to all therapists who were licensed and practicing in 10 states in the United States that were purposefully selected to assure a broad representation. A sample of 2612 usable responses was received. Factor analysis was applied to assess construct validity of the instrument. Of alternate models, a 3-factor model best demonstrated goodness of fit with the sample data according to conventional indices (standardized root mean squared residual = .03, comparative fit index .96, root mean square error of approximation = .06). The 3 factors measured by the SOS were labeled Societal-Level Health Advocacy, Community Engagement/Social Integration, and Political Engagement. Internal consistency reliability was 0.7 for all factors. The 3-factor SOS demonstrated acceptable validity and reliability. Though the sample included a broad representation of physical therapists, this was a single cross-sectional study. Additional confirmatory factor analysis, reliability testing, and word refinement of the tool are warranted. Given the construct validity and reliability of the 3-factor SOS, it is recommended for use as a validated instrument to measure physical therapists' performance of social responsibility and related behaviors.

Can the History of Science Contribute to Modelling in Physics Teaching? The Case of Galilean Studies and Mario Bunge's Epistemology

ERIC Educational Resources Information Center

Machado, Juliana; Braga, Marco Antônio Barbosa

2016-01-01

A characterization of the modelling process in science is proposed for science education, based on Mario Bunge's ideas about the construction of models in science. Galileo's "Dialogues" are analysed as a potentially fruitful starting point to implement strategies aimed at modelling in the classroom in the light of that proposal. It is…

Comparing the Hydrologic and Watershed Processes between a Full Scale Stochastic Model Versus a Scaled Physical Model of Bell Canyon

NASA Astrophysics Data System (ADS)

Hernandez, K. F.; Shah-Fairbank, S.

2016-12-01

The San Dimas Experimental Forest has been designated as a research area by the United States Forest Service for use as a hydrologic testing facility since 1933 to investigate watershed hydrology of the 27 square mile land. Incorporation of a computer model provides validity to the testing of the physical model. This study focuses on San Dimas Experimental Forest's Bell Canyon, one of the triad of watersheds contained within the Big Dalton watershed of the San Dimas Experimental Forest. A scaled physical model was constructed of Bell Canyon to highlight watershed characteristics and each's effect on runoff. The physical model offers a comprehensive visualization of a natural watershed and can vary the characteristics of rainfall intensity, slope, and roughness through interchangeable parts and adjustments to the system. The scaled physical model is validated and calibrated through a HEC-HMS model to assure similitude of the system. Preliminary results of the physical model suggest that a 50-year storm event can be represented by a peak discharge of 2.2 X 10-3 cfs. When comparing the results to HEC-HMS, this equates to a flow relationship of approximately 1:160,000, which can be used to model other return periods. The completion of the Bell Canyon physical model can be used for educational instruction in the classroom, outreach in the community, and further research using the model as an accurate representation of the watershed present in the San Dimas Experimental Forest.

Methodologies for Development of Patient Specific Bone Models from Human Body CT Scans

NASA Astrophysics Data System (ADS)

Chougule, Vikas Narayan; Mulay, Arati Vinayak; Ahuja, Bharatkumar Bhagatraj

2016-06-01

This work deals with development of algorithm for physical replication of patient specific human bone and construction of corresponding implants/inserts RP models by using Reverse Engineering approach from non-invasive medical images for surgical purpose. In medical field, the volumetric data i.e. voxel and triangular facet based models are primarily used for bio-modelling and visualization, which requires huge memory space. On the other side, recent advances in Computer Aided Design (CAD) technology provides additional facilities/functions for design, prototyping and manufacturing of any object having freeform surfaces based on boundary representation techniques. This work presents a process to physical replication of 3D rapid prototyping (RP) physical models of human bone from various CAD modeling techniques developed by using 3D point cloud data which is obtained from non-invasive CT/MRI scans in DICOM 3.0 format. This point cloud data is used for construction of 3D CAD model by fitting B-spline curves through these points and then fitting surface between these curve networks by using swept blend techniques. This process also can be achieved by generating the triangular mesh directly from 3D point cloud data without developing any surface model using any commercial CAD software. The generated STL file from 3D point cloud data is used as a basic input for RP process. The Delaunay tetrahedralization approach is used to process the 3D point cloud data to obtain STL file. CT scan data of Metacarpus (human bone) is used as the case study for the generation of the 3D RP model. A 3D physical model of the human bone is generated on rapid prototyping machine and its virtual reality model is presented for visualization. The generated CAD model by different techniques is compared for the accuracy and reliability. The results of this research work are assessed for clinical reliability in replication of human bone in medical field.

On the deduction of chemical reaction pathways from measurements of time series of concentrations.

PubMed

Samoilov, Michael; Arkin, Adam; Ross, John

2001-03-01

We discuss the deduction of reaction pathways in complex chemical systems from measurements of time series of chemical concentrations of reacting species. First we review a technique called correlation metric construction (CMC) and show the construction of a reaction pathway from measurements on a part of glycolysis. Then we present two new improved methods for the analysis of time series of concentrations, entropy metric construction (EMC), and entropy reduction method (ERM), and illustrate (EMC) with calculations on a model reaction system. (c) 2001 American Institute of Physics.

The role of companionship, esteem, and informational support in explaining physical activity among young women in an online social network intervention.

PubMed

Cavallo, David N; Brown, Jane D; Tate, Deborah F; DeVellis, Robert F; Zimmer, Catherine; Ammerman, Alice S

2014-10-01

The primary objective of the current study was to examine the relationship between social support and physical activity within the theory of planned behavior (TPB) theoretical framework. This study used data from the Internet Support for Healthy Associations Promoting Exercise randomized controlled trial. A total of 134 female undergraduate students participated in the study, which included baseline and post measures of perceived social support for physical activity (esteem, informational, and companionship), TPB variables related to physical activity (perceived behavioral control, intention, and attitude), and physical activity behavior. Path analysis revealed a significant indirect relationship between change in companionship support and physical activity mediated by change in intention (.13, p < .01) and a significant direct relationship between change in esteem support and change in physical activity (.26, p = .03). The model explained 27% of the variance in physical activity and 59% of the variance in intention. Overall, change in social support exerted a small to medium amount of influence on change in physical activity in this modified TPB model when controlling for traditional model constructs. Encouraging companionship and esteem support should be considered as a strategy for increasing physical activity in this population.

Modelling, Visibility Testing and Projection of an Orthogonal Three Dimensional World in Support of a Single Camera Vision System

DTIC Science & Technology

1992-03-01

construction were completed and data, "’dm blue prints and physical measurements, was entered concurrent with the coding of routines for data retrieval. While...desirable for that view to accurately reflect what a person (or camera) would see if they were to stand at the same point in the physical world. To... physical dimensions. A parallel projection does not perform this scaling and is therefore not suitable to our application. B. GENERAL PERSPECTIVE

Viscoplastic Model Development with an Eye Toward Characterization

NASA Technical Reports Server (NTRS)

Freed, Alan D.; Walker, Kevin P.

1995-01-01

A viscoplastic theory is developed that reduces analytically to creep theory under steady-state conditions. A viscoplastic model is constructed within this theoretical framework by defining material functions that have close ties to the physics of inelasticity. As a consequence, this model is easily characterized-only steady-state creep data, monotonic stress-strain curves, and saturated stress-strain hysteresis loops are required.

The Evaluation of Modelling Competences: Difficulties and Potentials for the Learning of the Sciences

ERIC Educational Resources Information Center

Lopes, J. Bernardino; Costa, Nilza

2007-01-01

Modelling is an inherent process for the construction and use of science concepts that mobilize diverse specific competences. The aims of this work are to put forward a means of evaluating modelling competences that is relevant for physics teaching and science education research and to identify the potentials and constraints in the development of…

Reanalysis of the occurrence of back pain among construction workers: modelling for the interdependent effects of heavy physical work, earlier back accidents, and aging.

PubMed

Nurminen, M

1997-11-01

To re-examine the relation between heavy physical work and the occurrence of sciatic pain among construction workers reported previously to be absent in an epidemiological study. METHODS-Poisson log linear regression was used to model for the frequency of sciatic pain among concrete reinforcement workers and maintenance house painters with adjustment for the interactive effects of earlier back accidents and aging that modified the relation. Concrete reinforcement work not only had a direct effect on the frequency of sciatic pain, but it also contributed significantly to the risk indirectly through earlier back accidents. The risk of sciatic pain increased from age 25 to 54 in a different manner for a worker depending on his occupational group and record of back accidents. Epidemiological studies on low back pain need to be analysed with sound methodology. This is important in view of future meta-analyses that will be performed for the purpose of providing guidelines on the prevention of back disorders in heavy physical work.

Application of the Transtheoretical Model of behavior change to the physical activity behavior of WIC mothers.

PubMed

Fahrenwald, Nancy L; Walker, Susan Noble

2003-01-01

This descriptive-correlational study examined the Transtheoretical Model (TTM) of behavior change in relationship to the physical activity behavior of mothers receiving assistance from the Women, Infants, and Children program. A purposive sample (N = 30) of six women at each of the five stages of readiness for behavior change was used. Relationships between stage of behavior change (measured using the Stage of Exercise Adoption tool) and other TTM constructs were examined. The constructs and corresponding instruments included physical activity behavior (Seven-Day Physical Activity Recall), pros, cons, decisional balance (Exercise Benefits/Barriers Scale and two open-ended questions), self-efficacy (Self-efficacy for Exercise scale), and processes of behavior change (Processes of Exercise Adoption tool and the Social Support for Exercise scale). Significant relationships were found between stage of behavior change and two physical activity energy expenditure indices (rs = 0.71-0.73, p < 0.01), daily minutes of moderate to very hard physical activity (rs = 0.81, p < 0.01), pros (rs = 0.56, p < 0.01), cons (rs = -0.52, p < 0.05), decisional balance (rs = 0.56, p < 0.01), and self-efficacy (rs = 0.56, p < 0.01). Use of the 10 processes of change differed by stage of change. Pros to physical activity included a sense of accomplishment, increased strength, stress relief, and getting in shape after pregnancy. Cons included fatigue, childcare, and cold weather. Results support the TTM as relevant to WIC mothers and suggest strategies to increase physical activity in this population.

Construction of fuzzy spaces and their applications to matrix models

NASA Astrophysics Data System (ADS)

Abe, Yasuhiro

Quantization of spacetime by means of finite dimensional matrices is the basic idea of fuzzy spaces. There remains an issue of quantizing time, however, the idea is simple and it provides an interesting interplay of various ideas in mathematics and physics. Shedding some light on such an interplay is the main theme of this dissertation. The dissertation roughly separates into two parts. In the first part, we consider rather mathematical aspects of fuzzy spaces, namely, their construction. We begin with a review of construction of fuzzy complex projective spaces CP k (k = 1, 2, · · ·) in relation to geometric quantization. This construction facilitates defining symbols and star products on fuzzy CPk. Algebraic construction of fuzzy CPk is also discussed. We then present construction of fuzzy S 4, utilizing the fact that CP3 is an S2 bundle over S4. Fuzzy S4 is obtained by imposing an additional algebraic constraint on fuzzy CP3. Consequently it is proposed that coordinates on fuzzy S4 are described by certain block-diagonal matrices. It is also found that fuzzy S8 can analogously be constructed. In the second part of this dissertation, we consider applications of fuzzy spaces to physics. We first consider theories of gravity on fuzzy spaces, anticipating that they may offer a novel way of regularizing spacetime dynamics. We obtain actions for gravity on fuzzy S2 and on fuzzy CP3 in terms of finite dimensional matrices. Application to M(atrix) theory is also discussed. With an introduction of extra potentials to the theory, we show that it also has new brane solutions whose transverse directions are described by fuzzy S 4 and fuzzy CP3. The extra potentials can be considered as fuzzy versions of differential forms or fluxes, which enable us to discuss compactification models of M(atrix) theory. In particular, compactification down to fuzzy S4 is discussed and a realistic matrix model of M-theory in four-dimensions is proposed.

Admission Models for At-Risk Graduate Students in Different Academic Disciplines.

ERIC Educational Resources Information Center

Nelson, C. Van; Nelson, Jacquelyn S.; Malone, Bobby G.

In this study, models were constructed for eight academic areas, including applied sciences, communication sciences, education, physical sciences, life sciences, humanities and arts, psychology, and social sciences, to predict whether or not an at-risk graduate student would be successful in obtaining a master's degree. Records were available for…

Rasch Model Based Analysis of the Force Concept Inventory

ERIC Educational Resources Information Center

Planinic, Maja; Ivanjek, Lana; Susac, Ana

2010-01-01

The Force Concept Inventory (FCI) is an important diagnostic instrument which is widely used in the field of physics education research. It is therefore very important to evaluate and monitor its functioning using different tools for statistical analysis. One of such tools is the stochastic Rasch model, which enables construction of linear…

Modelling Question Difficulty in an A Level Physics Examination

ERIC Educational Resources Information Center

Crisp, Victoria; Grayson, Rebecca

2013-01-01

"Item difficulty modelling" is a technique used for a number of purposes such as to support future item development, to explore validity in relation to the constructs that influence difficulty and to predict the difficulty of items. This research attempted to explore the factors influencing question difficulty in a general qualification…

Construct-a-Boat. Science by Design Series.

ERIC Educational Resources Information Center

Baroway, William

This book is one of four books in the Science-by-Design Series created by TERC and funded by the National Science Foundation (NSF). It challenges high school students to investigate the physics of boat performance and work with systems and modeling. Through research, design, testing, and evaluation of a model boat, students experience the…

The Action--Reflection--Modelling (ARM) Pedagogical Approach for Teacher Education: A Malaysia-UK Project

ERIC Educational Resources Information Center

Jarvis, Joy; Dickerson, Claire; Thomas, Kit; Graham, Sally

2014-01-01

This article presents the Action--Reflection--Modelling (ARM) pedagogical approach for teacher education developed during a Malaysia-UK collaborative project to construct a Bachelor of Education (Honours) degree programme in Primary Mathematics, with English and Health and Physical Education as minor subjects. The degree programme was written…

Responses of experimental river corridors to engineered log jams

USDA-ARS?s Scientific Manuscript database

Physical models of the Big Sioux River, SD, were constructed to assess the impact on flow, drag, and bed erosion and deposition in response to the installation of two different types of engineered log jams (ELJs). A fixed-bed model focused on flow velocity and forces acting on an instrumented ELJ, a...

Peer Assessment with Online Tools to Improve Student Modeling

ERIC Educational Resources Information Center

Atkins, Leslie J.

2012-01-01

Introductory physics courses often require students to develop precise models of phenomena and represent these with diagrams, including free-body diagrams, light-ray diagrams, and maps of field lines. Instructors expect that students will adopt a certain rigor and precision when constructing these diagrams, but we want that rigor and precision to…

How-to-Do-It: A Physical Model Illustrating Protein Synthesis on the Ribosome.

ERIC Educational Resources Information Center

Rogerson, Allen C.; Cheney, Richard W., Jr.

1989-01-01

Describes a way to help students grasp intermediate steps in the movement and relationships of the various components involved in the addition of an amino acid to a nascent peptide chain. Includes drawings of the model in operation, construction details, and suggested shapes and labeling of components. (RT)

What do they know about Heat and Heat Conduction? A case study to excavate Pre-service Physics Teachers’ Mental Model in Heat and Heat Conduction

NASA Astrophysics Data System (ADS)

Sari, I. M.

2017-02-01

Teacher plays a crucial role in Education. Helping students construct scientifically mental model is one of obligation of Physics Education Department of Teacher Education Institute that produce physics teacher. Excavating students’ mental model is necessary to be done in physics education. This research was first to identify 23 physics students’ mental model of heat and heat conduction. A series of semi-structured interviews was conducted to excavate the students’ understanding of heat and mental models on heat conduction. The students who involved in this study come from different level from sophomore to master degree in Physics Education Department. This study adopted a constant comparison method to obtain the patterns of the participants’ responses through the students’ writing, drawing and verbal utterances. The framework for assessing mental model and the instruments were adopted and adapted from Chiou and Anderson (2010). We also compared the students’ understanding of heat and mental models on heat conduction. The result shows that Heat is treated as Intrinsic property, material substances, and caloric flow. None of students expressed heat as transfer of thermal energy. Moreover, there are two kinds of students’ fundamental component of mental model in heat conduction were found: medium and molecules. Students understanding of heat and fundamental components of mental model in heat conduction are not resulted from running mental model.

Prediction of physical workload in reduced gravity environments

NASA Technical Reports Server (NTRS)

Goldberg, Joseph H.

1987-01-01

The background, development, and application of a methodology to predict human energy expenditure and physical workload in low gravity environments, such as a Lunar or Martian base, is described. Based on a validated model to predict energy expenditures in Earth-based industrial jobs, the model relies on an elemental analysis of the proposed job. Because the job itself need not physically exist, many alternative job designs may be compared in their physical workload. The feasibility of using the model for prediction of low gravity work was evaluated by lowering body and load weights, while maintaining basal energy expenditure. Comparison of model results was made both with simulated low gravity energy expenditure studies and with reported Apollo 14 Lunar EVA expenditure. Prediction accuracy was very good for walking and for cart pulling on slopes less than 15 deg, but the model underpredicted the most difficult work conditions. This model was applied to example core sampling and facility construction jobs, as presently conceptualized for a Lunar or Martian base. Resultant energy expenditures and suggested work-rest cycles were well within the range of moderate work difficulty. Future model development requirements were also discussed.

Neutron Star Models in Alternative Theories of Gravity

NASA Astrophysics Data System (ADS)

Manolidis, Dimitrios

We study the structure of neutron stars in a broad class of alternative theories of gravity. In particular, we focus on Scalar-Tensor theories and f(R) theories of gravity. We construct static and slowly rotating numerical star models for a set of equations of state, including a polytropic model and more realistic equations of state motivated by nuclear physics. Observable quantities such as masses, radii, etc are calculated for a set of parameters of the theories. Specifically for Scalar-Tensor theories, we also calculate the sensitivities of the mass and moment of inertia of the models to variations in the asymptotic value of the scalar field at infinity. These quantities enter post-Newtonian equations of motion and gravitational waveforms of two body systems that are used for gravitational-wave parameter estimation, in order to test these theories against observations. The construction of numerical models of neutron stars in f(R) theories of gravity has been difficult in the past. Using a new formalism by Jaime, Patino and Salgado we were able to construct models with high interior pressure, namely pc > rho c/3, both for constant density models and models with a polytropic equation of state. Thus, we have shown that earlier objections to f(R) theories on the basis of the inability to construct viable neutron star models are unfounded.

Validity evidence for the adaptation of the State Mindfulness Scale for Physical Activity (SMS-PA) in Spanish youth.

PubMed

Ullrich-French, Sarah; González Hernández, Juan; Hidalgo Montesinos, María D

2017-02-01

Mindfulness is an increasingly popular construct with promise in enhancing multiple positive health outcomes. Physical activity is an important behavior for enhancing overall health, but no Spanish language scale exists to test how mindfulness during physical activity may facilitate physical activity motivation or behavior. This study examined the validity of a Spanish adaption of a new scale, the State Mindfulness Scale for Physical Activity, to assess mindfulness during a specific experience of physical activity. Spanish youths (N = 502) completed a cross-sectional survey of state mindfulness during physical activity and physical activity motivation regulations based on Self-Determination Theory. A high-order model fit the data well and supports the use of one general state mindfulness factor or the use of separate subscales of mindfulness of mental (e.g., thoughts, emotions) and body (physical movement, muscles) aspects of the experience. Internal consistency reliability was good for the general scale and both sub-scales. The pattern of correlations with motivation regulations provides further support for construct validity with significant and positive correlations with self-determined forms of motivation and significant and negative correlations with external regulation and amotivation. Initial validity evidence is promising for the use of the adapted measure.

A framework to enhance security of physically unclonable functions using chaotic circuits

NASA Astrophysics Data System (ADS)

Chen, Lanxiang

2018-05-01

As a new technique for authentication and key generation, physically unclonable function (PUF) has attracted considerable attentions, with extensive research results achieved already. To resist the popular machine learning modeling attacks, a framework to enhance the security of PUFs is proposed. The basic idea is to combine PUFs with a chaotic system of which the response is highly sensitive to initial conditions. For this framework, a specific construction which combines the common arbiter PUF circuit, a converter, and the Chua's circuit is given to implement a more secure PUF. Simulation experiments are presented to further validate the framework. Finally, some practical suggestions for the framework and specific construction are also discussed.

A process-oriented measure of habit strength for moderate-to-vigorous physical activity

PubMed Central

Grove, J. Robert; Zillich, Irja; Medic, Nikola

2014-01-01

Purpose: Habitual action is an important aspect of health behaviour, but the relevance of various habit strength indicators continues to be debated. This study focused specifically on moderate-to-vigorous physical activity (MVPA) and evaluated the construct validity of a framework emphasizing patterned action, stimulus-response bonding, automaticity, and negative consequences for nonperformance as indicators of habit strength for this form of exercise. Methods: Upper-level undergraduates (N = 124) provided demographic information and responded to questionnaire items assessing historical MVPA involvement, current MVPA involvement, and the four proposed habit strength dimensions. Factor analyses were used to examine the latent structure of the habit strength indicators, and the model's construct validity was evaluated via an examination of relationships with repetition history and current behaviour. Results: At a measurement level, findings indicated that the proposed four-component model possessed psychometric integrity as a coherent set of factors. Criterion-related validity was also demonstrated via significant changes in three of the four factors as a function of past involvement in MVPA and significant correlations with the frequency, duration, and intensity of current MVPA. Conclusions: These findings support the construct validity of this exercise habit strength model and suggest that it could provide a template for future research on how MVPA habits are developed and maintained. PMID:25750789

A process-oriented measure of habit strength for moderate-to-vigorous physical activity.

PubMed

Grove, J Robert; Zillich, Irja; Medic, Nikola

2014-01-01

Purpose : Habitual action is an important aspect of health behaviour, but the relevance of various habit strength indicators continues to be debated. This study focused specifically on moderate-to-vigorous physical activity (MVPA) and evaluated the construct validity of a framework emphasizing patterned action, stimulus-response bonding, automaticity, and negative consequences for nonperformance as indicators of habit strength for this form of exercise. Methods : Upper-level undergraduates ( N  = 124) provided demographic information and responded to questionnaire items assessing historical MVPA involvement, current MVPA involvement, and the four proposed habit strength dimensions. Factor analyses were used to examine the latent structure of the habit strength indicators, and the model's construct validity was evaluated via an examination of relationships with repetition history and current behaviour. Results : At a measurement level, findings indicated that the proposed four-component model possessed psychometric integrity as a coherent set of factors. Criterion-related validity was also demonstrated via significant changes in three of the four factors as a function of past involvement in MVPA and significant correlations with the frequency, duration, and intensity of current MVPA. Conclusions : These findings support the construct validity of this exercise habit strength model and suggest that it could provide a template for future research on how MVPA habits are developed and maintained.

The Mathematics of High School Physics

NASA Astrophysics Data System (ADS)

Kanderakis, Nikos

2016-10-01

In the seventeenth and eighteenth centuries, mathematicians and physical philosophers managed to study, via mathematics, various physical systems of the sublunar world through idealized and simplified models of these systems, constructed with the help of geometry. By analyzing these models, they were able to formulate new concepts, laws and theories of physics and then through models again, to apply these concepts and theories to new physical phenomena and check the results by means of experiment. Students' difficulties with the mathematics of high school physics are well known. Science education research attributes them to inadequately deep understanding of mathematics and mainly to inadequate understanding of the meaning of symbolic mathematical expressions. There seem to be, however, more causes of these difficulties. One of them, not independent from the previous ones, is the complex meaning of the algebraic concepts used in school physics (e.g. variables, parameters, functions), as well as the complexities added by physics itself (e.g. that equations' symbols represent magnitudes with empirical meaning and units instead of pure numbers). Another source of difficulties is that the theories and laws of physics are often applied, via mathematics, to simplified, and idealized physical models of the world and not to the world itself. This concerns not only the applications of basic theories but also all authentic end-of-the-chapter problems. Hence, students have to understand and participate in a complex interplay between physics concepts and theories, physical and mathematical models, and the real world, often without being aware that they are working with models and not directly with the real world.

State-Transition Structures in Physics and in Computation

NASA Astrophysics Data System (ADS)

Petri, C. A.

1982-12-01

In order to establish close connections between physical and computational processes, it is assumed that the concepts of “state” and of “transition” are acceptable both to physicists and to computer scientists, at least in an informal way. The aim of this paper is to propose formal definitions of state and transition elements on the basis of very low level physical concepts in such a way that (1) all physically possible computations can be described as embedded in physical processes; (2) the computational aspects of physical processes can be described on a well-defined level of abstraction; (3) the gulf between the continuous models of physics and the discrete models of computer science can be bridged by simple mathematical constructs which may be given a physical interpretation; (4) a combinatorial, nonstatistical definition of “information” can be given on low levels of abstraction which may serve as a basis to derive higher-level concepts of information, e.g., by a statistical or probabilistic approach. Conceivable practical consequences are discussed.

A conceptual model of independence and dependence for adults with chronic physical illness and disability.

PubMed

Gignac, M A; Cott, C

1998-09-01

This paper presents a conceptual model of physical independence and dependence as it relates to adult onset, chronic physical illness and disability. Physical independence and dependence are presented as two separate, continuous, and multiply determined constructs, and illustrations are provided of situations where people can be independent, dependent, not independent, or experience imposed dependence. The paper also discusses potential determinants of physical independence and dependence, including different domains of disability, the role of subjective perceptions, demographics, the physical and social/political environments, personal resources, attitudes and coping resources, illness and efficacy appraisals, and the nature of the assistive relationship. The paper extends work on physical independence and dependence by synthesizing the findings from previous studies and incorporating the findings from other relevant areas of research into the area. It also expands on the concepts of physical independence and dependence, as well as their determinants, and relates independence and dependence to other outcomes of interest such as service delivery.

Generalized two-dimensional chiral QED: Anomaly and exotic statistics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saradzhev, F.M.

1997-07-01

We study the influence of the anomaly on the physical quantum picture of the generalized chiral Schwinger model defined on S{sup 1}. We show that the anomaly (i) results in the background linearly rising electric field and (ii) makes the spectrum of the physical Hamiltonian nonrelativistic without a massive boson. The physical matter fields acquire exotic statistics. We construct explicitly the algebra of the Poincar{acute e} generators and show that it differs from the Poincar{acute e} one. We exhibit the role of the vacuum Berry phase in the failure of the Poincar{acute e} algebra to close. We prove that, inmore » spite of the background electric field, such phenomenon as the total screening of external charges characteristic for the standard Schwinger model takes place in the generalized chiral Schwinger model, too. {copyright} {ital 1997} {ital The American Physical Society}« less

Indirect Effects of Social Skills on Health Through Stress and Loneliness.

PubMed

Segrin, Chris

2017-10-20

The social skills deficit vulnerability model predicts that people with inadequate social skills are at risk for a range of psychosocial problems, especially when confronted with stress. People with poor social skills often experience stress and loneliness and these two constructs were tested as potential pathways by which the poor social skills confer a risk for compromised mental and physical health. An online survey was completed by 775 adults, aged 18-91. The sample matched national demographics for race/ethnicity and age, among those over 18. Structural equation modeling revealed indirect effects of social skills on both mental and physical health through both stress and loneliness. The models showed that poor social skills were associated with poor mental and physical health through elevated stress and increased loneliness. The findings reveal that social skills deficits are associated with physical as well as mental health problems.

The Blind Men and the Elephant: Identification of a Latent Maltreatment Construct for Youth in Foster Care

PubMed Central

Gabrielli, Joy; Jackson, Yo; Tunno, Angela M.; Hambrick, Erin P.

2017-01-01

Child maltreatment is a major public health concern due to its impact on developmental trajectories and consequences across mental and physical health outcomes. Operationalization of child maltreatment has been complicated, as research has used simple dichotomous counts to identification of latent class profiles. This study examines a latent measurement model assessed within foster youth inclusive of indicators of maltreatment chronicity and severity across four maltreatment types: physical, sexual, and psychological abuse, and neglect. Participants were 500 foster youth with a mean age of 12.99 years (SD = 2.95 years). Youth completed survey questions through a confidential audio computer-assisted self-interview program. A two-factor model with latent constructs of chronicity and severity of maltreatment revealed excellent fit across fit indices; however, the latent constructs were correlated .972. A one-factor model also demonstrated excellent model fit to the data (χ2 (16, n = 500) =28.087, p =.031, RMSEA (0.012 – 0.062) =.039, TLI =.990, CFI =.994, SRMR =.025) with a nonsignificant chi-square difference test comparing the one- and two-factor models. Invariance tests across age, gender, and placement type also were conducted with recommendations provided. Results suggest a single-factor latent model of maltreatment severity and chronicity can be attained. Thus, the maltreatment experiences reported by foster youth, though varied and complex, were captured in a model that may prove useful in later predictions of outcome behaviors. Appropriate identification of both the chronicity and severity of maltreatment inclusive of the range of maltreatment types remains a high priority for future research. PMID:28254690

Narrative Constructions for the Organization of Self Experience: Proof of Concept via Embodied Robotics.

PubMed

Mealier, Anne-Laure; Pointeau, Gregoire; Mirliaz, Solène; Ogawa, Kenji; Finlayson, Mark; Dominey, Peter F

2017-01-01

It has been proposed that starting from meaning that the child derives directly from shared experience with others, adult narrative enriches this meaning and its structure, providing causal links between unseen intentional states and actions. This would require a means for representing meaning from experience-a situation model-and a mechanism that allows information to be extracted from sentences and mapped onto the situation model that has been derived from experience, thus enriching that representation. We present a hypothesis and theory concerning how the language processing infrastructure for grammatical constructions can naturally be extended to narrative constructions to provide a mechanism for using language to enrich meaning derived from physical experience. Toward this aim, the grammatical construction models are augmented with additional structures for representing relations between events across sentences. Simulation results demonstrate proof of concept for how the narrative construction model supports multiple successive levels of meaning creation which allows the system to learn about the intentionality of mental states, and argument substitution which allows extensions to metaphorical language and analogical problem solving. Cross-linguistic validity of the system is demonstrated in Japanese. The narrative construction model is then integrated into the cognitive system of a humanoid robot that provides the memory systems and world-interaction required for representing meaning in a situation model. In this context proof of concept is demonstrated for how the system enriches meaning in the situation model that has been directly derived from experience. In terms of links to empirical data, the model predicts strong usage based effects: that is, that the narrative constructions used by children will be highly correlated with those that they experience. It also relies on the notion of narrative or discourse function words. Both of these are validated in the experimental literature.

Modal Damping Ratio and Optimal Elastic Moduli of Human Body Segments for Anthropometric Vibratory Model of Standing Subjects.

PubMed

Gupta, Manoj; Gupta, T C

2017-10-01

The present study aims to accurately estimate inertial, physical, and dynamic parameters of human body vibratory model consistent with physical structure of the human body that also replicates its dynamic response. A 13 degree-of-freedom (DOF) lumped parameter model for standing person subjected to support excitation is established. Model parameters are determined from anthropometric measurements, uniform mass density, elastic modulus of individual body segments, and modal damping ratios. Elastic moduli of ellipsoidal body segments are initially estimated by comparing stiffness of spring elements, calculated from a detailed scheme, and values available in literature for same. These values are further optimized by minimizing difference between theoretically calculated platform-to-head transmissibility ratio (TR) and experimental measurements. Modal damping ratios are estimated from experimental transmissibility response using two dominant peaks in the frequency range of 0-25 Hz. From comparison between dynamic response determined form modal analysis and experimental results, a set of elastic moduli for different segments of human body and a novel scheme to determine modal damping ratios from TR plots, are established. Acceptable match between transmissibility values calculated from the vibratory model and experimental measurements for 50th percentile U.S. male, except at very low frequencies, establishes the human body model developed. Also, reasonable agreement obtained between theoretical response curve and experimental response envelop for average Indian male, affirms the technique used for constructing vibratory model of a standing person. Present work attempts to develop effective technique for constructing subject specific damped vibratory model based on its physical measurements.

The influence of the enhanced vector meson sector on the properties of the matter of neutron stars.

PubMed

Bednarek, Ilona; Manka, Ryszard; Pienkos, Monika

2014-01-01

This paper gives an overview of the model of a neutron star with non-zero strangeness constructed within the framework of the nonlinear realization of the chiral SU(3)L x SU(3)R symmetry. The emphasis is put on the physical properties of the matter of a neutron star as well as on its internal structure. The obtained solution is particularly aimed at the problem of the construction of a theoretical model of a neutron star matter with hyperons that will give high value of the maximum mass.

Tracing How Normative Messages May Influence Physical Activity Intention.

PubMed

van Bavel, René; Esposito, Gabriele; Baranowski, Tom; Duch-Brown, Néstor

2017-04-01

Normative messages have been shown to increase intention to do physical activity. We traced how "positive" and "negative" normative messages influenced physical activity intention by comparing constructs of the model of goal-directed behavior with descriptive norms (MGDB + DNs) across control and treatment groups in an experiment. For this purpose, 16-24-year-old respondents (n = 1,200) in Bulgaria, Croatia, and Romania were asked about their age, sex, and levels of physical activity before being exposed to positive and negative normative messages and completing a questionnaire with MGDB + DNs scales. Different MGDB + DNs constructs were influenced by the normative messages: compared with the control, the negative message group showed stronger attitudes (p = .003) and the positive message group showed higher positive anticipated emotions (p = .005). The positive message's effect is consistent with the literature on conformity to social norms. The negative message's effect lends itself to interpretations based on social identity and deviance regulation theories.

Construct Validity of the SF-12v2 for the Homeless Population with Mental Illness: An Instrument to Measure Self-Reported Mental and Physical Health

PubMed Central

Chum, Antony; Skosireva, Anna; Tobon, Juliana; Hwang, Stephen

2016-01-01

Background Self-reported health measures are important indicators used by clinicians and researchers for the evaluation of health interventions, outcome assessment of clinical studies, and identification of health needs to improve resource allocation. However, the application of self-reported health measures relies on developing reliable and valid instruments that are suitable across diverse populations. The main objective of this study is to evaluate the construct validity of the SF-12v.2, an instrument for measuring self-rated physical and mental health, for homeless adults with mental illness. Various interventions have been aimed at improving the health of homeless people with mental illness, and the development of valid instruments to evaluate these interventions is imperative. Study Design We measured self-rated mental and physical health from a quota sample of 575 homeless people with mental illness using the SF-12v2, EQ-5D, Colorado Symptoms Index, and physical/mental health visual analogue scales. We examined the construct validity of the SF-12v2 through confirmatory factor analyses (CFA), and using ANOVA/correlation analyses to compare the SF-12v2 to the other instruments to ascertain discriminant/convergent validity. Results Our CFA showed that the measurement properties of the original SF-12v2 model had a mediocre fit with our empirical data (χ2 = 193.6, df = 43, p < .0001, CFI = 0.85, NFI = 0.83, RMSEA = 0.08). We demonstrate that changes based on theoretical rationale and previous studies can significantly improve the model, achieving an excellent fit in our final model (χ2 = 160.6, df = 48, p < .0001, CFI = 0.95, NFI = 0.95, RMSEA = 0.06). Our CFA results suggest that an alternative scoring method based on the new model may optimize health status measurement of a homeless population. Despite these issues, convergent and discriminant validity of the SF-12v2 (scored based on the original model) was supported through multiple comparisons with other instruments. Conclusion Our study demonstrates for the first time that the SF-12v2 is generally appropriate as a measure of physical and mental health status for a homeless population with mental illness. PMID:26938990

Construct Validity of the SF-12v2 for the Homeless Population with Mental Illness: An Instrument to Measure Self-Reported Mental and Physical Health.

PubMed

Chum, Antony; Skosireva, Anna; Tobon, Juliana; Hwang, Stephen

2016-01-01

Self-reported health measures are important indicators used by clinicians and researchers for the evaluation of health interventions, outcome assessment of clinical studies, and identification of health needs to improve resource allocation. However, the application of self-reported health measures relies on developing reliable and valid instruments that are suitable across diverse populations. The main objective of this study is to evaluate the construct validity of the SF-12v.2, an instrument for measuring self-rated physical and mental health, for homeless adults with mental illness. Various interventions have been aimed at improving the health of homeless people with mental illness, and the development of valid instruments to evaluate these interventions is imperative. We measured self-rated mental and physical health from a quota sample of 575 homeless people with mental illness using the SF-12v2, EQ-5D, Colorado Symptoms Index, and physical/mental health visual analogue scales. We examined the construct validity of the SF-12v2 through confirmatory factor analyses (CFA), and using ANOVA/correlation analyses to compare the SF-12v2 to the other instruments to ascertain discriminant/convergent validity. Our CFA showed that the measurement properties of the original SF-12v2 model had a mediocre fit with our empirical data (χ2 = 193.6, df = 43, p < .0001, CFI = 0.85, NFI = 0.83, RMSEA = 0.08). We demonstrate that changes based on theoretical rationale and previous studies can significantly improve the model, achieving an excellent fit in our final model (χ2 = 160.6, df = 48, p < .0001, CFI = 0.95, NFI = 0.95, RMSEA = 0.06). Our CFA results suggest that an alternative scoring method based on the new model may optimize health status measurement of a homeless population. Despite these issues, convergent and discriminant validity of the SF-12v2 (scored based on the original model) was supported through multiple comparisons with other instruments. Our study demonstrates for the first time that the SF-12v2 is generally appropriate as a measure of physical and mental health status for a homeless population with mental illness.

Factorial validity and internal consistency of the motivational climate in physical education scale.

PubMed

Soini, Markus; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami; Jaakkola, Timo

2014-01-01

The aim of the study was to examine the construct validity and internal consistency of the Motivational Climate in Physical Education Scale (MCPES). A key element of the development process of the scale was establishing a theoretical framework that integrated the dimensions of task- and ego involving climates in conjunction with autonomy, and social relatedness supporting climates. These constructs were adopted from the self-determination and achievement goal theories. A sample of Finnish Grade 9 students, comprising 2,594 girls and 1,803 boys, completed the 18-item MCPES during one physical education class. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate and ego-involving climate. Additionally, autonomy, social relatedness, and task- involving climates were significantly and strongly correlated with each other, whereas the ego- involving climate had low or negligible correlations with the other climate dimensions.The construct validity of the MCPES was analyzed using confirmatory factor analysis. The statistical fit of the four-factor model consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. The results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The Motivational Climate in Physical Education Scale can be considered as psychometrically valid tool to measure motivational climate in Finnish Grade 9 students. Key PointsThis study developed Motivational Climate in School Physical Education Scale (MCPES). During the development process of the scale, the theoretical framework using dimensions of task- and ego involving as well as autonomy, and social relatedness supporting climates was constructed. These constructs were adopted from the self-determination and achievement goal theories.The statistical fit of the four-factor model of the MCPES consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. Additionally, the results of the reliability analysis showed acceptable internal consistencies for all four dimensions.The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate.Autonomy, social relatedness, and task climate were significantly and strongly correlated with each other, whereas the ego climate factor had low or negligible correlations with the other three factors.

Factorial Validity and Internal Consistency of the Motivational Climate in Physical Education Scale

PubMed Central

Soini, Markus; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami; Jaakkola, Timo

2014-01-01

The aim of the study was to examine the construct validity and internal consistency of the Motivational Climate in Physical Education Scale (MCPES). A key element of the development process of the scale was establishing a theoretical framework that integrated the dimensions of task- and ego involving climates in conjunction with autonomy, and social relatedness supporting climates. These constructs were adopted from the self-determination and achievement goal theories. A sample of Finnish Grade 9 students, comprising 2,594 girls and 1,803 boys, completed the 18-item MCPES during one physical education class. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate and ego-involving climate. Additionally, autonomy, social relatedness, and task- involving climates were significantly and strongly correlated with each other, whereas the ego- involving climate had low or negligible correlations with the other climate dimensions.The construct validity of the MCPES was analyzed using confirmatory factor analysis. The statistical fit of the four-factor model consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. The results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The Motivational Climate in Physical Education Scale can be considered as psychometrically valid tool to measure motivational climate in Finnish Grade 9 students. Key Points This study developed Motivational Climate in School Physical Education Scale (MCPES). During the development process of the scale, the theoretical framework using dimensions of task- and ego involving as well as autonomy, and social relatedness supporting climates was constructed. These constructs were adopted from the self-determination and achievement goal theories. The statistical fit of the four-factor model of the MCPES consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. Additionally, the results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate. Autonomy, social relatedness, and task climate were significantly and strongly correlated with each other, whereas the ego climate factor had low or negligible correlations with the other three factors. PMID:24570617

Distribution system simulator

NASA Technical Reports Server (NTRS)

Bahrami, K. A.; Kirkham, H.; Rahman, S.

1986-01-01

In a series of tests performed under the Department of Energy auspices, power line carrier propagation was observed to be anomalous under certain circumstances. To investigate the cause, a distribution system simulator was constructed. The simulator was a physical simulator that accurately represented the distribution system from below power frequency to above 50 kHz. Effects such as phase-to-phase coupling and skin effect were modeled. Construction details of the simulator, and experimental results from its use are presented.

Physical approach to price momentum and its application to momentum strategy

NASA Astrophysics Data System (ADS)

Choi, Jaehyung

2014-12-01

We introduce various quantitative and mathematical definitions for price momentum of financial instruments. The price momentum is quantified with velocity and mass concepts originated from the momentum in physics. By using the physical momentum of price as a selection criterion, the weekly contrarian strategies are implemented in South Korea KOSPI 200 and US S&P 500 universes. The alternative strategies constructed by the physical momentum achieve the better expected returns and reward-risk measures than those of the traditional contrarian strategy in weekly scale. The portfolio performance is not understood by the Fama-French three-factor model.

Change in physical education motivation and physical activity behavior during middle school.

PubMed

Cox, Anne E; Smith, Alan L; Williams, Lavon

2008-11-01

To test a mediational model of the relationships among motivation-related variables in middle-school physical education and leisure-time physical activity behavior. Sixth- and seventh-grade physical education students from five middle schools in the midwest United States completed a survey containing measures of study variables on two occasions, 1 year apart. Motivation-related constructs positively predicted leisure-time physical activity behavior. Enjoyment of activities in physical education and physical activity during class mediated the relationship between self-determined motivation in physical education and leisure-time physical activity. Perceived competence, autonomy, and relatedness were important antecedent variables in the model, with autonomy and relatedness showing less stability over time and positively predicting self-determined motivation. Students' leisure-time physical activity is linked to motivation-related experiences in physical education. Perceptions of competence, autonomy, and relatedness, self-determined motivation, enjoyment, and physical activity in the physical education setting directly or indirectly predict leisure-time physical activity. The associations suggest that more adaptive motivation corresponds to transfer of behavior across contexts. Also, the findings suggest that the efficacy of school-based physical activity interventions, within and outside of school, is linked to the degree of support for students' self-determined motivation.

Well behaved anisotropic compact star models in general relativity

NASA Astrophysics Data System (ADS)

Jasim, M. K.; Maurya, S. K.; Gupta, Y. K.; Dayanandan, B.

2016-11-01

Anisotropic compact star models have been constructed by assuming a particular form of a metric function e^{λ}. We solved the Einstein field equations for determining the metric function e^{ν}. For this purpose we have assumed a physically valid expression of radial pressure (pr). The obtained anisotropic compact star model is representing the realistic compact objects such as PSR 1937 +21. We have done an extensive study about physical parameters for anisotropic models and found that these parameters are well behaved throughout inside the star. Along with these we have also determined the equation of state for compact star which gives the radial pressure is purely the function of density i.e. pr=f(ρ).

Astroparticle physics and cosmology.

PubMed

Mitton, Simon

2006-05-20

Astroparticle physics is an interdisciplinary field that explores the connections between the physics of elementary particles and the large-scale properties of the universe. Particle physicists have developed a standard model to describe the properties of matter in the quantum world. This model explains the bewildering array of particles in terms of constructs made from two or three quarks. Quarks, leptons, and three of the fundamental forces of physics are the main components of this standard model. Cosmologists have also developed a standard model to describe the bulk properties of the universe. In this new framework, ordinary matter, such as stars and galaxies, makes up only around 4% of the material universe. The bulk of the universe is dark matter (roughly 23%) and dark energy (about 73%). This dark energy drives an acceleration that means that the expanding universe will grow ever larger. String theory, in which the universe has several invisible dimensions, might offer an opportunity to unite the quantum description of the particle world with the gravitational properties of the large-scale universe.

Parallel State Space Construction for a Model Checking Based on Maximality Semantics

NASA Astrophysics Data System (ADS)

El Abidine Bouneb, Zine; Saīdouni, Djamel Eddine

2009-03-01

The main limiting factor of the model checker integrated in the concurrency verification environment FOCOVE [1, 2], which use the maximality based labeled transition system (noted MLTS) as a true concurrency model[3, 4], is currently the amount of available physical memory. Many techniques have been developed to reduce the size of a state space. An interesting technique among them is the alpha equivalence reduction. Distributed memory execution environment offers yet another choice. The main contribution of the paper is to show that the parallel state space construction algorithm proposed in [5], which is based on interleaving semantics using LTS as semantic model, may be adapted easily to the distributed implementation of the alpha equivalence reduction for the maximality based labeled transition systems.

Autotrophs' challenge to Dynamic Energy Budget theory: Comment on ;Physics of metabolic organization; by Marko Jusup et al.

NASA Astrophysics Data System (ADS)

Geček, Sunčana

2017-03-01

Jusup and colleagues in the recent review on physics of metabolic organization [1] discuss in detail motivational considerations and common assumptions of Dynamic Energy Budget (DEB) theory, supply readers with a practical guide to DEB-based modeling, demonstrate the construction and dynamics of the standard DEB model, and illustrate several applications. The authors make a step forward from the existing literature by seamlessly bridging over the dichotomy between (i) thermodynamic foundations of the theory (which are often more accessible and understandable to physicists and mathematicians), and (ii) the resulting bioenergetic models (mostly used by biologists in real-world applications).

An intrinsic poperty of memory of the Cellular automaton infrastructure of Nature leading to the organization of the physical world as an Internet o things; TOE = IOT

NASA Astrophysics Data System (ADS)

Berkovich, Simon

2015-04-01

The undamental advantage of a Cellular automaton construction foris that it can be viewed as an undetectable absolute frame o reference, in accordance with Lorentz-Poincare's interpretation.. The cellular automaton model for physical poblems comes upon two basic hurdles: (1) How to find the Elemental Rule that, and how to get non-locality from local transformations. Both problems are resolved considering the transfomation rule of mutual distributed synchronization Actually any information proessing device starts with a clocking system. and it turns out that ``All physical phenomena are different aspects of the high-level description of distributed mutual synchronization in a network of digital clocks''. Non-locality comes from two hugely different time-scales of signaling.. The universe is acombinines information and matter processes, These fast spreading diffusion wave solutions create the mechanism of the Holographic Universe. And thirdly Disengaged from synchronization, circular counters can perform memory functions by retaining phases of their oscillations, an idea of Von Neumann'. Thus, the suggested model generates the necessary constructs for the physical world as an Internet of Things. Life emerges due to the specifics of macromolecules that serve as communication means, with the holographic memory...

[New questionnaire to assess self-efficacy toward physical activity in children].

PubMed

Aedo, Angeles; Avila, Héctor

2009-10-01

To design a questionnaire for assessment of self-efficacy toward physical activity in school children, as well as to measure its construct validity, test-retest reliability, and internal consistency. A four-stage multimethod approach was used: (1) bibliographic research followed by exploratory study and the formulation of questions and responses based on a dichotomous scale of 14 items; (2) validation of the content by a panel of experts; (3) application of the preliminary version of the questionnaire to a sample of 900 school-aged children in Mexico City; and (4) determination of the construct validity, test-retest reliability, and internal consistency (Cronbach's alpha). Three factors were identified that explain 64.15% of the variance: the search for positive alternatives to physical activity, ability to deal with possible barriers to exercising, and expectations of skill or competence. The model was validated using the goodness of fit, and the result of 65% less than 0.05 indicated that the estimated factor model fit the data. Cronbach's consistency alpha was 0.733; test-retest reliability was 0.867. The scale designed has adequate reliability and validity. These results are a good indicator of self-efficacy toward physical activity in school children, which is important when developing programs intended to promote such behavior in this age group.

Healthy mind and body in a healthy work environment.

PubMed

Perez-Padron, Manuel; Bernabé, Eduardo; Gomez-Santos, Gladys; Tsakos, Georgios; Lozano de Luacess, Vicente

2010-12-01

To assess the relationship between psychological distress and physical somatic symptoms as well as work environment conditions in the diverse population of dentists based in the Canary Islands (Spain). 203 dentists officially registered with the local General Dental Councils, returned the questionnaire delivered by mail. Participants provided information on demographic characteristics, self-constructed questions like self-perceived environmental working conditions (location, access, temperature, humidity and pollution). They also completed the Spanish versions of the 12-item General Health Questionnaire (GHQ-12) and the revised version of the Symptom Checklist (SCL-90-R). The GHQ-12 was used to assess psychological distress and the somatic physical symptoms were assessed with the 12-item somatic subscale extracted from the SCL-90-R. Three different linear regression models were constructed. Psychological distress was positively related to somatic symptoms in all the models even after adjusting for sex and age. This association also remained significant for self-perceived environmental working conditions in the two final models. 23% of the dentists had psychological distress. The mean score for the SCL-90-R somatic subscale was 0.55 points (Standard Deviation: 0.50). Self-perceived environmental working conditions were also associated with the strong relationship found between psychological distress and physical somatic symptoms among dentists.

A student-centered approach for developing active learning: the construction of physical models as a teaching tool in medical physiology.

PubMed

Rezende-Filho, Flávio Moura; da Fonseca, Lucas José Sá; Nunes-Souza, Valéria; Guedes, Glaucevane da Silva; Rabelo, Luiza Antas

2014-09-15

Teaching physiology, a complex and constantly evolving subject, is not a simple task. A considerable body of knowledge about cognitive processes and teaching and learning methods has accumulated over the years, helping teachers to determine the most efficient way to teach, and highlighting student's active participation as a means to improve learning outcomes. In this context, this paper describes and qualitatively analyzes an experience of a student-centered teaching-learning methodology based on the construction of physiological-physical models, focusing on their possible application in the practice of teaching physiology. After having Physiology classes and revising the literature, students, divided in small groups, built physiological-physical models predominantly using low-cost materials, for studying different topics in Physiology. Groups were followed by monitors and guided by teachers during the whole process, finally presenting the results in a Symposium on Integrative Physiology. Along the proposed activities, students were capable of efficiently creating physiological-physical models (118 in total) highly representative of different physiological processes. The implementation of the proposal indicated that students successfully achieved active learning and meaningful learning in Physiology while addressing multiple learning styles. The proposed method has proved to be an attractive, accessible and relatively simple approach to facilitate the physiology teaching-learning process, while facing difficulties imposed by recent requirements, especially those relating to the use of experimental animals and professional training guidelines. Finally, students' active participation in the production of knowledge may result in a holistic education, and possibly, better professional practices.

Narrative Constructions for the Organization of Self Experience: Proof of Concept via Embodied Robotics

PubMed Central

Mealier, Anne-Laure; Pointeau, Gregoire; Mirliaz, Solène; Ogawa, Kenji; Finlayson, Mark; Dominey, Peter F.

2017-01-01

It has been proposed that starting from meaning that the child derives directly from shared experience with others, adult narrative enriches this meaning and its structure, providing causal links between unseen intentional states and actions. This would require a means for representing meaning from experience—a situation model—and a mechanism that allows information to be extracted from sentences and mapped onto the situation model that has been derived from experience, thus enriching that representation. We present a hypothesis and theory concerning how the language processing infrastructure for grammatical constructions can naturally be extended to narrative constructions to provide a mechanism for using language to enrich meaning derived from physical experience. Toward this aim, the grammatical construction models are augmented with additional structures for representing relations between events across sentences. Simulation results demonstrate proof of concept for how the narrative construction model supports multiple successive levels of meaning creation which allows the system to learn about the intentionality of mental states, and argument substitution which allows extensions to metaphorical language and analogical problem solving. Cross-linguistic validity of the system is demonstrated in Japanese. The narrative construction model is then integrated into the cognitive system of a humanoid robot that provides the memory systems and world-interaction required for representing meaning in a situation model. In this context proof of concept is demonstrated for how the system enriches meaning in the situation model that has been directly derived from experience. In terms of links to empirical data, the model predicts strong usage based effects: that is, that the narrative constructions used by children will be highly correlated with those that they experience. It also relies on the notion of narrative or discourse function words. Both of these are validated in the experimental literature. PMID:28861011

Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample.

PubMed

Vo, Phuong T; Bogg, Tim

2015-01-01

Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957), the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions), Social Cognitive Theory (self-efficacy, outcome expectancies), and the Transtheoretical Model (behavioral processes of change), and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks - the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model - termed the Disposition-Belief-Motivation model- is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement.

Constructing and predicting solitary pattern solutions for nonlinear time-fractional dispersive partial differential equations

NASA Astrophysics Data System (ADS)

Arqub, Omar Abu; El-Ajou, Ahmad; Momani, Shaher

2015-07-01

Building fractional mathematical models for specific phenomena and developing numerical or analytical solutions for these fractional mathematical models are crucial issues in mathematics, physics, and engineering. In this work, a new analytical technique for constructing and predicting solitary pattern solutions of time-fractional dispersive partial differential equations is proposed based on the generalized Taylor series formula and residual error function. The new approach provides solutions in the form of a rapidly convergent series with easily computable components using symbolic computation software. For method evaluation and validation, the proposed technique was applied to three different models and compared with some of the well-known methods. The resultant simulations clearly demonstrate the superiority and potentiality of the proposed technique in terms of the quality performance and accuracy of substructure preservation in the construct, as well as the prediction of solitary pattern solutions for time-fractional dispersive partial differential equations.

Studio Physics at the Colorado School of Mines: A model for iterative development and assessment

NASA Astrophysics Data System (ADS)

Kohl, Patrick; Kuo, Vincent

2009-05-01

The Colorado School of Mines (CSM) has taught its first-semester introductory physics course using a hybrid lecture/Studio Physics format for several years. Based on this previous success, over the past 18 months we have converted the second semester of our traditional calculus-based introductory physics course (Physics II) to a Studio Physics format. In this talk, we describe the recent history of the Physics II course and of Studio at Mines, discuss the PER-based improvements that we are implementing, and characterize our progress via several metrics, including pre/post Conceptual Survey of Electricity and Magnetism (CSEM) scores, Colorado Learning About Science Survey scores (CLASS), failure rates, and exam scores. We also report on recent attempts to involve students in the department's Senior Design program with our course. Our ultimate goal is to construct one possible model for a practical and successful transition from a lecture course to a Studio (or Studio-like) course.

How device-independent approaches change the meaning of physical theory

NASA Astrophysics Data System (ADS)

Grinbaum, Alexei

2017-05-01

Dirac sought an interpretation of mathematical formalism in terms of physical entities and Einstein insisted that physics should describe ;the real states of the real systems;. While Bell inequalities put into question the reality of states, modern device-independent approaches do away with the idea of entities: physical theory may contain no physical systems. Focusing on the correlations between operationally defined inputs and outputs, device-independent methods promote a view more distant from the conventional one than Einstein's 'principle theories' were from 'constructive theories'. On the examples of indefinite causal orders and almost quantum correlations, we ask a puzzling question: if physical theory is not about systems, then what is it about? Device-independent models suggest that physical theory can be 'about' languages.

How-to-Do-It: Muscle Activities that Stretch the Mind.

ERIC Educational Resources Information Center

Hanegan, James L.; McKean, Heather R.

1989-01-01

The construction of a wooden model of the musculoskeletal system which can be used to investigate the physical properties of muscles without sacrificing laboratory animals is presented. Six activities are included with answers. Additional activities are suggested. (CW)

Empirical flow parameters - a tool for hydraulic model validity assessment.

DOT National Transportation Integrated Search

2013-08-01

Data in Texas from the U.S. Geological Survey (USGS) physical stream flow and channel property measurements for gaging stations in the state of Texas were used to construct relations between observed stream flow, topographic slope, mean section veloc...

"Intelligent Ensemble" Projections of Precipitation and Surface Radiation in Support of Agricultural Climate Change Adaptation

NASA Technical Reports Server (NTRS)

Taylor, Patrick C.; Baker, Noel C.

2015-01-01

Earth's climate is changing and will continue to change into the foreseeable future. Expected changes in the climatological distribution of precipitation, surface temperature, and surface solar radiation will significantly impact agriculture. Adaptation strategies are, therefore, required to reduce the agricultural impacts of climate change. Climate change projections of precipitation, surface temperature, and surface solar radiation distributions are necessary input for adaption planning studies. These projections are conventionally constructed from an ensemble of climate model simulations (e.g., the Coupled Model Intercomparison Project 5 (CMIP5)) as an equal weighted average, one model one vote. Each climate model, however, represents the array of climate-relevant physical processes with varying degrees of fidelity influencing the projection of individual climate variables differently. Presented here is a new approach, termed the "Intelligent Ensemble, that constructs climate variable projections by weighting each model according to its ability to represent key physical processes, e.g., precipitation probability distribution. This approach provides added value over the equal weighted average method. Physical process metrics applied in the "Intelligent Ensemble" method are created using a combination of NASA and NOAA satellite and surface-based cloud, radiation, temperature, and precipitation data sets. The "Intelligent Ensemble" method is applied to the RCP4.5 and RCP8.5 anthropogenic climate forcing simulations within the CMIP5 archive to develop a set of climate change scenarios for precipitation, temperature, and surface solar radiation in each USDA Farm Resource Region for use in climate change adaptation studies.

Worksite interventions for preventing physical deterioration among employees in job-groups with high physical work demands: background, design and conceptual model of FINALE.

PubMed

Holtermann, Andreas; Jørgensen, Marie B; Gram, Bibi; Christensen, Jeanette R; Faber, Anne; Overgaard, Kristian; Ektor-Andersen, John; Mortensen, Ole S; Sjøgaard, Gisela; Søgaard, Karen

2010-03-09

A mismatch between individual physical capacities and physical work demands enhance the risk for musculoskeletal disorders, poor work ability and sickness absence, termed physical deterioration. However, effective intervention strategies for preventing physical deterioration in job groups with high physical demands remains to be established. This paper describes the background, design and conceptual model of the FINALE programme, a framework for health promoting interventions at 4 Danish job groups (i.e. cleaners, health-care workers, construction workers and industrial workers) characterized by high physical work demands, musculoskeletal disorders, poor work ability and sickness absence. A novel approach of the FINALE programme is that the interventions, i.e. 3 randomized controlled trials (RCT) and 1 exploratory case-control study are tailored to the physical work demands, physical capacities and health profile of workers in each job-group. The RCT among cleaners, characterized by repetitive work tasks and musculoskeletal disorders, aims at making the cleaners less susceptible to musculoskeletal disorders by physical coordination training or cognitive behavioral theory based training (CBTr). Because health-care workers are reported to have high prevalence of overweight and heavy lifts, the aim of the RCT is long-term weight-loss by combined physical exercise training, CBTr and diet. Construction work, characterized by heavy lifting, pushing and pulling, the RCT aims at improving physical capacity and promoting musculoskeletal and cardiovascular health. At the industrial work-place characterized by repetitive work tasks, the intervention aims at reducing physical exertion and musculoskeletal disorders by combined physical exercise training, CBTr and participatory ergonomics. The overall aim of the FINALE programme is to improve the safety margin between individual resources (i.e. physical capacities, and cognitive and behavioral skills) and physical work demands, and thereby reduce the physical deterioration in a long term perspective by interventions tailored for each respective job-group. The FINALE programme has the potential to provide evidence-based knowledge of significant importance for public health policy and health promotion strategies for employees at high risk for physical deterioration. ISRCTN96241850, NCT01015716 and NCT01007669.

Worksite interventions for preventing physical deterioration among employees in job-groups with high physical work demands: Background, design and conceptual model of FINALE

PubMed Central

2010-01-01

Background A mismatch between individual physical capacities and physical work demands enhance the risk for musculoskeletal disorders, poor work ability and sickness absence, termed physical deterioration. However, effective intervention strategies for preventing physical deterioration in job groups with high physical demands remains to be established. This paper describes the background, design and conceptual model of the FINALE programme, a framework for health promoting interventions at 4 Danish job groups (i.e. cleaners, health-care workers, construction workers and industrial workers) characterized by high physical work demands, musculoskeletal disorders, poor work ability and sickness absence. Methods/Design A novel approach of the FINALE programme is that the interventions, i.e. 3 randomized controlled trials (RCT) and 1 exploratory case-control study are tailored to the physical work demands, physical capacities and health profile of workers in each job-group. The RCT among cleaners, characterized by repetitive work tasks and musculoskeletal disorders, aims at making the cleaners less susceptible to musculoskeletal disorders by physical coordination training or cognitive behavioral theory based training (CBTr). Because health-care workers are reported to have high prevalence of overweight and heavy lifts, the aim of the RCT is long-term weight-loss by combined physical exercise training, CBTr and diet. Construction work, characterized by heavy lifting, pushing and pulling, the RCT aims at improving physical capacity and promoting musculoskeletal and cardiovascular health. At the industrial work-place characterized by repetitive work tasks, the intervention aims at reducing physical exertion and musculoskeletal disorders by combined physical exercise training, CBTr and participatory ergonomics. The overall aim of the FINALE programme is to improve the safety margin between individual resources (i.e. physical capacities, and cognitive and behavioral skills) and physical work demands, and thereby reduce the physical deterioration in a long term perspective by interventions tailored for each respective job-group. Discussion The FINALE programme has the potential to provide evidence-based knowledge of significant importance for public health policy and health promotion strategies for employees at high risk for physical deterioration. Trial registrations ISRCTN96241850, NCT01015716 and NCT01007669 PMID:20214807

A new physics-based modeling approach for tsunami-ionosphere coupling

NASA Astrophysics Data System (ADS)

Meng, X.; Komjathy, A.; Verkhoglyadova, O. P.; Yang, Y.-M.; Deng, Y.; Mannucci, A. J.

2015-06-01

Tsunamis can generate gravity waves propagating upward through the atmosphere, inducing total electron content (TEC) disturbances in the ionosphere. To capture this process, we have implemented tsunami-generated gravity waves into the Global Ionosphere-Thermosphere Model (GITM) to construct a three-dimensional physics-based model WP (Wave Perturbation)-GITM. WP-GITM takes tsunami wave properties, including the wave height, wave period, wavelength, and propagation direction, as inputs and time-dependently characterizes the responses of the upper atmosphere between 100 km and 600 km altitudes. We apply WP-GITM to simulate the ionosphere above the West Coast of the United States around the time when the tsunami associated with the March 2011 Tohuku-Oki earthquke arrived. The simulated TEC perturbations agree with Global Positioning System observations reasonably well. For the first time, a fully self-consistent and physics-based model has reproduced the GPS-observed traveling ionospheric signatures of an actual tsunami event.

Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample

PubMed Central

Vo, Phuong T.; Bogg, Tim

2015-01-01

Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957), the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions), Social Cognitive Theory (self-efficacy, outcome expectancies), and the Transtheoretical Model (behavioral processes of change), and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks – the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model – termed the Disposition-Belief-Motivation model– is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement. PMID:26300811

Modelling of project cash flow on construction projects in Malang city

NASA Astrophysics Data System (ADS)

Djatmiko, Bambang

2017-09-01

Contractors usually prepare a project cash flow (PCF) on construction projects. The flow of cash in and cash out within a construction project may vary depending on the owner, contract documents, and construction service providers who have their own authority. Other factors affecting the PCF are down payment, termyn, progress schedule, material schedule, equipment schedule, manpower schedules, and wages of workers and subcontractors. This study aims to describe the cash inflow and cash outflow based on the empirical data obtained from contractors, develop a PCF model based on Halpen & Woodhead's PCF model, and investigate whether or not there is a significant difference between the Halpen & Woodhead's PCF model and the empirical PCF model. Based on the researcher's observation, the PCF management has never been implemented by the contractors in Malang in serving their clients (owners). The research setting is in Malang City because physical development in all field and there are many new construction service providers. The findings in this current study are summarised as follows: 1) Cash in included current assets (20%), owner's down payment (20%), termyin I (5%-25%), termyin II (20%), termyin III (25%), termyin IV (25%) and retention (5%). Cash out included direct cost (65%), indirect cost (20%), and profit + informal cost(15%), 2)the construction work involving the empirical PCF model in this study was started with the funds obtained from DP or current assets and 3) The two models bear several similarities in the upward trends of direct cost, indirect cost, Pro Ic, progress billing, and S-curve. The difference between the two models is the occurrence of overdraft in the Halpen and Woodhead's PCF model only.

Determinants of Lifestyle Behavior in Iranian Adults with Prediabetes: Applying the Theory of Planned Behavior.

PubMed

Rahmati-Najarkolaei, Fatemeh; Pakpour, Amir H; Saffari, Mohsen; Hosseini, Mahboobeh Sadat; Hajizadeh, Fereshteh; Chen, Hui; Yekaninejad, Mir Saeed

2017-04-01

Prediabetic condition can lead to development of type 2 diabetes, especially in individuals who do not adhere to a healthy lifestyle. The aim of the present study was to investigate the socio-cognitive factors using the Theory of Planned Behavior (TPB) that may be associated with the choice of lifestyle in prediabetic patients. A prospective study with one-month follow up was designed to collect data from 350 individuals with prediabetic conditions. A questionnaire was used to collect the information, including demographic variables, exercise behavior, food consumption, as well as the constructs of the TPB (attitude, subjective norms, perceived behavioral control, and behavioral intention) regarding physical activity and dietary choice. The correlations between TPB variables and the dependent variables (dietary choice, physical activity) were assessed using Spearman correlation and multiple regression models. In total, 303 people participated. The mean age of the participants was 53.0 (SD 11.5) years and 42% were males. Significant correlations were found between all TPB constructs and both dependent variables (healthy eating and exercise behaviors) both at baseline and after one month (P < 0.01). The predictive validity of the TPB over time was proved for both dependent variables where past and future behaviors were significantly correlated with the constructs. Nearly 87% of the variance in exercise behavior and 72% of the variance in healthy eating behavior were explainable by TPB constructs. The TPB may be a useful model to predict behaviors of physical activity and dietary choice among prediabetic people. Therefore, it may be used to monitor lifestyle modification to prevent development of diabetes among people with prediabetic conditions.

Quasar Spectral Energy Distributions As A Function Of Physical Property

NASA Astrophysics Data System (ADS)

Townsend, Shonda; Ganguly, R.; Stark, M. A.; Derseweh, J. A.; Richmond, J. M.

2012-05-01

Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). In turn, models of outflows have shown particular sensitivity to the shape of the spectral energy distribution (SED), depending on the UV luminosity to transfer momentum to the gas, the X-ray luminosity to regulate how efficiently that transfer can be, etc. To investigate how SED changes with physical properties, we follow up on Richards et al. (2006), who constructed SEDs with varying luminosity. Here, we construct SEDs as a function of redshift, and physical property (black hole mass, bolometric luminosity, Eddington ratio) for volume limited samples drawn from the Sloan Digital Sky Survey, with photometry supplemented from 2MASS, WISE, GALEX, ROSAT, and Chandra. To estimate black hole masses, we adopt the scaling relations from Greene & Ho (2005) based on the H-alpha emission line FWHM. This requires redshifts less than 0.4. To construct volume-limited subsamples, we begin by adopting g=19.8 as a nominal limiting magnitude over which we are guaranteed to detect z<0.4 quasars. At redshift 0.4, we are complete down to Mg=-21.8, which yields 3300 objects from Data Release 7. At z=0.1, we are complete down to Mg=-18.5. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 09-ADP09-0016 issued through the Astrophysics Data Analysis Program.

Gene-environment interactions and construct validity in preclinical models of psychiatric disorders.

PubMed

Burrows, Emma L; McOmish, Caitlin E; Hannan, Anthony J

2011-08-01

The contributions of genetic risk factors to susceptibility for brain disorders are often so closely intertwined with environmental factors that studying genes in isolation cannot provide the full picture of pathogenesis. With recent advances in our understanding of psychiatric genetics and environmental modifiers we are now in a position to develop more accurate animal models of psychiatric disorders which exemplify the complex interaction of genes and environment. Here, we consider some of the insights that have emerged from studying the relationship between defined genetic alterations and environmental factors in rodent models. A key issue in such animal models is the optimization of construct validity, at both genetic and environmental levels. Standard housing of laboratory mice and rats generally includes ad libitum food access and limited opportunity for physical exercise, leading to metabolic dysfunction under control conditions, and thus reducing validity of animal models with respect to clinical populations. A related issue, of specific relevance to neuroscientists, is that most standard-housed rodents have limited opportunity for sensory and cognitive stimulation, which in turn provides reduced incentive for complex motor activity. Decades of research using environmental enrichment has demonstrated beneficial effects on brain and behavior in both wild-type and genetically modified rodent models, relative to standard-housed littermate controls. One interpretation of such studies is that environmentally enriched animals more closely approximate average human levels of cognitive and sensorimotor stimulation, whereas the standard housing currently used in most laboratories models a more sedentary state of reduced mental and physical activity and abnormal stress levels. The use of such standard housing as a single environmental variable may limit the capacity for preclinical models to translate into successful clinical trials. Therefore, there is a need to optimize 'environmental construct validity' in animal models, while maintaining comparability between laboratories, so as to ensure optimal scientific and medical outcomes. Utilizing more sophisticated models to elucidate the relative contributions of genetic and environmental factors will allow for improved construct, face and predictive validity, thus facilitating the identification of novel therapeutic targets. Copyright © 2010 Elsevier Inc. All rights reserved.

Physicochemical and osteoplastic characteristics of 3D printed bone grafts based on synthetic calcium phosphates and natural polymers

NASA Astrophysics Data System (ADS)

Nezhurina, E. K.; Karalkin, P. A.; Komlev, V. S.; Sviridova, I. K.; Kirsanova, V. A.; Akhmedova, S. A.; Shanskiy, Ya D.; Fedotov, A. Yu; Barinov, S. M.; Sergeeva, N. S.

2018-04-01

A creation of personalized implants for regeneration of bone tissue seems to be a very promising biomedical technological approach. We have studied the physicochemical characteristics, cyto- and biocompatibility of three-dimensional constructs based on sodium alginate and gelatin in combination with 2 types of calcium phosphate (tricalcium phosphate or octacalcium phosphate) obtained by inkjet 3D printing. In our experiments, we have studied the physical and chemical properties of the constructs – their porosity, chemical composition, microarchitecture of the surface and mechanical elasticity. The cytocompatibility of 3D constructs and matrix-for-cell properties were investigated in vitro on a model of human osteosarcoma MG-63 cell line by means of MTT assay. The biocompatibility of 3D constructs was studied on the model of subcutaneous implantation in mice up to 12 weeks. All types of 3D constructs were cytocompatible in vitro, demonstrated good matrix-for-cells properties, and had supported cell proliferation for 2 weeks. In results of subcutaneous in vivo test all constructs demonstrated biocompatibility with slow bioresorption of organic and inorganic components. Osteogenesis proceeded more actively in rat tibia model defects (marginal excision), substituted by 3D printed 3-component implants based on alginate, gelatin and octacalcium phosphate.

Utility of stages of change construct in the planning of physical activity interventions among playgroup mothers.

PubMed

Jones, Carlie; Jancey, Jonine; Howat, Peter; Dhaliwal, Satvinder; Burns, Sharyn; McManus, Alexandra; Hills, Andrew P; Anderson, Annie S

2013-07-29

The objective of this research was to assess the physical activity levels among a unique cohort of Western Australian (WA) mothers with young children who attend a WA Playgroup. Associated factors were also investigated, including self-efficacy for physical activity, social support for exercise, relevant socio-demographic correlates, as well as the stages of change construct within the Transtheoretical Model (TTM). 421 women completed a questionnaire assessing physical activity behaviours. Of these, 368 participants completed the relevant physical activity evaluation items. 82.5% and 17.5% of the sample were classified as active and inactive, respectively. Associations between physical activity status and exercise stage of change were found. Additional associations were established for partner support and self-efficacy for physical activity. The majority of the sample was classified as active. Despite the high percentage of active participants, this study confirms the usefulness of the stages of change measure in that it can be utilised by health promotion practitioners to report physical activity behaviour and develop appropriate intervention strategies among a time poor and hard to reach population. Specifically the results are relevant to mothers in over 16,000 WA families who are involved with Playgroup WA programs. Interventions aimed at improving physical activity levels in mothers with young children should also consider the need to improve self-efficacy and social support.

Modeling the Effects of Lipid Composition on Stratum Corneum Bilayers Using Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Huzil, J. Torin; Sivaloganathan, Siv; Kohandel, Mohammad; Foldvari, Marianna

2011-11-01

The advancement of dermal and transdermal drug delivery requires the development of delivery systems that are suitable for large protein and nucleic acid-based therapeutic agents. However, a complete mechanistic understanding of the physical barrier properties associated with the epidermis, specifically the membrane structures within the stratum corneum, has yet to be developed. Here, we describe the assembly and computational modeling of stratum corneum lipid bilayers constructed from varying ratios of their constituent lipids (ceramide, free fatty acids and cholesterol) to determine if there is a difference in the physical properties of stratum corneum compositions.

Geomagnetic field models incorporating physical constraints on the secular variation

NASA Technical Reports Server (NTRS)

Constable, Catherine; Parker, Robert L.

1993-01-01

This proposal has been concerned with methods for constructing geomagnetic field models that incorporate physical constraints on the secular variation. The principle goal that has been accomplished is the development of flexible algorithms designed to test whether the frozen flux approximation is adequate to describe the available geomagnetic data and their secular variation throughout this century. These have been applied to geomagnetic data from both the early and middle part of this century and convincingly demonstrate that there is no need to invoke violations of the frozen flux hypothesis in order to satisfy the available geomagnetic data.

A new exact anisotropic solution of embedding class one

NASA Astrophysics Data System (ADS)

Maurya, S. K.; Gupta, Y. K.; T. T., Smitha; Rahaman, Farook

2016-07-01

We have presented a new anisotropic solution of Einstein's field equations for compact-star models. Einstein's field equations are solved by using the class-one condition (S.N. Pandey, S.P. Sharma, Gen. Relativ. Gravit. 14, 113 (1982)). We constructed the expression for the anisotropy factor ( Δ by using the pressure anisotropy condition and thereafter we obtained the physical parameters like energy density, radial and transverse pressure. These models parameters are well-behaved inside the star and satisfy all the required physical conditions. Also we observed the very interesting result that all physical parameters depend upon the anisotropy factor ( Δ. The mass and radius of the present compact-star models are quite compatible with the observational astrophysical compact stellar objects like Her X-1, RXJ 1856-37, SAX J1808.4-3658(SS1), SAX J1808.4-3658(SS2).

Comment of "Event-based soil loss models for construction sites" by Trenouth and Gharabaghi, J. Hydrol. doi: 10.1016/jhydrol.2015.03.010

NASA Astrophysics Data System (ADS)

Kinnell, P. I. A.

2015-09-01

Trenouth and Gharabaghi (2015) present two models which replace the EI30 index used as the event erosivity index in the USLE/RUSLE with ones that include runoff and values of EI30 to powers that differ for 1.0 as the event erosivity factor in modelling soil loss for construction sites. Their analysis on the application of these models focused on data from 5 locations as a whole but did not show how the models worked at each location. Practically, the ability to predict sediment yields at a specific location is more relevant than the capacity of a model to predict sediment yields globally. Also, the mathematical structure of their proposed models shows little regard to the physical processes involved in causing erosion and sediment yield. There is still the need to develop event-based empirical models for construction sites that are robust because they give proper consideration to the erosion process involved, and take account of the fact that sediment yield is usually determined from measurements of suspended load whereas soil loss at the scale for which the USLE/RUSLE model was developed includes both suspended load and bed load.

Evaluation of the Growth Environment of a Hydrostatic Force Bioreactor for Preconditioning of Tissue-Engineered Constructs

PubMed Central

Reinwald, Yvonne; Leonard, Katherine H.L.; Henstock, James R.; Whiteley, Jonathan P.; Osborne, James M.; Waters, Sarah L.; Levesque, Philippe

2015-01-01

Bioreactors have been widely acknowledged as valuable tools to provide a growth environment for engineering tissues and to investigate the effect of physical forces on cells and cell-scaffold constructs. However, evaluation of the bioreactor environment during culture is critical to defining outcomes. In this study, the performance of a hydrostatic force bioreactor was examined by experimental measurements of changes in dissolved oxygen (O2), carbon dioxide (CO2), and pH after mechanical stimulation and the determination of physical forces (pressure and stress) in the bioreactor through mathematical modeling and numerical simulation. To determine the effect of hydrostatic pressure on bone formation, chick femur skeletal cell-seeded hydrogels were subjected to cyclic hydrostatic pressure at 0–270 kPa and 1 Hz for 1 h daily (5 days per week) over a period of 14 days. At the start of mechanical stimulation, dissolved O2 and CO2 in the medium increased and the pH of the medium decreased, but remained within human physiological ranges. Changes in physiological parameters (O2, CO2, and pH) were reversible when medium samples were placed in a standard cell culture incubator. In addition, computational modeling showed that the distribution and magnitude of physical forces depends on the shape and position of the cell-hydrogel constructs in the tissue culture format. Finally, hydrostatic pressure was seen to enhance mineralization of chick femur skeletal cell-seeded hydrogels. PMID:24967717

Evaluation of the growth environment of a hydrostatic force bioreactor for preconditioning of tissue-engineered constructs.

PubMed

Reinwald, Yvonne; Leonard, Katherine H L; Henstock, James R; Whiteley, Jonathan P; Osborne, James M; Waters, Sarah L; Levesque, Philippe; El Haj, Alicia J

2015-01-01

Bioreactors have been widely acknowledged as valuable tools to provide a growth environment for engineering tissues and to investigate the effect of physical forces on cells and cell-scaffold constructs. However, evaluation of the bioreactor environment during culture is critical to defining outcomes. In this study, the performance of a hydrostatic force bioreactor was examined by experimental measurements of changes in dissolved oxygen (O2), carbon dioxide (CO2), and pH after mechanical stimulation and the determination of physical forces (pressure and stress) in the bioreactor through mathematical modeling and numerical simulation. To determine the effect of hydrostatic pressure on bone formation, chick femur skeletal cell-seeded hydrogels were subjected to cyclic hydrostatic pressure at 0-270 kPa and 1 Hz for 1 h daily (5 days per week) over a period of 14 days. At the start of mechanical stimulation, dissolved O2 and CO2 in the medium increased and the pH of the medium decreased, but remained within human physiological ranges. Changes in physiological parameters (O2, CO2, and pH) were reversible when medium samples were placed in a standard cell culture incubator. In addition, computational modeling showed that the distribution and magnitude of physical forces depends on the shape and position of the cell-hydrogel constructs in the tissue culture format. Finally, hydrostatic pressure was seen to enhance mineralization of chick femur skeletal cell-seeded hydrogels.

Short- and long-term theory-based predictors of physical activity in women who participated in a weight-management program.

PubMed

Wasserkampf, A; Silva, M N; Santos, I C; Carraça, E V; Meis, J J M; Kremers, S P J; Teixeira, P J

2014-12-01

This study analyzed psychosocial predictors of the Theory of Planned Behavior (TPB) and Self-Determination Theory (SDT) and evaluated their associations with short- and long-term moderate plus vigorous physical activity (MVPA) and lifestyle physical activity (PA) outcomes in women who underwent a weight-management program. 221 participants (age 37.6 ± 7.02 years) completed a 12-month SDT-based lifestyle intervention and were followed-up for 24 months. Multiple linear regression analyses tested associations between psychosocial variables and self-reported short- and long-term PA outcomes. Regression analyses showed that control constructs of both theories were significant determinants of short- and long-term MVPA, whereas affective and self-determination variables were strong predictors of short- and long-term lifestyle PA. Regarding short-term prediction models, TPB constructs were stronger in predicting MVPA, whereas SDT was more effective in predicting lifestyle PA. For long-term models, both forms of PA were better predicted by SDT in comparison to TPB. These results highlight the importance of comparing health behavior theories to identify the mechanisms involved in the behavior change process. Control and competence constructs are crucial during early adoption of structured PA behaviors, whereas affective and intrinsic sources of motivation are more involved in incidental types of PA, particularly in relation to behavioral maintenance. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Effects of Evaluative vs. Co-Constructive Interactions on Learning in Physics

ERIC Educational Resources Information Center

Toczek, Marie-Christine; Morge, Ludovic

2009-01-01

We conducted an experimental study to assess the effects of two physics-learning situations that differed in the type of teacher-student interactions that took place: evaluative or co-constructive. As found in various studies on physics teaching and social psychology, the results showed that co-constructive interactions generated a more effective…

Undergraduate Student Construction and Interpretation of Graphs in Physics Lab Activities

ERIC Educational Resources Information Center

Nixon, Ryan S.; Godfrey, T. J.; Mayhew, Nicholas T.; Wiegert, Craig C.

2016-01-01

Lab activities are an important element of an undergraduate physics course. In these lab activities, students construct and interpret graphs in order to connect the procedures of the lab with an understanding of the related physics concepts. This study investigated undergraduate students' construction and interpretation of graphs with best-fit…

What Is Mathematical Modelling? Exploring Prospective Teachers' Use of Experiments to Connect Mathematics to the Study of Motion

ERIC Educational Resources Information Center

Carrejo, David J.; Marshall, Jill

2007-01-01

This paper focuses on the construction, development, and use of mathematical models by prospective science and mathematics teachers enrolled in a university physics course. By studying their involvement in an inquiry-based, experimental approach to learning kinematics, we address a fundamental question about the meaning and role of abstraction in…

Shadow poles in coupled-channel problems calculated with the Berggren basis

NASA Astrophysics Data System (ADS)

Id Betan, R. M.; Kruppa, A. T.; Vertse, T.

2018-02-01

Background: In coupled-channels models the poles of the scattering S matrix are located on different Riemann sheets. Physical observables are affected mainly by poles closest to the physical region but sometimes shadow poles have considerable effect too. Purpose: The purpose of this paper is to show that in coupled-channels problems all poles of the S matrix can be located by an expansion in terms of a properly constructed complex-energy basis. Method: The Berggren basis is used for expanding the coupled-channels solutions. Results: The locations of the poles of the S matrix for the Cox potential, constructed for coupled-channels problems, were numerically calculated and compared with the exact ones. In a nuclear physics application the Jπ=3 /2+ resonant poles of 5He were calculated in a phenomenological two-channel model. The properties of both the normal and shadow resonances agree with previous findings. Conclusions: We have shown that, with an appropriately chosen Berggren basis, all poles of the S matrix including the shadow poles can be determined. We have found that the shadow pole of 5He migrates between Riemann sheets if the coupling strength is varied.

Physical and Constructive (Limiting) Criterions of Gear Wheels Wear

NASA Astrophysics Data System (ADS)

Fedorov, S. V.

2018-01-01

We suggest using a generalized model of friction - the model of elastic-plastic deformation of the body element, which is located on the surface of the friction pairs. This model is based on our new engineering approach to the problem of friction-triboergodynamics. Friction is examined as transformative and dissipative process. Structural-energetic interpretation of friction as a process of elasto-plastic deformation and fracture contact volumes is proposed. The model of Hertzian (heavy-loaded) friction contact evolution is considered. The least wear particle principle is formulated. It is mechanical (nano) quantum. Mechanical quantum represents the least structural form of solid material body in conditions of friction. It is dynamic oscillator of dissipative friction structure and it can be examined as the elementary nanostructure of metal’s solid body. At friction in state of most complete evolution of elementary tribosystem (tribocontact) all mechanical quanta (subtribosystems) with the exception of one, elasticity and reversibly transform energy of outer impact (mechanic movement). In these terms only one mechanical quantum is the lost - standard of wear. From this position we can consider the physical criterion of wear and the constructive (limiting) criterion of gear teeth and other practical examples of tribosystems efficiency with new tribology notion - mechanical (nano) quantum.

[Advance in researches on the effect of forest on hydrological process].

PubMed

Zhang, Zhiqiang; Yu, Xinxiao; Zhao, Yutao; Qin, Yongsheng

2003-01-01

According to the effects of forest on hydrological process, forest hydrology can be divided into three related aspects: experimental research on the effects of forest changing on hydrological process quantity and water quality; mechanism study on the effects of forest changing on hydrological cycle, and establishing and exploitating physical-based distributed forest hydrological model for resource management and engineering construction. Orientation experiment research can not only support the first-hand data for forest hydrological model, but also make clear the precipitation-runoff mechanisms. Research on runoff mechanisms can be valuable for the exploitation and improvement of physical based hydrological models. Moreover, the model can also improve the experimental and runoff mechanism researches. A review of above three aspects are summarized in this paper.

Designing of plant artificial chromosome (PAC) by using the Chlorella smallest chromosome as a model system.

PubMed

Noutoshi, Y; Arai, R; Fujie, M; Yamada, T

1997-01-01

As a model for plant-type chromosomes, we have been characterizing molecular organization of the Chlorella vulgaris C-169 chromosome I. To identify chromosome structural elements including the centromeric region and replication origins, we constructed a chromosome I specific cosmid library and aligned each cosmid clones to generate contigs. So far, more than 80% of the entire chromosome I has been covered. A complete clonal physical reconstitution of chromosome I provides information on the structure and genomic organization of plant genome. We propose our strategy to construct an artificial chromosome by assembling the functional chromosome structural elements identified on Chrorella chromosome I.

Prospective elementary teachers' perceptions of the processes of modeling: A case study

NASA Astrophysics Data System (ADS)

Fazio, Claudio; di Paola, Benedetto; Guastella, Ivan

2012-06-01

In this paper we discuss a study on the approaches to modeling of students of the 4-year elementary school teacher program at the University of Palermo, Italy. The answers to a specially designed questionnaire are analyzed on the basis of an a priori analysis made using a general scheme of reference on the epistemology of mathematics and physics. The study is performed by using quantitative data analysis methods, i.e. factorial analysis of the correspondences and implicative analysis. A qualitative analysis of key words and terms used by students during interviews is also used to examine some aspects that emerged from the quantitative analysis. The students have been classified on the basis of their different epistemological approaches to knowledge construction, and implications between different conceptual strategies used to answer the questionnaire have been highlighted. The study’s conclusions are consistent with previous research, but the use of quantitative data analysis allowed us to classify the students into three “profiles” related to different epistemological approaches to knowledge construction, and to show the implications of the different conceptual strategies used to answer the questionnaire, giving an estimation of the classification or implication “strength.” Some hints on how a course for elementary school physics and mathematics education can be planned to orient the future teachers to the construction of models of explanation are reported.

Construction of ground-state preserving sparse lattice models for predictive materials simulations

NASA Astrophysics Data System (ADS)

Huang, Wenxuan; Urban, Alexander; Rong, Ziqin; Ding, Zhiwei; Luo, Chuan; Ceder, Gerbrand

2017-08-01

First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground states. However, despite recent advances, the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation, since this property is not guaranteed by default. In this paper, we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference data. The method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model parameters. The robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes, i.e., Li2xFe2(1-x)O2 and Li2xTi2(1-x)O2, for which the construction of cluster expansion models with compressive sensing alone has proven to be challenging. We demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction, but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative refinement. This method provides a general tool for building robust, compressed and constrained physical models with predictive power.

Shadows constructing a relationship between light and color pigments by physical and mathematical perspectives

NASA Astrophysics Data System (ADS)

Yurumezoglu, Kemal; Karabey, Burak; Yigit Koyunkaya, Melike

2017-03-01

Full shadows, partial shadows and multilayer shadows are explained based on the phenomenon of the linear dispersion of light. This paper focuses on progressing the understanding of shadows from physical and mathematical perspectives. A significant relationship between light and color pigments is demonstrated with the help of the concept of sets. This integration of physical and mathematical reasoning not only manages an operational approach to the concept of shadows, it also outputs a model that can be used in science, technology, engineering and mathematics (STEM) curricula by providing a concrete and physical example for abstract concept of the empty set.

Prototyping of cerebral vasculature physical models.

PubMed

Khan, Imad S; Kelly, Patrick D; Singer, Robert J

2014-01-01

Prototyping of cerebral vasculature models through stereolithographic methods have the ability to accurately depict the 3D structures of complicated aneurysms with high accuracy. We describe the method to manufacture such a model and review some of its uses in the context of treatment planning, research, and surgical training. We prospectively used the data from the rotational angiography of a 40-year-old female who presented with an unruptured right paraclinoid aneurysm. The 3D virtual model was then converted to a physical life-sized model. The model constructed was shown to be a very accurate depiction of the aneurysm and its associated vasculature. It was found to be useful, among other things, for surgical training and as a patient education tool. With improving and more widespread printing options, these models have the potential to become an important part of research and training modalities.

lidar change detection using building models

NASA Astrophysics Data System (ADS)

Kim, Angela M.; Runyon, Scott C.; Jalobeanu, Andre; Esterline, Chelsea H.; Kruse, Fred A.

2014-06-01

Terrestrial LiDAR scans of building models collected with a FARO Focus3D and a RIEGL VZ-400 were used to investigate point-to-point and model-to-model LiDAR change detection. LiDAR data were scaled, decimated, and georegistered to mimic real world airborne collects. Two physical building models were used to explore various aspects of the change detection process. The first model was a 1:250-scale representation of the Naval Postgraduate School campus in Monterey, CA, constructed from Lego blocks and scanned in a laboratory setting using both the FARO and RIEGL. The second model at 1:8-scale consisted of large cardboard boxes placed outdoors and scanned from rooftops of adjacent buildings using the RIEGL. A point-to-point change detection scheme was applied directly to the point-cloud datasets. In the model-to-model change detection scheme, changes were detected by comparing Digital Surface Models (DSMs). The use of physical models allowed analysis of effects of changes in scanner and scanning geometry, and performance of the change detection methods on different types of changes, including building collapse or subsistence, construction, and shifts in location. Results indicate that at low false-alarm rates, the point-to-point method slightly outperforms the model-to-model method. The point-to-point method is less sensitive to misregistration errors in the data. Best results are obtained when the baseline and change datasets are collected using the same LiDAR system and collection geometry.

Materials and techniques for model construction

NASA Technical Reports Server (NTRS)

Wigley, D. A.

1985-01-01

The problems confronting the designer of models for cryogenic wind tunnel models are discussed with particular reference to the difficulties in obtaining appropriate data on the mechanical and physical properties of candidate materials and their fabrication technologies. The relationship between strength and toughness of alloys is discussed in the context of maximizing both and avoiding the problem of dimensional and microstructural instability. All major classes of materials used in model construction are considered in some detail and in the Appendix selected numerical data is given for the most relevant materials. The stepped-specimen program to investigate stress-induced dimensional changes in alloys is discussed in detail together with interpretation of the initial results. The methods used to bond model components are considered with particular reference to the selection of filler alloys and temperature cycles to avoid microstructural degradation and loss of mechanical properties.

Social Cognitive Theory and Physical Activity Among Korean Male High-School Students.

PubMed

Lee, Chung Gun; Park, Seiyeong; Lee, Seung Hwan; Kim, Hyunwoo; Park, Ji-Won

2018-02-01

The most critical step in developing and implementing effective physical activity interventions is to understand the determinants and correlates of physical activity, and it is strongly suggested that such effort should be based on theories. The purpose of this study is to test the direct, indirect, and total effect of social cognitive theory constructs on physical activity among Korean male high-school students. Three-hundred and forty-one 10th-grade male students were recruited from a private single-sex high school located in Seoul, South Korea. Structural equation modeling was used to test the expected relationships among the latent variables. The proposed model accounted for 42% of the variance in physical activity. Self-efficacy had the strongest total effect on physical activity. Self-efficacy for being physically active was positively associated with physical activity ( p < .01). Self-efficacy also had positive indirect effects on physical activity through perceived benefits ( p < .05) and goal setting ( p < .01). The results of this study indicated that the social cognitive theory is a useful framework to understand physical activity among Korean male adolescents. Physical activity interventions targeting Korean male high-school students should focus on the major sources of efficacy.

Delving Deeper: Transforming Shapes Physically and Analytically

ERIC Educational Resources Information Center

Rathouz, Margaret; Novak, Christopher; Clifford, John

2013-01-01

Constructing formulas "from scratch" for calculating geometric measurements of shapes--for example, the area of a triangle--involves reasoning deductively and drawing connections between different methods (Usnick, Lamphere, and Bright 1992). Visual and manipulative models also play a role in helping students understand the underlying…

The formal de Rham complex

NASA Astrophysics Data System (ADS)

Zharinov, V. V.

2013-02-01

We propose a formal construction generalizing the classic de Rham complex to a wide class of models in mathematical physics and analysis. The presentation is divided into a sequence of definitions and elementary, easily verified statements; proofs are therefore given only in the key case. Linear operations are everywhere performed over a fixed number field {F} = {R},{C}. All linear spaces, algebras, and modules, although not stipulated explicitly, are by definition or by construction endowed with natural locally convex topologies, and their morphisms are continuous.

Nonlinear techniques for forecasting solar activity directly from its time series

NASA Technical Reports Server (NTRS)

Ashrafi, S.; Roszman, L.; Cooley, J.

1992-01-01

Numerical techniques for constructing nonlinear predictive models to forecast solar flux directly from its time series are presented. This approach makes it possible to extract dynamical invariants of our system without reference to any underlying solar physics. We consider the dynamical evolution of solar activity in a reconstructed phase space that captures the attractor (strange), given a procedure for constructing a predictor of future solar activity, and discuss extraction of dynamical invariants such as Lyapunov exponents and attractor dimension.

Nonlinear techniques for forecasting solar activity directly from its time series

NASA Technical Reports Server (NTRS)

Ashrafi, S.; Roszman, L.; Cooley, J.

1993-01-01

This paper presents numerical techniques for constructing nonlinear predictive models to forecast solar flux directly from its time series. This approach makes it possible to extract dynamical in variants of our system without reference to any underlying solar physics. We consider the dynamical evolution of solar activity in a reconstructed phase space that captures the attractor (strange), give a procedure for constructing a predictor of future solar activity, and discuss extraction of dynamical invariants such as Lyapunov exponents and attractor dimension.

Reduced order modeling of fluid/structure interaction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barone, Matthew Franklin; Kalashnikova, Irina; Segalman, Daniel Joseph

2009-11-01

This report describes work performed from October 2007 through September 2009 under the Sandia Laboratory Directed Research and Development project titled 'Reduced Order Modeling of Fluid/Structure Interaction.' This project addresses fundamental aspects of techniques for construction of predictive Reduced Order Models (ROMs). A ROM is defined as a model, derived from a sequence of high-fidelity simulations, that preserves the essential physics and predictive capability of the original simulations but at a much lower computational cost. Techniques are developed for construction of provably stable linear Galerkin projection ROMs for compressible fluid flow, including a method for enforcing boundary conditions that preservesmore » numerical stability. A convergence proof and error estimates are given for this class of ROM, and the method is demonstrated on a series of model problems. A reduced order method, based on the method of quadratic components, for solving the von Karman nonlinear plate equations is developed and tested. This method is applied to the problem of nonlinear limit cycle oscillations encountered when the plate interacts with an adjacent supersonic flow. A stability-preserving method for coupling the linear fluid ROM with the structural dynamics model for the elastic plate is constructed and tested. Methods for constructing efficient ROMs for nonlinear fluid equations are developed and tested on a one-dimensional convection-diffusion-reaction equation. These methods are combined with a symmetrization approach to construct a ROM technique for application to the compressible Navier-Stokes equations.« less

Development Scaffolding for Construction of Evaluation Instrument Training Program on The Cognitive Domain For Senior High School Physics Teachers and The Same Level

NASA Astrophysics Data System (ADS)

Arif, W.; Suhandi, A.; Kaniawati, I.; Setiawan, A.

2017-02-01

The development of scaffolding for evaluation instrument construction training program on the cognitive domain for senior high school physics teacher and the same level that is specified in the test instrument has been done. This development was motivated by the low ability of the majority of physics teachers in constructing the physics learning achievement test. This situation not in accordance with the demands of Permendiknas RI no. 16 tahun 2007 concerning the standard of academic qualifications and competence of teachers, stating that teachers should have a good ability to develop instruments for assessment and evaluation of process and learning outcomes. Based on the preliminary study results, it can be seen that the main cause of the inability of teachers in developing physics achievement test is because they do not good understand of the indicators for each aspect of cognitive domains. Scaffolding development is done by using the research and development methods formulated by Thiagarajan which includes define, design and develope steps. Develop step includes build the scaffolding, validation of scaffolding by experts and the limited pilot implementations on the training activities. From the build scaffolding step, resulted the scaffolding for the construction of test instruments training program which include the process steps; description of indicators, operationalization of indicators, construction the itemsframework (items scenarios), construction the items stem, construction the items and checking the items. The results of the validation by three validator indicates that the built scaffolding are suitable for use in the construction of physics achievement test training program, especially for novice. The limited pilot implementation of the built scaffolding conducted in training activities attended by 10 senior high school physics teachers in Garut district. The results of the limited pilot implementation shows that the built scaffolding have a medium effectiveness in improving the ability of senior high school physics teachers in constructing the physic achievement test instrument that is characterized by more than 70% of trainees achieve scores of test instruments construction of about 80 or more.

Review of pore network modelling of porous media: Experimental characterisations, network constructions and applications to reactive transport.

PubMed

Xiong, Qingrong; Baychev, Todor G; Jivkov, Andrey P

2016-09-01

Pore network models have been applied widely for simulating a variety of different physical and chemical processes, including phase exchange, non-Newtonian displacement, non-Darcy flow, reactive transport and thermodynamically consistent oil layers. The realism of such modelling, i.e. the credibility of their predictions, depends to a large extent on the quality of the correspondence between the pore space of a given medium and the pore network constructed as its representation. The main experimental techniques for pore space characterisation, including direct imaging, mercury intrusion porosimetry and gas adsorption, are firstly summarised. A review of the main pore network construction techniques is then presented. Particular focus is given on how such constructions are adapted to the data from experimentally characterised pore systems. Current applications of pore network models are considered, with special emphasis on the effects of adsorption, dissolution and precipitation, as well as biomass growth, on transport coefficients. Pore network models are found to be a valuable tool for understanding and predicting meso-scale phenomena, linking single pore processes, where other techniques are more accurate, and the homogenised continuum porous media, used by engineering community. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Semiparametric modeling: Correcting low-dimensional model error in parametric models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berry, Tyrus, E-mail: thb11@psu.edu; Harlim, John, E-mail: jharlim@psu.edu; Department of Meteorology, the Pennsylvania State University, 503 Walker Building, University Park, PA 16802-5013

2016-03-01

In this paper, a semiparametric modeling approach is introduced as a paradigm for addressing model error arising from unresolved physical phenomena. Our approach compensates for model error by learning an auxiliary dynamical model for the unknown parameters. Practically, the proposed approach consists of the following steps. Given a physics-based model and a noisy data set of historical observations, a Bayesian filtering algorithm is used to extract a time-series of the parameter values. Subsequently, the diffusion forecast algorithm is applied to the retrieved time-series in order to construct the auxiliary model for the time evolving parameters. The semiparametric forecasting algorithm consistsmore » of integrating the existing physics-based model with an ensemble of parameters sampled from the probability density function of the diffusion forecast. To specify initial conditions for the diffusion forecast, a Bayesian semiparametric filtering method that extends the Kalman-based filtering framework is introduced. In difficult test examples, which introduce chaotically and stochastically evolving hidden parameters into the Lorenz-96 model, we show that our approach can effectively compensate for model error, with forecasting skill comparable to that of the perfect model.« less

Statistical Analysis of Physiological Signals

NASA Astrophysics Data System (ADS)

Ruiz, María G.; Pérez, Leticia

2003-07-01

In spite of two hundred years of clinical practice, Homeopathy still lacks of scientific basis. Its fundamental laws, similia principle and the activity of the denominated ultra-high dilutions are controversial issues that do not fit into the mainstream medicine or current physical-chemistry field as well. Aside its clinical efficacy, the identification of physical - chemistry parameters, as markers of the homeopathic effect, would allow to construct mathematic models [1], which in turn, could provide clues regarding the involved mechanism.

Evapotranspiration versus oxygen intrusion: which is the main force in alleviating bioclogging of vertical-flow constructed wetlands during a resting operation?

PubMed

Hua, Guofen; Chen, Qiuwen; Kong, Jun; Li, Man

2017-08-01

Clogging is the most significant challenge limiting the application of constructed wetlands. Application of a forced resting period is a practical way to relieve clogging, particularly bioclogging. To reveal the alleviation mechanisms behind such a resting operation, evapotranspiration and oxygen flux were studied during a resting period in a laboratory vertical-flow constructed wetland model through physical simulation and numerical model analysis. In addition, the optimum theoretical resting duration was determined based on the time required for oxygen to completely fill the pores, i.e., formation of a sufficiently thick and completely dry layer. The results indicated that (1) evapotranspiration was not the key factor, but was a driving force in the alleviation of bioclogging; (2) the rate of oxygen diffusion into the pores was sufficient to oxidize and disperse the flocculant biofilm, which was essential to alleviate bioclogging. This study provides important insights into understanding how clogging/bioclogging can be alleviated in vertical-flow constructed wetlands. Graphical abstract Evapotranspiration versus oxygen intrusion in alleviating bioclogging in vertical flow constructed wetlands.

Validity of a scale of neighbourhood informal social control relevant to pre-schoolers' physical activity: A cross-sectional study.

PubMed

Cerin, Ester; Suen, Yi Nam; Barnett, Anthony; Huang, Wendy Y J; Mellecker, Robin R

2017-12-01

Childhood physical activity (PA) is important for health across the lifespan. Time pre-schoolers spend outdoors, which has been associated with more PA, is likely influenced by parents' perception of neighbourhood informal social control relevant to pre-schoolers' PA, defined as the willingness of neighbours to intervene to ensure social order and a safe community environment for young children's active play. To advance measurement of this construct, we assessed factorial and construct validities of the PA-related neighbourhood informal social control scale for parents of pre-schoolers (PANISC-PP). In 2013-2014, Hong Kong primary caregivers (n=394) of 3-5 year-old children completed a socio-demographic questionnaire, the preliminary version of the PANISC-PP, and self-report measures of theoretical neighbourhood correlates of PA-related neighbourhood informal social control (perceived signs of physical and social disorder, community cohesion, perceived stranger danger, risk of unintentional injury and traffic safety). The fit of the data to an a priori measurement model of the PANISC-PP was examined using confirmatory factor analyses. As the a priori model showed inadequate fit to the data, the factor structure was re-specified based on theoretical considerations. The final measurement models of the PANISC-PP showed acceptable fit to the data and consisted of three correlated latent factors: "General informal supervision", "Civic engagement for the creation of a better neighbourhood environment" and "Educating and assisting neighbourhood children". The internal reliability of the subscales was good (Cronbach's α values 0.82-0.89). Generalised additive mixed models indicated that all subscales were positively associated with community cohesion and scores on the subscale "Educating and assisting neighbourhood children" were related in the expected direction to all indicators of traffic and personal safety, supporting construct validity of the PANISC-PP. This study suggests that the PANISC-PP is a reliable and valid instrument for assessing parents' perceived neighbourhood informal social control related to pre-schoolers' PA.

Towards realistic singularity-free cosmological models

NASA Astrophysics Data System (ADS)

Senovilla, José M. M.

1996-02-01

We present an explicit general family of inhomogeneous cosmological models. The family contains an arbitrary function of comoving time (interpretable as the cosmological scale factor) and four arbitrary parameters. In general, it is a solution of Einstein's field equations for a fluid with anisotropic pressures, but it also includes a big subfamily of perfect-fluid metrics. The most interesting feature of this family is that it contains both all the diagonal separable singularity-free cosmological models recently found and all the Friedmann-Lemaître-Robertson-Walker standard models. This property allows one to speculate on the construction of some interesting models in which the Universe has been FLRW-like from some time on (for instance, since the nucleeosynthesis time), but it also went through primordial singularity-free inhomogeneous epochs (in fact, there are quite natural possibilities in which these primordial epochs are inflationary) without ever violating energy conditions or other physical properties. Nevertheless, the physical processes leading to the isotropization and homogenization of the Universe are not fixed nor indicated by the models themselves. The interesting properties of the general model are studied in some detail. ¢ 1996 The American Physical Society.

FAC: Flexible Atomic Code

NASA Astrophysics Data System (ADS)

Gu, Ming Feng

2018-02-01

FAC calculates various atomic radiative and collisional processes, including radiative transition rates, collisional excitation and ionization by electron impact, energy levels, photoionization, and autoionization, and their inverse processes radiative recombination and dielectronic capture. The package also includes a collisional radiative model to construct synthetic spectra for plasmas under different physical conditions.

Towards a Model of Talent Development in Physical Education

ERIC Educational Resources Information Center

Bailey, Richard; Morley, David

2006-01-01

Traditional conceptions of talent generally emphasise the construction of threshold values and the development of relatively unitary abilities, and this approach still dominates talent development programmes for elite sport. Most researchers on high ability, however, now favour domain-specific, multidimensional conceptions of ability that stress…

The calculation of theoretical chromospheric models and the interpretation of the solar spectrum

NASA Technical Reports Server (NTRS)

Avrett, Eugene H.

1994-01-01

Since the early 1970s we have been developing the extensive computer programs needed to construct models of the solar atmosphere and to calculate detailed spectra for use in the interpretation of solar observations. This research involves two major related efforts: work by Avrett and Loeser on the Pandora computer program for non-LTE modeling of the solar atmosphere including a wide range of physical processes, and work by Kurucz on the detailed synthesis of the solar spectrum based on opacity data for over 58 million atomic and molecular lines. Our goals are to determine models of the various features observed on the sun (sunspots, different components of quiet and active regions, and flares) by means of physically realistic models, and to calculate detailed spectra at all wavelengths that match observations of those features. These two goals are interrelated: discrepancies between calculated and observed spectra are used to determine improvements in the structure of the models, and in the detailed physical processes used in both the model calculations and the spectrum calculations. The atmospheric models obtained in this way provide not only the depth variation of various atmospheric parameters, but also a description of the internal physical processes that are responsible for nonradiative heating, and for solar activity in general.

The calculation of theoretical chromospheric models and the interpretation of solar spectra from rockets and spacecraft

NASA Technical Reports Server (NTRS)

Avrett, Eugene H.

1993-01-01

Since the early 1970s we have been developing the extensive computer programs needed to construct models of the solar atmosphere and to calculate detailed spectra for use in the interpretation of solar observations. This research involves two major related efforts: work by Avrett and Loeser on the Pandora computer program for non-LTE modeling of the solar atmosphere including a wide range of physical processes, and work by Kurucz on the detailed synthesis of the solar spectrum based on opacity data for over 58 million atomic and molecular lines. Our goals are to determine models of the various features observed on the Sun (sunspots, different components of quiet and active regions, and flares) by means of physically realistic models, and to calculate detailed spectra at all wavelengths that match observations of those features. These two goals are interrelated: discrepancies between calculated and observed spectra are used to determine improvements in the structure of the models, and in the detailed physical processes used in both the model calculations and the spectrum calculations. The atmospheric models obtained in this way provide not only the depth variation of various atmospheric parameters, but also a description of the internal physical processes that are responsible for non-radiative heating, and for solar activity in general.

Calabi-Yau structures on categories of matrix factorizations

NASA Astrophysics Data System (ADS)

Shklyarov, Dmytro

2017-09-01

Using tools of complex geometry, we construct explicit proper Calabi-Yau structures, that is, non-degenerate cyclic cocycles on differential graded categories of matrix factorizations of regular functions with isolated critical points. The formulas involve the Kapustin-Li trace and its higher corrections. From the physics perspective, our result yields explicit 'off-shell' models for categories of topological D-branes in B-twisted Landau-Ginzburg models.

From Desktop Toy to Educational Aid: Neo Magnets as an Alternative to Ball-and-Stick Models in Representing Carbon Fullerenes

ERIC Educational Resources Information Center

Kao, Jacqueline Y.; Yang, Min-Han; Lee, Chi-Young

2015-01-01

Neo magnets are neodymium magnet beads that have been marketed as a desktop toy. We proposed using neo magnets as an alternative building block to traditional ball-and-stick models to construct carbon allotropes, such as fullerene and various nanocone structures. Due to the lack of predetermined physical connections, the versatility of carbon…

How to make a good animation: A grounded cognition model of how visual representation design affects the construction of abstract physics knowledge

NASA Astrophysics Data System (ADS)

Chen, Zhongzhou; Gladding, Gary

2014-06-01

Visual representations play a critical role in teaching physics. However, since we do not have a satisfactory understanding of how visual perception impacts the construction of abstract knowledge, most visual representations used in instructions are either created based on existing conventions or designed according to the instructor's intuition, which leads to a significant variance in their effectiveness. In this paper we propose a cognitive mechanism based on grounded cognition, suggesting that visual perception affects understanding by activating "perceptual symbols": the basic cognitive unit used by the brain to construct a concept. A good visual representation activates perceptual symbols that are essential for the construction of the represented concept, whereas a bad representation does the opposite. As a proof of concept, we conducted a clinical experiment in which participants received three different versions of a multimedia tutorial teaching the integral expression of electric potential. The three versions were only different by the details of the visual representation design, only one of which contained perceptual features that activate perceptual symbols essential for constructing the idea of "accumulation." On a following post-test, participants receiving this version of tutorial significantly outperformed those who received the other two versions of tutorials designed to mimic conventional visual representations used in classrooms.

Antecedents and mediators of physical activity in endometrial cancer survivors: Increasing physical activity through Steps to Health

PubMed Central

Cox, Matthew; Carmack, Cindy; Hughes, Daniel; Baum, George; Brown, Jubilee; Jhingran, Anuja; Lu, Karen; Basen-Engquist, Karen

2015-01-01

OBJECTIVE Research shows that physical activity (PA) has a positive effect on cancer survivors including improving quality of life, improving physical fitness, and decreasing risk for cancer recurrence in some cancer types. Theory-based intervention approaches have identified self-efficacy as a potential mediator of PA interventions. This study examines the temporal relationships at four time points (T1–T4) between several social cognitive theory constructs and PA among a group of endometrial cancer survivors receiving a PA intervention. METHOD A sample of 98 sedentary women who were at least six months post treatment for endometrial cancer were given an intervention to increase their PA. The study tested whether modeling, physiological somatic sensations, and social support at previous time points predicted self-efficacy at later time points, which in turn predicted PA at later time points. RESULTS Results indicate that as physiological somatic sensations at T2 decrease, self-efficacy at T3 increases, which leads to an increase in PA at T4. This suggests that self-efficacy is a significant mediator between physiological somatic sensations and PA. Exploratory follow up models suggest model fit can be improved with the addition of contemporaneous effects between self-efficacy and PA at T3 and T4, changing the timing of the mediational relationships. CONCLUSIONS Physiological somatic sensations appear to be an important construct to target in order to increase PA in this population. While self-efficacy appeared to mediate the relationship between physiological somatic sensations and PA, the timing of this relationship is requires further study. PMID:25642840

Applicability of three-dimensional imaging techniques in fetal medicine*

PubMed Central

Werner Júnior, Heron; dos Santos, Jorge Lopes; Belmonte, Simone; Ribeiro, Gerson; Daltro, Pedro; Gasparetto, Emerson Leandro; Marchiori, Edson

2016-01-01

Objective To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. PMID:27818540

Brittle and ductile friction and the physics of tectonic tremor

USGS Publications Warehouse

Daub, Eric G.; Shelly, David R.; Guyer, Robert A.; Johnson, P.A.

2011-01-01

Observations of nonvolcanic tremor provide a unique window into the mechanisms of deformation and failure in the lower crust. At increasing depths, rock deformation gradually transitions from brittle, where earthquakes occur, to ductile, with tremor occurring in the transitional region. The physics of deformation in the transition region remain poorly constrained, limiting our basic understanding of tremor and its relation to earthquakes. We combine field and laboratory observations with a physical friction model comprised of brittle and ductile components, and use the model to provide constraints on the friction and stress state in the lower crust. A phase diagram is constructed that characterizes under what conditions all faulting behaviors occur, including earthquakes, tremor, silent transient slip, and steady sliding. Our results show that tremor occurs over a range of ductile and brittle frictional strengths, and advances our understanding of the physical conditions at which tremor and earthquakes take place.

Electron Induced Discharge Modeling, Testing, and Analysis for Scatha. Volume I. Phenomenology Study and Model Testing.

DTIC Science & Technology

1978-12-31

Dielectric Discharge. .. ......... 23 3.2.1 Total Emitted Charge .. ........... ........ 26 3.2.2 Emission Time History .. .. ................. 29 3.3...taken to be a rise time of 10 ns and a fall time of 10 to 100 ns. In addition, a physical model of the discharge mechanism has been developed in which...scale model of the P78-2, dubbed the SCATSAT was constructed whose design was chosen to simulate the basic structure of the real satellite, including the

An Easily Constructed and Versatile Molecular Model

NASA Astrophysics Data System (ADS)

Hernandez, Sandra A.; Rodriguez, Nora M.; Quinzani, Oscar

1996-08-01

Three-dimensional molecular models are powerful tools used in basic courses of general and organic chemistry when the students must visualize the spatial distributions of atoms in molecules and relate them to the physical and chemical properties of such molecules. This article discusses inexpensive, easily carried, and semipermanent molecular models that the students may build by themselves. These models are based upon two different types of arrays of thin flexible wires, like telephone hook-up wires, which may be bent easily but keep their shapes.

The design, analysis and experimental evaluation of an elastic model wing

NASA Technical Reports Server (NTRS)

Cavin, R. K., III; Thisayakorn, C.

1974-01-01

An elastic orbiter model was developed to evaluate the effectiveness of aeroelasticity computer programs. The elasticity properties were introduced by constructing beam-like straight wings for the wind tunnel model. A standard influence coefficient mathematical model was used to estimate aeroelastic effects analytically. In general good agreement was obtained between the empirical and analytical estimates of the deformed shape. However, in the static aeroelasticity case, it was found that the physical wing exhibited less bending and more twist than was predicted by theory.

Building information models for astronomy projects

NASA Astrophysics Data System (ADS)

Ariño, Javier; Murga, Gaizka; Campo, Ramón; Eletxigerra, Iñigo; Ampuero, Pedro

2012-09-01

A Building Information Model is a digital representation of physical and functional characteristics of a building. BIMs represent the geometrical characteristics of the Building, but also properties like bills of quantities, definition of COTS components, status of material in the different stages of the project, project economic data, etc. The BIM methodology, which is well established in the Architecture Engineering and Construction (AEC) domain for conventional buildings, has been brought one step forward in its application for Astronomical/Scientific facilities. In these facilities steel/concrete structures have high dynamic and seismic requirements, M&E installations are complex and there is a large amount of special equipment and mechanisms involved as a fundamental part of the facility. The detail design definition is typically implemented by different design teams in specialized design software packages. In order to allow the coordinated work of different engineering teams, the overall model, and its associated engineering database, is progressively integrated using a coordination and roaming software which can be used before starting construction phase for checking interferences, planning the construction sequence, studying maintenance operation, reporting to the project office, etc. This integrated design & construction approach will allow to efficiently plan construction sequence (4D). This is a powerful tool to study and analyze in detail alternative construction sequences and ideally coordinate the work of different construction teams. In addition engineering, construction and operational database can be linked to the virtual model (6D), what gives to the end users a invaluable tool for the lifecycle management, as all the facility information can be easily accessed, added or replaced. This paper presents the BIM methodology as implemented by IDOM with the E-ELT and ATST Enclosures as application examples.

Study on perception and control layer of mine CPS with mixed logic dynamic approach

NASA Astrophysics Data System (ADS)

Li, Jingzhao; Ren, Ping; Yang, Dayu

2017-01-01

Mine inclined roadway transportation system of mine cyber physical system is a hybrid system consisting of a continuous-time system and a discrete-time system, which can be divided into inclined roadway signal subsystem, error-proofing channel subsystems, anti-car subsystems, and frequency control subsystems. First, to ensure stable operation, improve efficiency and production safety, this hybrid system model with n inputs and m outputs is constructed and analyzed in detail, then its steady schedule state to be solved. Second, on the basis of the formal modeling for real-time systems, we use hybrid toolbox for system security verification. Third, the practical application of mine cyber physical system shows that the method for real-time simulation of mine cyber physical system is effective.

Cross-cultural adaptation and construct validity of the Korean version of a physical activity measure for community-dwelling elderly.

PubMed

Choi, Bongsam

2018-01-01

[Purpose] This study aimed to cross-cultural adapt and validate the Korean version of an physical activity measure (K-PAM) for community-dwelling elderly. [Subjects and Methods] One hundred and thirty eight community-dwelling elderlies, 32 males and 106 female, participated in the study. All participants were asked to fill out a fifty-one item questionnaire measuring perceived difficulty in the activities of daily living (ADL) for the elderly. One-parameter model of item response theory (Rasch analysis) was applied to determine the construct validity and to inspect item-level psychometric properties of 51 ADL items of the K-PAM. [Results] Person separation reliability (analogous to Cronbach's alpha) for internal consistency was ranging 0.93 to 0.94. A total of 16 items was misfit to the Rasch model. After misfit item deletion, 35 ADL items of the K-PAM were placed in an empirically meaningful hierarchy from easy to hard. The item-person map analysis delineated that the item difficulty was well matched for the elderlies with moderate and low ability except for high ceilings. [Conclusion] Cross-cultural adapted K-PAM was shown to be sufficient for establishing construct validity and stable psychometric properties confirmed by person separation reliability and fit statistics.

Physical activity and fatigue in breast cancer survivors: a panel model examining the role of self-efficacy and depression.

PubMed

Phillips, Siobhan M; McAuley, Edward

2013-05-01

Physical activity is associated with reductions in fatigue in breast cancer survivors. However, mechanisms underlying this relationship are not well-understood. The purpose of this study was to longitudinally test a model examining the role of self-efficacy and depression as potential mediators of the relationship between physical activity and fatigue in a sample of breast cancer survivors using both self-report and objective measures of physical activity. All participants (N = 1,527) completed self-report measures of physical activity, self-efficacy, depression, and fatigue at baseline and 6 months. A subsample was randomly selected to wear an accelerometer at both time points. It was hypothesized that physical activity indirectly influences fatigue via self-efficacy and depression. Relationships among model constructs were examined over the 6-month period using panel analysis within a covariance modeling framework. The hypothesized model provided a good model-data fit (χ(2) = 599.66, df = 105, P ≤ 0.001; CFI = 0.96; SRMR = 0.02) in the full sample when controlling for covariates. At baseline, physical activity indirectly influenced fatigue via self-efficacy and depression. These relationships were also supported across time. In addition, the majority of the hypothesized relationships were supported in the subsample with accelerometer data (χ(2) = 387.48, df = 147, P ≤ 0.001, CFI = 0.94, SRMR = 0.04). This study provides evidence to suggest the relationship between physical activity and fatigue in breast cancer survivors may be mediated by more proximal, modifiable outcomes of physical activity participation. Recommendations are made relative to future applications and research concerning these relationships.

Examining the Crossover from the Hadronic to Partonic Phase in QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Mingmei; Yu Meiling; Liu Lianshou

2008-03-07

A mechanism, consistent with color confinement, for the transition between perturbative and physical vacua during the gradual crossover from the hadronic to partonic phase is proposed. The essence of this mechanism is the appearance and growing up of a kind of grape-shape perturbative vacuum inside the physical one. A percolation model based on simple dynamics for parton delocalization is constructed to exhibit this mechanism. The crossover from hadronic matter to sQGP (strongly coupled quark-gluon plasma) as well as the transition from sQGP to weakly coupled quark-gluon plasma with increasing temperature is successfully described by using this model.

Stochastic Modeling and Generation of Partially Polarized or Partially Coherent Electromagnetic Waves

NASA Technical Reports Server (NTRS)

Davis, Brynmor; Kim, Edward; Piepmeier, Jeffrey; Hildebrand, Peter H. (Technical Monitor)

2001-01-01

Many new Earth remote-sensing instruments are embracing both the advantages and added complexity that result from interferometric or fully polarimetric operation. To increase instrument understanding and functionality a model of the signals these instruments measure is presented. A stochastic model is used as it recognizes the non-deterministic nature of any real-world measurements while also providing a tractable mathematical framework. A stationary, Gaussian-distributed model structure is proposed. Temporal and spectral correlation measures provide a statistical description of the physical properties of coherence and polarization-state. From this relationship the model is mathematically defined. The model is shown to be unique for any set of physical parameters. A method of realizing the model (necessary for applications such as synthetic calibration-signal generation) is given and computer simulation results are presented. The signals are constructed using the output of a multi-input multi-output linear filter system, driven with white noise.

Prototyping of cerebral vasculature physical models

PubMed Central

Khan, Imad S.; Kelly, Patrick D.; Singer, Robert J.

2014-01-01

Background: Prototyping of cerebral vasculature models through stereolithographic methods have the ability to accurately depict the 3D structures of complicated aneurysms with high accuracy. We describe the method to manufacture such a model and review some of its uses in the context of treatment planning, research, and surgical training. Methods: We prospectively used the data from the rotational angiography of a 40-year-old female who presented with an unruptured right paraclinoid aneurysm. The 3D virtual model was then converted to a physical life-sized model. Results: The model constructed was shown to be a very accurate depiction of the aneurysm and its associated vasculature. It was found to be useful, among other things, for surgical training and as a patient education tool. Conclusion: With improving and more widespread printing options, these models have the potential to become an important part of research and training modalities. PMID:24678427

Innovative learning model for improving students’ argumentation skill and concept understanding on science

NASA Astrophysics Data System (ADS)

Nafsiati Astuti, Rini

2018-04-01

Argumentation skill is the ability to compose and maintain arguments consisting of claims, supports for evidence, and strengthened-reasons. Argumentation is an important skill student needs to face the challenges of globalization in the 21st century. It is not an ability that can be developed by itself along with the physical development of human, but it must be developed under nerve like process, giving stimulus so as to require a person to be able to argue. Therefore, teachers should develop students’ skill of arguing in science learning in the classroom. The purpose of this study is to obtain an innovative learning model that are valid in terms of content and construct in improving the skills of argumentation and concept understanding of junior high school students. The assessment of content validity and construct validity was done through Focus Group Discussion (FGD), using the content and construct validation sheet, book model, learning video, and a set of learning aids for one meeting. Assessment results from 3 (three) experts showed that the learning model developed in the category was valid. The validity itself shows that the developed learning model has met the content requirement, the student needs, state of the art, strong theoretical and empirical foundation and construct validity, which has a connection of syntax stages and components of learning model so that it can be applied in the classroom activities

Exactly soluble local bosonic cocycle models, statistical transmutation, and simplest time-reversal symmetric topological orders in 3+1 dimensions

NASA Astrophysics Data System (ADS)

Wen, Xiao-Gang

2017-05-01

We propose a generic construction of exactly soluble local bosonic models that realize various topological orders with gappable boundaries. In particular, we construct an exactly soluble bosonic model that realizes a (3+1)-dimensional [(3+1)D] Z2-gauge theory with emergent fermionic Kramers doublet. We show that the emergence of such a fermion will cause the nucleation of certain topological excitations in space-time without pin+ structure. The exactly soluble model also leads to a statistical transmutation in (3+1)D. In addition, we construct exactly soluble bosonic models that realize 2 types of time-reversal symmetry-enriched Z2 topological orders in 2+1 dimensions, and 20 types of simplest time-reversal symmetry-enriched topological (SET) orders which have only one nontrivial pointlike and stringlike topological excitation. Many physical properties of those topological states are calculated using the exactly soluble models. We find that some time-reversal SET orders have pointlike excitations that carry Kramers doublet, a fractionalized time-reversal symmetry. We also find that some Z2 SET orders have stringlike excitations that carry anomalous (nononsite) Z2 symmetry, which can be viewed as a fractionalization of Z2 symmetry on strings. Our construction is based on cochains and cocycles in algebraic topology, which is very versatile. In principle, it can also realize emergent topological field theory beyond the twisted gauge theory.

Validation of the TTM processes of change measure for physical activity in an adult French sample.

PubMed

Bernard, Paquito; Romain, Ahmed-Jérôme; Trouillet, Raphael; Gernigon, Christophe; Nigg, Claudio; Ninot, Gregory

2014-04-01

Processes of change (POC) are constructs from the transtheoretical model that propose to examine how people engage in a behavior. However, there is no consensus about a leading model explaining POC and there is no validated French POC scale in physical activity This study aimed to compare the different existing models to validate a French POC scale. Three studies, with 748 subjects included, were carried out to translate the items and evaluate their clarity (study 1, n = 77), to assess the factorial validity (n = 200) and invariance/equivalence (study 2, n = 471), and to analyze the concurrent validity by stage × process analyses (study 3, n = 671). Two models displayed adequate fit to the data; however, based on the Akaike information criterion, the fully correlated five-factor model appeared as the most appropriate to measure POC in physical activity. The invariance/equivalence was also confirmed across genders and student status. Four of the five existing factors discriminated pre-action and post-action stages. These data support the validation of the POC questionnaire in physical activity among a French sample. More research is needed to explore the longitudinal properties of this scale.

Relationships among exercise beliefs, physical exercise, and subjective well-being: Evidence from Korean middle-aged adults.

PubMed

You, Sukkyung; Shin, Kyulee

2017-12-01

Physically active leisure plays a key role in successful aging. Exercise beliefs are one of the key predictors of exercise behavior. We used structural equation modeling to assess the plausibility of a conceptual model specifying hypothesized linkages among middle-aged adults' perceptions of (a) exercise beliefs, (b) physical exercise behavior, and (c) subjective well-being. Four hundred two adults in South Korea responded to survey questions designed to capture the above constructs. We found that physically active leisure participation leads to subjective well-being for both middle-aged men and women. However, men and women exercised for different reasons. Women exercised for the sake of their physical appearance and mental and emotional functioning, whereas men exercised for the sake of their social desirability and vulnerability to disease and aging. Based on our results, we suggest that men tend to show higher social face sensitivity, while women show more appearance management behavior. Based on these findings, we discussed the implications and future research directions.

Visual-spatial cognition in children using aided communication.

PubMed

Stadskleiv, Kristine; Batorowicz, Beata; Massaro, Munique; van Balkom, Hans; von Tetzchner, Stephen

2018-03-01

Children with severe motor impairments are restricted in their manipulation and exploration of objects, but little is known about how such limitations influence cognitive development. This study investigated visual-constructional abilities in 75 children and adolescents, aged 5;0-15;11 (years;months), with severe speech impairments and no intellectual disabilities (aided group) and in 56 children and adolescents with typical development (reference group). Verbal comprehension, non-verbal reasoning, and visual-spatial perception were assessed with standardized tests. The task of the participants was to verbally instruct communication partners to make physical constructions identical to models that the partner could not see. In the aided group, 55.7% of the constructions were identical to the models participants described, compared to 91.3% in the reference group. In the aided group, test results explained 51.4% of the variance in construction errors. The results indicate that the participants' language skills were decisive for construction success. Visual-perceptual challenges were common among the aided communicators, and their instructions included little information about size and spatial relations. This may reflect less experience with object manipulation and construction than children with typical development, and using aided communication to instruct others to make three-dimensional constructions. The results imply a need for interventions that compensate for the lack of relevant experience.

Vacuum polarization of the quantized massive fields in Friedman-Robertson-Walker spacetime

NASA Astrophysics Data System (ADS)

Matyjasek, Jerzy; Sadurski, Paweł; Telecka, Małgorzata

2014-04-01

The stress-energy tensor of the quantized massive fields in a spatially open, flat, and closed Friedman-Robertson-Walker universe is constructed using the adiabatic regularization (for the scalar field) and the Schwinger-DeWitt approach (for the scalar, spinor, and vector fields). It is shown that the stress-energy tensor calculated in the sixth adiabatic order coincides with the result obtained from the regularized effective action, constructed from the heat kernel coefficient a3. The behavior of the tensor is examined in the power-law cosmological models, and the semiclassical Einstein field equations are solved exactly in a few physically interesting cases, such as the generalized Starobinsky models.

Study on induced radioactivity of China Spallation Neutron Source

NASA Astrophysics Data System (ADS)

Wu, Qing-Biao; Wang, Qing-Bin; Wu, Jing-Min; Ma, Zhong-Jian

2011-06-01

China Spallation Neutron Source (CSNS) is the first High Energy Intense Proton Accelerator planned to be constructed in China during the State Eleventh Five-Year Plan period, whose induced radioactivity is very important for occupational disease hazard assessment and environmental impact assessment. Adopting the FLUKA code, the authors have constructed a cylinder-tunnel geometric model and a line-source sampling physical model, deduced proper formulas to calculate air activation, and analyzed various issues with regard to the activation of different tunnel parts. The results show that the environmental impact resulting from induced activation is negligible, whereas the residual radiation in the tunnels has a great influence on maintenance personnel, so strict measures should be adopted.

Does level of specificity affect measures of motivation to comply? A randomized evaluation.

PubMed

Branscum, Paul; Senkowski, Valerie

2018-05-30

The theory of planned behavior (TPB) is a popular value-expectancy model in social and behavioral health. Motivation to comply, one of the theory's constructs, has not been well operationalized and measured in the past, and to date, there has been no assessment of whether level of specificity affects the measurement of the construct. The purpose of this study was to measure the motivation to comply construct across four domains (from general to TACT-behavior specific) and evaluate the potential impact the differences have when identifying determinants of generalized injunctive norms. Students (n = 234) attending a large southwestern university completed a TPB survey related to sleep and physical activity, and were randomized to one of four domains that measured motivation to comply (General domain, n = 58; Health domain, n = 60; Behavioral domain, n = 56; and TACT domain, n = 60). Across both behaviors, motivation to comply measurements did not appear to be affected by changing the level of specificity. Referents for sleep and physical activity were mostly significant, but the effects were small to medium. Future researchers should consider removing motivation to comply measures from TPB surveys to reduce respondent burden or find alternative ways of measuring the construct.

Allocation of State Funds for Construction and Renovation of Schools in Georgia.

ERIC Educational Resources Information Center

Walker, Mary Beth; Sjoquist, David L.

1996-01-01

Examines Georgia's model capital outlay program for public schools. Despite the current program's many positive aspects, incentives provided to local school districts can lead to inefficiencies, contradictions, and inequities for districts with older physical plants. The program also contains an incentive to use debt financing, rather than…

Multidimensional Measurement of Situational Interest in Physical Education: Application of Bifactor Exploratory Structural Equation Modeling

ERIC Educational Resources Information Center

Garn, Alex C.

2017-01-01

Multidimensional measurement is a common theme in motivation research because many constructs are conceptualized as having an overarching general factor (e.g., situational interest) and specific dimensions (e.g., attention demand, challenge, exploration intention, instant enjoyment, novelty). This review addresses current issues associated with…

The Design and Construction of a Simple Transmission Electron Microscope for Educational Purposes.

ERIC Educational Resources Information Center

Hearsey, Paul K.

This document presents a model for a simple transmission electron microscope for educational purposes. This microscope could demonstrate thermonic emission, particle acceleration, electron deflection, and flourescence. It is designed to be used in high school science courses, particularly physics, taking into account the size, weight, complexity…

Psychosocial Correlates of Dating Violence Victimization among Latino Youth

ERIC Educational Resources Information Center

Howard, Donna E.; Beck, Kenneth; Kerr, Melissa Hallmark; Shattuck, Teresa

2005-01-01

To examine the association between physical dating violence victimization and risk and protective factors, an anonymous, cross-sectional, self-reported survey was administered to Latino youth (n = 446) residing in suburban Washington, DC. Multivariate logistic regression models were constructed, and adjusted OR and 95% CI were examined.…

Physics-based subsurface visualization of human tissue.

PubMed

Sharp, Richard; Adams, Jacob; Machiraju, Raghu; Lee, Robert; Crane, Robert

2007-01-01

In this paper, we present a framework for simulating light transport in three-dimensional tissue with inhomogeneous scattering properties. Our approach employs a computational model to simulate light scattering in tissue through the finite element solution of the diffusion equation. Although our model handles both visible and nonvisible wavelengths, we especially focus on the interaction of near infrared (NIR) light with tissue. Since most human tissue is permeable to NIR light, tools to noninvasively image tumors, blood vasculature, and monitor blood oxygenation levels are being constructed. We apply this model to a numerical phantom to visually reproduce the images generated by these real-world tools. Therefore, in addition to enabling inverse design of detector instruments, our computational tools produce physically-accurate visualizations of subsurface structures.

Motivation for physical activity in children: a moving matter in need for study.

PubMed

Pannekoek, Linda; Piek, Jan P; Hagger, Martin S

2013-10-01

Motivation for physical activity in children below the age of 12 years is a largely underrepresented issue in contemporary research. Although engagement in sufficient physical activity is highly important for children's current and later health, relatively little is known of the factors that motivate children to be physically active. Various theories have been developed in an attempt to explain motivation toward physical activity in adults. Recent developments have focussed on integrating constructs of these theories in order to attain a comprehensive account of motivated behavior. The relationships between different motivational constructs have generally been investigated in healthy adolescents and adults. This manuscript outlines why more theoretically driven research into children's motivation toward physical activity is needed. Constructs stemming from various motivational theories and their interrelationship as evidenced in youth and adults will be summarized. The current state of research on the applicability of these motivational constructs to children, and the generalizability of the interrelationship between the constructs to child samples will be outlined. A deeper insight into the motivational determinants of physical activity participation in children could inform the design of interventions to facilitate the development of physically active lifestyles that persist at older ages. Copyright © 2013 Elsevier B.V. All rights reserved.

Physics Metacognition Inventory Part II: Confirmatory factor analysis and Rasch analysis

NASA Astrophysics Data System (ADS)

Taasoobshirazi, Gita; Bailey, MarLynn; Farley, John

2015-11-01

The Physics Metacognition Inventory was developed to measure physics students' metacognition for problem solving. In one of our earlier studies, an exploratory factor analysis provided evidence of preliminary construct validity, revealing six components of students' metacognition when solving physics problems including knowledge of cognition, planning, monitoring, evaluation, debugging, and information management. The college students' scores on the inventory were found to be reliable and related to students' physics motivation and physics grade. However, the results of the exploratory factor analysis indicated that the questionnaire could be revised to improve its construct validity. The goal of this study was to revise the questionnaire and establish its construct validity through a confirmatory factor analysis. In addition, a Rasch analysis was applied to the data to better understand the psychometric properties of the inventory and to further evaluate the construct validity. Results indicated that the final, revised inventory is a valid, reliable, and efficient tool for assessing student metacognition for physics problem solving.

Software For Design Of Life-Support Systems

NASA Technical Reports Server (NTRS)

Rudokas, Mary R.; Cantwell, Elizabeth R.; Robinson, Peter I.; Shenk, Timothy W.

1991-01-01

Design Assistant Workstation (DAWN) computer program is prototype of expert software system for analysis and design of regenerative, physical/chemical life-support systems that revitalize air, reclaim water, produce food, and treat waste. Incorporates both conventional software for quantitative mathematical modeling of physical, chemical, and biological processes and expert system offering user stored knowledge about materials and processes. Constructs task tree as it leads user through simulated process, offers alternatives, and indicates where alternative not feasible. Also enables user to jump from one design level to another.

Topics in elementary particle physics

NASA Astrophysics Data System (ADS)

Jin, Xiang

The author of this thesis discusses two topics in elementary particle physics: n-ary algebras and their applications to M-theory (Part I), and functional evolution and Renormalization Group flows (Part II). In part I, Lie algebra is extended to four different n-ary algebraic structure: generalized Lie algebra, Filippov algebra, Nambu algebra and Nambu-Poisson tensor; though there are still many other n-ary algebras. A natural property of Generalized Lie algebras — the Bremner identity, is studied, and proved with a totally different method from its original version. We extend Bremner identity to n-bracket cases, where n is an arbitrary odd integer. Filippov algebras do not focus on associativity, and are defined by the Fundamental identity. We add associativity to Filippov algebras, and give examples of how to construct Filippov algebras from su(2), bosonic oscillator, Virasoro algebra. We try to include fermionic charges into the ternary Virasoro-Witt algebra, but the attempt fails because fermionic charges keep generating new charges that make the algebra not closed. We also study the Bremner identity restriction on Nambu algebras and Nambu-Poisson tensors. So far, the only example 3-algebra being used in physics is the BLG model with 3-algebra A4, describing two M2-branes interactions. Its extension with Nambu algebra, BLG-NB model, is believed to describe infinite M2-branes condensation. Also, there is another propose for M2-brane interactions, the ABJM model, which is constructed by ordinary Lie algebra. We compare the symmetry properties between them, and discuss the possible approaches to include these three models into a grand unification theory. In Part II, we give an approximate solution for Schroeder's equations, based on series and conjugation methods. We use the logistic map as an example, and demonstrate that this approximate solution converges to known analytical solutions around the fixed point, around which the approximate solution is constructed. Although the closed-form solutions for Schroeder's equations can not always be approached analytically, by fitting the approximation solutions, one can still obtain closed-form solutions sometimes. Based on Schroeder's theory, approximate solutions for trajectories, velocities and potentials can also be constructed. The approximate solution is significantly useful to calculate the beta function in renormalization group trajectory. By "wrapping" the series solutions with the conjugations from different inverse functions, we generate different branches of the trajectory, and construct a counterexample for a folk theorem about limited cycles.

Point clouds in BIM

NASA Astrophysics Data System (ADS)

Antova, Gergana; Kunchev, Ivan; Mickrenska-Cherneva, Christina

2016-10-01

The representation of physical buildings in Building Information Models (BIM) has been a subject of research since four decades in the fields of Construction Informatics and GeoInformatics. The early digital representations of buildings mainly appeared as 3D drawings constructed by CAD software, and the 3D representation of the buildings was only geometric, while semantics and topology were out of modelling focus. On the other hand, less detailed building representations, with often focus on ‘outside’ representations were also found in form of 2D /2,5D GeoInformation models. Point clouds from 3D laser scanning data give a full and exact representation of the building geometry. The article presents different aspects and the benefits of using point clouds in BIM in the different stages of a lifecycle of a building.

Evaluating the Impacts of Health, Social Network and Capital on Craft Efficiency and Productivity: A Case Study of Construction Workers in China

PubMed Central

Yi, Wen; Miao, Mengyi; Zhang, Lei

2018-01-01

The construction industry has been recognized, for many years, as among those having a high likelihood of accidents, injuries and occupational illnesses. Such risks of construction workers can lead to low productivity and social problems. As a result, construction workers’ well-being should be highly addressed to improve construction workers’ efficiency and productivity. Meanwhile, the social support from a social network and capital (SNC) of construction workers has been considered as an effective approach to promote construction workers’ physical and mental health (P&M health), as well as their work efficiency and productivity. Based on a comprehensive literature review, a conceptual model, which aims to improve construction workers’ efficiency and productivity from the perspective of health and SNC, was proposed. A questionnaire survey was conducted to investigate the construction workers’ health, SNC and work efficiency and productivity in Nanjing, China. A structural equation model (SEM) was employed to test the three hypothetical relationships among construction workers’ P&M health, SNC and work efficiency and productivity. The results indicated that the direct impacts from construction workers’ P&M health on work efficiency and productivity were more significant than that from the SNC. In addition, the construction workers’ social capital and the network can indirectly influence the work efficiency and productivity by affecting the construction workers’ P&M health. Therefore, strategies for enhancing construction workers’ efficiency and productivity were proposed. Furthermore, many useable suggestions can be drawn from the research findings from the perspective of a government. The identified indicators and relationships would contribute to the construction work efficiency and productivity assessment and health management from the perspective of the construction workers. PMID:29462861

Evaluating the Impacts of Health, Social Network and Capital on Craft Efficiency and Productivity: A Case Study of Construction Workers in China.

PubMed

Yuan, Jingfeng; Yi, Wen; Miao, Mengyi; Zhang, Lei

2018-02-15

The construction industry has been recognized, for many years, as among those having a high likelihood of accidents, injuries and occupational illnesses. Such risks of construction workers can lead to low productivity and social problems. As a result, construction workers' well-being should be highly addressed to improve construction workers' efficiency and productivity. Meanwhile, the social support from a social network and capital (SNC) of construction workers has been considered as an effective approach to promote construction workers' physical and mental health (P&M health), as well as their work efficiency and productivity. Based on a comprehensive literature review, a conceptual model, which aims to improve construction workers' efficiency and productivity from the perspective of health and SNC, was proposed. A questionnaire survey was conducted to investigate the construction workers' health, SNC and work efficiency and productivity in Nanjing, China. A structural equation model (SEM) was employed to test the three hypothetical relationships among construction workers' P&M health, SNC and work efficiency and productivity. The results indicated that the direct impacts from construction workers' P&M health on work efficiency and productivity were more significant than that from the SNC. In addition, the construction workers' social capital and the network can indirectly influence the work efficiency and productivity by affecting the construction workers' P&M health. Therefore, strategies for enhancing construction workers' efficiency and productivity were proposed. Furthermore, many useable suggestions can be drawn from the research findings from the perspective of a government. The identified indicators and relationships would contribute to the construction work efficiency and productivity assessment and health management from the perspective of the construction workers.

Targeting Neuroblastoma Cell Surface Proteins: Recommendations for Homology Modeling of hNET, ALK, and TrkB.

PubMed

Haddad, Yazan; Heger, Zbyněk; Adam, Vojtech

2017-01-01

Targeted therapy is a promising approach for treatment of neuroblastoma as evident from the large number of targeting agents employed in clinical practice today. In the absence of known crystal structures, researchers rely on homology modeling to construct template-based theoretical structures for drug design and testing. Here, we discuss three candidate cell surface proteins that are suitable for homology modeling: human norepinephrine transporter (hNET), anaplastic lymphoma kinase (ALK), and neurotrophic tyrosine kinase receptor 2 (NTRK2 or TrkB). When choosing templates, both sequence identity and structure quality are important for homology modeling and pose the first of many challenges in the modeling process. Homology modeling of hNET can be improved using template models of dopamine and serotonin transporters instead of the leucine transporter (LeuT). The extracellular domains of ALK and TrkB are yet to be exploited by homology modeling. There are several idiosyncrasies that require direct attention throughout the process of model construction, evaluation and refinement. Shifts/gaps in the alignment between the template and target, backbone outliers and side-chain rotamer outliers are among the main sources of physical errors in the structures. Low-conserved regions can be refined with loop modeling method. Residue hydrophobicity, accessibility to bound metals or glycosylation can aid in model refinement. We recommend resolving these idiosyncrasies as part of "good modeling practice" to obtain highest quality model. Decreasing physical errors in protein structures plays major role in the development of targeting agents and understanding of chemical interactions at the molecular level.

Psychometric properties of the PROMIS Physical Function item bank in patients receiving physical therapy.

PubMed

Crins, Martine H P; van der Wees, Philip J; Klausch, Thomas; van Dulmen, Simone A; Roorda, Leo D; Terwee, Caroline B

2018-01-01

The Patient-Reported Outcomes Measurement Information System (PROMIS) is a universally applicable set of instruments, including item banks, short forms and computer adaptive tests (CATs), measuring patient-reported health across different patient populations. PROMIS CATs are highly efficient and the use in practice is considered feasible with little administration time, offering standardized and routine patient monitoring. Before an item bank can be used as CAT, the psychometric properties of the item bank have to be examined. Therefore, the objective was to assess the psychometric properties of the Dutch-Flemish PROMIS Physical Function item bank (DF-PROMIS-PF) in Dutch patients receiving physical therapy. Cross-sectional study. 805 patients >18 years, who received any kind of physical therapy in primary care in the past year, completed the full DF-PROMIS-PF (121 items). Unidimensionality was examined by Confirmatory Factor Analysis and local dependence and monotonicity were evaluated. A Graded Response Model was fitted. Construct validity was examined with correlations between DF-PROMIS-PF T-scores and scores on two legacy instruments (SF-36 Health Survey Physical Functioning scale [SF36-PF10] and the Health Assessment Questionnaire Disability-Index [HAQ-DI]). Reliability (standard errors of theta) was assessed. The results for unidimensionality were mixed (scaled CFI = 0.924, TLI = 0.923, RMSEA = 0.045, 1th factor explained 61.5% of variance). Some local dependence was found (8.2% of item pairs). The item bank showed a broad coverage of the physical function construct (threshold-parameters range: -4.28-2.33) and good construct validity (correlation with SF36-PF10 = 0.84 and HAQ-DI = -0.85). Furthermore, the DF-PROMIS-PF showed greater reliability over a broader score-range than the SF36-PF10 and HAQ-DI. The psychometric properties of the DF-PROMIS-PF item bank are sufficient. The DF-PROMIS-PF can now be used as short forms or CAT to measure the level of physical function of physiotherapy patients.

Design of exchange-correlation functionals through the correlation factor approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlíková Přecechtělová, Jana, E-mail: j.precechtelova@gmail.com, E-mail: Matthias.Ernzerhof@UMontreal.ca; Institut für Chemie, Theoretische Chemie / Quantenchemie, Sekr. C7, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin; Bahmann, Hilke

The correlation factor model is developed in which the spherically averaged exchange-correlation hole of Kohn-Sham theory is factorized into an exchange hole model and a correlation factor. The exchange hole model reproduces the exact exchange energy per particle. The correlation factor is constructed in such a manner that the exchange-correlation energy correctly reduces to exact exchange in the high density and rapidly varying limits. Four different correlation factor models are presented which satisfy varying sets of physical constraints. Three models are free from empirical adjustments to experimental data, while one correlation factor model draws on one empirical parameter. The correlationmore » factor models are derived in detail and the resulting exchange-correlation holes are analyzed. Furthermore, the exchange-correlation energies obtained from the correlation factor models are employed to calculate total energies, atomization energies, and barrier heights. It is shown that accurate, non-empirical functionals can be constructed building on exact exchange. Avenues for further improvements are outlined as well.« less

Constructing exact perturbations of the standard cosmological models

NASA Astrophysics Data System (ADS)

Sopuerta, Carlos F.

1999-11-01

In this paper we show a procedure to construct cosmological models which, according to a covariant criterion, can be seen as exact (nonlinear) perturbations of the standard Friedmann-Lemaı⁁tre-Robertson-Walker (FLRW) cosmological models. The special properties of this procedure will allow us to select some of the characteristics of the models and also to study in depth their main geometrical and physical features. In particular, the models are conformally stationary, which means that they are compatible with the existence of isotropic radiation, and the observers that would measure this isotropy are rotating. Moreover, these models have two arbitrary functions (one of them is a complex function) which control their main properties, and in general they do not have any isometry. We study two examples, focusing on the case when the underlying FLRW models are flat dust models. In these examples we compare our results with those of the linearized theory of perturbations about a FLRW background.

Predictive Factors of Regular Physical Activity among Middle-Aged Women in the West of Iran, Hamadan: Application of PRECEDE Model.

PubMed

Emdadi, Shohreh; Hazavehie, Seyed Mohammad Mehdi; Soltanian, Alireza; Bashirian, Saeed; Heidari Moghadam, Rashid

2015-01-01

Regular physical activity is important for midlife women. Models and theories help better understanding this behavior among middle-aged women and better planning for change behavior in target group. This study aimed to investigate predictive factors of regular physical activity among middle-aged women based on PRECEDE model as a theoretical framework. This descriptive-analytical study was performed on 866 middle-aged women of Hamadan City western Iran, recruited with a proportional stratified sampling method in 2015. The participants completed a self-administered questionnaire including questions on demographic characteristics and PRECEDE model constructs and IPAQ questionnaire. Data were then analyzed by SPSS-16 and AMOS-16 using the Pearson correlation test and the pathway analysis method. Overall, 57% of middle-aged women were inactive (light level) or not sufficiently active. With SEM (Structural Equation Modeling) analysis, knowledge b=0.84, P<0.001, attitude b=0.799, P<0.001, self-efficacy b=0.633, P<0.001 as predisposing factor and social support as reinforcing factor b=0.2, P<0.001 were the most important predictors for physical activity among middle-aged women in Hamadan. The framework of the PRECEDE model is useful in understanding regular physical activity among middle-aged women. Furthermore, results showed the importance of predisposing and reinforcing factors when planning educational interventions.

Structural equation modelling of lower back pain due to whole-body vibration exposure in the construction industry.

PubMed

Vitharana, Vitharanage Hashini Paramitha; Chinda, Thanwadee

2017-09-21

Whole-body vibration (WBV) exposure is a health hazard among workers, causing lower back pain (LBP) in the construction industry. This study examines key factors affecting LBP due to WBV exposure using exploratory factor analysis and structural equation modelling. The results confirm five key factors (equipment, job related, organizational, personal, social context) with their 17 associated items. The organizational factor is found the most important, as it influences the other four factors. The results also show that appropriate seat type, specific training programme, job rotation, workers' satisfaction and workers' physical condition are crucial in reducing LBP due to WBV exposure. Moreover, provision of new machines without proper training and good working condition might not help reduce LBP due to WBV exposure. The results help the construction companies to better understand key factors affecting LBP due to WBV exposure, and to plan for a better health improvement programme.

Multi-scale modeling of tsunami flows and tsunami-induced forces

NASA Astrophysics Data System (ADS)

Qin, X.; Motley, M. R.; LeVeque, R. J.; Gonzalez, F. I.

2016-12-01

The modeling of tsunami flows and tsunami-induced forces in coastal communities with the incorporation of the constructed environment is challenging for many numerical modelers because of the scale and complexity of the physical problem. A two-dimensional (2D) depth-averaged model can be efficient for modeling of waves offshore but may not be accurate enough to predict the complex flow with transient variance in vertical direction around constructed environments on land. On the other hand, using a more complex three-dimensional model is much more computational expensive and can become impractical due to the size of the problem and the meshing requirements near the built environment. In this study, a 2D depth-integrated model and a 3D Reynolds Averaged Navier-Stokes (RANS) model are built to model a 1:50 model-scale, idealized community, representative of Seaside, OR, USA, for which existing experimental data is available for comparison. Numerical results from the two numerical models are compared with each other as well as experimental measurement. Both models predict the flow parameters (water level, velocity, and momentum flux in the vicinity of the buildings) accurately, in general, except for time period near the initial impact, where the depth-averaged models can fail to capture the complexities in the flow. Forces predicted using direct integration of predicted pressure on structural surfaces from the 3D model and using momentum flux from the 2D model with constructed environment are compared, which indicates that force prediction from the 2D model is not always reliable in such a complicated case. Force predictions from integration of the pressure are also compared with forces predicted from bare earth momentum flux calculations to reveal the importance of incorporating the constructed environment in force prediction models.

Didactical Reconstruction of Processes in Knowledge Construction: Pre-Service Physics Teachers Learning the Law of Electromagnetic Induction

ERIC Educational Resources Information Center

Mantyla, Terhi

2012-01-01

In physics teacher education, two central goals are first to learn the structures of physics knowledge, and second the processes of its construction. To know the structure is to know the framework of concepts and laws; to know the processes is to know where the knowledge comes from, how the framework is constructed, and how it can be justified.…

Unfolding an electronic integrate-and-fire circuit.

PubMed

Carrillo, Humberto; Hoppensteadt, Frank

2010-01-01

Many physical and biological phenomena involve accumulation and discharge processes that can occur on significantly different time scales. Models of these processes have contributed to understand excitability self-sustained oscillations and synchronization in arrays of oscillators. Integrate-and-fire (I+F) models are popular minimal fill-and-flush mathematical models. They are used in neuroscience to study spiking and phase locking in single neuron membranes, large scale neural networks, and in a variety of applications in physics and electrical engineering. We show here how the classical first-order I+F model fits into the theory of nonlinear oscillators of van der Pol type by demonstrating that a particular second-order oscillator having small parameters converges in a singular perturbation limit to the I+F model. In this sense, our study provides a novel unfolding of such models and it identifies a constructible electronic circuit that is closely related to I+F.

Hybrid network modeling and the effect of image resolution on digitally-obtained petrophysical and two-phase flow properties

NASA Astrophysics Data System (ADS)

Aghaei, A.

2017-12-01

Digital imaging and modeling of rocks and subsequent simulation of physical phenomena in digitally-constructed rock models are becoming an integral part of core analysis workflows. One of the inherent limitations of image-based analysis, at any given scale, is image resolution. This limitation becomes more evident when the rock has multiple scales of porosity such as in carbonates and tight sandstones. Multi-scale imaging and constructions of hybrid models that encompass images acquired at multiple scales and resolutions are proposed as a solution to this problem. In this study, we investigate the effect of image resolution and unresolved porosity on petrophysical and two-phase flow properties calculated based on images. A helical X-ray micro-CT scanner with a high cone-angle is used to acquire digital rock images that are free of geometric distortion. To remove subjectivity from the analyses, a semi-automated image processing technique is used to process and segment the acquired data into multiple phases. Direct and pore network based models are used to simulate physical phenomena and obtain absolute permeability, formation factor and two-phase flow properties such as relative permeability and capillary pressure. The effect of image resolution on each property is investigated. Finally a hybrid network model incorporating images at multiple resolutions is built and used for simulations. The results from the hybrid model are compared against results from the model built at the highest resolution and those from laboratory tests.

Social influences on physical activity in Anglo- and Vietnamese-Australian adolescent males in a single sex school.

PubMed

Wilson, Andrew N; Dollman, James

2007-06-01

Understanding factors that influence physical activity levels of adolescents can assist the design of more effective interventions. Social support is a consistent correlate of youth physical activity but few studies have examined this in different cultural settings. Male adolescents (n=180, age=13.58+/-0.97 years) from a metropolitan single sex private school participated in this study. Habitual physical activity was estimated using the 3-day physical activity recall (3dPAR), and aspects of social support to be physically active using a specifically designed questionnaire. Comparisons were made between Anglo-Australians (n=118), whose parents were both born in Australia, and Vietnamese-Australians (n=62), whose parents were both born in Vietnam. There was a trend towards higher physical activity among Anglo-Australians, particularly on weekends. Anglo-Australians reported significantly more parental and peer support across most items pertaining to these constructs. Among the whole sample, social support variables explained 5-12% of the total explained variance in physical activity, with items pertaining to father and best friend support emerging as the strongest and most consistent predictors in multiple regression models. Among Anglo-Australians, the prediction models were relatively weak, explaining 0-9% of the total explained variance in physical activity. Prediction models for physical activity among Vietnamese-Australians were much stronger, explaining 11-32% of the total explained variance, with father's support variables contributing consistently to these models. The strong paternal influence on physical activity among Vietnamese-Australians needs to be confirmed in more diverse population groups, but results from this study suggest that interventions promoting physical activity among adolescent boys need to take into account cultural background as a moderator of widely reported social influences.

Physical modeling with orthotropic material based on harmonic fields.

PubMed

Liao, Sheng-Hui; Zou, Bei-Ji; Geng, Jian-Ping; Wang, Jin-Xiao; Ding, Xi

2012-11-01

Although it is well known that human bone tissues have obvious orthotropic material properties, most works in the physical modeling field adopted oversimplified isotropic or approximated transversely isotropic elasticity due to the simplicity. This paper presents a convenient methodology based on harmonic fields, to construct volumetric finite element mesh integrated with complete orthotropic material. The basic idea is taking advantage of the fact that the longitudinal axis direction indicated by the shape configuration of most bone tissues is compatible with the trajectory of the maximum material stiffness. First, surface harmonic fields of the longitudinal axis direction for individual bone models were generated, whose scalar distribution pattern tends to conform very well to the object shape. The scalar iso-contours were extracted and sampled adaptively to construct volumetric meshes of high quality. Following, the surface harmonic fields were expanded over the whole volumetric domain to create longitudinal and radial volumetric harmonic fields, from which the gradient vector fields were calculated and employed as the orthotropic principal axes vector fields. Contrastive finite element analyses demonstrated that elastic orthotropy has significant effect on simulating stresses and strains, including the value as well as distribution pattern, which underlines the relevance of our orthotropic modeling scheme. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A Worksheet to Enhance Students’ Conceptual Understanding in Vector Components

NASA Astrophysics Data System (ADS)

Wutchana, Umporn; Emarat, Narumon

2017-09-01

With and without physical context, we explored 59 undergraduate students’conceptual and procedural understanding of vector components using both open ended problems and multiple choice items designed based on research instruments used in physics education research. The results showed that a number of students produce errors and revealed alternative conceptions especially when asked to draw graphical form of vector components. It indicated that most of them did not develop a strong foundation of understanding in vector components and could not apply those concepts to such problems with physical context. Based on the findings, we designed a worksheet to enhance the students’ conceptual understanding in vector components. The worksheet is composed of three parts which help students to construct their own understanding of definition, graphical form, and magnitude of vector components. To validate the worksheet, focus group discussions of 3 and 10 graduate students (science in-service teachers) had been conducted. The modified worksheet was then distributed to 41 grade 9 students in a science class. The students spent approximately 50 minutes to complete the worksheet. They sketched and measured vectors and its components and compared with the trigonometry ratio to condense the concepts of vector components. After completing the worksheet, their conceptual model had been verified. 83% of them constructed the correct model of vector components.

Theoretical modeling of indoor radon concentration and its validation through measurements in South-East Haryana, India.

PubMed

Singh, Prabhjot; Sahoo, B K; Bajwa, B S

2016-04-15

A three dimensional semi-empirical model deduced from the existing 1-D model has been used to predict indoor radon concentration with theoretical calculations. Since the major contributor of radon concentration in indoors originates from building materials used in construction of walls and floor which are mostly derived from soil. In this study different building materials have been analyzed for radon exhalation, diffusion length along with physical dimensions of observation area to calculate indoor radon concentration. Also calculated values have been validated by comparing with experimental measurements. The study has been carried out in the mud, brick and cement houses constructed from materials available locally in South-East region of Haryana. This region is also known for its protruding land structure consisting volcanic, felsite and granitic rocks in plane. Further, exhalation (Jw) ratio from wall and floor comparison has been plotted for each selected village dwelling to identify the high radon emanating source (building material) from the study region. All those measured factors might be useful in building construction code development and selection of material to be used in construction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quality in physical therapist clinical education: a systematic review.

PubMed

McCallum, Christine A; Mosher, Peter D; Jacobson, Peri J; Gallivan, Sean P; Giuffre, Suzanne M

2013-10-01

Many factors affect student learning throughout the clinical education (CE) component of professional (entry-level) physical therapist education curricula. Physical therapist education programs (PTEPs) manage CE, yet the material and human resources required to provide CE are generally overseen by community-based physical therapist practices. The purposes of this systematic review were: (1) to examine how the construct of quality is defined in CE literature and (2) to determine the methodological rigor of the available evidence on quality in physical therapist CE. This study was a systematic review of English-language journals using the American Physical Therapy Association's Open Door Portal to Evidence-Based Practice as the computer search engine. The search was categorized using terms for physical therapy and quality and for CE pedagogy and models or roles. Summary findings were characterized by 5 primary themes and 14 subthemes using a qualitative-directed content analysis. Fifty-four articles were included in the study. The primary quality themes were: CE framework, CE sites, structure of CE, assessment in CE, and CE faculty. The methodological rigor of the studies was critically appraised using a binary system based on the McMaster appraisal tools. Scores ranged from 3 to 14. Publication bias and outcome reporting bias may be inherent limitations to the results. The review found inconclusive evidence about what constitutes quality or best practice for physical therapist CE. Five key constructs of CE were identified that, when aggregated, could construe quality.

Physical activity levels at work and outside of work among Commercial Construction Workers

PubMed Central

Arias, Oscar E.; Caban-Martinez, Alberto J.; Umukoro, Peter E.; Okechukwu, Cassandra A.; Dennerlein, Jack T.

2015-01-01

Objective Characterize the number of minutes of moderate and vigorous physical activity at work and outside of work during seven consecutive days, in a sample of 55 commercial construction workers. Methods Workers wore accelerometers during work and outside work hours for seven consecutive days, and completed brief survey at the seventh day of data collection. Results From the directly measured physical activity, the average number per participant of moderate minutes of occupational physical activity and physical activity outside of work obtained in short bouts were 243 minutes (65%) and 130 minutes (35%), respectively. Directly measured minutes of vigorous occupational physical activity were significant and positively correlated with self-reported fatigue. Conclusions Among commercial construction workers, physical activity from work contributes significantly, approximately 2/3, towards a workers total amount of weekly minutes of moderate physical activity. PMID:25563543

Rasch model based analysis of the Force Concept Inventory

NASA Astrophysics Data System (ADS)

Planinic, Maja; Ivanjek, Lana; Susac, Ana

2010-06-01

The Force Concept Inventory (FCI) is an important diagnostic instrument which is widely used in the field of physics education research. It is therefore very important to evaluate and monitor its functioning using different tools for statistical analysis. One of such tools is the stochastic Rasch model, which enables construction of linear measures for persons and items from raw test scores and which can provide important insight in the structure and functioning of the test (how item difficulties are distributed within the test, how well the items fit the model, and how well the items work together to define the underlying construct). The data for the Rasch analysis come from the large-scale research conducted in 2006-07, which investigated Croatian high school students’ conceptual understanding of mechanics on a representative sample of 1676 students (age 17-18 years). The instrument used in research was the FCI. The average FCI score for the whole sample was found to be (27.7±0.4)% , indicating that most of the students were still non-Newtonians at the end of high school, despite the fact that physics is a compulsory subject in Croatian schools. The large set of obtained data was analyzed with the Rasch measurement computer software WINSTEPS 3.66. Since the FCI is routinely used as pretest and post-test on two very different types of population (non-Newtonian and predominantly Newtonian), an additional predominantly Newtonian sample ( N=141 , average FCI score of 64.5%) of first year students enrolled in introductory physics course at University of Zagreb was also analyzed. The Rasch model based analysis suggests that the FCI has succeeded in defining a sufficiently unidimensional construct for each population. The analysis of fit of data to the model found no grossly misfitting items which would degrade measurement. Some items with larger misfit and items with significantly different difficulties in the two samples of students do require further examination. The analysis revealed some problems with item distribution in the FCI and suggested that the FCI may function differently in non-Newtonian and predominantly Newtonian population. Some possible improvements of the test are suggested.

Validation of persuasive messages for the promotion of physical activity among people with coronary heart disease.

PubMed

Mendez, Roberto Della Rosa; Rodrigues, Roberta Cunha Matheus; Spana, Thaís Moreira; Cornélio, Marília Estevam; Gallani, Maria Cecília Bueno Jayme; Pérez-Nebra, Amalia Raquel

2012-01-01

to validate the content of persuasive messages for promoting walking among patients with coronary heart disease (CHD). The messages were constructed to strengthen or change patients' attitudes to walking. the selection of persuasive arguments was based on behavioral beliefs (determinants of attitude) related to walking. The messages were constructed based in the Elaboration Likelihood Model and were submitted to content validation. the data was analyzed with the content validity index and by the importance which the patients attributed to the messages' persuasive arguments. Positive behavioral beliefs (i.e. positive and negative reinforcement) and self-efficacy were the appeals which the patients considered important. The messages with validation evidence will be tested in an intervention study for the promotion of the practice of physical activity among patients with CHD.

Methodology to model the energy and greenhouse gas emissions of electronic software distributions.

PubMed

Williams, Daniel R; Tang, Yinshan

2012-01-17

A new electronic software distribution (ESD) life cycle analysis (LCA) methodology and model structure were constructed to calculate energy consumption and greenhouse gas (GHG) emissions. In order to counteract the use of high level, top-down modeling efforts, and to increase result accuracy, a focus upon device details and data routes was taken. In order to compare ESD to a relevant physical distribution alternative, physical model boundaries and variables were described. The methodology was compiled from the analysis and operational data of a major online store which provides ESD and physical distribution options. The ESD method included the calculation of power consumption of data center server and networking devices. An in-depth method to calculate server efficiency and utilization was also included to account for virtualization and server efficiency features. Internet transfer power consumption was analyzed taking into account the number of data hops and networking devices used. The power consumed by online browsing and downloading was also factored into the model. The embedded CO(2)e of server and networking devices was proportioned to each ESD process. Three U.K.-based ESD scenarios were analyzed using the model which revealed potential CO(2)e savings of 83% when ESD was used over physical distribution. Results also highlighted the importance of server efficiency and utilization methods.

Physics-based distributed snow models in the operational arena: Current and future challenges

NASA Astrophysics Data System (ADS)

Winstral, A. H.; Jonas, T.; Schirmer, M.; Helbig, N.

2017-12-01

The demand for modeling tools robust to climate change and weather extremes along with coincident increases in computational capabilities have led to an increase in the use of physics-based snow models in operational applications. Current operational applications include the WSL-SLF's across Switzerland, ASO's in California, and USDA-ARS's in Idaho. While the physics-based approaches offer many advantages there remain limitations and modeling challenges. The most evident limitation remains computation times that often limit forecasters to a single, deterministic model run. Other limitations however remain less conspicuous amidst the assumptions that these models require little to no calibration based on their foundation on physical principles. Yet all energy balance snow models seemingly contain parameterizations or simplifications of processes where validation data are scarce or present understanding is limited. At the research-basin scale where many of these models were developed these modeling elements may prove adequate. However when applied over large areas, spatially invariable parameterizations of snow albedo, roughness lengths and atmospheric exchange coefficients - all vital to determining the snowcover energy balance - become problematic. Moreover as we apply models over larger grid cells, the representation of sub-grid variability such as the snow-covered fraction adds to the challenges. Here, we will demonstrate some of the major sensitivities of distributed energy balance snow models to particular model constructs, the need for advanced and spatially flexible methods and parameterizations, and prompt the community for open dialogue and future collaborations to further modeling capabilities.

Quantitative critical thinking: Student activities using Bayesian updating

NASA Astrophysics Data System (ADS)

Warren, Aaron R.

2018-05-01

One of the central roles of physics education is the development of students' ability to evaluate proposed hypotheses and models. This ability is important not just for students' understanding of physics but also to prepare students for future learning beyond physics. In particular, it is often hoped that students will better understand the manner in which physicists leverage the availability of prior knowledge to guide and constrain the construction of new knowledge. Here, we discuss how the use of Bayes' Theorem to update the estimated likelihood of hypotheses and models can help achieve these educational goals through its integration with evaluative activities that use hypothetico-deductive reasoning. Several types of classroom and laboratory activities are presented that engage students in the practice of Bayesian likelihood updating on the basis of either consistency with experimental data or consistency with pre-established principles and models. This approach is sufficiently simple for introductory physics students while offering a robust mechanism to guide relatively sophisticated student reflection concerning models, hypotheses, and problem-solutions. A quasi-experimental study utilizing algebra-based introductory courses is presented to assess the impact of these activities on student epistemological development. The results indicate gains on the Epistemological Beliefs Assessment for Physical Science (EBAPS) at a minimal cost of class-time.

Gapped boundary phases of topological insulators via weak coupling

DOE PAGES

Seiberg, Nathan; Witten, Edward

2016-11-04

The standard boundary state of a topological insulator in 3 + 1 dimensions has gapless charged fermions. We present model systems that reproduce this standard gapless boundary state in one phase, but also have gapped phases with topological order. Our models are weakly coupled and all the dynamics is explicit. We rederive some known boundary states of topological insulators and construct new ones. Consistency with the standard spin/charge relation of condensed matter physics places a nontrivial constraint on models

Graphing in Physics: Processes and Sources of Error in Tertiary Entrance Examinations in Western Australia

ERIC Educational Resources Information Center

Forster, Patricia A.

2004-01-01

Interpretation and construction of graphs are central to the study of physics and to performance in physics. In this paper, I explore the interpretation and construction processes called upon in questions with a graphical component, in Western Australian Physics Tertiary Entrance Examinations. In addition, I list errors made by students as…

A Tale of Two Trails: Exploring Different Paths to Success

PubMed Central

Walker, Jennifer G.; Evenson, Kelly R.; Davis, William J.; Bors, Philip; Rodríguez, Daniel A.

2016-01-01

Background This comparative case study investigates 2 successful community trail initiatives, using the Active Living By Design (ALBD) Community Action Model as an analytical framework. The model includes 5 strategies: preparation, promotion, programs, policy, and physical projects. Methods Key stakeholders at 2 sites participated in in-depth interviews (N = 14). Data were analyzed for content using Atlas Ti and grouped according to the 5 strategies. Results Preparation Securing trail resources was challenging, but shared responsibilities facilitated trail development. Promotions The initiatives demonstrated minimal physical activity encouragement strategies. Programs Community stakeholders did not coordinate programmatic opportunities for routine physical activity. Policy Trails’ inclusion in regional greenway master plans contributed to trail funding and development. Policies that were formally institutionalized and enforced led to more consistent trail construction and safer conditions for users. Physical Projects Consistent standards for way finding signage and design safety features enhanced trail usability and safety. Conclusions Communities with different levels of government support contributed unique lessons to inform best practices of trail initiatives. This study revealed a disparity between trail development and use-encouragement strategies, which may limit trails’ impact on physical activity. The ALBD Community Action Model provided a viable framework to structure cross-disciplinary community trail initiatives. PMID:21597125

SubductionGenerator: A program to build three-dimensional plate configurations

NASA Astrophysics Data System (ADS)

Jadamec, M. A.; Kreylos, O.; Billen, M. I.; Turcotte, D. L.; Knepley, M.

2016-12-01

Geologic, geochemical, and geophysical data from subduction zones indicate that a two-dimensional paradigm for plate tectonic boundaries is no longer adequate to explain the observations. Many open source software packages exist to simulate the viscous flow of the Earth, such as the dynamics of subduction. However, there are few open source programs that generate the three-dimensional model input. We present an open source software program, SubductionGenerator, that constructs the three-dimensional initial thermal structure and plate boundary structure. A 3D model mesh and tectonic configuration are constructed based on a user specified model domain, slab surface, seafloor age grid file, and shear zone surface. The initial 3D thermal structure for the plates and mantle within the model domain is then constructed using a series of libraries within the code that use a half-space cooling model, plate cooling model, and smoothing functions. The code maps the initial 3D thermal structure and the 3D plate interface onto the mesh nodes using a series of libraries including a k-d tree to increase efficiency. In this way, complicated geometries and multiple plates with variable thickness can be built onto a multi-resolution finite element mesh with a 3D thermal structure and 3D isotropic shear zones oriented at any angle with respect to the grid. SubductionGenerator is aimed at model set-ups more representative of the earth, which can be particularly challenging to construct. Examples include subduction zones where the physical attributes vary in space, such as slab dip and temperature, and overriding plate temperature and thickness. Thus, the program can been used to construct initial tectonic configurations for triple junctions and plate boundary corners.

Object-Oriented Technology-Based Software Library for Operations of Water Reclamation Centers

NASA Astrophysics Data System (ADS)

Otani, Tetsuo; Shimada, Takehiro; Yoshida, Norio; Abe, Wataru

SCADA systems in water reclamation centers have been constructed based on hardware and software that each manufacturer produced according to their design. Even though this approach used to be effective to realize real-time and reliable execution, it is an obstacle to cost reduction about system construction and maintenance. A promising solution to address the problem is to set specifications that can be used commonly. In terms of software, information model approach has been adopted in SCADA systems in other field, such as telecommunications and power systems. An information model is a piece of software specification that describes a physical or logical object to be monitored. In this paper, we propose information models for operations of water reclamation centers, which have not ever existed. In addition, we show the feasibility of the information model in terms of common use and processing performance.

Classification without labels: learning from mixed samples in high energy physics

NASA Astrophysics Data System (ADS)

Metodiev, Eric M.; Nachman, Benjamin; Thaler, Jesse

2017-10-01

Modern machine learning techniques can be used to construct powerful models for difficult collider physics problems. In many applications, however, these models are trained on imperfect simulations due to a lack of truth-level information in the data, which risks the model learning artifacts of the simulation. In this paper, we introduce the paradigm of classification without labels (CWoLa) in which a classifier is trained to distinguish statistical mixtures of classes, which are common in collider physics. Crucially, neither individual labels nor class proportions are required, yet we prove that the optimal classifier in the CWoLa paradigm is also the optimal classifier in the traditional fully-supervised case where all label information is available. After demonstrating the power of this method in an analytical toy example, we consider a realistic benchmark for collider physics: distinguishing quark- versus gluon-initiated jets using mixed quark/gluon training samples. More generally, CWoLa can be applied to any classification problem where labels or class proportions are unknown or simulations are unreliable, but statistical mixtures of the classes are available.

Classification without labels: learning from mixed samples in high energy physics

DOE PAGES

Metodiev, Eric M.; Nachman, Benjamin; Thaler, Jesse

2017-10-25

Modern machine learning techniques can be used to construct powerful models for difficult collider physics problems. In many applications, however, these models are trained on imperfect simulations due to a lack of truth-level information in the data, which risks the model learning artifacts of the simulation. In this paper, we introduce the paradigm of classification without labels (CWoLa) in which a classifier is trained to distinguish statistical mixtures of classes, which are common in collider physics. Crucially, neither individual labels nor class proportions are required, yet we prove that the optimal classifier in the CWoLa paradigm is also the optimalmore » classifier in the traditional fully-supervised case where all label information is available. After demonstrating the power of this method in an analytical toy example, we consider a realistic benchmark for collider physics: distinguishing quark- versus gluon-initiated jets using mixed quark/gluon training samples. More generally, CWoLa can be applied to any classification problem where labels or class proportions are unknown or simulations are unreliable, but statistical mixtures of the classes are available.« less

Planning Model of Physics Learning In Senior High School To Develop Problem Solving Creativity Based On National Standard Of Education

NASA Astrophysics Data System (ADS)

Putra, A.; Masril, M.; Yurnetti, Y.

2018-04-01

One of the causes of low achievement of student’s competence in physics learning in high school is the process which they have not been able to develop student’s creativity in problem solving. This is shown that the teacher’s learning plan is not accordance with the National Eduction Standard. This study aims to produce a reconstruction model of physics learning that fullfil the competency standards, content standards, and assessment standards in accordance with applicable curriculum standards. The development process follows: Needs analysis, product design, product development, implementation, and product evaluation. The research process involves 2 peers judgment, 4 experts judgment and two study groups of high school students in Padang. The data obtained, in the form of qualitative and quantitative data that collected through documentation, observation, questionnaires, and tests. The result of this research up to the product development stage that obtained the physics learning plan model that meets the validity of the content and the validity of the construction in terms of the fulfillment of Basic Competence, Content Standards, Process Standards and Assessment Standards.

Classification without labels: learning from mixed samples in high energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metodiev, Eric M.; Nachman, Benjamin; Thaler, Jesse

Modern machine learning techniques can be used to construct powerful models for difficult collider physics problems. In many applications, however, these models are trained on imperfect simulations due to a lack of truth-level information in the data, which risks the model learning artifacts of the simulation. In this paper, we introduce the paradigm of classification without labels (CWoLa) in which a classifier is trained to distinguish statistical mixtures of classes, which are common in collider physics. Crucially, neither individual labels nor class proportions are required, yet we prove that the optimal classifier in the CWoLa paradigm is also the optimalmore » classifier in the traditional fully-supervised case where all label information is available. After demonstrating the power of this method in an analytical toy example, we consider a realistic benchmark for collider physics: distinguishing quark- versus gluon-initiated jets using mixed quark/gluon training samples. More generally, CWoLa can be applied to any classification problem where labels or class proportions are unknown or simulations are unreliable, but statistical mixtures of the classes are available.« less

A paradigm for modeling and computation of gas dynamics

NASA Astrophysics Data System (ADS)

Xu, Kun; Liu, Chang

2017-02-01

In the continuum flow regime, the Navier-Stokes (NS) equations are usually used for the description of gas dynamics. On the other hand, the Boltzmann equation is applied for the rarefied flow. These two equations are based on distinguishable modeling scales for flow physics. Fortunately, due to the scale separation, i.e., the hydrodynamic and kinetic ones, both the Navier-Stokes equations and the Boltzmann equation are applicable in their respective domains. However, in real science and engineering applications, they may not have such a distinctive scale separation. For example, around a hypersonic flying vehicle, the flow physics at different regions may correspond to different regimes, where the local Knudsen number can be changed significantly in several orders of magnitude. With a variation of flow physics, theoretically a continuous governing equation from the kinetic Boltzmann modeling to the hydrodynamic Navier-Stokes dynamics should be used for its efficient description. However, due to the difficulties of a direct modeling of flow physics in the scale between the kinetic and hydrodynamic ones, there is basically no reliable theory or valid governing equations to cover the whole transition regime, except resolving flow physics always down to the mean free path scale, such as the direct Boltzmann solver and the Direct Simulation Monte Carlo (DSMC) method. In fact, it is an unresolved problem about the exact scale for the validity of the NS equations, especially in the small Reynolds number cases. The computational fluid dynamics (CFD) is usually based on the numerical solution of partial differential equations (PDEs), and it targets on the recovering of the exact solution of the PDEs as mesh size and time step converging to zero. This methodology can be hardly applied to solve the multiple scale problem efficiently because there is no such a complete PDE for flow physics through a continuous variation of scales. For the non-equilibrium flow study, the direct modeling methods, such as DSMC, particle in cell, and smooth particle hydrodynamics, play a dominant role to incorporate the flow physics into the algorithm construction directly. It is fully legitimate to combine the modeling and computation together without going through the process of constructing PDEs. In other words, the CFD research is not only to obtain the numerical solution of governing equations but to model flow dynamics as well. This methodology leads to the unified gas-kinetic scheme (UGKS) for flow simulation in all flow regimes. Based on UGKS, the boundary for the validation of the Navier-Stokes equations can be quantitatively evaluated. The combination of modeling and computation provides a paradigm for the description of multiscale transport process.

[Characteristics of fugitive dust emission from paved road near construction activities].

PubMed

Tian, Gang; Fan, Shou-Bin; Li, Gang; Qin, Jian-Ping

2007-11-01

Because of the mud/dirt carryout from construction activities, the silt loading of paved road nearby is higher and the fugitive dust emission is stronger. By sampling and laboratory analysis of the road surface dust samples, we obtain the silt loading (mass of material equal to or less than 75 micromaters in physical diameter per unit area of travel surface) of paved roads near construction activities. The result show that silt loading of road near construction activities is higher than "normal road", and silt loading is negatively correlated with length from construction's door. According to AP-42 emission factor model of fugitive dust from roads, the emission factor of influenced road is 2 - 10 times bigger than "normal road", and the amount of fugitive dust emission influenced by one construction activity is "equivalent" to an additional road length of approximately 422 - 3 800 m with the baseline silt loading. Based on the spatial and temporal distribution of construction activities, in 2002 the amount of PM10 emission influenced by construction activities in Beijing city areas account of for 59% of fugitive dust from roads.

Scientific Inquiry Based Professional Development Models in Teacher Education

ERIC Educational Resources Information Center

Corlu, Mehmet Ali; Corlu, M. Sencer

2012-01-01

Scientific inquiry helps students develop critical thinking abilities and enables students to think and construct knowledge like a scientist. The study describes a method course implementation at a major public teachers college in Turkey. The main goal of the course was to improve research and teaching abilities of prospective physics teachers…

Diagnostic Opportunities Using Rasch Measurement in the Context of a Misconceptions-Based Physical Science Assessment

ERIC Educational Resources Information Center

Wind, Stefanie A.; Gale, Jessica D.

2015-01-01

Multiple-choice (MC) items that are constructed such that distractors target known misconceptions for a particular domain provide useful diagnostic information about student misconceptions (Herrmann-Abell & DeBoer, 2011, 2014; Sadler, 1998). Item response theory models can be used to examine misconceptions distractor-driven multiple-choice…

Constructing a 'Chromonome' of Yellowtail (Seriola quinqueradiata) for Comparative Analysis of Chromosomal Rearrangements

PubMed Central

Kawase, Junya; Aoki, Jun-ya; Araki, Kazuo

2018-01-01

To investigate chromosome evolution in fish species, we newly mapped 181 markers that allowed us to construct a yellowtail (Seriola quinqueradiata) radiation hybrid (RH) physical map with 1,713 DNA markers, which was far denser than a previous map, and we anchored the de novo assembled sequences onto the RH physical map. Finally, we mapped a total of 13,977 expressed sequence tags (ESTs) on a genome sequence assembly aligned with the physical map. Using the high-density physical map and anchored genome sequences, we accurately compared the yellowtail genome structure with the genome structures of five model fishes to identify characteristics of the yellowtail genome. Between yellowtail and Japanese medaka (Oryzias latipes), almost all regions of the chromosomes were conserved and some blocks comprising several markers were translocated. Using the genome information of the spotted gar (Lepisosteus oculatus) as a reference, we further documented syntenic relationships and chromosomal rearrangements that occurred during evolution in four other acanthopterygian species (Japanese medaka, zebrafish, spotted green pufferfish and three-spined stickleback). The evolutionary chromosome translocation frequency was 1.5-2-times higher in yellowtail than in medaka, pufferfish, and stickleback. PMID:29290830

Magnetohydrodynamic modelling of solar disturbances in the interplanetary medium

NASA Astrophysics Data System (ADS)

Dryer, M.

1985-12-01

A scientifically constructed series of interplanetary magnetohydrodynamic models is made that comprise the foundations for a composite solar terrestrial environment model. These models, unique in the field of solar wind physics, include both 2-1/2D as well as 3D time dependent codes that will lead to future operational status. We have also developed a geomagnetic storm forecasting strategy, referred to as the Solar Terrestrial Environment Model (STEM/2000), whereby these models would be appended in modular fashion to solar, magnetosphere, ionosphere, thermosphere, and neutral atmosphere models. We stress that these models, while still not appropriate at this date for operational use, outline a strategy or blueprint for the future. This strategy, if implemented in its essential features, offers a high probability for technology transfer from theory to operational testing within, approximately, a decade. It would ensure that real time observations would be used to drive physically based models that outputs of which would be used by space environment forecasters.

Gender differences in college leisure time physical activity: application of the theory of planned behavior and integrated behavioral model.

PubMed

Beville, Jill M; Meyer, M Renée Umstattd; Usdan, Stuart L; Turner, Lori W; Jackson, John C; Lian, Brad E

2014-01-01

National data consistently report that males participate in leisure time physical activity (LTPA) at higher rates than females. This study expanded previous research to examine gender differences in LTPA of college students using the theory of planned behavior (TPB) by including 2 additional constructs, descriptive norm and self-efficacy, from the integrated behavioral model. Participants were college students (N = 621) from a large public university in the southeastern United States. A self-report, classroom-based assessment with validated and reliable measures of LTPA, TPB constructs, descriptive norm, self-efficacy, and demographics was conducted in fall 2009. Regression analyses revealed attitude (β = .119), intention (β = .438), self-efficacy (β = .166), body mass index (BMI) (β = -.084), and sports participation (β = .081) as significantly associated with LTPA for females (R (2) = .425, p < .001), whereas intention (β = .371) was significant for males (R (2) = .202, p < .001). Practitioners should consider tailoring promotional materials to address these gender differences in efforts to increase LTPA participation among college students.

Multiple mediation path model of pain's cascading influence on physical disability in individuals with SCI from Colombia, South America.

PubMed

Perrin, Paul B; Paredes, Alejandra Morlett; Olivera, Silvia Leonor; Lozano, Juan Esteban; Leal, Wendy Tatiana; Ahmad, Usman F; Arango-Lasprilla, Juan Carlos

2017-01-01

Research has begun to document the bivariate connections between pain in individuals with spinal cord injury (SCI) and various aspects of health related quality of life (HRQOL), such as fatigue, social functioning, mental health, and physical functioning. The purpose of this study was to construct and test a theoretical path model illuminating the stage-wise and sequential (cascading) HRQOL pathways through which pain increases physical disability in individuals with SCI in a sample from Colombia, South America. It was hypothesized that increased pain would lead to decreased energy, which would lead to decreased mental health and social functioning, which both would lead to emotional role limitations, which finally would lead to physical role limitations. A cross-sectional study assessed individuals with SCI (n = 40) in Neiva, Colombia. Participants completed a measure indexing various aspects of HRQOL. The path model overall showed excellent fit indices, and each individual path within the model was statistically significant. Pain exerted significant indirect effects through all possible mediators in the model, ultimately suggesting that energy, mental health, social functioning, and role limitations-emotional were likely pathways through which pain exerted its effects on physical disability in individuals with SCI. These findings uncover several potential nodes for clinical intervention which if targeted in the context of rehabilitation or outpatient services, could result in salubrious direct and indirect effects reverberating down the theoretical causal chain and ultimately reducing physical disability in individuals with SCI.

Gendered Communities of Practice and the Construction of Masculinities in Turkish Physical Education

ERIC Educational Resources Information Center

Atencio, Matthew; Koca, Canan

2011-01-01

This paper analyses the construction of masculinities in Turkish physical education through Carrie Paechter's conceptualisation of gendered communities of practice. According to Paechter, educational communities of practice operate as sites of gendered activity. Membership within these communities contributes to the construction of a gendered…

Broadening the trans-contextual model of motivation: A study with Spanish adolescents.

PubMed

González-Cutre, D; Sicilia, Á; Beas-Jiménez, M; Hagger, M S

2014-08-01

The original trans-contextual model of motivation proposed that autonomy support from teachers develops students' autonomous motivation in physical education (PE), and that autonomous motivation is transferred from PE contexts to physical activity leisure-time contexts, and predicts attitudes, perceived behavioral control and subjective norms, and forming intentions to participate in future physical activity behavior. The purpose of this study was to test an extended trans-contextual model of motivation including autonomy support from peers and parents and basic psychological needs in a Spanish sample. School students (n = 400) aged between 12 and 18 years completed measures of perceived autonomy support from three sources, autonomous motivation and constructs from the theory of planned behavior at three different points in time and in two contexts, PE and leisure-time. A path analysis controlling for past physical activity behavior supported the main postulates of the model. Autonomous motivation in a PE context predicted autonomous motivation in a leisure-time physical activity context, perceived autonomy support from teachers predicted satisfaction of basic psychological needs in PE, and perceived autonomy support from peers and parents predicted need satisfaction in leisure-time. This study provides a cross-cultural replication of the trans-contextual model of motivation and broadens it to encompass basic psychological needs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The role of social capital in the relationship between physical constraint and mental distress in older adults: a latent interaction model.

PubMed

An, Sok; Jang, Yuri

2018-02-01

Building upon the widely known link between physical and mental health, the present study explored the buffering effects of social capital (indicated by social cohesion, social ties, and safety) in the relationship between physical constraint (indicated by chronic conditions and functional disability) and mental distress (indicated by symptoms of depression and anxiety). Using data from 2,264 community-dwelling older adults in the National Social Life, Health, and Aging Project (NSHAP) Wave 2 (M age = 74.51, SD = 6.67), a latent interaction model was tested. The model of mental distress, including both the main effect of physical constraint and social capital and their latent interaction, presented an excellent fit. The latent constructs of physical constraint (β = .54, p < .001) and social capital (β = -.11, p < .01) not only had a direct effect on mental distress, but their interaction was also significant (β = -.26, p < .001). Subgroup analysis showed that the group with a low level of social capital had a heightened vulnerability to mental distress when faced with physical constraint, whereas the group with a high level of social capital demonstrated resilience. Findings call attention to ways to enhance older individuals' social capital in efforts to promote their health and well-being.

Physical subspace in a model of the quantized electromagnetic field coupled to an external field with an indefinite metric

NASA Astrophysics Data System (ADS)

Suzuki, Akito

2008-04-01

We study a model of the quantized electromagnetic field interacting with an external static source ρ in the Feynman (Lorentz) gauge and construct the quantized radiation field Aμ (μ=0,1,2,3) as an operator-valued distribution acting on the Fock space F with an indefinite metric. By using the Gupta subsidiary condition ∂μAμ(x)(+)Ψ=0, one can select the physical subspace Vphys. According to the Gupta-Bleuler formalism, Vphys is a non-negative subspace so that elements of Vphys, called physical states, can be probabilistically interpretable. Indeed, assuming that the external source ρ is infrared regular, i.e., ρ̂/∣k∣3/2ɛL2(R3), we can characterize the physical subspace Vphys and show that Vphys is non-negative. In addition, we find that the Hamiltonian of the model is reduced to the Hamiltonian of the transverse photons with the Coulomb interaction. We, however, prove that the physical subspace is trivial, i.e., Vphys={0}, if and only if the external source ρ is infrared singular, i.e., ρ̂/∣k∣3/2∉L2(R3). We also discuss a representation different from the above representation such that the physical subspace is not trivial under the infrared singular condition.

Novel schemes for measurement-based quantum computation.

PubMed

Gross, D; Eisert, J

2007-06-01

We establish a framework which allows one to construct novel schemes for measurement-based quantum computation. The technique develops tools from many-body physics-based on finitely correlated or projected entangled pair states-to go beyond the cluster-state based one-way computer. We identify resource states radically different from the cluster state, in that they exhibit nonvanishing correlations, can be prepared using nonmaximally entangling gates, or have very different local entanglement properties. In the computational models, randomness is compensated in a different manner. It is shown that there exist resource states which are locally arbitrarily close to a pure state. We comment on the possibility of tailoring computational models to specific physical systems.

Critical look at physics identity: An operationalized framework for examining race and physics identity

NASA Astrophysics Data System (ADS)

Hyater-Adams, Simone; Fracchiolla, Claudia; Finkelstein, Noah; Hinko, Kathleen

2018-06-01

Studies on physics identity are appearing more frequently and often responding to increased awareness of the underrepresentation of students of color in physics. In our broader research, we focus our efforts on understanding how racial identity and physics identity are negotiated throughout the experiences of Black physicists. In this paper, we present a Critical Physics Identity framework that can be used to examine racialized physics identity and demonstrate the utility of this framework by analyzing interviews with four physicists. Our framework draws from prior constructs of physics identity and racialized identity and provides operational definitions of six interacting dimensions. In this paper, we present the operationalized constructs, demonstrate how we use these constructs to code narrative data, as well as outline three methods of analysis that may be applied to study systems and structures and their influences on the experiences of Black students.

Material and shape optimization for multi-layered vocal fold models using transient loadings.

PubMed

Schmidt, Bastian; Leugering, Günter; Stingl, Michael; Hüttner, Björn; Agaimy, Abbas; Döllinger, Michael

2013-08-01

Commonly applied models to study vocal fold vibrations in combination with air flow distributions are self-sustained physical models of the larynx consisting of artificial silicone vocal folds. Choosing appropriate mechanical parameters and layer geometries for these vocal fold models while considering simplifications due to manufacturing restrictions is difficult but crucial for achieving realistic behavior. In earlier work by Schmidt et al. [J. Acoust. Soc. Am. 129, 2168-2180 (2011)], the authors presented an approach in which material parameters of a static numerical vocal fold model were optimized to achieve an agreement of the displacement field with data retrieved from hemilarynx experiments. This method is now generalized to a fully transient setting. Moreover in addition to the material parameters, the extended approach is capable of finding optimized layer geometries. Depending on chosen material restriction, significant modifications of the reference geometry are predicted. The additional flexibility in the design space leads to a significantly more realistic deformation behavior. At the same time, the predicted biomechanical and geometrical results are still feasible for manufacturing physical vocal fold models consisting of several silicone layers. As a consequence, the proposed combined experimental and numerical method is suited to guide the construction of physical vocal fold models.

Machine learning to construct reduced-order models and scaling laws for reactive-transport applications

NASA Astrophysics Data System (ADS)

Mudunuru, M. K.; Karra, S.; Vesselinov, V. V.

2017-12-01

The efficiency of many hydrogeological applications such as reactive-transport and contaminant remediation vastly depends on the macroscopic mixing occurring in the aquifer. In the case of remediation activities, it is fundamental to enhancement and control of the mixing through impact of the structure of flow field which is impacted by groundwater pumping/extraction, heterogeneity, and anisotropy of the flow medium. However, the relative importance of these hydrogeological parameters to understand mixing process is not well studied. This is partially because to understand and quantify mixing, one needs to perform multiple runs of high-fidelity numerical simulations for various subsurface model inputs. Typically, high-fidelity simulations of existing subsurface models take hours to complete on several thousands of processors. As a result, they may not be feasible to study the importance and impact of model inputs on mixing. Hence, there is a pressing need to develop computationally efficient models to accurately predict the desired QoIs for remediation and reactive-transport applications. An attractive way to construct computationally efficient models is through reduced-order modeling using machine learning. These approaches can substantially improve our capabilities to model and predict remediation process. Reduced-Order Models (ROMs) are similar to analytical solutions or lookup tables. However, the method in which ROMs are constructed is different. Here, we present a physics-informed ML framework to construct ROMs based on high-fidelity numerical simulations. First, random forests, F-test, and mutual information are used to evaluate the importance of model inputs. Second, SVMs are used to construct ROMs based on these inputs. These ROMs are then used to understand mixing under perturbed vortex flows. Finally, we construct scaling laws for certain important QoIs such as degree of mixing and product yield. Scaling law parameters dependence on model inputs are evaluated using cluster analysis. We demonstrate application of the developed method for model analyses of reactive-transport and contaminant remediation at the Los Alamos National Laboratory (LANL) chromium contamination sites. The developed method is directly applicable for analyses of alternative site remediation scenarios.

Rethinking the Default Construction of Multimodel Climate Ensembles

DOE PAGES

Rauser, Florian; Gleckler, Peter; Marotzke, Jochem

2015-07-21

Here, we discuss the current code of practice in the climate sciences to routinely create climate model ensembles as ensembles of opportunity from the newest phase of the Coupled Model Intercomparison Project (CMIP). We give a two-step argument to rethink this process. First, the differences between generations of ensembles corresponding to different CMIP phases in key climate quantities are not large enough to warrant an automatic separation into generational ensembles for CMIP3 and CMIP5. Second, we suggest that climate model ensembles cannot continue to be mere ensembles of opportunity but should always be based on a transparent scientific decision process.more » If ensembles can be constrained by observation, then they should be constructed as target ensembles that are specifically tailored to a physical question. If model ensembles cannot be constrained by observation, then they should be constructed as cross-generational ensembles, including all available model data to enhance structural model diversity and to better sample the underlying uncertainties. To facilitate this, CMIP should guide the necessarily ongoing process of updating experimental protocols for the evaluation and documentation of coupled models. Finally, with an emphasis on easy access to model data and facilitating the filtering of climate model data across all CMIP generations and experiments, our community could return to the underlying idea of using model data ensembles to improve uncertainty quantification, evaluation, and cross-institutional exchange.« less

Making classical ground-state spin computing fault-tolerant.

PubMed

Crosson, I J; Bacon, D; Brown, K R

2010-09-01

We examine a model of classical deterministic computing in which the ground state of the classical system is a spatial history of the computation. This model is relevant to quantum dot cellular automata as well as to recent universal adiabatic quantum computing constructions. In its most primitive form, systems constructed in this model cannot compute in an error-free manner when working at nonzero temperature. However, by exploiting a mapping between the partition function for this model and probabilistic classical circuits we are able to show that it is possible to make this model effectively error-free. We achieve this by using techniques in fault-tolerant classical computing and the result is that the system can compute effectively error-free if the temperature is below a critical temperature. We further link this model to computational complexity and show that a certain problem concerning finite temperature classical spin systems is complete for the complexity class Merlin-Arthur. This provides an interesting connection between the physical behavior of certain many-body spin systems and computational complexity.

A synthetic seismicity model for the Middle America Trench

NASA Technical Reports Server (NTRS)

Ward, Steven N.

1991-01-01

A novel iterative technique, based on the concept of fault segmentation and computed using 2D static dislocation theory, for building models of seismicity and fault interaction which are physically acceptable and geometrically and kinematically correct, is presented. The technique is applied in two steps to seismicity observed at the Middle America Trench. The first constructs generic models which randomly draw segment strengths and lengths from a 2D probability distribution. The second constructs predictive models in which segment lengths and strengths are adjusted to mimic the actual geography and timing of large historical earthquakes. Both types of models reproduce the statistics of seismicity over five units of magnitude and duplicate other aspects including foreshock and aftershock sequences, migration of foci, and the capacity to produce both characteristic and noncharacteristic earthquakes. Over a period of about 150 yr the complex interaction of fault segments and the nonlinear failure conditions conspire to transform an apparently deterministic model into a chaotic one.

Relationship between achievement goal constructs and physical self-perceptions in a physical activity setting.

PubMed

Newton, Maria; Detling, Nicole; Kilgore, Jennifer; Bernhardt, Paul

2004-12-01

The relations of achievement goal theory constructs and physical self-perceptions were explored with 225 students (91 men, 109 women, and 25 nonindicators; M age=23.5 yr., SD=9.2), enrolled in basic physical activity classes (aerobics, weight training, modern dance, badminton, yoga, tai chi, basketball, racquetball, gymnastics, bowling, aquatone, and step aerobics) in a university setting. Goal orientations (Task and Ego Orientation in Sport Questionnaire), perceptions of the motivational climate (Perceived Motivational Climate in Sport Questionnaire-2), and physical self-perceptions (Physical Self-perception Profile) were assessed. Data were analyzed separately by sex. Ego orientation was the only predictor of Physical Self-perceptions in men, accounting for between 12 and 15% of the variance in Physical Self-worth, Sport Competence, Physical Conditioning, and Body Attractiveness. Constructs of achievement goal theory were not predictive of Physical Self-perceptions in the women. The results are discussed in light of achievement goal theory and the nature of the sample.

Theoretical Foundation for Weld Modeling

NASA Technical Reports Server (NTRS)

Traugott, S.

1986-01-01

Differential equations describe physics of tungsten/inert-gas and plasma-arc welding in aluminum. Report collects and describes necessary theoretical foundation upon which numerical welding model is constructed for tungsten/inert gas or plasma-arc welding in aluminum without keyhole. Governing partial differential equations for flow of heat, metal, and current given, together with boundary conditions relevant to welding process. Numerical estimates for relative importance of various phenomena and required properties of 2219 aluminum included

General Method for Constructing Local Hidden Variable Models for Entangled Quantum States

NASA Astrophysics Data System (ADS)

Cavalcanti, D.; Guerini, L.; Rabelo, R.; Skrzypczyk, P.

2016-11-01

Entanglement allows for the nonlocality of quantum theory, which is the resource behind device-independent quantum information protocols. However, not all entangled quantum states display nonlocality. A central question is to determine the precise relation between entanglement and nonlocality. Here we present the first general test to decide whether a quantum state is local, and show that the test can be implemented by semidefinite programing. This method can be applied to any given state and for the construction of new examples of states with local hidden variable models for both projective and general measurements. As applications, we provide a lower-bound estimate of the fraction of two-qubit local entangled states and present new explicit examples of such states, including those that arise from physical noise models, Bell-diagonal states, and noisy Greenberger-Horne-Zeilinger and W states.

"A Shock of Electricity Just Sort of Goes through My Body": Physical Activity and Embodied Reflexive Practices in Young Female Ballet Dancers

ERIC Educational Resources Information Center

Wellard, Ian; Pickard, Angela; Bailey, Richard

2007-01-01

Participation in physical activities, in and out of school, remains heavily influenced by social constructions of gendered behaviour. In addition, the body plays a significant part in the presentation of legitimate performances of physical practice and the construction of a physical "identity". The consequence is that in formalized…

Impact of Trichiasis Surgery on Physical Functioning in Ethiopian Patients: STAR Trial

PubMed Central

Wolle, Meraf A.; Cassard, Sandra D.; Gower, Emily W.; Munoz, Beatriz E.; Wang, Jiangxia; Alemayehu, Wondu; West, Sheila K.

2010-01-01

Purpose To evaluate the physical functioning of Ethiopian trichiasis surgery patients before and six months after surgery. Design Nested Cohort Study Methods This study was nested within the Surgery for Trichiasis, Antibiotics to Prevent Recurrence (STAR) clinical trial conducted in Ethiopia. Demographic information, ocular examinations, and physical functioning assessments were collected before and 6 months after surgery. A single score for patients’ physical functioning was constructed using Rasch analysis. A multivariate linear regression model was used to determine if change in physical functioning was associated with change in visual acuity. Results Of the 438 participants, 411 (93.8%) had both baseline and follow-up questionnaires. Physical functioning scores at baseline ranged from −6.32 (great difficulty) to +6.01 (no difficulty). The percent of participants reporting no difficulty in physical functioning increased by 32.6%; the proportion of participants in the mild/no visual impairment category increased by 8.6%. A multivariate linear regression model showed that for every line of vision gained, physical functioning improves significantly (0.09 units; 95% CI: 0.02–0.16). Conclusions Surgery to correct trichiasis appears to improve patients’ physical functioning as measured at 6 months. More effort in promoting trichiasis surgery is essential, not only to prevent corneal blindness, but also to enable improved functioning in daily life. PMID:21333268

Predictors of Segmented School Day Physical Activity and Sedentary Time in Children from a Northwest England Low-Income Community

PubMed Central

Taylor, Sarah L.; Curry, Whitney B.; Knowles, Zoe R.; Noonan, Robert J.; McGrane, Bronagh; Fairclough, Stuart J.

2017-01-01

Background: Schools have been identified as important settings for health promotion through physical activity participation, particularly as children are insufficiently active for health. The aim of this study was to investigate the child and school-level influences on children′s physical activity levels and sedentary time during school hours in a sample of children from a low-income community; Methods: One hundred and eighty-six children (110 boys) aged 9–10 years wore accelerometers for 7 days, with 169 meeting the inclusion criteria of 16 h∙day−1 for a minimum of three week days. Multilevel prediction models were constructed to identify significant predictors of sedentary time, light, and moderate to vigorous physical activity during school hour segments. Child-level predictors (sex, weight status, maturity offset, cardiorespiratory fitness, physical activity self-efficacy, physical activity enjoyment) and school-level predictors (number on roll, playground area, provision score) were entered into the models; Results: Maturity offset, fitness, weight status, waist circumference-to-height ratio, sedentary time, moderate to vigorous physical activity, number of children on roll and playground area significantly predicted physical activity and sedentary time; Conclusions: Research should move towards considering context-specific physical activity and its correlates to better inform intervention strategies. PMID:28509887

Combining Empirical and Stochastic Models for Extreme Floods Estimation

NASA Astrophysics Data System (ADS)

Zemzami, M.; Benaabidate, L.

2013-12-01

Hydrological models can be defined as physical, mathematical or empirical. The latter class uses mathematical equations independent of the physical processes involved in the hydrological system. The linear regression and Gradex (Gradient of Extreme values) are classic examples of empirical models. However, conventional empirical models are still used as a tool for hydrological analysis by probabilistic approaches. In many regions in the world, watersheds are not gauged. This is true even in developed countries where the gauging network has continued to decline as a result of the lack of human and financial resources. Indeed, the obvious lack of data in these watersheds makes it impossible to apply some basic empirical models for daily forecast. So we had to find a combination of rainfall-runoff models in which it would be possible to create our own data and use them to estimate the flow. The estimated design floods would be a good choice to illustrate the difficulties facing the hydrologist for the construction of a standard empirical model in basins where hydrological information is rare. The construction of the climate-hydrological model, which is based on frequency analysis, was established to estimate the design flood in the Anseghmir catchments, Morocco. The choice of using this complex model returns to its ability to be applied in watersheds where hydrological information is not sufficient. It was found that this method is a powerful tool for estimating the design flood of the watershed and also other hydrological elements (runoff, volumes of water...).The hydrographic characteristics and climatic parameters were used to estimate the runoff, water volumes and design flood for different return periods.

Inadequacy representation of flamelet-based RANS model for turbulent non-premixed flame

NASA Astrophysics Data System (ADS)

Lee, Myoungkyu; Oliver, Todd; Moser, Robert

2017-11-01

Stochastic representations for model inadequacy in RANS-based models of non-premixed jet flames are developed and explored. Flamelet-based RANS models are attractive for engineering applications relative to higher-fidelity methods because of their low computational costs. However, the various assumptions inherent in such models introduce errors that can significantly affect the accuracy of computed quantities of interest. In this work, we develop an approach to represent the model inadequacy of the flamelet-based RANS model. In particular, we pose a physics-based, stochastic PDE for the triple correlation of the mixture fraction. This additional uncertain state variable is then used to construct perturbations of the PDF for the instantaneous mixture fraction, which is used to obtain an uncertain perturbation of the flame temperature. A hydrogen-air non-premixed jet flame is used to demonstrate the representation of the inadequacy of the flamelet-based RANS model. This work was supported by DARPA-EQUiPS(Enabling Quantification of Uncertainty in Physical Systems) program.

The Challenge of Grounding Planning in Simulation with an Interactive Model Development Environment

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Frank, Jeremy D.; Chachere, John M.; Smith, Tristan B.; Swanson, Keith J.

2011-01-01

A principal obstacle to fielding automated planning systems is the difficulty of modeling. Physical systems are modeled conventionally based on specification documents and the modeler's understanding of the system. Thus, the model is developed in a way that is disconnected from the system's actual behavior and is vulnerable to manual error. Another obstacle to fielding planners is testing and validation. For a space mission, generated plans must be validated often by translating them into command sequences that are run in a simulation testbed. Testing in this way is complex and onerous because of the large number of possible plans and states of the spacecraft. Though, if used as a source of domain knowledge, the simulator can ease validation. This paper poses a challenge: to ground planning models in the system physics represented by simulation. A proposed, interactive model development environment illustrates the integration of planning and simulation to meet the challenge. This integration reveals research paths for automated model construction and validation.

Earthquake cycles and physical modeling of the process leading up to a large earthquake

NASA Astrophysics Data System (ADS)

Ohnaka, Mitiyasu

2004-08-01

A thorough discussion is made on what the rational constitutive law for earthquake ruptures ought to be from the standpoint of the physics of rock friction and fracture on the basis of solid facts observed in the laboratory. From this standpoint, it is concluded that the constitutive law should be a slip-dependent law with parameters that may depend on slip rate or time. With the long-term goal of establishing a rational methodology of forecasting large earthquakes, the entire process of one cycle for a typical, large earthquake is modeled, and a comprehensive scenario that unifies individual models for intermediate-and short-term (immediate) forecasts is presented within the framework based on the slip-dependent constitutive law and the earthquake cycle model. The earthquake cycle includes the phase of accumulation of elastic strain energy with tectonic loading (phase II), and the phase of rupture nucleation at the critical stage where an adequate amount of the elastic strain energy has been stored (phase III). Phase II plays a critical role in physical modeling of intermediate-term forecasting, and phase III in physical modeling of short-term (immediate) forecasting. The seismogenic layer and individual faults therein are inhomogeneous, and some of the physical quantities inherent in earthquake ruptures exhibit scale-dependence. It is therefore critically important to incorporate the properties of inhomogeneity and physical scaling, in order to construct realistic, unified scenarios with predictive capability. The scenario presented may be significant and useful as a necessary first step for establishing the methodology for forecasting large earthquakes.

Building and Characterizing Volcanic Landscapes with a Numerical Landscape Evolution Model and Spectral Techniques

NASA Astrophysics Data System (ADS)

Richardson, P. W.; Karlstrom, L.

2016-12-01

The competition between constructional volcanic processes such as lava flows, cinder cones, and tumuli compete with physical and chemical erosional processes to control the morphology of mafic volcanic landscapes. If volcanic effusion rates are high, these landscapes are primarily constructional, but over the timescales associated with hot spot volcanism (1-10 Myr) and arcs (10-50 Myr), chemical and physical erosional processes are important. For fluvial incision to occur, initially high infiltration rates must be overcome by chemical weathering or input of fine-grained sediment. We investigate lava flow resurfacing, using a new lava flow algorithm that can be calibrated for specific flows and eruption magnitude/frequency relationships, into a landscape evolution model to complete two modeling experiments to investigate the interplay between volcanic resurfacing and fluvial incision. We use a stochastic spatial vent distribution calibrated from the Hawaiian eruption record to resurface a synthetically produced ocean island. In one experiment, we investigate the consequences of including time-dependent channel incision efficiency. This effectively mimics the behavior of transient hydrological development of lava flows. In the second experiment, we explore the competition between channel incision and lava flow resurfacing. The relative magnitudes of channel incision versus lava flow resurfacing are captured in landscape topography. For example, during the shield building period for ocean islands, effusion rates are high and the signature of lava flow resurfacing dominates. In contrast, after the shield building phase, channel incision begins and eventually dominates the topographic signature. We develop a dimensionless ratio of resurfacing rate to erosion rate to characterize the transition between these processes. We use spectral techniques to characterize volcanic features and to pinpoint the transition between constructional and erosional morphology on modeled landscapes and on the Big Island of Hawaii.

42 CFR 485.623 - Condition of participation: Physical plant and environment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 5 2013-10-01 2013-10-01 false Condition of participation: Physical plant and environment. 485.623 Section 485.623 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF... participation: Physical plant and environment. (a) Standard: Construction. The CAH is constructed, arranged, and...

42 CFR 485.623 - Condition of participation: Physical plant and environment.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 5 2014-10-01 2014-10-01 false Condition of participation: Physical plant and environment. 485.623 Section 485.623 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF... participation: Physical plant and environment. (a) Standard: Construction. The CAH is constructed, arranged, and...

42 CFR 485.623 - Condition of participation: Physical plant and environment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 5 2011-10-01 2011-10-01 false Condition of participation: Physical plant and environment. 485.623 Section 485.623 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF... participation: Physical plant and environment. (a) Standard: Construction. The CAH is constructed, arranged, and...

42 CFR 485.623 - Condition of participation: Physical plant and environment.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 5 2012-10-01 2012-10-01 false Condition of participation: Physical plant and environment. 485.623 Section 485.623 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF... participation: Physical plant and environment. (a) Standard: Construction. The CAH is constructed, arranged, and...

High school students' scientific epistemological beliefs, self-efficacy in learning physics and attitudes toward physics: a structural equation model

NASA Astrophysics Data System (ADS)

Kapucu, Serkan; Bahçivan, Eralp

2015-05-01

Background: There are some theoretical evidences that explain the relationships between core beliefs (i.e., epistemological beliefs) and peripheral beliefs (self-efficacy in learning) in the literature. The close relationships of such type of beliefs with attitudes are also discussed by some researchers. Constructing a model that investigates these relationships by considering theoretical and empirical evidences can empower researchers to discuss these relationships more comprehensively. Purpose: The purpose of this study is to explore the relationships among Turkish high school students' scientific epistemological beliefs, self-efficacy in learning physics and their attitudes toward physics. Sample: A total of 632 high school students participated in this study; however, 269 female and 229 male (a total of 498) high school students' data were used. Design and methods: Three distinct instruments that measure scientific epistemological beliefs, self-efficacy in learning physics and attitudes toward physics were combined into a unique questionnaire form and it was distributed to high school students. To explore the relationships among these variables, structural equation modeling was used. Results: The results showed that scientific epistemological belief dimensions uncovered by the nature of knowing (source and justification) significantly and positively related to both self-efficacy in learning physics and attitudes toward other important physics dimensions. Additionally, self-efficacy in learning physics significantly and positively predicted attitudes toward multiple physics dimensions (importance, comprehension and requirement). However, epistemological belief dimensions related to the nature of knowledge (certainty and development) did not have significant impact on self-efficacy in learning physics or attitudes toward physics. Conclusions: This study concludes that there are positive and significant relationships among Turkish high school students' scientific epistemological beliefs, self-efficacy in learning physics and their attitudes toward physics.

Psychological theory in an interdisciplinary context: psychological, demographic, health-related, social, and environmental correlates of physical activity in a representative cohort of community-dwelling older adults.

PubMed

Sniehotta, Falko F; Gellert, Paul; Witham, Miles D; Donnan, Peter T; Crombie, Iain K; McMurdo, Marion E T

2013-09-08

Physical activity (PA) in older adults is influenced by a range of environmental, demographic, health-related, social, and psychological variables. Social cognitive psychological models assume that all influences on behaviour operate indirectly through the models constructs, i.e., via intention and self-efficacy. We evaluated direct, indirect, and moderating relationships of a broad range of external variables with physical activity levels alongside intention and self-efficacy. We performed a cross-sectional survey of a representative and stratified (65-80 and 80+ years; deprived and affluent) sample of 584 community-dwelling people, resident in Scotland. Objectively measured physical activity and questionnaire data were collected. Self-efficacy showed unique relationships with physical activity, controlling for demographic, mental health, social, environmental, and weather variables separately, but the relationship was not significant when controlling for physical health. Overall, results indicating support for a mediation hypothesis, intention and self-efficacy statistically mediate the relationship of most domain variables with physical activity. Moderation analyses show that the relationship between social cognitions and physical activity was stronger for individuals with better physical health and lower levels of socio-economic deprivation. Social cognitive variables reflect a range of known environmental, demographic, health-related and social correlates of physical activity, they mediate the relationships of those correlates with physical activity and account for additional variance in physical activity when external correlates are controlled for, except for the physical health domain. The finding that the social cognition-physical activity relationship is higher for participants with better health and higher levels of affluence raises issues for the applicability of social cognitive models to the most disadvantaged older people.

Against the current: Women of color succeeding in physics

NASA Astrophysics Data System (ADS)

Ong, Maria Theresa

2002-09-01

What are the social conditions for membership in physics? How do constructions of scientific identities engage with racial and gendered constructions of the body? What work is involved in the occupation of multiple social sites, such as for women of color in physics? This work addresses these questions through a six-year, longitudinal qualitative project originally including over four hundred students and focusing on ten successful female minority physics majors at a large, diverse, top-tier public research institution. The study develops a theory of embodied social practice that examines the co-constructions of cultures, agency, and identities in the process of becoming a physicist. In particular, the experiences of multiply marginalized members, women of color physics majors, are used as a lens to see invisible but contingent factors for membership in the local physics culture. Key gatekeeping mechanisms regulating this membership are identified; also described are individual and institutional responses that enable young, traditional outsiders to continue to succeed on school and career trajectories in physics. First, women of color come to understand that the notion of competence is readily granted to men (and, to a much lesser degree, to nonminority women) but denied to them. In response, they learn to maneuver their bodies and voices as strategically pliable tools to perform belonging and scientific knowledge by either complying with or disrupting locally acceptable norms of ethnicity and heterosexual maleness and femaleness. Next, women of color often face disempowerment due to their invisibility imposed by peers and faculty. However, they are not passive recipients; they often manipulate their in/visibility for purposes of accessing and maintaining physics membership. Finally, they persist in the field by accruing cultural and social capital in innovative ways for themselves, each other, and future generations of women and minority scientists. Their activities and growing presence in the field are helping to transform the demographics and practices of physics into a more diverse and inclusive culture. The conclusions discuss these issues in the current context of unversities' search for positive models of outreach and retention and the ongoing political backlash against minorities.

Male sexual strategies modify ratings of female models with specific waist-to-hip ratios.

PubMed

Brase, Gary L; Walker, Gary

2004-06-01

Female waist-to-hip ratio (WHR) has generally been an important general predictor of ratings of physical attractiveness and related characteristics. Individual differences in ratings do exist, however, and may be related to differences in the reproductive tactics of the male raters such as pursuit of short-term or long-term relationships and adjustments based on perceptions of one's own quality as a mate. Forty males, categorized according to sociosexual orientation and physical qualities (WHR, Body Mass Index, and self-rated desirability), rated female models on both attractiveness and likelihood they would approach them. Sociosexually restricted males were less likely to approach females rated as most attractive (with 0.68-0.72 WHR), as compared with unrestricted males. Males with lower scores in terms of physical qualities gave ratings indicating more favorable evaluations of female models with lower WHR. The results indicate that attractiveness and willingness to approach are overlapping but distinguishable constructs, both of which are influenced by variations in characteristics of the raters.

Predicting Self-Management Behaviors in Familial Hypercholesterolemia Using an Integrated Theoretical Model: the Impact of Beliefs About Illnesses and Beliefs About Behaviors.

PubMed

Hagger, Martin S; Hardcastle, Sarah J; Hingley, Catherine; Strickland, Ella; Pang, Jing; Watts, Gerald F

2016-06-01

Patients with familial hypercholesterolemia (FH) are at markedly increased risk of coronary artery disease. Regular participation in three self-management behaviors, physical activity, healthy eating, and adherence to medication, can significantly reduce this risk in FH patients. We aimed to predict intentions to engage in these self-management behaviors in FH patients using a multi-theory, integrated model that makes the distinction between beliefs about illness and beliefs about self-management behaviors. Using a cross-sectional, correlational design, patients (N = 110) diagnosed with FH from a clinic in Perth, Western Australia, self-completed a questionnaire that measured constructs from three health behavior theories: the common sense model of illness representations (serious consequences, timeline, personal control, treatment control, illness coherence, emotional representations); theory of planned behavior (attitudes, subjective norms, perceived behavioral control); and social cognitive theory (self-efficacy). Structural equation models for each self-management behavior revealed consistent and statistically significant effects of attitudes on intentions across the three behaviors. Subjective norms predicted intentions for health eating only and self-efficacy predicted intentions for physical activity only. There were no effects for the perceived behavioral control and common sense model constructs in any model. Attitudes feature prominently in determining intentions to engage in self-management behaviors in FH patients. The prominence of these attitudinal beliefs about self-management behaviors, as opposed to illness beliefs, suggest that addressing these beliefs may be a priority in the management of FH.

A full-spectrum analysis of high-speed train interior noise under multi-physical-field coupling excitations

NASA Astrophysics Data System (ADS)

Zheng, Xu; Hao, Zhiyong; Wang, Xu; Mao, Jie

2016-06-01

High-speed-railway-train interior noise at low, medium, and high frequencies could be simulated by finite element analysis (FEA) or boundary element analysis (BEA), hybrid finite element analysis-statistical energy analysis (FEA-SEA) and statistical energy analysis (SEA), respectively. First, a new method named statistical acoustic energy flow (SAEF) is proposed, which can be applied to the full-spectrum HST interior noise simulation (including low, medium, and high frequencies) with only one model. In an SAEF model, the corresponding multi-physical-field coupling excitations are firstly fully considered and coupled to excite the interior noise. The interior noise attenuated by sound insulation panels of carriage is simulated through modeling the inflow acoustic energy from the exterior excitations into the interior acoustic cavities. Rigid multi-body dynamics, fast multi-pole BEA, and large-eddy simulation with indirect boundary element analysis are first employed to extract the multi-physical-field excitations, which include the wheel-rail interaction forces/secondary suspension forces, the wheel-rail rolling noise, and aerodynamic noise, respectively. All the peak values and their frequency bands of the simulated acoustic excitations are validated with those from the noise source identification test. Besides, the measured equipment noise inside equipment compartment is used as one of the excitation sources which contribute to the interior noise. Second, a full-trimmed FE carriage model is firstly constructed, and the simulated modal shapes and frequencies agree well with the measured ones, which has validated the global FE carriage model as well as the local FE models of the aluminum alloy-trim composite panel. Thus, the sound transmission loss model of any composite panel has indirectly been validated. Finally, the SAEF model of the carriage is constructed based on the accurate FE model and stimulated by the multi-physical-field excitations. The results show that the trend of the simulated 1/3 octave band sound pressure spectrum agrees well with that of the on-site-measured one. The deviation between the simulated and measured overall sound pressure level (SPL) is 2.6 dB(A) and well controlled below the engineering tolerance limit, which has validated the SAEF model in the full-spectrum analysis of the high speed train interior noise.

Between tide and wave marks: a unifying model of physical zonation on littoral shores

PubMed Central

Bird, Christopher E.; Franklin, Erik C.; Smith, Celia M.

2013-01-01

The effects of tides on littoral marine habitats are so ubiquitous that shorelines are commonly described as ‘intertidal’, whereas waves are considered a secondary factor that simply modifies the intertidal habitat. However mean significant wave height exceeds tidal range at many locations worldwide. Here we construct a simple sinusoidal model of coastal water level based on both tidal range and wave height. From the patterns of emergence and submergence predicted by the model, we derive four vertical shoreline benchmarks which bracket up to three novel, spatially distinct, and physically defined zones. The (1) emergent tidal zone is characterized by tidally driven emergence in air; the (2) wave zone is characterized by constant (not periodic) wave wash; and the (3) submergent tidal zone is characterized by tidally driven submergence. The decoupling of tidally driven emergence and submergence made possible by wave action is a critical prediction of the model. On wave-dominated shores (wave height ≫ tidal range), all three zones are predicted to exist separately, but on tide-dominated shores (tidal range ≫ wave height) the wave zone is absent and the emergent and submergent tidal zones overlap substantially, forming the traditional “intertidal zone”. We conclude by incorporating time and space in the model to illustrate variability in the physical conditions and zonation on littoral shores. The wave:tide physical zonation model is a unifying framework that can facilitate our understanding of physical conditions on littoral shores whether tropical or temperate, marine or lentic. PMID:24109544

Evolution of Pre-Main Sequence Accretion Disks

NASA Technical Reports Server (NTRS)

Hartmann, Lee W.

2004-01-01

The aim of this project is to develop a comprehensive global picture of the physical conditions in, and evolutionary timescales of, pre-main sequence accretion disks. The results of this work will help constrain the initial conditions for planet formation. To this end we are developing much larger samples of 3-10 Myr-old stars to provide better empirical constraints on protoplanetary disk evolution; measuring disk accretion rates in these systems; and constructing detailed model disk structures consistent with observations to infer physical conditions such as grain growth in protoplanetary disks.

Evolution of Pre-Main Sequence Accretion Disks

NASA Technical Reports Server (NTRS)

Hartmann, Lee W.

2003-01-01

The aim of this project is to develop a comprehensive global picture of the physical conditions in, and evolutionary timescales of, pre-main sequence accretion disks. The results of this work will help constrain the initial conditions for planet formation. To this end we are developing much larger samples of 3-10 Myr-old stars to provide better empirical constraints on protoplanetary disk evolution; measuring disk accretion rates in these systems; and constructing detailed model disk structures consistent with observations to infer physical conditions such as grain growth in protoplanetary disks.

Evolution of Pre-Main Sequence Accretion Disks

NASA Technical Reports Server (NTRS)

Hartmann, Lee W.

2005-01-01

The aim of this project was to develop a comprehensive global picture of the physical conditions in, and evolutionary timescales of, premain sequence accretion disks. The results of this work will help constrain the initial conditions for planet formation. To this end we developed much larger samples of 3-10 Myr-old stars to provide better empirical constraints on protoplanetary disk evolution; measured disk accretion rates in these systems; and constructed detailed model disk structures consistent with observations to infer physical conditions such as grain growth in protoplanetary disks.

Studies of Circumstellar Disk Evolution

NASA Technical Reports Server (NTRS)

Hartmann, Lee W.

2005-01-01

The aim of this project is to develop a comprehensive global picture of the physical conditions in, and evolutionary timescales of, pre-main sequence accretion disks. The results of this work will help constrain the initial conditions for planet formation. To this end we are developing much larger samples of 3-10 Myr-old stars to provide better empirical constraints on protoplanetary disk evolution; measuring disk accretion rates in these systems; and constructing detailed model disk structures consistent with observations to infer physical conditions such as grain growth in protoplanetary disks.

Confirmatory Factor Analysis of the WHO Violence Against Women Instrument in Pregnant Women: Results from the BRISA Prenatal Cohort

PubMed Central

Ribeiro, Marizélia Rodrigues Costa; Alves, Maria Teresa Seabra Soares de Britto e.; Batista, Rosângela Fernandes Lucena; Ribeiro, Cecília Cláudia Costa; Schraiber, Lilia Blima; Barbieri, Marco Antônio; Bettiol, Heloisa; da Silva, Antônio Augusto Moura

2014-01-01

Background Screening for violence during pregnancy is one of the strategies for the prevention of abuse against women. Since violence is difficult to measure, it is necessary to validate questionnaires that can provide a good measure of the phenomenon. The present study analyzed the psychometric properties of the World Health Organization Violence Against Women (WHO VAW) instrument for the measurement of violence against pregnant women. Methods Data from the Brazilian Ribeirão Preto and São Luís birth cohort studies (BRISA) were used. The sample consisted of 1,446 pregnant women from São Luís and 1,378 from Ribeirão Preto, interviewed in 2010 and 2011. Thirteen variables were selected from a self-applied questionnaire. Confirmatory factor analysis was used to investigate whether violence is a uni-or-multidimensional construct consisting of psychological, physical and sexual dimensions. The mean-and-variance-adjusted weighted least squares estimator was used. Models were fitted separately for each city and a third model combining data from the two settings was also tested. Models suggested from modification indices were tested to determine whether changes in the WHO VAW model would produce a better fit. Results The unidimensional model did not show good fit (Root mean square error of approximation [RMSEA]  = 0.060, p<0.001 for the combined model). The multidimensional WHO VAW model showed good fit (RMSEA = 0.036, p = 0.999 for the combined model) and standardized factor loadings higher than 0.70, except for the sexual dimension for SL (0.65). The models suggested by the modification indices with cross loadings measuring simultaneously physical and psychological violence showed a significantly better fit compared to the original WHO model (p<0.001 for the difference between the model chi-squares). Conclusions Violence is a multidimensional second-order construct consisting of psychological, physical and sexual dimensions. The WHO VAW model and the modified models are suitable for measuring violence against pregnant women. PMID:25531654

Model structure of the stream salmonid simulator (S3)—A dynamic model for simulating growth, movement, and survival of juvenile salmonids

USGS Publications Warehouse

Perry, Russell W.; Plumb, John M.; Jones, Edward C.; Som, Nicholas A.; Hetrick, Nicholas J.; Hardy, Thomas B.

2018-04-06

Fisheries and water managers often use population models to aid in understanding the effect of alternative water management or restoration actions on anadromous fish populations. We developed the Stream Salmonid Simulator (S3) to help resource managers evaluate the effect of management alternatives on juvenile salmonid populations. S3 is a deterministic stage-structured population model that tracks daily growth, movement, and survival of juvenile salmon. A key theme of the model is that river flow affects habitat availability and capacity, which in turn drives density dependent population dynamics. To explicitly link population dynamics to habitat quality and quantity, the river environment is constructed as a one-dimensional series of linked habitat units, each of which has an associated daily time series of discharge, water temperature, and usable habitat area or carrying capacity. The physical characteristics of each habitat unit and the number of fish occupying each unit, in turn, drive survival and growth within each habitat unit and movement of fish among habitat units.The purpose of this report is to outline the underlying general structure of the S3 model that is common among different applications of the model. We have developed applications of the S3 model for juvenile fall Chinook salmon (Oncorhynchus tshawytscha) in the lower Klamath River. Thus, this report is a companion to current application of the S3 model to the Trinity River (in review). The general S3 model structure provides a biological and physical framework for the salmonid freshwater life cycle. This framework captures important demographics of juvenile salmonids aimed at translating management alternatives into simulated population responses. Although the S3 model is built on this common framework, the model has been constructed to allow much flexibility in application of the model to specific river systems. The ability for practitioners to include system-specific information for the physical stream structure, survival, growth, and movement processes ensures that simulations provide results that are relevant to the questions asked about the population under study.

Microfissuring of Inconel 718

NASA Technical Reports Server (NTRS)

Nunes, A. C., Jr.

1983-01-01

A tentative mathematical computer model of the microfissuring process during electron beam welding of Inconel 718 has been constructed. Predictions of the model are compatible with microfissuring tests on eight 0.25-in. thick test plates. The model takes into account weld power and speed, weld loss (efficiency), parameters and material characteristics. Besides the usual material characteristics (thermal and strength properties), a temperature and grain size dependent critical fracture strain is required by the model. The model is based upon fundamental physical theory (i.e., it is not a mere data interpolation system), and can be extended to other metals by suitable parameter changes.

An Incremental Weighted Least Squares Approach to Surface Lights Fields

NASA Astrophysics Data System (ADS)

Coombe, Greg; Lastra, Anselmo

An Image-Based Rendering (IBR) approach to appearance modelling enables the capture of a wide variety of real physical surfaces with complex reflectance behaviour. The challenges with this approach are handling the large amount of data, rendering the data efficiently, and previewing the model as it is being constructed. In this paper, we introduce the Incremental Weighted Least Squares approach to the representation and rendering of spatially and directionally varying illumination. Each surface patch consists of a set of Weighted Least Squares (WLS) node centers, which are low-degree polynomial representations of the anisotropic exitant radiance. During rendering, the representations are combined in a non-linear fashion to generate a full reconstruction of the exitant radiance. The rendering algorithm is fast, efficient, and implemented entirely on the GPU. The construction algorithm is incremental, which means that images are processed as they arrive instead of in the traditional batch fashion. This human-in-the-loop process enables the user to preview the model as it is being constructed and to adapt to over-sampling and under-sampling of the surface appearance.

Effectiveness of an intervention at construction worksites on work engagement, social support, physical workload, and need for recovery: results from a cluster randomized controlled trial

PubMed Central

2012-01-01

Background To prolong sustainable healthy working lives of construction workers, a worksite prevention program was developed which aimed to improve the health and work ability of construction workers. The aim of the current study was to investigate the effectiveness of this program on social support at work, work engagement, physical workload and need for recovery. Methods Fifteen departments from six construction companies participated in this cluster randomized controlled trial; 8 departments (n=171 workers) were randomized to an intervention group and 7 departments (n=122 workers) to a control group. The intervention consisted of two individual training sessions of a physical therapist to lower the physical workload, a Rest-Break tool to improve the balance between work and recovery, and two empowerment training sessions to increase the influence of the construction workers at the worksite. Data on work engagement, social support at work, physical workload, and need for recovery were collected at baseline, and at three, six and 12 months after the start of the intervention using questionnaires. Results No differences between the intervention and control group were found for work engagement, social support at work, and need for recovery. At 6 months follow-up, the control group reported a small but statistically significant reduction of physical workload. Conclusion The intervention neither improved social support nor work engagement, nor was it effective in reducing the physical workload and need for recovery among construction workers. Trial registration NTR1278 PMID:23171354

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchanan, Charles D.; Cline, David B.; Byers, N.

Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics;more » (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R D.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics;more » (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R & D.« less

Physics Based Modeling and Rendering of Vegetation in the Thermal Infrared

NASA Technical Reports Server (NTRS)

Smith, J. A.; Ballard, J. R., Jr.

1999-01-01

We outline a procedure for rendering physically-based thermal infrared images of simple vegetation scenes. Our approach incorporates the biophysical processes that affect the temperature distribution of the elements within a scene. Computer graphics plays a key role in two respects. First, in computing the distribution of scene shaded and sunlit facets and, second, in the final image rendering once the temperatures of all the elements in the scene have been computed. We illustrate our approach for a simple corn scene where the three-dimensional geometry is constructed based on measured morphological attributes of the row crop. Statistical methods are used to construct a representation of the scene in agreement with the measured characteristics. Our results are quite good. The rendered images exhibit realistic behavior in directional properties as a function of view and sun angle. The root-mean-square error in measured versus predicted brightness temperatures for the scene was 2.1 deg C.

Learning and teaching science as inquiry: A case study of elementary school teachers' investigations of light

NASA Astrophysics Data System (ADS)

van Zee, Emily H.; Hammer, David; Bell, Mary; Roy, Patricia; Peter, Jennifer

2005-11-01

This case study documents an example of inquiry learning and teaching during a summer institute for elementary and middle school teachers. A small group constructed an explanatory model for an intriguing optical phenomenon that they were observing. Research questions included: What physics thinking did the learners express? What aspects of scientific inquiry were evident in what the learners said and did? What questions did the learners ask one another as they worked? How did these learners collaborate in constructing understanding? How did the instructor foster their learning? Data sources included video- and audio- tapes of instruction, copies of the participants' writings and drawings, field notes, interviews, and staff reflections. An interpretative narrative of what three group members said and did presents a detailed account of their learning process. Analyses of their utterances provide evidence of physics thinking, scientific inquiry, questioning, collaborative sense making, and insight into ways to foster inquiry learning.

Technical integration of hippocampus, Basal Ganglia and physical models for spatial navigation.

PubMed

Fox, Charles; Humphries, Mark; Mitchinson, Ben; Kiss, Tamas; Somogyvari, Zoltan; Prescott, Tony

2009-01-01

Computational neuroscience is increasingly moving beyond modeling individual neurons or neural systems to consider the integration of multiple models, often constructed by different research groups. We report on our preliminary technical integration of recent hippocampal formation, basal ganglia and physical environment models, together with visualisation tools, as a case study in the use of Python across the modelling tool-chain. We do not present new modeling results here. The architecture incorporates leaky-integrator and rate-coded neurons, a 3D environment with collision detection and tactile sensors, 3D graphics and 2D plots. We found Python to be a flexible platform, offering a significant reduction in development time, without a corresponding significant increase in execution time. We illustrate this by implementing a part of the model in various alternative languages and coding styles, and comparing their execution times. For very large-scale system integration, communication with other languages and parallel execution may be required, which we demonstrate using the BRAHMS framework's Python bindings.

Atomistic modeling of crystal-to-amorphous transition and associated kinetics in the Ni-Nb system by molecular dynamics simulations.

PubMed

Dai, X D; Li, J H; Liu, B X

2005-03-17

With the aid of ab initio calculations, an n-body potential of the Ni-Nb system is constructed under the Finnis-Sinclair formalism and the constructed potential is capable of not only reproducing some static physical properties but also revealing the atomistic mechanism of crystal-to-amorphous transition and associated kinetics. With application of the constructed potential, molecular dynamics simulations using the solid solution models reveal that the physical origin of crystal-to-amorphous transition is the crystalline lattice collapsing while the solute atoms are exceeding the critical solid solubilities, which are determined to be 19 atom % Ni and 13 atom % Nb for the Nb- and Ni-based solid solutions, respectively. It follows that an intrinsic glass-forming ability of the Ni-Nb system is within 19-87 atom % Ni, which matches well with that observed in ion beam mixing/solid-state reaction experiments. Simulations using the Nb/Ni/Nb (Ni/Nb/Ni) sandwich models indicate that the amorphous layer at the interfaces grows in a layer-by-layer mode and that, upon dissolving solute atoms, the Ni lattice approaches and exceeds its critical solid solubility faster than the Nb lattice, revealing an asymmetric behavior in growth kinetics. Moreover, an energy diagram is obtained by computing the energetic sequence of the Ni(x)Nb(100)(-)(x) alloy in fcc, bcc, and amorphous structures, respectively, over the entire composition range, and the diagram could serve as a guide for predicting the metastable alloy formation in the Ni-Nb system.

Treatment Seeking and Self-Constructed Explanations of Pain and Pain Management Strategies Among Adolescents with Temporomandibular Disorder Pain.

PubMed

Nilsson, Ing-Marie; Willman, Ania

2016-01-01

To explore adolescents' explanations of their temporomandibular disorder (TMD) pain, their pain management strategies for TMD pain, and their treatment-seeking behavior. One-on-one interviews were conducted with 21 adolescents aged 15 to 19 years who had TMD pain and followed a semistructured interview guide. Subjects were strategically selected from patients referred to an orofacial pain clinic. All participants had been examined and received a pain diagnosis based on the Research Diagnostic Criteria for TMD. The interviews focused on the adolescents' experiences of TMD pain, their strategies for handling pain, and how they seek care. The interviews were recorded, transcribed verbatim, and analyzed using qualitative manifest content analysis. Qualitative manifest content analysis revealed two categories: (1) self-constructed explanations, with three subcategories (situation-based explanatory model, physical/biologic model, and psychological explanatory model); and (2) pain management strategies, with four subcategories (social support, treatment, relaxation/rest, and psychological strategies). Adolescents used physical activities and psychological and pharmacologic treatment to manage pain. Reasons for seeking treatment were to be cured, to obtain an explanation for their pain, and because their symptoms bother others. Adolescents living with TMD pain develop self-constructed explanations and pain management strategies. With access to these descriptions, dentists can be better prepared to have a dialogue with their adolescent patients about their own explanations of pain, the nature of pain, and in which situations the pain appears. Dentists can also explore adolescent patients' pain management strategies and perhaps also suggest new treatment strategies at an earlier stage.

Exploring Formation Models for Ceres Tholi and Montes

NASA Astrophysics Data System (ADS)

Ruesch, O.; Platz, T.; McFadden, L. A.; Hiesinger, H.; Schenk, P.; Sykes, M. V.; Schmidt, B. E.; Buczkowski, D.; Thangjam, G.; Raymond, C. A.; Russell, C. T.

2015-12-01

Dawn Framing Camera (FC) images of Ceres surface revealed tholi and mons, i.e., positive relief features with sub-circular to irregular basal shapes and varying height to diameter ratios and flank slopes. These domes and mounts are tentatively interpreted as volcanic constructs [1]. Alternative formation mechanisms, e.g., uplifting by diapirism or shallow intrusions [e.g., 2], could have also led to the observed features with different geological implications. FC images derived local digital elevation models reveal that the largest dome on Ceres (near Rongo crater) has a ~100 km wide base, concave downward margins with slopes of 10°-20°, a relatively flat top reaching altitudes of ~5 km relative to surrounding, and a summit pit chain of putative endogenic origin. A relevant mons on Ceres is a cone-shaped relief (10°S/316°E) with a ~30x20 km base, reaching a high of ~5 km relative to surroundings. Flank slopes approach a concave upward shape. These constructs are located in a complex geological area having resurfaced units with onlap contacts. Because of the varying morphometries of the reliefs, we explore several physical models of volcanic constructs, e.g., steep-sided dome and shield volcano. Physical models are based on radially spreading viscous gravity currents with a free upper surface [e.g., 3, 4]. Testing formation scenarios will exploit recently developed methods, such as time-variable viscosity and fixed-volume models [5], and constant flow rate models [6]. We aim to provide constraints on viable emplacement mechanisms for the different reliefs. [1] Platz et al. (2015), EPSC abstract 915, vol. 10; [2] Fagents, S.A. (2003), JGR, vol. 108, E12, 5139; [3] Huppert, H. (1982), J. Fluid Mech., vol. 121, pp. 43-58; [4] Lacey et al. (1981), EPSL, vol. 54, pp. 139-143; [5] Glaze et al. (2012), LPSC abstract 1074 ; [6] Glaze et al. (2015), LPSC abstract 1326.

Impact of individual resilience and safety climate on safety performance and psychological stress of construction workers: A case study of the Ontario construction industry.

PubMed

Chen, Yuting; McCabe, Brenda; Hyatt, Douglas

2017-06-01

The construction industry has hit a plateau in terms of safety performance. Safety climate is regarded as a leading indicator of safety performance; however, relatively little safety climate research has been done in the Canadian construction industry. Safety climate may be geographically sensitive, thus it is necessary to examine how the construct of safety climate is defined and used to improve safety performance in different regions. On the other hand, more and more attention has been paid to job related stress in the construction industry. Previous research proposed that individual resilience may be associated with a better safety performance and may help employees manage stress. Unfortunately, few empirical research studies have examined this hypothesis. This paper aims to examine the role of safety climate and individual resilience in safety performance and job stress in the Canadian construction industry. The research was based on 837 surveys collected in Ontario between June 2015 and June 2016. Structural equation modeling (SEM) techniques were used to explore the impact of individual resilience and safety climate on physical safety outcomes and on psychological stress among construction workers. The results show that safety climate not only affected construction workers' safety performance but also indirectly affected their psychological stress. In addition, it was found that individual resilience had a direct negative impact on psychological stress but had no impact on physical safety outcomes. These findings highlight the roles of both organizational and individual factors in individual safety performance and in psychological well-being. Construction organizations need to not only monitor employees' safety performance, but also to assess their employees' psychological well-being. Promoting a positive safety climate together with developing training programs focusing on improving employees' psychological health - especially post-trauma psychological health - can improve the safety performance of an organization. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Earth's magnetosphere modeling and ISO standard

NASA Astrophysics Data System (ADS)

Alexeev, I.

The empirical model developed by Tsyganenko T96 is constructed by minimizing the rms deviation from the large magnetospheric data base Fairfield et al 1994 which contains Earth s magnetospheric magnetic field measurements accumulated during many years The applicability of the T96 model is limited mainly by quiet conditions in the solar wind along the Earth orbit But contrary to the internal planet s field the external magnetospheric magnetic field sources are much more time-dependent A reliable representation of the magnetic field is crucial in the framework of radiation belt modelling especially for disturbed conditions The last version of the Tsyganenko model has been constructed for a geomagnetic storm time interval This version based on the more accurate and physically consistent approach in which each source of the magnetic field would have its own relaxation timescale and a driving function based on an individual best fit combination of the solar wind and IMF parameters The same method has been used previously for paraboloid model construction This method is based on a priori information about the global magnetospheric current systems structure Each current system is included as a separate block module in the magnetospheric model As it was shown by the spacecraft magnetometer data there are three current systems which are the main contributors to the external magnetospheric magnetic field magnetopause currents ring current and tail current sheet Paraboloid model is based on an analytical solution of the Laplace

SketchBio: a scientist's 3D interface for molecular modeling and animation.

PubMed

Waldon, Shawn M; Thompson, Peter M; Hahn, Patrick J; Taylor, Russell M

2014-10-30

Because of the difficulties involved in learning and using 3D modeling and rendering software, many scientists hire programmers or animators to create models and animations. This both slows the discovery process and provides opportunities for miscommunication. Working with multiple collaborators, a tool was developed (based on a set of design goals) to enable them to directly construct models and animations. SketchBio is presented, a tool that incorporates state-of-the-art bimanual interaction and drop shadows to enable rapid construction of molecular structures and animations. It includes three novel features: crystal-by-example, pose-mode physics, and spring-based layout that accelerate operations common in the formation of molecular models. Design decisions and their consequences are presented, including cases where iterative design was required to produce effective approaches. The design decisions, novel features, and inclusion of state-of-the-art techniques enabled SketchBio to meet all of its design goals. These features and decisions can be incorporated into existing and new tools to improve their effectiveness.

Potential of near-infrared spectroscopy for quality evaluation of cattle leather.

PubMed

Braz, Carlos Eduardo M; Jacinto, Manuel Antonio C; Pereira-Filho, Edenir R; Souza, Gilberto B; Nogueira, Ana Rita A

2018-05-09

Models using near-infrared spectroscopy (NIRS) were constructed based on physical-mechanical tests to determine the quality of cattle leather. The following official parameters were used, considering the industry requirements: tensile strength (TS), percentage elongation (%E), tear strength (TT), and double hole tear strength (DHS). Classification models were constructed with the use of k-nearest neighbor (kNN), soft independent modeling of class analogy (SIMCA), and partial least squares-discriminant analysis (PLS-DA). The evaluated figures of merit, accuracy, sensitivity, and specificity presented results between 85% and 93%, and the false alarm rates from 9% to 14%. The model with lowest validation percentage (92%) was kNN, and the highest was PLS-DA (100%). For TS, lower values were obtained, from 52% for kNN and 74% for SIMCA. The other parameters %E, TT, and DHS presented hit rates between 87 and 100%. The abilities of the models were similar, showing they can be used to predict the quality of cattle leather. Copyright © 2018 Elsevier B.V. All rights reserved.

Is Going Beyond Rasch Analysis Necessary to Assess the Construct Validity of a Motor Function Scale?

PubMed

Guillot, Tiffanie; Roche, Sylvain; Rippert, Pascal; Hamroun, Dalil; Iwaz, Jean; Ecochard, René; Vuillerot, Carole

2018-04-03

To examine whether a Rasch analysis is sufficient to establish the construct validity of the Motor Function Measure (MFM) and discuss whether weighting the MFM item scores would improve the MFM construct validity. Observational cross-sectional multicenter study. Twenty-three physical medicine departments, neurology departments, or reference centers for neuromuscular diseases. Patients (N=911) aged 6 to 60 years with Charcot-Marie-Tooth disease (CMT), facioscapulohumeral dystrophy (FSHD), or myotonic dystrophy type 1 (DM1). None. Comparison of the goodness-of-fit of the confirmatory factor analysis (CFA) model vs that of a modified multidimensional Rasch model on MFM item scores in each considered disease. The CFA model showed good fit to the data and significantly better goodness of fit than the modified multidimensional Rasch model regardless of the disease (P<.001). Statistically significant differences in item standardized factor loadings were found between DM1, CMT, and FSHD in only 6 of 32 items (items 6, 27, 2, 7, 9 and 17). For multidimensional scales designed to measure patient abilities in various diseases, a Rasch analysis might not be the most convenient, whereas a CFA is able to establish the scale construct validity and provide weights to adapt the item scores to a specific disease. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Self-Efficacy and the Stages and Processes of Change Associated with Adopting and Maintaining Muscular Fitness-Promoting Behaviors

ERIC Educational Resources Information Center

Cardinal, Bradley J.; Kosma, Maria

2004-01-01

The majority of physical activity initiatives have been directed toward promoting cardiorespiratory fitness and general health. Far less attention has been devoted to encouraging or understanding muscular fitness-promoting behaviors. The purpose of this study was to determine if constructs from the Transtheoretical Model, a contemporary behavior…

Information Measures for Multisensor Systems

DTIC Science & Technology

2013-12-11

permuted to generate spectra that were non- physical but preserved the entropy of the source spectra. Another 1000 spectra were constructed to mimic co...Research Laboratory (NRL) has yielded probabilistic models for spectral data that enable the computation of information measures such as entropy and...22308 Chemical sensing Information theory Spectral data Information entropy Information divergence Mass spectrometry Infrared spectroscopy Multisensor

Relationship of Second-Year College Student Wellness Behaviors to Academic Achievement by Gender, Race/Ethnicity, and Socioeconomic Status

ERIC Educational Resources Information Center

Howell, Cheryl A.

2010-01-01

The purpose of this study was to investigate second-year college student wellness behaviors and their relationship to academic achievement. The ten constructs of wellness within Hettler's model of wellness are physical fitness, nutrition, self-care and safety, environmental wellness, social awareness, emotional awareness and sexuality, emotional…

Developing a Construct-Based Assessment to Examine Students' Analogical Reasoning around Physical Models in Earth Science

ERIC Educational Resources Information Center

Rivet, Ann E.; Kastens, Kim A.

2012-01-01

In recent years, science education has placed increasing importance on learners' mastery of scientific reasoning. This growing emphasis presents a challenge for both developers and users of assessments. We report on our effort around the conceptualization, development, and testing the validity of an assessment of students' ability to reason around…

SNP discovery and chromosome anchoring provide the first physically-anchored hexaploid oat map and reveal synteny with model species

USDA-ARS?s Scientific Manuscript database

For the first time in many years a comprehensive genome map for cultivated oat has been constructed using a combination of single nucleotide polymorphism (SNP) markers and validated with a collection of cytogenetically defined germplasm lines. The markers were able to help distinguish the three geno...

A Multiple Motives Approach to Tobacco Dependence: The Wisconsin Inventory of Smoking Dependence Motives (WISDM-68)

ERIC Educational Resources Information Center

Piper, Megan E.; Piasecki, Thomas M.; Federman, E. Belle; Bolt, Daniel M.; Smith, Stevens S.; Fiore, Michael C.; Baker, Timothy C.

2004-01-01

The dependence construct fills an important explanatory role in motivational accounts of smoking and relapse. Frequently used measures of dependence are either atheoretical or grounded in a unidimensional model of physical dependence. This research creates a multidimensional measure of dependence that is based on theoretically grounded motives for…

Investigation of Mental Models of Turkish Pre-Service Physics Students for the Concept of "Spin"

ERIC Educational Resources Information Center

Özcan, Özgür

2013-01-01

Problem Statement: Difficulties in the learning process usually emerge from the problem of mental representations constructed by students in their interactions with the world. This previous knowledge and these ideas are in contradiction with scientific facts, and are known as misconceptions or alternative ideas. Thus, an analysis of the mental…

Divergent pathways to influence: Cognition and behavior differentially mediate the effects of optimism on physical and mental quality of life in Chinese university students.

PubMed

Ramsay, Jonathan E; Yang, Fang; Pang, Joyce S; Lai, Ching-Man; Ho, Roger Cm; Mak, Kwok-Kei

2015-07-01

Previous research has indicated that both cognitive and behavioral variables mediate the positive effect of optimism on quality of life; yet few attempts have been made to accommodate these constructs into a single explanatory framework. Adopting Fredrickson's broaden-and-build perspective, we examined the relationships between optimism, self-rated health, resilience, exercise, and quality of life in 365 Chinese university students using path analysis. For physical quality of life, a two-stage model, in which the effects of optimism were sequentially mediated by cognitive and behavioral variables, provided the best fit. A one-stage model, with full mediation by cognitive variables, provided the best fit for mental quality of life. This suggests that optimism influences physical and mental quality of life via different pathways. © The Author(s) 2013.

The Utilization and Design of Physical Facilities for the Rehabilitation of Mentally Retarded. Final Project Report.

ERIC Educational Resources Information Center

Bair, Howard V.; Leland, Henry

To investigate the appropriate design and utilization of physical facilities being constructed as a rehabilitation center, a variety of centers was examined. Conclusions were that flexibility in construction of the physical plant, including nonpermanent walls and fixtures was necessary; program planning should be included in architectural…

Constructing high-accuracy intermolecular potential energy surface with multi-dimension Morse/Long-Range model

NASA Astrophysics Data System (ADS)

Zhai, Yu; Li, Hui; Le Roy, Robert J.

2018-04-01

Spectroscopically accurate Potential Energy Surfaces (PESs) are fundamental for explaining and making predictions of the infrared and microwave spectra of van der Waals (vdW) complexes, and the model used for the potential energy function is critically important for providing accurate, robust and portable analytical PESs. The Morse/Long-Range (MLR) model has proved to be one of the most general, flexible and accurate one-dimensional (1D) model potentials, as it has physically meaningful parameters, is flexible, smooth and differentiable everywhere, to all orders and extrapolates sensibly at both long and short ranges. The Multi-Dimensional Morse/Long-Range (mdMLR) potential energy model described herein is based on that 1D MLR model, and has proved to be effective and accurate in the potentiology of various types of vdW complexes. In this paper, we review the current status of development of the mdMLR model and its application to vdW complexes. The future of the mdMLR model is also discussed. This review can serve as a tutorial for the construction of an mdMLR PES.

Theoretical model to explain the problem-solving process in physics

NASA Astrophysics Data System (ADS)

Lopez, Carlos

2011-03-01

This work reports a theoretical model developed with the aim to explain the mental mechanisms of knowledge building during the problem-solving process in physics using a hybrid approach of assimilation- formation of concepts. The model has been termed conceptual chains and represents graphic diagrams of conceptual dependency, which have yielded information about the background knowledge required during the learning process, as well as about the formation of diverse structures that correspond to distinct forms of networking concepts Additionally, the conceptual constructs of the model have been classified according to five types of knowledge. Evidence was found about the influence of these structures, as well as of the distinct types of knowledge about the degree of difficulty of the problems. I want to be grateful to Laureate International Universities, Baltimore M.D., USA, for the financing granted for the accomplishment of this work.

Aspects of effective supersymmetric theories

NASA Astrophysics Data System (ADS)

Tziveloglou, Panteleimon

This work consists of two parts. In the first part we construct the complete extension of the Minimal Supersymmetric Standard Model by higher dimensional effective operators and then study its phenomenology. These operators encapsulate the effects on LHC physics of any kind of new degrees of freedom at the multiTeV scale. The effective analysis includes the case where the multiTeV physics is the supersymmetry breaking sector itself. In that case the appropriate framework is nonlinear supersymmetry. We choose to realize the nonlinear symmetry by the method of constrained superfields. Beyond the new effective couplings, the analysis suggests an interpretation of the 'little hierarchy problem' as an indication of new physics at multiTeV scale. In the second part we explore the power of constrained superfields in extended supersymmetry. It is known that in N = 2 supersymmetry the gauge kinetic function cannot depend on hypermultiplet scalars. However, it is also known that the low energy effective action of a D-brane in an N = 2 supersymmetric bulk includes the DBI action, where the gauge kinetic function does depend on the dilaton. We show how the nonlinearization of the second SUSY (imposed by the presence of the D-brane) opens this possibility, by constructing the global N = 1 linear + 1 nonlinear invariant coupling of a hypermultiplet with a gauge multiplet. The constructed theory enjoys interesting features, including a novel super-Higgs mechanism without gravity.

Constructing an everywhere and locally relevant predictive model of the West-African critical zone

NASA Astrophysics Data System (ADS)

Hector, B.; Cohard, J. M.; Pellarin, T.; Maxwell, R. M.; Cappelaere, B.; Demarty, J.; Grippa, M.; Kergoat, L.; Lebel, T.; Mamadou, O.; Mougin, E.; Panthou, G.; Peugeot, C.; Vandervaere, J. P.; Vischel, T.; Vouillamoz, J. M.

2017-12-01

Considering water resources and hydrologic hazards, West Africa is among the most vulnerable regions to face both climatic (e.g. with the observed intensification of precipitation) and anthropogenic changes. With +3% of demographic rate, the region experiences rapid land use changes and increased pressure on surface and groundwater resources with observed consequences on the hydrological cycle (water table rise result of the sahelian paradox, increase in flood occurrence, etc.) Managing large hydrosystems (such as transboundary aquifers or rivers basins as the Niger river) requires anticipation of such changes. However, the region significantly lacks observations, for constructing and validating critical zone (CZ) models able to predict future hydrologic regime, but also comprises hydrosystems which encompass strong environmental gradients (e.g. geological, climatic, ecological) with highly different dominating hydrological processes. We address these issues by constructing a high resolution (1 km²) regional scale physically-based model using ParFlow-CLM which allows modeling a wide range of processes without prior knowledge on their relative dominance. Our approach combines multiple scale modeling from local to meso and regional scales within the same theoretical framework. Local and meso-scale models are evaluated thanks to the rich AMMA-CATCH CZ observation database which covers 3 supersites with contrasted environments in Benin (Lat.: 9.8°N), Niger (Lat.: 13.3°N) and Mali (Lat.: 15.3°N). At the regional scale the lack of relevant map of soil hydrodynamic parameters is addressed using remote sensing data assimilation. Our first results show the model's ability to reproduce the known dominant hydrological processes (runoff generation, ET, groundwater recharge…) across the major West-African regions and allow us to conduct virtual experiments to explore the impact of global changes on the hydrosystems. This approach is a first step toward the construction of a reference model to study regional CZ sensitivity to global changes and will help to identify prior parameters required and to construct meta-models for deeper investigations of interactions within the CZ.

Different Factor Structures for Women’s Aggression and Victimization Among Women Who Used Aggression Against Male Partners

PubMed Central

Swan, Suzanne C.; Gambone, Laura J.; Van Horn, M. Lee; Snow, David L.; Sullivan, Tami P.

2013-01-01

Theories and measures of women’s aggression in intimate relationships are only beginning to be developed. This study provides a first step in conceptualizing the measurement of women’s aggression by examining how well three widely used measures perform in assessing women’s perpetration of and victimization by aggression in their intimate relationships with men (i.e., the Conflict Tactics Scales 2; Straus, Hamby, & Warren, 2003, the Sexual Experiences Survey; Koss, Gidycz, & Wisniewski, 1987, and the Psychological Maltreatment of Women Inventory; Tolman, 1999). These constructs were examined in a diverse sample of 412 African American, Latina, and White women who had all recently used physical aggression against a male intimate partner. The factor structures and psychometric properties of perpetration and victimization models using these measures were compared. Results indicate that the factor structure of women’s perpetration differs from that of women’s victimization in theoretically meaningful ways. In the victimization model, all factors performed well in contributing to the measurement of the latent victimization construct. In contrast, the perpetration model performed well in assessing women’s physical and psychological aggression, but performed poorly in assessing women’s sexual aggression, coercive control, and jealous monitoring. Findings suggest that the power and control model of intimate partner violence may apply well to women’s victimization, but not as well to their perpetration. PMID:23012348

Soft 3D-Printed Phantom of the Human Kidney with Collecting System.

PubMed

Adams, Fabian; Qiu, Tian; Mark, Andrew; Fritz, Benjamin; Kramer, Lena; Schlager, Daniel; Wetterauer, Ulrich; Miernik, Arkadiusz; Fischer, Peer

2017-04-01

Organ models are used for planning and simulation of operations, developing new surgical instruments, and training purposes. There is a substantial demand for in vitro organ phantoms, especially in urological surgery. Animal models and existing simulator systems poorly mimic the detailed morphology and the physical properties of human organs. In this paper, we report a novel fabrication process to make a human kidney phantom with realistic anatomical structures and physical properties. The detailed anatomical structure was directly acquired from high resolution CT data sets of human cadaveric kidneys. The soft phantoms were constructed using a novel technique that combines 3D wax printing and polymer molding. Anatomical details and material properties of the phantoms were validated in detail by CT scan, ultrasound, and endoscopy. CT reconstruction, ultrasound examination, and endoscopy showed that the designed phantom mimics a real kidney's detailed anatomy and correctly corresponds to the targeted human cadaver's upper urinary tract. Soft materials with a tensile modulus of 0.8-1.5 MPa as well as biocompatible hydrogels were used to mimic human kidney tissues. We developed a method of constructing 3D organ models from medical imaging data using a 3D wax printing and molding process. This method is cost-effective means for obtaining a reproducible and robust model suitable for surgical simulation and training purposes.

Numerical approach to constructing the lunar physical libration: results of the initial stage

NASA Astrophysics Data System (ADS)

Zagidullin, A.; Petrova, N.; Nefediev, Yu.; Usanin, V.; Glushkov, M.

2015-10-01

So called "main problem" it is taken as a model to develop the numerical approach in the theory of lunar physical libration. For the chosen model, there are both a good methodological basis and results obtained at the Kazan University as an outcome of the analytic theory construction. Results of the first stage in numerical approach are presented in this report. Three main limitation are taken to describe the main problem: -independent consideration of orbital and rotational motion of the Moon; - a rigid body model for the lunar body is taken and its dynamical figure is described by inertia ellipsoid, which gives us the mass distribution inside the Moon. - only gravitational interaction with the Earth and the Sun is considered. Development of selenopotential is limited on this stage by the second harmonic only. Inclusion of the 3-rd and 4-th order harmonics is the nearest task for the next stage.The full solution of libration problem consists of removing the below specified limitations: consideration of the fine effects, caused by planet perturbations, by visco-elastic properties of the lunar body, by the presence of a two-layer lunar core, by the Earth obliquity, by ecliptic rotation, if it is taken as a reference plane.

Girls' Bodily Activities in Physical Education How Current Fitness and Sport Discourses Influence Girls' Identity Construction

ERIC Educational Resources Information Center

Walseth, Kristin; Aartun, Iselin; Engelsrud, Gunn

2017-01-01

Girls' identity constructions are influenced by the dominant sport, health and beauty discourses in their society. Recent research indicates that sport and health discourses embedded in physical education (PE) compete for influence. Some of these studies have illustrated how these discourses inform girls' social construction of body ideals and…

Behavioral Self-Regulation and Weight-Related Behaviors in Inner-City Adolescents: A Model of Direct and Indirect Effects

PubMed Central

Isasi, Carmen R.; Wills, Thomas A.

2012-01-01

Background This study examined the association of two distinct self-regulation constructs, effortful control and dysregulation, with weight-related behaviors in adolescents and tested whether these effects were mediated by self-efficacy variables. Methods A school-based survey was conducted with 1771 adolescents from 11 public schools in the Bronx, New York. Self-regulation was assessed by multiple indicators and defined as two latent constructs. Dependent variables included fruit/vegetable intake, intake of snack/junk food, frequency of physical activity, and time spent in sedentary behaviors. Structural equation modeling examined the relation of effortful control and dysregulation to lifestyle behaviors, with self-efficacy variables as possible mediators. Results Study results showed that effortful control had a positive indirect effect on fruit and vegetable intake, mediated by self-efficacy, as well as a direct effect. Effortful control also had a positive indirect effect on physical activity, mediated by self-efficacy. Dysregulation had direct effects on intake of junk food/snacks and time spent in sedentary behaviors. Conclusions These findings indicate that self-regulation characteristics are related to diet and physical activity and that some of these effects are mediated by self-efficacy. Different effects were noted for the two domains of self-regulation. Prevention researchers should consider including self-regulation processes in programs to improve health behaviors in adolescents. PMID:23243551

Exact traveling wave solutions of modified KdV-Zakharov-Kuznetsov equation and viscous Burgers equation.

PubMed

Islam, Md Hamidul; Khan, Kamruzzaman; Akbar, M Ali; Salam, Md Abdus

2014-01-01

Mathematical modeling of many physical systems leads to nonlinear evolution equations because most physical systems are inherently nonlinear in nature. The investigation of traveling wave solutions of nonlinear partial differential equations (NPDEs) plays a significant role in the study of nonlinear physical phenomena. In this article, we construct the traveling wave solutions of modified KDV-ZK equation and viscous Burgers equation by using an enhanced (G '/G) -expansion method. A number of traveling wave solutions in terms of unknown parameters are obtained. Derived traveling wave solutions exhibit solitary waves when special values are given to its unknown parameters. 35C07; 35C08; 35P99.

Ultrahigh-energy cosmic rays: physics and astrophysics at extreme energies.

PubMed

Sigl, G

2001-01-05

The origin of cosmic rays is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed have macroscopic energies up to several 10(20) electron volts and thus provide a probe of physics and astrophysics at energies unattained in laboratory experiments. Theoretical explanations range from astrophysical acceleration of charged particles, to particle physics beyond the established standard model, and processes taking place at the earliest moments of our universe. Distinguishing between these scenarios requires detectors with effective areas in the 1000-square-kilometer range, which are now under construction or in the planning stage. Close connections with gamma-ray and neutrino astrophysics add to the interdisciplinary character of this field.

Distributed and Lumped Parameter Models for the Characterization of High Throughput Bioreactors

PubMed Central

Conoscenti, Gioacchino; Cutrì, Elena; Tuan, Rocky S.; Raimondi, Manuela T.; Gottardi, Riccardo

2016-01-01

Next generation bioreactors are being developed to generate multiple human cell-based tissue analogs within the same fluidic system, to better recapitulate the complexity and interconnection of human physiology [1, 2]. The effective development of these devices requires a solid understanding of their interconnected fluidics, to predict the transport of nutrients and waste through the constructs and improve the design accordingly. In this work, we focus on a specific model of bioreactor, with multiple input/outputs, aimed at generating osteochondral constructs, i.e., a biphasic construct in which one side is cartilaginous in nature, while the other is osseous. We next develop a general computational approach to model the microfluidics of a multi-chamber, interconnected system that may be applied to human-on-chip devices. This objective requires overcoming several challenges at the level of computational modeling. The main one consists of addressing the multi-physics nature of the problem that combines free flow in channels with hindered flow in porous media. Fluid dynamics is also coupled with advection-diffusion-reaction equations that model the transport of biomolecules throughout the system and their interaction with living tissues and C constructs. Ultimately, we aim at providing a predictive approach useful for the general organ-on-chip community. To this end, we have developed a lumped parameter approach that allows us to analyze the behavior of multi-unit bioreactor systems with modest computational effort, provided that the behavior of a single unit can be fully characterized. PMID:27669413

Distributed and Lumped Parameter Models for the Characterization of High Throughput Bioreactors.

PubMed

Iannetti, Laura; D'Urso, Giovanna; Conoscenti, Gioacchino; Cutrì, Elena; Tuan, Rocky S; Raimondi, Manuela T; Gottardi, Riccardo; Zunino, Paolo

Next generation bioreactors are being developed to generate multiple human cell-based tissue analogs within the same fluidic system, to better recapitulate the complexity and interconnection of human physiology [1, 2]. The effective development of these devices requires a solid understanding of their interconnected fluidics, to predict the transport of nutrients and waste through the constructs and improve the design accordingly. In this work, we focus on a specific model of bioreactor, with multiple input/outputs, aimed at generating osteochondral constructs, i.e., a biphasic construct in which one side is cartilaginous in nature, while the other is osseous. We next develop a general computational approach to model the microfluidics of a multi-chamber, interconnected system that may be applied to human-on-chip devices. This objective requires overcoming several challenges at the level of computational modeling. The main one consists of addressing the multi-physics nature of the problem that combines free flow in channels with hindered flow in porous media. Fluid dynamics is also coupled with advection-diffusion-reaction equations that model the transport of biomolecules throughout the system and their interaction with living tissues and C constructs. Ultimately, we aim at providing a predictive approach useful for the general organ-on-chip community. To this end, we have developed a lumped parameter approach that allows us to analyze the behavior of multi-unit bioreactor systems with modest computational effort, provided that the behavior of a single unit can be fully characterized.

Contradictory individualized self-blaming: a cross-sectional study of associations between expectations to managers, coworkers, one-self and risk factors for musculoskeletal disorders among construction workers.

PubMed

Ajslev, Jeppe Zielinski Nguyen; Persson, Roger; Andersen, Lars Louis

2017-01-10

Within work sociology, several studies have addressed construction workers' practices of masculinity, class, economy, safety risks and production. However, few studies have investigated room for agency in relation to bodily pain or musculoskeletal disorders and even fewer have made a quantitative approach. Accordingly, by means of a questionnaire, we examined the association between construction workers' room for agency and physical exertion, bodily and mental fatigue, and lower back pain. A total of 481 Danish construction workers who responded to a multifaceted questionnaire were included. Drawing on previous studies and a Foucauldian inspired concept of agency, agency was quantified through specially crafted questions and examined in relation to established measures on physical exertion, physical and mental fatigue and pain in the lower back. Associations were tested using analyses of variance (general linear models) and controlled for age, gender, job group, lifestyle and depression. When asked about options for agency reducing the burden of work, few workers believed themselves to be prime agents of such practices. When asking about their view on performing alternative agency implying caring for the body, 39-49% expected negative reactions from management, and 20-33% expected negative reactions from colleagues. In contrast, only 13-18% of the participants stated that they would give a negative reception to such alternative practices. Using the expected reception outcomes (positive, neutral, negative) to alternative practices as predictors, the statistical regression analyses showed that negative expectations to management were associated with higher levels of physical exertion 0.62 (95% CI = 0.14-1.09) (scale 0-11), bodily fatigue 0.63 (95% CI = 0.22-1.04), mental fatigue 0.60 (95% CI = 0.07-1.12), and low back pain 0.79 (95% CI = 0.13-1.46) (scales 0-10). In our study, construction workers answered questions about work and MSD. The answers indicated a contradiction between perceived responsibility and room for agency. Based on the study, a number of target areas could fruitfully be addressed in aiming to reduce MSD among construction workers. To change workers' expectances to the reception of lowering work pace if needed to take care of the body, their expectances to the reception of sickness absence as a result of pain, of discussing physical exertion in work and of demanding appropriate technical assistive devices are such examples. Our results emphasize that management plays an important role in this.

Depletion of interstitial oxygen in silicon and the thermal donor model

NASA Technical Reports Server (NTRS)

Borenstein, Jeffrey T.; Singh, Vijay A.; Corbett, James W.

1987-01-01

It is shown here that the experimental results of Newman (1985) and Tan et al. (1986) regarding the loss of oxygen interstitials during 450 C annealing of Czochralski silicon are consistent with the recently proposed model of Borenstein, Peak, and Corbett (1986) for thermal donor formation. Calculations were carried out for TD cores corresponding to O2, O3, O4, and/or O5 clusters. A simple model which attempts to capture the essential physics of the interstitial depletion has been constructed, and is briefly described.

Modeling the Effect of Surface Modification of Gold Nanoparticles Irradiated with 60Co on the Secondary Particles Emission Spectrum

NASA Astrophysics Data System (ADS)

Belousov, A. V.; Morozov, V. N.; Krusanov, G. A.; Kolyvanova, M. A.; Chernyaev, A. P.; Shtil, A. A.

2018-03-01

The Monte Carlo method (computer simulation) is used to construct a physical model of secondary particles emission induced by the simulated irradiation of a gold nanoparticle with 60Co. It is demonstrated that the modification of the nanoparticle surface with polyethylene glycol affects the spectrum of secondary electrons produced in a nanoparticle and leaving it and its shell. The model takes into account the size and the chemical composition of the shell and provides an opportunity to design antitumor radiosensitizers based on gold nanoparticles.

Offshore marine constructions as propagators of moon jellyfish dispersal

NASA Astrophysics Data System (ADS)

Vodopivec, Martin; Peliz, Álvaro J.; Malej, Alenka

2017-08-01

We have studied the influence of offshore marine constructions on the moon jellyfish population in the Adriatic sea, where the newly set up substrates enable the formation of a new population based in the formerly unpopulated open waters. Our five-year long computer simulation uses a high resolution coupled bio-physical individual-based model to track the dispersal of the offspring from subpopulations originating from offshore and shore-based sources. According to our study, the platforms enhance connectivity between subpopulations of jellyfish polyps, help sustain existing shore-based subpopulations, contribute to jellyfish blooms in some areas, and play an important role in establishing connection with the rest of the Mediterranean, in addition to representing substantial amounts of available substrate. This is an aspect that is usually overlooked when evaluating the ecological impact of existing and future wind farms, oil and gas platforms, etc. Our approach could serve as a role model in future studies of ecological impacts of planned offshore constructions.

Investigating the multi-causal and complex nature of the accident causal influence of construction project features.

PubMed

Manu, Patrick A; Ankrah, Nii A; Proverbs, David G; Suresh, Subashini

2012-09-01

Construction project features (CPFs) are organisational, physical and operational attributes that characterise construction projects. Although previous studies have examined the accident causal influence of CPFs, the multi-causal attribute of this causal phenomenon still remain elusive and thus requires further investigation. Aiming to shed light on this facet of the accident causal phenomenon of CPFs, this study examines relevant literature and crystallises the attained insight of the multi-causal attribute by a graphical model which is subsequently operationalised by a derived mathematical risk expression that offers a systematic approach for evaluating the potential of CPFs to cause harm and consequently their health and safety (H&S) risk implications. The graphical model and the risk expression put forth by the study thus advance current understanding of the accident causal phenomenon of CPFs and they present an opportunity for project participants to manage the H&S risk associated with CPFs from the early stages of project procurement. Copyright © 2011 Elsevier Ltd. All rights reserved.

Model-assisted probability of detection of flaws in aluminum blocks using polynomial chaos expansions

NASA Astrophysics Data System (ADS)

Du, Xiaosong; Leifsson, Leifur; Grandin, Robert; Meeker, William; Roberts, Ronald; Song, Jiming

2018-04-01

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination with model-assisted POD (MAPOD) methods. With the development of advanced physics-based methods, such as ultrasonic NDT testing, the empirical information, needed for POD methods, can be reduced. However, performing accurate numerical simulations can be prohibitively time-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the random input variables through the physics-based simulation model to obtain the joint probability distribution of the output. The POD curves are then generated based on those results. Here, the stochastic surrogates are constructed using non-intrusive polynomial chaos (NIPC) expansions. In particular, the NIPC methods used are the quadrature, ordinary least-squares (OLS), and least-angle regression sparse (LARS) techniques. The proposed approach is demonstrated on the ultrasonic testing simulation of a flat bottom hole flaw in an aluminum block. The results show that the stochastic surrogates have at least two orders of magnitude faster convergence on the statistics than direct Monte Carlo sampling (MCS). Moreover, the evaluation of the stochastic surrogate models is over three orders of magnitude faster than the underlying simulation model for this case, which is the UTSim2 model.

Assessment of Cognitively Stimulating Activity in a Spanish Population.

PubMed

Morales Ortiz, Manuel; Fernández, Aaron

2018-05-01

Theoretical models of active ageing and cognitive reserve emphasize the importance of leading an active life to delay age-related cognitive deterioration and maintain good levels of well-being and personal satisfaction in the elderly. The objective of this research was to construct a scale to measure cognitively stimulating activities (CSA) in the Spanish language. The sample consisted of a total of 453 older persons. The scale was constructed from a list of 28 items and validated using structural equation models. The scale obtained showed a negative correlation with age and a positive correlation with education and physical activity. Using hierarchical regression models, CSAs were found to have a significant effect on attention when controlling for the effect of age and education. Likewise, a significant interaction between age and CSA was found on the measure of episodic memory. The validated CSA scale will enable the relationships between changes in cognitive functions and stimulating activities to be studied.

Equilibrium stability of a cylindrical body subject to the internal structure of the material and inelastic behaviour of the completely compressed matrix

NASA Astrophysics Data System (ADS)

Gotsev, D. V.; Perunov, N. S.; Sviridova, E. N.

2018-03-01

The mathematical model describing the stress-strain state of a cylindrical body under the uniform radial compression effect is constructed. The model of the material is the porous medium model. The compressed skeleton of the porous medium possesses hardening elastic-plastic properties. Deforming of the porous medium under the specified compressive loads is divided into two stages: elastic deforming of the porous medium and further elastic-plastic deforming of the material with completely compressed matrix. The analytical relations that define the fields of stress and displacement at each stage of the deforming are obtained. The influence of the porosity and other physical, mechanical and geometric parameters of the construction on the size of the plastic zone is evaluated. The question of the ground state equilibrium instability is investigated within the framework of the three-dimensional linearized relationships of the stability theory of deformed bodies.

Cylindrically symmetric cosmological model of the universe in modified gravity

NASA Astrophysics Data System (ADS)

Mishra, B.; Vadrevu, Samhita

2017-02-01

In this paper, we have constructed the cosmological models of the universe in a cylindrically symmetric space time in two classes of f(R,T) gravity (Harko et al. in Phys. Rev. D 84:024020, 2011). We have discussed two cases: one in the linear form and the other in the quadratic form of R. The matter is considered to be in the form of perfect fluid. It is observed that in the first case, the pressure and energy density remain the same, which reduces to a Zeldovich fluid. In the second case we have studied the quadratic function of f(R,T) gravity in the form f(R)=λ(R+R2) and f(T)=λ T. In the second case the pressure is in the negative domain and the energy density is in the positive domain, which confirms that the equation of state parameter is negative. The physical properties of the constructed models are studied.

No-scale inflation

NASA Astrophysics Data System (ADS)

Ellis, John; Garcia, Marcos A. G.; Nanopoulos, Dimitri V.; Olive, Keith A.

2016-05-01

Supersymmetry is the most natural framework for physics above the TeV scale, and the corresponding framework for early-Universe cosmology, including inflation, is supergravity. No-scale supergravity emerges from generic string compactifications and yields a non-negative potential, and is therefore a plausible framework for constructing models of inflation. No-scale inflation yields naturally predictions similar to those of the Starobinsky model based on R+{R}2 gravity, with a tilted spectrum of scalar perturbations: {n}s∼ 0.96, and small values of the tensor-to-scalar perturbation ratio r\\lt 0.1, as favoured by Planck and other data on the cosmic microwave background (CMB). Detailed measurements of the CMB may provide insights into the embedding of inflation within string theory as well as its links to collider physics.

Current algebra, statistical mechanics and quantum models

NASA Astrophysics Data System (ADS)

Vilela Mendes, R.

2017-11-01

Results obtained in the past for free boson systems at zero and nonzero temperatures are revisited to clarify the physical meaning of current algebra reducible functionals which are associated to systems with density fluctuations, leading to observable effects on phase transitions. To use current algebra as a tool for the formulation of quantum statistical mechanics amounts to the construction of unitary representations of diffeomorphism groups. Two mathematical equivalent procedures exist for this purpose. One searches for quasi-invariant measures on configuration spaces, the other for a cyclic vector in Hilbert space. Here, one argues that the second approach is closer to the physical intuition when modelling complex systems. An example of application of the current algebra methodology to the pairing phenomenon in two-dimensional fermion systems is discussed.

Spectral Analysis and Experimental Modeling of Ice Accretion Roughness

NASA Technical Reports Server (NTRS)

Orr, D. J.; Breuer, K. S.; Torres, B. E.; Hansman, R. J., Jr.

1996-01-01

A self-consistent scheme for relating wind tunnel ice accretion roughness to the resulting enhancement of heat transfer is described. First, a spectral technique of quantitative analysis of early ice roughness images is reviewed. The image processing scheme uses a spectral estimation technique (SET) which extracts physically descriptive parameters by comparing scan lines from the experimentally-obtained accretion images to a prescribed test function. Analysis using this technique for both streamwise and spanwise directions of data from the NASA Lewis Icing Research Tunnel (IRT) are presented. An experimental technique is then presented for constructing physical roughness models suitable for wind tunnel testing that match the SET parameters extracted from the IRT images. The icing castings and modeled roughness are tested for enhancement of boundary layer heat transfer using infrared techniques in a "dry" wind tunnel.

Low-rank separated representation surrogates of high-dimensional stochastic functions: Application in Bayesian inference

NASA Astrophysics Data System (ADS)

Validi, AbdoulAhad

2014-03-01

This study introduces a non-intrusive approach in the context of low-rank separated representation to construct a surrogate of high-dimensional stochastic functions, e.g., PDEs/ODEs, in order to decrease the computational cost of Markov Chain Monte Carlo simulations in Bayesian inference. The surrogate model is constructed via a regularized alternative least-square regression with Tikhonov regularization using a roughening matrix computing the gradient of the solution, in conjunction with a perturbation-based error indicator to detect optimal model complexities. The model approximates a vector of a continuous solution at discrete values of a physical variable. The required number of random realizations to achieve a successful approximation linearly depends on the function dimensionality. The computational cost of the model construction is quadratic in the number of random inputs, which potentially tackles the curse of dimensionality in high-dimensional stochastic functions. Furthermore, this vector-valued separated representation-based model, in comparison to the available scalar-valued case, leads to a significant reduction in the cost of approximation by an order of magnitude equal to the vector size. The performance of the method is studied through its application to three numerical examples including a 41-dimensional elliptic PDE and a 21-dimensional cavity flow.

Design and construction of an impulse turbine

NASA Astrophysics Data System (ADS)

Hernández, E.

2013-11-01

Impulse turbine has been constructed to be used in the program of Hydraulic Machines, Faculty of Mechanical Engineering at the Universidad Pontificia Bolivariana, sede Bucaramanga. For construction of the impulse turbine (Pelton) detailed plans were drawn up taking into account the design and implementation of the fundamental equations of hydraulic turbomachinery. From the experimental data found maximum mechanical efficiency of 0.6 ± 0.03 for a water flow of 2.1 l/s. The maximum overall efficiency was 0.23 ± 0.02 for a water flow of 0.83 l/s. The design parameter used was a power of 1 kW, as flow regulator built a needle type regulator, which performed well, the model of the bucket or vane is built on a machine type CNC (Computer Numerical Control). For the construction of the impeller and blades was used aluminium because of chemical and physical characteristics and the casing was manufactured in acrylic.

Defining the student burnout construct: a structural analysis from three burnout inventories.

PubMed

Maroco, João; Campos, Juliana Alvares Duarte Bonini

2012-12-01

College student burnout has been assessed mainly with the Maslach burnout inventory (MBI). However, the construct's definition and measurement with MBI has drawn several criticisms and new inventories have been suggested for the evaluation of the syndrome. A redefinition of the construct of student burnout is proposed by means of a structural equation model, reflecting burnout as a second order factor defined by factors from the MBI-student survey (MBI-SS); the Copenhagen burnout inventory-student survey (CBI-SS) and the Oldenburg burnout inventory-student survey (OLBI-SS). Standardized regression weights from Burnout to Exhaustion and Cynicism from the MBI-SS scale, personal burnout and studies related burnout from the CBI, and exhaustion and disengagement from OLBI, show that these factors are strong manifestations of students' burnout. For college students, the burnout construct is best defined by two dimensions described as "physical and psychological exhaustion" and "cynicism and disengagement".

Predicting Physical Activity-Related Outcomes in Overweight and Obese Adults: A Health Action Process Approach.

PubMed

Hattar, Anne; Pal, Sebely; Hagger, Martin S

2016-03-01

We tested the adequacy of a model based on the Health Action Process Approach (HAPA) in predicting changes in psychological, body composition, and cardiovascular risk outcomes with respect to physical activity participation in overweight and obese adults. Measures of HAPA constructs (action and maintenance self-efficacy, outcome expectancies, action planning, risk perceptions, intentions, behaviour), psychological outcomes (quality of life, depression, anxiety, stress symptoms), body composition variables (body weight, body fat mass), cardiovascular risk measures (total cholesterol, low density lipoprotein), and self-reported physical activity behaviour were administered to participants (N = 74) at baseline, and 6 and 12 weeks later. Data were analysed using variance-based structural equation modelling with residualised change scores for HAPA variables. The model revealed effects of action self-efficacy and outcome expectancies on physical activity intentions, action self-efficacy on maintenance self-efficacy, and maintenance self-efficacy and intentions on action planning. Intention predicted psychological and body composition outcomes indirectly through physical activity behaviour. Action planning was a direct predictor of psychological, cardiovascular, and body composition outcomes. Data supported HAPA hypotheses in relation to intentions and behaviour, but not the role of action planning as a mediator of the intention-behaviour relationship. Action planning predicted outcomes independent of intentions and behaviour. © 2016 The International Association of Applied Psychology.

Construction of a quartz spherical analyzer: application to high-resolution analysis of the Ni Kα emission spectrum

DOE PAGES

Honnicke, Marcelo Goncalves; Bianco, Leonardo M.; Ceppi, Sergio A.; ...

2016-08-10

The construction and characterization of a focusing X-ray spherical analyzer based on α-quartz 4more » $$\\overline{4}$$04 are presented. For this study, the performance of the analyzer was demonstrated by applying it to a high-resolution X-ray spectroscopy study of theKα 1,2emission spectrum of Ni. An analytical representation based on physical grounds was assumed to model the shape of the X-ray emission lines. Satellite structures assigned to 3dspectator hole transitions were resolved and determined as well as their relative contribution to the emission spectrum. The present results on 1s -13d -1shake probabilities support a recently proposed calculation framework based on a multi-configuration atomic model.« less

Construction of a quartz spherical analyzer: application to high-resolution analysis of the Ni Kα emission spectrum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Honnicke, Marcelo Goncalves; Bianco, Leonardo M.; Ceppi, Sergio A.

The construction and characterization of a focusing X-ray spherical analyzer based on α-quartz 4more » $$\\overline{4}$$04 are presented. For this study, the performance of the analyzer was demonstrated by applying it to a high-resolution X-ray spectroscopy study of theKα 1,2emission spectrum of Ni. An analytical representation based on physical grounds was assumed to model the shape of the X-ray emission lines. Satellite structures assigned to 3dspectator hole transitions were resolved and determined as well as their relative contribution to the emission spectrum. The present results on 1s -13d -1shake probabilities support a recently proposed calculation framework based on a multi-configuration atomic model.« less