Raykov, Tenko; Marcoulides, George A
2016-04-01
The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. It is pointed out that popular item response models can be directly obtained from classical test theory-based models by accounting for the discrete nature of the observed items. Two distinct observational equivalence approaches are outlined that render the item response models from corresponding classical test theory-based models, and can each be used to obtain the former from the latter models. Similarly, classical test theory models can be furnished using the reverse application of either of those approaches from corresponding item response models.
ERIC Educational Resources Information Center
Fukuhara, Hirotaka; Kamata, Akihito
2011-01-01
A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…
ERIC Educational Resources Information Center
Raykov, Tenko; Marcoulides, George A.
2016-01-01
The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. It is pointed out that popular item response models can be directly obtained from classical test theory-based models by accounting for the discrete…
ERIC Educational Resources Information Center
Li, Feifei
2017-01-01
An information-correction method for testlet-based tests is introduced. This method takes advantage of both generalizability theory (GT) and item response theory (IRT). The measurement error for the examinee proficiency parameter is often underestimated when a unidimensional conditional-independence IRT model is specified for a testlet dataset. By…
An Extension of IRT-Based Equating to the Dichotomous Testlet Response Theory Model
ERIC Educational Resources Information Center
Tao, Wei; Cao, Yi
2016-01-01
Current procedures for equating number-correct scores using traditional item response theory (IRT) methods assume local independence. However, when tests are constructed using testlets, one concern is the violation of the local item independence assumption. The testlet response theory (TRT) model is one way to accommodate local item dependence.…
ERIC Educational Resources Information Center
Flowers, Claudia P.; Raju, Nambury S.; Oshima, T. C.
Current interest in the assessment of measurement equivalence emphasizes two methods of analysis, linear, and nonlinear procedures. This study simulated data using the graded response model to examine the performance of linear (confirmatory factor analysis or CFA) and nonlinear (item-response-theory-based differential item function or IRT-Based…
Trenholm, Susan; Ferlie, Ewan
2013-09-01
We employ complexity theory to analyse the English National Health Service (NHS)'s organisational response to resurgent tuberculosis across London. Tennison (2002) suggests that complexity theory could fruitfully explore a healthcare system's response to this complex and emergent phenomenon: we explore this claim here. We also bring in established New Public Management principles to enhance our empirical analysis, which is based on data collected between late 2009 and mid-2011. We find that the operation of complexity theory based features, especially self-organisation, are significantly impacted by the macro context of a New Public Management-based regime which values control, measurement and risk management more than innovation, flexibility and lateral system building. We finally explore limitations and suggest perspectives for further research. Copyright © 2012 Elsevier Ltd. All rights reserved.
Applying Item Response Theory Methods to Design a Learning Progression-Based Science Assessment
ERIC Educational Resources Information Center
Chen, Jing
2012-01-01
Learning progressions are used to describe how students' understanding of a topic progresses over time and to classify the progress of students into steps or levels. This study applies Item Response Theory (IRT) based methods to investigate how to design learning progression-based science assessments. The research questions of this study are: (1)…
ERIC Educational Resources Information Center
Fu, Jianbin
2016-01-01
The multidimensional item response theory (MIRT) models with covariates proposed by Haberman and implemented in the "mirt" program provide a flexible way to analyze data based on item response theory. In this report, we discuss applications of the MIRT models with covariates to longitudinal test data to measure skill differences at the…
Sense of Community, a Theory Not a Value: A Response to Nowell and Boyd
ERIC Educational Resources Information Center
McMillan, David W.
2011-01-01
This is a response to the Nowell and Boyd (2010) article printed in this journal titled: Viewing Community as Responsibility as Well as Resource: Deconstructing the Theoretical Roots of Psychological Sense of Community. In that article, they argued that the McMillan theory of Sense of Community is a simplistic, needs-based theory that excludes…
NASA Astrophysics Data System (ADS)
Yin, Shengwen; Yu, Dejie; Yin, Hui; Lü, Hui; Xia, Baizhan
2017-09-01
Considering the epistemic uncertainties within the hybrid Finite Element/Statistical Energy Analysis (FE/SEA) model when it is used for the response analysis of built-up systems in the mid-frequency range, the hybrid Evidence Theory-based Finite Element/Statistical Energy Analysis (ETFE/SEA) model is established by introducing the evidence theory. Based on the hybrid ETFE/SEA model and the sub-interval perturbation technique, the hybrid Sub-interval Perturbation and Evidence Theory-based Finite Element/Statistical Energy Analysis (SIP-ETFE/SEA) approach is proposed. In the hybrid ETFE/SEA model, the uncertainty in the SEA subsystem is modeled by a non-parametric ensemble, while the uncertainty in the FE subsystem is described by the focal element and basic probability assignment (BPA), and dealt with evidence theory. Within the hybrid SIP-ETFE/SEA approach, the mid-frequency response of interest, such as the ensemble average of the energy response and the cross-spectrum response, is calculated analytically by using the conventional hybrid FE/SEA method. Inspired by the probability theory, the intervals of the mean value, variance and cumulative distribution are used to describe the distribution characteristics of mid-frequency responses of built-up systems with epistemic uncertainties. In order to alleviate the computational burdens for the extreme value analysis, the sub-interval perturbation technique based on the first-order Taylor series expansion is used in ETFE/SEA model to acquire the lower and upper bounds of the mid-frequency responses over each focal element. Three numerical examples are given to illustrate the feasibility and effectiveness of the proposed method.
NASA Technical Reports Server (NTRS)
Chamis, C. C.; Lark, R. F.; Sinclair, J. H.
1977-01-01
An integrated theory is developed for predicting the hydrothermomechanical (HDTM) response of fiber composite components. The integrated theory is based on a combined theoretical and experimental investigation. In addition to predicting the HDTM response of components, the theory is structured to assess the combined hydrothermal effects on the mechanical properties of unidirectional composites loaded along the material axis and off-axis, and those of angleplied laminates. The theory developed predicts values which are in good agreement with measured data at the micromechanics, macromechanics, laminate analysis and structural analysis levels.
Implementation of an Improved Adaptive Testing Theory
ERIC Educational Resources Information Center
Al-A'ali, Mansoor
2007-01-01
Computer adaptive testing is the study of scoring tests and questions based on assumptions concerning the mathematical relationship between examinees' ability and the examinees' responses. Adaptive student tests, which are based on item response theory (IRT), have many advantages over conventional tests. We use the least square method, a…
NASA Astrophysics Data System (ADS)
Natarajan, Sundararajan
2014-12-01
The main objectives of the paper are to (1) present an overview of nonlocal integral elasticity and Aifantis gradient elasticity theory and (2) discuss the application of partition of unity methods to study the response of low-dimensional structures. We present different choices of approximation functions for gradient elasticity, namely Lagrange intepolants, moving least-squares approximants and non-uniform rational B-splines. Next, we employ these approximation functions to study the response of nanobeams based on Euler-Bernoulli and Timoshenko theories as well as to study nanoplates based on first-order shear deformation theory. The response of nanobeams and nanoplates is studied using Eringen's nonlocal elasticity theory. The influence of the nonlocal parameter, the beam and the plate aspect ratio and the boundary conditions on the global response is numerically studied. The influence of a crack on the axial vibration and buckling characteristics of nanobeams is also numerically studied.
Comparison of Reliability Measures under Factor Analysis and Item Response Theory
ERIC Educational Resources Information Center
Cheng, Ying; Yuan, Ke-Hai; Liu, Cheng
2012-01-01
Reliability of test scores is one of the most pervasive psychometric concepts in measurement. Reliability coefficients based on a unifactor model for continuous indicators include maximal reliability rho and an unweighted sum score-based omega, among many others. With increasing popularity of item response theory, a parallel reliability measure pi…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bowman, David N.; Asher, Jason C.; Fischer, Sean A.
2017-01-01
Threemeso-substituted tetrapyridyl porphyrins (free base, Ni(ii), and Cu(ii)) were investigated for their optical limiting (OL) capabilities using real-time (RT-), linear-response (LR-), and quadratic-response (QR-) time-dependent density functional theory (TDDFT) methods.
ERIC Educational Resources Information Center
Woods, Carol M.; Thissen, David
2006-01-01
The purpose of this paper is to introduce a new method for fitting item response theory models with the latent population distribution estimated from the data using splines. A spline-based density estimation system provides a flexible alternative to existing procedures that use a normal distribution, or a different functional form, for the…
Two Prophecy Formulas for Assessing the Reliability of Item Response Theory-Based Ability Estimates
ERIC Educational Resources Information Center
Raju, Nambury S.; Oshima, T.C.
2005-01-01
Two new prophecy formulas for estimating item response theory (IRT)-based reliability of a shortened or lengthened test are proposed. Some of the relationships between the two formulas, one of which is identical to the well-known Spearman-Brown prophecy formula, are examined and illustrated. The major assumptions underlying these formulas are…
Cultural theories of nursing responsive to human needs and values.
Kikuchi, June F
2005-01-01
To present an alternative to the recent proposal that the extant theories of nursing be replaced with culture-specific theories of nursing in order to have theories of nursing that are culturally responsive. A philosophical analysis of the implications for nursing practice of adopting the proposal serves as the basis for recommending a different philosophically based theoretical solution. Anticipated probable objections to that recommendation are considered. Culture-specific theories of nursing might allow nurses to be culturally sensitive. However, because nurses must be humanly responsive to the needs of people as human beings and not just as cultural beings, cultural theories of nursing should be developed within the precepts of a transcultural theory of nursing grounded in a conception of objective human needs and values.
A Multidimensional Ideal Point Item Response Theory Model for Binary Data
ERIC Educational Resources Information Center
Maydeu-Olivares, Albert; Hernandez, Adolfo; McDonald, Roderick P.
2006-01-01
We introduce a multidimensional item response theory (IRT) model for binary data based on a proximity response mechanism. Under the model, a respondent at the mode of the item response function (IRF) endorses the item with probability one. The mode of the IRF is the ideal point, or in the multidimensional case, an ideal hyperplane. The model…
ERIC Educational Resources Information Center
Makransky, Guido; Dale, Philip S.; Havmose, Philip; Bleses, Dorthe
2016-01-01
Purpose: This study investigated the feasibility and potential validity of an item response theory (IRT)-based computerized adaptive testing (CAT) version of the MacArthur-Bates Communicative Development Inventory: Words & Sentences (CDI:WS; Fenson et al., 2007) vocabulary checklist, with the objective of reducing length while maintaining…
Two Approaches to Estimation of Classification Accuracy Rate under Item Response Theory
ERIC Educational Resources Information Center
Lathrop, Quinn N.; Cheng, Ying
2013-01-01
Within the framework of item response theory (IRT), there are two recent lines of work on the estimation of classification accuracy (CA) rate. One approach estimates CA when decisions are made based on total sum scores, the other based on latent trait estimates. The former is referred to as the Lee approach, and the latter, the Rudner approach,…
ERIC Educational Resources Information Center
Atkinson, Becky M.
2012-01-01
The study reported in this article examines how teachers read and respond to their students' Stanford Achievement Test 10 (SAT 10) scores with the goal of investigating the assumption that data-based teaching practice is more "objective" and less susceptible to divergent teacher interpretation. The study uses reader response theory to…
The effect of stimulus strength on the speed and accuracy of a perceptual decision.
Palmer, John; Huk, Alexander C; Shadlen, Michael N
2005-05-02
Both the speed and the accuracy of a perceptual judgment depend on the strength of the sensory stimulation. When stimulus strength is high, accuracy is high and response time is fast; when stimulus strength is low, accuracy is low and response time is slow. Although the psychometric function is well established as a tool for analyzing the relationship between accuracy and stimulus strength, the corresponding chronometric function for the relationship between response time and stimulus strength has not received as much consideration. In this article, we describe a theory of perceptual decision making based on a diffusion model. In it, a decision is based on the additive accumulation of sensory evidence over time to a bound. Combined with simple scaling assumptions, the proportional-rate and power-rate diffusion models predict simple analytic expressions for both the chronometric and psychometric functions. In a series of psychophysical experiments, we show that this theory accounts for response time and accuracy as a function of both stimulus strength and speed-accuracy instructions. In particular, the results demonstrate a close coupling between response time and accuracy. The theory is also shown to subsume the predictions of Piéron's Law, a power function dependence of response time on stimulus strength. The theory's analytic chronometric function allows one to extend theories of accuracy to response time.
Item response theory scoring and the detection of curvilinear relationships.
Carter, Nathan T; Dalal, Dev K; Guan, Li; LoPilato, Alexander C; Withrow, Scott A
2017-03-01
Psychologists are increasingly positing theories of behavior that suggest psychological constructs are curvilinearly related to outcomes. However, results from empirical tests for such curvilinear relations have been mixed. We propose that correctly identifying the response process underlying responses to measures is important for the accuracy of these tests. Indeed, past research has indicated that item responses to many self-report measures follow an ideal point response process-wherein respondents agree only to items that reflect their own standing on the measured variable-as opposed to a dominance process, wherein stronger agreement, regardless of item content, is always indicative of higher standing on the construct. We test whether item response theory (IRT) scoring appropriate for the underlying response process to self-report measures results in more accurate tests for curvilinearity. In 2 simulation studies, we show that, regardless of the underlying response process used to generate the data, using the traditional sum-score generally results in high Type 1 error rates or low power for detecting curvilinearity, depending on the distribution of item locations. With few exceptions, appropriate power and Type 1 error rates are achieved when dominance-based and ideal point-based IRT scoring are correctly used to score dominance and ideal point response data, respectively. We conclude that (a) researchers should be theory-guided when hypothesizing and testing for curvilinear relations; (b) correctly identifying whether responses follow an ideal point versus dominance process, particularly when items are not extreme is critical; and (c) IRT model-based scoring is crucial for accurate tests of curvilinearity. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Model-based predictions for dopamine.
Langdon, Angela J; Sharpe, Melissa J; Schoenbaum, Geoffrey; Niv, Yael
2018-04-01
Phasic dopamine responses are thought to encode a prediction-error signal consistent with model-free reinforcement learning theories. However, a number of recent findings highlight the influence of model-based computations on dopamine responses, and suggest that dopamine prediction errors reflect more dimensions of an expected outcome than scalar reward value. Here, we review a selection of these recent results and discuss the implications and complications of model-based predictions for computational theories of dopamine and learning. Copyright © 2017. Published by Elsevier Ltd.
ERIC Educational Resources Information Center
Alarcón-del-Amo, María-del-Carmen; Casablancas-Segura, Carme; Llonch, Joan
2016-01-01
This study, based on institutional theory, dynamic capabilities, and stakeholder theory, investigates the relationships between the antecedents of responsive and proactive stakeholder orientation and their consequences in the public university context. The results obtained mainly stress that the mimetic effect of copying successful university…
Item Response Theory Analyses of the Parent and Teacher Ratings of the DSM-IV ADHD Rating Scale
ERIC Educational Resources Information Center
Gomez, Rapson
2008-01-01
The graded response model (GRM), which is based on item response theory (IRT), was used to evaluate the psychometric properties of the inattention and hyperactivity/impulsivity symptoms in an ADHD rating scale. To accomplish this, parents and teachers completed the DSM-IV ADHD Rating Scale (DARS; Gomez et al., "Journal of Child Psychology and…
Cutrona, Carolyn E; Russell, Daniel W
2017-02-01
Adult attachment theory provides guidance for providing optimal social support in intimate relationships. According to attachment theory, facilitating autonomy (secure base support) sometimes is more important than providing nurturance (safe haven support). In addition, it is important that couples celebrate one another's triumphs and successes (another form of secure base support). A key construct that explains the development of attachment is responsiveness to the individual's needs. Support that is delivered in a responsive manner (i.e., that leads the individual to feel understood, validated, and cared for) is more likely to enhance the relationship and less likely to damage self-esteem than assistance that is not responsive. A responsive exchange is more likely if emotion dysregulation can be prevented. Attachment theory offers explanations for why people vary in their effectiveness at emotion regulation. Appropriate emotion regulation is more likely if disclosures of current difficulties can be made in a way that is not defensive or accusatory, an ability that varies as a function of attachment orientation. Attachment theory also offers guidance regarding the optimal forms of social support for specific individuals. All these insights from adult attachment theory can be integrated into interventions to help couples become more effective support providers. Copyright © 2016 Elsevier Ltd. All rights reserved.
Concepts as Semantic Pointers: A Framework and Computational Model
ERIC Educational Resources Information Center
Blouw, Peter; Solodkin, Eugene; Thagard, Paul; Eliasmith, Chris
2016-01-01
The reconciliation of theories of concepts based on prototypes, exemplars, and theory-like structures is a longstanding problem in cognitive science. In response to this problem, researchers have recently tended to adopt either hybrid theories that combine various kinds of representational structure, or eliminative theories that replace concepts…
General response formula and application to topological insulator in quantum open system.
Shen, H Z; Qin, M; Shao, X Q; Yi, X X
2015-11-01
It is well-known that the quantum linear response theory is based on the first-order perturbation theory for a system in thermal equilibrium. Hence, this theory breaks down when the system is in a steady state far from thermal equilibrium and the response up to higher order in perturbation is not negligible. In this paper, we develop a nonlinear response theory for such quantum open system. We first formulate this theory in terms of general susceptibility, after which we apply it to the derivation of Hall conductance for open system at finite temperature. As an example, the Hall conductance of the two-band model is derived. Then we calculate the Hall conductance for a two-dimensional ferromagnetic electron gas and a two-dimensional lattice model. The calculations show that the transition points of topological phase are robust against the environment. Our results provide a promising platform for the coherent manipulation of the nonlinear response in quantum open system, which has potential applications for quantum information processing and statistical physics.
Peri, Tuvia; Gofman, Mordechai; Tal, Shahar; Tuval-Mashiach, Rivka
2015-01-01
Exposure to the trauma memory is the common denominator of most evidence-based interventions for posttraumatic stress disorder (PTSD). Although exposure-based therapies aim to change associative learning networks and negative cognitions related to the trauma memory, emotional interactions between patient and therapist have not been thoroughly considered in past evaluations of exposure-based therapy. This work focuses on recent discoveries of the mirror-neuron system and the theory of embodied simulation (ES). These conceptualizations may add a new perspective to our understanding of change processes in exposure-based treatments for PTSD patients. It is proposed that during exposure to trauma memories, emotional responses of the patient are transferred to the therapist through ES and then mirrored back to the patient in a modulated way. This process helps to alleviate the patient's sense of loneliness and enhances his or her ability to exert control over painful, trauma-related emotional responses. ES processes may enhance the integration of clinical insights originating in psychoanalytic theories-such as holding, containment, projective identification, and emotional attunement-with cognitive behavioral theories of learning processes in the alleviation of painful emotional responses aroused by trauma memories. These processes are demonstrated through a clinical vignette from an exposure-based therapy with a trauma survivor. Possible clinical implications for the importance of face-to-face relationships during exposure-based therapy are discussed.
Interpretation of the Rasch Ability and Difficulty Scales for Educational Purposes.
ERIC Educational Resources Information Center
Woodcock, Richard W.
Though many test developers have utilized item response theory in their work, few have taken advantage of the potential of item response theory for providing new interpretation procedures that accentuate the educational implications to be drawn from test scores. This paper describes several features, based upon the Rasch difficulty and ability…
Measuring Student Learning with Item Response Theory
ERIC Educational Resources Information Center
Lee, Young-Jin; Palazzo, David J.; Warnakulasooriya, Rasil; Pritchard, David E.
2008-01-01
We investigate short-term learning from hints and feedback in a Web-based physics tutoring system. Both the skill of students and the difficulty and discrimination of items were determined by applying item response theory (IRT) to the first answers of students who are working on for-credit homework items in an introductory Newtonian physics…
ERIC Educational Resources Information Center
Choi, Seung W.; Podrabsky, Tracy; McKinney, Natalie
2012-01-01
Computerized adaptive testing (CAT) enables efficient and flexible measurement of latent constructs. The majority of educational and cognitive measurement constructs are based on dichotomous item response theory (IRT) models. An integral part of developing various components of a CAT system is conducting simulations using both known and empirical…
Using Item Response Theory and Adaptive Testing in Online Career Assessment
ERIC Educational Resources Information Center
Betz, Nancy E.; Turner, Brandon M.
2011-01-01
The present article describes the potential utility of item response theory (IRT) and adaptive testing for scale evaluation and for web-based career assessment. The article describes the principles of both IRT and adaptive testing and then illustrates these with reference to data analyses and simulation studies of the Career Confidence Inventory…
An Evaluation of Item Response Theory Classification Accuracy and Consistency Indices
ERIC Educational Resources Information Center
Wyse, Adam E.; Hao, Shiqi
2012-01-01
This article introduces two new classification consistency indices that can be used when item response theory (IRT) models have been applied. The new indices are shown to be related to Rudner's classification accuracy index and Guo's classification accuracy index. The Rudner- and Guo-based classification accuracy and consistency indices are…
An Item Response Theory Model for Test Bias.
ERIC Educational Resources Information Center
Shealy, Robin; Stout, William
This paper presents a conceptualization of test bias for standardized ability tests which is based on multidimensional, non-parametric, item response theory. An explanation of how individually-biased items can combine through a test score to produce test bias is provided. It is contended that bias, although expressed at the item level, should be…
ERIC Educational Resources Information Center
Tzou, Jean Yuh-Jin; Kim, Eunha; Waldheim, Kim
2012-01-01
Positive Feminist Therapy (PFT) is a strength-based culturally responsive therapy model specifically designed for helping Chinese women facing marital conflicts and divorce, integrating Empowerment Feminist Therapy, systems theory, and positive psychology. To help clients become change agents, PFT uses clients' existing strengths to develop…
Test Theories, Educational Priorities and Reliability of Public Examinations in England
ERIC Educational Resources Information Center
Baird, Jo-Anne; Black, Paul
2013-01-01
Much has already been written on the controversies surrounding the use of different test theories in educational assessment. Other authors have noted the prevalence of classical test theory over item response theory in practice. This Special Issue draws together articles based upon work conducted on the Reliability Programme for England's…
The Nature of Prejudice Revisited: Implications for Counseling Intervention.
ERIC Educational Resources Information Center
Ponterotto, Joseph G.
1991-01-01
Presents perspective on prejudice and counseling's role in prejudice prevention. Documents increasing race-based intergroup conflict; explaining conflict vis-a-vis racial identity theory, rapidly changing demographics, and Flight or Fight Response Theory of Racial Stress. Presents developmentally based interventions across elementary, high school,…
Monomer volume fraction profiles in pH responsive planar polyelectrolyte brushes
Mahalik, Jyoti P.; Yang, Yubo; Deodhar, Chaitra V.; ...
2016-03-06
Spatial dependencies of monomer volume fraction profiles of pH responsive polyelectrolyte brushes were investigated using field theories and neutron reflectivity experiments. In particular, planar polyelectrolyte brushes in good solvent were studied and direct comparisons between predictions of the theories and experimental measurements are presented. The comparisons between the theories and the experimental data reveal that solvent entropy and ion-pairs resulting from adsorption of counterions from the added salt play key roles in affecting the monomer distribution and must be taken into account in modeling polyelectrolyte brushes. Furthermore, the utility of this physics-based approach based on these theories for the predictionmore » and interpretation of neutron reflectivity profiles in the context of pH responsive planar polyelectrolyte brushes such as polybasic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and polyacidic poly(methacrylic acid) (PMAA) brushes is demonstrated. The approach provides a quantitative way of estimating molecular weights of the polymers polymerized using surface-initiated atom transfer radical polymerization.« less
An endochronic theory for transversely isotropic fibrous composites
NASA Technical Reports Server (NTRS)
Pindera, M. J.; Herakovich, C. T.
1981-01-01
A rational methodology of modelling both nonlinear and elastic dissipative response of transversely isotropic fibrous composites is developed and illustrated with the aid of the observed response of graphite-polyimide off-axis coupons. The methodology is based on the internal variable formalism employed within the text of classical irreversible thermodynamics and entails extension of Valanis' endochronic theory to transversely isotropic media. Applicability of the theory to prediction of various response characteristics of fibrous composites is illustrated by accurately modelling such often observed phenomena as: stiffening reversible behavior along fiber direction; dissipative response in shear and transverse tension characterized by power-laws with different hardening exponents; permanent strain accumulation; nonlinear unloading and reloading; and stress-interaction effects.
ERIC Educational Resources Information Center
Bontempo, Robert
1993-01-01
Describes a method for assessing the quality of translations based on item response theory (IRT). Results from the IRT technique with French and Chinese versions of a scale measuring individualism-collectivism for samples of 250 U.S., 357 French, and 290 Chinese undergraduates show how several biased items are detected. (SLD)
An Explanatory Item Response Theory Approach for a Computer-Based Case Simulation Test
ERIC Educational Resources Information Center
Kahraman, Nilüfer
2014-01-01
Problem: Practitioners working with multiple-choice tests have long utilized Item Response Theory (IRT) models to evaluate the performance of test items for quality assurance. The use of similar applications for performance tests, however, is often encumbered due to the challenges encountered in working with complicated data sets in which local…
Density matrix perturbation theory for magneto-optical response of periodic insulators
NASA Astrophysics Data System (ADS)
Lebedeva, Irina; Tokatly, Ilya; Rubio, Angel
2015-03-01
Density matrix perturbation theory offers an ideal theoretical framework for the description of response of solids to arbitrary electromagnetic fields. In particular, it allows to consider perturbations introduced by uniform electric and magnetic fields under periodic boundary conditions, though the corresponding potentials break the translational invariance of the Hamiltonian. We have implemented the density matrix perturbation theory in the open-source Octopus code on the basis of the efficient Sternheimer approach. The procedures for responses of different order to electromagnetic fields, including electric polarizability, orbital magnetic susceptibility and magneto-optical response, have been developed and tested by comparison with the results for finite systems and for wavefunction-based perturbation theory, which is already available in the code. Additional analysis of the orbital magneto-optical response is performed on the basis of analytical models. Symmetry limitations to observation of the magneto-optical response are discussed. The financial support from the Marie Curie Fellowship PIIF-GA-2012-326435 (RespSpatDisp) is gratefully acknowledged.
Using Rasch Analysis to Inform Rating Scale Development
ERIC Educational Resources Information Center
Van Zile-Tamsen, Carol
2017-01-01
The use of surveys, questionnaires, and rating scales to measure important outcomes in higher education is pervasive, but reliability and validity information is often based on problematic Classical Test Theory approaches. Rasch Analysis, based on Item Response Theory, provides a better alternative for examining the psychometric quality of rating…
Hagerty, Thomas A; Samuels, William; Norcini-Pala, Andrea; Gigliotti, Eileen
2017-04-01
A confirmatory factor analysis of data from the responses of 12,436 patients to 16 items on the Consumer Assessment of Healthcare Providers and Systems-Hospital survey was used to test a latent factor structure based on Peplau's middle-range theory of interpersonal relations. A two-factor model based on Peplau's theory fit these data well, whereas a three-factor model also based on Peplau's theory fit them excellently and provided a suitable alternate factor structure for the data. Though neither the two- nor three-factor model fit as well as the original factor structure, these results support using Peplau's theory to demonstrate nursing's extensive contribution to the experiences of hospitalized patients.
Toward a Responsibility-Catering Prioritarian Ethical Theory of Risk.
Wikman-Svahn, Per; Lindblom, Lars
2018-03-05
Standard tools used in societal risk management such as probabilistic risk analysis or cost-benefit analysis typically define risks in terms of only probabilities and consequences and assume a utilitarian approach to ethics that aims to maximize expected utility. The philosopher Carl F. Cranor has argued against this view by devising a list of plausible aspects of the acceptability of risks that points towards a non-consequentialist ethical theory of societal risk management. This paper revisits Cranor's list to argue that the alternative ethical theory responsibility-catering prioritarianism can accommodate the aspects identified by Cranor and that the elements in the list can be used to inform the details of how to view risks within this theory. An approach towards operationalizing the theory is proposed based on a prioritarian social welfare function that operates on responsibility-adjusted utilities. A responsibility-catering prioritarian ethical approach towards managing risks is a promising alternative to standard tools such as cost-benefit analysis.
Lau-Walker, Margaret
2006-02-01
This paper analyses the two prominent psychological theories of patient response--illness representation and self-efficacy--and explore the possibilities of the development of a conceptual individualized care model that would make use of both theories. Analysis of the literature established common themes that were used as the basis to form a conceptual framework intended to assist in the joint application of these theories to therapeutic settings. Both theories emphasize personal experience, pre-construction of self, individual response to illness and treatment, and that the patients' beliefs are more influential in their recovery than the severity of the illness. Where the theories are most divergent is their application to therapeutic interventions, which reflects the different sources of influence that each theory emphasizes. Based on their similarities and differences it is possible to integrate the two theories into a conceptual care model. The Interactive Care Model combines both theories of patient response and provides an explicit framework for further research into the design of effective therapeutic interventions in rehabilitation care.
NASA Technical Reports Server (NTRS)
Pototzky, Anthony S.; Zeiler, Thomas A.; Perry, Boyd, III
1989-01-01
This paper describes and illustrates two ways of performing time-correlated gust-load calculations. The first is based on Matched Filter Theory; the second on Random Process Theory. Both approaches yield theoretically identical results and represent novel applications of the theories, are computationally fast, and may be applied to other dynamic-response problems. A theoretical development and example calculations using both Matched Filter Theory and Random Process Theory approaches are presented.
NASA Technical Reports Server (NTRS)
Pototzky, Anthony S.; Zeiler, Thomas A.; Perry, Boyd, III
1989-01-01
Two ways of performing time-correlated gust-load calculations are described and illustrated. The first is based on Matched Filter Theory; the second on Random Process Theory. Both approaches yield theoretically identical results and represent novel applications of the theories, are computationally fast, and may be applied to other dynamic-response problems. A theoretical development and example calculations using both Matched Filter Theory and Random Process Theory approaches are presented.
Newman, Ian R; Gibb, Maia; Thompson, Valerie A
2017-07-01
It is commonly assumed that belief-based reasoning is fast and automatic, whereas rule-based reasoning is slower and more effortful. Dual-Process theories of reasoning rely on this speed-asymmetry explanation to account for a number of reasoning phenomena, such as base-rate neglect and belief-bias. The goal of the current study was to test this hypothesis about the relative speed of belief-based and rule-based processes. Participants solved base-rate problems (Experiment 1) and conditional inferences (Experiment 2) under a challenging deadline; they then gave a second response in free time. We found that fast responses were informed by rules of probability and logical validity, and that slow responses incorporated belief-based information. Implications for Dual-Process theories and future research options for dissociating Type I and Type II processes are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
ERIC Educational Resources Information Center
Klinger, Don A.; Rogers, W. Todd
2003-01-01
The estimation accuracy of procedures based on classical test score theory and item response theory (generalized partial credit model) were compared for examinations consisting of multiple-choice and extended-response items. Analysis of British Columbia Scholarship Examination results found an error rate of about 10 percent for both methods, with…
ERIC Educational Resources Information Center
Van der Elst, Wim; Ouwehand, Carolijn; van Rijn, Peter; Lee, Nikki; Van Boxtel, Martin; Jolles, Jelle
2013-01-01
The purpose of the present study was to evaluate the psychometric properties of a shortened version of the Raven Standard Progressive Matrices (SPM) under an item response theory framework (the one- and two-parameter logistic models). The shortened Raven SPM was administered to N = 453 cognitively healthy adults aged between 24 and 83 years. The…
ERIC Educational Resources Information Center
Lopez, Leslie Ann
2013-01-01
Video has been shown to be an effective tool for synthesizing theory and connecting theory to practice in meaningful ways. This design-based research study examined how localized video of a practicing teacher impacted pre-service teachers' ability to learn culturally responsive teaching (CRT) methods and targeted strategies in an online…
ERIC Educational Resources Information Center
Yeh, C. Rosa; Tao, Yu-Hui
2012-01-01
The use of personal response systems (PRS) in classrooms is gaining popularity in the higher education institutes of Taiwan. However, past research rarely adopts theories from the information system domains, and their focus was primarily on the UK and US context. Therefore, this study adopted a theory-based approach to explore the perceptions of…
Reconsidering Genre Theory in K-12 Schools: A Response to School Reforms in the United States
ERIC Educational Resources Information Center
Gebhard, Meg; Harman, Ruth
2011-01-01
Education reforms in the United States have placed new demands on English language learners (ELLs) and their teachers in K-12 public schools. In response, many teachers, teacher educators, and literacy scholars are reexamining genre theory and genre-based pedagogy as a way of supporting the academic literacy development of the growing number of…
Improving measurement of injection drug risk behavior using item response theory.
Janulis, Patrick
2014-03-01
Recent research highlights the multiple steps to preparing and injecting drugs and the resultant viral threats faced by drug users. This research suggests that more sensitive measurement of injection drug HIV risk behavior is required. In addition, growing evidence suggests there are gender differences in injection risk behavior. However, the potential for differential item functioning between genders has not been explored. To explore item response theory as an improved measurement modeling technique that provides empirically justified scaling of injection risk behavior and to examine for potential gender-based differential item functioning. Data is used from three studies in the National Institute on Drug Abuse's Criminal Justice Drug Abuse Treatment Studies. A two-parameter item response theory model was used to scale injection risk behavior and logistic regression was used to examine for differential item functioning. Item fit statistics suggest that item response theory can be used to scale injection risk behavior and these models can provide more sensitive estimates of risk behavior. Additionally, gender-based differential item functioning is present in the current data. Improved measurement of injection risk behavior using item response theory should be encouraged as these models provide increased congruence between construct measurement and the complexity of injection-related HIV risk. Suggestions are made to further improve injection risk behavior measurement. Furthermore, results suggest direct comparisons of composite scores between males and females may be misleading and future work should account for differential item functioning before comparing levels of injection risk behavior.
ERIC Educational Resources Information Center
Bergner, Yoav; Droschler, Stefan; Kortemeyer, Gerd; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.
2012-01-01
We apply collaborative filtering (CF) to dichotomously scored student response data (right, wrong, or no interaction), finding optimal parameters for each student and item based on cross-validated prediction accuracy. The approach is naturally suited to comparing different models, both unidimensional and multidimensional in ability, including a…
ERIC Educational Resources Information Center
Dallavis, Christian
2013-01-01
This article explores the intersection of culturally responsive pedagogy and faith-based schooling. The author presents a portion of a larger ethnographic research project conducted at a Catholic elementary school that serves a predominantly Latino population in urban Chicago. This work contributes to theories of culturally responsive education by…
Rezazadeh, Afsaneh; Solhi, Mahnaz; Azam, Kamal
2015-01-01
Adolescence is a sensitive period of acquiring normal and abnormal habits for all oflife. The study investigates determinants of responsibility for health, spiritual health and interpersonal relations and predictive factors based on the theory of planned behavior in high school girl students in Tabriz. In this Cross-sectional study, 340 students were selected thorough multi-stage sampling. An author-made questionnaire based on standard questionnaires of Health Promotion and Lifestyle II (HPLPII), spiritual health standards (Palutzian & Ellison) and components of the theory of planned behavior (attitudes, subjective norms, perceived behavioral control, and behavioral intention) was used for data collection. The questionnaire was validated in a pilot study. Data were analyzed using SPSS v.15 and descriptive and analytical tests (Chi-square test, Pearson correlation co-efficient and liner regression test in backward method). Students' responsibility for health, spiritual health, interpersonal relationships, and concepts of theory of planned behavior was moderate. We found a significant positive correlation (p<0/001) among all concepts of theory of planned behavior. Attitude and perceived behavioral control predicted 35% of intention of behavioral change (p<0.001). Attitude, subjective norms, and perceived behavioral control predicted 74% of behavioral change in accountability for health (p<0.0001), 56% for behavioral change in spiritual health (p<0.0001) and 63% for behavioral change in interpersonal relationship (p<0.0001). Status of responsibility for health, spiritual health and interpersonal relationships of students was moderate. Hence, behavioral intention and its determinants such as perceived behavioral control should be noted in promoting intervention programs.
NASA Technical Reports Server (NTRS)
Tessler, Alexander; Gherlone, Marco; Versino, Daniele; DiSciuva, Marco
2012-01-01
This paper reviews the theoretical foundation and computational mechanics aspects of the recently developed shear-deformation theory, called the Refined Zigzag Theory (RZT). The theory is based on a multi-scale formalism in which an equivalent single-layer plate theory is refined with a robust set of zigzag local layer displacements that are free of the usual deficiencies found in common plate theories with zigzag kinematics. In the RZT, first-order shear-deformation plate theory is used as the equivalent single-layer plate theory, which represents the overall response characteristics. Local piecewise-linear zigzag displacements are used to provide corrections to these overall response characteristics that are associated with the plate heterogeneity and the relative stiffnesses of the layers. The theory does not rely on shear correction factors and is equally accurate for homogeneous, laminated composite, and sandwich beams and plates. Regardless of the number of material layers, the theory maintains only seven kinematic unknowns that describe the membrane, bending, and transverse shear plate-deformation modes. Derived from the virtual work principle, RZT is well-suited for developing computationally efficient, C(sup 0)-continuous finite elements; formulations of several RZT-based elements are highlighted. The theory and its finite element approximations thus provide a unified and reliable computational platform for the analysis and design of high-performance load-bearing aerospace structures.
NASA Technical Reports Server (NTRS)
Tessler, Alexander; Gherlone, Marco; Versino, Daniele; Di Sciuva, Marco
2012-01-01
This paper reviews the theoretical foundation and computational mechanics aspects of the recently developed shear-deformation theory, called the Refined Zigzag Theory (RZT). The theory is based on a multi-scale formalism in which an equivalent single-layer plate theory is refined with a robust set of zigzag local layer displacements that are free of the usual deficiencies found in common plate theories with zigzag kinematics. In the RZT, first-order shear-deformation plate theory is used as the equivalent single-layer plate theory, which represents the overall response characteristics. Local piecewise-linear zigzag displacements are used to provide corrections to these overall response characteristics that are associated with the plate heterogeneity and the relative stiffnesses of the layers. The theory does not rely on shear correction factors and is equally accurate for homogeneous, laminated composite, and sandwich beams and plates. Regardless of the number of material layers, the theory maintains only seven kinematic unknowns that describe the membrane, bending, and transverse shear plate-deformation modes. Derived from the virtual work principle, RZT is well-suited for developing computationally efficient, C0-continuous finite elements; formulations of several RZT-based elements are highlighted. The theory and its finite elements provide a unified and reliable computational platform for the analysis and design of high-performance load-bearing aerospace structures.
Rethinking the Introduction of Particle Theory: A Substance-Based Framework
ERIC Educational Resources Information Center
Johnson, Philip; Papageorgiou, George
2010-01-01
In response to extensive research exposing students' poor understanding of the particle theory of matter, this article argues that the conceptual framework within which the theory is introduced could be a limiting factor. The standard school particle model is characterized as operating within a "solids, liquids, and gases" framework.…
Nash Equilibria in Theory of Reasoned Action
NASA Astrophysics Data System (ADS)
Almeida, Leando; Cruz, José; Ferreira, Helena; Pinto, Alberto Adrego
2009-08-01
Game theory and Decision Theory have been applied to many different areas such as Physics, Economics, Biology, etc. In its application to Psychology, we introduce, in the literature, a Game Theoretical Model of Planned Behavior or Reasoned Action by establishing an analogy between two specific theories. In this study we take in account that individual decision-making is an outcome of a process where group decisions can determine individual probabilistic behavior. Using Game Theory concepts, we describe how intentions can be transformed in behavior and according to the Nash Equilibrium, this process will correspond to the best individual decision/response taking in account the collective response. This analysis can be extended to several examples based in the Game Theoretical Model of Planned Behavior or Reasoned Action.
NASA Technical Reports Server (NTRS)
Lee, Timothy J.; Srinivasan, Parthiban; Head-Gordon, Martin; Huo, Winifred (Technical Monitor)
1998-01-01
Electronic excitation energies are determined using single-reference based theories derived from response equations involving perturbation theory and coupled-cluster theory. These methods are applied to the singlet manifold of excited electronic states of the HClO, HBrO, HOClO, HOBrO, HClO2, and HBrO2 molecules. The reliability of the various perturbation theory approaches is assessed by comparison to the linear-response singles and doubles coupled-cluster (LRCCSD) method. The excitation energies for the Y-XO compounds are compared and contrasted for Y=H and HO, and X=Cl and Br. A similar comparison is performed for the H-XO2 compounds.
Interlaminar shear stress effects on the postbuckling response of graphite-epoxy panels
NASA Technical Reports Server (NTRS)
Engelstad, S. P.; Knight, N. F., Jr.; Reddy, J. N.
1990-01-01
The influence of shear flexibility on overall postbuckling response was assessed, and transverse shear stress distributions in relation to panel failure were examined. Nonlinear postbuckling results are obtained for finite element models based on classical laminated plate theory and first-order shear deformation theory. Good correlation between test and analysis is obtained. The results presented analytically substantiate the experimentally observed failure mode.
ERIC Educational Resources Information Center
Wilson, Mark; Allen, Diane D.; Li, Jun Corser
2006-01-01
This paper compares the approach and resultant outcomes of item response models (IRMs) and classical test theory (CTT). First, it reviews basic ideas of CTT, and compares them to the ideas about using IRMs introduced in an earlier paper. It then applies a comparison scheme based on the AERA/APA/NCME "Standards for Educational and…
Comparing the Fit of Item Response Theory and Factor Analysis Models
ERIC Educational Resources Information Center
Maydeu-Olivares, Alberto; Cai, Li; Hernandez, Adolfo
2011-01-01
Linear factor analysis (FA) models can be reliably tested using test statistics based on residual covariances. We show that the same statistics can be used to reliably test the fit of item response theory (IRT) models for ordinal data (under some conditions). Hence, the fit of an FA model and of an IRT model to the same data set can now be…
Many-body theory of electrical, thermal and optical response of molecular heterojunctions
NASA Astrophysics Data System (ADS)
Bergfield, Justin Phillip
In this work, we develop a many-body theory of electronic transport through single molecule junctions based on nonequilibrium Green's functions (NEGFs). The central quantity of this theory is the Coulomb self-energy matrix of the junction SigmaC. SigmaC is evaluated exactly in the sequential-tunneling limit, and the correction due to finite lead-molecule tunneling is evaluated using a conserving approximation based on diagrammatic perturbation theory on the Keldysh contour. In this way, tunneling processes are included to infinite order, meaning that any approximation utilized is a truncation in the physical processes considered rather than in the order of those processes. Our theory reproduces the key features of both the Coulomb blockade and coherent transport regimes simultaneously in a single unified theory. Nonperturbative effects of intramolecular correlations are included, which are necessary to accurately describe the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap, essential for a quantitative theory of transport. This work covers four major topics related to transport in single-molecule junctions. First, we use our many-body theory to calculate the nonlinear electrical response of the archetypal Au-1,4-benzenedithiol-Au junction and find irregularly shaped 'molecular diamonds' which have been experimentally observed in some larger molecules but which are inaccessible to existing theoretical approaches. Next, we extend our theory to include heat transport and develop an exact expression for the heat current in an interacting nanostructure. Using this result, we discover that quantum coherence can strongly enhance the thermoelectric response of a device, a result with a number of technological applications. We then develop the formalism to include multi-orbital lead-molecule contacts and multi-channel leads, both of which strongly affect the observable transport. Lastly, we include a dynamic screening correction to Sigma C and investigate the optoelectric response of several molecular junctions.
Coriani, Sonia; Høst, Stinne; Jansík, Branislav; Thøgersen, Lea; Olsen, Jeppe; Jørgensen, Poul; Reine, Simen; Pawłowski, Filip; Helgaker, Trygve; Sałek, Paweł
2007-04-21
A linear-scaling implementation of Hartree-Fock and Kohn-Sham self-consistent field theories for the calculation of frequency-dependent molecular response properties and excitation energies is presented, based on a nonredundant exponential parametrization of the one-electron density matrix in the atomic-orbital basis, avoiding the use of canonical orbitals. The response equations are solved iteratively, by an atomic-orbital subspace method equivalent to that of molecular-orbital theory. Important features of the subspace method are the use of paired trial vectors (to preserve the algebraic structure of the response equations), a nondiagonal preconditioner (for rapid convergence), and the generation of good initial guesses (for robust solution). As a result, the performance of the iterative method is the same as in canonical molecular-orbital theory, with five to ten iterations needed for convergence. As in traditional direct Hartree-Fock and Kohn-Sham theories, the calculations are dominated by the construction of the effective Fock/Kohn-Sham matrix, once in each iteration. Linear complexity is achieved by using sparse-matrix algebra, as illustrated in calculations of excitation energies and frequency-dependent polarizabilities of polyalanine peptides containing up to 1400 atoms.
Dehdari, T; Hassani, L; Shojaeizadeh, D; Hajizadeh, E; Nedjat, S; Abedini, M
2016-01-01
Given the importance of papanicolaou (Pap) test in the early detection and timely treatment of cervical cancer, present study was designed to determine predictors of a sample of Iranian women's intention to first Pap test practice based on the protection motivation theory (PMT) variables. In this cross-sectional study, a total of 240 women referral to the 30 primary health care clinics were selected. They completed a developed scale based on PMT variables including intention, perceived vulnerability and severity, fear, response costs, response efficacy and self-efficacy. Path analysis was used to determine the association between predictive factors and intention. The results showed that PMT had goodness of fit with a χ2/df = 2.37, df = 28, P= 0.001 and RMSEA = 0.076. PMT explained 42% of the variance in women's intention to get first Pap smear test. Self-efficacy (b = 0.55, P< 0.001) and response efficacy (b = 0.19, P< 0.001) were found to be the predictors of intention. These findings may be used to develop tailored, theory-based educational interventions associated with Pap testing among women.
Nozari, Nazbanou; Dell, Gary S.; Schwartz, Myrna F.
2011-01-01
Despite the existence of speech errors, verbal communication is successful because speakers can detect (and correct) their errors. The standard theory of speech-error detection, the perceptual-loop account, posits that the comprehension system monitors production output for errors. Such a comprehension-based monitor, however, cannot explain the double dissociation between comprehension and error-detection ability observed in the aphasic patients. We propose a new theory of speech-error detection which is instead based on the production process itself. The theory borrows from studies of forced-choice-response tasks the notion that error detection is accomplished by monitoring response conflict via a frontal brain structure, such as the anterior cingulate cortex. We adapt this idea to the two-step model of word production, and test the model-derived predictions on a sample of aphasic patients. Our results show a strong correlation between patients’ error-detection ability and the model’s characterization of their production skills, and no significant correlation between error detection and comprehension measures, thus supporting a production-based monitor, generally, and the implemented conflict-based monitor in particular. The successful application of the conflict-based theory to error-detection in linguistic, as well as non-linguistic domains points to a domain-general monitoring system. PMID:21652015
Trierweiller, Andréa Cristina; Peixe, Blênio César Severo; Tezza, Rafael; Bornia, Antonio Cezar; de Andrade, Dalton Francisco; Campos, Lucila Maria de Souza
2012-01-01
Growing challenges with respect to preserving the environment have forced changes in company operational structures. Thus, the objective of this article is to measure the evidence of Environmental Management using the Item Response Theory, based on website analysis from Brazilian industrial companies from sectors defined through the scope of the research. This is a qualitative, exploratory, and descriptive study related to an information collection and analysis instrument. The general view of the research problem with respect to the phenomenon under study in based on multi-case studies, with the methodological outline based on the theoretical reference used. Primary data was gathered from 270 company websites from 7 different Brazilian sectors and led to the creation of 26 items approved by environmental specialists. The results were attained with the measuring of Environmental Management evidence via the Item Response Theory, providing a clear order of the items involved based on each item's level of difficulty, quality, and propriety. This permitted the measurement of each item's quality and propriety, as well as that of the respondents, placing them on the same analysis scale. Increasing the number of items and companies involved is suggested fEor future research in order to permit broader sector analysis.
Brosschot, Jos F; Verkuil, Bart; Thayer, Julian F
2017-03-01
Based on neurobiological and evolutionary arguments, the generalized unsafety theory of stress (GUTS) hypothesizes that the stress response is a default response, and that chronic stress responses are caused by generalized unsafety (GU), independent of stressors or their cognitive representation. Three highly prevalent conditions are particularly vulnerable to becoming 'compromised' in terms of GU, and carry considerable health risks: Thus, GUTS critically revises and expands stress theory, by focusing on safety instead of threat, and by including risk factors that have hitherto not been attributed to stress. Copyright © 2016 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Cao, Yi; Lu, Ru; Tao, Wei
2014-01-01
The local item independence assumption underlying traditional item response theory (IRT) models is often not met for tests composed of testlets. There are 3 major approaches to addressing this issue: (a) ignore the violation and use a dichotomous IRT model (e.g., the 2-parameter logistic [2PL] model), (b) combine the interdependent items to form a…
ERIC Educational Resources Information Center
Deng, Weiling; Monfils, Lora
2017-01-01
Using simulated data, this study examined the impact of different levels of stringency of the valid case inclusion criterion on item response theory (IRT)-based true score equating over 5 years in the context of K-12 assessment when growth in student achievement is expected. Findings indicate that the use of the most stringent inclusion criterion…
Brosschot, Jos F.; Thayer, Julian F.
2018-01-01
Prolonged physiological stress responses form an important risk factor for disease. According to neurobiological and evolution-theoretical insights the stress response is a default response that is always “on” but inhibited by the prefrontal cortex when safety is perceived. Based on these insights the Generalized Unsafety Theory of Stress (GUTS) states that prolonged stress responses are due to generalized and largely unconsciously perceived unsafety rather than stressors. This novel perspective necessitates a reconstruction of current stress theory, which we address in this paper. We discuss a variety of very common situations without stressors but with prolonged stress responses, that are not, or not likely to be caused by stressors, including loneliness, low social status, adult life after prenatal or early life adversity, lack of a natural environment, and less fit bodily states such as obesity or fatigue. We argue that in these situations the default stress response may be chronically disinhibited due to unconsciously perceived generalized unsafety. Also, in chronic stress situations such as work stress, the prolonged stress response may be mainly caused by perceived unsafety in stressor-free contexts. Thus, GUTS identifies and explains far more stress-related physiological activity that is responsible for disease and mortality than current stress theories. PMID:29518937
Brosschot, Jos F; Verkuil, Bart; Thayer, Julian F
2018-03-07
Prolonged physiological stress responses form an important risk factor for disease. According to neurobiological and evolution-theoretical insights the stress response is a default response that is always "on" but inhibited by the prefrontal cortex when safety is perceived. Based on these insights the Generalized Unsafety Theory of Stress (GUTS) states that prolonged stress responses are due to generalized and largely unconsciously perceived unsafety rather than stressors. This novel perspective necessitates a reconstruction of current stress theory, which we address in this paper. We discuss a variety of very common situations without stressors but with prolonged stress responses, that are not, or not likely to be caused by stressors, including loneliness, low social status, adult life after prenatal or early life adversity, lack of a natural environment, and less fit bodily states such as obesity or fatigue. We argue that in these situations the default stress response may be chronically disinhibited due to unconsciously perceived generalized unsafety. Also, in chronic stress situations such as work stress, the prolonged stress response may be mainly caused by perceived unsafety in stressor-free contexts. Thus, GUTS identifies and explains far more stress-related physiological activity that is responsible for disease and mortality than current stress theories.
Higher-Order Theory for Functionally Graded Materials
NASA Technical Reports Server (NTRS)
Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.
1999-01-01
This paper presents the full generalization of the Cartesian coordinate-based higher-order theory for functionally graded materials developed by the authors during the past several years. This theory circumvents the problematic use of the standard micromechanical approach, based on the concept of a representative volume element, commonly employed in the analysis of functionally graded composites by explicitly coupling the local (microstructural) and global (macrostructural) responses. The theoretical framework is based on volumetric averaging of the various field quantities, together with imposition of boundary and interfacial conditions in an average sense between the subvolumes used to characterize the composite's functionally graded microstructure. The generalization outlined herein involves extension of the theoretical framework to enable the analysis of materials characterized by spatially variable microstructures in three directions. Specialization of the generalized theoretical framework to previously published versions of the higher-order theory for materials functionally graded in one and two directions is demonstrated. In the applications part of the paper we summarize the major findings obtained with the one-directional and two-directional versions of the higher-order theory. The results illustrate both the fundamental issues related to the influence of microstructure on microscopic and macroscopic quantities governing the response of composites and the technologically important applications. A major issue addressed herein is the applicability of the classical homogenization schemes in the analysis of functionally graded materials. The technologically important applications illustrate the utility of functionally graded microstructures in tailoring the response of structural components in a variety of applications involving uniform and gradient thermomechanical loading.
Peri, Tuvia; Gofman, Mordechai; Tal, Shahar; Tuval-Mashiach, Rivka
2015-01-01
Exposure to the trauma memory is the common denominator of most evidence-based interventions for posttraumatic stress disorder (PTSD). Although exposure-based therapies aim to change associative learning networks and negative cognitions related to the trauma memory, emotional interactions between patient and therapist have not been thoroughly considered in past evaluations of exposure-based therapy. This work focuses on recent discoveries of the mirror-neuron system and the theory of embodied simulation (ES). These conceptualizations may add a new perspective to our understanding of change processes in exposure-based treatments for PTSD patients. It is proposed that during exposure to trauma memories, emotional responses of the patient are transferred to the therapist through ES and then mirrored back to the patient in a modulated way. This process helps to alleviate the patient's sense of loneliness and enhances his or her ability to exert control over painful, trauma-related emotional responses. ES processes may enhance the integration of clinical insights originating in psychoanalytic theories—such as holding, containment, projective identification, and emotional attunement—with cognitive behavioral theories of learning processes in the alleviation of painful emotional responses aroused by trauma memories. These processes are demonstrated through a clinical vignette from an exposure-based therapy with a trauma survivor. Possible clinical implications for the importance of face-to-face relationships during exposure-based therapy are discussed. PMID:26593097
Operant Variability and Voluntary Action
ERIC Educational Resources Information Center
Neuringer, Allen; Jensen, Greg
2010-01-01
A behavior-based theory identified 2 characteristics of voluntary acts. The first, extensively explored in operant-conditioning experiments, is that voluntary responses produce the reinforcers that control them. This bidirectional relationship--in which reinforcer depends on response and response on reinforcer--demonstrates the functional nature…
Interlaminar shear stress effects on the postbuckling response of graphite-epoxy panels
NASA Technical Reports Server (NTRS)
Engelstad, S. P.; Reddy, J. N.; Knight, N. F., Jr.
1990-01-01
The objectives of the study are to assess the influence of shear flexibility on overall postbuckling response, and to examine transverse shear stress distributions in relation to panel failure. Nonlinear postbuckling results are obtained for finite element models based on classical laminated plate theory and first-order shear deformation theory. Good correlation between test and analysis is obtained. The results presented in this paper analytically substantiate the experimentally observed failure mode.
Petrillo, Jennifer; Cano, Stefan J; McLeod, Lori D; Coon, Cheryl D
2015-01-01
To provide comparisons and a worked example of item- and scale-level evaluations based on three psychometric methods used in patient-reported outcome development-classical test theory (CTT), item response theory (IRT), and Rasch measurement theory (RMT)-in an analysis of the National Eye Institute Visual Functioning Questionnaire (VFQ-25). Baseline VFQ-25 data from 240 participants with diabetic macular edema from a randomized, double-masked, multicenter clinical trial were used to evaluate the VFQ at the total score level. CTT, RMT, and IRT evaluations were conducted, and results were assessed in a head-to-head comparison. Results were similar across the three methods, with IRT and RMT providing more detailed diagnostic information on how to improve the scale. CTT led to the identification of two problematic items that threaten the validity of the overall scale score, sets of redundant items, and skewed response categories. IRT and RMT additionally identified poor fit for one item, many locally dependent items, poor targeting, and disordering of over half the response categories. Selection of a psychometric approach depends on many factors. Researchers should justify their evaluation method and consider the intended audience. If the instrument is being developed for descriptive purposes and on a restricted budget, a cursory examination of the CTT-based psychometric properties may be all that is possible. In a high-stakes situation, such as the development of a patient-reported outcome instrument for consideration in pharmaceutical labeling, however, a thorough psychometric evaluation including IRT or RMT should be considered, with final item-level decisions made on the basis of both quantitative and qualitative results. Copyright © 2015. Published by Elsevier Inc.
NASA Astrophysics Data System (ADS)
Pérez-Moreno, Javier; Clays, Koen; Kuzyk, Mark G.
2010-08-01
We introduce a self-consistent theory for the description of the optical linear and nonlinear response of molecules that is based strictly on the results of the experimental characterization. We show how the Thomas-Kuhn sum-rules can be used to eliminate the dependence of the nonlinear response on parameters that are not directly measurable. Our approach leads to the successful modeling of the dispersion of the nonlinear response of complex molecular structures with different geometries (dipolar and octupolar), and can be used as a guide towards the modeling in terms of fundamental physical parameters.
Confirmation of the Conditional Outdoor Leadership Theory.
ERIC Educational Resources Information Center
Dixon, Tim; Priest, Simon
1991-01-01
Responses of 75 expert outdoor leaders from Canada and the United States concerning leadership in 12 hypothetical backpacking scenarios provided partial support for a theory that predicted probability of leadership style (democratic, autocratic, or abdicratic) based on favorability of conditions, task orientation, and relationship orientation.…
ERIC Educational Resources Information Center
Lee, Guemin; Park, In-Yong
2012-01-01
Previous assessments of the reliability of test scores for testlet-composed tests have indicated that item-based estimation methods overestimate reliability. This study was designed to address issues related to the extent to which item-based estimation methods overestimate the reliability of test scores composed of testlets and to compare several…
Evidence for an expectancy-based theory of avoidance behaviour.
Declercq, Mieke; De Houwer, Jan; Baeyens, Frank
2008-01-01
In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli.
Wirtz, Philip W; Rohrbeck, Cynthia A
2017-10-01
In order to formulate effective communication and intervention strategies to respond to the widespread lack of preparedness for public health crises resulting from natural and human-made disasters, researchers have developed models describing the interrelationships between factors associated with emergency preparedness decisions. Empirical research has generally assumed that two key elements of most health behavior theories-self-efficacy and response efficacy-additively influence the decision to prepare, despite compelling theoretical rationale for an interactive relationship. The few studies that have investigated interactions in preparedness outcomes have not tested the Social Cognitive Theory prediction that non-zero levels of both efficacy types are required before individuals will engage in any preparedness behavior. Based on the responses of 3,101 participants in the National Survey of Disaster Experiences and Preparedness, this study tested additive, interactive, and conditional main effect hypotheses about the influence of self-efficacy and response efficacy for dealing with terrorism on preparedness due to terrorism six years after the September 11, 2001, terrorist attacks. A significant self-efficacy × response efficacy interaction effect on preparedness was found, in addition to a significant response efficacy effect when perceived self-efficacy was zero, contrary to the expectation from Social Cognitive Theory. These results offer insights into the cognitive processes underlying individuals' decisions to prepare for disasters such as terrorist attacks, and highlight the importance of considering more complex theory-based cognitive interaction models in designing effective communication strategies to facilitate individual emergency preparedness.
Ratliff, Mary; Masen, Nicole; Sullivan, Stephen; Fleming, Michael F.; Carney, Paula
2013-01-01
This article demonstrates how to apply evidenced-based instructional design principles to develop a supplemental, online Responsible Conduct of Research (RCR) course. The supplement RCR course may serve to appropriately augment the National Institutes of Health (NIH) required RCR training. The way to ensure that an online RCR course is effective is to incorporate evidence-based learning theories into the development of the course content. This article specifically demonstrates application of Bloom’s taxonomy and Gagne’s Nine Instructional Events to a research misconduct course. At the conclusion, the reader will be able to apply evidence-based learning theories to the development of any online course. PMID:22861181
Boeschen Hospers, J Mirjam; Smits, Niels; Smits, Cas; Stam, Mariska; Terwee, Caroline B; Kramer, Sophia E
2016-04-01
We reevaluated the psychometric properties of the Amsterdam Inventory for Auditory Disability and Handicap (AIADH; Kramer, Kapteyn, Festen, & Tobi, 1995) using item response theory. Item response theory describes item functioning along an ability continuum. Cross-sectional data from 2,352 adults with and without hearing impairment, ages 18-70 years, were analyzed. They completed the AIADH in the web-based prospective cohort study "Netherlands Longitudinal Study on Hearing." A graded response model was fitted to the AIADH data. Category response curves, item information curves, and the standard error as a function of self-reported hearing ability were plotted. The graded response model showed a good fit. Item information curves were most reliable for adults who reported having hearing disability and less reliable for adults with normal hearing. The standard error plot showed that self-reported hearing ability is most reliably measured for adults reporting mild up to moderate hearing disability. This is one of the few item response theory studies on audiological self-reports. All AIADH items could be hierarchically placed on the self-reported hearing ability continuum, meaning they measure the same construct. This provides a promising basis for developing a clinically useful computerized adaptive test, where item selection adapts to the hearing ability of individuals, resulting in efficient assessment of hearing disability.
The Sequential Probability Ratio Test and Binary Item Response Models
ERIC Educational Resources Information Center
Nydick, Steven W.
2014-01-01
The sequential probability ratio test (SPRT) is a common method for terminating item response theory (IRT)-based adaptive classification tests. To decide whether a classification test should stop, the SPRT compares a simple log-likelihood ratio, based on the classification bound separating two categories, to prespecified critical values. As has…
NASA Technical Reports Server (NTRS)
Klein, R.
1972-01-01
A set of specially prepared digital tapes is reported which contain synchronized measurements of pilot scanning behavior, control response, and vehicle response obtained during instrument landing system approaches made in a fixed-base DC-8 transport simulator. The objective of the master tape is to provide a common data base which can be used by the research community to test theories, models, and methods for describing and analyzing control/display relations and interactions. The experimental conditions and tasks used to obtain the data and the detailed format of the tapes are described. Conventional instrument panel and controls were used, with simulated vertical gust and glide slope beam bend forcing functions. Continuous pilot eye fixations and scan traffic on the panel were measured. Both flight director and standard localizer/glide slope types of approaches were made, with both fixed and variable instrument range sensitivities.
Korean immigrant women's physical activity experience: a situation-specific theory.
Im, Eun-Ok; Chang, Sun Ju; Nguyen, Giang; Stringer, Lynn; Chee, Wonshik; Chee, Eunice
2015-01-01
To develop successful physical activity promotion programs for midlife immigrant women, especially for Korean immigrant midlife women, concrete theoretical bases are needed. However, virtually no theoretical frameworks and/or theories exist that can explain the influences of immigration transition on the physical activity experience of midlife immigrant women in general or Korean immigrant midlife women in specific. The purpose of this article is to present a situation-specific theory on physical activity experience of Korean immigrant midlife women (SPAKIM) with its development process. An integrative approach was used to develop the theory based on the midlife women's attitudes toward physical activity (MAPA) theory, the transitions theory, a review of the relevant literature, and two studies on midlife women's attitudes toward physical activity. The proposed theory includes nature of transitions, nonmodifiable and modifiable transition conditions, contexts of daily life, patterns of response, and nursing therapeutics as major concepts, and each major concept includes several related subconcepts. Because several concepts of the theory were developed mainly based on the literature review, the major concepts and related subconcepts need to be further developed and evaluated in future studies.
A description of the mechanical behavior of composite solid propellants based on molecular theory
NASA Technical Reports Server (NTRS)
Landel, R. F.
1976-01-01
Both the investigation and the representation of the stress-strain response (including rupture) of gum and filled elastomers can be based on a simple functional statement. Internally consistent experiments are used to sort out the effects of time, temperature, strain and crosslink density on gum rubbers. All effects are readily correlated and shown to be essentially independent of the elastomer when considered in terms of non-dimensionalized stress, strain and time. A semiquantitative molecular theory is developed to explain this result. The introduction of fillers modifies the response, but, guided by the framework thus provided, their effects can be readily accounted for.
Levels of Conceptual Development in Melodic Permutation Concepts Based on Piaget's Theory
ERIC Educational Resources Information Center
Larn, Ronald L.
1973-01-01
Article considered different ways in which subjects at different age levels solved a musical task involving melodic permutation. The differences in responses to the musical task between age groups were judged to be compatible with Piaget's theory of cognitive development. (Author/RK)
ERIC Educational Resources Information Center
Gardner, Howard; Connell, Michael
2000-01-01
Replies to "The Theory of Multiple Intelligences: A Case of Missing Cognitive Matter," also in this issue. Disagrees about the role theory of knowledge plays in the context of justification of multiple intelligences. Specifically, asserts that the article's criticisms based on philosophy of science claims and work with artificial neural…
Differential item functioning magnitude and impact measures from item response theory models.
Kleinman, Marjorie; Teresi, Jeanne A
2016-01-01
Measures of magnitude and impact of differential item functioning (DIF) at the item and scale level, respectively are presented and reviewed in this paper. Most measures are based on item response theory models. Magnitude refers to item level effect sizes, whereas impact refers to differences between groups at the scale score level. Reviewed are magnitude measures based on group differences in the expected item scores and impact measures based on differences in the expected scale scores. The similarities among these indices are demonstrated. Various software packages are described that provide magnitude and impact measures, and new software presented that computes all of the available statistics conveniently in one program with explanations of their relationships to one another.
Fundamental Design Principles for Transcription-Factor-Based Metabolite Biosensors.
Mannan, Ahmad A; Liu, Di; Zhang, Fuzhong; Oyarzún, Diego A
2017-10-20
Metabolite biosensors are central to current efforts toward precision engineering of metabolism. Although most research has focused on building new biosensors, their tunability remains poorly understood and is fundamental for their broad applicability. Here we asked how genetic modifications shape the dose-response curve of biosensors based on metabolite-responsive transcription factors. Using the lac system in Escherichia coli as a model system, we built promoter libraries with variable operator sites that reveal interdependencies between biosensor dynamic range and response threshold. We developed a phenomenological theory to quantify such design constraints in biosensors with various architectures and tunable parameters. Our theory reveals a maximal achievable dynamic range and exposes tunable parameters for orthogonal control of dynamic range and response threshold. Our work sheds light on fundamental limits of synthetic biology designs and provides quantitative guidelines for biosensor design in applications such as dynamic pathway control, strain optimization, and real-time monitoring of metabolism.
Höfener, Sebastian; Gomes, André Severo Pereira; Visscher, Lucas
2012-01-28
In this article, we present a consistent derivation of a density functional theory (DFT) based embedding method which encompasses wave-function theory-in-DFT (WFT-in-DFT) and the DFT-based subsystem formulation of response theory (DFT-in-DFT) by Neugebauer [J. Neugebauer, J. Chem. Phys. 131, 084104 (2009)] as special cases. This formulation, which is based on the time-averaged quasi-energy formalism, makes use of the variation Lagrangian techniques to allow the use of non-variational (in particular: coupled cluster) wave-function-based methods. We show how, in the time-independent limit, we naturally obtain expressions for the ground-state DFT-in-DFT and WFT-in-DFT embedding via a local potential. We furthermore provide working equations for the special case in which coupled cluster theory is used to obtain the density and excitation energies of the active subsystem. A sample application is given to demonstrate the method. © 2012 American Institute of Physics
Action Regulation Theory and Career Self-Management
ERIC Educational Resources Information Center
Raabe, Babette; Frese, Michael; Beehr, Terry A.
2007-01-01
Much of the responsibility for managing careers is shifting from employers to adaptive and proactive employees. A career management intervention based on action regulation theory trained 205 white collar employees to engage actively in their own career building by increasing their self-knowledge, career goal commitment, and career plan quality. As…
DYSLEXIA--IS THERE SUCH A THING.
ERIC Educational Resources Information Center
BOTEL, MORTON
THE THEORY OF DEVELOPMENTAL DYSLEXIA IS CONTRASTED WITH THE THEORY OF DEVELOPMENTAL IMMATURITY TO EXPLAIN EXTREME READING RETARDATION. DYSLEXIA IS DEFINED AS AN ORGANICALLY BASED READING DISABILITY WHICH IS DETERMINED INDIRECTLY SINCE NO ANATOMIC LESION, CHROMOSOME, OR GENE HAS YET BEEN FOUND RESPONSIBLE. DYSLEXIA IS USUALLY DEDUCED FROM (1)…
Beyond the Four Theories of the Press.
ERIC Educational Resources Information Center
Servaes, Jan
An examination of the interrelated philosophical, political, economic, and cultural dimensions of the four normative media theories (authoritarian, Soviet-communist, liberal, and social responsibility) in a societal context based on power relationships leads to four conclusions of a general nature. First, the media in one nation can have different…
He, Yongqun
2016-06-01
Compared with controlled terminologies ( e.g. , MedDRA, CTCAE, and WHO-ART), the community-based Ontology of AEs (OAE) has many advantages in adverse event (AE) classifications. The OAE-derived Ontology of Vaccine AEs (OVAE) and Ontology of Drug Neuropathy AEs (ODNAE) serve as AE knowledge bases and support data integration and analysis. The Immune Response Gene Network Theory explains molecular mechanisms of vaccine-related AEs. The OneNet Theory of Life treats the whole process of a life of an organism as a single complex and dynamic network ( i.e. , OneNet). A new "OneNet effectiveness" tenet is proposed here to expand the OneNet theory. Derived from the OneNet theory, the author hypothesizes that one human uses one single genotype-rooted mechanism to respond to different vaccinations and drug treatments, and experimentally identified mechanisms are manifestations of the OneNet blueprint mechanism under specific conditions. The theories and ontologies interact together as semantic frameworks to support integrative pharmacovigilance research.
ERIC Educational Resources Information Center
Samejima, Fumiko
2008-01-01
Samejima ("Psychometrika "65:319--335, 2000) proposed the logistic positive exponent family of models (LPEF) for dichotomous responses in the unidimensional latent space. The objective of the present paper is to propose and discuss a graded response model that is expanded from the LPEF, in the context of item response theory (IRT). This…
Asakura, Nobuhiko; Inui, Toshio
2016-01-01
Two apparently contrasting theories have been proposed to account for the development of children's theory of mind (ToM): theory-theory and simulation theory. We present a Bayesian framework that rationally integrates both theories for false belief reasoning. This framework exploits two internal models for predicting the belief states of others: one of self and one of others. These internal models are responsible for simulation-based and theory-based reasoning, respectively. The framework further takes into account empirical studies of a developmental ToM scale (e.g., Wellman and Liu, 2004): developmental progressions of various mental state understandings leading up to false belief understanding. By representing the internal models and their interactions as a causal Bayesian network, we formalize the model of children's false belief reasoning as probabilistic computations on the Bayesian network. This model probabilistically weighs and combines the two internal models and predicts children's false belief ability as a multiplicative effect of their early-developed abilities to understand the mental concepts of diverse beliefs and knowledge access. Specifically, the model predicts that children's proportion of correct responses on a false belief task can be closely approximated as the product of their proportions correct on the diverse belief and knowledge access tasks. To validate this prediction, we illustrate that our model provides good fits to a variety of ToM scale data for preschool children. We discuss the implications and extensions of our model for a deeper understanding of developmental progressions of children's ToM abilities. PMID:28082941
Asakura, Nobuhiko; Inui, Toshio
2016-01-01
Two apparently contrasting theories have been proposed to account for the development of children's theory of mind (ToM): theory-theory and simulation theory. We present a Bayesian framework that rationally integrates both theories for false belief reasoning. This framework exploits two internal models for predicting the belief states of others: one of self and one of others. These internal models are responsible for simulation-based and theory-based reasoning, respectively. The framework further takes into account empirical studies of a developmental ToM scale (e.g., Wellman and Liu, 2004): developmental progressions of various mental state understandings leading up to false belief understanding. By representing the internal models and their interactions as a causal Bayesian network, we formalize the model of children's false belief reasoning as probabilistic computations on the Bayesian network. This model probabilistically weighs and combines the two internal models and predicts children's false belief ability as a multiplicative effect of their early-developed abilities to understand the mental concepts of diverse beliefs and knowledge access. Specifically, the model predicts that children's proportion of correct responses on a false belief task can be closely approximated as the product of their proportions correct on the diverse belief and knowledge access tasks. To validate this prediction, we illustrate that our model provides good fits to a variety of ToM scale data for preschool children. We discuss the implications and extensions of our model for a deeper understanding of developmental progressions of children's ToM abilities.
Molecular Electron Density Theory: A Modern View of Reactivity in Organic Chemistry.
Domingo, Luis R
2016-09-30
A new theory for the study of the reactivity in Organic Chemistry, named Molecular Electron Density Theory (MEDT), is proposed herein. MEDT is based on the idea that while the electron density distribution at the ground state is responsible for physical and chemical molecular properties, as proposed by the Density Functional Theory (DFT), the capability for changes in electron density is responsible for molecular reactivity. Within MEDT, the reactivity in Organic Chemistry is studied through a rigorous quantum chemical analysis of the changes of the electron density as well as the energies associated with these changes along the reaction path in order to understand experimental outcomes. Studies performed using MEDT allow establishing a modern rationalisation and to gain insight into molecular mechanisms and reactivity in Organic Chemistry.
ERIC Educational Resources Information Center
Buchanan, Rebecca
2017-01-01
This dissertation investigates a perennial problem in teacher education: the theory-practice divide. There has always been a rift between theory and practice; however, this gap and the responses to it take on different shapes and meanings based on the reforms, politics, and structures of the time. For example, in the 1980s and 90s Professional…
Recent Applications of the Volterra Theory to Aeroelastic Phenomena
NASA Technical Reports Server (NTRS)
Silva, Walter A.; Haji, Muhammad R; Prazenica, Richard J.
2005-01-01
The identification of nonlinear aeroelastic systems based on the Volterra theory of nonlinear systems is presented. Recent applications of the theory to problems in experimental aeroelasticity are reviewed. These results include the identification of aerodynamic impulse responses, the application of higher-order spectra (HOS) to wind-tunnel flutter data, and the identification of nonlinear aeroelastic phenomena from flight flutter test data of the Active Aeroelastic Wing (AAW) aircraft.
Stochastical modeling for Viral Disease: Statistical Mechanics and Network Theory
NASA Astrophysics Data System (ADS)
Zhou, Hao; Deem, Michael
2007-04-01
Theoretical methods of statistical mechanics are developed and applied to study the immunological response against viral disease, such as dengue. We use this theory to show how the immune response to four different dengue serotypes may be sculpted. It is the ability of avian influenza, to change and to mix, that has given rise to the fear of a new human flu pandemic. Here we propose to utilize a scale free network based stochastic model to investigate the mitigation strategies and analyze the risk.
ERIC Educational Resources Information Center
Sleeter, Christine E., Ed.
2011-01-01
The work presented here is a large-scale evaluation of a theory-driven school reform project in New Zealand, which focuses on improving the educational achievement of Maori students in public secondary schools. The project's conceptual underpinnings are based on Kaupapa Maori research, culturally responsive teaching, student voice, and…
Linear-response time-dependent density-functional theory with pairing fields.
Peng, Degao; van Aggelen, Helen; Yang, Yang; Yang, Weitao
2014-05-14
Recent development in particle-particle random phase approximation (pp-RPA) broadens the perspective on ground state correlation energies [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013), Y. Yang, H. van Aggelen, S. N. Steinmann, D. Peng, and W. Yang, J. Chem. Phys. 139, 174110 (2013); D. Peng, S. N. Steinmann, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 104112 (2013)] and N ± 2 excitation energies [Y. Yang, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 224105 (2013)]. So far Hartree-Fock and approximated density-functional orbitals have been utilized to evaluate the pp-RPA equation. In this paper, to further explore the fundamentals and the potential use of pairing matrix dependent functionals, we present the linear-response time-dependent density-functional theory with pairing fields with both adiabatic and frequency-dependent kernels. This theory is related to the density-functional theory and time-dependent density-functional theory for superconductors, but is applied to normal non-superconducting systems for our purpose. Due to the lack of the proof of the one-to-one mapping between the pairing matrix and the pairing field for time-dependent systems, the linear-response theory is established based on the representability assumption of the pairing matrix. The linear response theory justifies the use of approximated density-functionals in the pp-RPA equation. This work sets the fundamentals for future density-functional development to enhance the description of ground state correlation energies and N ± 2 excitation energies.
Mehrkash, Milad; Azhari, Mojtaba; Mirdamadi, Hamid Reza
2014-01-01
The importance of elastic wave propagation problem in plates arises from the application of ultrasonic elastic waves in non-destructive evaluation of plate-like structures. However, precise study and analysis of acoustic guided waves especially in non-homogeneous waveguides such as functionally graded plates are so complicated that exact elastodynamic methods are rarely employed in practical applications. Thus, the simple approximate plate theories have attracted much interest for the calculation of wave fields in FGM plates. Therefore, in the current research, the classical plate theory (CPT), first-order shear deformation theory (FSDT) and third-order shear deformation theory (TSDT) are used to obtain the transient responses of flexural waves in FGM plates subjected to transverse impulsive loadings. Moreover, comparing the results with those based on a well recognized hybrid numerical method (HNM), we examine the accuracy of the plate theories for several plates of various thicknesses under excitations of different frequencies. The material properties of the plate are assumed to vary across the plate thickness according to a simple power-law distribution in terms of volume fractions of constituents. In all analyses, spatial Fourier transform together with modal analysis are applied to compute displacement responses of the plates. A comparison of the results demonstrates the reliability ranges of the approximate plate theories for elastic wave propagation analysis in FGM plates. Furthermore, based on various examples, it is shown that whenever the plate theories are used within the appropriate ranges of plate thickness and frequency content, solution process in wave number-time domain based on modal analysis approach is not only sufficient but also efficient for finding the transient waveforms in FGM plates. Copyright © 2013 Elsevier B.V. All rights reserved.
Pragmatic hydraulic theory predicts stomatal responses to climatic water deficits.
Sperry, John S; Wang, Yujie; Wolfe, Brett T; Mackay, D Scott; Anderegg, William R L; McDowell, Nate G; Pockman, William T
2016-11-01
Ecosystem models have difficulty predicting plant drought responses, partially from uncertainty in the stomatal response to water deficits in soil and atmosphere. We evaluate a 'supply-demand' theory for water-limited stomatal behavior that avoids the typical scaffold of empirical response functions. The premise is that canopy water demand is regulated in proportion to threat to supply posed by xylem cavitation and soil drying. The theory was implemented in a trait-based soil-plant-atmosphere model. The model predicted canopy transpiration (E), canopy diffusive conductance (G), and canopy xylem pressure (P canopy ) from soil water potential (P soil ) and vapor pressure deficit (D). Modeled responses to D and P soil were consistent with empirical response functions, but controlling parameters were hydraulic traits rather than coefficients. Maximum hydraulic and diffusive conductances and vulnerability to loss in hydraulic conductance dictated stomatal sensitivity and hence the iso- to anisohydric spectrum of regulation. The model matched wide fluctuations in G and P canopy across nine data sets from seasonally dry tropical forest and piñon-juniper woodland with < 26% mean error. Promising initial performance suggests the theory could be useful in improving ecosystem models. Better understanding of the variation in hydraulic properties along the root-stem-leaf continuum will simplify parameterization. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
ERIC Educational Resources Information Center
Fischer, Ronald G.; Fischer, Jerome M.
2006-01-01
Based on theories of emotional intelligence, adult education, psychology of reading, and emotions and literature, this study was designed to develop and validate the Affective Response to Literature Survey (ARLS), a psychological instrument used to measure an emotional response to literature. Initially, 27 items were generated by a review of…
A Danger-Theory-Based Immune Network Optimization Algorithm
Li, Tao; Xiao, Xin; Shi, Yuanquan
2013-01-01
Existing artificial immune optimization algorithms reflect a number of shortcomings, such as premature convergence and poor local search ability. This paper proposes a danger-theory-based immune network optimization algorithm, named dt-aiNet. The danger theory emphasizes that danger signals generated from changes of environments will guide different levels of immune responses, and the areas around danger signals are called danger zones. By defining the danger zone to calculate danger signals for each antibody, the algorithm adjusts antibodies' concentrations through its own danger signals and then triggers immune responses of self-regulation. So the population diversity can be maintained. Experimental results show that the algorithm has more advantages in the solution quality and diversity of the population. Compared with influential optimization algorithms, CLONALG, opt-aiNet, and dopt-aiNet, the algorithm has smaller error values and higher success rates and can find solutions to meet the accuracies within the specified function evaluation times. PMID:23483853
Compound cueing in free recall
Lohnas, Lynn J.; Kahana, Michael J.
2013-01-01
According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cueing in free recall. Specifically, the temporal contiguity effect should be greater when the two most recently recalled items were studied in contiguous list positions. A meta-analysis of published free recall experiments demonstrates evidence for compound cueing in both conditional response probabilities and inter-response times. To help rule out a rehearsal-based account of these compound cueing effects, we conducted an experiment with immediate, delayed and continual-distractor free recall conditions. Consistent with retrieved context theory but not with a rehearsal-based account, compound cueing was present in all conditions, and was not significantly influenced by the presence of interitem distractors. PMID:23957364
Implicit theories of writing and their impact on students' response to a SRSD intervention.
Limpo, Teresa; Alves, Rui A
2014-12-01
In the field of intelligence research, it has been shown that some people conceive intelligence as a fixed trait that cannot be changed (entity beliefs), whereas others conceive it as a malleable trait that can be developed (incremental beliefs). What about writing? Do people hold similar implicit theories about the nature of their writing ability? Furthermore, are these beliefs likely to influence students' response to a writing intervention? We aimed to develop a scale to measure students' implicit theories of writing (pilot study) and to test whether these beliefs influence strategy-instruction effectiveness (intervention study). In the pilot and intervention studies participated, respectively, 128 and 192 students (Grades 5-6). Based on existing instruments that measure self-theories of intelligence, we developed the Implicit Theories of Writing (ITW) scale that was tested with the pilot sample. In the intervention study, 109 students received planning instruction based on the self-regulated strategy development model, whereas 83 students received standard writing instruction. Students were evaluated before, in the middle, and after instruction. ITW's validity was supported by piloting results and their successful cross-validation in the intervention study. In this, intervention students wrote longer and better texts than control students. Moreover, latent growth curve modelling showed that the more the intervention students conceived writing as a malleable skill, the more the quality of their texts improved. This research is of educational relevance because it provides a measure to evaluate students' implicit theories of writing and shows their impact on response to intervention. © 2014 The British Psychological Society.
Macmillan, N A; Creelman, C D
1996-06-01
Can accuracy and response bias in two-stimulus, two-response recognition or detection experiments be measured nonparametrically? Pollack and Norman (1964) answered this question affirmatively for sensitivity, Hodos (1970) for bias: Both proposed measures based on triangular areas in receiver-operating characteristic space. Their papers, and especially a paper by Grier (1971) that provided computing formulas for the measures, continue to be heavily cited in a wide range of content areas. In our sample of articles, most authors described triangle-based measures as making fewer assumptions than measures associated with detection theory. However, we show that statistics based on products or ratios of right triangle areas, including a recently proposed bias index and a not-yetproposed but apparently plausible sensitivity index, are consistent with a decision process based on logistic distributions. Even the Pollack and Norman measure, which is based on non-right triangles, is approximately logistic for low values of sensitivity. Simple geometric models for sensitivity and bias are not nonparametric, even if their implications are not acknowledged in the defining publications.
A simplified orthotropic formulation of the viscoplasticity theory based on overstress
NASA Technical Reports Server (NTRS)
Sutcu, M.; Krempl, E.
1988-01-01
An orthotropic, small strain viscoplasticity theory based on overstress is presented. In each preferred direction the stress is composed of time (rate) independent (or plastic) and viscous (or rate dependent) contributions. Tension-compression asymmetry can depend on direction and is included in the model. Upon a proper choice of a material constant one preferred direction can exhibit linear elastic response while the other two deform in a viscoplastic manner.
Lambert, Michael Canute; Ferguson, Gail M; Rowan, George T
2016-03-01
Cross-national study of adolescents' psychological adjustment requires measures that permit reliable and valid assessment across informants and nations, but such measures are virtually nonexistent. Item-response-theory-based linking is a promising yet underutilized methodological procedure that permits more accurate assessment across informants and nations. To demonstrate this procedure, the Resilience Scale of the Behavioral Assessment for Children of African Heritage (Lambert et al., 2005) was administered to 250 African American and 294 Jamaican nonreferred adolescents and their caregivers. Multiple items without significant differential item functioning emerged, allowing scale linking across informants and nations. Calibrating item parameters via item response theory linking can permit cross-informant cross-national assessment of youth. (c) 2016 APA, all rights reserved).
Study on corporate social responsibility evaluation system based on stakeholder theory
NASA Astrophysics Data System (ADS)
Ma, J.; Deng, Liming
2011-10-01
The issue of Corporate Social Responsibility (CSR) has been attracting the attention from many disciplines such as economics, management, laws, sociality and philosophy since last century. The purpose of this study is to explore the impact of CSR on performance and develop a CSR evaluation system. Building on the definition of CSR and Stakeholder theory, this article built a path-relationship model of CSR and business operation performance. The paper also constructed CSR evaluation system based on KLD index, GRJ report, CSR accounting account, SA8000, ISO14000 etc. The research provides a basis for future studies about the relationship between CSR and business performance and shed some light on the evaluation of CSR practices.
NASA Astrophysics Data System (ADS)
Akbarzadeh Khorshidi, M.; Shariati, M.
2017-07-01
The elastic buckling analysis and the static postbuckling response of the Euler-Bernoulli microbeams containing an open edge crack are studied based on a modified couple stress theory. The cracked section is modeled by a massless elastic rotational spring. This model contains a material length scale parameter and can capture the size effect. The von Kármán nonlinearity is applied to display the postbuckling behavior. Analytical solutions of a critical buckling load and the postbuckling response are presented for simply supported cracked microbeams. This parametric study indicates the effects of the crack location, crack severity, and length scale parameter on the buckling and postbuckling behaviors of cracked microbeams.
Optimal resource allocation for novelty detection in a human auditory memory.
Sinkkonen, J; Kaski, S; Huotilainen, M; Ilmoniemi, R J; Näätänen, R; Kaila, K
1996-11-04
A theory of resource allocation for neuronal low-level filtering is presented, based on an analysis of optimal resource allocation in simple environments. A quantitative prediction of the theory was verified in measurements of the magnetic mismatch response (MMR), an auditory event-related magnetic response of the human brain. The amplitude of the MMR was found to be directly proportional to the information conveyed by the stimulus. To the extent that the amplitude of the MMR can be used to measure resource usage by the auditory cortex, this finding supports our theory that, at least for early auditory processing, energy resources are used in proportion to the information content of incoming stimulus flow.
Evaluating Cognitive Theory: A Joint Modeling Approach Using Responses and Response Times
ERIC Educational Resources Information Center
Klein Entink, Rinke H.; Kuhn, Jorg-Tobias; Hornke, Lutz F.; Fox, Jean-Paul
2009-01-01
In current psychological research, the analysis of data from computer-based assessments or experiments is often confined to accuracy scores. Response times, although being an important source of additional information, are either neglected or analyzed separately. In this article, a new model is developed that allows the simultaneous analysis of…
Accumulating Evidence about What Prospective Memory Costs Actually Reveal
ERIC Educational Resources Information Center
Strickland, Luke; Heathcote, Andrew; Remington, Roger W.; Loft, Shayne
2017-01-01
Event-based prospective memory (PM) tasks require participants to substitute an atypical PM response for an ongoing task response when presented with PM targets. Responses to ongoing tasks are often slower with the addition of PM demands ("PM costs"). Prominent PM theories attribute costs to capacity-sharing between the ongoing and PM…
Working with Sparse Data in Rated Language Tests: Generalizability Theory Applications
ERIC Educational Resources Information Center
Lin, Chih-Kai
2017-01-01
Sparse-rated data are common in operational performance-based language tests, as an inevitable result of assigning examinee responses to a fraction of available raters. The current study investigates the precision of two generalizability-theory methods (i.e., the rating method and the subdividing method) specifically designed to accommodate the…
ERIC Educational Resources Information Center
Lee, Robert E.; Creasey, Gary; Showalter, Brent D.; D'Santiago, Verenice
2010-01-01
Identifying (and assessing) the mechanisms responsible for promoting social justice awareness represent a process that could be illuminated via theory building. To illustrate, integrated theories of moral reasoning and prosocial development stipulate that ultimate altruistic/benevolent intentions and behaviors are preceded by cognitive and…
Scoring and Classifying Examinees Using Measurement Decision Theory
ERIC Educational Resources Information Center
Rudner, Lawrence M.
2009-01-01
This paper describes and evaluates the use of measurement decision theory (MDT) to classify examinees based on their item response patterns. The model has a simple framework that starts with the conditional probabilities of examinees in each category or mastery state responding correctly to each item. The presented evaluation investigates: (1) the…
ERIC Educational Resources Information Center
Wetzel, Eunike; Hell, Benedikt
2014-01-01
Vocational interest inventories are commonly analyzed using a unidimensional approach, that is, each subscale is analyzed separately. However, the theories on which these inventories are based often postulate specific relationships between the interest traits. This article presents a multidimensional approach to the analysis of vocational interest…
Preparing the Host Country Workforce for Expatriate Managers: The Neglected Other Side of the Coin.
ERIC Educational Resources Information Center
Vance, Charles M.; Ring, Peter Smith
1994-01-01
Using an instructional systems development approach, ways to prepare the host country workforce for the assignment of an expatriate manager are discussed. The model is based on a number of perspectives: exchange theory, participatory management, corporate social responsibility, communication theory, and strategic human resource planning. (SK)
Typologies for Effectiveness: Characteristics of Effective Teachers in Urban Learning Environments
ERIC Educational Resources Information Center
Robinson, Derrick; Lewis, Chance W.
2017-01-01
Despite increasing diversity in U.S. schools, the topic of teacher effectiveness remains to be dominated by a universal narrative. This study applies critical theory, critical race theory, and culturally responsive pedagogy to position teacher effectiveness as contextual to urban schools and relational to the asset-based view of the learner. This…
Testing the Theory of Embodied Cognition with Subliminal Words
ERIC Educational Resources Information Center
Ansorge, Ulrich; Kiefer, Marcus; Khalid, Shah; Grassl, Sylvia; Konig, Peter
2010-01-01
In the current study, we tested the embodied cognition theory (ECT). The ECT postulates mandatory sensorimotor processing of words when accessing their meaning. We test that prediction by investigating whether invisible (i.e., subliminal) spatial words activate responses based on their long-term and short-term meaning. Masking of the words is used…
NASA Astrophysics Data System (ADS)
Zhen, Wu; Wanji, Chen
2007-05-01
Buckling response of angle-ply laminated composite and sandwich plates are analyzed using the global-local higher order theory with combination of geometric stiffness matrix in this paper. This global-local theory completely fulfills the free surface conditions and the displacement and stress continuity conditions at interfaces. Moreover, the number of unknowns in this theory is independent of the number of layers in the laminate. Based on this global-local theory, a three-noded triangular element satisfying C1 continuity conditions has also been proposed. The bending part of this element is constructed from the concept of DKT element. In order to improve the accuracy of the analysis, a method of modified geometric stiffness matrix has been introduced. Numerical results show that the present theory not only computes accurately the buckling response of general laminated composite plates but also predicts the critical buckling loads of soft-core sandwiches. However, the global higher-order theories as well as first order theories might encounter some difficulties and overestimate the critical buckling loads for soft-core sandwich plates.
Carton, J S
1996-01-01
Substantial research indicates that tangible rewards, such as money, prizes, and tokens, decrease response rates by undermining intrinsic motivation. In contrast, praise appears to increase response rates by enhancing intrinsic motivation. Based on their interpretation of available evidence, many social-cognitive researchers warn not to use tangible rewards in applied settings and to use praise instead. Furthermore, they suggest that the differential effects of the two types of rewards on intrinsic motivation cannot be explained using principles of operant psychology. Cognitive evaluation theory provides one of the most recent and widely cited social-cognitive explanations for the different effects of the two types of rewards on intrinsic motivation (Deci & Ryan, 1985). However, a review of existing research found little support for the explanations based on this theory and revealed three potential confounding effects: (a) temporal contiguity, (b) the number of reward administrations, and (c) discriminative stimuli associated with reward availability. These three confounding factors provide explanations for the effects of tangible rewards and praise on intrinsic motivation that are consistent with principles of operant psychology.
Carton, John S.
1996-01-01
Substantial research indicates that tangible rewards, such as money, prizes, and tokens, decrease response rates by undermining intrinsic motivation. In contrast, praise appears to increase response rates by enhancing intrinsic motivation. Based on their interpretation of available evidence, many social-cognitive researchers warn not to use tangible rewards in applied settings and to use praise instead. Furthermore, they suggest that the differential effects of the two types of rewards on intrinsic motivation cannot be explained using principles of operant psychology. Cognitive evaluation theory provides one of the most recent and widely cited social-cognitive explanations for the different effects of the two types of rewards on intrinsic motivation (Deci & Ryan, 1985). However, a review of existing research found little support for the explanations based on this theory and revealed three potential confounding effects: (a) temporal contiguity, (b) the number of reward administrations, and (c) discriminative stimuli associated with reward availability. These three confounding factors provide explanations for the effects of tangible rewards and praise on intrinsic motivation that are consistent with principles of operant psychology. PMID:22478261
Design guide for predicting nonlinear random response (including snap-through) of buckled plates
NASA Technical Reports Server (NTRS)
Ng, Chung Fai
1989-01-01
This design guide describes a method for predicting the random response of flat and curved plates which is based on theoretical analyses and experimental results. The plate curvature can be due to postbuckling, in-plane mechanical or thermal stresses. Based on a single mode formula, root mean square values of the strain response to broadband excitation are evaluated for different static buckled configurations using the equivalent linearization technique. The effects on the overall strain response due to instability motion of snap-through are included. Panel parameters include clamped and simply-supported boundaries, aspect ratio, thickness and length. Analytical results are compared with experimental results from tests with 12 in. x 15 in. aluminum plates under thermal loading in a progressive wave facility. Comparisons are also made with results from tests with a 2 in. x 15 in. x 0.032 in. aluminum beam under base mechanical excitation. The comparisons help to assess the accuracy of the theory and the conditions under which deviations from the theory due to effects of imperfection and higher modes are significant.
Sullivan-Bolyai, Susan; Johnson, Kimberly; Cullen, Karen; Hamm, Terry; Bisordi, Jean; Blaney, Kathleen; Maguire, Laura; Melkus, Gail
2014-01-01
Parents become emotionally upset when learning their child has Type 1 Diabetes, yet they are expected to quickly learn functional diabetes management. The purpose of this article is to describe the application of Self-Regulation theory to guide a family-focused education intervention using human patient simulation to enhance the initial education of parents in diabetes management. A brief description is provided of the intervention framed by Self-Regulation theory. Based on the literature, we describe the educational vignettes used based on Self-Regulation in the randomized controlled trial entitled Parent Education Through Simulation-Diabetes. Examples of theory-in-practice will be illustrated by parental learning responses to this alternative educational innovation. PMID:25365286
NASA Technical Reports Server (NTRS)
Macfarlane, J. J.; Hubbard, W. B.
1983-01-01
A numerical technique for solving the Thomas-Fermi-Dirac (TED) equation in three dimensions, for an array of ions obeying periodic boundary conditions, is presented. The technique is then used to calculate deviations from ideal mixing for an alloy of hydrogen and helium at zero temperature and high presures. Results are compared with alternative models which apply perturbation theory to calculation of the electron distribution, based upon the assumption of weak response of the electron gas to the ions. The TFD theory, which permits strong electron response, always predicts smaller deviations from ideal mixing than would be predicted by perturbation theory. The results indicate that predicted phase separation curves for hydrogen-helium alloys under conditions prevailing in the metallic zones of Jupiter and Saturn are very model dependent.
Eriksen, Janus J; Sauer, Stephan P A; Mikkelsen, Kurt V; Jensen, Hans J Aa; Kongsted, Jacob
2012-09-30
We investigate the effect of including a dynamic reaction field at the lowest possible ab inito wave function level of theory, namely the Hartree-Fock (HF) self-consistent field level within the polarizable embedding (PE) formalism. We formulate HF based PE within the linear response theory picture leading to the PE-random-phase approximation (PE-RPA) and bridge the expressions to a second-order polarization propagator approximation (SOPPA) frame such that dynamic reaction field contributions are included at the RPA level in addition to the static response described at the SOPPA level but with HF induced dipole moments. We conduct calculations on para-nitro-aniline and para-nitro-phenolate using said model in addition to dynamic PE-RPA and PE-CAM-B3LYP. We compare the results to recently published PE-CCSD data and demonstrate how the cost effective SOPPA-based model successfully recovers a great portion of the inherent PE-RPA error when the observable is the solvatochromic shift. We furthermore demonstrate that whenever the change in density resulting from the ground state-excited state electronic transition in the solute is not associated with a significant change in the electric field, dynamic response contributions formulated at the HF level of theory manage to capture the majority of the system response originating from derivative densities. Copyright © 2012 Wiley Periodicals, Inc.
Tang, Yue; Zhang, Zhidong; Wang, Ruibing; Hai, Zhenyin; Xue, Chenyang; Zhang, Wendong; Yan, Shubin
2017-04-06
A surface plasmon polariton refractive index sensor based on Fano resonances in metal-insulator-metal (MIM) waveguides coupled with rectangular and ring resonators is proposed and numerically investigated using a finite element method. Fano resonances are observed in the transmission spectra, which result from the coupling between the narrow-band spectral response in the ring resonator and the broadband spectral response in the rectangular resonator. Results are analyzed using coupled-mode theory based on transmission line theory. The coupled mode theory is employed to explain the Fano resonance effect, and the analytical result is in good agreement with the simulation result. The results show that with an increase in the refractive index of the fill dielectric material in the slot of the system, the Fano resonance peak exhibits a remarkable red shift, and the highest value of sensitivity (S) is 1125 nm/RIU, RIU means refractive index unit. Furthermore, the coupled MIM waveguide structure can be integrated with other photonic devices at the chip scale. The results can provide a guide for future applications of this structure.
Semiclassical Path Integral Calculation of Nonlinear Optical Spectroscopy.
Provazza, Justin; Segatta, Francesco; Garavelli, Marco; Coker, David F
2018-02-13
Computation of nonlinear optical response functions allows for an in-depth connection between theory and experiment. Experimentally recorded spectra provide a high density of information, but to objectively disentangle overlapping signals and to reach a detailed and reliable understanding of the system dynamics, measurements must be integrated with theoretical approaches. Here, we present a new, highly accurate and efficient trajectory-based semiclassical path integral method for computing higher order nonlinear optical response functions for non-Markovian open quantum systems. The approach is, in principle, applicable to general Hamiltonians and does not require any restrictions on the form of the intrasystem or system-bath couplings. This method is systematically improvable and is shown to be valid in parameter regimes where perturbation theory-based methods qualitatively breakdown. As a test of the methodology presented here, we study a system-bath model for a coupled dimer for which we compare against numerically exact results and standard approximate perturbation theory-based calculations. Additionally, we study a monomer with discrete vibronic states that serves as the starting point for future investigation of vibronic signatures in nonlinear electronic spectroscopy.
He, Yongqun
2016-01-01
Compared with controlled terminologies (e.g., MedDRA, CTCAE, and WHO-ART), the community-based Ontology of AEs (OAE) has many advantages in adverse event (AE) classifications. The OAE-derived Ontology of Vaccine AEs (OVAE) and Ontology of Drug Neuropathy AEs (ODNAE) serve as AE knowledge bases and support data integration and analysis. The Immune Response Gene Network Theory explains molecular mechanisms of vaccine-related AEs. The OneNet Theory of Life treats the whole process of a life of an organism as a single complex and dynamic network (i.e., OneNet). A new “OneNet effectiveness” tenet is proposed here to expand the OneNet theory. Derived from the OneNet theory, the author hypothesizes that one human uses one single genotype-rooted mechanism to respond to different vaccinations and drug treatments, and experimentally identified mechanisms are manifestations of the OneNet blueprint mechanism under specific conditions. The theories and ontologies interact together as semantic frameworks to support integrative pharmacovigilance research. PMID:27458549
Ziegler, Tom; Krykunov, Mykhaylo
2010-08-21
It is well known that time-dependent density functional theory (TD-DFT) based on standard gradient corrected functionals affords both a quantitative and qualitative incorrect picture of charge transfer transitions between two spatially separated regions. It is shown here that the well known failure can be traced back to the use of linear response theory. Further, it is demonstrated that the inclusion of higher order terms readily affords a qualitatively correct picture even for simple functionals based on the local density approximation. The inclusion of these terms is done within the framework of a newly developed variational approach to excitation energies called constrained variational density functional theory (CV-DFT). To second order [CV(2)-DFT] this theory is identical to adiabatic TD-DFT within the Tamm-Dancoff approximation. With inclusion of fourth order corrections [CV(4)-DFT] it affords a qualitative correct description of charge transfer transitions. It is finally demonstrated that the relaxation of the ground state Kohn-Sham orbitals to first order in response to the change in density on excitation together with CV(4)-DFT affords charge transfer excitations in good agreement with experiment. The new relaxed theory is termed R-CV(4)-DFT. The relaxed scheme represents an effective way in which to introduce double replacements into the description of single electron excitations, something that would otherwise require a frequency dependent kernel.
NASA Astrophysics Data System (ADS)
Presti, Giovambattista; Messina, Concetta; Mongelli, Francesca; Sireci, Maria Josè; Collotta, Mario
2017-11-01
Relational Frame Theory is a post-skinnerian theory of language and cognition based on more than thirty years of basic and applied research. It defines language and cognitive skills as an operant repertoire of responses to arbitrarily related stimuli specific, as far as is now known, of the human species. RFT has been proved useful in addressing cognitive barriers to human action in psychotherapy and also improving children skills in reading, IQ testing, and in metaphoric and categorical repertoires. We present a frame of action where RFT can be used in programming software to help autistic children to develop cognitive skills within a developmental vision.
Quality Management in Hungarian Higher Education: Organisational Responses to Governmental Policy
ERIC Educational Resources Information Center
Csizmadia, Tibor; Enders, Jurgen; Westerheijden, Don F.
2008-01-01
This article focuses on responses of higher education institutions to governmental policy. We investigate the influence of organisational characteristics on the implementation of quality management in Hungarian higher education institutions. Our theoretical framework is based on organisational theories (resource dependency and…
Profile-likelihood Confidence Intervals in Item Response Theory Models.
Chalmers, R Philip; Pek, Jolynn; Liu, Yang
2017-01-01
Confidence intervals (CIs) are fundamental inferential devices which quantify the sampling variability of parameter estimates. In item response theory, CIs have been primarily obtained from large-sample Wald-type approaches based on standard error estimates, derived from the observed or expected information matrix, after parameters have been estimated via maximum likelihood. An alternative approach to constructing CIs is to quantify sampling variability directly from the likelihood function with a technique known as profile-likelihood confidence intervals (PL CIs). In this article, we introduce PL CIs for item response theory models, compare PL CIs to classical large-sample Wald-type CIs, and demonstrate important distinctions among these CIs. CIs are then constructed for parameters directly estimated in the specified model and for transformed parameters which are often obtained post-estimation. Monte Carlo simulation results suggest that PL CIs perform consistently better than Wald-type CIs for both non-transformed and transformed parameters.
Enhanced embodied response following ambiguous emotional processing.
Beffara, Brice; Ouellet, Marc; Vermeulen, Nicolas; Basu, Anamitra; Morisseau, Tiffany; Mermillod, Martial
2012-08-01
It has generally been assumed that high-level cognitive and emotional processes are based on amodal conceptual information. In contrast, however, "embodied simulation" theory states that the perception of an emotional signal can trigger a simulation of the related state in the motor, somatosensory, and affective systems. To study the effect of social context on the mimicry effect predicted by the "embodied simulation" theory, we recorded the electromyographic (EMG) activity of participants when looking at emotional facial expressions. We observed an increase in embodied responses when the participants were exposed to a context involving social valence before seeing the emotional facial expressions. An examination of the dynamic EMG activity induced by two socially relevant emotional expressions (namely joy and anger) revealed enhanced EMG responses of the facial muscles associated with the related social prime (either positive or negative). These results are discussed within the general framework of embodiment theory.
ERIC Educational Resources Information Center
Sampson, James P., Jr.; Peterson, Gary W.; Reardon, Robert C.; Lenz, Janet G.
2000-01-01
Responds to Jepsen's (this issue [2000]) commentary on Sampson et al.'s theory-based approach to using readiness assessment to improve career services. Three topics are included: the reliability and utility of using readiness assessment measures; verbal ability and the use of cognitive information-processing theory in practice; and the potential…
Profiling Differences in Achievement and Social Goals of Students at Different Levels of Expertise
ERIC Educational Resources Information Center
O'Malley, Patricia Tenowich; Sonnenschein, Susan
2010-01-01
The purpose of this study was to integrate domain-learning theory and goal theory to investigate the learning processes, achievement goals, social goals, and achievement of 141 college students. Cluster-analytic procedures were used to categorize participants at different levels of expertise based on their responses on knowledge, interest, and…
ERIC Educational Resources Information Center
Dahlvig, Jolyn; Longman, Karen A.
2014-01-01
A theory of women's leadership development within the context of Christian higher education is proposed, based on qualitative research involving 16 participants. Motivators to advance into leadership roles were: (a) a sense of relational responsibility; (b) awareness of calling and giftedness for leadership, and (c) a mentoring relationship…
ERIC Educational Resources Information Center
Chinn, Pauline W. U.
2011-01-01
This response to Mitchell and Mueller's "A philosophical analysis of David Orr's theory of ecological literacy" comments on their critique of Orr's use of the phrase "ecological crisis" and what I perceive as their conflicting views of "crisis." I present my views on ecological crisis informed by standpoint theory and…
Social response to technological disaster: the accident at Three Mile Island
DOE Office of Scientific and Technical Information (OSTI.GOV)
Richardson, B.B.
1984-01-01
Until recently the sociological study of man environment relations under extreme circumstances has been restricted to natural hazards (e.g., floods, hurricanes, tornadoes). Technological disasters are becoming more commonplace (e.g., Times Beach, MO, Love Canal, TMI-2) and are growing as potential sources of impact upon human populations. However, theory regarding the social impact of such disasters has not been developed. While research on natural disasters is in part applicable to technological disasters, theory adapted from environmental sociology and psychology are also utilized to develop a theory of social response to extreme environmental events produced by technology. Hypotheses are developed in themore » form of an empirically testable model based on the literature reviewed.« less
Structure and Measurement of Depression in Youth: Applying Item Response Theory to Clinical Data
Cole, David A.; Cai, Li; Martin, Nina C.; Findling, Robert L; Youngstrom, Eric A.; Garber, Judy; Curry, John F.; Hyde, Janet S.; Essex, Marilyn J.; Compas, Bruce E.; Goodyer, Ian M.; Rohde, Paul; Stark, Kevin D.; Slattery, Marcia J.; Forehand, Rex
2013-01-01
Goals of the paper were to use item response theory (IRT) to assess the relation of depressive symptoms to the underlying dimension of depression and to demonstrate how IRT-based measurement strategies can yield more reliable data about depression severity than conventional symptom counts. Participants were 3403 clinic and nonclinic children and adolescents from 12 contributing samples, all of whom received the Kiddie Schedule of Affective Disorders and Schizophrenia for school-aged children. Results revealed that some symptoms reflected higher levels of depression and were more discriminating than others. Results further demonstrated that utilization of IRT-based information about symptom severity and discriminability in the measurement of depression severity can reduce measurement error and increase measurement fidelity. PMID:21534696
Leblanc, Vicky; Bégin, Catherine; Hudon, Anne-Marie; Royer, Marie-Michelle; Corneau, Louise; Dodin, Sylvie; Lemieux, Simone
2016-01-01
Our objective was to determine gender differences in the impact of a nutritional intervention based on the self-determination theory and promoting the Mediterranean diet on changes in eating-related self-determined motivation and adherence to the Mediterranean diet. Changes in eating-related self-determined motivation were larger in men than in women in response to the intervention and at follow-up, but the magnitude of change decreased with time in both genders. Changes in eating-related self-determined motivation were positively associated with changes in the Mediterranean diet adherence in response to the intervention and at follow-up in men only, suggesting that the nutritional program seems to fit better men than women.
Leblanc, Vicky; Bégin, Catherine; Hudon, Anne-Marie; Royer, Marie-Michelle; Corneau, Louise; Dodin, Sylvie; Lemieux, Simone
2016-01-01
Our objective was to determine gender differences in the impact of a nutritional intervention based on the self-determination theory and promoting the Mediterranean diet on changes in eating-related self-determined motivation and adherence to the Mediterranean diet. Changes in eating-related self-determined motivation were larger in men than in women in response to the intervention and at follow-up, but the magnitude of change decreased with time in both genders. Changes in eating-related self-determined motivation were positively associated with changes in the Mediterranean diet adherence in response to the intervention and at follow-up in men only, suggesting that the nutritional program seems to fit better men than women. PMID:28070382
Li, Xiaoming; Lin, Danhua; Wang, Bo; Du, Hongfei; Tam, Cheuk Chi; Stanton, Bonita
2014-08-01
Our objective was to evaluate the efficacy of a cultural adaptation of a social cognitive theory-based HIV behavioral prevention program among young rural-to-urban migrants in China. The intervention design and assessment were guided by the Protection Motivation Theory (PMT). The intervention was evaluated through a randomized controlled trial with 6-month and 12-month follow-ups. The primary behavioral outcome was the use of condoms. Other outcome measures include HIV knowledge, condom use knowledge, HIV-related perceptions (PMT constructs), and intention to use condom. The mixed-effects regression models for condom use with regular partners indicated that overall frequency of condom use, condom use in last three sexual acts and proper condom use increased over time for the participants but the increases were significantly greater among the intervention group than the control group at 6-month and 12-month follow-ups. The mixed-effects models for HIV-related perceptions indicated that extrinsic rewards, intrinsic rewards, and response costs decreased while vulnerability, severity, response efficacy, and self-efficacy increased over time for the intervention group. The increases in HIV knowledge, condom use knowledge, and intention to use condom were also significantly greater among the intervention group than the control group. The data in the current study suggested efficacy of a social cognitive theory-based behavioral intervention in increasing condom use among young migrants in China. The intervention also increased protective perceptions and decreased risk perception posited by the theory (i.e., PMT).
Regulatory implications of a linear non-threshold (LNT) dose-based risks.
Aleta, C R
2009-01-01
Current radiation protection regulatory limits are based on the linear non-threshold (LNT) theory using health data from atomic bombing survivors. Studies in recent years sparked debate on the validity of the theory, especially at low doses. The present LNT overestimates radiation risks since the dosimetry included only acute gammas and neutrons; the role of other bomb-caused factors, e.g. fallout, induced radioactivity, thermal radiation (UVR), electromagnetic pulse (EMP), and blast, were excluded. Studies are proposed to improve the dose-response relationship.
The Determinants of Medical Tourism Intentions: Applying the Theory of Planned Behavior.
Ramamonjiarivelo, Zo; Martin, David S; Martin, Warren S
2015-01-01
This study introduces the theory of planned behavior to health care marketers by extending and replicating a prior study that predicted student's intention to engage in medical tourism. Based on a sample of 164 usable survey responses, our findings suggested that the MEDTOUR scale (developed and introduced a prior study) is robust and works reasonably well with a national sample. Based on these findings, MEDTOUR appears to be worthy of further consideration by health marketing scholars.
ERIC Educational Resources Information Center
Svetina, Dubravka
2013-01-01
The purpose of this study was to investigate the effect of complex structure on dimensionality assessment in noncompensatory multidimensional item response models using dimensionality assessment procedures based on DETECT (dimensionality evaluation to enumerate contributing traits) and NOHARM (normal ogive harmonic analysis robust method). Five…
NASA Technical Reports Server (NTRS)
Stein, Manuel; Sydow, P. Daniel; Librescu, Liviu
1990-01-01
Buckling and postbuckling results are presented for compression-loaded simply-supported aluminum plates and composite plates with a symmetric lay-up of thin + or - 45 deg plies composed of many layers. Buckling results for aluminum plates of finite length are given for various length-to-width ratios. Asymptotes to the curves based on buckling results give N(sub xcr) for plates of infinite length. Postbuckling results for plates with transverse shearing flexibility are compared to results from classical theory for various width-to-thickness ratios. Characteristic curves indicating the average longitudinal direct stress resultant as a function of the applied displacements are calculated based on four different theories: Classical von Karman theory using the Kirchoff assumptions, first-order shear deformation theory, higher-order shear deformation theory, and 3-D flexibility theory. Present results indicate that the 3-D flexibility theory gives the lowest buckling loads. The higher-order shear deformation theory has fewer unknowns than the 3-D flexibility theory but does not take into account through-the-thickness effects. The figures presented show that small differences occur in the average longitudinal direct stress resultants from the four theories that are functions of applied end-shortening displacement.
NASA Astrophysics Data System (ADS)
Rezaei Kivi, Araz; Azizi, Saber; Norouzi, Peyman
2017-12-01
In this paper, the nonlinear size-dependent static and dynamic behavior of an electrostatically actuated nano-beam is investigated. A fully clamped nano-beam is considered for the modeling of the deformable electrode of the NEMS. The governing differential equation of the motion is derived using Hamiltonian principle based on couple stress theory; a non-classical theory for considering length scale effects. The nonlinear partial differential equation of the motion is discretized to a nonlinear Duffing type ODE's using Galerkin method. Static and dynamic pull-in instabilities obtained by both classical theory and MCST are compared. At the second stage of analysis, shooting technique is utilized to obtain the frequency response curve, and to capture the periodic solutions of the motion; the stability of the periodic solutions are gained by Floquet theory. The nonlinear dynamic behavior of the deformable electrode due to the AC harmonic accompanied with size dependency is investigated.
Excited states with internally contracted multireference coupled-cluster linear response theory.
Samanta, Pradipta Kumar; Mukherjee, Debashis; Hanauer, Matthias; Köhn, Andreas
2014-04-07
In this paper, the linear response (LR) theory for the variant of internally contracted multireference coupled cluster (ic-MRCC) theory described by Hanauer and Köhn [J. Chem. Phys. 134, 204211 (2011)] has been formulated and implemented for the computation of the excitation energies relative to a ground state of pronounced multireference character. We find that straightforward application of the linear-response formalism to the time-averaged ic-MRCC Lagrangian leads to unphysical second-order poles. However, the coupling matrix elements that cause this behavior are shown to be negligible whenever the internally contracted approximation as such is justified. Hence, for the numerical implementation of the method, we adopt a Tamm-Dancoff-type approximation and neglect these couplings. This approximation is also consistent with an equation-of-motion based derivation, which neglects these couplings right from the start. We have implemented the linear-response approach in the ic-MRCC singles-and-doubles framework and applied our method to calculate excitation energies for a number of molecules ranging from CH2 to p-benzyne and conjugated polyenes (up to octatetraene). The computed excitation energies are found to be very accurate, even for the notoriously difficult case of doubly excited states. The ic-MRCC-LR theory is also applicable to systems with open-shell ground-state wavefunctions and is by construction not biased towards a particular reference determinant. We have also compared the linear-response approach to the computation of energy differences by direct state-specific ic-MRCC calculations. We finally compare to Mk-MRCC-LR theory for which spurious roots have been reported [T.-C. Jagau and J. Gauss, J. Chem. Phys. 137, 044116 (2012)], being due to the use of sufficiency conditions to solve the Mk-MRCC equations. No such problem is present in ic-MRCC-LR theory.
Equal Area Logistic Estimation for Item Response Theory
NASA Astrophysics Data System (ADS)
Lo, Shih-Ching; Wang, Kuo-Chang; Chang, Hsin-Li
2009-08-01
Item response theory (IRT) models use logistic functions exclusively as item response functions (IRFs). Applications of IRT models require obtaining the set of values for logistic function parameters that best fit an empirical data set. However, success in obtaining such set of values does not guarantee that the constructs they represent actually exist, for the adequacy of a model is not sustained by the possibility of estimating parameters. In this study, an equal area based two-parameter logistic model estimation algorithm is proposed. Two theorems are given to prove that the results of the algorithm are equivalent to the results of fitting data by logistic model. Numerical results are presented to show the stability and accuracy of the algorithm.
Using Necessary Information to Identify Item Dependence in Passage-Based Reading Comprehension Tests
ERIC Educational Resources Information Center
Baldonado, Angela Argo; Svetina, Dubravka; Gorin, Joanna
2015-01-01
Applications of traditional unidimensional item response theory models to passage-based reading comprehension assessment data have been criticized based on potential violations of local independence. However, simple rules for determining dependency, such as including all items associated with a particular passage, may overestimate the dependency…
Negations in syllogistic reasoning: evidence for a heuristic-analytic conflict.
Stupple, Edward J N; Waterhouse, Eleanor F
2009-08-01
An experiment utilizing response time measures was conducted to test dominant processing strategies in syllogistic reasoning with the expanded quantifier set proposed by Roberts (2005). Through adding negations to existing quantifiers it is possible to change problem surface features without altering logical validity. Biases based on surface features such as atmosphere, matching, and the probability heuristics model (PHM; Chater & Oaksford, 1999; Wetherick & Gilhooly, 1995) would not be expected to show variance in response latencies, but participant responses should be highly sensitive to changes in the surface features of the quantifiers. In contrast, according to analytic accounts such as mental models theory and mental logic (e.g., Johnson-Laird & Byrne, 1991; Rips, 1994) participants should exhibit increased response times for negated premises, but not be overly impacted upon by the surface features of the conclusion. Data indicated that the dominant response strategy was based on a matching heuristic, but also provided evidence of a resource-demanding analytic procedure for dealing with double negatives. The authors propose that dual-process theories offer a stronger account of these data whereby participants employ competing heuristic and analytic strategies and fall back on a heuristic response when analytic processing fails.
On Some Stopping Times of Citation Processes. From Theory to Indicators.
ERIC Educational Resources Information Center
Glanzel, Wolfgang
1992-01-01
Proposes a new measure of the citation speed of scientific publications based on a stopping time approach. The stochastic process approach in bibliometrics is described, mean response time (MRT) is discussed, harmonic mean response time (HMRT) is explained, and examples are given. (six references) (LRW)
Power and Responsibility in Therapy: Integrating Feminism and Multiculturalism
ERIC Educational Resources Information Center
Williams, Elizabeth Nutt; Barber, Jill S.
2004-01-01
The integration of feminist and multicultural approaches to psychotherapy, called for many times, has not yet materialized. This article reviews possible reasons this integration has not taken place and offers an approach to integration based on the guiding principles of power and responsibility, which builds on previous theories and approaches.
Model Selection Indices for Polytomous Items
ERIC Educational Resources Information Center
Kang, Taehoon; Cohen, Allan S.; Sung, Hyun-Jung
2009-01-01
This study examines the utility of four indices for use in model selection with nested and nonnested polytomous item response theory (IRT) models: a cross-validation index and three information-based indices. Four commonly used polytomous IRT models are considered: the graded response model, the generalized partial credit model, the partial credit…
Log-Multiplicative Association Models as Item Response Models
ERIC Educational Resources Information Center
Anderson, Carolyn J.; Yu, Hsiu-Ting
2007-01-01
Log-multiplicative association (LMA) models, which are special cases of log-linear models, have interpretations in terms of latent continuous variables. Two theoretical derivations of LMA models based on item response theory (IRT) arguments are presented. First, we show that Anderson and colleagues (Anderson & Vermunt, 2000; Anderson & Bockenholt,…
Parent Social Networks and Parent Responsibility: Implications for School Leadership
ERIC Educational Resources Information Center
Curry, Katherine A.; Adams, Curt M.
2014-01-01
Family-school partnerships are difficult to initiate and sustain in ways that actually promote student learning, especially in high-poverty communities. This quantitative study was designed to better understand how social forces shape parent responsibility in education. Based on social cognitive theory as the conceptual framework, the…
Item Response Theory for Peer Assessment
ERIC Educational Resources Information Center
Uto, Masaki; Ueno, Maomi
2016-01-01
As an assessment method based on a constructivist approach, peer assessment has become popular in recent years. However, in peer assessment, a problem remains that reliability depends on the rater characteristics. For this reason, some item response models that incorporate rater parameters have been proposed. Those models are expected to improve…
Applying Generalizability Theory for Making Quantitative RTI Progress-Monitoring Decisions
ERIC Educational Resources Information Center
Fan, Chung-Hau; Hansmann, Paul R.
2015-01-01
Language in the Individuals With Disabilities Education Improvement Act (IDEIA) allows the use of response-to-intervention (RTI) methodology in the identification of specific learning disabilities. However, there is no consensus on decision rules using curriculum-based measurement of oral reading fluency (CBM-R) for defining responsiveness. The…
Application of an IRT Polytomous Model for Measuring Health Related Quality of Life
ERIC Educational Resources Information Center
Tejada, Antonio J. Rojas; Rojas, Oscar M. Lozano
2005-01-01
Background: The Item Response Theory (IRT) has advantages for measuring Health Related Quality of Life (HRQOL) as opposed to the Classical Tests Theory (CTT). Objectives: To present the results of the application of a polytomous model based on IRT, specifically, the Rating Scale Model (RSM), to measure HRQOL with the EORTC QLQ-C30. Methods: 103…
A Test of Cognitive Dissonance Theory to Explain Parents' Reactions to Youths' Alcohol Intoxication
ERIC Educational Resources Information Center
Glatz, Terese; Stattin, Hakan; Kerr, Margaret
2012-01-01
Studies have shown that parents reduce control and support in response to youths' drinking. Why they react this way, however, is still unknown. From cognitive dissonance theory, we derived hypotheses about parents' reactions. We used a longitudinal, school-based sample of 494 youths (13 and 14 years, 56% boys) and their parents. General Linear…
ERIC Educational Resources Information Center
O'Nions, Elizabeth; Sebastian, Catherine L.; McCrory, Eamon; Chantiluke, Kaylita; Happé, Francesca; Viding, Essi
2014-01-01
Individuals with autism spectrum disorders (ASD) have difficulty understanding other minds (Theory of Mind; ToM), with atypical processing evident at both behavioural and neural levels. Individuals with conduct problems and high levels of callous-unemotional (CU) traits (CP/HCU) exhibit reduced responsiveness to others' emotions and difficulties…
ERIC Educational Resources Information Center
Çokluk, Ömay; Gül, Emrah; Dogan-Gül, Çilem
2016-01-01
The study aims to examine whether differential item function is displayed in three different test forms that have item orders of random and sequential versions (easy-to-hard and hard-to-easy), based on Classical Test Theory (CTT) and Item Response Theory (IRT) methods and bearing item difficulty levels in mind. In the correlational research, the…
Expertise facilitates the transfer of anticipation skill across domains.
Rosalie, Simon M; Müller, Sean
2014-02-01
It is unclear whether perceptual-motor skill transfer is based upon similarity between the learning and transfer domains per identical elements theory, or facilitated by an understanding of underlying principles in accordance with general principle theory. Here, the predictions of identical elements theory, general principle theory, and aspects of a recently proposed model for the transfer of perceptual-motor skill with respect to expertise in the learning and transfer domains are examined. The capabilities of expert karate athletes, near-expert karate athletes, and novices to anticipate and respond to stimulus skills derived from taekwondo and Australian football were investigated in ecologically valid contexts using an in situ temporal occlusion paradigm and complex whole-body perceptual-motor skills. Results indicated that the karate experts and near-experts are as capable of using visual information to anticipate and guide motor skill responses as domain experts and near-experts in the taekwondo transfer domain, but only karate experts could perform like domain experts in the Australian football transfer domain. Findings suggest that transfer of anticipation skill is based upon expertise and an understanding of principles but may be supplemented by similarities that exist between the stimulus and response elements of the learning and transfer domains.
NASA Astrophysics Data System (ADS)
Zhang, Min; He, Weiyi
2018-06-01
Under the guidance of principal-agent theory and modular theory, the collaborative innovation of green technology-based companies, design contractors and project builders based on united agency will provide direction for the development of green construction supply chain in the future. After analyzing the existing independent agencies, this paper proposes the industry-university-research bilateral collaborative innovation network architecture and modularization with the innovative function of engineering design in the context of non-standard transformation interfaces, analyzes the innovation responsibility center, and gives some countermeasures and suggestions to promote the performance of bilateral cooperative innovation network.
Hartogsohn, Ido
2016-12-01
Placebo response theory and set and setting theory are two fields which examine how non-biological factors shape the response to therapy. Both consider factors such as expectancy, preparation and beliefs to be crucial for understanding the extra-pharmacological processes which shape the response to drugs. Yet there are also fundamental differences between the two theories. Set and setting concerns itself with response to psychoactive drugs only; placebo theory relates to all therapeutic interventions. Placebo theory is aimed at medical professionals; set and setting theory is aimed at professionals and drug users alike. Placebo theory is primarily descriptive, describing how placebo acts; set and setting theory is primarily prescriptive, educating therapists and users on how to control and optimize the effects of drugs. This paper examines how placebo theory and set and setting theory can complement and benefit each other, broadening our understanding of how non-biological factors shape response to drugs and other treatment interventions. © The Author(s) 2016.
Exploring the relation between people’s theories of intelligence and beliefs about brain development
Thomas, Ashley J.; Sarnecka, Barbara W.
2015-01-01
A person’s belief about whether intelligence can change (called their implicit theory of intelligence) predicts something about that person’s thinking and behavior. People who believe intelligence is fixed (called entity theorists) attribute failure to traits (i.e., “I failed the test because I’m not smart.”) and tend to be less motivated in school; those who believe intelligence is malleable (called incremental theorists) tend to attribute failure to behavior (i.e., “I failed the test because I didn’t study.”) and are more motivated in school. In previous studies, researchers have characterized participants as either entity or incremental theorists based on their agreement or disagreement with three statements. The present study further explored the theories-of-intelligence (TOI) construct in two ways: first, we asked whether these theories are coherent, in the sense that they show up not only in participants’ responses to the three standard assessment items, but on a broad range of questions about intelligence and the brain. Second, we asked whether these theories are discrete or continuous. In other words, we asked whether people believe one thing or the other (i.e., that intelligence is malleable or fixed), or if there is a continuous range of beliefs (i.e., people believe in malleability to a greater or lesser degree). Study (1) asked participants a range of general questions about the malleability of intelligence and the brain. Study (2) asked participants more specific questions about the brains of a pair of identical twins who were separated at birth. Results showed that TOI are coherent: participants’ responses to the three standard survey items are correlated with their responses to questions about the brain. But the theories are not discrete: although responses to the three standard survey items fell into a bimodal distribution, responses to the broader range of questions fell into a normal distribution suggesting the theories are continuous. PMID:26191027
NASA Astrophysics Data System (ADS)
Camporesi, Roberto
2011-06-01
We present an approach to the impulsive response method for solving linear constant-coefficient ordinary differential equations based on the factorization of the differential operator. The approach is elementary, we only assume a basic knowledge of calculus and linear algebra. In particular, we avoid the use of distribution theory, as well as of the other more advanced approaches: Laplace transform, linear systems, the general theory of linear equations with variable coefficients and the variation of constants method. The approach presented here can be used in a first course on differential equations for science and engineering majors.
Ralph, Jason; Gifkins, Jess
2017-09-01
Practice theory provides important insights into the workings of the Security Council. The contribution is currently limited, however, by the conjecture that practice theory operates on 'a different analytical plane' to norm/normative theory. Building on existing critiques, we argue that analysing practices separately from normative positions risks misappropriating competence and reifying practice that is not fit for purpose. This risk is realized in Adler-Nissen and Pouliot's practice-based account of the Libya crisis. By returning the normative context created by the Responsibility to Protect to the analytical foreground, and by drawing on a pragmatic conception of 'ethical competence', we find that pre-reflexive practices uncritically accepted as markers of competence - for example, 'penholding' - can contribute to the Council's failure to act collectively in the face of mass atrocity. Drawing on extensive interview material, we offer an alternative account of the Libya intervention, finding that the practices of the permanent three (France, the UK and the US) did not cultivate the kind of collective consciousness that is required to implement the Responsibility to Protect. This is further illustrated by an account of the Security Council's failure in Syria, where the permanent three's insistence on regime change instrumentalized the Council at the expense of Responsibility to Protect-appropriate practice. This changed when elected members became 'penholders'. Practice theory can facilitate learning processes that help the Council meet its responsibilities, but only through an approach that combines its insights with those of norm/normative theory.
Ralph, Jason; Gifkins, Jess
2016-01-01
Practice theory provides important insights into the workings of the Security Council. The contribution is currently limited, however, by the conjecture that practice theory operates on ‘a different analytical plane’ to norm/normative theory. Building on existing critiques, we argue that analysing practices separately from normative positions risks misappropriating competence and reifying practice that is not fit for purpose. This risk is realized in Adler-Nissen and Pouliot’s practice-based account of the Libya crisis. By returning the normative context created by the Responsibility to Protect to the analytical foreground, and by drawing on a pragmatic conception of ‘ethical competence’, we find that pre-reflexive practices uncritically accepted as markers of competence — for example, ‘penholding’ — can contribute to the Council’s failure to act collectively in the face of mass atrocity. Drawing on extensive interview material, we offer an alternative account of the Libya intervention, finding that the practices of the permanent three (France, the UK and the US) did not cultivate the kind of collective consciousness that is required to implement the Responsibility to Protect. This is further illustrated by an account of the Security Council’s failure in Syria, where the permanent three’s insistence on regime change instrumentalized the Council at the expense of Responsibility to Protect-appropriate practice. This changed when elected members became ‘penholders’. Practice theory can facilitate learning processes that help the Council meet its responsibilities, but only through an approach that combines its insights with those of norm/normative theory. PMID:29278256
NASA Astrophysics Data System (ADS)
Chen, Chung-De
2018-04-01
In this paper, a distributed parameter electromechanical model for bimorph piezoelectric energy harvesters based on the refined zigzag theory (RZT) is developed. In this model, the zigzag function is incorporated into the axial displacement, and the zigzag distribution of the displacement between the adjacent layers of the bimorph structure can be considered. The governing equations, including three equations of motions and one equation of circuit, are derived using Hamilton’s principle. The natural frequency, its corresponding modal function and the steady state response of the base excitation motion are given in exact forms. The presented results are benchmarked with the finite element method and two beam theories, the first-order shear deformation theory and the classical beam theory. Comparing examples shows that the RZT provides predictions of output voltage and generated power at high accuracy, especially for the case of a soft middle layer. Variation of the parameters, such as the beam thickness, excitation frequencies and the external electrical loads, is investigated and its effects on the performance of the energy harvesters are studied by using the RZT developed in this paper. Based on this refined theory, analysts and engineers can capture more details on the electromechanical behavior of piezoelectric harvesters.
Stice, Eric; Yokum, Sonja; Waters, Allison
2015-01-01
Research supports the effectiveness of a dissonance-based eating disorder prevention program wherein high-risk young women with body dissatisfaction critique the thin ideal, which reduces pursuit of this ideal, and the theory that dissonance induction contributes to these effects. Based on evidence that dissonance produces attitudinal change by altering neural representation of valuation, we tested whether completing the Body Project would reduce response of brain regions implicated in reward valuation to thin models. Young women with body dissatisfaction were randomized to this intervention or an educational control condition, completing assessments and fMRI scans while viewing images of thin versus average-weight female models at pre and post. Whole brain analyses indicated that, compared to controls, Body Project participants showed greater reductions in caudate response to images of thin versus average-weight models, though participants in the two conditions showed pretest differences in responsivity of other brain regions that might have contributed to this effect. Greater pre-post reductions in caudate and putamen response to thin models correlated with greater reductions in body dissatisfaction. The finding that the Body Project reduces caudate response to thin models provides novel preliminary evidence that this intervention reduces valuation of media images thought to contribute to body dissatisfaction and eating disorders, providing support for the intervention theory by documenting that this intervention alters an objective biological outcome. PMID:26641854
Stice, Eric; Yokum, Sonja; Waters, Allison
2015-01-01
Research supports the effectiveness of a dissonance-based eating disorder prevention program wherein high-risk young women with body dissatisfaction critique the thin ideal, which reduces pursuit of this ideal, and the theory that dissonance induction contributes to these effects. Based on evidence that dissonance produces attitudinal change by altering neural representation of valuation, we tested whether completing the Body Project would reduce response of brain regions implicated in reward valuation to thin models. Young women with body dissatisfaction were randomized to this intervention or an educational control condition, completing assessments and fMRI scans while viewing images of thin versus average-weight female models at pre and post. Whole brain analyses indicated that, compared to controls, Body Project participants showed greater reductions in caudate response to images of thin versus average-weight models, though participants in the two conditions showed pretest differences in responsivity of other brain regions that might have contributed to this effect. Greater pre-post reductions in caudate and putamen response to thin models correlated with greater reductions in body dissatisfaction. The finding that the Body Project reduces caudate response to thin models provides novel preliminary evidence that this intervention reduces valuation of media images thought to contribute to body dissatisfaction and eating disorders, providing support for the intervention theory by documenting that this intervention alters an objective biological outcome.
Ravichandran, M; Kulanthaivel, G; Chellatamilan, T
2015-01-01
Every day, huge numbers of instant tweets (messages) are published on Twitter as it is one of the massive social media for e-learners interactions. The options regarding various interesting topics to be studied are discussed among the learners and teachers through the capture of ideal sources in Twitter. The common sentiment behavior towards these topics is received through the massive number of instant messages about them. In this paper, rather than using the opinion polarity of each message relevant to the topic, authors focus on sentence level opinion classification upon using the unsupervised algorithm named bigram item response theory (BIRT). It differs from the traditional classification and document level classification algorithm. The investigation illustrated in this paper is of threefold which are listed as follows: (1) lexicon based sentiment polarity of tweet messages; (2) the bigram cooccurrence relationship using naïve Bayesian; (3) the bigram item response theory (BIRT) on various topics. It has been proposed that a model using item response theory is constructed for topical classification inference. The performance has been improved remarkably using this bigram item response theory when compared with other supervised algorithms. The experiment has been conducted on a real life dataset containing different set of tweets and topics.
The e-MSWS-12: improving the multiple sclerosis walking scale using item response theory.
Engelhard, Matthew M; Schmidt, Karen M; Engel, Casey E; Brenton, J Nicholas; Patek, Stephen D; Goldman, Myla D
2016-12-01
The Multiple Sclerosis Walking Scale (MSWS-12) is the predominant patient-reported measure of multiple sclerosis (MS) -elated walking ability, yet it had not been analyzed using item response theory (IRT), the emerging standard for patient-reported outcome (PRO) validation. This study aims to reduce MSWS-12 measurement error and facilitate computerized adaptive testing by creating an IRT model of the MSWS-12 and distributing it online. MSWS-12 responses from 284 subjects with MS were collected by mail and used to fit and compare several IRT models. Following model selection and assessment, subpopulations based on age and sex were tested for differential item functioning (DIF). Model comparison favored a one-dimensional graded response model (GRM). This model met fit criteria and explained 87 % of response variance. The performance of each MSWS-12 item was characterized using category response curves (CRCs) and item information. IRT-based MSWS-12 scores correlated with traditional MSWS-12 scores (r = 0.99) and timed 25-foot walk (T25FW) speed (r = -0.70). Item 2 showed DIF based on age (χ 2 = 19.02, df = 5, p < 0.01), and Item 11 showed DIF based on sex (χ 2 = 13.76, df = 5, p = 0.02). MSWS-12 measurement error depends on walking ability, but could be lowered by improving or replacing items with low information or DIF. The e-MSWS-12 includes IRT-based scoring, error checking, and an estimated T25FW derived from MSWS-12 responses. It is available at https://ms-irt.shinyapps.io/e-MSWS-12 .
Papagiannakis, Giorgos; Lioukas, Spyros
2012-06-15
We examine whether managers' values, attitudes, and perceptions influence the greening of organizations. To that purpose, we specify and test a model of corporate environmental responsiveness (CER), drawing upon a modified version of the theory of planned behavior and the value-belief-norm theory. Based on survey data from 142 Greek companies, we find that top managers' personal values influence responses indirectly, through shaping their environmental attitudes, while direct relationship is not significant. Subjective norms, expressing stakeholder expectations, do affect CER, with their effect being stronger than that of attitudes. Managers' perceived ability to handle environmental issues also appears to influence responses. Results have theoretical implications, indicating the significant role of managers' values, attitudes and perceptions in a firm's environmental response. Practical implications are discussed in relation to selection of managers and training. Copyright © 2012 Elsevier Ltd. All rights reserved.
Gust response of commercial jet aircraft including effects of autopilot operation
NASA Technical Reports Server (NTRS)
Goldberg, J. H.
1982-01-01
A simplified theory of aircraft vertical acceleration gust response based on a model including pitch, vertical displacement and control motions due to autopilot operation is presented. High-order autopilot transfer functions are utilized for improved accuracy in the determination of the overall response characteristics. Four representative commercial jet aircraft were studied over a wide range of operating conditions and comparisons of individual responses are given. It is shown that autopilot operation relative to the controls fixed case causes response attenuation of from 10 percent to approximately 25 percent depending on flight condition and increases in crossing number up to 30 percent, with variations between aircraft of from 5 percent to 10 percent, in general, reflecting the differences in autopilot design. A detailed computer program description and listing of the calculation procedure suitable for the general application of the theory to any airplane autopilot combination is also included.
Exact solutions for laminated composite cylindrical shells in cylindrical bending
NASA Technical Reports Server (NTRS)
Yuan, F. G.
1992-01-01
Analytic elasticity solutions for laminated composite cylindrical shells under cylindrical bending are presented. The material of the shell is assumed to be general cylindrically anisotropic. Based on the theory of cylindrical anisotropic elasticity, coupled governing partial differential equations are developed. The general expressions for the stresses and displacements in the laminated composite cylinders are discussed. The closed form solutions based on Classical Shell Theory (CST) and Donnell's (1933) theory are also derived for comparison purposes. Three examples illustrate the effect of radius-to-thickness ratio, coupling and stacking sequence. The results show that, in general, CST yields poor stress and displacement distributions for thick-section composite shells, but converges to the exact elasticity solution as the radius-to-thickness ratio increases. It is also shown that Donnell's theory significantly underestimates the stress and displacement response.
Khorramdel, Lale; von Davier, Matthias
2014-01-01
This study shows how to address the problem of trait-unrelated response styles (RS) in rating scales using multidimensional item response theory. The aim is to test and correct data for RS in order to provide fair assessments of personality. Expanding on an approach presented by Böckenholt (2012), observed rating data are decomposed into multiple response processes based on a multinomial processing tree. The data come from a questionnaire consisting of 50 items of the International Personality Item Pool measuring the Big Five dimensions administered to 2,026 U.S. students with a 5-point rating scale. It is shown that this approach can be used to test if RS exist in the data and that RS can be differentiated from trait-related responses. Although the extreme RS appear to be unidimensional after exclusion of only 1 item, a unidimensional measure for the midpoint RS is obtained only after exclusion of 10 items. Both RS measurements show high cross-scale correlations and item response theory-based (marginal) reliabilities. Cultural differences could be found in giving extreme responses. Moreover, it is shown how to score rating data to correct for RS after being proved to exist in the data.
Dehdari, Tahereh; Hassani, Laleh; Hajizadeh, Ebrahim; Shojaeizadeh, Davoud; Nedjat, Saharnaz; Abedini, Mehrandokht
2014-01-01
Few Iranian women take the Papanicolaou test despite its important role in preventing cervical cancer. This study aimed to determine the effectiveness of an educational intervention based on the protection motivation theory (PMT) variables and implementation intentions in the first and second Pap test practice among Iranian women. In this quasi-randomized controlled trial, 200 women who were referred to 30 primary health care clinics in Tehran were randomly selected. PMT variables and Pap test practice were measured at baseline and again after 3 and 15 months. The 4-week educational intervention program was conducted for the intervention group. Following the intervention, the mean scores of self-efficacy, perceived vulnerability, and behavior intention variables were significantly higher in the intervention group when compared to the control group (p<0.05). No significant differences were found in the perceived severity, response efficacy, response cost, and fear between the two groups following the intervention. Higher percent of women in the intervention group had obtained first and second Pap test compared to the controls. The PMT and implementation intentions provide a suitable theory-based framework for developing educational interventions regarding Pap test practice in Iran.
Theoretical Modeling and Electromagnetic Response of Complex Metamaterials
2017-03-06
AFRL-AFOSR-VA-TR-2017-0042 Theoretical Modeling and Electromagnetic Response of Complex Metamaterials Andrea Alu UNIVERSITY OF TEXAS AT AUSTIN Final...Nov 2016 4. TITLE AND SUBTITLE Theoretical Modeling and Electromagnetic Response of Complex Metamaterials 5a. CONTRACT NUMBER 5b. GRANT NUMBER...based on parity-time symmetric metasurfaces, and various advances in electromagnetic and acoustic theory and applications. Our findings have opened
NASA Astrophysics Data System (ADS)
Pérez-Moreno, Javier; Clays, Koen; Kuzyk, Mark G.
2010-05-01
We present a procedure for the modeling of the dispersion of the nonlinear optical response of complex molecular structures that is based strictly on the results from experimental characterization. We show how under some general conditions, the use of the Thomas-Kuhn sum-rules leads to a successful modeling of the nonlinear response of complex molecular structures.
Item Response Modeling with Sum Scores
ERIC Educational Resources Information Center
Johnson, Timothy R.
2013-01-01
One of the distinctions between classical test theory and item response theory is that the former focuses on sum scores and their relationship to true scores, whereas the latter concerns item responses and their relationship to latent scores. Although item response theory is often viewed as the richer of the two theories, sum scores are still…
NASA Astrophysics Data System (ADS)
Luscher, Darby
2017-06-01
The dynamic thermomechanical responses of polycrystalline materials under shock loading are often dominated by the interaction of defects and interfaces. For example, polymer-bonded explosives (PBX) can initiate under weak shock impacts whose energy, if distributed homogeneously throughout the material, translates to temperature increases that are insufficient to drive the rapid chemistry observed. In such cases, heterogeneous thermomechanical interactions at the mesoscale (i.e. between single-crystal and macroscale) lead to the formation of localized hot spots. Within metals, a prescribed deformation associated with a shock wave may be accommodated by crystallographic slip, provided a sufficient population of mobile dislocations is available. However, if the deformation rate is large enough, there may be an insufficient number of freely mobile dislocations. In these cases, additional dislocations may be nucleated, or alternate mechanisms (e.g. twinning, damage) activated in order to accommodate the deformation. Direct numerical simulation at the mesoscale offers insight into these physical processes that can be invaluable to the development of macroscale constitutive theories, if the mesoscale models adequately represent the anisotropic nonlinear thermomechanical response of individual crystals and their interfaces. This talk will briefly outline a continuum mesoscale modeling framework founded upon local and nonlocal variations of dislocation-density based crystal plasticity theory. The nonlocal theory couples continuum dislocation transport with the local theory. In the latter, dislocation transport is modeled by enforcing dislocation conservation at a slip-system level through the solution of advection-diffusion equations. The configuration of geometrically necessary dislocation density gives rise to a back-stress that inhibits or accentuates the flow of dislocations. Development of the local theory and application to modeling the explosive molecular crystal RDX and polycrystalline PBX will be discussed. The talk will also emphasize recent implementation of the coupled nonlocal model into a 3D shock hydrocode and simulation results for the dynamic response of polycrystalline copper in two and three dimensions.
NASA Astrophysics Data System (ADS)
Stillwater, Tai
A large body of evidence suggests that drivers who receive real-time fuel economy information can increase their vehicle fuel economy by 5%, a process commonly known as ecodriving. However, few studies have directly addressed the human side of the feedback, that is, why drivers would (or would not) be motivated to change their behavior and how to design feedback devices to maximize the motivation to ecodrive. This dissertation approaches the question using a mixed qualitative and quantitative approach to explore driver responses and psychology as well as to quantify the process of behavior change. The first chapter discusses the use of mile-per-gallon fuel economy as a metric for driver feedback and finds that an alternative energy economy metric is superior for real-time feedback. The second chapter reviews behavioral theories and proposes a number of practical solutions for the ecodriving context. In the third chapter the theory of planned behavior is tested against driver responses to an existing feedback system available in the 2008 model Toyota Prius. The fourth chapter presents a novel feedback design based on behavioral theories and drivers' responses to the feedback. Finally, chapter five presents the quantitative results of a natural-driving study of fuel economy feedback. The dissertation findings suggest that behavior theories such as the Theory of Planned Behavior can provide important improvements to existing feedback designs. In addition, a careful analysis of vehicle energy flows indicates that the mile-per-gallon metric is deeply flawed as a real-time feedback metric, and should be replaced. Chapters 2 and 3 conclude that behavior theories have both a theoretical and highly practical role in feedback design, although the driving context requires just as much care in the application. Chapters 4 and 5 find that a theory-inspired interface provides drivers with engaging and motivating feedback, and that integrating personal goal into the feedback is the most motivating theory-based addition. Finally, the behavioral model results in chapter 5 suggest that driver goals not only influence in-vehicle energy use, but are themselves flexible constructs that can be directly influenced by energy feedback.
ERIC Educational Resources Information Center
Suchman, Sara P.
2012-01-01
The No Child Left Behind Act of 2001 mandated that states implement standards and test-based accountability systems. In theory, local educators are free to select the means for teaching the standards so long as students achieve a predetermined proficiency level on the exams. What is unclear, however, is how this theory plays out in schools…
The Robustness of IRT-Based Vertical Scaling Methods to Violation of Unidimensionality
ERIC Educational Resources Information Center
Yin, Liqun
2013-01-01
In recent years, many states have adopted Item Response Theory (IRT) based vertically scaled tests due to their compelling features in a growth-based accountability context. However, selection of a practical and effective calibration/scaling method and proper understanding of issues with possible multidimensionality in the test data is critical to…
Ghahremani, Leila; Faryabi, Reza; Kaveh, Mohammad Hossein
2014-01-01
Background: Malaria is one of the most serious diseases in pregnant women as well as children less than 5 years around the world. The present study aimed to investigate the effect of health education based on the protection motivation theory on malaria preventive behaviors in the households of Ghale Ganj, Kerman, Iran in 2011. Methods: The present quasi-experimental study was conducted on 144 households covered by 8 health centers of Ghale Ganj, Kerman. The study samples were selected through systematic random sampling and the study data were collected using a questionnaire including demographic information, the constructs of the protection motivation theory, and a checklist for assessing the malaria preventive behaviors. After the pre-test, the intervention group underwent an educational intervention and after two months, the post-test was performed through the same questionnaire. Then, the data were entered into the SPSS statistical software (v. 18) and analyzed using Chi-square and Wilcoxon non-parametric tests. Besides, P < 0.05 was considered as statistically significant. Results: Before the intervention, no significant difference was found between the two study groups regarding perceived vulnerability, perceived severity, response costs, self-efficacy, response efficacy, and malaria preventive behaviors. After the intervention, however, a significant increase was observed in the intervention group's mean scores of all the constructs of the protection motivation theory as well as malaria preventive behaviors (P < 0.01). Conclusions: According to the findings of the study, educational intervention based on the protection motivation theory is highly effective in promoting malaria preventive behaviors. PMID:24829734
Ghahremani, Leila; Faryabi, Reza; Kaveh, Mohammad Hossein
2014-04-01
Malaria is one of the most serious diseases in pregnant women as well as children less than 5 years around the world. The present study aimed to investigate the effect of health education based on the protection motivation theory on malaria preventive behaviors in the households of Ghale Ganj, Kerman, Iran in 2011. The present quasi-experimental study was conducted on 144 households covered by 8 health centers of Ghale Ganj, Kerman. The study samples were selected through systematic random sampling and the study data were collected using a questionnaire including demographic information, the constructs of the protection motivation theory, and a checklist for assessing the malaria preventive behaviors. After the pre-test, the intervention group underwent an educational intervention and after two months, the post-test was performed through the same questionnaire. Then, the data were entered into the SPSS statistical software (v. 18) and analyzed using Chi-square and Wilcoxon non-parametric tests. Besides, P < 0.05 was considered as statistically significant. Before the intervention, no significant difference was found between the two study groups regarding perceived vulnerability, perceived severity, response costs, self-efficacy, response efficacy, and malaria preventive behaviors. After the intervention, however, a significant increase was observed in the intervention group's mean scores of all the constructs of the protection motivation theory as well as malaria preventive behaviors (P < 0.01). According to the findings of the study, educational intervention based on the protection motivation theory is highly effective in promoting malaria preventive behaviors.
An Evaluation of Three Approximate Item Response Theory Models for Equating Test Scores.
ERIC Educational Resources Information Center
Marco, Gary L.; And Others
Three item response models were evaluated for estimating item parameters and equating test scores. The models, which approximated the traditional three-parameter model, included: (1) the Rasch one-parameter model, operationalized in the BICAL computer program; (2) an approximate three-parameter logistic model based on coarse group data divided…
NASA Technical Reports Server (NTRS)
Chu, Y. Y.
1978-01-01
A unified formulation of computer-aided, multi-task, decision making is presented. Strategy for the allocation of decision making responsibility between human and computer is developed. The plans of a flight management systems are studied. A model based on the queueing theory was implemented.
Moral Development: Making the Connection between Choices, Responsibility and Self-Esteem.
ERIC Educational Resources Information Center
Walsh, Julia A.
This paper discusses strategies and techniques that early childhood educators can use to encourage self-esteem and responsibility in young children. It examines Kohlberg's theory of moral values, which states that children progress through three stages of moral development: (1) the pre-moral stage, based on rewards and punishments; (2) the moral…
The Limits of Dialogue among Teachers from Different National Contexts
ERIC Educational Resources Information Center
Shim, Jenna Min
2015-01-01
In this study, the author investigates the dynamics of dialogue among teachers in different national contexts based on their responses to different cultural practices. Employing Pierre Bourdieu's sociological theory of practice and his concept of habitus, the author shows that, as the teachers' responses are not entirely context-specific, they are…
Developing Culturally Responsive Youth Workers
ERIC Educational Resources Information Center
Walter, Ann; Grant, Samantha
2011-01-01
Culturally Responsive Youth Work: The Journey Matters is based on the theory that when knowledge and skills are found within the lived experiences and cultural contexts of youth, they are more meaningful and more engaging and are learned more easily (Gay, 2000). The program was evaluated using a retrospective pre-then-post test evaluation and…
Preservice Teachers Experience Reading Response Pedagogy in a Multi-User Virtual Environment
ERIC Educational Resources Information Center
Dooley, Caitlin McMunn; Calandra, Brendan; Harmon, Stephen
2014-01-01
This qualitative case study describes how 18 preservice teachers learned to nurture literary meaning-making via activities based on Louise Rosenblatt's Reader Response Theory within a multi-user virtual environment (MUVE). Participants re-created and responded to scenes from selected works of children's literature in Second Life as a way to…
Distinct Roles of Dopamine and Subthalamic Nucleus in Learning and Probabilistic Decision Making
ERIC Educational Resources Information Center
Coulthard, Elizabeth J.; Bogacz, Rafal; Javed, Shazia; Mooney, Lucy K.; Murphy, Gillian; Keeley, Sophie; Whone, Alan L.
2012-01-01
Even simple behaviour requires us to make decisions based on combining multiple pieces of learned and new information. Making such decisions requires both learning the optimal response to each given stimulus as well as combining probabilistic information from multiple stimuli before selecting a response. Computational theories of decision making…
ERIC Educational Resources Information Center
Qian, Hong; Youngs, Peter; Frank, Kenneth
2013-01-01
This paper uses theory from sociology of education to explore associations between mentors' and senior colleagues' perceptions of schoolwide collective responsibility and the frequency of their interactions with novice teachers. Survey data was collected from novice teachers, their mentors, and their school-based colleagues in 6 Michigan districts…
Modeling noisy resonant system response
NASA Astrophysics Data System (ADS)
Weber, Patrick Thomas; Walrath, David Edwin
2017-02-01
In this paper, a theory-based model replicating empirical acoustic resonant signals is presented and studied to understand sources of noise present in acoustic signals. Statistical properties of empirical signals are quantified and a noise amplitude parameter, which models frequency and amplitude-based noise, is created, defined, and presented. This theory-driven model isolates each phenomenon and allows for parameters to be independently studied. Using seven independent degrees of freedom, this model will accurately reproduce qualitative and quantitative properties measured from laboratory data. Results are presented and demonstrate success in replicating qualitative and quantitative properties of experimental data.
Molecular polarizability of water from local dielectric response theory
Ge, Xiaochuan; Lu, Deyu
2017-08-08
Here, we propose a fully ab initio theory to compute the electron density response under the perturbation in the local field. This method is based on our recently developed local dielectric response theory [Phys. Rev. B 92, 241107(R), 2015], which provides a rigorous theoretical framework to treat local electronic excitations in both nite and extended systems beyond the commonly employed dipole approximation. We have applied this method to study the electronic part of the molecular polarizability of water in ice Ih and liquid water. Our results reveal that the crystal field of the hydrogen-bond network has strong anisotropic effects, whichmore » significantly enhance the out-of-plane component and suppress the in-plane component perpendicular to the bisector direction. The contribution from the charge transfer is equally important, which increases the isotropic molecular polarizability by 5-6%. Our study provides new insights into the dielectric properties of water, which form the basis to understand electronic excitations in water and to develop accurate polarizable force fields of water.« less
Kelly, Ursula A
2011-01-01
Intimate partner violence (IPV) has garnered increasing public and academic attention in the past several decades. Theories about the causes, prevention, and intervention for IPV have developed in complexity. This article provides an overview of the historical roots of IPV, as well as a description and critique of historical and contemporary theories of IPV causes and women's responses to IPV. This is followed by a discussion of the most current theoretical developments and application of critical theories to the problem of IPV. The article concludes with theoretically based implications for nursing practice and research with women who are experiencing IPV.
NASA Astrophysics Data System (ADS)
Ansari, R.; Sahmani, S.
2012-04-01
The free vibration response of single-walled carbon nanotubes (SWCNTs) is investigated in this work using various nonlocal beam theories. To this end, the nonlocal elasticity equations of Eringen are incorporated into the various classical beam theories namely as Euler-Bernoulli beam theory (EBT), Timoshenko beam theory (TBT), and Reddy beam theory (RBT) to consider the size-effects on the vibration analysis of SWCNTs. The generalized differential quadrature (GDQ) method is employed to discretize the governing differential equations of each nonlocal beam theory corresponding to four commonly used boundary conditions. Then molecular dynamics (MD) simulation is implemented to obtain fundamental frequencies of nanotubes with different chiralities and values of aspect ratio to compare them with the results obtained by the nonlocal beam models. Through the fitting of the two series of numerical results, appropriate values of nonlocal parameter are derived relevant to each type of chirality, nonlocal beam model, and boundary conditions. It is found that in contrast to the chirality, the type of nonlocal beam model and boundary conditions make difference between the calibrated values of nonlocal parameter corresponding to each one.
Microscopic theory of linear light scattering from mesoscopic media and in near-field optics.
Keller, Ole
2005-08-01
On the basis of quantum mechanical response theory a microscopic propagator theory of linear light scattering from mesoscopic systems is presented. The central integral equation problem is transferred to a matrix equation problem by discretization in transitions between pairs of (many-body) energy eigenstates. The local-field calculation which appears from this approach is valid down to the microscopic region. Previous theories based on the (macroscopic) dielectric constant concept make use of spatial (geometrical) discretization and cannot in general be trusted on the mesoscopic length scale. The present theory can be applied to light scattering studies in near-field optics. After a brief discussion of the macroscopic integral equation problem a microscopic potential description of the scattering process is established. In combination with the use of microscopic electromagnetic propagators the formalism allows one to make contact to the macroscopic theory of light scattering and to the spatial photon localization problem. The quantum structure of the microscopic conductivity response tensor enables one to establish a clear physical picture of the origin of local-field phenomena in mesoscopic and near-field optics. The Huygens scalar propagator formalism is revisited and its generality in microscopic physics pointed out.
MaxEnt-Based Ecological Theory: A Template for Integrated Catchment Theory
NASA Astrophysics Data System (ADS)
Harte, J.
2017-12-01
The maximum information entropy procedure (MaxEnt) is both a powerful tool for inferring least-biased probability distributions from limited data and a framework for the construction of complex systems theory. The maximum entropy theory of ecology (METE) describes remarkably well widely observed patterns in the distribution, abundance and energetics of individuals and taxa in relatively static ecosystems. An extension to ecosystems undergoing change in response to disturbance or natural succession (DynaMETE) is in progress. I describe the structure of both the static and the dynamic theory and show a range of comparisons with census data. I then propose a generalization of the MaxEnt approach that could provide a framework for a predictive theory of both static and dynamic, fully-coupled, eco-socio-hydrological catchment systems.
Rationalising the 'irrational': a think aloud study of discrete choice experiment responses.
Ryan, Mandy; Watson, Verity; Entwistle, Vikki
2009-03-01
Stated preference methods assume respondents' preferences are consistent with utility theory, but many empirical studies report evidence of preferences that violate utility theory. This evidence is often derived from quantitative tests that occur naturally within, or are added to, stated preference tasks. In this study, we use qualitative methods to explore three axioms of utility theory: completeness, monotonicity, and continuity. We take a novel approach, adopting a 'think aloud' technique to identify violations of the axioms of utility theory and to consider how well the quantitative tests incorporated within a discrete choice experiment are able to detect these. Results indicate that quantitative tests classify respondents as being 'irrational' when qualitative statements would indicate they are 'rational'. In particular, 'non-monotonic' responses can often be explained by respondents inferring additional information beyond what is presented in the task, and individuals who appear to adopt non-compensatory decision-making strategies do so because they rate particular attributes very highly (they are not attempting to simplify the task). The results also provide evidence of 'cost-based responses': respondents assumed tests with higher costs would be of higher quality. The value of including in-depth qualitative validation techniques in the development of stated preference tasks is shown.
Mahapatra, Ajit Kumar; Maji, Rajkishor; Maiti, Kalipada; Adhikari, Susanta Sekhar; Das Mukhopadhyay, Chitrangada; Mandal, Debasish
2014-01-07
A new BODIPY-azaindole based fluorescent sensor 1 was designed and synthesized as a new colorimetric and ratiometric fluorescent chemosensor for fluoride. The binding and sensing abilities of sensor 1 towards various anions were studied by absorption, emission and (1)H NMR titration spectroscopies. The spectral responses of 1 to fluoride in acetonitrile-water were studied: an approximately 69 nm red shift in absorption and ratiometric fluorescent response was observed. The striking light yellow to deep brown color change in ambient light and green to blue emission color change are thought to be due to the deprotonation of the indole moiety of the azaindole fluorophore. From the changes in the absorption, fluorescence, and (1)H NMR titration spectra, proton-transfer mechanisms were deduced. Density function theory and time-dependent density function theory calculations were conducted to rationalize the optical response of the sensor. Results were supported by confocal fluorescence imaging and MTT assay of live cells.
Go, Jonghyun; Nair, Pradeep R; Reddy, Bobby; Dorvel, Brian; Bashir, Rashid; Alam, Muhammad A
2012-07-24
We offer a comprehensive theory of pH response of a coupled ISFET sensor to show that the maximum achievable response is given by ΔV/ΔpH = 59 mV/pH × α, where 59 mV/pH is the intrinsic Nernst response and α an amplification factor that depends on the geometrical and electrical properties of the sensor and transducer nodes. While the intrinsic Nernst response of an electrolyte/site-binding interface is fundamental and immutable, we show that by using channels of different materials, areas, and bias conditions, the extrinsic sensor response can be increased dramatically beyond the Nernst limit. We validate the theory by measuring the pH response of a Si nanowire-nanoplate transistor pair that achieves >10 V/pH response and show the potential of the scheme to achieve (asymptotically) the theoretical lower limit of signal-to-noise ratio for a given configuration. We suggest the possibility of an even larger pH response based on recent trends in heterogeneous integration on the Si platform.
Nonlinear response from transport theory and quantum field theory at finite temperature
NASA Astrophysics Data System (ADS)
Carrington, M. E.; Defu, Hou; Kobes, R.
2001-07-01
We study the nonlinear response in weakly coupled hot φ4 theory. We obtain an expression for a quadratic shear viscous response coefficient using two different formalisms: transport theory and response theory. The transport theory calculation is done by assuming a local equilibrium form for the distribution function and expanding in the gradient of the local four dimensional velocity field. By performing a Chapman-Enskog expansion on the Boltzmann equation we obtain a hierarchy of equations for the coefficients of the expanded distribution function. To do the response theory calculation we use Zubarev's techniques in nonequilibrium statistical mechanics to derive a generalized Kubo formula. Using this formula allows us to obtain the quadratic shear viscous response from the three-point retarded Green function of the viscous shear stress tensor. We use the closed time path formalism of real time finite temperature field theory to show that this three-point function can be calculated by writing it as an integral equation involving a four-point vertex. This four-point vertex can in turn be obtained from an integral equation which represents the resummation of an infinite series of ladder and extended-ladder diagrams. The connection between transport theory and response theory is made when we show that the integral equation for this four-point vertex has exactly the same form as the equation obtained from the Boltzmann equation for the coefficient of the quadratic term of the gradient expansion of the distribution function. We conclude that calculating the quadratic shear viscous response using transport theory and keeping terms that are quadratic in the gradient of the velocity field in the Chapman-Enskog expansion of the Boltzmann equation is equivalent to calculating the quadratic shear viscous response from response theory using the next-to-linear response Kubo formula, with a vertex given by an infinite resummation of ladder and extended-ladder diagrams.
The new social marketing challenge to promote radon testing.
DiPofi, J A; LaTour, M S; Henthorne, T L
2001-01-01
As part of a project funded by the Environmental Protection Agency, exploratory qualitative analysis was conducted to gain insight into perceptions of the threat of radon in the Karst geological region (i.e., Northern Alabama, Central Tennessee, Central Kentucky). Based on health practitioner input, it was clear that the tenets of Protection Motivation Theory (PMT) and the probing afforded by focus group research would provide greatly needed theory-based insight into the public reactions (or lack thereof) to the threat posed by radon. Qualitative research findings of this project are discussed as well as preliminary recommendations are provided to advance the protection motivation theory research agenda for promoting awareness of the threat of radon and to influence appropriate response to that threat.
A generalized functional response for predators that switch between multiple prey species.
van Leeuwen, E; Brännström, Å; Jansen, V A A; Dieckmann, U; Rossberg, A G
2013-07-07
We develop a theory for the food intake of a predator that can switch between multiple prey species. The theory addresses empirical observations of prey switching and is based on the behavioural assumption that a predator tends to continue feeding on prey that are similar to the prey it has consumed last, in terms of, e.g., their morphology, defences, location, habitat choice, or behaviour. From a predator's dietary history and the assumed similarity relationship among prey species, we derive a general closed-form multi-species functional response for describing predators switching between multiple prey species. Our theory includes the Holling type II functional response as a special case and makes consistent predictions when populations of equivalent prey are aggregated or split. An analysis of the derived functional response enables us to highlight the following five main findings. (1) Prey switching leads to an approximate power-law relationship between ratios of prey abundance and prey intake, consistent with experimental data. (2) In agreement with empirical observations, the theory predicts an upper limit of 2 for the exponent of such power laws. (3) Our theory predicts deviations from power-law switching at very low and very high prey-abundance ratios. (4) The theory can predict the diet composition of a predator feeding on multiple prey species from diet observations for predators feeding only on pairs of prey species. (5) Predators foraging on more prey species will show less pronounced prey switching than predators foraging on fewer prey species, thus providing a natural explanation for the known difficulties of observing prey switching in the field. Copyright © 2013 Elsevier Ltd. All rights reserved.
Bernath, Katrin; Roschewitz, Anna
2008-11-01
The extension of contingent valuation models with an attitude-behavior based framework has been proposed in order to improve the descriptive and predictive ability of the models. This study examines the potential of the theory of planned behavior to explain willingness to pay (WTP) in a contingent valuation survey of the recreational benefits of the Zurich city forests. Two aspects of WTP responses, protest votes and bid levels, were analyzed separately. In both steps, models with and without the psychological predictors proposed by the theory of planned behavior were compared. Whereas the inclusion of the psychological predictors significantly improved explanations of protest votes, their ability to improve the performance of the model explaining bid levels was limited. The results indicate that the interpretation of bid levels as behavioral intention may not be appropriate and that the potential of the theory of planned behavior to improve contingent valuation models depends on which aspect of WTP responses is examined.
NASA Technical Reports Server (NTRS)
Arenburg, R. T.; Reddy, J. N.
1991-01-01
The micromechanical constitutive theory is used to examine the nonlinear behavior of continuous-fiber-reinforced metal-matrix composite structures. Effective lamina constitutive relations based on the Abouli micromechanics theory are presented. The inelastic matrix behavior is modeled by the unified viscoplasticity theory of Bodner and Partom. The laminate constitutive relations are incorporated into a first-order deformation plate theory. The resulting boundary value problem is solved by utilizing the finite element method. Attention is also given to computational aspects of the numerical solution, including the temporal integration of the inelastic strains and the spatial integration of bending moments. Numerical results the nonlinear response of metal matrix composites subjected to extensional and bending loads are presented.
Determination of the water vapor continuum absorption by THz-TDS and Molecular Response Theory.
Yang, Yihong; Mandehgar, Mahboubeh; Grischkowsky, D
2014-02-24
Determination of the water vapor continuum absorption from 0.35 to 1 THz is reported. The THz pulses propagate though a 137 m long humidity-controlled chamber and are measured by THz time-domain spectroscopy (THz-TDS). The average relative humidity along the entire THz path is precisely obtained by measuring the difference between transit times of the sample and reference THz pulses to an accuracy of 0.1 ps. Using the measured total absorption and the calculated resonance line absorption with the Molecular Response Theory lineshape, based on physical principles and measurements, an accurate continuum absorption is obtained within four THz absorption windows, that agrees well with the empirical theory. The absorption is significantly smaller than that obtained using the van Vleck-Weisskopf lineshape with a 750 GHz cut-off.
Surface loading of a viscoelastic earth-I. General theory
NASA Astrophysics Data System (ADS)
Tromp, Jeroen; Mitrovica, Jerry X.
1999-06-01
We present a new normal-mode formalism for computing the response of an aspherical, self-gravitating, linear viscoelastic earth model to an arbitrary surface load. The formalism makes use of recent advances in the theory of the Earth's free oscillations, and is based upon an eigenfunction expansion methodology, rather than the tradi-tional Love-number approach to surface-loading problems. We introduce a surface-load representation theorem analogous to Betti's reciprocity relation in seismology. Taking advantage of this theorem and the biorthogonality of the viscoelastic modes, we determine the complete response to a surface load in the form of a Green's function. We also demonstrate that each viscoelastic mode has its own unique energy partitioning, which can be used to characterize it. In subsequent papers, we apply the theory to spherically symmetric and aspherical earth models.
Dehbari, Samaneh Rooshanpour; Dehdari, Tahereh; Dehdari, Laleh; Mahmoudi, Maryam
2015-01-01
Given the importance of sun protection in the prevention of skin cancer, this study was designed to determine predictors of sun-protective practices among a sample of Iranian female college students based on protection motivation theory (PMT) variables. In this cross-sectional study, a total of 201 female college students in Iran University of Medical Sciences were selected. Demographic and PMT variables were assessed with a 67-item questionnaire. Multiple linear regression was used to identify demographic and PMT variables that were associated with sun-protective practices and intention. one percent of participants always wore a hat with a brim, 3.5% gloves and 15.9% sunglasses while outdoors. Only 10.9% regularly had their skin checked by a doctor. Perceived rewards, response efficacy, fear, self-efficacy and marital status were the five variables which could predict 39% variance of participants intention to perform sun-protective practices. Also, intention and response cost explained 31% of the variance of sun-protective practices. These predictive variables may be used to develop theory-based education interventions interventions to prevent skin cancer among college students.
Meissner, Christian A; Tredoux, Colin G; Parker, Janat F; MacLin, Otto H
2005-07-01
Many eyewitness researchers have argued for the application of a sequential alternative to the traditional simultaneous lineup, given its role in decreasing false identifications of innocent suspects (sequential superiority effect). However, Ebbesen and Flowe (2002) have recently noted that sequential lineups may merely bring about a shift in response criterion, having no effect on discrimination accuracy. We explored this claim, using a method that allows signal detection theory measures to be collected from eyewitnesses. In three experiments, lineup type was factorially combined with conditions expected to influence response criterion and/or discrimination accuracy. Results were consistent with signal detection theory predictions, including that of a conservative criterion shift with the sequential presentation of lineups. In a fourth experiment, we explored the phenomenological basis for the criterion shift, using the remember-know-guess procedure. In accord with previous research, the criterion shift in sequential lineups was associated with a reduction in familiarity-based responding. It is proposed that the relative similarity between lineup members may create a context in which fluency-based processing is facilitated to a greater extent when lineup members are presented simultaneously.
Wood, Pamela J
2014-09-01
Storytelling and narrative are widely used in nurse education and the value of narrative-based curricula, such as those governed by narrative pedagogy, is well recognised. Storytelling stimulates students' imagination, a central feature of narrative learning. One form of story and imagination yet to be fully considered by educators is the historical story and historical imagination. The use of historical storytelling creates a temporal dissonance between the story and reader that stimulates readers' imagination and response, and enables them to gain rich insights which can be applied to the present. Reader-response theory can support educators when using narrative and storytelling. This article presents an analysis of graduate nursing students' reader-responses to a nurse's story from the past. This narrative learning group used their historical imagination in responding to the story and prompted and challenged each other in their interpretation and in translating their responses to their current nursing practice. The article discusses this analysis within the context of reader-response theory and its potential application to narrative-based learning in nurse education. Historical stories stimulate historical imagination and offer a different frame of reference for students' development of textual competence and for applying insights to the present. Copyright © 2014 Elsevier Ltd. All rights reserved.
Martinez, Nicholas E.; Sato, Fumitaka; Omura, Seiichi; Minagar, Alireza; Alexander, J. Steven; Tsunoda, Ikuo
2012-01-01
Multiple sclerosis (MS) is a disease which can present in different clinical courses. The most common form of MS is the relapsing-remitting (RR) course, which in many cases evolves into secondary progressive (SP) disease. Autoimmune models such as experimental autoimmune encephalomyelitis (EAE) have been developed to represent the various clinical forms of MS. These models along with clinico-pathological evidence obtained from MS patients have allowed us to propose ‘1-stage’ and ‘2-stage’ disease theories to explain the transition in the clinical course of MS from RR to SP. Relapses in MS are associated with pro-inflammatory T helper (Th) 1/Th17 immune responses, while remissions are associated with anti-inflammatory Th2/regulatory T (Treg) immune responses. Based on the ‘1-stage disease’ theory, the transition from RR to SP disease occurs when the inflammatory immune response overwhelms the anti-inflammatory immune response. The ‘2-stage disease’ theory proposes that the transition from RR to SP-MS occurs when the Th2 response or some other responses overwhelm the inflammatory response resulting in the sustained production of anti-myelin antibodies, which cause continuing demyelination, neurodegeneration, and axonal loss. The Theiler’s virus model is also a 2-stage disease, where axonal degeneration precedes demyelination during the first stage, followed by inflammatory demyelination during the second stage. PMID:22633747
Di Remigio, Roberto; Beerepoot, Maarten T P; Cornaton, Yann; Ringholm, Magnus; Steindal, Arnfinn Hykkerud; Ruud, Kenneth; Frediani, Luca
2016-12-21
The study of high-order absorption properties of molecules is a field of growing importance. Quantum-chemical studies can help design chromophores with desirable characteristics. Given that most experiments are performed in solution, it is important to devise a cost-effective strategy to include solvation effects in quantum-chemical studies of these properties. We here present an open-ended formulation of self-consistent field (SCF) response theory for a molecular solute coupled to a polarizable continuum model (PCM) description of the solvent. Our formulation relies on the open-ended, density matrix-based quasienergy formulation of SCF response theory of Thorvaldsen, et al., [J. Chem. Phys., 2008, 129, 214108] and the variational formulation of the PCM, as presented by Lipparini et al., [J. Chem. Phys., 2010, 133, 014106]. Within the PCM approach to solvation, the mutual solute-solvent polarization is represented by means of an apparent surface charge (ASC) spread over the molecular cavity defining the solute-solvent boundary. In the variational formulation, the ASC is an independent, variational degree of freedom. This allows us to formulate response theory for molecular solutes in the fixed-cavity approximation up to arbitrary order and with arbitrary perturbation operators. For electric dipole perturbations, pole and residue analyses of the response functions naturally lead to the identification of excitation energies and transition moments. We document the implementation of this approach in the Dalton program package using a recently developed open-ended response code and the PCMSolver libraries and present results for one-, two-, three-, four- and five-photon absorption processes of three small molecules in solution.
Limitations of the clump-correlation theories of shear-induced turbulence suppression
NASA Astrophysics Data System (ADS)
Zhang, Y. Z.; Mahajan, S. M.
2017-05-01
The clump theory, primarily constructed by Dupree [Phys. Fluids 15, 334 (1972)] based on the moment approach and then generalized to the correlation theory [Y. Z. Zhang and S. M. Mahajan, Phys. Fluids B 5, 2000 (1993)], has long served as a basis for constructing theories of turbulence suppression by shear flow. In order to reveal the "intrinsic approximation" invoked in the clump-correlation theory, we examine a model based on two dimensional magnetized drift waves. After a rigorous derivation of the exact response function—a key to average the Green function of the system—we show that the Dupree, Zhang-Mahajan approach is recovered as the lowest order approximation in a small dimensionless parameter ϒ which is a triple product of the correlation time, wave number, and fluctuating drift velocity. The clump-correlation theory, thus, constitutes the Gaussian and lowest order non-Markovian process for a homogeneous stationary turbulence. We also provide, especially for the tokamak community, a readily usable formula to evaluate the effectiveness of shear-flow suppression; this formula pertains regardless of the specific model of correlation time.
de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Bonnaud-Antignac, Angélique; Dantan, Étienne; Sébille, Véronique
2016-10-01
The objective was to compare classical test theory and Rasch-family models derived from item response theory for the analysis of longitudinal patient-reported outcomes data with possibly informative intermittent missing items. A simulation study was performed in order to assess and compare the performance of classical test theory and Rasch model in terms of bias, control of the type I error and power of the test of time effect. The type I error was controlled for classical test theory and Rasch model whether data were complete or some items were missing. Both methods were unbiased and displayed similar power with complete data. When items were missing, Rasch model remained unbiased and displayed higher power than classical test theory. Rasch model performed better than the classical test theory approach regarding the analysis of longitudinal patient-reported outcomes with possibly informative intermittent missing items mainly for power. This study highlights the interest of Rasch-based models in clinical research and epidemiology for the analysis of incomplete patient-reported outcomes data. © The Author(s) 2013.
Flap-Lag-Torsion Stability in Forward Flight
NASA Technical Reports Server (NTRS)
Panda, B.; Chopra, I.
1985-01-01
An aeroelastic stability of three-degree flap-lag-torsion blade in forward flight is examined. Quasisteady aerodynamics with a dynamic inflow model is used. The nonlinear time dependent periodic blade response is calculated using an iterative procedure based on Floquet theory. The periodic perturbation equations are solved for stability using Floquet transition matrix theory as well as constant coefficient approximation in the fixed reference frame. Results are presented for both stiff-inplane and soft-inplane blade configurations. The effects of several parameters on blade stability are examined, including structural coupling, pitch-flap and pitch-lag coupling, torsion stiffness, steady inflow distribution, dynamic inflow, blade response solution and constant coefficient approximation.
NASA Astrophysics Data System (ADS)
Camporesi, Roberto
2016-01-01
We present an approach to the impulsive response method for solving linear constant-coefficient ordinary differential equations of any order based on the factorization of the differential operator. The approach is elementary, we only assume a basic knowledge of calculus and linear algebra. In particular, we avoid the use of distribution theory, as well as of the other more advanced approaches: Laplace transform, linear systems, the general theory of linear equations with variable coefficients and variation of parameters. The approach presented here can be used in a first course on differential equations for science and engineering majors.
AAA gunnermodel based on observer theory. [predicting a gunner's tracking response
NASA Technical Reports Server (NTRS)
Kou, R. S.; Glass, B. C.; Day, C. N.; Vikmanis, M. M.
1978-01-01
The Luenberger observer theory is used to develop a predictive model of a gunner's tracking response in antiaircraft artillery systems. This model is composed of an observer, a feedback controller and a remnant element. An important feature of the model is that the structure is simple, hence a computer simulation requires only a short execution time. A parameter identification program based on the least squares curve fitting method and the Gauss Newton gradient algorithm is developed to determine the parameter values of the gunner model. Thus, a systematic procedure exists for identifying model parameters for a given antiaircraft tracking task. Model predictions of tracking errors are compared with human tracking data obtained from manned simulation experiments. Model predictions are in excellent agreement with the empirical data for several flyby and maneuvering target trajectories.
HIV/STD risk behaviors and perceptions among rural-to-urban migrants in China.
Li, Xiaoming; Fang, Xiaoyi; Lin, Danhua; Mao, Rong; Wang, Jing; Cottrell, Lesley; Harris, Carole; Stanton, Bonita
2004-12-01
Data from 2,153 sexually active rural-to-urban migrants in China were analyzed to examine the relationship between the movement of rural-to-urban migration and increased HIV/STD (sexually transmitted disease) risk and the applicability of constructs of a Western-based theory of behavioral change to the study population. Measurements included migrant mobility, sexual risk, and the seven constructs of the protection motivation theory (PMT). Data in the current study suggest that high mobility among rural-to-urban migrants was associated with increased sexual risk. The PMT constructs are applicable in identifying perceptions and attitudes associated with sexual risk behaviors in this culturally distinct population. Increased sexual risk was associated with increased perceptions of extrinsic rewards, intrinsic rewards, and response cost. Also consistent with PMT, increased sexual risk was associated with perceptions of decreased severity, vulnerability, response efficacy, and self-efficacy. After controlling for a number of key confounding factors, all seven PMT constructs were associated with sexual risk in the manner posited by the theory. The association between mobility and sexual risk underscores the importance of effective HIV/STD prevention efforts among this vulnerable population. The social cognitive theories including the PMT may form a logical base for prevention intervention programs targeting rural-to-urban migrants in China.
Renmans, Dimitri; Holvoet, Nathalie; Criel, Bart
2017-09-03
Increased attention on "complexity" in health systems evaluation has resulted in many different methodological responses. Theory-driven evaluations and systems thinking are two such responses that aim for better understanding of the mechanisms underlying given outcomes. Here, we studied the implementation of a performance-based financing intervention by the Belgian Technical Cooperation in Western Uganda to illustrate a methodological strategy of combining these two approaches. We utilized a systems dynamics tool called causal loop diagramming (CLD) to generate hypotheses feeding into a theory-driven evaluation. Semi-structured interviews were conducted with 30 health workers from two districts (Kasese and Kyenjojo) and with 16 key informants. After CLD, we identified three relevant hypotheses: "success to the successful", "growth and underinvestment", and "supervision conundrum". The first hypothesis leads to increasing improvements in performance, as better performance leads to more incentives, which in turn leads to better performance. The latter two hypotheses point to potential bottlenecks. Thus, the proposed methodological strategy was a useful tool for identifying hypotheses that can inform a theory-driven evaluation. The hypotheses are represented in a comprehensible way while highlighting the underlying assumptions, and are more easily falsifiable than hypotheses identified without using CLD.
ERIC Educational Resources Information Center
Dimitrov, Dimiter M.
2017-01-01
This article offers an approach to examining differential item functioning (DIF) under its item response theory (IRT) treatment in the framework of confirmatory factor analysis (CFA). The approach is based on integrating IRT- and CFA-based testing of DIF and using bias-corrected bootstrap confidence intervals with a syntax code in Mplus.
Investigation of IRT-Based Equating Methods in the Presence of Outlier Common Items
ERIC Educational Resources Information Center
Hu, Huiqin; Rogers, W. Todd; Vukmirovic, Zarko
2008-01-01
Common items with inconsistent b-parameter estimates may have a serious impact on item response theory (IRT)--based equating results. To find a better way to deal with the outlier common items with inconsistent b-parameters, the current study investigated the comparability of 10 variations of four IRT-based equating methods (i.e., concurrent…
Active Parenting Now: Program Kit.
ERIC Educational Resources Information Center
Popkin, Michael H.
Based largely on the theories of Alfred Adler and Rudolf Dreikurs, this parent education curriculum is a video-based interactive learning experience that teaches a comprehensive model of parenting to parents of children ages 5 to 12 years. The kit provides parents with the skills needed to help their children develop courage, responsibility, and…
Predicting the Probability for Faculty Adopting an Audience Response System in Higher Education
ERIC Educational Resources Information Center
Chan, Tan Fung Ivan; Borja, Marianne; Welch, Brett; Batiuk, Mary Ellen
2016-01-01
Instructional technologies can be effective tools to foster student engagement, but university faculty may be reluctant to integrate innovative and evidence-based modern learning technologies into instruction. Based on Rogers' diffusion of innovation theory, this quantitative, nonexperimental, one-shot cross-sectional survey determined what…
Membrane-Based Characterization of a Gas Component — A Transient Sensor Theory
Lazik, Detlef
2014-01-01
Based on a multi-gas solution-diffusion problem for a dense symmetrical membrane this paper presents a transient theory of a planar, membrane-based sensor cell for measuring gas from both initial conditions: dynamic and thermodynamic equilibrium. Using this theory, the ranges for which previously developed, simpler approaches are valid will be discussed; these approaches are of vital interest for membrane-based gas sensor applications. Finally, a new theoretical approach is introduced to identify varying gas components by arranging sensor cell pairs resulting in a concentration independent gas-specific critical time. Literature data for the N2, O2, Ar, CH4, CO2, H2 and C4H10 diffusion coefficients and solubilities for a polydimethylsiloxane membrane were used to simulate gas specific sensor responses. The results demonstrate the influence of (i) the operational mode; (ii) sensor geometry and (iii) gas matrices (air, Ar) on that critical time. Based on the developed theory the case-specific suitable membrane materials can be determined and both operation and design options for these sensors can be optimized for individual applications. The results of mixing experiments for different gases (O2, CO2) in a gas matrix of air confirmed the theoretical predictions. PMID:24608004
A Model for Evidence Accumulation in the Lexical Decision Task
ERIC Educational Resources Information Center
Wagenmakers, Eric-Jan; Steyvers, Mark; Raaijmakers, Jeroen G. W.; Shiffrin, Richard M.; van Rijn, Hedderik; Zeelenberg, Rene
2004-01-01
We present a new model for lexical decision, REM-LD, that is based on REM theory (e.g., Shiffrin & Steyvers, 1997). REM-LD uses a principled (i.e., Bayes' rule) decision process that simultaneously considers the diagnosticity of the evidence for the 'WORD' response and the 'NONWORD' response. The model calculates the odds ratio that the presented…
ERIC Educational Resources Information Center
Köhler, Carmen; Pohl, Steffi; Carstensen, Claus H.
2015-01-01
When competence tests are administered, subjects frequently omit items. These missing responses pose a threat to correctly estimating the proficiency level. Newer model-based approaches aim to take nonignorable missing data processes into account by incorporating a latent missing propensity into the measurement model. Two assumptions are typically…
A Person Fit Test for IRT Models for Polytomous Items
ERIC Educational Resources Information Center
Glas, C. A. W.; Dagohoy, Anna Villa T.
2007-01-01
A person fit test based on the Lagrange multiplier test is presented for three item response theory models for polytomous items: the generalized partial credit model, the sequential model, and the graded response model. The test can also be used in the framework of multidimensional ability parameters. It is shown that the Lagrange multiplier…
ERIC Educational Resources Information Center
Camporesi, Roberto
2011-01-01
We present an approach to the impulsive response method for solving linear constant-coefficient ordinary differential equations based on the factorization of the differential operator. The approach is elementary, we only assume a basic knowledge of calculus and linear algebra. In particular, we avoid the use of distribution theory, as well as of…
A Note on the Reliability Coefficients for Item Response Model-Based Ability Estimates
ERIC Educational Resources Information Center
Kim, Seonghoon
2012-01-01
Assuming item parameters on a test are known constants, the reliability coefficient for item response theory (IRT) ability estimates is defined for a population of examinees in two different ways: as (a) the product-moment correlation between ability estimates on two parallel forms of a test and (b) the squared correlation between the true…
Covariates of the Rating Process in Hierarchical Models for Multiple Ratings of Test Items
ERIC Educational Resources Information Center
Mariano, Louis T.; Junker, Brian W.
2007-01-01
When constructed response test items are scored by more than one rater, the repeated ratings allow for the consideration of individual rater bias and variability in estimating student proficiency. Several hierarchical models based on item response theory have been introduced to model such effects. In this article, the authors demonstrate how these…
Wyrwich, KW; Phillips, GA; Vollmer, T; Guo, S
2016-01-01
Background Investigations using classical test theory support the psychometric properties of the original version of the Multiple Sclerosis Impact Scale (MSIS-29v1), a disease-specific measure of multiple sclerosis (MS) impact (physical and psychological subscales). Later, assessments of the MSIS-29v1 in an MS community-based sample using Rasch analysis led to revisions of the instrument’s response options (MSIS-29v2). Objective The objective of this paper is to evaluate the psychometric properties of the MSIS-29v1 in a clinical trial cohort of relapsing–remitting MS patients (RRMS). Methods Data from 600 patients with RRMS enrolled in the SELECT clinical trial were used. Assessments were performed at baseline and at Weeks 12, 24, and 52. In addition to traditional psychometric analyses, Item Response Theory (IRT) and Rasch analysis were used to evaluate the measurement properties of the MSIS-29v1. Results Both MSIS-29v1 subscales demonstrated strong reliability, construct validity, and responsiveness. The IRT and Rasch analysis showed overall support for response category threshold ordering, person-item fit, and item fit for both subscales. Conclusions Both MSIS-29v1 subscales demonstrated robust measurement properties using classical, IRT, and Rasch techniques. Unlike previous research using a community-based sample, the MSIS-29v1 was found to be psychometrically sound to assess physical and psychological impairments in a clinical trial sample of patients with RRMS. PMID:28607741
Bacci, E D; Wyrwich, K W; Phillips, G A; Vollmer, T; Guo, S
2016-01-01
Investigations using classical test theory support the psychometric properties of the original version of the Multiple Sclerosis Impact Scale (MSIS-29v1), a disease-specific measure of multiple sclerosis (MS) impact (physical and psychological subscales). Later, assessments of the MSIS-29v1 in an MS community-based sample using Rasch analysis led to revisions of the instrument's response options (MSIS-29v2). The objective of this paper is to evaluate the psychometric properties of the MSIS-29v1 in a clinical trial cohort of relapsing-remitting MS patients (RRMS). Data from 600 patients with RRMS enrolled in the SELECT clinical trial were used. Assessments were performed at baseline and at Weeks 12, 24, and 52. In addition to traditional psychometric analyses, Item Response Theory (IRT) and Rasch analysis were used to evaluate the measurement properties of the MSIS-29v1. Both MSIS-29v1 subscales demonstrated strong reliability, construct validity, and responsiveness. The IRT and Rasch analysis showed overall support for response category threshold ordering, person-item fit, and item fit for both subscales. Both MSIS-29v1 subscales demonstrated robust measurement properties using classical, IRT, and Rasch techniques. Unlike previous research using a community-based sample, the MSIS-29v1 was found to be psychometrically sound to assess physical and psychological impairments in a clinical trial sample of patients with RRMS.
Leadbeater, Bonnie J; Thompson, Kara; Sukhawathanakul, Paweena
2016-12-01
Testing the theories that form the basis of prevention programs can enhance our understanding of behavioral change and inform the development, coordination, and adaptation of prevention programs. However, theories of change showing the linkages from intervention program components to risk or protective factors to desired outcomes across time are rarely specified or tested. In this 2-year longitudinal study, we test the theory that increases in two protective factors (i.e., children's prosocial leadership and their teachers' expectations of social responsibility) targeted by the WITS Programs (Walk Away, Ignore, Talk it Out, and Seek Help) would be associated with declines in peer victimization, aggression, and emotional problems. Participants included Canadian students, in grades 1-4 at baseline (n = 1329) and their parents and teachers. Consistent with our theory of change, variability in program implementation (adherence and integration) and in children's use of program skills (child responsiveness) are related to increases in both protective factors. Increases in these protective factors are associated with subsequent declines in children's aggression, victimization, and emotional problems. We discuss how enhancement of these protective factors may operate to improve child outcomes and the need for theory-based research to refine and improve the effectiveness of intervention strategies and to improve program scale-up. © Society for Community Research and Action 2016.
Stability of Mixed-Strategy-Based Iterative Logit Quantal Response Dynamics in Game Theory
Zhuang, Qian; Di, Zengru; Wu, Jinshan
2014-01-01
Using the Logit quantal response form as the response function in each step, the original definition of static quantal response equilibrium (QRE) is extended into an iterative evolution process. QREs remain as the fixed points of the dynamic process. However, depending on whether such fixed points are the long-term solutions of the dynamic process, they can be classified into stable (SQREs) and unstable (USQREs) equilibriums. This extension resembles the extension from static Nash equilibriums (NEs) to evolutionary stable solutions in the framework of evolutionary game theory. The relation between SQREs and other solution concepts of games, including NEs and QREs, is discussed. Using experimental data from other published papers, we perform a preliminary comparison between SQREs, NEs, QREs and the observed behavioral outcomes of those experiments. For certain games, we determine that SQREs have better predictive power than QREs and NEs. PMID:25157502
Nielsen, Ann
2016-07-01
Concept-based learning is used increasingly in nursing education to support the organization, transfer, and retention of knowledge. Concept-based learning activities (CBLAs) have been used in clinical education to explore key aspects of the patient situation and principles of nursing care, without responsibility for total patient care. The nature of best practices in teaching and the resultant learning are not well understood. The purpose of this multiple-case study research was to explore and describe concept-based learning in the context of clinical education in inpatient settings. Four clinical groups (each a case) were observed while they used CBLAs in the clinical setting. Major findings include that concept-based learning fosters deep learning, connection of theory with practice, and clinical judgment. Strategies used to support learning, major teaching-learning foci, and preconditions for concept-based teaching and learning will be described. Concept-based learning is promising to support integration of theory with practice and clinical judgment through application experiences with patients. [J Nurs Educ. 2016;55(7):365-371.]. Copyright 2016, SLACK Incorporated.
The l z ( p ) * Person-Fit Statistic in an Unfolding Model Context.
Tendeiro, Jorge N
2017-01-01
Although person-fit analysis has a long-standing tradition within item response theory, it has been applied in combination with dominance response models almost exclusively. In this article, a popular log likelihood-based parametric person-fit statistic under the framework of the generalized graded unfolding model is used. Results from a simulation study indicate that the person-fit statistic performed relatively well in detecting midpoint response style patterns and not so well in detecting extreme response style patterns.
Time-dependent mean-field theory for x-ray near-edge spectroscopy
NASA Astrophysics Data System (ADS)
Bertsch, G. F.; Lee, A. J.
2014-02-01
We derive equations of motion for calculating the near-edge x-ray absorption spectrum in molecules and condensed matter, based on a two-determinant approximation and Dirac's variational principle. The theory provides an exact solution for the linear response when the Hamiltonian or energy functional has only diagonal interactions in some basis. We numerically solve the equations to compare with the Mahan-Nozières-De Dominicis theory of the edge singularity in metallic conductors. Our extracted power-law exponents are similar to those of the analytic theory, but are not in quantitative agreement. The calculational method can be readily generalized to treat Kohn-Sham Hamiltonians with electron-electron interactions derived from correlation-exchange potentials.
Managing for resilience: an information theory-based ...
Ecosystems are complex and multivariate; hence, methods to assess the dynamics of ecosystems should have the capacity to evaluate multiple indicators simultaneously. Most research on identifying leading indicators of regime shifts has focused on univariate methods and simple models which have limited utility when evaluating real ecosystems, particularly because drivers are often unknown. We discuss some common univariate and multivariate approaches for detecting critical transitions in ecosystems and demonstrate their capabilities via case studies. Synthesis and applications. We illustrate the utility of an information theory-based index for assessing ecosystem dynamics. Trends in this index also provide a sentinel of both abrupt and gradual transitions in ecosystems. In response to the need to identify leading indicators of regime shifts in ecosystems, our research compares traditional indicators and Fisher information, an information theory based method, by examining four case study systems. Results demonstrate the utility of methods and offers great promise for quantifying and managing for resilience.
Toward a theory of leadership and state building.
Myerson, Roger B
2011-12-27
We present a theory of the state based on political leadership and reputational equilibria. A political leader first needs a reputation for reliably rewarding loyal supporters. Reputational expectations between political leaders and their supporters become the fundamental political laws on which the enforcement of all other constitutional laws may be based. Successful democratic development requires a plentiful supply of leaders who have good reputations for using public funds responsibly to serve the public at large and not just giving jobs to their active supporters. It is argued that decentralized democracy may be the best way to improve the chances for successful democracy.
ERIC Educational Resources Information Center
Aaro, Leif E.; Breivik, Kyrre; Klepp, Knut-Inge; Kaaya, Sylvia; Onya, Hans E.; Wubs, Annegreet; Helleve, Arnfinn; Flisher, Alan J.
2011-01-01
A 14-item human immunodeficiency virus/acquired immunodeficiency syndrome knowledge scale was used among school students in 80 schools in 3 sites in Sub-Saharan Africa (Cape Town and Mankweng, South Africa, and Dar es Salaam, Tanzania). For each item, an incorrect or don't know response was coded as 0 and correct response as 1. Exploratory factor…
NASA Astrophysics Data System (ADS)
Martin, Alexandre; Torrent, Marc; Caracas, Razvan
2015-03-01
A formulation of the response of a system to strain and electric field perturbations in the pseudopotential-based density functional perturbation theory (DFPT) has been proposed by D.R Hamman and co-workers. It uses an elegant formalism based on the expression of DFT total energy in reduced coordinates, the key quantity being the metric tensor and its first and second derivatives. We propose to extend this formulation to the Projector Augmented-Wave approach (PAW). In this context, we express the full elastic tensor including the clamped-atom tensor, the atomic-relaxation contributions (internal stresses) and the response to electric field change (piezoelectric tensor and effective charges). With this we are able to compute the elastic tensor for all materials (metals and insulators) within a fully analytical formulation. The comparison with finite differences calculations on simple systems shows an excellent agreement. This formalism has been implemented in the plane-wave based DFT ABINIT code. We apply it to the computation of elastic properties and seismic-wave velocities of iron with impurity elements. By analogy with the materials contained in meteorites, tested impurities are light elements (H, O, C, S, Si).
Theory-Based Formative Research on an Anti-Cyberbullying Victimization Intervention Message.
Savage, Matthew W; Deiss, Douglas M; Roberto, Anthony J; Aboujaoude, Elias
2017-02-01
Cyberbullying is a common byproduct of the digital revolution with serious consequences to victims. Unfortunately, there is a dearth of empirically based methods to confront it. This study used social cognitive theory to design and test an intervention message aimed at persuading college students to abstain from retaliation, seek social support, save evidence, and notify authorities-important victim responses identified and recommended in previous research. Using a posttest-only control group design, this study tested the effectiveness of an intervention message in changing college students' perceived susceptibility to and perceived severity of cyberbullying as well as their self-efficacy, response efficacy, attitudes, and behavioral intentions toward each recommended response in future episodes of cyberbullying. Results indicated that the intervention message caused participants in the experimental condition to report significantly higher susceptibility, but not perceived severity, to cyberbullying than those in the control condition. The intervention message also caused expected changes in all outcomes except self-efficacy for not retaliating and in all outcomes for seeking social support, saving evidence, and notifying an authority. Implications for message design and future research supporting evidence-based anti-cyberbullying health communication campaigns are discussed.
Transitional clerkship: an experiential course based on workplace learning theory.
Chittenden, Eva H; Henry, Duncan; Saxena, Varun; Loeser, Helen; O'Sullivan, Patricia S
2009-07-01
Starting clerkships is anxiety provoking for medical students. To ease the transition from preclerkship to clerkship curricula, schools offer classroom-based courses which may not be the best model for preparing learners. Drawing from workplace learning theory, the authors developed a seven-day transitional clerkship (TC) in 2007 at the University of California, San Francisco School of Medicine in which students spent half of the course in the hospital, learning routines and logistics of the wards along with their roles and responsibilities as members of ward teams. Twice, they admitted and followed a patient into the next day as part of a shadow team that had no patient-care responsibilities. Dedicated preceptors gave feedback on oral presentations and patient write-ups. Satisfaction with the TC was higher than with the previous year's classroom-based course. TC students felt clearer about their roles and more confident in their abilities as third-year students compared with previous students. TC students continued to rate the transitional course highly after their first clinical rotation. Preceptors were enthusiastic about the course and expressed willingness to commit to future TC preceptorships. The transitional course models an approach to translating workplace learning theory into practice and demonstrates improved satisfaction, better understanding of roles, and increased confidence among new third-year students.
Utilizing measure-based feedback in control-mastery theory: A clinical error.
Snyder, John; Aafjes-van Doorn, Katie
2016-09-01
Clinical errors and ruptures are an inevitable part of clinical practice. Often times, therapists are unaware that a clinical error or rupture has occurred, leaving no space for repair, and potentially leading to patient dropout and/or less effective treatment. One way to overcome our blind spots is by frequently and systematically collecting measure-based feedback from the patient. Patient feedback measures that focus on the process of psychotherapy such as the Patient's Experience of Attunement and Responsiveness scale (PEAR) can be used in conjunction with treatment outcome measures such as the Outcome Questionnaire 45.2 (OQ-45.2) to monitor the patient's therapeutic experience and progress. The regular use of these types of measures can aid clinicians in the identification of clinical errors and the associated patient deterioration that might otherwise go unnoticed and unaddressed. The current case study describes an instance of clinical error that occurred during the 2-year treatment of a highly traumatized young woman. The clinical error was identified using measure-based feedback and subsequently understood and addressed from the theoretical standpoint of the control-mastery theory of psychotherapy. An alternative hypothetical response is also presented and explained using control-mastery theory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rüger, Robert, E-mail: rueger@scm.com; Department of Theoretical Chemistry, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam; Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Linnéstr. 2, 04103 Leipzig
2016-05-14
We propose a new method of calculating electronically excited states that combines a density functional theory based ground state calculation with a linear response treatment that employs approximations used in the time-dependent density functional based tight binding (TD-DFTB) approach. The new method termed time-dependent density functional theory TD-DFT+TB does not rely on the DFTB parametrization and is therefore applicable to systems involving all combinations of elements. We show that the new method yields UV/Vis absorption spectra that are in excellent agreement with computationally much more expensive TD-DFT calculations. Errors in vertical excitation energies are reduced by a factor of twomore » compared to TD-DFTB.« less
Ding, Xiao Pan; Wu, Si Jia; Liu, Jiangang; Fu, Genyue; Lee, Kang
2017-09-21
The present study examined how different brain regions interact with each other during spontaneous honest vs. dishonest communication. More specifically, we took a complex network approach based on the graph-theory to analyze neural response data when children are spontaneously engaged in honest or dishonest acts. Fifty-nine right-handed children between 7 and 12 years of age participated in the study. They lied or told the truth out of their own volition. We found that lying decreased both the global and local efficiencies of children's functional neural network. This finding, for the first time, suggests that lying disrupts the efficiency of children's cortical network functioning. Further, it suggests that the graph theory based network analysis is a viable approach to study the neural development of deception.
A normal mode treatment of semi-diurnal body tides on an aspherical, rotating and anelastic Earth
NASA Astrophysics Data System (ADS)
Lau, Harriet C. P.; Yang, Hsin-Ying; Tromp, Jeroen; Mitrovica, Jerry X.; Latychev, Konstantin; Al-Attar, David
2015-08-01
Normal mode treatments of the Earth's body tide response were developed in the 1980s to account for the effects of Earth rotation, ellipticity, anelasticity and resonant excitation within the diurnal band. Recent space-geodetic measurements of the Earth's crustal displacement in response to luni-solar tidal forcings have revealed geographical variations that are indicative of aspherical deep mantle structure, thus providing a novel data set for constraining deep mantle elastic and density structure. In light of this, we make use of advances in seismic free oscillation literature to develop a new, generalized normal mode theory for the tidal response within the semi-diurnal and long-period tidal band. Our theory involves a perturbation method that permits an efficient calculation of the impact of aspherical structure on the tidal response. In addition, we introduce a normal mode treatment of anelasticity that is distinct from both earlier work in body tides and the approach adopted in free oscillation seismology. We present several simple numerical applications of the new theory. First, we compute the tidal response of a spherically symmetric, non-rotating, elastic and isotropic Earth model and demonstrate that our predictions match those based on standard Love number theory. Second, we compute perturbations to this response associated with mantle anelasticity and demonstrate that the usual set of seismic modes adopted for this purpose must be augmented by a family of relaxation modes to accurately capture the full effect of anelasticity on the body tide response. Finally, we explore aspherical effects including rotation and we benchmark results from several illustrative case studies of aspherical Earth structure against independent finite-volume numerical calculations of the semi-diurnal body tide response. These tests confirm the accuracy of the normal mode methodology to at least the level of numerical error in the finite-volume predictions. They also demonstrate that full coupling of normal modes, rather than group coupling, is necessary for accurate predictions of the body tide response.
Naïve conceptions about multimedia learning: a study on primary school textbooks
Colombo, Barbara; Antonietti, Alessandro
2013-01-01
HIGHLIGHTS This interview study explores beliefs about the instructional role of illustrationsWe compared illustrators', teachers', students' and common people's ideasParticipants' responses were internally coherent and close to multimedia learning theoryWe propose and discuss an integrated multimedia learning model An interview study, based on specific pictures taken from textbooks used in primary schools, was carried out to investigate illustrators', teachers', students', and common people's beliefs about the role that illustrations play in facilitating learning. Participants' responses were internally coherent, indicating a systematic nature of the underlying naïve conceptions. Findings disprove Mayer's pessimistic claim that laypersons' conceptions of multimedia learning fail to match experimentally supported principles and theories. On the contrary, interviewees spontaneously came very close to the multimedia learning theory, which states that students learn better from pictures, which fit specific cognitive principles. Implications for school instruction are highlighted. PMID:23908636
Naïve conceptions about multimedia learning: a study on primary school textbooks.
Colombo, Barbara; Antonietti, Alessandro
2013-01-01
HIGHLIGHTSThis interview study explores beliefs about the instructional role of illustrationsWe compared illustrators', teachers', students' and common people's ideasParticipants' responses were internally coherent and close to multimedia learning theoryWe propose and discuss an integrated multimedia learning model An interview study, based on specific pictures taken from textbooks used in primary schools, was carried out to investigate illustrators', teachers', students', and common people's beliefs about the role that illustrations play in facilitating learning. Participants' responses were internally coherent, indicating a systematic nature of the underlying naïve conceptions. Findings disprove Mayer's pessimistic claim that laypersons' conceptions of multimedia learning fail to match experimentally supported principles and theories. On the contrary, interviewees spontaneously came very close to the multimedia learning theory, which states that students learn better from pictures, which fit specific cognitive principles. Implications for school instruction are highlighted.
Outlines of a multiple trace theory of temporal preparation.
Los, Sander A; Kruijne, Wouter; Meeter, Martijn
2014-01-01
We outline a new multiple trace theory of temporal preparation (MTP), which accounts for behavior in reaction time (RT) tasks in which the participant is presented with a warning stimulus (S1) followed by a target stimulus (S2) that requires a speeded response. The theory assumes that during the foreperiod (FP; the S1-S2 interval) inhibition is applied to prevent premature response, while a wave of activation occurs upon the presentation of S2. On each trial, these actions are stored in a separate memory trace, which, jointly with earlier formed memory traces, starts contributing to preparation on subsequent trials. We show that MTP accounts for classic effects in temporal preparation, including mean RT-FP functions observed under a variety of FP distributions and asymmetric sequential effects. We discuss the advantages of MTP over other accounts of these effects (trace-conditioning and hazard-based explanations) and suggest a critical experiment to empirically distinguish among them.
Domain-specific reasoning: social contracts, cheating, and perspective change.
Gigerenzer, G; Hug, K
1992-05-01
What counts as human rationality: reasoning processes that embody content-independent formal theories, such as propositional logic, or reasoning processes that are well designed for solving important adaptive problems? Most theories of human reasoning have been based on content-independent formal rationality, whereas adaptive reasoning, ecological or evolutionary, has been little explored. We elaborate and test an evolutionary approach. Cosmides' (1989) social contract theory, using the Wason selection task. In the first part, we disentangle the theoretical concept of a "social contract" from that of a "cheater-detection algorithm". We demonstrate that the fact that a rule is perceived as a social contract--or a conditional permission or obligation, as Cheng and Holyoak (1985) proposed--is not sufficient to elicit Cosmides' striking results, which we replicated. The crucial issue is not semantic (the meaning of the rule), but pragmatic: whether a person is cued into the perspective of a party who can be cheated. In the second part, we distinguish between social contracts with bilateral and unilateral cheating options. Perspective change in contracts with bilateral cheating options turns P & not-Q responses into not-P & Q responses. The results strongly support social contract theory, contradict availability theory, and cannot be accounted for by pragmatic reasoning schema theory, which lacks the pragmatic concepts of perspectives and cheating detection.
The problem with outcomes-based curricula in medical education: insights from educational theory.
Rees, Charlotte E
2004-06-01
Educators across the world are charged with the responsibility of producing core learning outcomes for medical curricula. However, much educational theory exists which deliberates the value of learning outcomes in education. This paper aims to discuss the problems surrounding outcomes-based curricula in medical education, using insights from educational theory. The paper begins with a discussion of the traditions, values and ideologies of medical curricula. It continues by analysing the issue of control within the curriculum and argues that curriculum designers and teachers control product-orientated curricula, leading to student disempowerment. The paper debates outcomes-based curricula from an ideological perspective and argues that learning outcomes cannot specify exactly what is to be achieved as a result of learning. The paper argues that medical schools should adopt a model for co-operative control of the curriculum, thus empowering learners. The paper also suggests that medical educators should determine the value of precise learning outcomes before blindly adopting an outcomes-based model.
ERIC Educational Resources Information Center
Chan, Randolph C. H.; Mak, Winnie W. S.; Pang, Ingrid H. Y.; Wong, Samuel Y. S.; Tang, Wai Kwong; Lau, Joseph T. F.; Woo, Jean; Lee, Diana T. F.; Cheung, Fanny M.
2018-01-01
The present study examined whether, when, and how motivational messaging can boost the response rate of postal surveys for physicians based on Higgin's regulatory focus theory, accounting for its cost-effectiveness. A three-arm, blinded, randomized controlled design was used. A total of 3,270 doctors were randomly selected from the registration…
ERIC Educational Resources Information Center
Vineyard, Lynn
2010-01-01
This pilot study describes elementary teachers' use of collaborative inquiry as a strategy for assessing Response to Instruction and Intervention (RtI [superscript 2]) in reading for an English Learner student. The design of the study was based on the sociocultural theory that assessment practices shape teachers' understanding of students and of…
Mathematical modeling of the aerodynamic characteristics in flight dynamics
NASA Technical Reports Server (NTRS)
Tobak, M.; Chapman, G. T.; Schiff, L. B.
1984-01-01
Basic concepts involved in the mathematical modeling of the aerodynamic response of an aircraft to arbitrary maneuvers are reviewed. The original formulation of an aerodynamic response in terms of nonlinear functionals is shown to be compatible with a derivation based on the use of nonlinear functional expansions. Extensions of the analysis through its natural connection with ideas from bifurcation theory are indicated.
ERIC Educational Resources Information Center
Camporesi, Roberto
2016-01-01
We present an approach to the impulsive response method for solving linear constant-coefficient ordinary differential equations of any order based on the factorization of the differential operator. The approach is elementary, we only assume a basic knowledge of calculus and linear algebra. In particular, we avoid the use of distribution theory, as…
A Cultural Historical Theoretical Perspective of Discourse and Design in the Science Classroom
ERIC Educational Resources Information Center
Adams, Megan
2015-01-01
Flavio Azevedo, Peggy Martalock and Tugba Keser have initiated an important conversation in science education as they use sociocultural theory to introduce design based scenarios into the science classroom. This response seeks to expand Azevedo, Martalock and Keser's article "The discourse of design-based science classroom activities" by…
Ethics in Field-Based Research: Contractual and Relational Responsibilities.
ERIC Educational Resources Information Center
Brickhouse, Nancy W.
The desire to abolish the gap between research theory and classroom practice has sparked an increasing interest in field-based research among science educators. Although most researchers are aware of the standard meanings of informed consent and confidentiality, and there are some codes of ethical principles published by such groups as the…
Experiential, Team-Based Learning in a Baccalaureate Social Work Research Course
ERIC Educational Resources Information Center
Venema, Rachel; Meerman, Judi Ravenhorst; Hossink, Kristin
2015-01-01
This article describes student responses to a BSW research course framed by experiential learning theory to engage the community and offer applied research practice. The study finds that students generally express overall satisfaction with the research course and describe perceptions of learning gains when involved in a team-based research project…
Optimal and Nonoptimal Computer-Based Test Designs for Making Pass-Fail Decisions
ERIC Educational Resources Information Center
Hambleton, Ronald K.; Xing, Dehui
2006-01-01
Now that many credentialing exams are being routinely administered by computer, new computer-based test designs, along with item response theory models, are being aggressively researched to identify specific designs that can increase the decision consistency and accuracy of pass-fail decisions. The purpose of this study was to investigate the…
ERIC Educational Resources Information Center
Yang, Xiangdong; Poggio, John C.; Glasnapp, Douglas R.
2006-01-01
The effects of five ability estimators, that is, maximum likelihood estimator, weighted likelihood estimator, maximum a posteriori, expected a posteriori, and Owen's sequential estimator, on the performances of the item response theory-based adaptive classification procedure on multiple categories were studied via simulations. The following…
ERIC Educational Resources Information Center
Levy, Roy; Xu, Yuning; Yel, Nedim; Svetina, Dubravka
2015-01-01
The standardized generalized dimensionality discrepancy measure and the standardized model-based covariance are introduced as tools to critique dimensionality assumptions in multidimensional item response models. These tools are grounded in a covariance theory perspective and associated connections between dimensionality and local independence.…
Sequential Objective Structured Clinical Examination based on item response theory in Iran.
Hejri, Sara Mortaz; Jalili, Mohammad
2017-01-01
In a sequential objective structured clinical examination (OSCE), all students initially take a short screening OSCE. Examinees who pass are excused from further testing, but an additional OSCE is administered to the remaining examinees. Previous investigations of sequential OSCE were based on classical test theory. We aimed to design and evaluate screening OSCEs based on item response theory (IRT). We carried out a retrospective observational study. At each station of a 10-station OSCE, the students' performance was graded on a Likert-type scale. Since the data were polytomous, the difficulty parameters, discrimination parameters, and students' ability were calculated using a graded response model. To design several screening OSCEs, we identified the 5 most difficult stations and the 5 most discriminative ones. For each test, 5, 4, or 3 stations were selected. Normal and stringent cut-scores were defined for each test. We compared the results of each of the 12 screening OSCEs to the main OSCE and calculated the positive and negative predictive values (PPV and NPV), as well as the exam cost. A total of 253 students (95.1%) passed the main OSCE, while 72.6% to 94.4% of examinees passed the screening tests. The PPV values ranged from 0.98 to 1.00, and the NPV values ranged from 0.18 to 0.59. Two tests effectively predicted the results of the main exam, resulting in financial savings of 34% to 40%. If stations with the highest IRT-based discrimination values and stringent cut-scores are utilized in the screening test, sequential OSCE can be an efficient and convenient way to conduct an OSCE.
Educational Leadership: A Problem-Based Approach. Second Edition.
ERIC Educational Resources Information Center
Cunningham, William G.; Cordeiro, Paula A.
Chapter titles of this book on educational leadership reflect its contents: (1) "Administrative Theory and Leadership Responsibility"; (2) "Context and Perspective for Educational Leaders"; (3) "School Reform"; (4) "Cultural Diversity and Community Relations"; (5) "School District Organizational…
Integrated Ecology: The Process of Counseling with Nature.
ERIC Educational Resources Information Center
Cohen, Michael J.
1994-01-01
Discusses the theory behind an applied ecopsychology program based on Integrated Ecology. Integrated Ecology uses personal sensory contact with natural areas, in backyards, parks, or back country to unleash natural ability to relate and survive responsibly. (LZ)
Development of a health literacy assessment for young adult college students: a pilot study.
Harper, Raquel
2014-01-01
The purpose of this study was to develop a comprehensive health literacy assessment tool for young adult college students. Participants were 144 undergraduate students. Two hundred and twenty-nine questions were developed, which were based on concepts identified by the US Department of Health and Human Services, the World Health Organization, and health communication scholars. Four health education experts reviewed this pool of items and helped select 87 questions for testing. Students completed an online assessment consisting of these 87 questions in June and October of 2012. Item response theory and goodness-of-fit values were used to help eliminate nonperforming questions. Fifty-one questions were selected based on good item response theory discrimination parameter values. The instrument has 51 questions that look promising for measuring health literacy in college students, but needs additional testing with a larger student population to see how these questions continue to perform.
NASA Astrophysics Data System (ADS)
Li, Liyang; Wang, Jun; Wang, Jiafu; Ma, Hua; Du, Hongliang; Zhang, Jieqiu; Qu, Shaobo; Xu, Zhuo
2016-04-01
Based on effective medium theory and dielectric resonator theory, we propose the design of reconfigurable all-dielectric metamaterial frequency selective surfaces (FSSs) using high-permittivity ceramics. The FSS is composed of ceramic resonators with different band stop responses under front and side incidences. By mechanically tuning the orientation of the ceramic resonators, reconfigurable electromagnetic (EM) responses between two adjacent stopbands can be achieved. The two broad stopbands originate from the first two resonant modes of the ceramic resonators. As an example, a reconfigurable FSS composed of cross-shaped ceramic resonators is demonstrated. Both numerical and experimental results show that the FSS can switch between two consecutive stopbands in 3.55-4.60 GHz and 4.54-4.94 GHz. The design method can be readily extended to the design of FSSs in other frequencies for high-power applications.
An Analysis of the Connectedness to Nature Scale Based on Item Response Theory.
Pasca, Laura; Aragonés, Juan I; Coello, María T
2017-01-01
The Connectedness to Nature Scale (CNS) is used as a measure of the subjective cognitive connection between individuals and nature. However, to date, it has not been analyzed at the item level to confirm its quality. In the present study, we conduct such an analysis based on Item Response Theory. We employed data from previous studies using the Spanish-language version of the CNS, analyzing a sample of 1008 participants. The results show that seven items presented appropriate indices of discrimination and difficulty, in addition to a good fit. The remaining six have inadequate discrimination indices and do not present a good fit. A second study with 321 participants shows that the seven-item scale has adequate levels of reliability and validity. Therefore, it would be appropriate to use a reduced version of the scale after eliminating the items that display inappropriate behavior, since they may interfere with research results on connectedness to nature.
Buatois, Simon; Retout, Sylvie; Frey, Nicolas; Ueckert, Sebastian
2017-10-01
This manuscript aims to precisely describe the natural disease progression of Parkinson's disease (PD) patients and evaluate approaches to increase the drug effect detection power. An item response theory (IRT) longitudinal model was built to describe the natural disease progression of 423 de novo PD patients followed during 48 months while taking into account the heterogeneous nature of the MDS-UPDRS. Clinical trial simulations were then used to compare drug effect detection power from IRT and sum of item scores based analysis under different analysis endpoints and drug effects. The IRT longitudinal model accurately describes the evolution of patients with and without PD medications while estimating different progression rates for the subscales. When comparing analysis methods, the IRT-based one consistently provided the highest power. IRT is a powerful tool which enables to capture the heterogeneous nature of the MDS-UPDRS.
Oscillator strengths, first-order properties, and nuclear gradients for local ADC(2).
Schütz, Martin
2015-06-07
We describe theory and implementation of oscillator strengths, orbital-relaxed first-order properties, and nuclear gradients for the local algebraic diagrammatic construction scheme through second order. The formalism is derived via time-dependent linear response theory based on a second-order unitary coupled cluster model. The implementation presented here is a modification of our previously developed algorithms for Laplace transform based local time-dependent coupled cluster linear response (CC2LR); the local approximations thus are state specific and adaptive. The symmetry of the Jacobian leads to considerable simplifications relative to the local CC2LR method; as a result, a gradient evaluation is about four times less expensive. Test calculations show that in geometry optimizations, usually very similar geometries are obtained as with the local CC2LR method (provided that a second-order method is applicable). As an exemplary application, we performed geometry optimizations on the low-lying singlet states of chlorophyllide a.
Li, Liyang; Wang, Jun; Wang, Jiafu; Ma, Hua; Du, Hongliang; Zhang, Jieqiu; Qu, Shaobo; Xu, Zhuo
2016-01-01
Based on effective medium theory and dielectric resonator theory, we propose the design of reconfigurable all-dielectric metamaterial frequency selective surfaces (FSSs) using high-permittivity ceramics. The FSS is composed of ceramic resonators with different band stop responses under front and side incidences. By mechanically tuning the orientation of the ceramic resonators, reconfigurable electromagnetic (EM) responses between two adjacent stopbands can be achieved. The two broad stopbands originate from the first two resonant modes of the ceramic resonators. As an example, a reconfigurable FSS composed of cross-shaped ceramic resonators is demonstrated. Both numerical and experimental results show that the FSS can switch between two consecutive stopbands in 3.55–4.60 GHz and 4.54–4.94 GHz. The design method can be readily extended to the design of FSSs in other frequencies for high-power applications. PMID:27052098
Using Classical Test Theory and Item Response Theory to Evaluate the LSCI
NASA Astrophysics Data System (ADS)
Schlingman, Wayne M.; Prather, E. E.; Collaboration of Astronomy Teaching Scholars CATS
2011-01-01
Analyzing the data from the recent national study using the Light and Spectroscopy Concept Inventory (LSCI), this project uses both Classical Test Theory (CTT) and Item Response Theory (IRT) to investigate the LSCI itself in order to better understand what it is actually measuring. We use Classical Test Theory to form a framework of results that can be used to evaluate the effectiveness of individual questions at measuring differences in student understanding and provide further insight into the prior results presented from this data set. In the second phase of this research, we use Item Response Theory to form a theoretical model that generates parameters accounting for a student's ability, a question's difficulty, and estimate the level of guessing. The combined results from our investigations using both CTT and IRT are used to better understand the learning that is taking place in classrooms across the country. The analysis will also allow us to evaluate the effectiveness of individual questions and determine whether the item difficulties are appropriately matched to the abilities of the students in our data set. These results may require that some questions be revised, motivating the need for further development of the LSCI. This material is based upon work supported by the National Science Foundation under Grant No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
Spillane, Nichea S.; Smith, Gregory T.
2009-01-01
We argue that ongoing criticism of existing theories, the development of alternative theories, and empirical theory tests offer the best chance for advancing American Indian research. We, therefore note our appreciation for Beals et al.'s comments. We nevertheless did disagree with many of Beals et al.'s specific claims, noting that (a) our characterization of the existing literature on reservation-dwelling American Indian drinking was accurate; (b) no argument made by Beals et al. undermines their theoretical contention that there is a relative lack of contingency between access to basic life reinforcers and sobriety on many reservations; (c) our theory was developed in a responsible manner: a reservation-tied American Indian developed the theory, which was reviewed by a reservation leadership team, a cultural consultant, and reviewers for this journal, at least one of whom consulted leaders of other reservations; and (d) our theory was based on previous interdisciplinary theory development. We encourage the development and testing of new, alternative theories. PMID:20160843
Spillane, Nichea S; Smith, Gregory T
2009-03-01
We argue that ongoing criticism of existing theories, the development of alternative theories, and empirical theory tests offer the best chance for advancing American Indian research. We, therefore note our appreciation for Beals et al.'s comments. We nevertheless did disagree with many of Beals et al.'s specific claims, noting that (a) our characterization of the existing literature on reservation-dwelling American Indian drinking was accurate; (b) no argument made by Beals et al. undermines their theoretical contention that there is a relative lack of contingency between access to basic life reinforcers and sobriety on many reservations; (c) our theory was developed in a responsible manner: a reservation-tied American Indian developed the theory, which was reviewed by a reservation leadership team, a cultural consultant, and reviewers for this journal, at least one of whom consulted leaders of other reservations; and (d) our theory was based on previous interdisciplinary theory development. We encourage the development and testing of new, alternative theories.
Urbaniok, F; Hardegger, J; Rossegger, A; Endrass, J
2006-08-01
Several authors argue that criminal behavior is generally caused by neurobiological deficits. Based on this neurobiological perspective of assumed causality, the concept of free will is questioned, and the theory of neurobiological determinism of all human behavior is put forward, thus maintaining that human beings are not responsible for their actions, and consequently the principle of guilt should be given up in criminal law. In this context the controversial debate on determinism and indeterminism, which has been held for centuries, has flared up anew, especially within the science of criminal law. When critically examining the current state of research, it becomes apparent that the results do not support the existence of a universally valid neurobiological causality of criminal behavior, nor a theory of an absolute neurobiological determinism. Neither is complete determination of all phenomena in the universe--as maintained--the logical conclusion of the principle of causality, nor is it empirically confirmed. Analyzed methodically, it cannot be falsified, and thus, as a theory which cannot be empirically tested, it represents a dogma against which plausible objections can be made. The criticism of the concept of free will, and even more so of human accountability and criminal responsibility, is not put forward in a valid way. The principle of relative determinism--the evaluation of the degree of determinism of personality factors potentially reducing criminal responsibility, which includes concrete observations and analysis of behavior--thus remains a central and cogent approach to the assessment of criminal responsibility. To sum up, the theories proposed by some authors on the complete neurobiological determinism of human behavior, and the subsequent impossibility of individual responsibility and guilt, reveal both methodical misconception and a lack of empirical foundation.
Quantum descriptors for predictive toxicology of halogenated aliphatic hydrocarbons.
Trohalaki, S; Pachter, R
2003-04-01
In order to improve Quantitative Structure-Activity Relationships (QSARs) for halogenated aliphatics (HA) and to better understand the biophysical mechanism of toxic response to these ubiquitous chemicals, we employ improved quantum-mechanical descriptors to account for HA electrophilicity. We demonstrate that, unlike the lowest unoccupied molecular orbital energy, ELUMO, which was previously used as a descriptor, the electron affinity can be systematically improved by application of higher levels of theory. We also show that employing the reciprocal of ELUMO, which is more consistent with frontier molecular orbital (FMO) theory, improves the correlations with in vitro toxicity data. We offer explanations based on FMO theory for a result from our previous work, in which the LUMO energies of HA anions correlated surprisingly well with in vitro toxicity data. Additional descriptors are also suggested and interpreted in terms of the accepted biophysical mechanism of toxic response to HAs and new QSARs are derived for various chemical categories that compose the data set employed. These alternate descriptors provide important insight and could benefit other classes of compounds where the biophysical mechanism of toxic response involves dissociative attachment.
Psychoanalysis, artistic obsession, and artistic motivation: the study of pathography.
Kemler, David S
2014-02-01
A modern assessment of Freud's conceptualization of the creative process focusing on drives, ego psychology, and object relation theory is presented. 40 artists and musicians were interviewed employing 13 open-ended questions to provoke responses historically associated with the theoretical conceptualizations of Freud and post-Freudian theory related to the creative process. Creative process was defined as internal object relations that motivate the external connection between artist and the creative work. Measured responses concerning purpose and understanding; motivation before, during, and after performance; obstacles in performance; and needs through the creative process were assessed. Cluster analysis segregated the participants into high, medium, and low agreement groups based on similarity of responses. A multivariate stepwise regression revealed four questions (enlightenment, drives, obstacles, and ought self discrepancies) accounted for 83.9% of the variance. A post hoc discriminant function analysis identified 82.5% of the population to their correct groups. The findings support Spitz's (2005) suggestion that we regard "drives, ego psychology, and object relation theory not as separate approaches but as parts of a whole with varying stresses or accents" (p. 503).
High-Fidelity Generalization Method of Cells for Inelastic Periodic Multiphase Materials
NASA Technical Reports Server (NTRS)
Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.
2002-01-01
An extension of a recently-developed linear thermoelastic theory for multiphase periodic materials is presented which admits inelastic behavior of the constituent phases. The extended theory is capable of accurately estimating both the effective inelastic response of a periodic multiphase composite and the local stress and strain fields in the individual phases. The model is presently limited to materials characterized by constituent phases that are continuous in one direction, but arbitrarily distributed within the repeating unit cell which characterizes the material's periodic microstructure. The model's analytical framework is based on the homogenization technique for periodic media, but the method of solution for the local displacement and stress fields borrows concepts previously employed by the authors in constructing the higher-order theory for functionally graded materials, in contrast with the standard finite-element solution method typically used in conjunction with the homogenization technique. The present approach produces a closed-form macroscopic constitutive equation for a periodic multiphase material valid for both uniaxial and multiaxial loading. The model's predictive accuracy in generating both the effective inelastic stress-strain response and the local stress said inelastic strain fields is demonstrated by comparison with the results of an analytical inelastic solution for the axisymmetric and axial shear response of a unidirectional composite based on the concentric cylinder model, and with finite-element results for transverse loading.
NASA Astrophysics Data System (ADS)
Silaev, M. A.
2018-06-01
We develop a theory based on the formalism of quasiclassical Green's functions to study the spin dynamics in superfluid ^3He. First, we derive kinetic equations for the spin-dependent distribution function in the bulk superfluid reproducing the results obtained earlier without quasiclassical approximation. Then, we consider spin dynamics near the surface of fully gapped ^3He-B-phase taking into account spin relaxation due to the transitions in the spectrum of localized fermionic states. The lifetimes of longitudinal and transverse spin waves are calculated taking into account the Fermi-liquid corrections which lead to a crucial modification of fermionic spectrum and spin responses.
NASA Astrophysics Data System (ADS)
Gönülateş, Emre; Kortemeyer, Gerd
2017-04-01
Homework is an important component of most physics courses. One of the functions it serves is to provide meaningful formative assessment in preparation for examinations. However, correlations between homework and examination scores tend to be low, likely due to unproductive student behavior such as copying and random guessing of answers. In this study, we attempt to model these two counterproductive learner behaviors within the framework of Item Response Theory in order to provide an ability measurement that strongly correlates with examination scores. We find that introducing additional item parameters leads to worse predictions of examination grades, while introducing additional learner traits is a more promising approach.
Thermospheric dynamics - A system theory approach
NASA Technical Reports Server (NTRS)
Codrescu, M.; Forbes, J. M.; Roble, R. G.
1990-01-01
A system theory approach to thermospheric modeling is developed, based upon a linearization method which is capable of preserving nonlinear features of a dynamical system. The method is tested using a large, nonlinear, time-varying system, namely the thermospheric general circulation model (TGCM) of the National Center for Atmospheric Research. In the linearized version an equivalent system, defined for one of the desired TGCM output variables, is characterized by a set of response functions that is constructed from corresponding quasi-steady state and unit sample response functions. The linearized version of the system runs on a personal computer and produces an approximation of the desired TGCM output field height profile at a given geographic location.
Meng, Jiao; Lv, Zhenyu; Qiao, Xinhua; Li, Xiaopeng; Li, Yazi; Zhang, Yuying; Chen, Chang
2017-04-01
Aging is tightly associated with redox events. The free radical theory of aging indicates that redox imbalance may be an important factor in the aging process. Most studies about redox and aging focused on the static status of oxidative stress levels, there has been little research investigating differential responses to redox challenge during aging. In this study, we used Caenorhabditis elegans and human fibroblasts as models to compare differential responses to oxidative stress challenge in young and old individuals. In response to paraquat stress, young individuals generated more ROS and activated signaling pathways including p-ERK, p-AKT and p-AMPKα/β. After the initial response, young individuals then promoted NRF2 translocation and induced additional antioxidant enzymes and higher expression of phase II enzymes, including SOD, CAT, GPX, HO-1, GSTP-1and others, to maintain redox homeostasis. Moreover, young individuals also demonstrated a better ability to degrade damaged proteins by up-regulating the expression of chaperones and improving proteasome activity. Based on these data, we propose a new concept "Redox-stress Response Capacity (RRC)", which suggests cells or organisms are capable of generating dynamic redox responses to activate cellular signaling and maintain cellular homeostasis. The decay of RRC is the substantive characteristic of aging, which gives a new understand of the redox theory of aging. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.
Revisiting Boundary Perturbation Theory for Inhomogeneous Transport Problems
Favorite, Jeffrey A.; Gonzalez, Esteban
2017-03-10
Adjoint-based first-order perturbation theory is applied again to boundary perturbation problems. Rahnema developed a perturbation estimate that gives an accurate first-order approximation of a flux or reaction rate within a radioactive system when the boundary is perturbed. When the response of interest is the flux or leakage current on the boundary, the Roussopoulos perturbation estimate has long been used. The Rahnema and Roussopoulos estimates differ in one term. Our paper shows that the Rahnema and Roussopoulos estimates can be derived consistently, using different responses, from a single variational functional (due to Gheorghiu and Rahnema), resolving any apparent contradiction. In analyticmore » test problems, Rahnema’s estimate and the Roussopoulos estimate produce exact first derivatives of the response of interest when appropriately applied. We also present a realistic, nonanalytic test problem.« less
Plasmonic resonances of nanoparticles from large-scale quantum mechanical simulations
NASA Astrophysics Data System (ADS)
Zhang, Xu; Xiang, Hongping; Zhang, Mingliang; Lu, Gang
2017-09-01
Plasmonic resonance of metallic nanoparticles results from coherent motion of its conduction electrons, driven by incident light. For the nanoparticles less than 10 nm in diameter, localized surface plasmonic resonances become sensitive to the quantum nature of the conduction electrons. Unfortunately, quantum mechanical simulations based on time-dependent Kohn-Sham density functional theory are computationally too expensive to tackle metal particles larger than 2 nm. Herein, we introduce the recently developed time-dependent orbital-free density functional theory (TD-OFDFT) approach which enables large-scale quantum mechanical simulations of plasmonic responses of metallic nanostructures. Using TD-OFDFT, we have performed quantum mechanical simulations to understand size-dependent plasmonic response of Na nanoparticles and plasmonic responses in Na nanoparticle dimers and trimers. An outlook of future development of the TD-OFDFT method is also presented.
Personality maturation around the world: a cross-cultural examination of social-investment theory.
Bleidorn, Wiebke; Klimstra, Theo A; Denissen, Jaap J A; Rentfrow, Peter J; Potter, Jeff; Gosling, Samuel D
2013-12-01
During early adulthood, individuals from different cultures across the world tend to become more agreeable, more conscientious, and less neurotic. Two leading theories offer different explanations for these pervasive age trends: Five-factor theory proposes that personality maturation is largely determined by genetic factors, whereas social-investment theory proposes that personality maturation in early adulthood is largely the result of normative life transitions to adult roles. In the research reported here, we conducted the first systematic cross-cultural test of these theories using data from a large Internet-based sample of young adults from 62 nations (N = 884,328). We found strong evidence for universal personality maturation from early to middle adulthood, yet there were significant cultural differences in age effects on personality traits. Consistent with social-investment theory, results showed that cultures with an earlier onset of adult-role responsibilities were marked by earlier personality maturation.
[Medical professionalism-on social responsibilities viewed from historical perspective].
Kim, Jang Han
2015-03-01
What is medical professionalism and does it matter to the patients? Medical professionals take responsibility for their judgements and the consequences that ensue. Traditionally medical professionalism is defined as a set of values, behaviors, and relationships which support the trust the public has in doctors. The public is well aware that absence of professionalism is harmful to their interests. However, the exercise of medical professionalism is endangered by the political and cultural environment. The values of professionalism have been changed throughout the medical history and the meaning of it was also changed according to social theories. Traditional medical professionalism was based on the virtue of autonomy, self-regulation and competency etc. However, in the new millenium era, the meaning of professionalism has changed under the concept of responsibility which includes the classical virtues. The meaning of professionalism nowadays is only based on the structure and conflicting theories which cannot solve all the issues surrounding professionalism in medical practice. The conditions of medical practice are critical determinants for the future of professionalism. The interaction between doctor and patient is central to the medical care, and medical professionalism has roots in almost every aspect of medical care. I argue that doctors have responsibility to act according to the values which have been determined by the medical profession, history and surrounding society. The new millennium medical professionalism which based on the responsibility could initiate a public dialogue about the role of the doctor in creating a fairer society.
Krekels, Ehj; Novakovic, A M; Vermeulen, A M; Friberg, L E; Karlsson, M O
2017-08-01
As biomarkers are lacking, multi-item questionnaire-based tools like the Positive and Negative Syndrome Scale (PANSS) are used to quantify disease severity in schizophrenia. Analyzing composite PANSS scores as continuous data discards information and violates the numerical nature of the scale. Here a longitudinal analysis based on Item Response Theory is presented using PANSS data from phase III clinical trials. Latent disease severity variables were derived from item-level data on the positive, negative, and general PANSS subscales each. On all subscales, the time course of placebo responses were best described with Weibull models, and dose-independent functions with exponential models to describe the onset of the full effect were used to describe paliperidone's effect. Placebo and drug effect were most pronounced on the positive subscale. The final model successfully describes the time course of treatment effects on the individual PANSS item-levels, on all PANSS subscale levels, and on the total score level. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.
Dodeen, Hamzeh; Al-Darmaki, Fatima
2016-12-01
The aim of this study was to determine the feasibility of generating a shorter version of the Emirati Marital Satisfaction Scale (EMSS) using item response theory (IRT)-based methodology. The EMSS is the first national scale used to provide an understanding of the family function and level of marital satisfaction within the cultural context of the United Arab Emirates. A sample of 1,049 Emirati married individuals from different ages, genders, places of residence, and monthly incomes participated in this study. The IRT was calibrated using X-Calibre 4.2 and the graded response model. The analysis was developed on the basis of a short form of the EMSS (7 items), which constitutes a promising alternative to the original scale for practitioners and researchers. This short version is reliable, valid, and it gives results very similar to the original scale. The results of this study confirmed the usefulness of IRT-based methodology for developing psychological and counseling scales. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Moving Beyond Quantum Mechanics in Search for a Generalized Theory of Superconductivity
NASA Astrophysics Data System (ADS)
Akpojotor, Godfrey; Animalu, Alexander
2012-02-01
Though there are infinite number of theories currently in the literature in the search for a generalized theory of superconductivity (SC), there may be three domineering mechanisms for the Cooper pair formation (CPF) and their emergent theories of SC. Two of these mechanisms, electron-phonon interactions and electron-electron correlations which are based on the quantum theory axiom of action-at-a distance, may be only an approximation of the third mechanism which is contact interaction of the wavepackets of the two electrons forming the Cooper pair as envisaged in hadronic mechanics to be responsible for natural bonding of elements. The application of this hydronic --type interaction to the superconducting cuprates, iron based compounds and heavy fermions leads to interesting results. It is therefore suggested that the future of the search for the theory of SC may be considered from this natural possible bonding that at short distances, the CPF is by a nonlinear, nonlocal and nonhamiltonian strong hadronic-type interactions due to deep wave-overlapping of spinning particles leading to Hulthen potential that is attractive between two electrons in singlet couplings while at large distances the CPF is by superexchange interaction which is purely a quantum mechanical affairs.
Holvoet, Nathalie; Criel, Bart
2017-01-01
Increased attention on “complexity” in health systems evaluation has resulted in many different methodological responses. Theory-driven evaluations and systems thinking are two such responses that aim for better understanding of the mechanisms underlying given outcomes. Here, we studied the implementation of a performance-based financing intervention by the Belgian Technical Cooperation in Western Uganda to illustrate a methodological strategy of combining these two approaches. We utilized a systems dynamics tool called causal loop diagramming (CLD) to generate hypotheses feeding into a theory-driven evaluation. Semi-structured interviews were conducted with 30 health workers from two districts (Kasese and Kyenjojo) and with 16 key informants. After CLD, we identified three relevant hypotheses: “success to the successful”, “growth and underinvestment”, and “supervision conundrum”. The first hypothesis leads to increasing improvements in performance, as better performance leads to more incentives, which in turn leads to better performance. The latter two hypotheses point to potential bottlenecks. Thus, the proposed methodological strategy was a useful tool for identifying hypotheses that can inform a theory-driven evaluation. The hypotheses are represented in a comprehensible way while highlighting the underlying assumptions, and are more easily falsifiable than hypotheses identified without using CLD. PMID:28869518
van der Maas, Han L J; Molenaar, Dylan; Maris, Gunter; Kievit, Rogier A; Borsboom, Denny
2011-04-01
This article analyzes latent variable models from a cognitive psychology perspective. We start by discussing work by Tuerlinckx and De Boeck (2005), who proved that a diffusion model for 2-choice response processes entails a 2-parameter logistic item response theory (IRT) model for individual differences in the response data. Following this line of reasoning, we discuss the appropriateness of IRT for measuring abilities and bipolar traits, such as pro versus contra attitudes. Surprisingly, if a diffusion model underlies the response processes, IRT models are appropriate for bipolar traits but not for ability tests. A reconsideration of the concept of ability that is appropriate for such situations leads to a new item response model for accuracy and speed based on the idea that ability has a natural zero point. The model implies fundamentally new ways to think about guessing, response speed, and person fit in IRT. We discuss the relation between this model and existing models as well as implications for psychology and psychometrics. 2011 APA, all rights reserved
Poland, Gregory A.; Kennedy, Richard B.; McKinney, Brett A.; Ovsyannikova, Inna G.; Lambert, Nathaniel D.; Jacobson, Robert M.; Oberg, Ann L.
2013-01-01
Vaccines, like drugs and medical procedures, are increasingly amenable to individualization or personalization, often based on novel data resulting from high throughput “omics” technologies. As a result of these technologies, 21st century vaccinology will increasingly see the abandonment of a “one size fits all” approach to vaccine dosing and delivery, as well as the abandonment of the empiric “isolate–inactivate–inject” paradigm for vaccine development. In this review, we discuss the immune response network theory and its application to the new field of vaccinomics and adversomics, and illustrate how vaccinomics can lead to new vaccine candidates, new understandings of how vaccines stimulate immune responses, new biomarkers for vaccine response, and facilitate the understanding of what genetic and other factors might be responsible for rare side effects due to vaccines. Perhaps most exciting will be the ability, at a systems biology level, to integrate increasingly complex high throughput data into descriptive and predictive equations for immune responses to vaccines. Herein, we discuss the above with a view toward the future of vaccinology. PMID:23755893
Thomas, Michael L
2012-03-01
There is growing evidence that psychiatric disorders maintain hierarchical associations where general and domain-specific factors play prominent roles (see D. Watson, 2005). Standard, unidimensional measurement models can fail to capture the meaningful nuances of such complex latent variable structures. The present study examined the ability of the multidimensional item response theory bifactor model (see R. D. Gibbons & D. R. Hedeker, 1992) to improve construct validity by serving as a bridge between measurement and clinical theories. Archival data consisting of 688 outpatients' psychiatric diagnoses and item-level responses to the Brief Symptom Inventory (BSI; L. R. Derogatis, 1993) were extracted from files at a university mental health clinic. The bifactor model demonstrated superior fit for the internal structure of the BSI and improved overall diagnostic accuracy in the sample (73%) compared with unidimensional (61%) and oblique simple structure (65%) models. Consistent with clinical theory, multiple sources of item variance were drawn from individual test items. Test developers and clinical researchers are encouraged to consider model-based measurement in the assessment of psychiatric distress.
Modeling the viscoplastic behavior of Inconel 718 at 1200 F
NASA Technical Reports Server (NTRS)
Abdel-Kader, M. S.; Eftis, J.; Jones, D. L.
1988-01-01
A large number of tests, including tensile, creep, fatigue, and creep-fatigue were performed to characterize the mechanical properties of Inconel 718 (a nickel based superalloy) at 1200 F, the operating temperature for turbine blades. In addition, a few attempts were made to model the behavior of Inconel 718 at 1200 F using viscoplastic theories. The Chaboche theory of viscoplasticity can model a wide variety of mechanical behavior, including monotonic, sustained, and cyclic responses of homogeneous, initially-isotropic, strain hardening (or softening) materials. It is shown how the Chaboche theory can be used to model the viscoplastic behavior of Inconel 718 at 1200 F. First, an algorithm was developed to systematically determine the material parameters of the Chaboche theory from uniaxial tensile, creep, and cyclic data. The algorithm is general and can be used in conjunction with similar high temperature materials. A sensitivity study was then performed and an optimal set of Chaboche's parameters were obtained. This study has also indicated the role of each parameter in modeling the response to different loading conditions.
Harris, Rebecca; Mosedale, Sarah; Garner, Jayne; Perkins, Elizabeth
2014-01-01
UK NHS contracts mediate the relationship between dental and medical practitioners as independent contractors, and the state which reimburses them for their services to patients. There have been successive revisions of dental and medical contracts since the 1990s alongside a change in the levels of professional dominance and accountability. Unintended consequences of the 2006 dental contract have led to plans for further reform. We set out to identify the factors which facilitate and hinder the use of contracts in this area. Previous reviews of theory have been narrative, and based on macro-theory arising from various disciplines such as economics, sociology and political science. This paper presents a systematic review and aggregative synthesis of the theories of contracting for publicly funded health care. A logic map conveys internal pathways linking competition for contracts to opportunism. We identify that whilst practitioners' responses to contract rules is a result of micro-level bargaining clarifying patients' and providers' interests, responses are also influenced by relationships with commissioners and wider personal, professional and political networks. PMID:24608120
Walczyk, Jeffrey J.; Igou, Frank P.; Dixon, Alexa P.; Tcholakian, Talar
2013-01-01
This article critically reviews techniques and theories relevant to the emerging field of “lie detection by inducing cognitive load selectively on liars.” To help these techniques benefit from past mistakes, we start with a summary of the polygraph-based Controlled Question Technique (CQT) and the major criticisms of it made by the National Research Council (2003), including that it not based on a validated theory and administration procedures have not been standardized. Lessons from the more successful Guilty Knowledge Test are also considered. The critical review that follows starts with the presentation of models and theories offering insights for cognitive lie detection that can undergird theoretically load-inducing approaches. This is followed by evaluation of specific research-based, load-inducing proposals, especially for their susceptibility to rehearsal and other countermeasures. To help organize these proposals and suggest new direction for innovation and refinement, a theoretical taxonomy is presented based on the type of cognitive load induced in examinees (intrinsic or extraneous) and how open-ended the responses to test items are. Finally, four recommendations are proffered that can help researchers and practitioners to avert the corresponding mistakes with the CQT and yield new, valid cognitive lie detection technologies. PMID:23378840
Multi-objective optimal control of vibratory energy harvesting systems
NASA Astrophysics Data System (ADS)
Scruggs, J. T.
2008-03-01
This paper presents a new approach, based on H II optimal control theory, for the maximization of power generation in energy harvesting systems. The theory determines the optimal harvested power attainable through the use of power electronics to effect linear feedback control of transducer current. In contrast to most of the prior work in this area, which has assumed harmonic response, the theory proposed here applies to stochastically-excited systems in broadband response, and can be used to harvest power simultaneously from multiple significant vibratory modes. It is also applicable to coupled networks of many transducers. The theory accounts for the impact of energy harvesting on the dynamics of the vibrating system in which the transducers are embedded. It also accounts for resistive and semiconductor dissipation in the power-electronic network interfacing the transducers with energy storage. Thus, losses in the electronics are addressed in the formulation of the optimal control law. Finally, the H II-optimal control formulation of the problem naturally allows for harvested power to be systematically balanced against other response objectives. Here, this is illustrated by showing how the harvesting objective can be maximized, subject to the constraint that the transducer voltages be maintained below that of the power-electronic bus; a condition which is required for the power-electronic control system to be fully operational. Although the theory is applicable across a broad range of applications, it is presented in the context of a piezoelectric bimorph example.
Compression induced phase transition of nematic brush: A mean-field theory study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tang, Jiuzhou; Zhang, Xinghua, E-mail: zhangxh@bjtu.edu.cn; Yan, Dadong, E-mail: yandd@bnu.edu.cn
2015-11-28
Responsive behavior of polymer brush to the external compression is one of the most important characters for its application. For the flexible polymer brush, in the case of low grafting density, which is widely studied by the Gaussian chain model based theory, the compression leads to a uniform deformation of the chain. However, in the case of high grafting density, the brush becomes anisotropic and the nematic phase will be formed. The normal compression tends to destroy the nematic order, which leads to a complex responsive behaviors. Under weak compression, chains in the nematic brush are buckled, and the bendingmore » energy and Onsager interaction give rise to the elasticity. Under deep compression, the responsive behaviors of the nematic polymer brush depend on the chain rigidity. For the compressed rigid polymer brush, the chains incline to re-orientate randomly to maximize the orientational entropy and its nematic order is destroyed. For the compressed flexible polymer brush, the chains incline to fold back to keep the nematic order. A buckling-folding transition takes place during the compressing process. For the compressed semiflexible brush, the chains are collectively tilted to a certain direction, which leads to the breaking of the rotational symmetry in the lateral plane. These responsive behaviors of nematic brush relate to the properties of highly frustrated worm-like chain, which is hard to be studied by the traditional self-consistent field theory due to the difficulty to solve the modified diffusion equation. To overcome this difficulty, a single chain in mean-field theory incorporating Monte Carlo simulation and mean-field theory for the worm-like chain model is developed in present work. This method shows high performance for entire region of chain rigidity in the confined condition.« less
Consumer psychology: categorization, inferences, affect, and persuasion.
Loken, Barbara
2006-01-01
This chapter reviews research on consumer psychology with emphasis on the topics of categorization, inferences, affect, and persuasion. The chapter reviews theory-based empirical research during the period 1994-2004. Research on categorization includes empirical research on brand categories, goals as organizing frameworks and motivational bases for judgments, and self-based processing. Research on inferences includes numerous types of inferences that are cognitively and/or experienced based. Research on affect includes the effects of mood on processing and cognitive and noncognitive bases for attitudes and intentions. Research on persuasion focuses heavily on the moderating role of elaboration and dual-process models, and includes research on attitude strength responses, advertising responses, and negative versus positive evaluative dimensions.
ERIC Educational Resources Information Center
Hussein, Mohamed Habashy
2010-01-01
The present study examined the psychometric properties of the Arabic version of Children's Self-report Social Skills Scale (CS[superscript 4]) using a generalized partial credit model (GPCM). Data from 722 primary school children (401 boys and 321 girls) responses, in Egypt, were analyzed using GPCM. The results indicated that the 21 items are…
ERIC Educational Resources Information Center
Li, Yanmei; Li, Shuhong; Wang, Lin
2010-01-01
Many standardized educational tests include groups of items based on a common stimulus, known as "testlets". Standard unidimensional item response theory (IRT) models are commonly used to model examinees' responses to testlet items. However, it is known that local dependence among testlet items can lead to biased item parameter estimates…
Social cognitive theory, metacognition, and simulation learning in nursing education.
Burke, Helen; Mancuso, Lorraine
2012-10-01
Simulation learning encompasses simple, introductory scenarios requiring response to patients' needs during basic hygienic care and during situations demanding complex decision making. Simulation integrates principles of social cognitive theory (SCT) into an interactive approach to learning that encompasses the core principles of intentionality, forethought, self-reactiveness, and self-reflectiveness. Effective simulation requires an environment conducive to learning and introduces activities that foster symbolic coding operations and mastery of new skills; debriefing builds self-efficacy and supports self-regulation of behavior. Tailoring the level of difficulty to students' mastery level supports successful outcomes and motivation to set higher standards. Mindful selection of simulation complexity and structure matches course learning objectives and supports progressive development of metacognition. Theory-based facilitation of simulated learning optimizes efficacy of this learning method to foster maturation of cognitive processes of SCT, metacognition, and self-directedness. Examples of metacognition that are supported through mindful, theory-based implementation of simulation learning are provided. Copyright 2012, SLACK Incorporated.
Analyzing force concept inventory with item response theory
NASA Astrophysics Data System (ADS)
Wang, Jing; Bao, Lei
2010-10-01
Item response theory is a popular assessment method used in education. It rests on the assumption of a probability framework that relates students' innate ability and their performance on test questions. Item response theory transforms students' raw test scores into a scaled proficiency score, which can be used to compare results obtained with different test questions. The scaled score also addresses the issues of ceiling effects and guessing, which commonly exist in quantitative assessment. We used item response theory to analyze the force concept inventory (FCI). Our results show that item response theory can be useful for analyzing physics concept surveys such as the FCI and produces results about the individual questions and student performance that are beyond the capability of classical statistics. The theory yields detailed measurement parameters regarding the difficulty, discrimination features, and probability of correct guess for each of the FCI questions.
An English Vocabulary Learning System Based on Fuzzy Theory and Memory Cycle
NASA Astrophysics Data System (ADS)
Wang, Tzone I.; Chiu, Ti Kai; Huang, Liang Jun; Fu, Ru Xuan; Hsieh, Tung-Cheng
This paper proposes an English Vocabulary Learning System based on the Fuzzy Theory and the Memory Cycle Theory to help a learner to memorize vocabularies easily. By using fuzzy inferences and personal memory cycles, it is possible to find an article that best suits a learner. After reading an article, a quiz is provided for the learner to improve his/her memory of the vocabulary in the article. Early researches use just explicit response (ex. quiz exam) to update memory cycles of newly learned vocabulary; apart from that approach, this paper proposes a methodology that also modify implicitly the memory cycles of learned word. By intensive reading of articles recommended by our approach, a learner learns new words quickly and reviews learned words implicitly as well, and by which the vocabulary ability of the learner improves efficiently.
Microdosimetry and Katz's track structure theory. I. One-hit detectors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zaider, M.
1990-10-01
A microdosimetric treatment of the response of one-hit detectors to radiation is formulated and compared with the model proposed by R. Katz, S. C. Sharma, and M. Homayoonfar within the framework of their track-structure theory. It is shown that radial dose distributions (on which the track structure theory is based) are generally poor substitutes for the exact microdosimetric distributions except when (a) the target is much larger than the radial extent of the track or (b) the effective specific energy in the target (alpha z) is negligibly small. Since neither one of these conditions is generally satisfied, it is suggestedmore » that a meaningful search for one-hit detectors be based on a microdosimetric description of the stochastics of energy deposition. An analysis of the phi x-174 bacteriophage inactivation data is presented.« less
Stepwise Analysis of Differential Item Functioning Based on Multiple-Group Partial Credit Model.
ERIC Educational Resources Information Center
Muraki, Eiji
1999-01-01
Extended an Item Response Theory (IRT) method for detection of differential item functioning to the partial credit model and applied the method to simulated data using a stepwise procedure. Then applied the stepwise DIF analysis based on the multiple-group partial credit model to writing trend data from the National Assessment of Educational…
Detecting DIF in Polytomous Items Using MACS, IRT and Ordinal Logistic Regression
ERIC Educational Resources Information Center
Elosua, Paula; Wells, Craig
2013-01-01
The purpose of the present study was to compare the Type I error rate and power of two model-based procedures, the mean and covariance structure model (MACS) and the item response theory (IRT), and an observed-score based procedure, ordinal logistic regression, for detecting differential item functioning (DIF) in polytomous items. A simulation…
ERIC Educational Resources Information Center
Boyd, Aimee M.; Dodd, Barbara; Fitzpatrick, Steven
2013-01-01
This study compared several exposure control procedures for CAT systems based on the three-parameter logistic testlet response theory model (Wang, Bradlow, & Wainer, 2002) and Masters' (1982) partial credit model when applied to a pool consisting entirely of testlets. The exposure control procedures studied were the modified within 0.10 logits…
ERIC Educational Resources Information Center
Dietrich, Timo; Rundle-Thiele, Sharyn; Leo, Cheryl; Connor, Jason
2015-01-01
Background: According to commercial marketing theory, a market orientation leads to improved performance. Drawing on the social marketing principles of segmentation and audience research, the current study seeks to identify segments to examine responses to a school-based alcohol social marketing program. Methods: A sample of 371 year 10 students…
ERIC Educational Resources Information Center
Herring, Mary Corwin
2004-01-01
In response to societal shifts, K-12 teachers are struggling to design effective learning environments. The advent of increased access to world-linking technology has extended the use of distance education to enrich and expand the learning landscape for students. A number of individuals have suggested that a body of learning theory,…
A Critique and Response to Multicultural Visions of Globalization
ERIC Educational Resources Information Center
Sriraman, Bharath; Adrian, Harry
2008-01-01
The paper by White in this issue of Interchange contains an interesting model for a global educational perspective based on the writings of Aurobindo and Pierre Teilhard de Chardin. White proposes a foundation for this new perspective based on the synthesis of Aurobindo's and de Chardin's theories of global, social, and conscious evolution. In our…
ERIC Educational Resources Information Center
Clark, Joseph Warren
2012-01-01
In turbulent business environments, change is rapid, continuous, and unpredictable. Turbulence undermines those adaptive problem solving methods that generate solutions by extrapolating from what worked (or did not work) in the past. To cope with this challenge, organizations utilize trial-based problem solving (TBPS) approaches in which they…
Toward a theory of leadership and state building
Myerson, Roger B.
2011-01-01
We present a theory of the state based on political leadership and reputational equilibria. A political leader first needs a reputation for reliably rewarding loyal supporters. Reputational expectations between political leaders and their supporters become the fundamental political laws on which the enforcement of all other constitutional laws may be based. Successful democratic development requires a plentiful supply of leaders who have good reputations for using public funds responsibly to serve the public at large and not just giving jobs to their active supporters. It is argued that decentralized democracy may be the best way to improve the chances for successful democracy. PMID:22198758
Meynen, Gerben
2012-01-01
Within the context of an ethical theory of responsibility, Susan Wolf has argued that people can only be considered fully responsible for their actions when they are sane. In this paper I explore the possibility of applying her ethical account of sanity and responsibility to forensic assessments of criminal responsibility. I argue that after some substantial revisions her account can be helpful in order to arrive at an ethics-based conceptual framework for forensic psychiatric assessments within the context of an insanity defense. Copyright © 2012 Elsevier Ltd. All rights reserved.
Betrus, P A; Elmore, S K; Woods, N F; Hamilton, P A
1995-01-01
As Western society increases in complexity and becomes more reliant on technology, women who thrive as integrators in interactional modes will face new dilemmas. Many women will view these changes as challenges, but for many other women, who view these changes as threats, the response will be depression. We lay a foundation to an understanding of depression in women, evaluating the current concept of depression and pointing out its limitations. We then review the traditional theories of women's increased vulnerability to depressive disorders, which have failed to explain adequately this phenomenon. A more recent theory of women's depression, based on the self-in-relation theory of women's development, is offered as an alternative.
Toward a social justice theory of demographic transition: lessons from India's Kerala State.
Ratcliffe, J W
1983-06-01
Recent research evidence, which suggests that observed demographic trends and patterns are largely consequences of broad structural changes in society, has raised serious doubts about the validity of traditional demographic theory and the framework for action it has generated. This theoretical essay 1st recasts classical demographic transition theory in general systems terms in order to make it consistent with the evidence and to place the processes of fertility and mortality in a larger social context. The demographic transition experience of Kerala State, India is then recounted to provide a concrete example of the demographic response in society to structural reforms based primarily on equity considerations.
NASA Astrophysics Data System (ADS)
Katul, G. G.; Palmroth, S.; Manzoni, S.; Oren, R.
2012-12-01
Global climate models predict decreases in leaf stomatal conductance (gs) and transpiration due to increases in atmospheric CO2. The consequences of these reductions are increases in soil moisture availability and continental scale run-off at decadal time-scales. Thus, a theory explaining the differential sensitivity of stomata to changing atmospheric CO2 and other environmental conditions such as soil moisture at the ecosystem scale must be identified. Here, these responses are investigated using an optimality theory applied to stomatal conductance. An analytical model for gs is first proposed based on (a) Fickian mass transfer of CO2 and H2O through stomata; (b) a biochemical photosynthesis model that relates intercellular CO2 to net photosynthesis; and (c) a stomatal model based on optimization for maximizing carbon gains when water losses represent a cost. The optimization theory produced three gas exchange responses that are consistent with observations across a wide-range of species: (1) the sensitivity of gs to vapour pressure deficit (D) is similar to that obtained from a previous synthesis of more than 40 species, (2) the theory is consistent with the onset of an apparent 'feed-forward' mechanism in gs, and (3) the emergent non-linear relationship between the ratio of intercellular to atmospheric CO2 (ci/ca) and D agrees with the results available on this response. A simplified version of this leaf-scale approach recovers the linear relationship between stomatal conductance and leaf-photosynthesis employed in numerous climate models that currently use a variant on the 'Ball-Berry' or the 'Leuning' approaches provided the marginal water use efficiency increases linearly with atmospheric CO2. The model is then up-scaled to the canopy-level using novel theories about the structure of turbulence inside vegetation. This up-scaling proved to be effective in resolving the complex (and two-way) interactions between leaves and their immediate micro-climate. Extensions of this optimality approach to drought and salt-stressed cases are briefly presented.
Psychometric Properties of IRT Proficiency Estimates
ERIC Educational Resources Information Center
Kolen, Michael J.; Tong, Ye
2010-01-01
Psychometric properties of item response theory proficiency estimates are considered in this paper. Proficiency estimators based on summed scores and pattern scores include non-Bayes maximum likelihood and test characteristic curve estimators and Bayesian estimators. The psychometric properties investigated include reliability, conditional…
Somatic experiencing: using interoception and proprioception as core elements of trauma therapy
Payne, Peter; Levine, Peter A.; Crane-Godreau, Mardi A.
2015-01-01
Here we present a theory of human trauma and chronic stress, based on the practice of Somatic Experiencing® (SE), a form of trauma therapy that emphasizes guiding the client's attention to interoceptive, kinesthetic, and proprioceptive experience. SE™ claims that this style of inner attention, in addition to the use of kinesthetic and interoceptive imagery, can lead to the resolution of symptoms resulting from chronic and traumatic stress. This is accomplished through the completion of thwarted, biologically based, self-protective and defensive responses, and the discharge and regulation of excess autonomic arousal. We present this theory through a composite case study of SE treatment; based on this example, we offer a possible neurophysiological rationale for the mechanisms involved, including a theory of trauma and chronic stress as a functional dysregulation of the complex dynamical system formed by the subcortical autonomic, limbic, motor and arousal systems, which we term the core response network (CRN). We demonstrate how the methods of SE help restore functionality to the CRN, and we emphasize the importance of taking into account the instinctive, bodily based protective reactions when dealing with stress and trauma, as well as the effectiveness of using attention to interoceptive, proprioceptive and kinesthetic sensation as a therapeutic tool. Finally, we point out that SE and similar somatic approaches offer a supplement to cognitive and exposure therapies, and that mechanisms similar to those discussed in the paper may also be involved in the benefits of meditation and other somatic practices. PMID:25699005
Organizational Theory and Student Cheating: Explanation, Responses, and Strategies
ERIC Educational Resources Information Center
Gallant, Tricia Bertram; Drinan, Patrick
2006-01-01
Studies have described and analyzed the problem of student cheating as well as institutional responses to the problem. However, organizational theory has been neglected. Viewing student cheating and institutional responses through the lens of organizational theory can inform strategy and instill fresh approaches to the management of the problem.
A Multidimensional Ideal Point Item Response Theory Model for Binary Data.
Maydeu-Olivares, Albert; Hernández, Adolfo; McDonald, Roderick P
2006-12-01
We introduce a multidimensional item response theory (IRT) model for binary data based on a proximity response mechanism. Under the model, a respondent at the mode of the item response function (IRF) endorses the item with probability one. The mode of the IRF is the ideal point, or in the multidimensional case, an ideal hyperplane. The model yields closed form expressions for the cell probabilities. We estimate and test the goodness of fit of the model using only information contained in the univariate and bivariate moments of the data. Also, we pit the new model against the multidimensional normal ogive model estimated using NOHARM in four applications involving (a) attitudes toward censorship, (b) satisfaction with life, (c) attitudes of morality and equality, and (d) political efficacy. The normal PDF model is not invariant to simple operations such as reverse scoring. Thus, when there is no natural category to be modeled, as in many personality applications, it should be fit separately with and without reverse scoring for comparisons.
A theoretical framework for measuring knowledge in screening decision aid trials.
Smith, Sian K; Barratt, Alexandra; Trevena, Lyndal; Simpson, Judy M; Jansen, Jesse; McCaffery, Kirsten J
2012-11-01
To describe a theoretical framework for assessing knowledge about the possible outcomes of participating in bowel cancer screening for the faecal occult blood test. The content of the knowledge measure was based on the UK General Medical Council's screening guidelines and a theory-based approach to assessing gist knowledge (Fuzzy Trace Theory). It comprised conceptual and numeric questions to assess knowledge of the underlying construct (e.g. false positive concept) and the approximate numbers affected (e.g. likelihood of a false positive). The measure was used in a randomised controlled trial involving 530 adults with low education, to compare the impact of a bowel screening decision aid with a screening information booklet developed for the Australian Government National Bowel Cancer Screening Program. The numeric knowledge scale was particularly responsive to the effects of the decision aid; at follow-up decision aid participants' numeric knowledge was significantly greater than the controls (P<0.001). This contrasts with the conceptual knowledge scale which improved significantly in both groups from baseline to follow-up (P<0.001). Our theory-based knowledge measure was responsive to change in conceptual knowledge and to the effect on numeric knowledge of a decision aid. This theoretical framework has the potential to guide the development of knowledge measures in other screening settings. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Mumbardó-Adam, C; Guàrdia-Olmos, J; Giné, C; Raley, S K; Shogren, K A
2018-04-01
A new measure of self-determination, the Self-Determination Inventory: Student Report (Spanish version), has recently been adapted and empirically validated in Spanish language. As it is the first instrument intended to measure self-determination in youth with and without disabilities, there is a need to further explore and strengthen its psychometric analysis based on item response patterns. Through item response theory approach, this study examined item observed distributions across the essential characteristics of self-determination. The results demonstrated satisfactory to excellent item functioning patterns across characteristics, particularly within agentic action domains. Increased variability across items was also found within action-control beliefs dimensions, specifically within the self-realisation subdomain. These findings further support the instrument's psychometric properties and outline future research directions. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.
Generalized continuum modeling of scale-dependent crystalline plasticity
NASA Astrophysics Data System (ADS)
Mayeur, Jason R.
The use of metallic material systems (e.g. pure metals, alloys, metal matrix composites) in a wide range of engineering applications from medical devices to electronic components to automobiles continues to motivate the development of improved constitutive models to meet increased performance demands while minimizing cost. Emerging technologies often incorporate materials in which the dominant microstructural features have characteristic dimensions reaching into the submicron and nanometer regime. Metals comprised of such fine microstructures often exhibit unique and size-dependent mechanical response, and classical approaches to constitutive model development at engineering (continuum) scales, being local in nature, are inadequate for describing such behavior. Therefore, traditional modeling frameworks must be augmented and/or reformulated to account for such phenomena. Crystal plasticity constitutive models have proven quite capable of capturing first-order microstructural effects such as grain orientation (elastic/plastic anisotropy), grain morphology, phase distribution, etc. on the deformation behavior of both single and polycrystals, yet suffer from the same limitations as other local continuum theories with regard to capturing scale-dependent mechanical response. This research is focused on the development, numerical implementation, and application of a generalized (nonlocal) theory of single crystal plasticity capable of describing the scale-dependent mechanical response of both single and polycrystalline metals that arises as a result of heterogeneous deformation. This research developed a dislocation-based theory of micropolar single crystal plasticity. The majority of nonlocal crystal plasticity theories are predicated on the connection between gradients of slip and geometrically necessary dislocations. Due to the diversity of existing nonlocal crystal plasticity theories, a review, summary, and comparison of representative model classes is presented in Chapter 2 from a unified dislocation-based perspective. The discussion of the continuum crystal plasticity theories is prefaced by a brief review of discrete dislocation plasticity, which facilitates the comparison of certain model aspects and also serves as a reference for latter segments of the research which make connection to this constitutive description. Chapter 2 has utility not only as a literature review, but also as a synthesis and analysis of competing and alternative nonlocal crystal plasticity modeling strategies from a common viewpoint. The micropolar theory of single crystal plasticity is presented in Chapter 3. Two different types of flow criteria are considered - the so-called single and multicriterion theories, and several variations of the dislocation-based strength models appropriate for each theory are presented and discussed. The numerical implementation of the two-dimensional version of the constitutive theory is given in Chapter 4. A user element subroutine for the implicit commercial finite element code Abaqus/Standard is developed and validated through the solution of initial-boundary value problems with closed-form solutions. Convergent behavior of the subroutine is also demonstrated for an initial-boundary value problem exhibiting strain localization. In Chapter 5, the models are employed to solve several standard initial-boundary value problems for heterogeneously deforming single crystals including simple shearing of a semi-infinite constrained thin film, pure bending of thin films, and simple shearing of a metal matrix composite with elastic inclusions. The simulation results are compared to those obtained from the solution of equivalent boundary value problems using discrete dislocation dynamics and alternative generalized crystal plasticity theories. Comparison and calibration with respect to the former provides guidance in the specification of non-traditional material parameters that arise in the model formulation and demonstrates its effectiveness at capturing the heterogeneous deformation fields and size-dependent mechanical behavior predicted by a finer scale constitutive description. Finally, in Chapter 6, the models are applied to simulate the deformation behavior of small polycrystalline ensembles. Several grain boundary constitutive descriptions are explored and the response characteristics are analyzed with respect to experimental observations as well as results obtained from discrete dislocation dynamics and alternative nonlocal crystal plasticity theories. Particular attention is focused on how the various grain boundary descriptions serve to either locally concentrate or diffuse deformation heterogeneity as a function of grain size.
Personalized E-Learning System Using Item Response Theory
ERIC Educational Resources Information Center
Chih-Ming, Chen; Lee, Hahn-Ming; Chen, Ya-Hui
2005-01-01
Personalized service is important on the Internet, especially in Web-based learning. Generally, most personalized systems consider learner preferences, interests, and browsing behaviors in providing personalized services. However, learner ability usually is neglected as an important factor in implementing personalization mechanisms. Besides, too…
Soil-mediated effects of global change on plant communities depend on plant growth form
USDA-ARS?s Scientific Manuscript database
(1) Understanding why species respond to climate change is critical for forecasting invasions, diversity, and productivity of communities. Although researchers often predict species’ distributions and productivity based on direct physiological responses to environments, theory suggests that striking...
2017-12-01
civil society, focusing on civil society groups that may be responsible for promoting stereotypes. The thesis suggests that Orientalism and efforts...reach wider audiences to effect change based on intergroup contact theory, which promotes interaction among different groups . Second, advocacy...the reasons behind American media’s promotion of prejudice in civil society, focusing on civil society groups that may be responsible for promoting
ERIC Educational Resources Information Center
Roberts, James S.; Donoghue, John R.; Laughlin, James E.
The generalized graded unfolding model (J. Roberts, J. Donoghue, and J. Laughlin, 1998, 1999) is an item response theory model designed to unfold polytomous responses. The model is based on a proximity relation that postulates higher levels of expected agreement with a given statement to the extent that a respondent is located close to the…
ERIC Educational Resources Information Center
Eddy, Peter A.; And Others
A study was undertaken in order to provide current data and comprehensive information about Chinese language instruction in United States higher education. This report is based on the responses to a survey in 1979. In addition to the discussion of the survey responses, an examination of changes that have taken place since a previous report in 1969…
Adaptation to sensory-motor reflex perturbations is blind to the source of errors.
Hudson, Todd E; Landy, Michael S
2012-01-06
In the study of visual-motor control, perhaps the most familiar findings involve adaptation to externally imposed movement errors. Theories of visual-motor adaptation based on optimal information processing suppose that the nervous system identifies the sources of errors to effect the most efficient adaptive response. We report two experiments using a novel perturbation based on stimulating a visually induced reflex in the reaching arm. Unlike adaptation to an external force, our method induces a perturbing reflex within the motor system itself, i.e., perturbing forces are self-generated. This novel method allows a test of the theory that error source information is used to generate an optimal adaptive response. If the self-generated source of the visually induced reflex perturbation is identified, the optimal response will be via reflex gain control. If the source is not identified, a compensatory force should be generated to counteract the reflex. Gain control is the optimal response to reflex perturbation, both because energy cost and movement errors are minimized. Energy is conserved because neither reflex-induced nor compensatory forces are generated. Precision is maximized because endpoint variance is proportional to force production. We find evidence against source-identified adaptation in both experiments, suggesting that sensory-motor information processing is not always optimal.
Gelhorn, Heather; Hartman, Christie; Sakai, Joseph; Stallings, Michael; Young, Susan; Rhee, Soo Hyun; Corley, Robin; Hewitt, John; Hopfer, Christian; Crowley, Thomas
2008-11-01
Item response theory analyses were used to examine alcohol abuse and dependence symptoms and diagnoses in adolescents. Previous research suggests that the DSM-IV alcohol use disorder (AUD) symptoms in adolescents may be characterized by a single dimension. The present study extends prior research with a larger and more comprehensive sample and an examination of an alternative diagnostic algorithm for AUDs. Approximately 5,587 adolescents between the ages of 12 and 18 years from adjudicated, clinical, and community samples were administered structured clinical interviews. Analyses were conducted to examine the severity of alcohol abuse and dependence symptoms and the severity of alcohol use problems (AUDs) within the diagnostic categories created by the DSM-IV. Although the DSM-IV diagnostic categories differ in severity of AUDs, there is substantial overlap and inconsistency in AUD severity of persons across these categories. Item Response Theory-based AUD severity estimates suggest that many persons diagnosed with abuse have AUD severity greater than persons with dependence. Similarly, many persons who endorse some symptoms but do not qualify for a diagnosis (i.e., diagnostic orphans) have more severe AUDs than persons with an abuse diagnosis. Additionally, two dependence items, "tolerance" and "larger/longer," show differences in severity between samples. The distinction between DSM-IV abuse and dependence based on severity can be improved using an alternative diagnostic algorithm that considers all of the alcohol abuse and dependence symptoms conjointly.
Computerized Adaptive Test (CAT) Applications and Item Response Theory Models for Polytomous Items
ERIC Educational Resources Information Center
Aybek, Eren Can; Demirtasli, R. Nukhet
2017-01-01
This article aims to provide a theoretical framework for computerized adaptive tests (CAT) and item response theory models for polytomous items. Besides that, it aims to introduce the simulation and live CAT software to the related researchers. Computerized adaptive test algorithm, assumptions of item response theory models, nominal response…
On Multidimensional Item Response Theory: A Coordinate-Free Approach. Research Report. ETS RR-07-30
ERIC Educational Resources Information Center
Antal, Tamás
2007-01-01
A coordinate-free definition of complex-structure multidimensional item response theory (MIRT) for dichotomously scored items is presented. The point of view taken emphasizes the possibilities and subtleties of understanding MIRT as a multidimensional extension of the classical unidimensional item response theory models. The main theorem of the…
ERIC Educational Resources Information Center
Hospers, J. Mirjam Boeschen; Smits, Niels; Smits, Cas; Stam, Mariska; Terwee, Caroline B.; Kramer, Sophia E.
2016-01-01
Purpose: We reevaluated the psychometric properties of the Amsterdam Inventory for Auditory Disability and Handicap (AIADH; Kramer, Kapteyn, Festen, & Tobi, 1995) using item response theory. Item response theory describes item functioning along an ability continuum. Method: Cross-sectional data from 2,352 adults with and without hearing…
Slob, Wout
2017-04-01
A general theory on effect size for continuous data predicts a relationship between maximum response and within-group variation of biological parameters, which is empirically confirmed by results from dose-response analyses of 27 different biological parameters. The theory shows how effect sizes observed in distinct biological parameters can be compared and provides a basis for a generic definition of small, intermediate and large effects. While the theory is useful for experimental science in general, it has specific consequences for risk assessment: it solves the current debate on the appropriate metric for the Benchmark response in continuous data. The theory shows that scaling the BMR expressed as a percent change in means to the maximum response (in the way specified) automatically takes "natural variability" into account. Thus, the theory supports the underlying rationale of the BMR 1 SD. For various reasons, it is, however, recommended to use a BMR in terms of a percent change that is scaled to maximum response and/or within group variation (averaged over studies), as a single harmonized approach.
Dual coding theory, word abstractness, and emotion: a critical review of Kousta et al. (2011).
Paivio, Allan
2013-02-01
Kousta, Vigliocco, Del Campo, Vinson, and Andrews (2011) questioned the adequacy of dual coding theory and the context availability model as explanations of representational and processing differences between concrete and abstract words. They proposed an alternative approach that focuses on the role of emotional content in the processing of abstract concepts. Their dual coding critique is, however, based on impoverished and, in some respects, incorrect interpretations of the theory and its implications. This response corrects those gaps and misinterpretations and summarizes research findings that show predicted variations in the effects of dual coding variables in different tasks and contexts. Especially emphasized is an empirically supported dual coding theory of emotion that goes beyond the Kousta et al. emphasis on emotion in abstract semantics. 2013 APA, all rights reserved
Emotional intervention strategies for dementia-related behavior: a theory synthesis.
Yao, Lan; Algase, Donna
2008-04-01
Behavioral disturbances of elders with dementia are prevalent. Yet the science guiding development and testing of effective intervention strategies is limited by rudimentary and often-conflicting theories. Using a theory-synthesis approach conducted within the perspective of the need-driven dementia-compromised behavior model, this article presents the locomoting responses to environment in elders with dementia (LRE-EWD) model. This new model, based on empirical and theoretical evidence, integrates the role of emotion with that of cognition in explicating a person-environment dynamic supporting wandering and other dementia-related disturbances. Included is evidence of the theory's testability and elaboration of its implications. The LRE-EWD model resolves conflicting views and evidence from current research on environmental interventions for behavior disturbances and opens new avenues to advance this field of study and practice.
Fulmer, Ingrid Smithey; Shaw, Jason D
2018-06-07
Compensation research has focused traditionally on how pay design characteristics (e.g., pay level, individual or group incentives) relate to average employee outcomes and, in toto, on how these outcomes affect organizational performance. Recently, scholars have begun to pay more attention to how individuals vary in the strength of their reactions to pay. Empirical research in several disciplines examines how the interplay of pay systems and person-based characteristics (psychological individual differences, demographics, and relative performance or position in a group) relate to important work-related outcomes. We develop a compensation-activation theory that frames compensation design characteristics as workplace "situations" providing cues that activate individuals' corresponding fundamental social motives made salient due to chronic or transient person-based characteristics. Where activation occurs, stronger-than-average responses to the compensation "situation" are expected. Using the theory as a lens, we synthesize and reinterpret existing research on person-based reactions to pay characteristics, including sorting, incentive/motivational effects, and effects on collective pay system reactions and unit/organizational outcomes. We conclude with a research agenda aimed at refining compensation-activation theory and advancing the study of compensation as it affects individual and organizational outcomes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Vispoel, Walter P; Morris, Carrie A; Kilinc, Murat
2018-01-01
We applied a new approach to Generalizability theory (G-theory) involving parallel splits and repeated measures to evaluate common uses of the Paulhus Deception Scales based on polytomous and four types of dichotomous scoring. G-theory indices of reliability and validity accounting for specific-factor, transient, and random-response measurement error supported use of polytomous over dichotomous scores as contamination checks; as control, explanatory, and outcome variables; as aspects of construct validation; and as indexes of environmental effects on socially desirable responding. Polytomous scoring also provided results for flagging faking as dependable as those when using dichotomous scoring methods. These findings argue strongly against the nearly exclusive use of dichotomous scoring for the Paulhus Deception Scales in practice and underscore the value of G-theory in demonstrating this. We provide guidelines for applying our G-theory techniques to other objectively scored clinical assessments, for using G-theory to estimate how changes to a measure might improve reliability, and for obtaining software to conduct G-theory analyses free of charge.
The Value of Item Response Theory in Clinical Assessment: A Review
ERIC Educational Resources Information Center
Thomas, Michael L.
2011-01-01
Item response theory (IRT) and related latent variable models represent modern psychometric theory, the successor to classical test theory in psychological assessment. Although IRT has become prevalent in the measurement of ability and achievement, its contributions to clinical domains have been less extensive. Applications of IRT to clinical…
The Systematic Development of an Internet-Based Smoking Cessation Intervention for Adults.
Dalum, Peter; Brandt, Caroline Lyng; Skov-Ettrup, Lise; Tolstrup, Janne; Kok, Gerjo
2016-07-01
Objectives The objective of this project was to determine whether intervention mapping is a suitable strategy for developing an Internet- and text message-based smoking cessation intervention. Method We used the Intervention Mapping framework for planning health promotion programs. After a needs assessment, we identified important changeable determinants of cessation behavior, specified objectives for the intervention, selected theoretical methods for meeting our objectives, and operationalized change methods into practical intervention strategies. Results We found that "social cognitive theory," the "transtheoretical model/stages of change," "self-regulation theory," and "appreciative inquiry" were relevant theories for smoking cessation interventions. From these theories, we selected modeling/behavioral journalism, feedback, planning coping responses/if-then statements, gain frame/positive imaging, consciousness-raising, helping relationships, stimulus control, and goal-setting as suitable methods for an Internet- and text-based adult smoking cessation program. Furthermore, we identified computer tailoring as a useful strategy for adapting the intervention to individual users. Conclusion The Intervention Mapping method, with a clear link between behavioral goals, theoretical methods, and practical strategies and materials, proved useful for systematic development of a digital smoking cessation intervention for adults. © 2016 Society for Public Health Education.
Chilisa, Bagele; Mohiemang, Irene; Mpeta, Kolentino Nyamadzapasi; Malinga, Tumane; Ntshwarang, Poloko; Koyabe, Bramwell Walela; Heeren, G Anita
2016-01-01
Culture and tradition influences behaviour. Multiple partner and concurrent relationships are made responsible for the increase of HIV infection in Sub-Saharan Africa. A contextualized "Theory of Planned Behaviour" was used to identify predictors of intention to practice monogamy. A mixed method design using qualitative data from focus groups, stories and a survey were analyzed for quantitative data. The qualitative data added to the behavioural beliefs a socio-cultural belief domain as well as attitudes, subjective norms, and perceived behavioural control predicted the intention to practice monogamy. The adolescents showed a tendency towards having more than one sexual partner. The normative beliefs and the socio cultural beliefs also predicted intentions while hedonistic belief and partner reaction did not. In contextualizing theory-based interventions, it is important to draw from stories and the langauage that circulate in a community about a given behaviour. More studies are needed on ways to combine qualitative approaches with quantitative approaches to inform the development of theory based culturally appropriate and context specific intervention strategies to reduce the risk of HIV.
Chilisa, Bagele; Mohiemang, Irene; Mpeta, Kolentino Nyamadzapasi; Malinga, Tumane; Ntshwarang, Poloko; Koyabe, Bramwell Walela; Heeren, G. Anita
2016-01-01
Culture and tradition influences behaviour. Multiple partner and concurrent relationships are made responsible for the increase of HIV infection in Sub-Saharan Africa. A contextualized “Theory of Planned Behaviour” was used to identify predictors of intention to practice monogamy. A mixed method design using qualitative data from focus groups, stories and a survey were analyzed for quantitative data. The qualitative data added to the behavioural beliefs a socio-cultural belief domain as well as attitudes, subjective norms, and perceived behavioural control predicted the intention to practice monogamy. The adolescents showed a tendency towards having more than one sexual partner. The normative beliefs and the socio cultural beliefs also predicted intentions while hedonistic belief and partner reaction did not. In contextualizing theory-based interventions, it is important to draw from stories and the langauage that circulate in a community about a given behaviour. More studies are needed on ways to combine qualitative approaches with quantitative approaches to inform the development of theory based culturally appropriate and context specific intervention strategies to reduce the risk of HIV. PMID:28090169
An ecological valence theory of human color preference.
Palmer, Stephen E; Schloss, Karen B
2010-05-11
Color preference is an important aspect of visual experience, but little is known about why people in general like some colors more than others. Previous research suggested explanations based on biological adaptations [Hurlbert AC, Ling YL (2007) Curr Biol 17:623-625] and color-emotions [Ou L-C, Luo MR, Woodcock A, Wright A (2004) Color Res Appl 29:381-389]. In this article we articulate an ecological valence theory in which color preferences arise from people's average affective responses to color-associated objects. An empirical test provides strong support for this theory: People like colors strongly associated with objects they like (e.g., blues with clear skies and clean water) and dislike colors strongly associated with objects they dislike (e.g., browns with feces and rotten food). Relative to alternative theories, the ecological valence theory both fits the data better (even with fewer free parameters) and provides a more plausible, comprehensive causal explanation of color preferences.
The Effect of Mini and Midi Anchor Tests on Test Equating
ERIC Educational Resources Information Center
Arikan, Çigdem Akin
2018-01-01
The main purpose of this study is to compare the test forms to the midi anchor test and the mini anchor test performance based on item response theory. The research was conducted with using simulated data which were generated based on Rasch model. In order to equate two test forms the anchor item nonequivalent groups (internal anchor test) was…
ERIC Educational Resources Information Center
Annesi, James J.; Whitaker, Ann C.
2010-01-01
The behavioral processes of weight reduction are poorly understood, and responses to treatments based primarily on caloric restriction have been unfavorable. A theory-based path derived from proposed relations of physical activity, changes in psychological factors, and weight loss was separately tested with women with Class I and Class II obesity…
NASA Astrophysics Data System (ADS)
Zhou, J.; Zeng, X.; Mo, L.; Chen, L.; Jiang, Z.; Feng, Z.; Yuan, L.; He, Z.
2017-12-01
Generally, the adaptive utilization and regulation of runoff in the source region of China's southwest rivers is classified as a typical multi-objective collaborative optimization problem. There are grim competitions and incidence relation in the subsystems of water supply, electricity generation and environment, which leads to a series of complex problems represented by hydrological process variation, blocked electricity output and water environment risk. Mathematically, the difficulties of multi-objective collaborative optimization focus on the description of reciprocal relationships and the establishment of evolving model of adaptive systems. Thus, based on the theory of complex systems science, this project tries to carry out the research from the following aspects: the changing trend of coupled water resource, the covariant factor and driving mechanism, the dynamic evolution law of mutual feedback dynamic process in the supply-generation-environment coupled system, the environmental response and influence mechanism of coupled mutual feedback water resource system, the relationship between leading risk factor and multiple risk based on evolutionary stability and dynamic balance, the transfer mechanism of multiple risk response with the variation of the leading risk factor, the multidimensional coupled feedback system of multiple risk assessment index system and optimized decision theory. Based on the above-mentioned research results, the dynamic method balancing the efficiency of multiple objectives in the coupled feedback system and optimized regulation model of water resources is proposed, and the adaptive scheduling mode considering the internal characteristics and external response of coupled mutual feedback system of water resource is established. In this way, the project can make a contribution to the optimal scheduling theory and methodology of water resource management under uncertainty in the source region of Southwest River.
ERIC Educational Resources Information Center
Wallace, Colin S.; Prather, Edward E.; Duncan, Douglas K.
2012-01-01
This is the third of five papers detailing our national study of general education astronomy students' conceptual and reasoning difficulties with cosmology. In this paper, we use item response theory to analyze students' responses to three out of the four conceptual cosmology surveys we developed. The specific item response theory model we use is…
Exploring the theoretical foundations of visual art programmes for people living with dementia.
Windle, Gill; Gregory, Samantha; Howson-Griffiths, Teri; Newman, Andrew; O'Brien, Dave; Goulding, Anna
2017-01-01
Despite the growing international innovations for visual arts interventions in dementia care, limited attention has been paid to their theoretical basis. In response, this paper explores how and why visual art interventions in dementia care influence changes in outcomes. The theory building process consists of a realist review of primary research on visual art programmes. This aims to uncover what works, for whom, how, why and in what circumstances. We undertook a qualitative exploration of stakeholder perspectives of art programmes, and then synthesised these two pieces of work alongside broader theory to produce a conceptual framework for intervention development, further research and practice. This suggests effective programmes are realised through essential attributes of two key conditions (provocative and stimulating aesthetic experience; dynamic and responsive artistic practice). These conditions are important for cognitive, social and individual responses, leading to benefits for people with early to more advanced dementia. This work represents a starting point at identifying theories of change for arts interventions, and for further research to critically examine, refine and strengthen the evidence base for the arts in dementia care. Understanding the theoretical basis of interventions is important for service development, evaluation and implementation.
Lang, Jonas W B
2014-07-01
The measurement of implicit or unconscious motives using the picture story exercise (PSE) has long been a target of debate in the psychological literature. Most debates have centered on the apparent paradox that PSE measures of implicit motives typically show low internal consistency reliability on common indices like Cronbach's alpha but nevertheless predict behavioral outcomes. I describe a dynamic Thurstonian item response theory (IRT) model that builds on dynamic system theories of motivation, theorizing on the PSE response process, and recent advancements in Thurstonian IRT modeling of choice data. To assess the models' capability to explain the internal consistency paradox, I first fitted the model to archival data (Gurin, Veroff, & Feld, 1957) and then simulated data based on bias-corrected model estimates from the real data. Simulation results revealed that the average squared correlation reliability for the motives in the Thurstonian IRT model was .74 and that Cronbach's alpha values were similar to the real data (<.35). These findings suggest that PSE motive measures have long been reliable and increase the scientific value of extant evidence from motivational research using PSE motive measures. (c) 2014 APA, all rights reserved.
Koppel, Jonathan; Rubin, David C.
2016-01-01
The reminiscence bump is the increased proportion of autobiographical memories from youth and early adulthood observed in adults over 40. It is one of the most robust findings in autobiographical memory research. Although described as a single period of increased memories, a recent meta-analysis which reported the beginning and ending ages of the bump from individual studies found that different classes of cues produce distinct bumps that vary in size and temporal location. The bump obtained in response to cue words is both smaller and located earlier in the lifespan than the bump obtained when important memories are requested. The bump obtained in response to odor cues is even earlier. This variation in the size and location of the reminiscence bump argues for theories based primarily on retrieval rather than encoding and retention, which most current theories stress. Furthermore, it points to the need to develop theories of autobiographical memory that account for this flexibility in the memories retrieved. PMID:27141156
An Introduction to Item Response Theory for Patient-Reported Outcome Measurement
Nguyen, Tam H.; Han, Hae-Ra; Kim, Miyong T.
2015-01-01
The growing emphasis on patient-centered care has accelerated the demand for high-quality data from patient-reported outcome (PRO) measures. Traditionally, the development and validation of these measures has been guided by classical test theory. However, item response theory (IRT), an alternate measurement framework, offers promise for addressing practical measurement problems found in health-related research that have been difficult to solve through classical methods. This paper introduces foundational concepts in IRT, as well as commonly used models and their assumptions. Existing data on a combined sample (n = 636) of Korean American and Vietnamese American adults who responded to the High Blood Pressure Health Literacy Scale and the Patient Health Questionnaire-9 are used to exemplify typical applications of IRT. These examples illustrate how IRT can be used to improve the development, refinement, and evaluation of PRO measures. Greater use of methods based on this framework can increase the accuracy and efficiency with which PROs are measured. PMID:24403095
The study of micro-inextensible piezoelectric cantilever plate
NASA Astrophysics Data System (ADS)
Chen, L. H.; Xu, J. W.; Zhang, W.
2018-06-01
In this paper, a micro-inextensible piezoelectric cantilever plate is analyzed and its nonlinear dynamic behaviour is studied. The nonlinear oscillation differential equation is established by using Hamilton’s principle with the application of strain gradient theory to consider the size effect, and inextensible theory to consider the large deformation and rotation effect of cantilever plate. Based on MATLAB software, using the Runge-Kuta method, we can obtain the response of the nonlinear oscillation differential equation. The influences of the strain gradient length scale parameter and voltage on the dynamic response of micro piezoelectric cantilever plate are investigated separately. The results confirmed an increase of the stiffness of the system by using the strain gradient theory and the amplitude of the vibration is reduced. The vibration of the system can be controlled by applying an active voltage. The effect of external excitation frequency on nonlinear dynamic behaviour is considered by using Poincare surface of section and diagrams of waveforms, phase and bifurcation.
An introduction to item response theory for patient-reported outcome measurement.
Nguyen, Tam H; Han, Hae-Ra; Kim, Miyong T; Chan, Kitty S
2014-01-01
The growing emphasis on patient-centered care has accelerated the demand for high-quality data from patient-reported outcome (PRO) measures. Traditionally, the development and validation of these measures has been guided by classical test theory. However, item response theory (IRT), an alternate measurement framework, offers promise for addressing practical measurement problems found in health-related research that have been difficult to solve through classical methods. This paper introduces foundational concepts in IRT, as well as commonly used models and their assumptions. Existing data on a combined sample (n = 636) of Korean American and Vietnamese American adults who responded to the High Blood Pressure Health Literacy Scale and the Patient Health Questionnaire-9 are used to exemplify typical applications of IRT. These examples illustrate how IRT can be used to improve the development, refinement, and evaluation of PRO measures. Greater use of methods based on this framework can increase the accuracy and efficiency with which PROs are measured.
Item response theory analysis of the Pain Self-Efficacy Questionnaire.
Costa, Daniel S J; Asghari, Ali; Nicholas, Michael K
2017-01-01
The Pain Self-Efficacy Questionnaire (PSEQ) is a 10-item instrument designed to assess the extent to which a person in pain believes s/he is able to accomplish various activities despite their pain. There is strong evidence for the validity and reliability of both the full-length PSEQ and a 2-item version. The purpose of this study is to further examine the properties of the PSEQ using an item response theory (IRT) approach. We used the two-parameter graded response model to examine the category probability curves, and location and discrimination parameters of the 10 PSEQ items. In item response theory, responses to a set of items are assumed to be probabilistically determined by a latent (unobserved) variable. In the graded-response model specifically, item response threshold (the value of the latent variable for which adjacent response categories are equally likely) and discrimination parameters are estimated for each item. Participants were 1511 mixed, chronic pain patients attending for initial assessment at a tertiary pain management centre. All items except item 7 ('I can cope with my pain without medication') performed well in IRT analysis, and the category probability curves suggested that participants used the 7-point response scale consistently. Items 6 ('I can still do many of the things I enjoy doing, such as hobbies or leisure activity, despite pain'), 8 ('I can still accomplish most of my goals in life, despite the pain') and 9 ('I can live a normal lifestyle, despite the pain') captured higher levels of the latent variable with greater precision. The results from this IRT analysis add to the body of evidence based on classical test theory illustrating the strong psychometric properties of the PSEQ. Despite the relatively poor performance of Item 7, its clinical utility warrants its retention in the questionnaire. The strong psychometric properties of the PSEQ support its use as an effective tool for assessing self-efficacy in people with pain. Copyright © 2016 Scandinavian Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
Adjoint-based constant-mass partial derivatives
Favorite, Jeffrey A.
2017-09-01
In transport theory, adjoint-based partial derivatives with respect to mass density are constant-volume derivatives. Likewise, adjoint-based partial derivatives with respect to surface locations (i.e., internal interface locations and the outer system boundary) are constant-density derivatives. This study derives the constant-mass partial derivative of a response with respect to an internal interface location or the outer system boundary and the constant-mass partial derivative of a response with respect to the mass density of a region. Numerical results are given for a multiregion two-dimensional (r-z) cylinder for three very different responses: the uncollided gamma-ray flux at an external detector point, k effmore » of the system, and the total neutron leakage. Finally, results from the derived formulas compare extremely well with direct perturbation calculations.« less
Compound cuing in free recall.
Lohnas, Lynn J; Kahana, Michael J
2014-01-01
According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cuing in free recall. Specifically, the temporal contiguity effect should be greater when the 2 most recently recalled items were studied in contiguous list positions. A meta-analysis of published free recall experiments demonstrates evidence for compound cuing in both conditional response probabilities and interresponse times. To help rule out a rehearsal-based account of these compound cuing effects, we conducted an experiment with immediate, delayed, and continual-distractor free recall conditions. Consistent with retrieved context theory but not with a rehearsal-based account, compound cuing was present in all conditions, and was not significantly influenced by the presence of interitem distractors.
Placebo effect in clinical trial design for irritable bowel syndrome.
Shah, Eric; Pimentel, Mark
2014-04-30
Ongoing efforts to improve clinical trial design in irritable bowel syndrome have been hindered by high placebo response rates and ineffective outcome measures. We assessed established strategies to minimize placebo effect as well as the various ap-proaches to placebo effect which can affect trial design. These include genetic markers such as catechol-O-methyltransferase, opioidergic and dopaminergic neurobiologic theory, pre-cebo effect centered on expectancy theory, and side effect unblinding grounded on conditioning theory. We reviewed endpoints used in the study of IBS over the past decade including adequate relief and subjective global relief, emphasizing their weaknesses in fully evaluating the IBS condition, specifically their motility effects based on functional net value and relative benefit-harm based on dropouts due to adverse events. The focus of this review is to highlight ongoing efforts to improve clinical trial design which can lead to better outcomes in a real-world setting.
Social judgment theory based model on opinion formation, polarization and evolution
NASA Astrophysics Data System (ADS)
Chau, H. F.; Wong, C. Y.; Chow, F. K.; Fung, Chi-Hang Fred
2014-12-01
The dynamical origin of opinion polarization in the real world is an interesting topic that physical scientists may help to understand. To properly model the dynamics, the theory must be fully compatible with findings by social psychologists on microscopic opinion change. Here we introduce a generic model of opinion formation with homogeneous agents based on the well-known social judgment theory in social psychology by extending a similar model proposed by Jager and Amblard. The agents’ opinions will eventually cluster around extreme and/or moderate opinions forming three phases in a two-dimensional parameter space that describes the microscopic opinion response of the agents. The dynamics of this model can be qualitatively understood by mean-field analysis. More importantly, first-order phase transition in opinion distribution is observed by evolving the system under a slow change in the system parameters, showing that punctuated equilibria in public opinion can occur even in a fully connected social network.
NASA Technical Reports Server (NTRS)
Waszak, Martin R.
1992-01-01
The application of a sector-based stability theory approach to the formulation of useful uncertainty descriptions for linear, time-invariant, multivariable systems is explored. A review of basic sector properties and sector-based approach are presented first. The sector-based approach is then applied to several general forms of parameter uncertainty to investigate its advantages and limitations. The results indicate that the sector uncertainty bound can be used effectively to evaluate the impact of parameter uncertainties on the frequency response of the design model. Inherent conservatism is a potential limitation of the sector-based approach, especially for highly dependent uncertain parameters. In addition, the representation of the system dynamics can affect the amount of conservatism reflected in the sector bound. Careful application of the model can help to reduce this conservatism, however, and the solution approach has some degrees of freedom that may be further exploited to reduce the conservatism.
2010-01-01
Background Patients-Reported Outcomes (PRO) are increasingly used in clinical and epidemiological research. Two main types of analytical strategies can be found for these data: classical test theory (CTT) based on the observed scores and models coming from Item Response Theory (IRT). However, whether IRT or CTT would be the most appropriate method to analyse PRO data remains unknown. The statistical properties of CTT and IRT, regarding power and corresponding effect sizes, were compared. Methods Two-group cross-sectional studies were simulated for the comparison of PRO data using IRT or CTT-based analysis. For IRT, different scenarios were investigated according to whether items or person parameters were assumed to be known, to a certain extent for item parameters, from good to poor precision, or unknown and therefore had to be estimated. The powers obtained with IRT or CTT were compared and parameters having the strongest impact on them were identified. Results When person parameters were assumed to be unknown and items parameters to be either known or not, the power achieved using IRT or CTT were similar and always lower than the expected power using the well-known sample size formula for normally distributed endpoints. The number of items had a substantial impact on power for both methods. Conclusion Without any missing data, IRT and CTT seem to provide comparable power. The classical sample size formula for CTT seems to be adequate under some conditions but is not appropriate for IRT. In IRT, it seems important to take account of the number of items to obtain an accurate formula. PMID:20338031
Item response theory - A first approach
NASA Astrophysics Data System (ADS)
Nunes, Sandra; Oliveira, Teresa; Oliveira, Amílcar
2017-07-01
The Item Response Theory (IRT) has become one of the most popular scoring frameworks for measurement data, frequently used in computerized adaptive testing, cognitively diagnostic assessment and test equating. According to Andrade et al. (2000), IRT can be defined as a set of mathematical models (Item Response Models - IRM) constructed to represent the probability of an individual giving the right answer to an item of a particular test. The number of Item Responsible Models available to measurement analysis has increased considerably in the last fifteen years due to increasing computer power and due to a demand for accuracy and more meaningful inferences grounded in complex data. The developments in modeling with Item Response Theory were related with developments in estimation theory, most remarkably Bayesian estimation with Markov chain Monte Carlo algorithms (Patz & Junker, 1999). The popularity of Item Response Theory has also implied numerous overviews in books and journals, and many connections between IRT and other statistical estimation procedures, such as factor analysis and structural equation modeling, have been made repeatedly (Van der Lindem & Hambleton, 1997). As stated before the Item Response Theory covers a variety of measurement models, ranging from basic one-dimensional models for dichotomously and polytomously scored items and their multidimensional analogues to models that incorporate information about cognitive sub-processes which influence the overall item response process. The aim of this work is to introduce the main concepts associated with one-dimensional models of Item Response Theory, to specify the logistic models with one, two and three parameters, to discuss some properties of these models and to present the main estimation procedures.
Counseling Supervision within a Feminist Framework: Guidelines for Intervention
ERIC Educational Resources Information Center
Degges-White, Suzanne E.; Colon, Bonnie R.; Borzumato-Gainey, Christine
2013-01-01
Feminist supervision is based on the principles of feminist theory. Goals include sharing responsibility for the supervision process, empowering the supervisee, attending to the contextual assumptions about clients, and analyzing gender roles. This article explores feminist supervision and guidelines for providing counseling supervision…
Multiscale Modeling of Deformation Twinning Based on Field Theory of Multiscale Plasticity (FTMP)
2013-09-01
of the deformation twinning: nucleation, growth (into, e.g., lenticular shapes), lattice rotation (satisfying the mirror symmetry), the attendant...Nucleation and subsequent growth into lenticular shapes is realistically captured. • Stress-strain responses accompanied by serration and overall softening
ERIC Educational Resources Information Center
Whitehead, Jack
1989-01-01
Considers educational values and the constraints placed upon the realization of these values in the workplace. Discusses how the abuse of institutional power undermines the responsibilities accompanying academic freedom. (KO)
Teaching Literature to Adolescents
ERIC Educational Resources Information Center
Beach, Richard W.; Appleman, Deborah; Hynds, Susan; Wilhelm, Jeffrey
2006-01-01
This text for pre-service and in-service English education courses presents current methods of teaching literature to middle and high school students. The methods are based on social constructivist/socio-cultural theories of literacy learning, and incorporate research on literary response conducted by the authors. "Teaching Literature to…
Towards a Cyber-Constructivist Perspective (CCP) of Educational Design
ERIC Educational Resources Information Center
Luppicini, Rocci
2003-01-01
This theoretical paper utilizes cybernetic-based approaches (Bopry, 1999; Wiener, 1954) and communications theory (Habermas, 1984, 1990; Krippendorff, 1994) to advance knowledge of constructivist learning. I argue that past educational research literature on constructivist learning is partly responsible for limiting how educational designers…
Rationalizing Neglect: An Institutional Response to Transfer Students
ERIC Educational Resources Information Center
Tobolowsky, Barbara F.; Cox, Bradley E.
2012-01-01
This qualitative study focuses on institutional efforts affecting the transfer student experience at a single research institution. Findings based on interviews with institutional representatives, both faculty and staff, using the rational, natural, and open system perspectives of organizational theory, provide insights into the institutional…
A New Functional Health Literacy Scale for Japanese Young Adults Based on Item Response Theory.
Tsubakita, Takashi; Kawazoe, Nobuo; Kasano, Eri
2017-03-01
Health literacy predicts health outcomes. Despite concerns surrounding the health of Japanese young adults, to date there has been no objective assessment of health literacy in this population. This study aimed to develop a Functional Health Literacy Scale for Young Adults (funHLS-YA) based on item response theory. Each item in the scale requires participants to choose the most relevant term from 3 choices in relation to a target item, thus assessing objective rather than perceived health literacy. The 20-item scale was administered to 1816 university students and 1751 responded. Cronbach's α coefficient was .73. Difficulty and discrimination parameters of each item were estimated, resulting in the exclusion of 1 item. Some items showed different difficulty parameters for male and female participants, reflecting that some aspects of health literacy may differ by gender. The current 19-item version of funHLS-YA can reliably assess the objective health literacy of Japanese young adults.
An Analysis of the Connectedness to Nature Scale Based on Item Response Theory
Pasca, Laura; Aragonés, Juan I.; Coello, María T.
2017-01-01
The Connectedness to Nature Scale (CNS) is used as a measure of the subjective cognitive connection between individuals and nature. However, to date, it has not been analyzed at the item level to confirm its quality. In the present study, we conduct such an analysis based on Item Response Theory. We employed data from previous studies using the Spanish-language version of the CNS, analyzing a sample of 1008 participants. The results show that seven items presented appropriate indices of discrimination and difficulty, in addition to a good fit. The remaining six have inadequate discrimination indices and do not present a good fit. A second study with 321 participants shows that the seven-item scale has adequate levels of reliability and validity. Therefore, it would be appropriate to use a reduced version of the scale after eliminating the items that display inappropriate behavior, since they may interfere with research results on connectedness to nature. PMID:28824509
NASA Astrophysics Data System (ADS)
Liu, Yuxin; Huang, Zhitong; Li, Wei; Ji, Yuefeng
2016-03-01
Various patterns of device-to-device (D2D) communication, from Bluetooth to Wi-Fi Direct, are emerging due to the increasing requirements of information sharing between mobile terminals. This paper presents an innovative pattern named device-to-device visible light communication (D2D-VLC) to alleviate the growing traffic problem. However, the occlusion problem is a difficulty in D2D-VLC. This paper proposes a game theory-based solution in which the best-response dynamics and best-response strategies are used to realize a mode-cooperative selection mechanism. This mechanism uses system capacity as the utility function to optimize system performance and selects the optimal communication mode for each active user from three candidate modes. Moreover, the simulation and experimental results show that the mechanism can attain a significant improvement in terms of effectiveness and energy saving compared with the cases where the users communicate via only the fixed transceivers (light-emitting diode and photo diode) or via only D2D.
ERIC Educational Resources Information Center
Schilling, Stephen G.
2007-01-01
In this paper the author examines the role of item response theory (IRT), particularly multidimensional item response theory (MIRT) in test validation from a validity argument perspective. The author provides justification for several structural assumptions and interpretations, taking care to describe the role he believes they should play in any…
Examination of Different Item Response Theory Models on Tests Composed of Testlets
ERIC Educational Resources Information Center
Kogar, Esin Yilmaz; Kelecioglu, Hülya
2017-01-01
The purpose of this research is to first estimate the item and ability parameters and the standard error values related to those parameters obtained from Unidimensional Item Response Theory (UIRT), bifactor (BIF) and Testlet Response Theory models (TRT) in the tests including testlets, when the number of testlets, number of independent items, and…
Valt, Christian; Klein, Christoph; Boehm, Stephan G
2015-08-01
Repetition priming is a prominent example of non-declarative memory, and it increases the accuracy and speed of responses to repeatedly processed stimuli. Major long-hold memory theories posit that repetition priming results from facilitation within perceptual and conceptual networks for stimulus recognition and categorization. Stimuli can also be bound to particular responses, and it has recently been suggested that this rapid response learning, not network facilitation, provides a sound theory of priming of object recognition. Here, we addressed the relevance of network facilitation and rapid response learning for priming of person recognition with a view to advance general theories of priming. In four experiments, participants performed conceptual decisions like occupation or nationality judgments for famous faces. The magnitude of rapid response learning varied across experiments, and rapid response learning co-occurred and interacted with facilitation in perceptual and conceptual networks. These findings indicate that rapid response learning and facilitation in perceptual and conceptual networks are complementary rather than competing theories of priming. Thus, future memory theories need to incorporate both rapid response learning and network facilitation as individual facets of priming. © 2014 The British Psychological Society.
Unified-theory-of-reinforcement neural networks do not simulate the blocking effect.
Calvin, Nicholas T; J McDowell, J
2015-11-01
For the last 20 years the unified theory of reinforcement (Donahoe et al., 1993) has been used to develop computer simulations to evaluate its plausibility as an account for behavior. The unified theory of reinforcement states that operant and respondent learning occurs via the same neural mechanisms. As part of a larger project to evaluate the operant behavior predicted by the theory, this project was the first replication of neural network models based on the unified theory of reinforcement. In the process of replicating these neural network models it became apparent that a previously published finding, namely, that the networks simulate the blocking phenomenon (Donahoe et al., 1993), was a misinterpretation of the data. We show that the apparent blocking produced by these networks is an artifact of the inability of these networks to generate the same conditioned response to multiple stimuli. The piecemeal approach to evaluate the unified theory of reinforcement via simulation is critiqued and alternatives are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.
Finding common ground in implementation: towards a theory of gradual commonality.
Ter Haar, Marian; Aarts, Noelle; Verhoeven, Piet
2016-03-01
This article reports on an empirical study that aimed to design a practice-based theory about collaboration on the local implementation of a nationally developed health-promoting intervention. The study's objective is to better understand the dynamic process of complex collaboration. The research is based on a Delphi study among some 100 individuals in local and regional networks, in which various professionals work together to implement the BeweegKuur, which translates as 'course of exercise'. The BeweegKuur is a combined lifestyle intervention aimed at promoting sufficient physical exercise and a healthy diet among people in the Netherlands who are overweight and at risk of diabetes. The Delphi study in three rounds systematically and interactively constructs a common perspective on implementation, reflecting stakeholders' ideas about the collaboration and providing an insight into how these ideas are influenced by the context of the implementation. The statistical and qualitative analyses of the responses to the feedback in the Delphi study form the basis for this practice-based theory on complex collaboration, called the theory of gradual commonality. During interaction, consensus gradually emerges about co-creation as a collaboration strategy. Co-creation leaves room for various ways of achieving the ambitions of the BeweegKuur. This article discusses the importance of this practice-based theory and the value of the Delphi research strategy for promoting health. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Ince, Mustafa Levent
2008-12-01
The purpose of this study was to examine the effects of a 12-wk. physical activity intervention, based on conceptual discussions and practices of a social cognitive theory on health-promoting behaviors of 62 university students. The intervention mainly focused on development of self-regulatory skills, social support, and self-assessment of health-related fitness. The Adolescent Health Promotion Scale and International Physical Activity Questionnaire were given. Analysis of self-reports indicated improved nutrition, health responsibility, social support, exercise, stress management, and overall health from pre- to postintervention. Also, participants' postintervention reports of moderate, vigorous, and total physical activity were higher than at preintervention.
NASA Astrophysics Data System (ADS)
Xue, Zhang-Na; Yu, Ya-Jun; Tian, Xiao-Geng
2017-07-01
Based upon the coupled thermoelasticity and Green and Lindsay theory, the new governing equations of two-temperature thermoelastic theory with thermal nonlocal parameter is formulated. To more realistically model thermal loading of a half-space surface, a linear temperature ramping function is adopted. Laplace transform techniques are used to get the general analytical solutions in Laplace domain, and the inverse Laplace transforms based on Fourier expansion techniques are numerically implemented to obtain the numerical solutions in time domain. Specific attention is paid to study the effect of thermal nonlocal parameter, ramping time, and two-temperature parameter on the distributions of temperature, displacement and stress distribution.
Haase, S J; Fisk, G
2001-01-01
The present experiments extend the scope of the independent observation model based on signal detection theory (Macmillan & Creelman, 1991) to complex (word) stimulus sets. In the first experiment, the model predicts the relationship between uncertain detection and subsequent correct identification, thereby providing an alternative interpretation to a phenomenon often described as unconscious perception. Our second experiment used an exclusion task (Jacoby, Toth, & Yonelinas, 1993), which, according to theories of unconscious perception, should show qualitative differences in performance based on stimulus detection accuracy and provide a relative measure of conscious versus unconscious influences (Merikle, Joordens, & Stoltz, 1995). Exclusion performance was also explained by the model, suggesting that undetected words did not unconsciously influence identification responses.
On the physical basis of a theory of human thermoregulation.
NASA Technical Reports Server (NTRS)
Iberall, A. S.; Schindler, A. M.
1973-01-01
Theoretical study of the physical factors which are responsible for thermoregulation in nude resting humans in a physical steady state. The behavior of oxidative metabolism, evaporative and convective thermal fluxes, fluid heat transfer, internal and surface temperatures, and evaporative phase transitions is studied by physiological/physical modeling techniques. The modeling is based on the theories that the body has a vital core with autothermoregulation, that the vital core contracts longitudinally, that the temperature of peripheral regions and extremities decreases towards the ambient, and that a significant portion of the evaporative heat may be lost underneath the skin. A theoretical basis is derived for a consistent modeling of steady-state thermoregulation on the basis of these theories.
Vibration responses of h-BN sheet to charge doping and external strain
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Wei; Yang, Yu; Zheng, Fawei
2013-12-07
Based on density functional theory and density functional perturbation theory calculations, we systematically investigate the vibration responses of h-BN sheet to charge doping and external strains. It is found that under hole doping, the phonon frequencies of the ZO and TO branches at different wave vector q shift linearly with different slopes. Under electron doping, although the phonon frequencies shift irregularly, the shifting values are different at different phonon wave vectors. Interestingly, we find that external strain can restrain the irregular vibration responses of h-BN sheet to electron doping. The critical factor is revealed to be the relative position ofmore » the nearly free electron and boron p{sub z} states of h-BN sheet. Under external strains, the vibration responses of h-BN sheet are also found to be highly dependent on the phonon branches. Different vibration modes at different q points are revealed to be responsible for the vibration responses of h-BN sheet to charge doping and external strain. Our results point out a new way to detect the doping or strain status of h-BN sheet by measuring the vibration frequencies at different wave vector.« less
Harris, Rebecca; Mosedale, Sarah; Garner, Jayne; Perkins, Elizabeth
2014-05-01
UK NHS contracts mediate the relationship between dental and medical practitioners as independent contractors, and the state which reimburses them for their services to patients. There have been successive revisions of dental and medical contracts since the 1990s alongside a change in the levels of professional dominance and accountability. Unintended consequences of the 2006 dental contract have led to plans for further reform. We set out to identify the factors which facilitate and hinder the use of contracts in this area. Previous reviews of theory have been narrative, and based on macro-theory arising from various disciplines such as economics, sociology and political science. This paper presents a systematic review and aggregative synthesis of the theories of contracting for publicly funded health care. A logic map conveys internal pathways linking competition for contracts to opportunism. We identify that whilst practitioners' responses to contract rules is a result of micro-level bargaining clarifying patients' and providers' interests, responses are also influenced by relationships with commissioners and wider personal, professional and political networks. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Justification of Galston's liberal pluralism.
Azam, Golam
2016-01-01
Liberal multicultural theories developed in late twenty-first century aims to ensure the rights of the minorities, social justice and harmony in liberal societies. Will Kymlicka is the leading philosopher in this field. He advocates minority rights, their autonomy and the way minority groups can be accommodated in a liberal society with their distinct cultural identity. Besides him, there are other political theorists on the track and Galston is one of them. He disagrees with Kymlicka on some crucial points, particularly regarding the scope of civil rights of the minority groups and the responsibilities of both majority and minority groups for the sake of social harmony and justice. He tries to develop a moral theory of mutualism based on inter-community toleration and constitutionalism. Considering toleration as one of the fundamental liberal virtues he contends that the majority government has the responsibility to make arrangement both for the members of majority and minority groups so that they can build inter personal relation and learn toleration. The paper critically justifies the feasibility of his theory in a liberal society and claims that although Galston's theory has a higher possibility to be accommodated in liberal societies, it eventually fails.
Testing the predictions of coping styles theory in threespined sticklebacks
Bensky, Miles K.; Paitz, Ryan; Pereira, Laura; Bell, Alison M.
2017-01-01
Coping styles theory provides a framework for understanding individual variation in how animals respond to environmental change, and predicts how individual differences in stress responsiveness and behavior might relate to cognitive differences. According to coping styles theory, proactive individuals are bolder, less reactive to stressors, and more routinized than their reactive counterparts. A key tenet of coping styles theory is that variation in coping styles is maintained by tradeoffs with behavioral flexibility: proactive individuals excel in stable environments while more flexible, reactive individuals perform better in variable environments. Here, we assess evidence for coping styles within a natural population of threespined sticklebacks (Gasterosteus aculeatus). We developed a criterion-based learning paradigm to evaluate individual variation in initial and reversal learning. We observed strong individual differences in boldness, cortisol production, and learning performance. Consistent with coping styles, fish that released more cortisol were more timid in response to a predator attack and slower to learn a color discrimination task. However, there was no evidence that reactive individuals performed better when the environment changed (when the rewarded color was reversed). The failure to detect trade-offs between behavioral routinization and flexibility prompts other explanations for the maintenance of differing coping styles. PMID:28017848
NASA Astrophysics Data System (ADS)
Fa, L. N.
2017-11-01
As the important Environmental Interests of Subjects, government behooves to undertake the corresponding responsibility of Pollution Control and Environmental Protection. The current situations in our country, however, appear as government environmental responsibility failure. Based on the analysis of law and economics, this article reaches the conclusion through game analysis, principle-agency relationship and utility theory that the prisoners dilemma of environmental interest game between government and enterprise, and the inherent defect of the principal-agency relationship between central government and local government are the inherent causes of government environmental responsibility failure. Many officials tends to graft and corrupt to maximum their own benefit, thus leading to the government failure among environmental pollution treatment and the environmental responsibility to undertake.
Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee
2013-07-01
Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.
Kinetically-Defined Component Actions in Gene Repression
Chow, Carson C.; Finn, Kelsey K.; Storchan, Geoffery B.; Lu, Xinping; Sheng, Xiaoyan; Simons, S. Stoney
2015-01-01
Gene repression by transcription factors, and glucocorticoid receptors (GR) in particular, is a critical, but poorly understood, physiological response. Among the many unresolved questions is the difference between GR regulated induction and repression, and whether transcription cofactor action is the same in both. Because activity classifications based on changes in gene product level are mechanistically uninformative, we present a theory for gene repression in which the mechanisms of factor action are defined kinetically and are consistent for both gene repression and induction. The theory is generally applicable and amenable to predictions if the dose-response curve for gene repression is non-cooperative with a unit Hill coefficient, which is observed for GR-regulated repression of AP1LUC reporter induction by phorbol myristate acetate. The theory predicts the mechanism of GR and cofactors, and where they act with respect to each other, based on how each cofactor alters the plots of various kinetic parameters vs. cofactor. We show that the kinetically-defined mechanism of action of each of four factors (reporter gene, p160 coactivator TIF2, and two pharmaceuticals [NU6027 and phenanthroline]) is the same in GR-regulated repression and induction. What differs is the position of GR action. This insight should simplify clinical efforts to differentially modulate factor actions in gene induction vs. gene repression. PMID:25816223
Morozov, Andrew; Petrovskii, Sergei
2013-01-01
Understanding of complex trophic interactions in ecosystems requires correct descriptions of the rate at which predators consume a variety of different prey species. Field and laboratory data on multispecies communities are rarely sufficient and usually cannot provide an unambiguous test for the theory. As a result, the conventional way of constructing a multi-prey functional response is speculative, and often based on assumptions that are difficult to verify. Predator responses allowing for prey selectivity and active switching are thought to be more biologically relevant compared to the standard proportion-based consumption. However, here we argue that the functional responses with switching may not be applicable to communities with a broad spectrum of resource types. We formulate a set of general rules that a biologically sound parameterization of a predator functional response should satisfy, and show that all existing formulations for the multispecies response with prey selectivity and switching fail to do so. Finally, we propose a universal framework for parameterization of a multi-prey functional response by combining patterns of food selectivity and proportion-based feeding. PMID:24086356
A New Method for a Virtue-Based Responsible Conduct of Research Curriculum: Pilot Test Results.
Berling, Eric; McLeskey, Chet; O'Rourke, Michael; Pennock, Robert T
2018-02-03
Drawing on Pennock's theory of scientific virtues, we are developing an alternative curriculum for training scientists in the responsible conduct of research (RCR) that emphasizes internal values rather than externally imposed rules. This approach focuses on the virtuous characteristics of scientists that lead to responsible and exemplary behavior. We have been pilot-testing one element of such a virtue-based approach to RCR training by conducting dialogue sessions, modeled upon the approach developed by Toolbox Dialogue Initiative, that focus on a specific virtue, e.g., curiosity and objectivity. During these structured discussions, small groups of scientists explore the roles they think the focus virtue plays and should play in the practice of science. Preliminary results have shown that participants strongly prefer this virtue-based model over traditional methods of RCR training. While we cannot yet definitively say that participation in these RCR sessions contributes to responsible conduct, these pilot results are encouraging and warrant continued development of this virtue-based approach to RCR training.
Modeling silicon diode energy response factors for use in therapeutic photon beams.
Eklund, Karin; Ahnesjö, Anders
2009-10-21
Silicon diodes have good spatial resolution, which makes them advantageous over ionization chambers for dosimetry in fields with high dose gradients. However, silicon diodes overrespond to low-energy photons, that are more abundant in scatter which increase with large fields and larger depths. We present a cavity-theory-based model for a general response function for silicon detectors at arbitrary positions within photon fields. The model uses photon and electron spectra calculated from fluence pencil kernels. The incident photons are treated according to their energy through a bipartition of the primary beam photon spectrum into low- and high-energy components. Primary electrons from the high-energy component are treated according to Spencer-Attix cavity theory. Low-energy primary photons together with all scattered photons are treated according to large cavity theory supplemented with an energy-dependent factor K(E) to compensate for energy variations in the electron equilibrium. The depth variation of the response for an unshielded silicon detector has been calculated for 5 x 5 cm(2), 10 x 10 cm(2) and 20 x 20 cm(2) fields in 6 and 15 MV beams and compared with measurements showing that our model calculates response factors with deviations less than 0.6%. An alternative method is also proposed, where we show that one can use a correlation with the scatter factor to determine the detector response of silicon diodes with an error of less than 3% in 6 MV and 15 MV photon beams.
Reduced-Order Models Based on Linear and Nonlinear Aerodynamic Impulse Responses
NASA Technical Reports Server (NTRS)
Silva, Walter A.
1999-01-01
This paper discusses a method for the identification and application of reduced-order models based on linear and nonlinear aerodynamic impulse responses. The Volterra theory of nonlinear systems and an appropriate kernel identification technique are described. Insight into the nature of kernels is provided by applying the method to the nonlinear Riccati equation in a non-aerodynamic application. The method is then applied to a nonlinear aerodynamic model of RAE 2822 supercritical airfoil undergoing plunge motions using the CFL3D Navier-Stokes flow solver with the Spalart-Allmaras turbulence model. Results demonstrate the computational efficiency of the technique.
Reduced Order Models Based on Linear and Nonlinear Aerodynamic Impulse Responses
NASA Technical Reports Server (NTRS)
Silva, Walter A.
1999-01-01
This paper discusses a method for the identification and application of reduced-order models based on linear and nonlinear aerodynamic impulse responses. The Volterra theory of nonlinear systems and an appropriate kernel identification technique are described. Insight into the nature of kernels is provided by applying the method to the nonlinear Riccati equation in a non-aerodynamic application. The method is then applied to a nonlinear aerodynamic model of an RAE 2822 supercritical airfoil undergoing plunge motions using the CFL3D Navier-Stokes flow solver with the Spalart-Allmaras turbulence model. Results demonstrate the computational efficiency of the technique.
Scalable and responsive event processing in the cloud
Suresh, Visalakshmi; Ezhilchelvan, Paul; Watson, Paul
2013-01-01
Event processing involves continuous evaluation of queries over streams of events. Response-time optimization is traditionally done over a fixed set of nodes and/or by using metrics measured at query-operator levels. Cloud computing makes it easy to acquire and release computing nodes as required. Leveraging this flexibility, we propose a novel, queueing-theory-based approach for meeting specified response-time targets against fluctuating event arrival rates by drawing only the necessary amount of computing resources from a cloud platform. In the proposed approach, the entire processing engine of a distinct query is modelled as an atomic unit for predicting response times. Several such units hosted on a single node are modelled as a multiple class M/G/1 system. These aspects eliminate intrusive, low-level performance measurements at run-time, and also offer portability and scalability. Using model-based predictions, cloud resources are efficiently used to meet response-time targets. The efficacy of the approach is demonstrated through cloud-based experiments. PMID:23230164
NASA Astrophysics Data System (ADS)
Heinrich, S. M.; Wenzel, M. J.; Josse, F.; Dufour, I.
2009-06-01
The problem governing the transient deformation of an elastic cantilever beam with viscoelastic coating, subjected to a time-dependent coating eigenstrain, is mathematically formulated. An analytical solution for an exponential eigenstrain history, exact within the context of beam theory, is obtained in terms of the coating and base layer thicknesses, the elastic modulus of the base material, the initial coating modulus, the coating relaxation percentage (0%-100%), and the time constants of the coating's relaxation process and its eigenstrain history. Approximate formulas, valid for thin coatings, are derived as special cases to provide insight into system behavior. Main results include (1) the time histories of the beam curvature and the coating stresses, (2) a criterion governing the response type (monotonic or "overshoot" response), and (3) simple expressions for the overshoot ratio, defined as the peak response scaled by the steady-state response, and the time at which the peak response occurs. Applications to polymer-coated microcantilever-based chemical sensors operating in the static mode are discussed.
The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission.
Kiani, Mehdi; Ghovanloo, Maysam
2012-09-01
Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor ( Q ) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory.
The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission
Kiani, Mehdi; Ghovanloo, Maysam
2014-01-01
Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor (Q) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory. PMID:24683368
Dissociating action-effect activation and effect-based response selection.
Schwarz, Katharina A; Pfister, Roland; Wirth, Robert; Kunde, Wilfried
2018-05-25
Anticipated action effects have been shown to govern action selection and initiation, as described in ideomotor theory, and they have also been demonstrated to determine crosstalk between different tasks in multitasking studies. Such effect-based crosstalk was observed not only in a forward manner (with a first task influencing performance in a following second task) but also in a backward manner (the second task influencing the preceding first task), suggesting that action effect codes can become activated prior to a capacity-limited processing stage often denoted as response selection. The process of effect-based response production, by contrast, has been proposed to be capacity-limited. These observations jointly suggest that effect code activation can occur independently of effect-based response production, though this theoretical implication has not been tested directly at present. We tested this hypothesis by employing a dual-task set-up in which we manipulated the ease of effect-based response production (via response-effect compatibility) in an experimental design that allows for observing forward and backward crosstalk. We observed robust crosstalk effects and response-effect compatibility effects alike, but no interaction between both effects. These results indicate that effect activation can occur in parallel for several tasks, independently of effect-based response production, which is confined to one task at a time. Copyright © 2018 Elsevier B.V. All rights reserved.
Xue, Ling; Holford, Nick; Ding, Xiao-Liang; Shen, Zhen-Ya; Huang, Chen-Rong; Zhang, Hua; Zhang, Jing-Jing; Guo, Zhe-Ning; Xie, Cheng; Zhou, Ling; Chen, Zhi-Yao; Liu, Lin-Sheng; Miao, Li-Yan
2017-04-01
The aims of this study are to apply a theory-based mechanistic model to describe the pharmacokinetics (PK) and pharmacodynamics (PD) of S- and R-warfarin. Clinical data were obtained from 264 patients. Total concentrations for S- and R-warfarin were measured by ultra-high performance liquid tandem mass spectrometry. Genotypes were measured using pyrosequencing. A sequential population PK parameter with data method was used to describe the international normalized ratio (INR) time course. Data were analyzed with NONMEM. Model evaluation was based on parameter plausibility and prediction-corrected visual predictive checks. Warfarin PK was described using a one-compartment model. CYP2C9 *1/*3 genotype had reduced clearance for S-warfarin, but increased clearance for R-warfarin. The in vitro parameters for the relationship between prothrombin complex activity (PCA) and INR were markedly different (A = 0.560, B = 0.386) from the theory-based values (A = 1, B = 0). There was a small difference between healthy subjects and patients. A sigmoid E max PD model inhibiting PCA synthesis as a function of S-warfarin concentration predicted INR. Small R-warfarin effects was described by competitive antagonism of S-warfarin inhibition. Patients with VKORC1 AA and CYP4F2 CC or CT genotypes had lower C50 for S-warfarin. A theory-based PKPD model describes warfarin concentrations and clinical response. Expected PK and PD genotype effects were confirmed. The role of predicted fat free mass with theory-based allometric scaling of PK parameters was identified. R-warfarin had a minor effect compared with S-warfarin on PCA synthesis. INR is predictable from 1/PCA in vivo. © 2016 The British Pharmacological Society.
NASA Astrophysics Data System (ADS)
Cheng, Lin; Yang, Yongqing; Li, Li; Sui, Xin
2018-06-01
This paper studies the finite-time hybrid projective synchronization of the drive-response complex networks. In the model, general transmission delays and distributed delays are also considered. By designing the adaptive intermittent controllers, the response network can achieve hybrid projective synchronization with the drive system in finite time. Based on finite-time stability theory and several differential inequalities, some simple finite-time hybrid projective synchronization criteria are derived. Two numerical examples are given to illustrate the effectiveness of the proposed method.
Chen, Peng; Zhang, Jiquan; Sun, Yingyue; Liu, Xiaojing
2016-01-01
Urban waterlogging seriously threatens the safety of urban residents and properties. Wargame simulation research on resident emergency evacuation from waterlogged areas can determine the effectiveness of emergency response plans for high risk events at low cost. Based on wargame theory and emergency evacuation plans, we used a wargame exercise method, incorporating qualitative and quantitative aspects, to build an urban waterlogging disaster emergency shelter using a wargame exercise and evaluation model. The simulation was empirically tested in Daoli District of Harbin. The results showed that the wargame simulation scored 96.40 points, evaluated as good. From the simulation results, wargame simulation of urban waterlogging emergency procedures for disaster response can improve the flexibility and capacity for command, management and decision-making in emergency management departments. PMID:28009805
Use of digital control theory state space formalism for feedback at SLC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Himel, T.; Hendrickson, L.; Rouse, F.
The algorithms used in the database-driven SLC fast-feedback system are based on the state space formalism of digital control theory. These are implemented as a set of matrix equations which use a Kalman filter to estimate a vector of states from a vector of measurements, and then apply a gain matrix to determine the actuator settings from the state vector. The matrices used in the calculation are derived offline using Linear Quadratic Gaussian minimization. For a given noise spectrum, this procedure minimizes the rms of the states (e.g., the position or energy of the beam). The offline program also allowsmore » simulation of the loop's response to arbitrary inputs, and calculates its frequency response. 3 refs., 3 figs.« less
Conditioned Reinforcement and Response Strength
Shahan, Timothy A
2010-01-01
Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration. PMID:20885815
Misreading Science in the Twentieth Century.
ERIC Educational Resources Information Center
Budd, John M.
2001-01-01
Considers textual aspects of scientific communication and problems for reception presented by the complex dynamics of communicating scientific work. Discusses scientific work based on fraud or misconduct and disputes about the nature of science, and applies reception theory and reader-response criticism to understand variations in readings of the…
Social Skills Training for Young Adolescents.
ERIC Educational Resources Information Center
Wise, Kathryn L.; And Others
1991-01-01
Six-session systematic assertiveness training program based on social cognitive theory and focusing on peer interactions and social responsibility was presented to 22 sixth graders. Compared to control group, students who received training performed significantly better on test of cognitive acquisition of the information at posttest and six-month…
Dynamical Systems Theory: Application to Pedagogy
NASA Astrophysics Data System (ADS)
Abraham, Jane L.
Theories of learning affect how cognition is viewed, and this subsequently leads to the style of pedagogical practice that is used in education. Traditionally, educators have relied on a variety of theories on which to base pedagogy. Behavioral learning theories influenced the teaching/learning process for over 50 years. In the 1960s, the information processing approach brought the mind back into the learning process. The current emphasis on constructivism integrates the views of Piaget, Vygotsky, and cognitive psychology. Additionally, recent scientific advances have allowed researchers to shift attention to biological processes in cognition. The problem is that these theories do not provide an integrated approach to understanding principles responsible for differences among students in cognitive development and learning ability. Dynamical systems theory offers a unifying theoretical framework to explain the wider context in which learning takes place and the processes involved in individual learning. This paper describes how principles of Dynamic Systems Theory can be applied to cognitive processes of students, the classroom community, motivation to learn, and the teaching/learning dynamic giving educational psychologists a framework for research and pedagogy.
A Multiagent Based Model for Tactical Planning
2002-10-01
Pub. Co. 1985. [10] Castillo, J.M. Aproximación mediante procedimientos de Inteligencia Artificial al planeamiento táctico. Doctoral Thesis...been developed under the same conceptual model and using similar Artificial Intelligence Tools. We use four different stimulus/response agents in...The conceptual model is built on base of the Agents theory. To implement the different agents we have used Artificial Intelligence techniques such
ERIC Educational Resources Information Center
Gao, Rui; He, Wei; Ruan, Chunyi
2012-01-01
In this study, we investigated whether preequating results agree with equating results that are based on observed operational data (postequating) for a college placement program. Specifically, we examined the degree to which item response theory (IRT) true score preequating results agreed with those from IRT true score postequating and from…
NASA Astrophysics Data System (ADS)
Norouzzadeh, A.; Ansari, R.; Rouhi, H.
2017-05-01
Differential form of Eringen's nonlocal elasticity theory is widely employed to capture the small-scale effects on the behavior of nanostructures. However, paradoxical results are obtained via the differential nonlocal constitutive relations in some cases such as in the vibration and bending analysis of cantilevers, and recourse must be made to the integral (original) form of Eringen's theory. Motivated by this consideration, a novel nonlocal formulation is developed herein based on the original formulation of Eringen's theory to study the buckling behavior of nanobeams. The governing equations are derived according to the Timoshenko beam theory, and are represented in a suitable vector-matrix form which is applicable to the finite-element analysis. In addition, an isogeometric analysis (IGA) is conducted for the solution of buckling problem. Construction of exact geometry using non-uniform rational B-splines and easy implementation of geometry refinement tools are the main advantages of IGA. A comparison study is performed between the predictions of integral and differential nonlocal models for nanobeams under different kinds of end conditions.
Bonthuis, Douwe Jan; Netz, Roland R
2013-10-03
Standard continuum theory fails to predict several key experimental results of electrostatic and electrokinetic measurements at aqueous electrolyte interfaces. In order to extend the continuum theory to include the effects of molecular solvent structure, we generalize the equations for electrokinetic transport to incorporate a space dependent dielectric profile, viscosity profile, and non-electrostatic interaction potential. All necessary profiles are extracted from atomistic molecular dynamics (MD) simulations. We show that the MD results for the ion-specific distribution of counterions at charged hydrophilic and hydrophobic interfaces are accurately reproduced using the dielectric profile of pure water and a non-electrostatic repulsion in an extended Poisson-Boltzmann equation. The distributions of Na(+) at both surface types and Cl(-) at hydrophilic surfaces can be modeled using linear dielectric response theory, whereas for Cl(-) at hydrophobic surfaces it is necessary to apply nonlinear response theory. The extended Poisson-Boltzmann equation reproduces the experimental values of the double-layer capacitance for many different carbon-based surfaces. In conjunction with a generalized hydrodynamic theory that accounts for a space dependent viscosity, the model captures the experimentally observed saturation of the electrokinetic mobility as a function of the bare surface charge density and the so-called anomalous double-layer conductivity. The two-scale approach employed here-MD simulations and continuum theory-constitutes a successful modeling scheme, providing basic insight into the molecular origins of the static and kinetic properties of charged surfaces, and allowing quantitative modeling at low computational cost.
Transient Creep of a Composite Lower Crust. 1; Constitutive Theory
NASA Technical Reports Server (NTRS)
Ivins, Erik R.; Sammis, Charles G.
1996-01-01
A composite model is proposed to describe the time-dependent response of the Earth's lower crust. The motivation for such it model is twofold: First, new observations of widespread postseismic deformation indicate that the deep continental crust responds viscoelastically, having both long-and short-term decay times. Second, by any number of observationally based rationales, the lower crust is compositionally and structurally heterogeneous over many length scales. For heterogeneities that have much smaller characteristic lengths than the minimum deformation wavelength of interest, the aggregate rheology can be described by composite media theory. For wavelengths of the order of the thickness of the lower crust (approx. = 25-40 km) and larger, composite theory may be applied to heterogeneities that are smaller than about several hundred meters, or equivalent to the vertical extent of a thick lower crustal mylonitic shear zone. The composite media theory developed here is constructed using both Eshelhy-Mori-Tanaka theory for aligned generalized spheroidal inclusions and a generalized self-consistent method. The inclusions and matrix are considered to be Maxwellian viscoelastic: a rheology that is consistent with past homogeneous models of postseismic stress relaxation. The composite theory presented here introduces a transient response to a suddenly imposed stress field which does not appear in homogeneous Maxwell models. Analytic expressions for the amplitude and duration of the transient and for the effective long-and short-term viscosities of the composite are given which describe the sensitivity to inclusion concentration (phi), to shape, and to ratio of inclusion-to-matrix viscosity (R).
An Impulse Based Substructuring approach for impact analysis and load case simulations
NASA Astrophysics Data System (ADS)
Rixen, Daniel J.; van der Valk, Paul L. C.
2013-12-01
In the present paper we outline the basic theory of assembling substructures for which the dynamics are described as Impulse Response Functions. The assembly procedure computes the time response of a system by evaluating per substructure the convolution product between the Impulse Response Functions and the applied forces, including the interface forces that are computed to satisfy the interface compatibility. We call this approach the Impulse Based Substructuring method since it transposes to the time domain the Frequency Based Substructuring approach. In the Impulse Based Substructuring technique the Impulse Response Functions of the substructures can be gathered either from experimental tests using a hammer impact or from time-integration of numerical submodels. In this paper the implementation of the method is outlined for the case when the impulse responses of the substructures are computed numerically. A simple bar example is shown in order to illustrate the concept. The Impulse Based Substructuring allows fast evaluation of impact response of a structure when the impulse response of its components is known. It can thus be used to efficiently optimize designs of consumer products by including impact behavior at the early stage of the design, but also for performing substructured simulations of complex structures such as offshore wind turbines.
The victorian ethos of evolution.
Schwartz, Scott C
2005-01-01
The Victorian Age was the culmination of changes in the political, social, scientific, theological and cultural spheres throughout Europe. Darwin's newly elaborated evolutionary idea was the pivot for social Darwinism, a theory based on the gradual movement of the species toward greater self-awareness and strength. Shaw described this process in his play Man and Superman. Freud also utilized the concept in his libido theory. Horney interpreted the process as a psychic response to the intense societal pressures to succeed. A linkage of interdependence and progression of these ideas emerges as the world continues to evolve.
Multi-phasic bi-directional chemotactic responses of the growth cone
Naoki, Honda; Nishiyama, Makoto; Togashi, Kazunobu; Igarashi, Yasunobu; Hong, Kyonsoo; Ishii, Shin
2016-01-01
The nerve growth cone is bi-directionally attracted and repelled by the same cue molecules depending on the situations, while other non-neural chemotactic cells usually show uni-directional attraction or repulsion toward their specific cue molecules. However, how the growth cone differs from other non-neural cells remains unclear. Toward this question, we developed a theory for describing chemotactic response based on a mathematical model of intracellular signaling of activator and inhibitor. Our theory was first able to clarify the conditions of attraction and repulsion, which are determined by balance between activator and inhibitor, and the conditions of uni- and bi-directional responses, which are determined by dose-response profiles of activator and inhibitor to the guidance cue. With biologically realistic sigmoidal dose-responses, our model predicted tri-phasic turning response depending on intracellular Ca2+ level, which was then experimentally confirmed by growth cone turning assays and Ca2+ imaging. Furthermore, we took a reverse-engineering analysis to identify balanced regulation between CaMKII (activator) and PP1 (inhibitor) and then the model performance was validated by reproducing turning assays with inhibitions of CaMKII and PP1. Thus, our study implies that the balance between activator and inhibitor underlies the multi-phasic bi-directional turning response of the growth cone. PMID:27808115
Park, In Sook; Suh, Yeon Ok; Park, Hae Sook; Kang, So Young; Kim, Kwang Sung; Kim, Gyung Hee; Choi, Yeon-Hee; Kim, Hyun-Ju
2017-01-01
The purpose of this study was to improve the quality of items on the Korean Nursing Licensing Examination by developing and evaluating case-based items that reflect integrated nursing knowledge. We conducted a cross-sectional observational study to develop new case-based items. The methods for developing test items included expert workshops, brainstorming, and verification of content validity. After a mock examination of undergraduate nursing students using the newly developed case-based items, we evaluated the appropriateness of the items through classical test theory and item response theory. A total of 50 case-based items were developed for the mock examination, and content validity was evaluated. The question items integrated 34 discrete elements of integrated nursing knowledge. The mock examination was taken by 741 baccalaureate students in their fourth year of study at 13 universities. Their average score on the mock examination was 57.4, and the examination showed a reliability of 0.40. According to classical test theory, the average level of item difficulty of the items was 57.4% (80%-100% for 12 items; 60%-80% for 13 items; and less than 60% for 25 items). The mean discrimination index was 0.19, and was above 0.30 for 11 items and 0.20 to 0.29 for 15 items. According to item response theory, the item discrimination parameter (in the logistic model) was none for 10 items (0.00), very low for 20 items (0.01 to 0.34), low for 12 items (0.35 to 0.64), moderate for 6 items (0.65 to 1.34), high for 1 item (1.35 to 1.69), and very high for 1 item (above 1.70). The item difficulty was very easy for 24 items (below -2.0), easy for 8 items (-2.0 to -0.5), medium for 6 items (-0.5 to 0.5), hard for 3 items (0.5 to 2.0), and very hard for 9 items (2.0 or above). The goodness-of-fit test in terms of the 2-parameter item response model between the range of 2.0 to 0.5 revealed that 12 items had an ideal correct answer rate. We surmised that the low reliability of the mock examination was influenced by the timing of the test for the examinees and the inappropriate difficulty of the items. Our study suggested a methodology for the development of future case-based items for the Korean Nursing Licensing Examination.
Log In to Experiential Learning Theory: Supporting Web-Based Faculty Development
Brien, Sarah; Parry, Marcus
2017-01-01
Background For an increasingly busy and geographically dispersed faculty, the Faculty of Medicine at the University of Southampton, United Kingdom, developed a range of Web-based faculty development modules, based on Kolb’s experiential learning cycle, to complement the faculty’s face-to-face workshops. Objective The objective of this study was to assess users’ views and perceptions of the effectiveness of Web-based faculty development modules based on Kolb’s experiential learning cycle. We explored (1) users’ satisfaction with the modules, (2) whether Kolb’s design framework supported users’ learning, and (3) whether the design principle impacts their work as educators. Methods We gathered data from users over a 3-year period using evaluation surveys built into each of the seven modules. Quantitative data were analyzed using descriptive statistics, and responses to open-ended questions were analyzed using content analysis. Results Out of the 409 module users, 283 completed the survey (69.1% response rate). Over 80% of the users reported being satisfied or very satisfied with seven individual aspects of the modules. The findings suggest a strong synergy between the design features that users rated most highly and the key stages of Kolb’s learning cycle. The use of simulations and videos to give the users an initial experience as well as the opportunity to “Have a go” and receive feedback in a safe environment were both considered particularly useful. In addition to providing an opportunity for reflection, many participants considered that the modules would enhance their roles as educators through: increasing their knowledge on various education topics and the required standards for medical training, and improving their skills in teaching and assessing students through practice and feedback and ultimately increasing their confidence. Conclusions Kolb’s theory-based design principle used for Web-based faculty development can support faculty to improve their skills and has impact on their role as educators. Grounding Web-based training in learning theory offers an effective and flexible approach for faculty development. PMID:28954718
NASA Astrophysics Data System (ADS)
Tran Quoc, Tinh; Khong Trong, Toan; Luong Van, Hai
2018-04-01
In this paper, Improved Moving Element Method (IMEM) is used to analyze the dynamic response of Euler-Bernoulli beam structures on the dynamic foundation model subjected to the moving load. The effects of characteristic foundation model parameters such as Winkler stiffness, shear layer based on the Pasternak model, viscoelastic dashpot and characteristic parameter of mass on foundation. Beams are modeled by moving elements while the load is fixed. Based on the principle of the publicly virtual balancing and the theory of moving element method, the motion differential equation of the system is established and solved by means of the numerical integration based on the Newmark algorithm. The influence of mass on foundation and the roughness of the beam surface on the dynamic response of beam are examined in details.
Cultural bases for self-evaluation: seeing oneself positively in different cultural contexts.
Becker, Maja; Vignoles, Vivian L; Owe, Ellinor; Easterbrook, Matthew J; Brown, Rupert; Smith, Peter B; Bond, Michael Harris; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Aldhafri, Said; González, Roberto; Carrasco, Diego; Paz Cadena, Maria; Lay, Siugmin; Schweiger Gallo, Inge; Torres, Ana; Camino, Leoncio; Özgen, Emre; Güner, Ülkü E; Yamakoğlu, Nil; Silveira Lemos, Flávia Cristina; Trujillo, Elvia Vargas; Balanta, Paola; Macapagal, Ma Elizabeth J; Cristina Ferreira, M; Herman, Ginette; de Sauvage, Isabelle; Bourguignon, David; Wang, Qian; Fülöp, Márta; Harb, Charles; Chybicka, Aneta; Mekonnen, Kassahun Habtamu; Martin, Mariana; Nizharadze, George; Gavreliuc, Alin; Buitendach, Johanna; Valk, Aune; Koller, Silvia H
2014-05-01
Several theories propose that self-esteem, or positive self-regard, results from fulfilling the value priorities of one's surrounding culture. Yet, surprisingly little evidence exists for this assertion, and theories differ about whether individuals must personally endorse the value priorities involved. We compared the influence of four bases for self-evaluation (controlling one's life, doing one's duty, benefitting others, achieving social status) among 4,852 adolescents across 20 cultural samples, using an implicit, within-person measurement technique to avoid cultural response biases. Cross-sectional and longitudinal analyses showed that participants generally derived feelings of self-esteem from all four bases, but especially from those that were most consistent with the value priorities of others in their cultural context. Multilevel analyses confirmed that the bases of positive self-regard are sustained collectively: They are predictably moderated by culturally normative values but show little systematic variation with personally endorsed values.
ERIC Educational Resources Information Center
Magno, Carlo
2009-01-01
The present report demonstrates the difference between classical test theory (CTT) and item response theory (IRT) approach using an actual test data for chemistry junior high school students. The CTT and IRT were compared across two samples and two forms of test on their item difficulty, internal consistency, and measurement errors. The specific…
ERIC Educational Resources Information Center
Kohli, Nidhi; Koran, Jennifer; Henn, Lisa
2015-01-01
There are well-defined theoretical differences between the classical test theory (CTT) and item response theory (IRT) frameworks. It is understood that in the CTT framework, person and item statistics are test- and sample-dependent. This is not the perception with IRT. For this reason, the IRT framework is considered to be theoretically superior…
Modelling Trial-by-Trial Changes in the Mismatch Negativity
Lieder, Falk; Daunizeau, Jean; Garrido, Marta I.; Friston, Karl J.; Stephan, Klaas E.
2013-01-01
The mismatch negativity (MMN) is a differential brain response to violations of learned regularities. It has been used to demonstrate that the brain learns the statistical structure of its environment and predicts future sensory inputs. However, the algorithmic nature of these computations and the underlying neurobiological implementation remain controversial. This article introduces a mathematical framework with which competing ideas about the computational quantities indexed by MMN responses can be formalized and tested against single-trial EEG data. This framework was applied to five major theories of the MMN, comparing their ability to explain trial-by-trial changes in MMN amplitude. Three of these theories (predictive coding, model adjustment, and novelty detection) were formalized by linking the MMN to different manifestations of the same computational mechanism: approximate Bayesian inference according to the free-energy principle. We thereby propose a unifying view on three distinct theories of the MMN. The relative plausibility of each theory was assessed against empirical single-trial MMN amplitudes acquired from eight healthy volunteers in a roving oddball experiment. Models based on the free-energy principle provided more plausible explanations of trial-by-trial changes in MMN amplitude than models representing the two more traditional theories (change detection and adaptation). Our results suggest that the MMN reflects approximate Bayesian learning of sensory regularities, and that the MMN-generating process adjusts a probabilistic model of the environment according to prediction errors. PMID:23436989
Beta Regression Finite Mixture Models of Polarization and Priming
ERIC Educational Resources Information Center
Smithson, Michael; Merkle, Edgar C.; Verkuilen, Jay
2011-01-01
This paper describes the application of finite-mixture general linear models based on the beta distribution to modeling response styles, polarization, anchoring, and priming effects in probability judgments. These models, in turn, enhance our capacity for explicitly testing models and theories regarding the aforementioned phenomena. The mixture…
Responsible Student Affairs Practice: Merging Student Development and Quality Management.
ERIC Educational Resources Information Center
Whitner, Phillip A.; And Others
The merging of Total Quality Management (TQM) and Involvement Theory into a managerial philosophy can assist student affairs professionals with an approach for conducting work that improves student affairs practice. When merged or integrated, accountability can easily be obtained because the base philosophies of qualitative research, TQM, and…
IRT Equating of the MCAT. MCAT Monograph.
ERIC Educational Resources Information Center
Hendrickson, Amy B.; Kolen, Michael J.
This study compared various equating models and procedures for a sample of data from the Medical College Admission Test(MCAT), considering how item response theory (IRT) equating results compare with classical equipercentile results and how the results based on use of various IRT models, observed score versus true score, direct versus linked…
Ramsay-Curve Differential Item Functioning
ERIC Educational Resources Information Center
Woods, Carol M.
2011-01-01
Differential item functioning (DIF) occurs when an item on a test, questionnaire, or interview has different measurement properties for one group of people versus another, irrespective of true group-mean differences on the constructs being measured. This article is focused on item response theory based likelihood ratio testing for DIF (IRT-LR or…
Equipping Preservice Elementary Teachers for Data Use in the Classroom
ERIC Educational Resources Information Center
Reeves, Todd D.
2017-01-01
Current preservice teacher education practice related to data use has been deemed inadequate, in that it is unevenly distributed and often superficial. In response, this article describes a course-based classroom assessment data-literacy experience for preservice elementary teachers. Grounded in extant theory and research concerning data literacy…
ERIC Educational Resources Information Center
Yan, Duanli; Lewis, Charles; Stocking, Martha
It is unrealistic to suppose that standard item response theory (IRT) models will be appropriate for all new and currently considered computer-based tests. In addition to developing new models, researchers will need to give some attention to the possibility of constructing and analyzing new tests without the aid of strong models. Computerized…
Stochastic Ordering Using the Latent Trait and the Sum Score in Polytomous IRT Models.
ERIC Educational Resources Information Center
Hemker, Bas T.; Sijtsma, Klaas; Molenaar, Ivo W.; Junker, Brian W.
1997-01-01
Stochastic ordering properties are investigated for a broad class of item response theory (IRT) models for which the monotone likelihood ratio does not hold. A taxonomy is given for nonparametric and parametric models for polytomous models based on the hierarchical relationship between the models. (SLD)
Likelihood-Ratio DIF Testing: Effects of Nonnormality
ERIC Educational Resources Information Center
Woods, Carol M.
2008-01-01
Differential item functioning (DIF) occurs when an item has different measurement properties for members of one group versus another. Likelihood-ratio (LR) tests for DIF based on item response theory (IRT) involve statistically comparing IRT models that vary with respect to their constraints. A simulation study evaluated how violation of the…
Journeying: Children Responding to Literature.
ERIC Educational Resources Information Center
Holland, Kathleen E., Ed.; And Others
Based on Louise Rosenblatt's transactional theory of reader response, the studies collected in this book present findings and recommendations that contribute to the understanding of how children create meaning from stories, how they acquire literacy skills to express that meaning, and what role educators play in these literary processes. The book…
Applying Neurodevelopmental Theory to School-Based Drug Misuse Prevention during Adolescence
ERIC Educational Resources Information Center
Riggs, Nathaniel R.; Black, David S.; Ritt-Olson, Anamara
2014-01-01
Adolescence is characterized by incredible development in the prefrontal cortex of the brain, which is responsible for behavioral and emotional self-regulation, and higher order cognitive decision-making skills (that is, executive function). Typically late prefrontal cortical development and its integration with limbic areas of the brain…
Assessing Equating Results on Different Equating Criteria
ERIC Educational Resources Information Center
Tong, Ye; Kolen, Michael
2005-01-01
The performance of three equating methods--the presmoothed equipercentile method, the item response theory (IRT) true score method, and the IRT observed score method--were examined based on three equating criteria: the same distributions property, the first-order equity property, and the second-order equity property. The magnitude of the…
Alternate Theory Formation by Students.
ERIC Educational Resources Information Center
Hanson, R. Keith
Video tapes of student teachers micro-teaching in a high school biology class were analyzed. Attention was focussed on students' interpretations of data and the teacher's responses to these interpretations. Examples are given of student explanations which teachers find unsatisfactory but which are valid alternatives based on the data available to…
College Men's Meanings of Masculinities and Contextual Influences: Toward a Conceptual Model
ERIC Educational Resources Information Center
Harris, Frank, III
2010-01-01
Based on a grounded theory study involving 68 male undergraduates, a conceptual model of the meanings college men ascribe to masculinities is proposed in this article. The participants equated masculinities with "being respected," "being confident and self-assured," "assuming responsibility," and "embodying physical prowess." Contextual factors…
Sophistic Ethics in the Technical Writing Classroom: Teaching "Nomos," Deliberation, and Action.
ERIC Educational Resources Information Center
Scott, J. Blake
1995-01-01
Claims that teaching ethics is particularly important to technical writing. Outlines a classical, sophistic approach to ethics based on the theories and pedagogies of Protagoras, Gorgias, and Isocrates, which emphasizes the Greek concept of "nomos," internal and external deliberation, and responsible action. Discusses problems and…
Practices of Cooperating Teachers Contributing to a High Quality Field Experience
ERIC Educational Resources Information Center
Lafferty, Karen Elizabeth
2015-01-01
This mixed methods study framed in cognitive apprenticeship theory involved cooperating and preservice teachers from 10 university-based credentialing programs in California. It examined the connection between cooperating teacher practices and preservice teachers' perceptions of a high quality field experience. Survey responses from 146…
A Comparative Study of Moral Development of Korean and British Children.
ERIC Educational Resources Information Center
Baek, Hye-Jeong
2002-01-01
Explores Lawrence Kohlberg's theory of moral development in relation to Korean and British children. Illustrates cultural differences in moral orientations. Notes it was not possible to match responses from Korean children to Kohlberg's manual. Suggests that interpretation of children's moral reasoning should be based on consideration of cultural…
Examining the Reliability of Student Growth Percentiles Using Multidimensional IRT
ERIC Educational Resources Information Center
Monroe, Scott; Cai, Li
2015-01-01
Student growth percentiles (SGPs, Betebenner, 2009) are used to locate a student's current score in a conditional distribution based on the student's past scores. Currently, following Betebenner (2009), quantile regression (QR) is most often used operationally to estimate the SGPs. Alternatively, multidimensional item response theory (MIRT) may…
Communitarian Theory and Community Development in the United States.
ERIC Educational Resources Information Center
Sites, William
1998-01-01
The example of Chicago's Humboldt Park, where there is reluctance to use political action in response to gentrification, shows the limitations of communitarian conceptions of community building, which emphasize self-help and consensus building but fail to acknowledge the need for political articulation of rights-based demands. (SK)
Temperature Sensitivities of Extracellular Enzyme Vmax and Km Across Thermal Environments
NASA Astrophysics Data System (ADS)
Allison, S. D.; Romero-Olivares, A.; Lu, Y.; Taylor, J.; Treseder, K. K.
2017-12-01
The magnitude and direction of carbon cycle feedbacks under climate warming remain uncertain due to insufficient knowledge about the temperature sensitivity of microbial processes in soil. Enzymatic rates could increase at higher temperatures, but this response is determined by multiple parameters that may change over time if soil microbes adapt to warming. We used the Michaelis-Menten relationship, the Arrhenius relationship, and biochemical transition state theory to construct hypotheses about the responses of extracellular enzyme Vmax and Km to temperature. Based on the Arrhenius relationship, we hypothesized that Vmax and Km would show positive temperature sensitivities. For enzymes from warmer environments, we expected to find lower Vmax, Km, and Km temperature sensitivity but higher Vmax temperature sensitivity. We tested these hypotheses with enzymes from isolates of the filamentous fungus Neurospora discreta collected around the globe and from decomposing leaf litter in a warming experiment in Alaskan boreal forest. Vmax and Km of most Neurospora extracellular enzymes were temperature sensitive with average Vmax Q10 ranging from 1.48 to 2.25 and Km Q10 ranging from 0.71 to 2.80. For both Vmax and Km, there was a tendency for the parameter to correlate negatively with its temperature sensitivity, a pattern predicted by biochemical theory. Also in agreement with theory, Vmax and Km were positively correlated for some enzymes. In contrast, there was little support for biochemical theory when comparing Vmax and Km across thermal environments. There was no relationship between temperature sensitivity of Vmax or Km and mean annual temperature of the isolation site for Neurospora strains. There was some evidence for greater Vmax under experimental warming in Alaskan litter, but the temperature sensitivities of Vmax and Km did not vary with warming as expected. We conclude that relationships among Vmax, Km, and temperature are largely consistent with biochemical theory, and our enzyme data should be useful for parameterizing trait-based models of microbial processes. However, theoretical predictions about adaptation to thermal environment were not supported by our data, suggesting that covarying edaphic and ecological factors may play a dominant role in soil enzyme responses to climate warming.
Wu, Jiayuan; Hu, Liren; Zhang, Gaohua; Liang, Qilian; Meng, Qiong; Wan, Chonghua
2016-08-01
This research was designed to develop a nasopharyngeal cancer (NPC) scale based on quality of life (QOL) instruments for cancer patients (QLICP-NA). This scale was developed by using a modular approach and was evaluated by classical test and generalizability theories. Programmed decision procedures and theories on instrument development were applied to create QLICP-NA V2.0. A total of 121 NPC inpatients were assessed using QLICP-NA V2.0 to measure their QOL data from hospital admission until discharge. Scale validity, reliability, and responsiveness were evaluated by correlation, factor, parallel, multi-trait scaling, and t test analyses, as well as by generalizability (G) and decision (D) studies of the generalizability theory. Results of multi-trait scaling, correlation, factor, and parallel analyses indicated that QLICP-NA V2.0 exhibited good construct validity. The significant difference of QOL between the treated and untreated NPC patients indicated a good clinical validity of the questionnaire. The internal consistency (α) and test-retest reliability coefficients (intra-class correlations) of each domain, as well as the overall scale, were all >0.70. Ceiling effects were not found in all domains and most facets, except for common side effects (24.8 %) in the domain of common symptoms and side effects, tumor early symptoms (27.3 %) and therapeutic side effects (23.2 %) in specific domain, whereas floor effects did not exist in each domain/facet. The overall changes in the physical and social domains were significantly different between pre- and post-treatments with a moderate effective size (standard response mean) ranging from 0.21 to 0.27 (p < 0.05), but these changes were not obvious in the other domains, as well as in the overall scale. Scale reliability was further confirmed by G coefficients and index of dependability, with more exact variance components based on generalizability theory. QLICP-NA V2.0 exhibited reasonable degrees of validity, reliability, and responsiveness. However, this scale must be further improved before it can be used as a practical instrument to evaluate the QOL of NPC patients in China.
NASA Astrophysics Data System (ADS)
Wälz, Gero; Kats, Daniel; Usvyat, Denis; Korona, Tatiana; Schütz, Martin
2012-11-01
Linear-response methods, based on the time-dependent variational coupled-cluster or the unitary coupled-cluster model, and truncated at the second order according to the Møller-Plesset partitioning, i.e., the TD-VCC[2] and TD-UCC[2] linear-response methods, are presented and compared. For both of these methods a Hermitian eigenvalue problem has to be solved to obtain excitation energies and state eigenvectors. The excitation energies thus are guaranteed always to be real valued, and the eigenvectors are mutually orthogonal, in contrast to response theories based on “traditional” coupled-cluster models. It turned out that the TD-UCC[2] working equations for excitation energies and polarizabilities are equivalent to those of the second-order algebraic diagrammatic construction scheme ADC(2). Numerical tests are carried out by calculating TD-VCC[2] and TD-UCC[2] excitation energies and frequency-dependent dipole polarizabilities for several test systems and by comparing them to the corresponding values obtained from other second- and higher-order methods. It turns out that the TD-VCC[2] polarizabilities in the frequency regions away from the poles are of a similar accuracy as for other second-order methods, as expected from the perturbative analysis of the TD-VCC[2] polarizability expression. On the other hand, the TD-VCC[2] excitation energies are systematically too low relative to other second-order methods (including TD-UCC[2]). On the basis of these results and an analysis presented in this work, we conjecture that the perturbative expansion of the Jacobian converges more slowly for the TD-VCC formalism than for TD-UCC or for response theories based on traditional coupled-cluster models.
Lei, Pingguang; Lei, Guanghe; Tian, Jianjun; Zhou, Zengfen; Zhao, Miao; Wan, Chonghua
2014-10-01
This paper is aimed to develop the irritable bowel syndrome (IBS) scale of the system of Quality of Life Instruments for Chronic Diseases (QLICD-IBS) by the modular approach and validate it by both classical test theory and generalizability theory. The QLICD-IBS was developed based on programmed decision procedures with multiple nominal and focus group discussions, in-depth interview, and quantitative statistical procedures. One hundred twelve inpatients with IBS were used to provide the data measuring QOL three times before and after treatments. The psychometric properties of the scale were evaluated with respect to validity, reliability, and responsiveness employing correlation analysis, factor analyses, multi-trait scaling analysis, t tests and also G studies and D studies of generalizability theory analysis. Multi-trait scaling analysis, correlation, and factor analyses confirmed good construct validity and criterion-related validity when using SF-36 as a criterion. Test-retest reliability coefficients (Pearson r and intra-class correlation (ICC)) for the overall score and all domains were higher than 0.80; the internal consistency α for all domains at two measurements were higher than 0.70 except for the social domain (0.55 and 0.67, respectively). The overall score and scores for all domains/facets had statistically significant changes after treatments with moderate or higher effect size standardized response mean (SRM) ranging from 0.72 to 1.02 at domain levels. G coefficients and index of dependability (Ф coefficients) confirmed the reliability of the scale further with more exact variance components. The QLICD-IBS has good validity, reliability, responsiveness, and some highlights and can be used as the quality of life instrument for patients with IBS.
Flexoelectricity from density-functional perturbation theory
NASA Astrophysics Data System (ADS)
Stengel, Massimiliano
2013-11-01
We derive the complete flexoelectric tensor, including electronic and lattice-mediated effects, of an arbitrary insulator in terms of the microscopic linear response of the crystal to atomic displacements. The basic ingredient, which can be readily calculated from first principles in the framework of density-functional perturbation theory, is the quantum-mechanical probability current response to a long-wavelength acoustic phonon. Its second-order Taylor expansion in the wave vector q around the Γ (q=0) point in the Brillouin zone naturally yields the flexoelectric tensor. At order one in q we recover Martin's theory of piezoelectricity [Martin, Phys. Rev. B 5, 1607 (1972)], thus providing an alternative derivation thereof. To put our derivations on firm theoretical grounds, we perform a thorough analysis of the nonanalytic behavior of the dynamical matrix and other response functions in a vicinity of Γ. Based on this analysis, we find that there is an ambiguity in the specification of the “zero macroscopic field” condition in the flexoelectric case; such arbitrariness can be related to an analytic band-structure term, in close analogy to the theory of deformation potentials. As a by-product, we derive a rigorous generalization of the Cochran-Cowley formula [Cochran and Cowley, J. Phys. Chem. Solids 23, 447 (1962)] to higher orders in q. This can be of great utility in building reliable atomistic models of electromechanical phenomena, as well as for improving the accuracy of the calculation of phonon dispersion curves. Finally, we discuss the physical interpretation of the various contributions to the flexoelectric response, either in the static or dynamic regime, and we relate our findings to earlier theoretical works on the subject.
Structuring Light to Manipulate Multipolar Resonances for Metamaterial Applications
NASA Astrophysics Data System (ADS)
Das, Tanya
Multipolar electromagnetic phenomena in sub-wavelength resonators are at the heart of metamaterial science and technology. Typically, researchers engineer multipolar light-matter interactions by modifying the size, shape, and composition of the resonators. Here, we instead engineer multipolar interactions by modifying properties of the incident radiation. In this dissertation, we propose a new framework for determining the scattering response of resonators based on properties of the local excitation field. First, we derive an analytical theory to determine the scattering response of spherical nanoparticles under any type of illumination. Using this theory, we demonstrate the ability to drastically manipulate the scattering properties of a spherical nanoparticle by varying the illumination and demonstrate excitation of a longitudinal quadrupole mode that cannot be accessed with conventional illumination. Next, we investigate the response of dielectric dimer structures illuminated by cylindrical vector beams. Using finite-difference time-domain simulations, we demonstrate significant modification of the scattering spectra of dimer antennas and reveal how the illumination condition gives rise to these spectra through manipulation of electric and magnetic mode hybridization. Finally, we present a simple and efficient numerical simulation based on local field principles for extracting the multipolar response of any resonator under illumination by structured light. This dissertation enhances the understanding of fundamental light-matter interactions in metamaterials and lays the foundation for researchers to identify, quantify, and manipulate multipolar light-matter interactions through optical beam engineering.
NASA Astrophysics Data System (ADS)
Song, Y.; Yao, Q.; Wang, G.; Yang, X.; Mayes, M. A.
2017-12-01
Increasing evidences is indicating that soil organic matter (SOM) decomposition and stabilization process is a continuum process and controlled by both microbial functions and their interaction with minerals (known as the microbial efficiency-matrix stabilization theory (MEMS)). Our metagenomics analysis of soil samples from both P-deficit and P-fertilization sites in Panama has demonstrated that community-level enzyme functions could adapt to maximize the acquisition of limiting nutrients and minimize energy demand for foraging (known as the optimal foraging theory). This optimization scheme can mitigate the imbalance of C/P ratio between soil substrate and microbial community and relieve the P limitation on microbial carbon use efficiency over the time. Dynamic allocation of multiple enzyme groups and their interaction with microbial/substrate stoichiometry has rarely been considered in biogeochemical models due to the difficulties in identifying microbial functional groups and quantifying the change in enzyme expression in response to soil nutrient availability. This study aims to represent the omics-informed optimal foraging theory in the Continuum Microbial ENzyme Decomposition model (CoMEND), which was developed to represent the continuum SOM decomposition process following the MEMS theory. The SOM pools in the model are classified based on soil chemical composition (i.e. Carbohydrates, lignin, N-rich SOM and P-rich SOM) and the degree of SOM depolymerization. The enzyme functional groups for decomposition of each SOM pool and N/P mineralization are identified by the relative composition of gene copy numbers. The responses of microbial activities and SOM decomposition to nutrient availability are simulated by optimizing the allocation of enzyme functional groups following the optimal foraging theory. The modeled dynamic enzyme allocation in response to P availability is evaluated by the metagenomics data measured from P addition and P-deficit soil samples in Panama sites.The implementation of dynamic enzyme allocation in response to nutrient availability in the CoMEND model enables us to capture the varying microbial C/P ratio and soil carbon dynamics in response to shifting nutrient constraints over time in tropical soils.
Analytical theory of polymer-network-mediated interaction between colloidal particles
Di Michele, Lorenzo; Zaccone, Alessio; Eiser, Erika
2012-01-01
Nanostructured materials based on colloidal particles embedded in a polymer network are used in a variety of applications ranging from nanocomposite rubbers to organic-inorganic hybrid solar cells. Further, polymer-network-mediated colloidal interactions are highly relevant to biological studies whereby polymer hydrogels are commonly employed to probe the mechanical response of living cells, which can determine their biological function in physiological environments. The performance of nanomaterials crucially relies upon the spatial organization of the colloidal particles within the polymer network that depends, in turn, on the effective interactions between the particles in the medium. Existing models based on nonlocal equilibrium thermodynamics fail to clarify the nature of these interactions, precluding the way toward the rational design of polymer-composite materials. In this article, we present a predictive analytical theory of these interactions based on a coarse-grained model for polymer networks. We apply the theory to the case of colloids partially embedded in cross-linked polymer substrates and clarify the origin of attractive interactions recently observed experimentally. Monte Carlo simulation results that quantitatively confirm the theoretical predictions are also presented. PMID:22679289
NASA Astrophysics Data System (ADS)
Yang, J.; Zhang, H.; Wang, C.; Tang, D.
2018-04-01
With the continuous development of social economy, the interaction between mankind and nature has become increasingly evident. Disastrous global catastrophes have occurred from time to time, causing huge losses to people's lives and property. All governments recognize the importance of the establishment of disaster early warning and release mechanisms, and it is also an urgent issue to improve the comprehensive service level of emergency response and disaster relief. However, disaster early warning and emergency relief information is usually generated by different departments, and the diverse data sources, difficult integration, and limited release speed have always been difficult issues to be solved. Block data is the aggregation of various distributed (point data) and segmentation (data) big data on a specific platform and make them happen continuous polymerization effect, block data theory is a good solution to cross-sectoral, cross-platform Disaster information data sharing and integration problems. This paper attempts to discuss the integrated service mechanism of disaster information aggregation and disaster relief based on block data theory and introduces a location-based integrated service system for disaster early warning and disaster relief.
NASA Astrophysics Data System (ADS)
Paatz, Roland; Ryder, James; Schwedes, Hannelore; Scott, Philip
2004-09-01
The purpose of this case study is to analyse the learning processes of a 16-year-old student as she learns about simple electric circuits in response to an analogy-based teaching sequence. Analogical thinking processes are modelled by a sequence of four steps according to Gentner's structure mapping theory (activate base domain, postulate local matches, connect them to a global match, draw candidate inferences). We consider whether Gentner's theory can be used to account for the details of this specific teaching/learning context. The case study involved video-taping teaching and learning activities in a 10th-grade high school course in Germany. Teaching used water flow through pipes as an analogy for electrical circuits. Using Gentner's theory, relational nets were created from the student's statements at different stages of her learning. Overall, these nets reflect the four steps outlined earlier. We also consider to what extent the learning processes revealed by this case study are different from previous analyses of contexts in which no analogical knowledge is available.
Goldenberg, Amit; Halperin, Eran; van Zomeren, Martijn; Gross, James J
2016-05-01
Scholars interested in emotion regulation have documented the different goals and strategies individuals have for regulating their emotions. However, little attention has been paid to the regulation of group-based emotions, which are based on individuals' self-categorization as a group member and occur in response to situations perceived as relevant for that group. We propose a model for examining group-based emotion regulation that integrates intergroup emotions theory and the process model of emotion regulation. This synergy expands intergroup emotion theory by facilitating further investigation of different goals (i.e., hedonic or instrumental) and strategies (e.g., situation selection and modification strategies) used to regulate group-based emotions. It also expands emotion regulation research by emphasizing the role of self-categorization (e.g., as an individual or a group member) in the emotional process. Finally, we discuss the promise of this theoretical synergy and suggest several directions for future research on group-based emotion regulation. © 2015 by the Society for Personality and Social Psychology, Inc.
Variability in Reward Responsivity and Obesity: Evidence from Brain Imaging Studies
Burger, Kyle S.; Stice, Eric
2012-01-01
Advances in neuroimaging techniques have provided insight into the role of the brain in the regulation of food intake and weight. Growing evidence demonstrate that energy dense, palatable foods elicit similar responses in reward-related brain regions that mimic those of addictive substances. Currently, various models of obesity’s relation to reward from food have been theorized. There is evidence to support a theory of hypo-responsivity of reward regions to food, where individuals consume excess amounts to overcome this reward deficit. There is also data to support a theory of hyper-responsivity of reward regions, where individuals who experience greater reward from food intake are at risk for overeating. However, these seemingly discordant theories are static in nature and do not account for the possible effects of repeated overeating on brain responsivity to food and initial vulnerability factors. Here we review data that support these theories and propose a dynamic vulnerability model of obesity that appears to offer a parsimonious theory that accommodates extant findings. PMID:21999692
Chatzisarantis, Nikos L D; Kee, Ying Hwa; Thaung, Hannah Kyaw; Hagger, Martin S
2012-12-01
Based on the tenets of self-determination theory, the present studies examined the moderating effects of interpersonal contexts or goal conditions that afforded satisfaction of psychological needs on loss aversion effects. We hypothesized that behavioural responses to small losses would be stronger relative to behavioural responses to small gains under goal conditions or interpersonal contexts that did not support psychological needs. We also expected the effect to be minimized under goal conditions or interpersonal contexts that supported psychological needs. This prediction was supported in Study 1 that induced satisfaction of psychological needs via manipulations of interpersonal context and in Study 2 that instigated satisfaction of psychological needs via manipulations of goal contents. In addition, Studies 1 and 2 demonstrated that psychological needs reduced the classic loss aversion effect by increasing behavioural and affective responses to gains and not because psychological needs altered affective or behavioural responses to losses. Results of the present studies support the conclusion that contextual autonomy support and the distinction between intrinsic and extrinsic goals proposed by self-determination theory define a boundary condition of the loss aversion hypothesis. ©2011 The British Psychological Society.
NASA Astrophysics Data System (ADS)
Bünemann, Jörg; Seibold, Götz
2017-12-01
Pump-probe experiments have turned out as a powerful tool in order to study the dynamics of competing orders in a large variety of materials. The corresponding analysis of the data often relies on standard linear-response theory generalized to nonequilibrium situations. Here we examine the validity of such an approach for the charge and pairing response of systems with charge-density wave and (or) superconducting (SC) order. Our investigations are based on the attractive Hubbard model which we study within the time-dependent Hartree-Fock approximation. In particular, we calculate the quench and pump-probe dynamics for SC and charge order parameters in order to analyze the frequency spectra and the coupling of the probe field to the specific excitations. Our calculations reveal that the "linear-response assumption" is justified for small to moderate nonequilibrium situations (i.e., pump pulses) in the case of a purely charge-ordered ground state. However, the pump-probe dynamics on top of a superconducting ground state is determined by phase and amplitude modes which get coupled far from the equilibrium state indicating the failure of the linear-response assumption.
Modeling of a piezoelectric/piezomagnetic nano energy harvester based on two dimensional theory
NASA Astrophysics Data System (ADS)
Yan, Zhi
2018-01-01
This work presents a two dimensional theory for a piezoelectric/piezomagnetic bilayer nanoplate in coupled extensional and flexural vibrations with both flexoelectric and surface effects. The magneto-electro-elastic (MEE) coupling equations are derived from three-dimensional equations and Kirchhoff plate theory. Based on the developed theory, a piezoelectric/piezomagnetic nano energy harvester is proposed, which can generate electricity under time-harmonic applied magnetic field. The approximate solutions for the mechanical responses and voltage of the energy harvester are obtained using the weighted residual method. Results show that the properties of the proposed energy harvester are size-dependent due to the flexoelectric and surface effects, and such effects are more pronounced when the bilayer thickness is reduced to dozens of nanometers. It is also found that the magnetoelectric coupling coefficient and power density of the energy harvester are sensitive to the load resistance, the thickness fraction of the piezoelectric or the piezomagnetic layer and damping ratios. Moreover, results indicate that the flexoelectric effect could be made use to build a dielectric/piezomagnetic nano energy harvester. This work provides modeling techniques and numerical methods for investigating the size-dependent properties of MEE nanoplate-based energy harvester and could be helpful for designing nano energy harvesters using the principle of flexoelectricity.
NASA Technical Reports Server (NTRS)
Dillard, D. A.; Morris, D. H.; Brinson, H. F.
1981-01-01
An incremental numerical procedure based on lamination theory is developed to predict creep and creep rupture of general laminates. Existing unidirectional creep compliance and delayed failure data is used to develop analytical models for lamina response. The compliance model is based on a procedure proposed by Findley which incorporates the power law for creep into a nonlinear constitutive relationship. The matrix octahedral shear stress is assumed to control the stress interaction effect. A modified superposition principle is used to account for the varying stress level effect on the creep strain. The lamina failure model is based on a modification of the Tsai-Hill theory which includes the time dependent creep rupture strength. A linear cumulative damage law is used to monitor the remaining lifetime in each ply.
Real time polymer nanocomposites-based physical nanosensors: theory and modeling.
Bellucci, Stefano; Shunin, Yuri; Gopeyenko, Victor; Lobanova-Shunina, Tamara; Burlutskaya, Nataly; Zhukovskii, Yuri
2017-09-01
Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences.
Real time polymer nanocomposites-based physical nanosensors: theory and modeling
NASA Astrophysics Data System (ADS)
Bellucci, Stefano; Shunin, Yuri; Gopeyenko, Victor; Lobanova-Shunina, Tamara; Burlutskaya, Nataly; Zhukovskii, Yuri
2017-09-01
Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences.
Ibn al-Haytham (965-1039 AD), the original portrayal of the modern theory of vision.
Daneshfard, Babak; Dalfardi, Behnam; Nezhad, Golnoush Sadat Mahmoudi
2016-05-01
Abū ՙAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham, known in the West as Alhazen, was an Arab-Islamic scholar who helped develop the science of ophthalmology during the medieval era. He was the first to reject firmly the extramission theory of vision, which was prevalent during his time, and suggested that the eyes are the source of the light rays responsible for vision. Ibn al-Haytham in his book entitled Kitab al-Manazir (Book of Optics) explained vision based on light emanating from objects. In this study we review Ibn al-Haytham's life and introduce his major contribution to the field of ophthalmology, his theory of vision. © IMechE 2014.
Modern control techniques in active flutter suppression using a control moment gyro
NASA Technical Reports Server (NTRS)
Buchek, P. M.
1974-01-01
Development of organized synthesis techniques, using concepts of modern control theory was studied for the design of active flutter suppression systems for two and three-dimensional lifting surfaces, utilizing a control moment gyro (CMG) to generate the required control torques. Incompressible flow theory is assumed, with the unsteady aerodynamic forces and moments for arbitrary airfoil motion obtained by using the convolution integral based on Wagner's indicial lift function. Linear optimal control theory is applied to find particular optimal sets of gain values which minimize a quadratic performance function. The closed loop system's response to impulsive gust disturbances and the resulting control power requirements are investigated, and the system eigenvalues necessary to minimize the maximum value of control power are determined.
Minimal entropy approximation for cellular automata
NASA Astrophysics Data System (ADS)
Fukś, Henryk
2014-02-01
We present a method for the construction of approximate orbits of measures under the action of cellular automata which is complementary to the local structure theory. The local structure theory is based on the idea of Bayesian extension, that is, construction of a probability measure consistent with given block probabilities and maximizing entropy. If instead of maximizing entropy one minimizes it, one can develop another method for the construction of approximate orbits, at the heart of which is the iteration of finite-dimensional maps, called minimal entropy maps. We present numerical evidence that the minimal entropy approximation sometimes outperforms the local structure theory in characterizing the properties of cellular automata. The density response curve for elementary CA rule 26 is used to illustrate this claim.
Aeroelastic equations of motion of a Darrieus vertical-axis wind-turbine blade
NASA Technical Reports Server (NTRS)
Kaza, K. R. V.; Kvaternik, R. G.
1979-01-01
The second-degree nonlinear aeroelastic equations of motion for a slender, flexible, nonuniform, Darrieus vertical-axis wind turbine blade which is undergoing combined flatwise bending, edgewise bending, torsion, and extension are developed using Hamilton's principle. The blade aerodynamic loading is obtained from strip theory based on a quasi-steady approximation of two-dimensional incompressible unsteady airfoil theory. The derivation of the equations has its basis in the geometric nonlinear theory of elasticity and the resulting equations are consistent with the small deformation approximation in which the elongations and shears are negligible compared to unity. These equations are suitable for studying vibrations, static and dynamic aeroelastic instabilities, and dynamic response. Several possible methods of solution of the equations, which have periodic coefficients, are discussed.
The social reality of the imaginary audience: a grounded theory approach.
Bell, Joanna H; Bromnick, Rachel D
2003-01-01
Traditional approaches to understanding the imaginary audience are challenged in this study. Three hundred sixty-one British schoolchildren (aged 14 and 15 years) were asked to express their worries and concerns, using grounded theory methodology. Qualitative responses were collated and coded according to emerging categories, with "what other people think" identified as the central concern. In particular, the findings are used to critique Elkind's (1967) theory of adolescent egocentrism. Data presented in this study suggest that adolescents worry about what other people think because there are real personal and social consequences. Such concerns are seen as being based in social reality and are not imaginary as Elkind suggested. In conclusion, new methodologies which place young people at the center of the analysis are advocated.
NASA Astrophysics Data System (ADS)
Marco-Pallarés, Josep; Mas-Herrero, Ernest
2015-06-01
The study of emotions has been an important topic in cognitive and affective neuroscience in the last decades. In the present manuscript, Koelsch et al. [1] propose a new neurobiological framework based on four emotional core systems (the Quartet), involved in different aspects of human emotion processing. This is an interesting theory that goes beyond classical emotion classification to describe the emotional experience based on four main cerebral components (brainstem, diencephalon, hippocampus, and orbitofrontal cortex). This approach allows the description of different classes of affects, including those that are unique in humans as emotional responses associated to abstract stimuli (for example, aesthetical stimuli such as art and music).
Cappelleri, Joseph C.; Lundy, J. Jason; Hays, Ron D.
2014-01-01
Introduction The U.S. Food and Drug Administration’s patient-reported outcome (PRO) guidance document defines content validity as “the extent to which the instrument measures the concept of interest” (FDA, 2009, p. 12). “Construct validity is now generally viewed as a unifying form of validity for psychological measurements, subsuming both content and criterion validity” (Strauss & Smith, 2009, p. 7). Hence both qualitative and quantitative information are essential in evaluating the validity of measures. Methods We review classical test theory and item response theory approaches to evaluating PRO measures including frequency of responses to each category of the items in a multi-item scale, the distribution of scale scores, floor and ceiling effects, the relationship between item response options and the total score, and the extent to which hypothesized “difficulty” (severity) order of items is represented by observed responses. Conclusion Classical test theory and item response theory can be useful in providing a quantitative assessment of items and scales during the content validity phase of patient-reported outcome measures. Depending on the particular type of measure and the specific circumstances, either one or both approaches should be considered to help maximize the content validity of PRO measures. PMID:24811753
A Mixed Multi-Field Finite Element Formulation for Thermopiezoelectric Composite Shells
NASA Technical Reports Server (NTRS)
Lee, Ho-Jun; Saravanos, Dimitris A.
1999-01-01
Analytical formulations are presented which account for the coupled mechanical, electrical, and thermal response of piezoelectric composite shell structures. A new mixed multi-field laminate theory is developed which combines "single layer" assumptions for the displacements along with layerwise fields for the electric potential and temperature. This laminate theory is formulated using curvilinear coordinates and is based on the principles of linear thermopiezoelectricity. The mechanics have the inherent capability to explicitly model both the active and sensory responses of piezoelectric composite shells in thermal environment. Finite element equations are derived and implemented for an eight-noded shell element. Numerical studies are conducted to investigate both the sensory and active responses of piezoelectric composite shell structures subjected to thermal loads. Results for a cantilevered plate with an attached piezoelectric layer are com- pared with corresponding results from a commercial finite element code and a previously developed program. Additional studies are conducted on a cylindrical shell with an attached piezoelectric layer to demonstrate capabilities to achieve thermal shape control on curved piezoelectric structures.
Pupillary response to complex interdependent tasks: A cognitive-load theory perspective.
Mitra, Ritayan; McNeal, Karen S; Bondell, Howard D
2017-10-01
Pupil dilation is known to indicate cognitive load. In this study, we looked at the average pupillary responses of a cohort of 29 undergraduate students during graphical problem solving. Three questions were asked, based on the same graphical input. The questions were interdependent and comprised multiple steps. We propose a novel way of analyzing pupillometry data for such tasks on the basis of eye fixations, a commonly used eyetracking parameter. We found that pupil diameter increased during the solution process. However, pupil diameter did not always reflect the expected cognitive load. This result was studied within a cognitive-load theory model. Higher-performing students showed evidence of germane load and schema creation, indicating use of the interdependent nature of the tasks to inform their problem-solving process. However, lower-performing students did not recognize the interdependent nature of the tasks and solved each problem independently, which was expressed in a markedly different pupillary response pattern. We discuss the import of our findings for instructional design.
Perales, José C; Catena, Andrés; Shanks, David R; González, José A
2005-09-01
A number of studies using trial-by-trial learning tasks have shown that judgments of covariation between a cue c and an outcome o deviate from normative metrics. Parameters based on trial-by-trial predictions were estimated from signal detection theory (SDT) in a standard causal learning task. Results showed that manipulations of P(c) when contingency (deltaP) was held constant did not affect participants' ability to predict the appearance of the outcome (d') but had a significant effect on response criterion (c) and numerical causal judgments. The association between criterion c and judgment was further demonstrated in 2 experiments in which the criterion was directly manipulated by linking payoffs to the predictive responses made by learners. In all cases, the more liberal the criterion c was, the higher judgments were. The results imply that the mechanisms underlying the elaboration of judgments and those involved in the elaboration of predictive responses are partially dissociable.
Temperature Effects of Dielectric Properties of ER Fluids
NASA Astrophysics Data System (ADS)
Qiu, Z. Y.; Hu, L.; Liu, M. W.; Bao, H. X.; Jiang, Y. G.; Zhou, L. W.; Tang, Y.; Gao, Z.; Sun, M.; Korobko, E. V.
Under the consideration of the role that energy transfer and dissipation play in ER effect, an improved theory frame for ER effects, polarization-dissipation-structure-rheology, is suggested. The theory frame is substantiated by the basic physical laws and certain critical experimental facts. The dielectric response of a diatomite ER fluid to temperature is measured in the temperature range of 140 K to 400 K. By comparison of the DC conductivity with the AC effective conductivity of the sample, we found that the AC dielectric loss consists of two parts. One part comes from the DC conductivity, the other from the response of the bound charges in scope of particle to AC field. It is suggested that the response of bound charges is very important to ER effects. Besides, the effect of temperature on shear stress is measured, and interpreted based on the dielectric measurements. The source of two loss peaks in the curve of the dielectric loss versus temperature is not clear.
Bayesian Estimation of Multi-Unidimensional Graded Response IRT Models
ERIC Educational Resources Information Center
Kuo, Tzu-Chun
2015-01-01
Item response theory (IRT) has gained an increasing popularity in large-scale educational and psychological testing situations because of its theoretical advantages over classical test theory. Unidimensional graded response models (GRMs) are useful when polytomous response items are designed to measure a unified latent trait. They are limited in…
Shen, Minxue; Cui, Yuanwu; Hu, Ming; Xu, Linyong
2017-01-13
The study aimed to validate a scale to assess the severity of "Yin deficiency, intestine heat" pattern of functional constipation based on the modern test theory. Pooled longitudinal data of 237 patients with "Yin deficiency, intestine heat" pattern of constipation from a prospective cohort study were used to validate the scale. Exploratory factor analysis was used to examine the common factors of items. A multidimensional item response model was used to assess the scale with the presence of multidimensionality. The Cronbach's alpha ranged from 0.79 to 0.89, and the split-half reliability ranged from 0.67 to 0.79 at different measurements. Exploratory factor analysis identified two common factors, and all items had cross factor loadings. Bidimensional model had better goodness of fit than the unidimensional model. Multidimensional item response model showed that the all items had moderate to high discrimination parameters. Parameters indicated that the first latent trait signified intestine heat, while the second trait characterized Yin deficiency. Information function showed that items demonstrated highest discrimination power among patients with moderate to high level of disease severity. Multidimensional item response theory provides a useful and rational approach in validating scales for assessing the severity of patterns in traditional Chinese medicine.
Development of the Contact Lens User Experience: CLUE Scales
Wirth, R. J.; Edwards, Michael C.; Henderson, Michael; Henderson, Terri; Olivares, Giovanna; Houts, Carrie R.
2016-01-01
ABSTRACT Purpose The field of optometry has become increasingly interested in patient-reported outcomes, reflecting a common trend occurring across the spectrum of healthcare. This article reviews the development of the Contact Lens User Experience: CLUE system designed to assess patient evaluations of contact lenses. CLUE was built using modern psychometric methods such as factor analysis and item response theory. Methods The qualitative process through which relevant domains were identified is outlined as well as the process of creating initial item banks. Psychometric analyses were conducted on the initial item banks and refinements were made to the domains and items. Following this data-driven refinement phase, a second round of data was collected to further refine the items and obtain final item response theory item parameters estimates. Results Extensive qualitative work identified three key areas patients consider important when describing their experience with contact lenses. Based on item content and psychometric dimensionality assessments, the developing CLUE instruments were ultimately focused around four domains: comfort, vision, handling, and packaging. Item response theory parameters were estimated for the CLUE item banks (377 items), and the resulting scales were found to provide precise and reliable assignment of scores detailing users’ subjective experiences with contact lenses. Conclusions The CLUE family of instruments, as it currently exists, exhibits excellent psychometric properties. PMID:27383257
Culturally Responsive Teaching in the Context of Mathematics: A Grounded Theory Case Study
ERIC Educational Resources Information Center
Bonner, Emily P.; Adams, Thomasenia L.
2012-01-01
In this grounded theory case study, four interconnected, foundational cornerstones of culturally responsive mathematics teaching (CRMT), communication, knowledge, trust/relationships, and constant reflection/revision, were systematically unearthed to develop an initial working theory of CRMT that directly informs classroom practice. These…
NASA Astrophysics Data System (ADS)
Stalbaum, Tyler; Shen, Qi; Kim, Kwang J.
2017-04-01
Ionic polymer-metal composite (IPMC) is a promising material for soft-robotic actuator and sensor applications. This material system offers large deformation response for low input voltage and has an aptitude for operation in hydrated environments. Researchers have been developing IPMC actuators and sensors for applications with examples of self-sensing actuators, artificial fish fins and biomimicry of other aquatic lifeforms, and in medical operations such as in guided catheter devices. IPMCs have been developed in a range of geometric configurations, with tube or cylindrical and flat-plate rectangular as the most common shapes. Several mathematical and physics-based models have been developed for describing the transduction effects of IPMCs. In this work, the underlying theories of electromechanical and mechanoelectrical transduction in IPMCs are discussed, and simulated results of frequency response and shear response are presented. A model backbone is utilized which is primarily based on ion-transport and charge dynamics within the polymer membrane. The electromechanical model, that is with an IPMC as an actuator, is caused when an electric field is applied across the membrane causing ionic migration and swelling in the polymer membrane, which is based on the Poisson-Nernst-Planck equations and solid mechanics models. The mechanoelectric model is similar in underlying physics; however, the primary mechanisms of transduction are of different significance, where anion concentrations are as important as cations. COMSOL Multiphysics is utilized for simulations. Example applications of the modeling framework are presented. The simulated results provide additional support for the underlying physics theories discussed.
An ecological valence theory of human color preference
Palmer, Stephen E.; Schloss, Karen B.
2010-01-01
Color preference is an important aspect of visual experience, but little is known about why people in general like some colors more than others. Previous research suggested explanations based on biological adaptations [Hurlbert AC, Ling YL (2007) Curr Biol 17:623–625] and color-emotions [Ou L-C, Luo MR, Woodcock A, Wright A (2004) Color Res Appl 29:381–389]. In this article we articulate an ecological valence theory in which color preferences arise from people’s average affective responses to color-associated objects. An empirical test provides strong support for this theory: People like colors strongly associated with objects they like (e.g., blues with clear skies and clean water) and dislike colors strongly associated with objects they dislike (e.g., browns with feces and rotten food). Relative to alternative theories, the ecological valence theory both fits the data better (even with fewer free parameters) and provides a more plausible, comprehensive causal explanation of color preferences. PMID:20421475
Linear response theory for annealing of radiation damage in semiconductor devices
NASA Technical Reports Server (NTRS)
Litovchenko, Vitaly
1988-01-01
A theoretical study of the radiation/annealing response of MOS ICs is described. Although many experiments have been performed in this field, no comprehensive theory dealing with radiation/annealing response has been proposed. Many attempts have been made to apply linear response theory, but no theoretical foundation has been presented. The linear response theory outlined here is capable of describing a broad area of radiation/annealing response phenomena in MOS ICs, in particular, both simultaneous irradiation and annealing, as well as short- and long-term annealing, including the case when annealing is nearing completion. For the first time, a simple procedure is devised to determine the response function from experimental radiation/annealing data. In addition, this procedure enables us to study the effect of variable temperature and dose rate, effects which are of interest in spaceflight. In the past, the shift in threshold potential due to radiation/annealing has usually been assumed to depend on one variable: the time lapse between an impulse dose and the time of observation. While such a suggestion of uniformity in time is certainly true for a broad range of radiation annealing phenomena, it may not hold for some ranges of the variables of interest (temperature, dose rate, etc.). A response function is projected which is dependent on two variables: the time of observation and the time of the impulse dose. This dependence on two variables allows us to extend the theory to the treatment of a variable dose rate. Finally, the linear theory is generalized to the case in which the response is nonlinear with impulse dose, but is proportional to some impulse function of dose. A method to determine both the impulse and response functions is presented.
[Behavioral phenotypes: cognitive and emotional explanation].
Pérez-Alvarez, F; Timoneda-Gallart, C
We present a series of Behavioural phenotypes treated with neurocognitive and neuroemotional procedure. A sample of 26 cases were selected according to qualitative methodology from neuropediatric patients. The method was based on using the PASS theory of intelligence to approach the cognitive problem and the theory of masquerade behaviour as self-defence to solve the emotional problem. Both theories have neurological bases. DN:CAS battery was utilized for assessment of cognitive processes. On the other hand, analysis of cases was carried out doing data analysis with video recorder device. All cases were considered responder cases although in different degree. The responder was defined as the patient which reached better intellectual achievement with respect to cognitive function and which gave up, at least partially, masquerade Behaviour with respect to emotional function. The Behaviour of the Behavioural phenotypes has neurological rationale. The PASS theory and the planning, in particular, supported by prefrontal cortex justifies consistently some behaviours. The masquerade Behaviour theory is explained by the fear emotional response mechanism which means emotion is a cerebral processing with neurological rationale. The Behavioural phenotypes are Behaviours and every Behaviour can be explained by neurological reasons both cognitive and emotional reasons. So, they can be treated by a cognitive and emotional procedure understood in the light of the neurology.
An introduction to Item Response Theory and Rasch Analysis of the Eating Assessment Tool (EAT-10).
Kean, Jacob; Brodke, Darrel S; Biber, Joshua; Gross, Paul
2018-03-01
Item response theory has its origins in educational measurement and is now commonly applied in health-related measurement of latent traits, such as function and symptoms. This application is due in large part to gains in the precision of measurement attributable to item response theory and corresponding decreases in response burden, study costs, and study duration. The purpose of this paper is twofold: introduce basic concepts of item response theory and demonstrate this analytic approach in a worked example, a Rasch model (1PL) analysis of the Eating Assessment Tool (EAT-10), a commonly used measure for oropharyngeal dysphagia. The results of the analysis were largely concordant with previous studies of the EAT-10 and illustrate for brain impairment clinicians and researchers how IRT analysis can yield greater precision of measurement.
Kelava, Augustin; Muma, Michael; Deja, Marlene; Dagdagan, Jack Y.; Zoubir, Abdelhak M.
2015-01-01
Emotion eliciting situations are accompanied by changes of multiple variables associated with subjective, physiological and behavioral responses. The quantification of the overall simultaneous synchrony of psychophysiological reactions plays a major role in emotion theories and has received increased attention in recent years. From a psychometric perspective, the reactions represent multivariate non-stationary intra-individual time series. In this paper, a new time-frequency based latent variable approach for the quantification of the synchrony of the responses is presented. The approach is applied to empirical data, collected during an emotion eliciting situation. The results are compared with a complementary inter-individual approach of Hsieh et al. (2011). Finally, the proposed approach is discussed in the context of emotion theories, and possible future applications and limitations are provided. PMID:25653624
Torsional vibration of a pipe pile in transversely isotropic saturated soil
NASA Astrophysics Data System (ADS)
Zheng, Changjie; Hua, Jianmin; Ding, Xuanming
2016-09-01
This study considers the torsional vibration of a pipe pile in a transversely isotropic saturated soil layer. Based on Biot's poroelastic theory and the constitutive relations of the transversely isotropic medium, the dynamic governing equations of the outer and inner transversely isotropic saturated soil layers are derived. The Laplace transform is used to solve the governing equations of the outer and inner soil layers. The dynamic torsional response of the pipe pile in the frequency domain is derived utilizing 1D elastic theory and the continuous conditions at the interfaces between the pipe pile and the soils. The time domain solution is obtained by Fourier inverse transform. A parametric study is conducted to demonstrate the influence of the anisotropies of the outer and inner soil on the torsional dynamic response of the pipe pile.