WorldWideScience

Sample records for theory irt-based approaches

  1. Measuring individual significant change on the Beck Depression Inventory-II through IRT-based statistics

    NARCIS (Netherlands)

    Brouwer, Danny; Meijer, Rob; Zevalkink, J.

    2013-01-01

    Several researchers have emphasized that item response theory (IRT)-based methods should be preferred over classical approaches in measuring change for individual patients. In the present study we discuss and evaluate the use of IRT-based statistics to measure statistical significant individual

  2. Comparing countdown- and IRT-based approaches to computerized adaptive personality testing.

    Science.gov (United States)

    Rudick, Monica M; Yam, Wern How; Simms, Leonard J

    2013-09-01

    Computerized adaptive testing (CAT) is an emerging technology in the personality assessment literature given the greater efficiency it affords compared with traditional methods. However, few studies have directly compared the efficiency and validity of 2 competing methods for personality CAT: (a) methods based on item response theory (IRT-CAT) versus (b) methods based on the countdown method (CM-CAT). To that end, we conducted real-data simulations with previously collected responses (N = 8,690) to the Schedule for Nonadaptive and Adaptive Personality (SNAP). Three CAT algorithms (IRT-CAT, IRT-CAT with 5-item minimum, CM-CAT) were evaluated for item savings, classification accuracy, and convergent/discriminant validity. All CATs yielded lower classification accuracy and validity than traditional testing but required 18%-86% fewer items. Ultimately, the IRT-CAT, with minimum 5-item requirement, struck the most ideal balance of highest item savings, and generally fewer costs to validity and accuracy. These results confirm findings regarding item savings trends from previous CAT studies. In addition, this study provides a model for how the validity and precision of CATs may be compared across personality assessments.

  3. A new IRT-based standard setting method: application to eCat-listening.

    Science.gov (United States)

    García, Pablo Eduardo; Abad, Francisco José; Olea, Julio; Aguado, David

    2013-01-01

    Criterion-referenced interpretations of tests are highly necessary, which usually involves the difficult task of establishing cut scores. Contrasting with other Item Response Theory (IRT)-based standard setting methods, a non-judgmental approach is proposed in this study, in which Item Characteristic Curve (ICC) transformations lead to the final cut scores. eCat-Listening, a computerized adaptive test for the evaluation of English Listening, was administered to 1,576 participants, and the proposed standard setting method was applied to classify them into the performance standards of the Common European Framework of Reference for Languages (CEFR). The results showed a classification closely related to relevant external measures of the English language domain, according to the CEFR. It is concluded that the proposed method is a practical and valid standard setting alternative for IRT-based tests interpretations.

  4. Empirical vs. Expected IRT-Based Reliability Estimation in Computerized Multistage Testing (MST)

    Science.gov (United States)

    Zhang, Yanwei; Breithaupt, Krista; Tessema, Aster; Chuah, David

    2006-01-01

    Two IRT-based procedures to estimate test reliability for a certification exam that used both adaptive (via a MST model) and non-adaptive design were considered in this study. Both procedures rely on calibrated item parameters to estimate error variance. In terms of score variance, one procedure (Method 1) uses the empirical ability distribution…

  5. The Relationship between CTT and IRT Approaches in Analyzing Item Characteristics

    Science.gov (United States)

    Abedalaziz, Nabeel; Leng, Chin Hai

    2013-01-01

    Most of the tests and inventories used by counseling psychologists have been developed using CTT; IRT derives from what is called latent trait theory. A number of important differences exist between CTT- versus IRT-based approaches to both test development and evaluation, as well as the process of scoring the response profiles of individual…

  6. plink: An R Package for Linking Mixed-Format Tests Using IRT-Based Methods

    Directory of Open Access Journals (Sweden)

    Jonathan P. Weeks

    2010-10-01

    Full Text Available The R package plink has been developed to facilitate the linking of mixed-format tests for multiple groups under a common item design using unidimensional and multidimensional IRT-based methods. This paper presents the capabilities of the package in the context of the unidimensional methods. The package supports nine unidimensional item response models (the Rasch model, 1PL, 2PL, 3PL, graded response model, partial credit and generalized partial credit model, nominal response model, and multiple-choice model and four separate calibration linking methods (mean/sigma, mean/mean, Haebara, and Stocking-Lord. It also includes functions for importing item and/or ability parameters from common IRT software, conducting IRT true-score and observed-score equating, and plotting item response curves and parameter comparison plots.

  7. Examining Differential Item Functioning: IRT-Based Detection in the Framework of Confirmatory Factor Analysis

    Science.gov (United States)

    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.

  8. Location theory a unified approach

    CERN Document Server

    Nickel, Stefan

    2006-01-01

    Although modern location theory is now more than 90 years old, the focus of researchers in this area has been mainly problem oriented. However, a common theory, which keeps the essential characteristics of classical location models, is still missing.This monograph addresses this issue. A flexible location problem called the Ordered Median Problem (OMP) is introduced. For all three main subareas of location theory (continuous, network and discrete location) structural properties of the OMP are presented and solution approaches provided. Numerous illustrations and examples help the reader to bec

  9. The suitability of the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA) as a screening tool: IRT-based evidence.

    Science.gov (United States)

    Chiesi, Francesca; Donati, Maria Anna; Galli, Silvia; Primi, Caterina

    2013-03-01

    The South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA) is one of the most widely used measures of adolescent gambling. We aimed to provide evidence of its suitability as a screening tool applying item response theory (IRT). The scale was administered to 981 adolescents (64% males; mean age = 16.57 years, SD = 1.63 years) attending high school. Analyses were carried out with a sample of 871 respondents, that is, adolescents who have gambled at least once during the previous year. Once the prerequisite of unidimensionality was confirmed through confirmatory factor analysis, unidimensional IRT analyses were performed. The 2-parameter logistic model was used in order to estimate item parameters (severity and discrimination) and the test information function. Results showed that item severity ranged from medium to high, and most of the items showed large discrimination parameters, indicating that the scale accurately measures medium to high levels of problem gambling. These regions of the trait were associated with the greatest amount of information, indicating that the SOGS-RA provides a reliable measure for identifying both problem gamblers and adolescents at risk of developing maladaptive behaviors deriving from gambling. The IRT-based evidence supports the suitability of the SOGS-RA as a screening tool in adolescent populations. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  10. Theories and theorizers: a contextual approach to theories of cognition.

    Science.gov (United States)

    Barutta, Joaquín; Cornejo, Carlos; Ibáñez, Agustín

    2011-06-01

    An undisputable characteristic of cognitive science is its enormous diversity of theories. Not surprisingly, these often belong to different paradigms that focus on different processes and levels of analysis. A related problem is that researchers of cognition frequently seem to ascribe to incompatible approaches to research, creating a Tower of Babel of cognitive knowledge. This text presents a pragmatic model of meta-theoretical analysis, a theory conceived of to examine other theories, which allows cognitive theories to be described, integrated and compared. After a brief introduction to meta-theoretical analysis in cognitive science, the dynamic and structural components of a theory are described. The analysis of conceptual mappings between components and explanation strategies is also described, as well as the processes of intra-theory generalization and inter-theory comparison. The various components of the meta-theoretical model are presented with examples of different cognitive theories, mainly focusing on two current approaches to research: The dynamical approach to cognition and the computer metaphor of mind. Finally, two potential counter arguments to the model are presented and discussed.

  11. Equilibrium theory : A salient approach

    NARCIS (Netherlands)

    Schalk, S.

    1999-01-01

    Whereas the neoclassical models in General Equilibrium Theory focus on the existence of separate commodities, this thesis regards 'bundles of trade' as the unit objects of exchange. Apart from commodities and commodity bundles in the neoclassical sense, the term `bundle of trade' includes, for

  12. Decision theory principles and approaches

    CERN Document Server

    Parmigiani, Giovanni

    2009-01-01

    Decision theory provides a formal framework for making logical choices in the face of uncertainty. Given a set of alternatives, a set of consequences, and a correspondence between those sets, decision theory offers conceptually simple procedures for choice. This book presents an overview of the fundamental concepts and outcomes of rational decision making under uncertainty, highlighting the implications for statistical practice. The authors have developed a series of self contained chapters focusing on bridging the gaps between the different fields that have contributed to rational decision making and presenting ideas in a unified framework and notation while respecting and highlighting the different and sometimes conflicting perspectives. This book: Provides a rich collection of techniques and procedures.Discusses the foundational aspects and modern day practice.Links foundations to practical applications in biostatistics, computer science, engineering and economics.Presents different perspectives and cont...

  13. Quantum theory a mathematical approach

    CERN Document Server

    Bongaarts, Peter

    2015-01-01

    This book was inspired by the general observation that the great theories of modern physics are based on simple and transparent underlying mathematical structures – a fact not usually emphasized in standard physics textbooks – which makes it easy for mathematicians to understand their basic features. It is a textbook on quantum theory intended for advanced undergraduate or graduate students: mathematics students interested in modern physics, and physics students who are interested in the mathematical background of physics and are dissatisfied with the level of rigor in standard physics courses. More generally, it offers a valuable resource for all mathematicians interested in modern physics, and all physicists looking for a higher degree of mathematical precision with regard to the basic concepts in their field.

  14. A philosophical approach to quantum field theory

    CERN Document Server

    Öttinger, Hans Christian

    2017-01-01

    This text presents an intuitive and robust mathematical image of fundamental particle physics based on a novel approach to quantum field theory, which is guided by four carefully motivated metaphysical postulates. In particular, the book explores a dissipative approach to quantum field theory, which is illustrated for scalar field theory and quantum electrodynamics, and proposes an attractive explanation of the Planck scale in quantum gravity. Offering a radically new perspective on this topic, the book focuses on the conceptual foundations of quantum field theory and ontological questions. It also suggests a new stochastic simulation technique in quantum field theory which is complementary to existing ones. Encouraging rigor in a field containing many mathematical subtleties and pitfalls this text is a helpful companion for students of physics and philosophers interested in quantum field theory, and it allows readers to gain an intuitive rather than a formal understanding.

  15. Interpreting quantum theory a therapeutic approach

    CERN Document Server

    Friederich, S

    2014-01-01

    Is it possible to approach quantum theory in a 'therapeutic' vein that sees its foundational problems as arising from mistaken conceptual presuppositions? The book explores the prospects for this project and, in doing so, discusses such fascinating issues as the nature of quantum states, explanation in quantum theory, and 'quantum non-locality'.

  16. Variational approach in transport theory

    Energy Technology Data Exchange (ETDEWEB)

    Panta Pazos, R. [Nucler Engineering Department, UFRGS, Porto-Alegre (Brazil); Tullio de Vilhena, M. [Institute of Mathematics, UFRGS, Porto-Alegre (Brazil)

    2004-07-01

    In this work we present a variational approach to some methods to solve transport problems of neutral particles. We consider a convex domain X (for example the geometry of a slab, or a convex set in the plane, or a convex bounded set in the space) and we use discrete ordinates quadrature to get a system of differential equations derived from the neutron transport equation. The boundary conditions are vacuum for a subset of the boundary, and of specular reflection for the complementary subset of the boundary. Recently some different approximation methods have been presented to solve these transport problems. We introduce in this work the adjoint equations and the conjugate functions obtained by means of the variational approach. First we consider the general formulation, and then some numerical methods such as spherical harmonics and spectral collocation method. (authors)

  17. Systems Theory and Systems Approach to Leadership

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Berim Ramosaj

    2014-06-01

    Full Text Available Systems theory is product of the efforts of many researchers to create an intermediate field of coexistence of all sciences. If not for anything else, because of the magnitude that the use of systemic thinking and systemic approach has taken, it has become undisputed among the theories. Systems theory not only provides a glossary of terms with which researchers from different fields can be understood, but provides a framework for the presentation and interpretation of phenomena and realities. This paper addresses a systematic approach to leadership, as an attempt to dredge leadership and systems theory literature to find the meeting point. Systems approach is not an approach to leadership in terms of a manner of leader’s work, but it’s the leader's determination to factorize in his leadership the external environment and relationships with and among elements. Leader without followers is unable to exercise his leadership and to ensure their conviction he should provide a system, a structure, a purpose, despite the alternative chaos. Systems approach clarifies the thought on the complexity and dynamism of the environment and provides a framework for building ideas. If the general system theory is the skeleton of science (Boulding: 1956, this article aims to replenish it with leadership muscles by prominent authors who have written on systems theory and leadership, as well as through original ideas. In this work analytical methods were used (by analyzing approaches individually as well as synthetic methods (by assaying individual approaches in context of entirety. The work is a critical review of literature as well as a deductive analysis mingled with models proposed by authors through inductive analysis. Meta-analysis has been used to dissect the interaction and interdependence between leadership approaches.

  18. Algebra and Number Theory An Integrated Approach

    CERN Document Server

    Dixon, Martyn; Subbotin, Igor

    2011-01-01

    Explore the main algebraic structures and number systems that play a central role across the field of mathematics Algebra and number theory are two powerful branches of modern mathematics at the forefront of current mathematical research, and each plays an increasingly significant role in different branches of mathematics, from geometry and topology to computing and communications. Based on the authors' extensive experience within the field, Algebra and Number Theory has an innovative approach that integrates three disciplines-linear algebra, abstract algebra, and number theory-into one compr

  19. Interacting electrons theory and computational approaches

    CERN Document Server

    Martin, Richard M; Ceperley, David M

    2016-01-01

    Recent progress in the theory and computation of electronic structure is bringing an unprecedented level of capability for research. Many-body methods are becoming essential tools vital for quantitative calculations and understanding materials phenomena in physics, chemistry, materials science and other fields. This book provides a unified exposition of the most-used tools: many-body perturbation theory, dynamical mean field theory and quantum Monte Carlo simulations. Each topic is introduced with a less technical overview for a broad readership, followed by in-depth descriptions and mathematical formulation. Practical guidelines, illustrations and exercises are chosen to enable readers to appreciate the complementary approaches, their relationships, and the advantages and disadvantages of each method. This book is designed for graduate students and researchers who want to use and understand these advanced computational tools, get a broad overview, and acquire a basis for participating in new developments.

  20. Renormalization group approach to density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Kemler, Sandra; Braun, Jens [Institut fuer Kernphysik, TU Darmstadt (Germany)

    2015-07-01

    We study a two-point particle irreducible (2PPI) approach to many-body physics which relies on a renormalization group (RG) flow equation for the associated effective action. This approach relates to Density Functional Theory and can in principle be used to study ground-state properties of non-relativistic many-body systems from microscopic interactions, such as (heavy) nuclei. We apply our formalism to a 0+1-dimensional model, namely the quantum anharmonic oscillator and use the well-known exact solution to benchmark our approximations of the full RG flow. Moreover, we present flow equations for specific types of 1+1-dimensional field theories which allow us study the ground-state properties of self-bound systems of spinless fermions which can also be viewed as toy models of nuclei.

  1. A statistical mechanics approach to Granovetter theory

    CERN Document Server

    Barra, Adriano

    2010-01-01

    In this paper we try to bridge breakthroughs in quantitative sociology/econometrics pioneered during the last decades by Mac Fadden, Brock-Durlauf, Granovetter and Watts-Strogats through introducing a minimal model able to reproduce essentially all the features of social behavior highlighted by these authors. Our model relies on a pairwise Hamiltonian for decision maker interactions which naturally extends the multi-populations approaches by shifting and biasing the pattern definitions of an Hopfield model of neural networks. Once introduced, the model is investigated trough graph theory (to recover Granovetter and Watts-Strogats results) and statistical mechanics (to recover Mac-Fadden and Brock-Durlauf results). Due to internal symmetries of our model, the latter is obtained as the relaxation of a proper Markov process, allowing even to study its out of equilibrium properties. The method used to solve its equilibrium is an adaptation of the Hamilton-Jacobi technique recently introduced by Guerra in the spin...

  2. IRT-Based Measurement of Short-Term Changes of Ability, with an Application to Assessing the "Mozart Effect"

    Science.gov (United States)

    Gittler, Georg; Fischer, Gerhard

    2011-01-01

    The article extends and applies previous approaches by Klauer and Fischer to the statistical evaluation of ability changes in tests conforming to the Rasch model (RM). Exact uniformly most powerful unbiased (UMPU) hypothesis tests and uniformly most accurate (UMA) confidence intervals (CIs) for the amount of change can be constructed for each…

  3. Practical theology: A critically engaged practical reason approach of practice, theory, practice and theory

    OpenAIRE

    John S. Klaasen

    2014-01-01

    Browning’s influential use of practical reason for his fundamental practical theology is analysed. His correlation of theory and practice in his three stages of theory, practice and theory is also critiqued because his approach reduces practical theology almost to professionalism and principles for ministry. His approach could also result in an antagonistic relationship between practice and theory as practice is reduced to theory or academics. This article seeks to present a critically engage...

  4. Effective theory approach to direct detection of dark matter

    OpenAIRE

    Hisano, Junji

    2017-01-01

    An effective field theory approach is presented for evaluation of the dark matter direct detection rate in this lecture note. This is prepared for the Les Houches Summer School Effective Field Theory in Particle Physics and Cosmology, July 2017.

  5. Interpreting Quantum Theory : A Therapeutic Approach

    NARCIS (Netherlands)

    Friederich, Simon

    2014-01-01

    Debates about the foundations of quantum theory usually circle around two main challenges: the so-called 'measurement problem' and a claimed tension between quantum theory and relativity theory that arises from the phenomena labelled 'quantum non-locality'. This work explores the possibility of a

  6. Boolean Approach to Dichotomic Quantum Measurement Theories

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, K. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Nakamura, T. [Keio University, Yokohama (Japan); Batle, J. [Universitat de les Illes Balears, Balearic Islands (Spain); Abdalla, S. [King Abdulaziz University Jeddah, Jeddah (Saudi Arabia); Farouk, A. [Al-Zahra College for Women, Muscat (Egypt)

    2017-02-15

    Recently, a new measurement theory based on truth values was proposed by Nagata and Nakamura [Int. J. Theor. Phys. 55, 3616 (2016)], that is, a theory where the results of measurements are either 0 or 1. The standard measurement theory accepts a hidden variable model for a single Pauli observable. Hence, we can introduce a classical probability space for the measurement theory in this particular case. Additionally, we discuss in the present contribution the fact that projective measurement theories (the results of which are either +1 or −1) imply the Bell, Kochen, and Specker (BKS) paradox for a single Pauli observable. To justify our assertion, we present the BKS theorem in almost all the two-dimensional states by using a projective measurement theory. As an example, we present the BKS theorem in two-dimensions with white noise. Our discussion provides new insight into the quantum measurement problem by using this measurement theory based on the truth values.

  7. Effective field theory approaches for tensor potentials

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Maximilian

    2016-11-14

    Effective field theories are a widely used tool to study physical systems at low energies. We apply them to systematically analyze two and three particles interacting via tensor potentials. Two examples are addressed: pion interactions for anti D{sup 0}D{sup *0} scattering to dynamically generate the X(3872) and dipole interactions for two and three bosons at low energies. For the former, the one-pion exchange and for the latter, the long-range dipole force induce a tensor-like structure of the potential. We apply perturbative as well as non-perturbative methods to determine low-energy observables. The X(3872) is of major interest in modern high-energy physics. Its exotic characteristics require approaches outside the range of the quark model for baryons and mesons. Effective field theories represent such methods and provide access to its peculiar nature. We interpret the X(3872) as a hadronic molecule consisting of neutral D and D{sup *} mesons. It is possible to apply an effective field theory with perturbative pions. Within this framework, we address chiral as well as finite volume extrapolations for low-energy observables, such as the binding energy and the scattering length. We show that the two-point correlation function for the D{sup *0} meson has to be resummed to cure infrared divergences. Moreover, next-to-leading order coupling constants, which were introduced by power counting arguments, appear to be essential to renormalize the scattering amplitude. The binding energy as well as the scattering length display a moderate dependence on the light quark masses. The X(3872) is most likely deeper bound for large light quark masses. In a finite volume on the other hand, the binding energy significantly increases. The dependence on the light quark masses and the volume size can be simultaneously obtained. For bosonic dipoles we apply a non-perturbative, numerical approach. We solve the Lippmann-Schwinger equation for the two-dipole system and the Faddeev

  8. Validating the 28-tender joint count using item response theory

    NARCIS (Netherlands)

    Tjin-Kam-Jet-Siemons, Liseth; ten Klooster, Peter M.; Taal, Erik; Kuper, I.H.; van Riel, Piet L.C.M.; van de Laar, Mart A F J; Glas, Cornelis A.W.

    2011-01-01

    Objective: To examine the construct validity of the 28-tender joint count (TJC-28) using item response theory (IRT)-based methods. Methods: A total of 457 patients with early stage rheumatoid arthritis (RA) were included. Internal construct validity of the TJC-28 was evaluated by determining whether

  9. A statistical mechanics approach to Granovetter theory

    Science.gov (United States)

    Barra, Adriano; Agliari, Elena

    2012-05-01

    In this paper we try to bridge breakthroughs in quantitative sociology/econometrics, pioneered during the last decades by Mac Fadden, Brock-Durlauf, Granovetter and Watts-Strogatz, by introducing a minimal model able to reproduce essentially all the features of social behavior highlighted by these authors. Our model relies on a pairwise Hamiltonian for decision-maker interactions which naturally extends the multi-populations approaches by shifting and biasing the pattern definitions of a Hopfield model of neural networks. Once introduced, the model is investigated through graph theory (to recover Granovetter and Watts-Strogatz results) and statistical mechanics (to recover Mac-Fadden and Brock-Durlauf results). Due to the internal symmetries of our model, the latter is obtained as the relaxation of a proper Markov process, allowing even to study its out-of-equilibrium properties. The method used to solve its equilibrium is an adaptation of the Hamilton-Jacobi technique recently introduced by Guerra in the spin-glass scenario and the picture obtained is the following: shifting the patterns from [-1,+1]→[0.+1] implies that the larger the amount of similarities among decision makers, the stronger their relative influence, and this is enough to explain both the different role of strong and weak ties in the social network as well as its small-world properties. As a result, imitative interaction strengths seem essentially a robust request (enough to break the gauge symmetry in the couplings), furthermore, this naturally leads to a discrete choice modelization when dealing with the external influences and to imitative behavior à la Curie-Weiss as the one introduced by Brock and Durlauf.

  10. A Simple Approach to Complexity Theory

    Science.gov (United States)

    Sanger, Michael; Giddings, Martha M.

    2012-01-01

    This teaching note presents 7 basic ideas that are drawn from complexity theory. These ideas are designed to help students appreciate and work with the complex systems that they often face in practice. Although complexity theory may be presented using mathematical language not easily accessible to non-mathematicians, it also may be presented by…

  11. Grounded theory approach in sermon analysis of sermons on ...

    African Journals Online (AJOL)

    In this article, I am going to discuss the place of grounded theory in qualitative research and the application of Charmaz's approach to it in homiletics. The process of sermon analysis in its different phases will be discussed as well as the interaction of this bottom-up theory with existing homiletic theories in relation to the ...

  12. Variational Wigner-Kirkwood approach to relativistic mean field theory

    Energy Technology Data Exchange (ETDEWEB)

    Del Estal, M.; Centelles, M.; Vinas, X. [Departament d`Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)

    1997-10-01

    The recently developed variational Wigner-Kirkwood approach is extended to the relativistic mean field theory for finite nuclei. A numerical application to the calculation of the surface energy coefficient in semi-infinite nuclear matter is presented. The new method is contrasted with the standard density functional theory and the fully quantal approach. {copyright} {ital 1997} {ital The American Physical Society}

  13. Attachment theory: Old and new approach

    Directory of Open Access Journals (Sweden)

    Polovina Nada

    2005-01-01

    Full Text Available The article is an attempt to present holistically the key concepts of attachment theory rediscovered for its potentials. The presented concepts include: narrow definition of attachment, behavioral control system of attachment, attachment working model and patterns of attachment. The concepts are presented in the context of child attachment theory and adult attachment theory, in addition to description of the development of attachment. Concepts, as well as developmental processes are presented from the stand point of pioneers in this field (John Bowlby and Mary Ainsworth as well as from the standpoint of their successors (Everett Waters and Malcolm West. Compacted ness of the theory, possibilities for operationalization of its key concepts and its application to empirical studies of complex psychological issues that have never been scientifically explored, makes it a very prospective theory in view of possible integration of existing research findings and initiating new research and new practices in psychotherapy, social work and work in schools. The goal of this integral presentation of attachment theory is to highlight its benefits and possibilities for understanding and research complex field of human's psychosocial functioning.

  14. Item response theory - A first approach

    Science.gov (United States)

    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.

  15. An activity theory approach to affordance

    DEFF Research Database (Denmark)

    Bærentsen, Klaus B.; Trettvik, J.

    2002-01-01

    the notion. Specifically we will suggest the inclusion of the ecological theory of perception in the paradigm of cultural historical psychology and activity theory developed in the former Soviet Union by most notably Lev Vygotsky, S. L. Rubinshtein, A. N. Leontjev and others. It will be suggested, that much......We present an analysis of the concept of affordance as it was originally introduced by J. J. Gibson, and elaborate on this concept, acknowledging, that the general theoretical landscape in psychology is in fundamental ways different from the situation in which Gibson found himself when he crafted...

  16. Field theory a path integral approach

    CERN Document Server

    Das, Ashok

    2006-01-01

    This unique book describes quantum field theory completely within the context of path integrals. With its utility in a variety of fields in physics, the subject matter is primarily developed within the context of quantum mechanics before going into specialized areas.Adding new material keenly requested by readers, this second edition is an important expansion of the popular first edition. Two extra chapters cover path integral quantization of gauge theories and anomalies, and a new section extends the supersymmetry chapter, where singular potentials in supersymmetric systems are described.

  17. Constructing New Theory for Identifying Students with Emotional Disturbance: A Constructivist Approach to Grounded Theory

    OpenAIRE

    Dori Barnett

    2012-01-01

    A grounded theory study that examined how practitioners in a county alternative and correctional education setting identify youth with emotional and behavioral difficulties for special education services provides an exemplar for a constructivist approach to grounded theory methodology. Discussion focuses on how a constructivist orientation to grounded theory methodology informed research decisions, shaped the development of the emergent grounded theory, and prompted a way of thinking about da...

  18. Dobrushin's approach to queueing network theory

    Directory of Open Access Journals (Sweden)

    F. I. Karpelevich

    1996-01-01

    Full Text Available R.L. Dobrushin (1929-1995 made substantial contributions to Queueing Network Theory (QNT. A review of results from QNT which arose from his ideas or were connected to him in other ways is given. We also comment on various related open problems.

  19. Anthropological Theory: A Modular Approach. Cultural Anthropology.

    Science.gov (United States)

    Kassebaum, Peter

    Designed for use as supplementary instructional material in a cultural anthropology course, this learning module introduces the student to various theoretical perspectives, terms, and influential figures within the field of anthropology. The following historical and conceptual influences on anthropological theory are discussed: (1) the Greek…

  20. FDI theories. A location-based approach

    Directory of Open Access Journals (Sweden)

    Popovici, Oana Cristina

    2014-09-01

    Full Text Available Given the importance of FDI for the economic growth of both home and host countries, the aim of this paper is to assess the importance granted to location advantages during the development of FDI theory. We start with the earliest theoretical directions as regards FDI location issues and extend our study to describing less debated theories, but of a particular importance for this theme. In this way, we have the opportunity to emphasize the changes in FDI location determinants. We find that a direction of the FDI theories’ expansion is due to the incorporation of new variables on location, although the location advantages are barely mentioned in the first explanations regarding the international activity of the firms.

  1. Information theory based approaches to cellular signaling.

    Science.gov (United States)

    Waltermann, Christian; Klipp, Edda

    2011-10-01

    Cells interact with their environment and they have to react adequately to internal and external changes such changes in nutrient composition, physical properties like temperature or osmolarity and other stresses. More specifically, they must be able to evaluate whether the external change is significant or just in the range of noise. Based on multiple external parameters they have to compute an optimal response. Cellular signaling pathways are considered as the major means of information perception and transmission in cells. Here, we review different attempts to quantify information processing on the level of individual cells. We refer to Shannon entropy, mutual information, and informal measures of signaling pathway cross-talk and specificity. Information theory in systems biology has been successfully applied to identification of optimal pathway structures, mutual information and entropy as system response in sensitivity analysis, and quantification of input and output information. While the study of information transmission within the framework of information theory in technical systems is an advanced field with high impact in engineering and telecommunication, its application to biological objects and processes is still restricted to specific fields such as neuroscience, structural and molecular biology. However, in systems biology dealing with a holistic understanding of biochemical systems and cellular signaling only recently a number of examples for the application of information theory have emerged. This article is part of a Special Issue entitled Systems Biology of Microorganisms. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Comprehensive Review on Divisible Load Theory: Concepts, Strategies, and Approaches

    Directory of Open Access Journals (Sweden)

    Shamsollah Ghanbari

    2014-01-01

    Full Text Available There is extensive literature concerning the divisible load theory. The divisible load theory is mainly applied for scheduling in the area of distributed computing. It is based on the fact that the load can be divided into some arbitrarily independent parts, in which each part can be processed independently by a processor. This paper reviews the literature concerning the divisible load theory, while focusing on the details of the basic concepts, approaches, strategies, typologies, and open problems.

  3. Field theory approaches to new media practices

    DEFF Research Database (Denmark)

    Hartley, Jannie Møller; Willig, Ida; Waltorp, Karen

    2015-01-01

    In this article introducing the theme of the special issue we argue that studies of new media practices might benefit from especially Pierre Bourdieu’s research on cultural production. We introduce some of the literature, which deals with the use of digital media, and which have taken steps...... on more studies within a field theory framework, as the ability of the comprehensive theoretical work and the ideas of a reflexive sociology is able to trigger the good questions, more than it claims to offer a complete and self-sufficient sociology of media and inherent here also new media....

  4. Elementary number theory an algebraic approach

    CERN Document Server

    Bolker, Ethan D

    2007-01-01

    This text uses the concepts usually taught in the first semester of a modern abstract algebra course to illuminate classical number theory: theorems on primitive roots, quadratic Diophantine equations, and the Fermat conjecture for exponents three and four. The text contains abundant numerical examples and a particularly helpful collection of exercises, many of which are small research problems requiring substantial study or outside reading. Some problems call for new proofs for theorems already covered or for inductive explorations and proofs of theorems found in later chapters.Ethan D. Bolke

  5. Modular headache theory: a new approach.

    Science.gov (United States)

    Young, William B

    2002-03-01

    Many people experience headaches that do not fulfill the International Headache Society's criteria for a specific headache disorder, yet behave biologically like that disorder. Others fulfill criteria for one headache disorder but have features of another. To explain these observations, we propose that groups of neurons, called modules, become activated to produce each symptom of a primary headache disorder, and that each module is linked to other modules that together produce an individual's headache. Headaches develop phenotypic stability through a process referred to as learned stereotypy. This theory has implications for the classification, research, and treatment of primary and secondary headache patients.

  6. Workspace and sensorimotor theories : Complementary approaches to experience

    NARCIS (Netherlands)

    Degenaar, J.; Keijzer, F.

    A serious difficulty for theories of consciousness is to go beyond mere correlation between physical processes and experience. Currently, neural workspace and sensorimotor contingency theories are two of the most promising approaches to make any headway here. This paper explores the relation between

  7. Application of grounded theory approach in the analysis of ...

    African Journals Online (AJOL)

    This study examined the application of grounded theory in analyzing integrated primary health care (IPHC) in KwaZulu-Natal province. A description of the similarities and differences between the two approaches to grounded theory research, namely the Glaserian (after Barney Glaser) and the Straussian (after Anselm ...

  8. Evolutionary Theories in Environmental and Resource Economics: Approaches and Applications

    NARCIS (Netherlands)

    van den Bergh, J.C.J.M.; Gowdy, J.M.

    2000-01-01

    Recent advances in evolutionary theory have important implications for environmental economics. A short overview is offered of evolutionary thinking in economics. Subsequently, major concepts and approaches in evolutionary biology and evolutionary economics are presented and compared. Attention is

  9. Decision theory and choices a complexity approach

    CERN Document Server

    Kirman, Alan; Vinci, Concetto Paolo

    2010-01-01

    In economics agents are assumed to choose on the basis of rational calculations aimed at the maximization of their pleasure or profit. Formally, agents are said to manifest transitive and consistent preferences in attempting to maximize their utility in the presence of several constraints. They operate according to the choice imperative: given a set of alternatives, choose the best. This imperative works well in a static and simplistic framework, but it may fail or vary when 'the best' is changing continuously. This approach has been questioned by a descriptive approach that springing from the

  10. Structure and Measurement of Depression in Youths: Applying Item Response Theory to Clinical Data

    Science.gov (United States)

    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

    2011-01-01

    Our goals in this article 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 3,403 children and adolescents…

  11. Further simplification of the simplified erosion narrowing score with item response theory methodology

    NARCIS (Netherlands)

    Oude Voshaar, Antonius H.; Schenk, Olga; ten Klooster, Peter M.; Vonkeman, Harald Erwin; Bernelot Moens, Hein J.; Boers, Maarten; van de Laar, Mart A F J

    Objective: To further simplify the Simple Erosion Narrowing Score (SENS) by removing scored areas that contribute least to its measurement precision according to Item Response Theory (IRT) based analysis and to compare the measurement performance of the simplified version to the original. Methods:

  12. Practical theology: A critically engaged practical reason approach of practice, theory, practice and theory

    Directory of Open Access Journals (Sweden)

    John S. Klaasen

    2014-02-01

    Full Text Available Browning’s influential use of practical reason for his fundamental practical theology is analysed. His correlation of theory and practice in his three stages of theory, practice and theory is also critiqued because his approach reduces practical theology almost to professionalism and principles for ministry. His approach could also result in an antagonistic relationship between practice and theory as practice is reduced to theory or academics. This article seeks to present a critically engaged practical reasoning approach in which theory and practice have an in-ter-dependent relationship. Practical reason is an activity in which engagement happens at every stage. For this to happen, theory and practice interact as equal variables that have a bearing on each other not to reduce the one to the other, but to complement each other in a lateral hermeneutical process. This process has four stages, unlike Browning’s three-stage correlation. The stages are schematically presented as practice, theory, practice and theory.

  13. A renewal theory approach to IBD sharing.

    Science.gov (United States)

    Carmi, Shai; Wilton, Peter R; Wakeley, John; Pe'er, Itsik

    2014-11-01

    A long genomic segment inherited by a pair of individuals from a single, recent common ancestor is said to be identical-by-descent (IBD). Shared IBD segments have numerous applications in genetics, from demographic inference to phasing, imputation, pedigree reconstruction, and disease mapping. Here, we provide a theoretical analysis of IBD sharing under Markovian approximations of the coalescent with recombination. We describe a general framework for the IBD process along the chromosome under the Markovian models (SMC/SMC'), as well as introduce and justify a new model, which we term the renewal approximation, under which lengths of successive segments are independent. Then, considering the infinite-chromosome limit of the IBD process, we recover previous results (for SMC) and derive new results (for SMC') for the mean number of shared segments longer than a cutoff and the fraction of the chromosome found in such segments. We then use renewal theory to derive an expression (in Laplace space) for the distribution of the number of shared segments and demonstrate implications for demographic inference. We also compute (again, in Laplace space) the distribution of the fraction of the chromosome in shared segments, from which we obtain explicit expressions for the first two moments. Finally, we generalize all results to populations with a variable effective size. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Siegert State Approach to Quantum Defect Theory

    OpenAIRE

    Hategan, C.; Ionescu, R. A.; Wolter, H. H.

    2016-01-01

    The Siegert states are approached in framework of Bloch-Lane-Robson formalism for quantum collisions. The Siegert state is not described by a pole of Wigner R- matrix but rather by the equation $1- R_{nn}L_n = 0$, relating R- matrix element $R_{nn}$ to decay channel logarithmic derivative $L_n$. Extension of Siegert state equation to multichannel system results into replacement of channel R- matrix element $R_{nn}$ by its reduced counterpart ${\\cal R}_{nn}$. One proves the Siegert state is a ...

  15. Managing corporate capabilities:theory and industry approaches.

    Energy Technology Data Exchange (ETDEWEB)

    Slavin, Adam M.

    2007-02-01

    This study characterizes theoretical and industry approaches to organizational capabilities management and ascertains whether there is a distinct ''best practice'' in this regard. We consider both physical capabilities, such as technical disciplines and infrastructure, and non-physical capabilities such as corporate culture and organizational procedures. We examine Resource-Based Theory (RBT), which is the predominant organizational management theory focused on capabilities. RBT seeks to explain the effect of capabilities on competitiveness, and thus provide a basis for investment/divestment decisions. We then analyze industry approaches described to us in interviews with representatives from Goodyear, 3M, Intel, Ford, NASA, Lockheed Martin, and Boeing. We found diversity amongst the industry capability management approaches. Although all organizations manage capabilities and consider them to some degree in their strategies, no two approaches that we observed were identical. Furthermore, we observed that theory is not a strong driver in this regard. No organization used the term ''Resource-Based Theory'', nor did any organization mention any other guiding theory or practice from the organizational management literature when explaining their capabilities management approaches. As such, we concluded that there is no single best practice for capabilities management. Nevertheless, we believe that RBT and the diverse industry experiences described herein can provide useful insights to support development of capabilities management approaches.

  16. Novel Approaches To Numerical Solutions Of Quantum Field Theories

    CERN Document Server

    Petrov, D

    2005-01-01

    Two new approaches to numerically solving Quantum Field Theories are presented. The Source Galerkin technique is a direct approach to determining the generating functional of a theory by solving the Schwinger-Dyson equations. The properties of the Source Galerkin technique are tested by using it to determine the phase structure of the Ultralocal &phis;4 theory. A framework for applying this approach to solving O( N) Nonlinear Sigma model is constructed. The Sinc Function approximation is a highly efficient method of numerically evaluating Feynman diagrams. In the present dissertation the Sinc Function approximation is applied to fermionic fields. The Sinc expanded versions of fermion and photon propagators are derived. The accuracy of this approximation is tested by a direct comparison of the Sinc expanded propagators with exact propagators and by performing several sample calculations of one loop QED diagrams. An analysis of computational properties of the Sinc Function approach is presented.

  17. Vortex lattice theory: A linear algebra approach

    Science.gov (United States)

    Chamoun, George C.

    Vortex lattices are prevalent in a large class of physical settings that are characterized by different mathematical models. We present a coherent and generalized Hamiltonian fluid mechanics-based formulation that reduces all vortex lattices into a classic problem in linear algebra for a non-normal matrix A. Via Singular Value Decomposition (SVD), the solution lies in the null space of the matrix (i.e., we require nullity( A) > 0) as well as the distribution of its singular values. We demonstrate that this approach provides a good model for various types of vortex lattices, and makes it possible to extract a rich amount of information on them. The contributions of this thesis can be classified into four main points. The first is asymmetric equilibria. A 'Brownian ratchet' construct was used which converged to asymmetric equilibria via a random walk scheme that utilized the smallest singular value of A. Distances between configurations and equilibria were measured using the Frobenius norm ||·||F and 2-norm ||·||2, and conclusions were made on the density of equilibria within the general configuration space. The second contribution used Shannon Entropy, which we interpret as a scalar measure of the robustness, or likelihood of lattices to occur in a physical setting. Third, an analytic model was produced for vortex street patterns on the sphere by using SVD in conjunction with expressions for the center of vorticity vector and angular velocity. Equilibrium curves within the configuration space were presented as a function of the geometry, and pole vortices were shown to have a critical role in the formation and destruction of vortex streets. The fourth contribution entailed a more complete perspective of the streamline topology of vortex streets, linking the bifurcations to critical points on the equilibrium curves.

  18. Triangulation of qualitative approaches: hermeneutical phenomenology and grounded theory.

    Science.gov (United States)

    Annells, Merilyn

    2006-10-01

    In this paper, suggestions are offered about the appropriate use of hermeneutic phenomenology and grounded theory in one study. As an alternative to selecting only one qualitative research approach to illuminate a topic of interest about which little is known, two qualitative approaches could be used in a study. Fear of 'method slurring' may prevent this alternative being used. Occasionally, however, credible qualitative researchers have advocated using various research approaches in one study, for example using hermeneutical phenomenology and grounded theory in triangulation. However, if pursuing this direction, several advances in thinking about using qualitative research approaches should be considered. An experience is presented of deciding to use grounded theory and hermeneutic phenomenology in one study. Cautions, practical considerations and alternative options are offered for using these approaches in one study, and the implications of some other possible ways to 'triangulate' qualitative approaches are discussed. Different research approaches can be creatively and successfully used in one study if there has been adequate consideration of vital factors that determine if there is a good 'fit' of the approaches not only with the research problem and question, but also with each other, while also maintaining the integrity of each approach.

  19. Theory and application of MBPT(3) gradients: The density approach

    Science.gov (United States)

    Salter, E. A.; Trucks, Gary W.; Fitzgerald, George; Bartlett, Rodney J.

    1987-10-01

    The density approach to analytic MBPT gradients is discussed. MBPT gradients are considered as special cases of one-electron response properties, where the evaluation of the relaxed MBPT density becomes the central focus of the theory. We develop the theory of MBPT(3) gradients under using this new approach and report a series of initial applications. Earlier developments of the MBPT(3) gradient depended upon solving for the CPHF coefficients for 3 N degrees of freedom and suffered from singularities. Here the virtual-occupied block of the CPHF equation is solved for only one degree of freedom, and the singularities are eliminated. Finally, we report the theory and application of MBPT(2) and MBPT(3) relaxed densities; as a consequence, the computation of analytic one-electron response properties at the MBPT(2) and MBPT(3) levels of theory are now possible.

  20. Nursing Services Delivery Theory: an open system approach

    OpenAIRE

    Meyer, Raquel M; O’Brien-Pallas, Linda L

    2010-01-01

    meyer r.m. & o’brien-pallas l.l. (2010)Nursing services delivery theory: an open system approach. Journal of Advanced Nursing 66(12), 2828–2838. Aim This paper is a discussion of the derivation of the Nursing Services Delivery Theory from the application of open system theory to large-scale organizations. Background The underlying mechanisms by which staffing indicators influence outcomes remain under-theorized and unmeasured, resulting in a ‘black box’ that masks the nature and organization ...

  1. Two approaches to synthesis based on the domain theory

    DEFF Research Database (Denmark)

    Hansen, Claus Thorp; Andreasen, Mogens Myrup

    2002-01-01

    The domain theory is described in this chapter. By a strict distinction between the structural characteristics and the behavioural properties of a mechanical artefact, each domain, i.e. transformation-, organ-, and part domain, becomes a productive view for design of mechanical artefacts....... The functional reasoning within each domain and between the domains seems to be ruled by the function-means law (Hubka´s law). On the basis of the domain theory and the function-means law we present two formal approaches to the synthesis of mechanical artefacts, namely a design-process-oriented approach...

  2. Postmodern Fuzzy System Theory: A Deconstruction Approach Based on Kabbalah

    Directory of Open Access Journals (Sweden)

    Gabriel Burstein

    2014-11-01

    Full Text Available Modern general system theory proposed a holistic integrative approach based on input-state-output dynamics as opposed to the traditional reductionist detail based approach. Information complexity and uncertainty required a fuzzy system theory, based on fuzzy sets and fuzzy logic. While successful in dealing with analysis, synthesis and control of technical engineering systems, general system theory and fuzzy system theory could not fully deal with humanistic and human-like intelligent systems which combine technical engineering components with human or human-like components characterized by their cognitive, emotional/motivational and behavioral/action levels of operation. Such humanistic systems are essential in artificial intelligence, cognitive and behavioral science applications, organization management and social systems, man-machine systems or human factor systems, behavioral knowledge based economics and finance applications. We are introducing here a “postmodern fuzzy system theory” for controlled state dynamics and output fuzzy systems and fuzzy rule based systems using our earlier postmodern fuzzy set theory and a Kabbalah possible worlds model of modal logic and semantics type. In order to create a postmodern fuzzy system theory, we “deconstruct” a fuzzy system in order to incorporate in it the cognitive, emotional and behavioral actions and expressions levels characteristic for humanistic systems. Kabbalah offers a structural, fractal and hierarchic model for integrating cognition, emotions and behavior. We obtain a canonic deconstruction for a fuzzy system into its cognitive, emotional and behavioral fuzzy subsystems.

  3. Shifting Approaches to Planning Theory: Global North and South

    Directory of Open Access Journals (Sweden)

    Vanessa Watson

    2016-12-01

    Full Text Available Planning theory has shifted over time in response to changes in broader social and philosophical theory as well as changes in the material world. Postmodernism and poststructuralism dislodged modernist, rational and technical approaches to planning. Consensualist decision-making theories of the 1980s took forms of communicative and collaborative planning, drawing on Habermasian concepts of power and society. These positions, along with refinements and critiques within the field, have been hegemonic in planning theory ever since. They are, in most cases, presented at a high level of abstraction, make little reference to the political and social contexts in which they are based, and hold an unspoken assumption that they are of universal value, i.e. valid everywhere. Not only does this suggest important research methodology errors but it also renders these theories of little use in those parts of the world which are contextually very different from theory origin—in most cases, the global North. A more recent ‘southern turn’ across a range of social science disciplines, and in planning theory, suggests the possibility of a foundational shift toward theories which acknowledge their situatedness in time and place, and which recognize that extensive global difference in cities and regions renders universalized theorising and narrow conceptual models (especially in planning theory, given its relevance for practice as invalid. New southern theorising in planning is drawing on a range of ideas on societal conflict, informality, identity and ethnicity. Postcolonialism and coloniality have provided a useful frame for situating places historically and geographically in relation to the rest of the world. However, the newness of these explorations still warrants the labelling of this shift as a ‘southern theorizing project’ in planning rather than a suggestion that southern planning theory has emerged.

  4. The special theory of relativity a mathematical approach

    CERN Document Server

    Rahaman, Farook

    2014-01-01

    The book expounds the major topics in the special theory of relativity. It provides a detailed examination of the mathematical foundation of the special theory of relativity, relativistic mass, relativistic mechanics and relativistic electrodynamics.  As well as covariant formulation of relativistic mechanics and electrodynamics, the book discusses the relativistic effect on photons. Using a mathematical approach, the text offers graduate students a clear, concise view of the special theory of relativity. Organized into 14 chapters and two appendices, the content is presented in a logical order, and every topic has been dealt with in a simple and lucid manner. To aid understanding of the subject, the book provides numerous relevant worked examples in every chapter. The book’s mathematical approach helps students in their independent study and motivates them to research the topic further.

  5. Maintaining Healthy Behaviors Following Weight Loss: A Grounded Theory Approach

    Science.gov (United States)

    Zunker, Christie; Cox, Tiffany L.; Ard, Jamy D.; Ivankova, Nataliya V.; Rutt, Candace D.; Baskin, Monica L.

    2011-01-01

    This study explored the process of how women maintained their healthy behaviors after a weight management program using a grounded theory approach. We conducted 2 focus groups and 23 interviews with a purposeful sample of African American and Caucasian women aged 30 and older who lost greater than 5% of their body weight during a weight management…

  6. Anti-bribery control and incentives as agency theory approaches

    Directory of Open Access Journals (Sweden)

    Fabian Teichmann

    2017-11-01

    Full Text Available This article takes an agency theory approach towards bribery in multinational corporations. In particular, it is advocated that incentives could help to align the interests of principals and agents and reduce information asymmetries. This could help to increase anti-bribery compliance and hence support the fight against corruption in Eastern Europe.

  7. Effective field theory approach to LHC Higgs data

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 87; Issue 3. Effective field theory approach to LHC Higgs data. ADAM FALKOWSKI. Special Issue Volume 87 Issue 3 September 2016 Article ID 39. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/pram/087/03/0039. Keywords.

  8. grounded theory approach in sermon analysis of sermons

    African Journals Online (AJOL)

    Grounded theory approach. 116 way (cf. Immink 2005:273-277; Pieterse 2001a). In the preaching event are observable linguistic and social actions that can be analysed empirically, but there is also a spiritual dimension, communication and communion with God, the Word of God as an event that touches the hearts and ...

  9. An Expectancy Theory Motivation Approach to Peer Assessment

    Science.gov (United States)

    Friedman, Barry A.; Cox, Pamela L.; Maher, Larry E.

    2008-01-01

    Group projects are an important component of higher education, and the use of peer assessment of students' individual contributions to group projects has increased. The researchers employed an expectancy theory approach and an experimental design in a field setting to investigate conditions that influence students' motivation to rate their peers'…

  10. Evaluating Action Learning: A Critical Realist Complex Network Theory Approach

    Science.gov (United States)

    Burgoyne, John G.

    2010-01-01

    This largely theoretical paper will argue the case for the usefulness of applying network and complex adaptive systems theory to an understanding of action learning and the challenge it is evaluating. This approach, it will be argued, is particularly helpful in the context of improving capability in dealing with wicked problems spread around…

  11. Stakeholder Theory As an Ethical Approach to Effective Management: applying the theory to multiple contexts

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Harrison

    2015-09-01

    Full Text Available Objective – This article provides a brief overview of stakeholder theory, clears up some widely held misconceptions, explains the importance of examining stakeholder theory from a variety of international perspectives and how this type of research will advance management theory, and introduces the other articles in the special issue. Design/methodology/approach – Some of the foundational ideas of stakeholder theory are discussed, leading to arguments about the importance of the theory to management research, especially in an international context. Findings – Stakeholder theory is found to be a particularly useful perspective for addressing some of the important issues in business from an international perspective. It offers an opportunity to reinterpret a variety of concepts, models and phenomena across may different disciplines. Practical implications – The concepts explored in this article may be applied in many contexts, domestically and internationally, and across business disciplines as diverse as economics, public administration, finance, philosophy, marketing, law, and management. Originality/value – Research on stakeholder theory in an international context is both lacking and sorely needed. This article and the others in this special issue aim to help fill that void.

  12. Parametric statistical inference basic theory and modern approaches

    CERN Document Server

    Zacks, Shelemyahu; Tsokos, C P

    1981-01-01

    Parametric Statistical Inference: Basic Theory and Modern Approaches presents the developments and modern trends in statistical inference to students who do not have advanced mathematical and statistical preparation. The topics discussed in the book are basic and common to many fields of statistical inference and thus serve as a jumping board for in-depth study. The book is organized into eight chapters. Chapter 1 provides an overview of how the theory of statistical inference is presented in subsequent chapters. Chapter 2 briefly discusses statistical distributions and their properties. Chapt

  13. THE CONCEPTUAL APPROACHES FROM VIGOTSKIAN SCHOOL TO SOCIAL REPRESENTATIONS THEORY

    Directory of Open Access Journals (Sweden)

    Maylen Villamañan Alba

    2016-07-01

    Full Text Available This article aims to develop a conceptual reading from the theoretical core of the cultural-historical school to the theory of social representations. The historic-cultural School, influenced by Marxism, far from implying the annulment of the subject, shows how the psychosocial content is expressed from the language-thought relationship to the categories of experience, zone of proximal development and social situation of development. For these authors, man is a social being and their personological singularities are expression of multiple gradations of the universal-contextual law. Also, the theory of social representations addresses the broad impact of a relational social context in shaping the notions of reality, and has a high impact on the social sciences. An approach from the cultural historical perspective would allow deepening and broadening the edges of the theory of social representations, which may contribute to the development of psychology. The analysis is beneficial to the areas of general and social field.

  14. An empirical comparison of Item Response Theory and Classical Test Theory

    Directory of Open Access Journals (Sweden)

    Špela Progar

    2008-11-01

    Full Text Available Based on nonlinear models between the measured latent variable and the item response, item response theory (IRT enables independent estimation of item and person parameters and local estimation of measurement error. These properties of IRT are also the main theoretical advantages of IRT over classical test theory (CTT. Empirical evidence, however, often failed to discover consistent differences between IRT and CTT parameters and between invariance measures of CTT and IRT parameter estimates. In this empirical study a real data set from the Third International Mathematics and Science Study (TIMSS 1995 was used to address the following questions: (1 How comparable are CTT and IRT based item and person parameters? (2 How invariant are CTT and IRT based item parameters across different participant groups? (3 How invariant are CTT and IRT based item and person parameters across different item sets? The findings indicate that the CTT and the IRT item/person parameters are very comparable, that the CTT and the IRT item parameters show similar invariance property when estimated across different groups of participants, that the IRT person parameters are more invariant across different item sets, and that the CTT item parameters are at least as much invariant in different item sets as the IRT item parameters. The results furthermore demonstrate that, with regards to the invariance property, IRT item/person parameters are in general empirically superior to CTT parameters, but only if the appropriate IRT model is used for modelling the data.

  15. LEARNING THE PHONOLOGY OF A LANGUAGE: AN OPTIMALITY THEORY APPROACH

    Directory of Open Access Journals (Sweden)

    Juan Antonio Cutillas Espinosa

    2001-06-01

    Full Text Available Tesar & Srnolensky's book is a valuable reference for traditional approaches to leamability within an Optimality Theory framework. It summarises the reflections of two of the 'founder members' of the discipline. However, other researchers have developed altemative algorithms based on the previous work presented in Tesar & Smolensky which, in our opinion, are more realisfic insofar as they can cope with variation and developmental instability (Boersrna & Hayes 2001. Another interesting question, which affects all computational approaches to leamability, is whether such theories are really grounded or not. Now we know that computers can actually work out the constraint ranking of a language starting frorn some (but not al] initial hierarchies, provided that they are given sufficient overt information. Does that really mean that this is the way the human mind works?. We cannot be satisfied with a simple statement of the type 'if the hurnan mind performed these operations, it would acquire a language'. The only possible answer is that further research on phonological acquisition must be carried out in order to test whether RIPICD and EDCD are indeed at work in phonological acquisition by human beings. Tesar & Srnolensky's Learnability in Opfimality Theory is possibly a must for phonologists. But insofar as the developrnent of OT seems to have wider implications to the extent of having become a revolution in linguistic theory, it is also recomended for linguists in general and specially for applied linguists with some interest in phonological acquisition.

  16. Accounting for Errors in Model Analysis Theory: A Numerical Approach

    Science.gov (United States)

    Sommer, Steven R.; Lindell, Rebecca S.

    2004-09-01

    By studying the patterns of a group of individuals' responses to a series of multiple-choice questions, researchers can utilize Model Analysis Theory to create a probability distribution of mental models for a student population. The eigenanalysis of this distribution yields information about what mental models the students possess, as well as how consistently they utilize said mental models. Although the theory considers the probabilistic distribution to be fundamental, there exists opportunities for random errors to occur. In this paper we will discuss a numerical approach for mathematically accounting for these random errors. As an example of this methodology, analysis of data obtained from the Lunar Phases Concept Inventory will be presented. Limitations and applicability of this numerical approach will be discussed.

  17. Spinning particle approach to higher spin field theory

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Olindo, E-mail: Olindo.Corradini@bo.infn.it [Centro de Estudios en Fisica y Matematicas Basicas y Aplicadas Universidad Autonoma de Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Dipartimento di Fisica, Universita di Bologna via Irnerio 46, I-40126 Bologna (Italy); INFN, Sezione di Bologna via Irnerio 46, I-40126 Bologna (Italy)

    2011-04-01

    We shortly review on the connection between higher-spin gauge field theories and supersymmetric spinning particle models. In such approach the higher spin equations of motion are linked to the first-class constraint algebra associated with the quantization of particle models. Here we consider a class of spinning particle models characterized by local O(N)-extended supersymmetry since these models are known to provide an alternative approach to the geometric formulation of higher spin field theory. We describe the canonical quantization of the models in curved target space and discuss the obstructions that appear in presence of an arbitrarily curved background. We then point out the special role that conformally flat spaces appear to have in such models and present a derivation of the higher-spin curvatures for maximally symmetric spaces.

  18. Effective interactions for light nuclei: an effective (field theory) approach

    OpenAIRE

    Stetcu, I.; Rotureau, J.; Barrett, B.R.; van Kolck, U.

    2009-01-01

    One of the central open problems in nuclear physics is the construction of effective interactions suitable for many-body calculations. We discuss a recently developed approach to this problem, where one starts with an effective field theory containing only fermion fields and formulated directly in a no-core shell-model space. We present applications to light nuclei and to systems of a few atoms in a harmonic-oscillator trap. Future applications and extensions, as well as challenges, are also ...

  19. Number theory an approach through history from Hammurapi to Legendre

    CERN Document Server

    Weil, André

    2007-01-01

    Number Theory or arithmetic, as some prefer to call it, is the oldest, purest, liveliest, most elementary yet sophisticated field of mathematics. It is no coincidence that the fundamental science of numbers has come to be known as the "Queen of Mathematics." Indeed some of the most complex conventions of the mathematical mind have evolved from the study of basic problems of number theory. André Weil, one of the outstanding contributors to number theory, has written an historical exposition of this subject; his study examines texts that span roughly thirty-six centuries of arithmetical work — from an Old Babylonian tablet, datable to the time of Hammurapi to Legendre’s Essai sur la Théorie des Nombres (1798). Motivated by a desire to present the substance of his field to the educated reader, Weil employs an historical approach in the analysis of problems and evolving methods of number theory and their significance within mathematics. In the course of his study Weil accompanies the reader into the worksho...

  20. Sensory conflict in motion sickness: An observer theory approach

    Science.gov (United States)

    Oman, Charles M.

    1989-01-01

    Motion sickness is the general term describing a group of common nausea syndromes originally attributed to motion-induced cerebral ischemia, stimulation of abdominal organ afferent, or overstimulation of the vestibular organs of the inner ear. Sea-, car-, and airsicknesses are the most commonly experienced examples. However, the discovery of other variants such as Cinerama-, flight simulator-, spectacle-, and space sickness in which the physical motion of the head and body is normal or absent has led to a succession of sensory conflict theories which offer a more comprehensive etiologic perspective. Implicit in the conflict theory is the hypothesis that neutral and/or humoral signals originate in regions of the brain subversing spatial orientation, and that these signals somehow traverse to other centers mediating sickness symptoms. Unfortunately, the present understanding of the neurophysiological basis of motion sickness is far from complete. No sensory conflict neuron or process has yet been physiologically identified. To what extent can the existing theory be reconciled with current knowledge of the physiology and pharmacology of nausea and vomiting. The stimuli which causes sickness, synthesizes a contemporary Observer Theory view of the Sensory Conflict hypothesis are reviewed, and a revised model for the dynamic coupling between the putative conflict signals and nausea magnitude estimates is presented. The use of quantitative models for sensory conflict offers a possible new approach to improving the design of visual and motion systems for flight simulators and other virtual environment display systems.

  1. Teachers' implicit personality theories about the gifted: an experimental approach.

    Science.gov (United States)

    Baudson, Tanja Gabriele; Preckel, Franzis

    2013-03-01

    The implicit theories teachers hold about the gifted influence their perception of and behavior toward highly able students, thus impacting the latter's educational opportunities. Two persistent stereotypes about the gifted can be distinguished: the harmony hypothesis (gifted students are superior in almost all domains) and the disharmony hypothesis (giftedness implies maladaptive social behavior and emotional problems). The present study investigated whether teachers' implicit personality theories about the gifted are in line with the harmony or the disharmony hypothesis. Using an experimental vignette approach, we examined 321 prospective and practicing teachers' implicit personality theories (based on the big five personality framework) about students described along three dimensions (ability level, gender, and age, resulting in 8 different vignettes), controlling for teachers' age, gender, experience with gifted students, and knowledge about giftedness. Ability level had the strongest effect on teachers' ratings (partial η² = .60). Students described as gifted were perceived as more open to new experiences, more introverted, less emotionally stable, and less agreeable (all ps < .001). No differences were found for conscientiousness. Gender and its interaction with ability level had a small effect (partial η²s = .04 and .03). Thus, teachers' implicit personality theories about the gifted were in line with the disharmony hypothesis. Possible consequences for gifted identification and education are discussed. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  2. Hamiltonian truncation approach to quenches in the Ising field theory

    CERN Document Server

    Rakovszky, Tibor; Collura, Mario; Kormos, Márton; Takács, Gábor

    2016-01-01

    In contrast to lattice systems where powerful numerical techniques such as matrix product state based methods are available to study the non-equilibrium dynamics, the non-equilibrium behaviour of continuum systems is much harder to simulate. We demonstrate here that Hamiltonian truncation methods can be efficiently applied to this problem, by studying the quantum quench dynamics of the 1+1 dimensional Ising field theory using a truncated free fermionic space approach. After benchmarking the method with integrable quenches corresponding to changing the mass in a free Majorana fermion field theory, we study the effect of an integrability breaking perturbation by the longitudinal magnetic field. In both the ferromagnetic and paramagnetic phases of the model we find persistent oscillations with frequencies set by the low-lying particle excitations even for moderate size quenches. In the ferromagnetic phase these particles are the various non-perturbative confined bound states of the domain wall excitations, while...

  3. Mapping site-based construction workers’ motivation: Expectancy theory approach

    Directory of Open Access Journals (Sweden)

    Parviz Ghoddousi

    2014-03-01

    Full Text Available The aim of this study is to apply a recently proposed model of motivation based on expectancy theory to site-based workers in the construction context and confirm the validity of this model for the construction industry. The study drew upon data from 194 site-based construction workers in Iran to test the proposed model of motivation. To this end, the structural equation modelling (SEM approach based on the confirmatory factor analysis (CFA technique was deployed. The study reveals that the proposed model of expectancy theory incorporating five indicators (i.e. intrinsic instrumentality, extrinsic instrumentality, intrinsic valence, extrinsic valence and expectancy is able to map the process of construction workers’ motivation. Nonetheless, the findings posit that intrinsic indicators could be more effective than extrinsic ones. This proffers the necessity of construction managers placing further focus on intrinsic motivators to motivate workers.

  4. Linear response theory an analytic-algebraic approach

    CERN Document Server

    De Nittis, Giuseppe

    2017-01-01

    This book presents a modern and systematic approach to Linear Response Theory (LRT) by combining analytic and algebraic ideas. LRT is a tool to study systems that are driven out of equilibrium by external perturbations. In particular the reader is provided with a new and robust tool to implement LRT for a wide array of systems. The proposed formalism in fact applies to periodic and random systems in the discrete and the continuum. After a short introduction describing the structure of the book, its aim and motivation, the basic elements of the theory are presented in chapter 2. The mathematical framework of the theory is outlined in chapters 3–5: the relevant von Neumann algebras, noncommutative $L^p$- and Sobolev spaces are introduced; their construction is then made explicit for common physical systems; the notion of isopectral perturbations and the associated dynamics are studied. Chapter 6 is dedicated to the main results, proofs of the Kubo and Kubo-Streda formulas. The book closes with a chapter about...

  5. Chemical reaction network approaches to Biochemical Systems Theory.

    Science.gov (United States)

    Arceo, Carlene Perpetua P; Jose, Editha C; Marin-Sanguino, Alberto; Mendoza, Eduardo R

    2015-11-01

    This paper provides a framework to represent a Biochemical Systems Theory (BST) model (in either GMA or S-system form) as a chemical reaction network with power law kinetics. Using this representation, some basic properties and the application of recent results of Chemical Reaction Network Theory regarding steady states of such systems are shown. In particular, Injectivity Theory, including network concordance [36] and the Jacobian Determinant Criterion [43], a "Lifting Theorem" for steady states [26] and the comprehensive results of Müller and Regensburger [31] on complex balanced equilibria are discussed. A partial extension of a recent Emulation Theorem of Cardelli for mass action systems [3] is derived for a subclass of power law kinetic systems. However, it is also shown that the GMA and S-system models of human purine metabolism [10] do not display the reactant-determined kinetics assumed by Müller and Regensburger and hence only a subset of BST models can be handled with their approach. Moreover, since the reaction networks underlying many BST models are not weakly reversible, results for non-complex balanced equilibria are also needed. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Hamiltonian truncation approach to quenches in the Ising field theory

    Science.gov (United States)

    Rakovszky, T.; Mestyán, M.; Collura, M.; Kormos, M.; Takács, G.

    2016-10-01

    In contrast to lattice systems where powerful numerical techniques such as matrix product state based methods are available to study the non-equilibrium dynamics, the non-equilibrium behaviour of continuum systems is much harder to simulate. We demonstrate here that Hamiltonian truncation methods can be efficiently applied to this problem, by studying the quantum quench dynamics of the 1 + 1 dimensional Ising field theory using a truncated free fermionic space approach. After benchmarking the method with integrable quenches corresponding to changing the mass in a free Majorana fermion field theory, we study the effect of an integrability breaking perturbation by the longitudinal magnetic field. In both the ferromagnetic and paramagnetic phases of the model we find persistent oscillations with frequencies set by the low-lying particle excitations not only for small, but even for moderate size quenches. In the ferromagnetic phase these particles are the various non-perturbative confined bound states of the domain wall excitations, while in the paramagnetic phase the single magnon excitation governs the dynamics, allowing us to capture the time evolution of the magnetisation using a combination of known results from perturbation theory and form factor based methods. We point out that the dominance of low lying excitations allows for the numerical or experimental determination of the mass spectra through the study of the quench dynamics.

  7. Holistic Approach of the Evolution Theory to TNC Genesis

    Directory of Open Access Journals (Sweden)

    Rybalko Yuliia S.

    2014-02-01

    Full Text Available Development of the world economy at the modern stage is characterised with formation of the global model of economic development. Economic evolution theory, from the point of view of its supporters, considers economic development as an irreversible process of growth of complexity, variability and productiveness of production by means of periodical repetition of replacement of technologies, types of products, organisations and institutes, quite surprisingly, insufficiently exhaustively reacted in its development on modern challenges in the form of globalisation and processes caused by a new type of reproduction in the post-industrial society. The article, based on main provisions of the economic evolution theory and modern empiricism, specifies general and specific characteristics of development of trans-national corporations (TNC and provides an improved justification of periodisation of the TNC evolution. The holistic approach of the economic evolution theory to periodisation of the TNC development and the author’s analysis of stages of establishment of TNC give a possibility to identify specific regularities of this development and formulate the hypothesis on probability of coincidence of stages of TNC development and stages of development of the world currency system in the context of time periods, and also to mark out the tendency of formation of corporations of a new generation – mondialised global compositely combined structures.

  8. [Notes on childhood and theory: a Latin American approach].

    Science.gov (United States)

    Bustelo Graffigna, Eduardo

    2012-12-01

    This work seeks to introduce and examine different historically relevant theories and propose certain frameworks that allow for the development of a Latin American theoretical approach based in a new discourse regarding childhood and adolescence. In order to undertake the creation of this Latin American approach, understanding the category of childhood as a social and historical construction, the work draws upon the contributions of structuralism (in particular, childhood as a permanent category, its relational dimension with regards to adulthood and its historical and intercultural dimension) and Foucault and Deleuze's concept of the society of control associated with the category of domination, an essential aspect of Latin American thought. The text was presented as a speech in the V World Congress for the Rights of Children and Adolescents held in San Juan, Argentina, from October 15-19, 2012.

  9. Multi-Robot Searching using Game-Theory Based Approach

    Directory of Open Access Journals (Sweden)

    Yan Meng

    2008-11-01

    Full Text Available This paper proposes a game-theory based approach in a multi–target searching using a multi-robot system in a dynamic environment. It is assumed that a rough priori probability map of the targets' distribution within the environment is given. To consider the interaction between the robots, a dynamic-programming equation is proposed to estimate the utility function for each robot. Based on this utility function, a cooperative nonzero-sum game is generated, where both pure Nash Equilibrium and mixed-strategy Equilibrium solutions are presented to achieve an optimal overall robot behaviors. A special consideration has been taken to improve the real-time performance of the game-theory based approach. Several mechanisms, such as event-driven discretization, one-step dynamic programming, and decision buffer, have been proposed to reduce the computational complexity. The main advantage of the algorithm lies in its real-time capabilities whilst being efficient and robust to dynamic environments.

  10. Evaluating deceased organ donation: a programme theory approach.

    Science.gov (United States)

    Manzano, Ana; Pawson, Ray

    2014-01-01

    Organ donation and transplantation services represent a microcosm of modern healthcare organisations. They are complex adaptive systems. They face perpetual problems of matching supply and demand. They operate under fierce time and resource constraints. And yet they have received relatively little attention from a systems perspective. The purpose of this paper is to consider some of the fundamental issues in evaluating, improving and policy reform in such complex systems. The paper advocates an approach based on programme theory evaluation. The paper explains how the death to donation to transplantation process depends on the accumulation of series of embedded, institutional sub-processes. Evaluators need to be concerned with this whole system rather than with its discrete parts or sectors. Policy makers may expect disappointment if they seek to improve donation rates by applying nudges or administrative reforms at a single point in the implementation chain. These services represent concentrated, perfect storms of complexity and the paper offers guidance to practitioners with bio-medical backgrounds on how such services might be evaluated and improved. For the methodological audience the paper caters for the burgeoning interest in programme theory evaluation while illustrating the design phase of this research strategy.

  11. A semiclassical approach to relativistic nuclear mean field theory

    Energy Technology Data Exchange (ETDEWEB)

    Centelles, M.; Vinas, X.; Barranco, M. (Universitat de Barcelona (Spain)); Schuck, P. (Institut des Sciences Nucleaires, Grenoble (France))

    1993-01-01

    Semiclassical relativistic particle and energy densities for a set of fermions submitted to a scalar field and to the time-like component of a four-vector field are derived in the Wigner-Kirkwood and Thomas Fermi mean field theories, including gradient corrections up to order h[sup 2]. As a test of the validite of the semiclassical method, a simple case is studied. where the scalar potential and the zero component of the four-vector potential are identical and correspond to a harmonic oscillator. The semiclassical approach is then applied to the non-linear [sigma]-[omega] model and the resulting variational equations are solved for finite nuclei and semi-infinite symmetric nuclear matter. In this case Hartree solutions are available and allow for an additional test of the reliability of the h[sup 2] corrections.

  12. THE CONTEMPORARY METHODOLOGICAL APPROACHES AND THEORIES EXPLAINING INTERNATIONAL TOURISM FLOWS

    Directory of Open Access Journals (Sweden)

    Zorina SISCAN

    2017-08-01

    Full Text Available Proceeding from the fact that international tourism is in permanent growth the last decades, and contributes signi­ficantly to the development of contemporary national economies, the authors of the article have focused on methodo­logical and theoretical frame that allows deeper understanding of the touristic flows from various aspects. In doing so, the first author has launched some methodological approaches that allow deepening a perspective research on touristic flows while the second author has concentrated upon grouping and analysis of existing theories used to explain touristic flows. As an outcome, the authors recommend a blend of those approaches and theories to be used for an adequate understanding and managing the existing and perspective touristic flows.ABORDDĂRI METODOLOGICE ȘI TEORII CONTEMPORANE CARE EXPLICĂ FLUXURILE DE TURISM INTERNAȚIONALPornind de la faptul că turismul internațional manifestă permanentă creștere în ultimele decenii, precum și contribuie semnificativ la dezvoltarea economiilor naționale contemporane, autorii articolului s-au axat pe cadrul metodologic și teoretic ce ar permite conceperea aprofundată a fluxurilor de turism internațional. Primul autor a lansat unele abordări metodologice care ar contribui la aprofundarea cercetărilor de perspectivă ale fluxurilor turistice, iar cel de-al doilea autor și-a concentrat atenția asupra grupării și analizei teoriilor existente în care se explică natura fluxurilor de turism. Ca rezultat, autorii recomandă utilizarea îmbinării organice a abordărilor și teoriilor considerate pentru perceperea și gestionarea adecvată a fluxurilor de turism existente și de perspectivă.

  13. Field Theory in Organizational Psychology: An Analysis of Theoretical Approaches in Leadership.

    Science.gov (United States)

    Garcia, Joseph E.

    This literature review examines Kurt Lewin's influence in leadership psychology. Characteristics of field theory are described in detail and utilized in analyzing leadership research, including the trait approach, leader behavior studies, contingency theory, path-goal theory, and leader decision theory. Important trends in leadership research are…

  14. Making Sense of Grounded Theory Approach: Implications for Medial Education Research

    OpenAIRE

    Tavakol M; Torabi S; Zeialoo AA

    2006-01-01

    This article first gives a definition of grounded theory and its development and use in medicine and medical education. The fundamental differences of grounded theory with quantitative methods are discussed along a full discussion of the steps required to use a grounded theory approach. At the end the questions in the area of medical education which can best addressed with this approach are provided

  15. Random Vector and Matrix Theories: A Renormalization Group Approach

    Science.gov (United States)

    Zinn-Justin, Jean

    2014-09-01

    Random matrices in the large N expansion and the so-called double scaling limit can be used as toy models for quantum gravity: 2D quantum gravity coupled to conformal matter. This has generated a tremendous expansion of random matrix theory, tackled with increasingly sophisticated mathematical methods and number of matrix models have been solved exactly. However, the somewhat paradoxical situation is that either models can be solved exactly or little can be said. Since the solved models display critical points and universal properties, it is tempting to use renormalization group ideas to determine universal properties, without solving models explicitly. Initiated by Br\\'ezin and Zinn-Justin, the approach has led to encouraging results, first for matrix integrals and then quantum mechanics with matrices, but has not yet become a universal tool as initially hoped. In particular, general quantum field theories with matrix fields require more detailed investigations. To better understand some of the encountered difficulties, we first apply analogous ideas to the simpler O(N) symmetric vector models, models that can be solved quite generally in the large N limit. Unlike other attempts, our method is a close extension of Br\\'ezin and Zinn-Justin. Discussing vector and matrix models with similar approximation scheme, we notice that in all cases (vector and matrix integrals, vector and matrix path integrals in the local approximation), at leading order, non-trivial fixed points satisfy the same universal algebraic equation, and this is the main result of this work. However, its precise meaning and role have still to be better understood.

  16. FROM CONTRACTUAL APPROACH OF FIRM TO THEORIES OF KNOWLEDGE

    Directory of Open Access Journals (Sweden)

    Grigore Maria Zenovia

    2009-05-01

    Full Text Available The object of contractual theories is describing exchange relation between agents, considering institutional and informational restriction in which they evolve. From trials of removing insufficiency in contractual theories new representations gradually

  17. The geometry of resonance tongues : a singularity theory approach

    NARCIS (Netherlands)

    Broer, Hendrik; Golubitsky, Martin; Vegter, Gert

    Resonance tongues and their boundaries are studied for nondegenerate and (certain) degenerate Hopf bifurcations of maps using singularity theory methods of equivariant contact equivalence and universal unfoldings. We recover the standard theory of tongues (the nondegencrate case) in a

  18. Adopting a Grounded Theory Approach to Cultural-Historical Research: Conflicting Methodologies or Complementary Methods?

    Directory of Open Access Journals (Sweden)

    Jayson Seaman PhD

    2008-03-01

    Full Text Available Grounded theory has long been regarded as a valuable way to conduct social and educational research. However, recent constructivist and postmodern insights are challenging long-standing assumptions, most notably by suggesting that grounded theory can be flexibly integrated with existing theories. This move hinges on repositioning grounded theory from a methodology with positivist underpinnings to an approach that can be used within different theoretical frameworks. In this article the author reviews this recent transformation of grounded theory, engages in the project of repositioning it as an approach by using cultural historical activity theory as a test case, and outlines several practical methods implied by the joint use of grounded theory as an approach and activity theory as a methodology. One implication is the adoption of a dialectic, as opposed to a constructivist or objectivist, stance toward grounded theory inquiry, a stance that helps move past the problem of emergence versus forcing.

  19. A Signal Detection Theory Approach to Evaluating Oculometer Data Quality

    Science.gov (United States)

    Latorella, Kara; Lynn, William, III; Barry, John S.; Kelly, Lon; Shih, Ming-Yun

    2013-01-01

    Currently, data quality is described in terms of spatial and temporal accuracy and precision [Holmqvist et al. in press]. While this approach provides precise errors in pixels, or visual angle, often experiments are more concerned with whether subjects'points of gaze can be said to be reliable with respect to experimentally-relevant areas of interest. This paper proposes a method to characterize oculometer data quality using Signal Detection Theory (SDT) [Marcum 1947]. SDT classification results in four cases: Hit (correct report of a signal), Miss (failure to report a ), False Alarm (a signal falsely reported), Correct Reject (absence of a signal correctly reported). A technique is proposed where subjects' are directed to look at points in and outside of an AOI, and the resulting Points of Gaze (POG) are classified as Hits (points known to be internal to an AOI are classified as such), Misses (AOI points are not indicated as such), False Alarms (points external to AOIs are indicated as in the AOI), or Correct Rejects (points external to the AOI are indicated as such). SDT metrics describe performance in terms of discriminability, sensitivity, and specificity. This paper presentation will provide the procedure for conducting this assessment and an example of data collected for AOIs in a simulated flightdeck environment.

  20. Laughter as an approach to vocal evolution: The bipedal theory.

    Science.gov (United States)

    Provine, Robert R

    2017-02-01

    Laughter is a simple, stereotyped, innate, human play vocalization that is ideal for the study of vocal evolution. The basic approach of describing the act of laughter and when we do it has revealed a variety of phenomena of social, linguistic, and neurological significance. Findings include the acoustic structure of laughter, the minimal voluntary control of laughter, the punctuation effect (which describes the placement of laughter in conversation and indicates the dominance of speech over laughter), and the role of laughter in human matching and mating. Especially notable is the use of laughter to discover why humans can speak and other apes cannot. Quadrupeds, including our primate ancestors, have a 1:1 relation between breathing and stride because their thorax must absorb forelimb impacts during running. The direct link between breathing and locomotion limits vocalizations to short, simple utterances, such as the characteristic panting chimpanzee laugh (one sound per inward or outward breath). The evolution of bipedal locomotion freed the respiration system of its support function during running, permitting greater breath control and the selection for human-type laughter (a parsed exhalation), and subsequently the virtuosic, sustained, expiratory vocalization of speech. This is the basis of the bipedal theory of speech evolution.

  1. The analysis and evaluation of legal argumentation: approaches from legal theory and argumentation theory

    NARCIS (Netherlands)

    Feteris, E.; Kloosterhuis, H.

    2009-01-01

    In the past thirty years legal argumentation has become an important interdisciplinary field of interest. The study of legal argumentation draws its data, assumptions and methods from disciplines such as legal theory, legal philosophy, logic, argumentation theory, rhetoric, linguistics, literary

  2. Quantum theory from first principles an informational approach

    CERN Document Server

    D'Ariano, Giacomo Mauro; Perinotti, Paolo

    2017-01-01

    Quantum theory is the soul of theoretical physics. It is not just a theory of specific physical systems, but rather a new framework with universal applicability. This book shows how we can reconstruct the theory from six information-theoretical principles, by rebuilding the quantum rules from the bottom up. Step by step, the reader will learn how to master the counterintuitive aspects of the quantum world, and how to efficiently reconstruct quantum information protocols from first principles. Using intuitive graphical notation to represent equations, and with shorter and more efficient derivations, the theory can be understood and assimilated with exceptional ease. Offering a radically new perspective on the field, the book contains an efficient course of quantum theory and quantum information for undergraduates. The book is aimed at researchers, professionals, and students in physics, computer science and philosophy, as well as the curious outsider seeking a deeper understanding of the theory.

  3. Reflecting on the challenges of choosing and using a grounded theory approach.

    Science.gov (United States)

    Markey, Kathleen; Tilki, Mary; Taylor, Georgina

    2014-11-01

    To explore three different approaches to grounded theory and consider some of the possible philosophical assumptions underpinning them. Grounded theory is a comprehensive yet complex methodology that offers a procedural structure that guides the researcher. However, divergent approaches to grounded theory present dilemmas for novice researchers seeking to choose a suitable research method. This is a methodology paper. This is a reflexive paper that explores some of the challenges experienced by a PhD student when choosing and operationalising a grounded theory approach. Before embarking on a study, novice grounded theory researchers should examine their research beliefs to assist them in selecting the most suitable approach. This requires an insight into the approaches' philosophical assumptions, such as those pertaining to ontology and epistemology. Researchers need to be clear about the philosophical assumptions underpinning their studies and the effects that different approaches will have on the research results. This paper presents a personal account of the journey of a novice grounded theory researcher who chose a grounded theory approach and worked within its theoretical parameters. Novice grounded theory researchers need to understand the different philosophical assumptions that influence the various grounded theory approaches, before choosing one particular approach.

  4. Supplementary Appendix for: Constrained Perturbation Regularization Approach for Signal Estimation Using Random Matrix Theory

    KAUST Repository

    Suliman, Mohamed

    2016-01-01

    In this supplementary appendix we provide proofs and additional simulation results that complement the paper (constrained perturbation regularization approach for signal estimation using random matrix theory).

  5. Defended By Reason: Can Theory Provide Another Approach to Transformation?

    Science.gov (United States)

    2003-01-01

    would, in Mitchell’s opinion , demoralize enemy populations causing a quick capitulation to the nation that had air superiority.34 The one area where...88 Julian Lider , Military Theory (New York: St. Martin’s Press, 1983) 262-263. 89 Ibid., 261-262. 42 However, there is a recent...papers ensuring a unifying thread into a general theory of war for America. Julian Lider proposes that a military theory should contain the following: 1

  6. An Activity Systems Theory Approach to Agent Technology

    OpenAIRE

    Zhang, Peng; Bai, Guohua

    2005-01-01

    In the last decade, Activity Theory has been discussed a lot in Human-Computer Interaction (HCI) and Computer Supported Cooperative Work (CSCW). Activity Theory was used both theoretically as an analytical method and practically as a development framework for Information Systems. Meanwhile, there is a new trench from Artificial Intelligence. Artificial Intelligence researchers find that the fruit from Activity Theory study may contribute, especially to Agent Technology, with socio-psychologic...

  7. CURRENT APPROACHES TO PRAGMATICS. TOWARDS A NEW LINGUISTIC THEORY

    Directory of Open Access Journals (Sweden)

    Liviu Mihail Marinescu

    2006-05-01

    Full Text Available Out of all issues in the theory of language usage, the speech act theory has probably aroused the widest interest. Psychologists have suggested that the acquirement of the concepts underlying speech acts may be a prerequisite for the acquisition of language in general, literary critics have looked to speech act theory for an illumination of textual subtleties or for an understanding of the nature of literary genres, philosophers have seen potential applications to the status of ethical statements, while linguists have seen the notions of speech act theory as variously applicable to problems in syntax, semantics, pragmatics, second language learning, and elsewhere.

  8. Structure and measurement of depression in youths: applying item response theory to clinical data.

    Science.gov (United States)

    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

    2011-12-01

    Our goals in this article 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 3,403 children and adolescents from 12 contributing clinical and nonclinical samples; all participants had 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. Furthermore, use of IRT-based information about symptom severity and discriminability in the measurement of depression severity was shown to reduce measurement error and increase measurement fidelity.

  9. Quality of life in schizophrenia: A grounded theory approach

    Directory of Open Access Journals (Sweden)

    Jackson Mike

    2003-08-01

    Full Text Available Abstract Background Research into health related quality of life (HRQoL in schizophrenia has predominantly been conducted using lengthy interviewer administered questionnaires, many of which have not been validated for use with schizophrenic samples. The present study seeks to address the dearth of qualitative research by conducting a small-scale qualitative exploration of the impact of schizophrenia on HRQoL. Method The study was conducted using the qualitative approach of grounded theory. Six individuals with a diagnosis of schizophrenia participated (3 men, 3 women. Mean age of participants was 33.3 years (range 20–55, mean length of illness was 12 years (range 2–38 years and average length of interviews was 47 minutes (range 20–70. Results Ten HRQoL domains were identified as being important: (1 barriers placed on relationships; (2 reduced control of behaviours and actions; (3 loss of opportunity to fulfil occupational roles; (4 financial constraints on activities and plans; (5 subjective experience of psychotic symptoms; (6 side effects and attitudes to medication; (7 psychological responses to living with schizophrenia; (8 labelling and attitudes from others; (9 concerns for the future and (10 positive outcomes from experiences. Conclusions Domains identified by participants encompassed a wide range of factors that may be expected to contribute generally to engaging in a positive quality of life. Participants identified that it was the loss of these things as a direct consequence of having schizophrenia that influenced their HRQoL. It would appear that in the main, factors that are secondary to the experience of schizophrenia are of most importance to participants. Suggestions are also made in the discussion for future research.

  10. Data, instruments, and theory a dialectical approach to understanding science

    CERN Document Server

    Ackermann, Robert John

    1985-01-01

    Robert John Ackermann deals decisively with the problem of relativism that has plagued post-empiricist philosophy of science. Recognizing that theory and data are mediated by data domains (bordered data sets produced by scientific instruments), he argues that the use of instruments breaks the dependency of observation on theory and thus creates a reasoned basis for scientific objectivity.

  11. The Elaboration Theory's Procedure for Designing Instruction: A Conceptual Approach.

    Science.gov (United States)

    Reigeluth, Charles M.; Darwazeh, Afnan

    1982-01-01

    Describes the use of elaboration theory in selecting, sequencing, synthesizing, and summarizing instructional content that is predominantly conceptual in nature. The elaboration theory is summarized and the instructional design process based upon it is outlined. Six figures, a glossary, and a 27-item reference list are included. (Author/JL)

  12. Empowerment in School Nursing Practice: A Grounded Theory Approach

    Science.gov (United States)

    Broussard, Lisa

    2007-01-01

    Professional empowerment is vital to nurses' productivity and job satisfaction. A grounded theory study was conducted to describe the basic social process experienced by school nurses in relation to professional empowerment. Interviews with 10 school nurses led to the development of a situation-specific theory of school nurse empowerment,…

  13. New Approaches and Applications for Monte Carlo Perturbation Theory

    Energy Technology Data Exchange (ETDEWEB)

    Aufiero, Manuele; Bidaud, Adrien; Kotlyar, Dan; Leppänen, Jaakko; Palmiotti, Giuseppe; Salvatores, Massimo; Sen, Sonat; Shwageraus, Eugene; Fratoni, Massimiliano

    2017-02-01

    This paper presents some of the recent and new advancements in the extension of Monte Carlo Perturbation Theory methodologies and application. In particular, the discussed problems involve Brunup calculation, perturbation calculation based on continuous energy functions, and Monte Carlo Perturbation Theory in loosely coupled systems.

  14. Geometrical approach to duality in N=1 supersymmetric theories

    CERN Document Server

    Brax, P; Savoy, C A; Brax, Ph

    1997-01-01

    We investigate the geometry of the moduli spaces of dual electric and magnetic N=1 supersymmetric field theories. Using the SU(N_c) gauge group as a guideline we show that the electric and magnetic moduli spaces coincide for a suitable choice of the Kahler potential of the magnetic theory. We analyse the Kahler structure of the dual moduli spaces.

  15. General Systems Theory Approaches to Organizations: Some Problems in Application

    Science.gov (United States)

    Peery, Newman S., Jr.

    1975-01-01

    Considers the limitations of General Systems Theory (GST) as a major paradigm within administrative theory and concludes that most systems formulations overemphasize growth and show little appreciation for intraorganizational conflict, diversity of values, and political action within organizations. Suggests that these limitations are mainly due to…

  16. A geometrical approach to two-dimensional Conformal Field Theory

    NARCIS (Netherlands)

    Dijkgraaf, Robertus Henricus

    1989-01-01

    This thesis is organized in the following way. In Chapter 2 we will give a brief introduction to conformal field theory along the lines of standard quantum field theory, without any claims to originality. We introduce the important concepts of the stress-energy tensor, the Virasoro algebra, and

  17. A novel genealogical approach to neutral biodiversity theory

    NARCIS (Netherlands)

    Etienne, R.S.; Olff, H.

    2004-01-01

    Current neutral theory in community ecology views local biodiversity as a result of the interplay between speciation, extinction and immigration. Simulations and a mean-field approximation have been used to study this neutral theory. As simulations have limitations of convergence and the mean-field

  18. A novel genealogical approach to neutral biodiversity theory

    NARCIS (Netherlands)

    Etienne, RS; Olff, H

    Current neutral theory in community ecology views local biodiversity as a result of the interplay between speciation, extinction and immigration. Simulations and a mean-field approximation have been used to study this neutral theory. As simulations have limitations of convergence and the mean-field

  19. Critical Theory-Based Approaches in Geography Teaching Departments in Turkey

    Science.gov (United States)

    Bilgili, Münür

    2018-01-01

    The aim of this study is to understand the relationships between critical theory-based approaches and its implementations in geography teaching departments in Turkey. Critical theory dates back to 1930s and has developed over time aiming to deal with institutions, culture and society through critical lens. Currently, critical theory-based research…

  20. A Critical Comparison of Transformation and Deep Approach Theories of Learning

    Science.gov (United States)

    Howie, Peter; Bagnall, Richard

    2015-01-01

    This paper reports a critical comparative analysis of two popular and significant theories of adult learning: the transformation and the deep approach theories of learning. These theories are operative in different educational sectors, are significant, respectively, in each, and they may be seen as both touching on similar concerns with learning…

  1. Modeling Routinization in Games: An Information Theory Approach

    DEFF Research Database (Denmark)

    Wallner, Simon; Pichlmair, Martin; Hecher, Michael

    2015-01-01

    -time, discrete-space Markov chains and information theory to measure the actual error between the dynamically trained models and the player interaction. Preliminary research supports the hypothesis that Markov chains can be effectively used to model routinization in games. A full study design is presented......Routinization is the result of practicing until an action stops being a goal-directed process. This paper formulates a definition of routinization in games based on prior research in the fields of activity theory and practice theory. Routinization is analyzed using the formal model of discrete...

  2. Statistical approach to quantum field theory an introduction

    CERN Document Server

    Wipf, Andreas

    2013-01-01

    Over the past few decades the powerful methods of statistical physics and Euclidean quantum field theory have moved closer together, with common tools based on the use of path integrals. The interpretation of Euclidean field theories as particular systems of statistical physics has opened up new avenues for understanding strongly coupled quantum systems or quantum field theories at zero or finite temperatures. Accordingly, the first chapters of this book contain a self-contained introduction to path integrals in Euclidean quantum mechanics and statistical mechanics. The resulting high-dimensional integrals can be estimated with the help of Monte Carlo simulations based on Markov processes. The most commonly used algorithms are presented in detail so as to prepare the reader for the use of high-performance computers as an “experimental” tool for this burgeoning field of theoretical physics. Several chapters are then devoted to an introduction to simple lattice field theories and a variety of spin systems w...

  3. Approaches to a constitutional function on theory of crime

    Directory of Open Access Journals (Sweden)

    Yvan Montoya Vivanco

    2013-12-01

    Full Text Available After presenting assumptions of neo constitutionalism impact incriminal law, this article raises the possibilities of rebuild contents of categories on crime’s theory towards fundamental principles and rights recognized (explicitly or implicitly in the Constitution.

  4. Toward a Theory of Strategic Communication: A Relationship Management Approach

    Science.gov (United States)

    2012-03-22

    Recent Challenges and New Research,” in Public Relations Research: An International Perspective, ed. Danny Moss , Toby MacManus, and Dejan Vercic...London: International Thomson Business Press, 1997), 9. 49 Ibid. 50 Chun-Ju Flora Hung, “Toward the Theory of Relationship Management in Public...Relationship Management in Public Relations: Dimensions of an Organization-Public Relationship,” 55-65. 70 Chun-Ju Flora Hung, “Toward the Theory of

  5. The study of the nonprofit enterprise : theories and approaches

    OpenAIRE

    Anheier, Helmut K.; BenNer, Anver

    2014-01-01

    This volume addresses the need to revisit the economic theories from the last two decades that have contributed to the development of a concentrated research agenda on nonprofit organizations. Long neglected as a topic of theorizing and empirical investigation by mainstream economics in particular, these initial theories of nonprofit organizations from the late 1970s and early 1980s continue to shape theoretical and conceptual efforts. Importantly, their influence extends beyond economics and...

  6. A Meme-Based Approach to Oral Traditional Theory

    Directory of Open Access Journals (Sweden)

    Michael D. C. Drout

    2006-10-01

    Full Text Available A meme is the simplest unit of cultural replication. This paper adapts meme theory to explain the workings of several aspects of oral traditions––traditional referentiality, anaphora, and the use of repeated metrical patterns. All three of these phenomena can be explained by operations of repetition and pattern-recognition. This paper ultimately illustrates that the development of meme theory is an important first step towards a wholly materialist cultural poetics.

  7. Versatility of field theory motivated nuclear effective Lagrangian approach

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, P. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Sharma, B.K. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India)]. E-mail: bharat@iopb.res.in; Sahu, P.K. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Patra, S.K. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Sil, Tapas [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Centelles, M. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Vinas, X. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)

    2004-11-04

    We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei.

  8. Making Sense of Grounded Theory Approach: Implications for Medial Education Research

    Directory of Open Access Journals (Sweden)

    Mohsen Tavokol

    2009-02-01

    Full Text Available This article first gives a definition of grounded theory and its development and use in medicine and medical education. The fundamental differences of grounded theory with quantitative methods are discussed along a full discussion of the steps required to use a grounded theory approach. At the end the questions in the area of medical education which can best addressed with this approach are provided. 

  9. The stability concept of evolutionary game theory a dynamic approach

    CERN Document Server

    1992-01-01

    These Notes grew from my research in evolutionary biology, specifically on the theory of evolutionarily stable strategies (ESS theory), over the past ten years. Personally, evolutionary game theory has given me the opportunity to transfer my enthusiasm for abstract mathematics to more practical pursuits. I was fortunate to have entered this field in its infancy when many biologists recognized its potential but were not prepared to grant it general acceptance. This is no longer the case. ESS theory is now a rapidly expanding (in both applied and theoretical directions) force that no evolutionary biologist can afford to ignore. Perhaps, to continue the life-cycle metaphor, ESS theory is now in its late adolescence and displays much of the optimism and exuberance of this exciting age. There are dangers in writing a text about a theory at this stage of development. A comprehensive treatment would involve too many loose ends for the reader to appreciate the central message. On the other hand, the current central m...

  10. Tax Reform in Brazil: a Public Choice Theory approach

    Directory of Open Access Journals (Sweden)

    Allan Silveira dos Santos

    2013-12-01

    Full Text Available This article aims to analyze tax reform necessity and the barriers to the implementation of tax reform at the light of public choice theory. The research identifies the arguments that provides the explanation for the tax reform does not occur in Brazil. The question that the article searches to answer is: what are the justifications for the Brazil not have done tax reform? The literature review addresses the failures of government, public choice theory and the theory of optimal taxation. The evidence and studies show that there are reasons to think about a tax system more consistent with the Brazilian reality, indicating the existence of "government failures" that may be the probable cause of impairment of the tax reform.

  11. Statistical approach to quantum field theory. An introduction

    Energy Technology Data Exchange (ETDEWEB)

    Wipf, Andreas [Jena Univ. (Germany). Theoretisch-Physikalisches Inst.

    2013-02-01

    Based on course-tested notes and pedagogical in style. Authored by a leading researcher in the field. Contains end-of-chapter problems and listings of short, useful computer programs. Authored by a leading researcher in the field. Contains end-of-chapter problems and listings of short, useful computer programs. Contains end-of-chapter problems and listings of short, useful computer programs. Over the past few decades the powerful methods of statistical physics and Euclidean quantum field theory have moved closer together, with common tools based on the use of path integrals. The interpretation of Euclidean field theories as particular systems of statistical physics has opened up new avenues for understanding strongly coupled quantum systems or quantum field theories at zero or finite temperatures. Accordingly, the first chapters of this book contain a self-contained introduction to path integrals in Euclidean quantum mechanics and statistical mechanics. The resulting high-dimensional integrals can be estimated with the help of Monte Carlo simulations based on Markov processes. The most commonly used algorithms are presented in detail so as to prepare the reader for the use of high-performance computers as an ''experimental'' tool for this burgeoning field of theoretical physics. Several chapters are then devoted to an introduction to simple lattice field theories and a variety of spin systems with discrete and continuous spins, where the ubiquitous Ising model serves as an ideal guide for introducing the fascinating area of phase transitions. As an alternative to the lattice formulation of quantum field theories, variants of the flexible renormalization group methods are discussed in detail. Since, according to our present-day knowledge, all fundamental interactions in nature are described by gauge theories, the remaining chapters of the book deal with gauge theories without and with matter. This text is based on course-tested notes for graduate

  12. A Game Theory Approach for Product Specialization in International Trade

    Directory of Open Access Journals (Sweden)

    Ioana-Veronica ALEXA

    2011-11-01

    Full Text Available Game theory, in its most basic form, considers two players and analyses the different strategies that they can use and the effect that these strategies will have on each player. International trade allows countries to use better their resources (labor, technology or capital. Since countries have different capital or natural resources, some of them will produce a good more efficiently than others and therefore could sell it cheaper than other countries. By using game theory in international trade we could determine if the H-O-S model is correct and what would be the best specialization for each country.

  13. Network analysis and synthesis a modern systems theory approach

    CERN Document Server

    Anderson, Brian D O

    2006-01-01

    Geared toward upper-level undergraduates and graduate students, this book offers a comprehensive look at linear network analysis and synthesis. It explores state-space synthesis as well as analysis, employing modern systems theory to unite the classical concepts of network theory. The authors stress passive networks but include material on active networks. They avoid topology in dealing with analysis problems and discuss computational techniques. The concepts of controllability, observability, and degree are emphasized in reviewing the state-variable description of linear systems. Explorations

  14. Majorization theory approach to the Gaussian channel minimum entropy conjecture.

    Science.gov (United States)

    García-Patrón, Raúl; Navarrete-Benlloch, Carlos; Lloyd, Seth; Shapiro, Jeffrey H; Cerf, Nicolas J

    2012-03-16

    A long-standing open problem in quantum information theory is to find the classical capacity of an optical communication link, modeled as a Gaussian bosonic channel. It has been conjectured that this capacity is achieved by a random coding of coherent states using an isotropic Gaussian distribution in phase space. We show that proving a Gaussian minimum entropy conjecture for a quantum-limited amplifier is actually sufficient to confirm this capacity conjecture, and we provide a strong argument towards this proof by exploiting a connection between quantum entanglement and majorization theory.

  15. [The search for theory-practice interaction in the nursing information system -- approach from grounded theory].

    Science.gov (United States)

    Santos, Sérgio Ribeiro dos; Nóbrega, Maria Miriam Lima da

    2004-01-01

    This qualitative study aimed to understand, through nursing discourse, the relation between theory and practice in nursing and its implications for the development of information systems. Grounded theory was used as a methodological reference framework. The study population consisted of nurses who work at the clinic of a school hospital. Data analysis resulted in the main category: The search for theory-practice interaction in the nursing information system. This process was formed by the integration among categories, based on Strauss and Corbin's paradigm as a model with two phenomena: the attempt to apply the formal models in nursing practice and the perspective of the theory-practice gap in the nursing information system.

  16. Learning in public sector organizations: A theory of action approach

    NARCIS (Netherlands)

    Visser, M.; Togt, K. van der

    2016-01-01

    The importance of learning has since long been acknowledged for both business and public sector organizations. However, learning theory and research have tended to neglect the differences between these organizations, and to develop in separate and unrelated directions. To address these developments,

  17. The Embedded Self: A Social Networks Approach to Identity Theory

    Science.gov (United States)

    Walker, Mark H.; Lynn, Freda B.

    2013-01-01

    Despite the fact that key sociological theories of self and identity view the self as fundamentally rooted in networks of interpersonal relationships, empirical research investigating how personal network structure influences the self is conspicuously lacking. To address this gap, we examine links between network structure and role identity…

  18. INTEGRATIVE APPROACH ON FRAMING THEORY FROM ITS MULTIPARADIGMATIC CONDITION

    Directory of Open Access Journals (Sweden)

    Juan Antonio Marín Albaladejo

    2014-06-01

    Full Text Available Framing theory has reached an increasing role in media communication research, including common principles between different research perspectives. Besides the multiple ways of understanding the concept of frame, a controversy about the types of frames exists. Despite considerable integrating research efforts (D’Angelo, 2002; De Vreese, 2005; Entman, 1993, 2004; López-Rabadán, 2010; Matthes, 2012; Reese, 2007; Scheufele, 1999, scholars have not reached yet full conceptual and methodological convergence, so that definitions, theoretical models, frames measuring mode, types of frames, processes or effects differ in each study (Scheufele, 1999. This article provides an updated review of the different paradigms that define research efforts on this theory, and mentions the advantages to invest in an integrative model or paradigmatic synthesis for future studies. Through a comprehensive review of the published literature, we propose two objectives. On the one hand, to provide a taxonomy of the types of frame to clarify differences detected among studies labeled under this theory. It also seeks to justify the need to consider Framing theory as a multiparadigmatic research program (D'Angelo, 2002 that could include all perspectives established so far.

  19. Institutional economics and economic organisation theory: An integrated approach

    NARCIS (Netherlands)

    Slangen, L.H.G.; Loucks, L.A.; Slangen, A.H.L.

    2008-01-01

    This publication presents one of the first attempts to integrate two emerging bodies of economic research: institutional economics and organizational theory. It begins within the framework of neoclassical economics, and then extends the boundaries of this framework to offer answers to questions that

  20. Institutional economics and economic organisation theory : an integrated approach

    NARCIS (Netherlands)

    Slangen, L.H.G.; Loucks, L.; Slangen, A.H.L.

    2008-01-01

    This publication presents one of the first attempts to integrate two emerging bodies of economic research: institutional economics and organizational theory. It begins within the framework of neoclassical economics, and then extends the boundaries of this framework to offer answers to questions that

  1. Teachers' Implicit Personality Theories about the Gifted: An Experimental Approach

    Science.gov (United States)

    Baudson, Tanja Gabriele; Preckel, Franzis

    2013-01-01

    The implicit theories teachers hold about the gifted influence their perception of and behavior toward highly able students, thus impacting the latter's educational opportunities. Two persistent stereotypes about the gifted can be distinguished: the harmony hypothesis (gifted students are superior in almost all domains) and the disharmony…

  2. Purchasing alignment under multiple contingencies: a configuration theory approach.

    NARCIS (Netherlands)

    Mikalef, P.; Pateli, A.; Batenburg, R.S.; Wetering, R. van de

    2015-01-01

    Purpose: Strategic alignment is a theory-based state that is considered as crucial for organizations in order to realize performance gains from information technology (IT) investments and deployments. Within the domain of purchasing and supply chain management there has been a growing interest on

  3. Renormalization of gauge theories in the background-field approach arXiv

    CERN Document Server

    Barvinsky, Andrei O.; Herrero-Valea, Mario; Sibiryakov, Sergey M.; Steinwachs, Christian F.

    Using the background-field method we demonstrate the Becchi-Rouet-Stora-Tyutin (BRST) structure of counterterms in a broad class of gauge theories. In other words, the renormalization procedure for these gauge theories is compatible with their gauge invariance. This class encompasses Yang-Mills theories (with possibly Abelian subgroups) and relativistic gravity, including both renormalizable and non-renormalizable (effective) theories. Our results also hold for non-relativistic models such as Yang-Mills theories with anisotropic scaling or Horava gravity. They strengthen and generalize the existing results in the literature concerning the renormalization of gauge systems. We illustrate our general approach with several explicit examples.

  4. Coulomb-gas approach for boundary conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Shinsuke E-mail: kawai@thphys.ox.ac.uk

    2002-05-20

    We present a construction of boundary states based on the Coulomb-gas formalism of Dotsenko and Fateev. It is shown that Neumann-like coherent states on the charged bosonic Fock space provide a set of boundary states with consistent modular properties. Such coherent states are characterised by the boundary charges, which are related to the number of bulk screening operators through the charge neutrality condition. We illustrate this using the Ising model as an example, and show that all of its known consistent boundary states are reproduced in our formalism. This method applies to c<1 minimal conformal theories and provides an unified computational tool for studying boundary states of such theories.

  5. Understanding visualization: a formal approach using category theory and semiotics.

    Science.gov (United States)

    Vickers, Paul; Faith, Joe; Rossiter, Nick

    2013-06-01

    This paper combines the vocabulary of semiotics and category theory to provide a formal analysis of visualization. It shows how familiar processes of visualization fit the semiotic frameworks of both Saussure and Peirce, and extends these structures using the tools of category theory to provide a general framework for understanding visualization in practice, including: Relationships between systems, data collected from those systems, renderings of those data in the form of representations, the reading of those representations to create visualizations, and the use of those visualizations to create knowledge and understanding of the system under inspection. The resulting framework is validated by demonstrating how familiar information visualization concepts (such as literalness, sensitivity, redundancy, ambiguity, generalizability, and chart junk) arise naturally from it and can be defined formally and precisely. This paper generalizes previous work on the formal characterization of visualization by, inter alia, Ziemkiewicz and Kosara and allows us to formally distinguish properties of the visualization process that previous work does not.

  6. Modeling in applied sciences a kinetic theory approach

    CERN Document Server

    Pulvirenti, Mario

    2000-01-01

    Modeling complex biological, chemical, and physical systems, in the context of spatially heterogeneous mediums, is a challenging task for scientists and engineers using traditional methods of analysis Modeling in Applied Sciences is a comprehensive survey of modeling large systems using kinetic equations, and in particular the Boltzmann equation and its generalizations An interdisciplinary group of leading authorities carefully develop the foundations of kinetic models and discuss the connections and interactions between model theories, qualitative and computational analysis and real-world applications This book provides a thoroughly accessible and lucid overview of the different aspects, models, computations, and methodology for the kinetic-theory modeling process Topics and Features * Integrated modeling perspective utilized in all chapters * Fluid dynamics of reacting gases * Self-contained introduction to kinetic models * Becker–Doring equations * Nonlinear kinetic models with chemical reactions * Kinet...

  7. The Dalcroze Approach to Music Education: Theory and Applications

    Science.gov (United States)

    Anderson, William Todd

    2012-01-01

    The methods of the Dalcroze approach to music education--eurhythmics, solfege, and improvisation--have had a profound influence on modern music education. In particular, the overt training in kinesthetic abilities, and the assertion that the relationship between music and movement is an intimate one, is at the heart of Dalcroze's approach to…

  8. Mean distribution approach to spin and gauge theories

    CERN Document Server

    Akerlund, Oscar

    2016-01-01

    We formulate self-consistency equations for the distribution of links in spin models and of plaquettes in gauge theories. This improves upon known mean-field, mean-link, and mean-plaquette approximations in such that we self-consistently determine all moments of the considered variable instead of just the first. We give examples in both Abelian and non-Abelian cases.

  9. Investigation of Employee Security Behaviour: A Grounded Theory Approach

    OpenAIRE

    Connolly, Lena; Lang, Michael; Tygar, J.,

    2015-01-01

    Part 5: Security Management and Human Aspects of Security; International audience; At a time of rapid business globalisation, it is necessary to understand employee security behaviour within diverse cultural settings. While general deterrence theory has been extensively used in Behavioural Information Security research with the aim to explain the effect of deterrent factors on employees’ security actions, these studies provide inconsistent and even contradictory findings. Therefore, a further...

  10. Generalised squeezing and information theory approach to quantum entanglement

    Science.gov (United States)

    Vourdas, A.

    1993-01-01

    It is shown that the usual one- and two-mode squeezing are based on reducible representations of the SU(1,1) group. Generalized squeezing is introduced with the use of different SU(1,1) rotations on each irreducible sector. Two-mode squeezing entangles the modes and information theory methods are used to study this entanglement. The entanglement of three modes is also studied with the use of the strong subadditivity property of the entropy.

  11. The Predicate and Theories of Linguistic Communication. A Diachronic Approach

    Directory of Open Access Journals (Sweden)

    Lizica Mihuţ

    2012-01-01

    Full Text Available Theories regarding the predicate and predication are of interest not only as object of research, but also by their history. The present paper targets the latter aspect. The authors investigate the doctrines and schools that focused on the relationship between the predicate, as a grammatical category, and the notion of predication. A first significant survey of the issue appears in the Port-Royal Grammar (1600 where, among the linguistic universals postulated, the category of predicate also appears. John Locke is mentioned as opponent of the theory of linguistic universals and rationalist trends. Worth mentioning is also the work of the founders of linguistics as a science – Fr. Bopp, Rasmus Rask and Jakob Grimm –, as well as that of the so-called neogrammarians, with their immutable phonetic laws. An important section in the economy of the paper is dedicated to Ferdinand de Saussure and his Geneva school. A runner in the footsteps of de Saussure, Eugen Coşeriu’s view regarding language, norm and linguistic communication is then surveyed. The contributions of the Prague linguistic circle, of the Copenhagen school and of the French sociological school (with Antoine Meillet as main representative are also discussed. The paper concludes with the main trends in American linguistics, with emphasis on Noam Chomsky’s generative-transformational grammar and on Ch. Fillmore’s case theory.

  12. Using Rasch Measurement Theory to Examine Two Instructional Approaches for Teaching and Learning of French Grammar

    Science.gov (United States)

    Vogel, Severine P.; Engelhard, George, Jr.

    2011-01-01

    The authors describe a quantitative approach based on Rasch measurement theory for evaluating classroom assessments within the context of foreign language classes. A secondary purpose was to examine the effects of two instructional approaches to teach grammar, a guided inductive and a deductive approach, through the lens of Rasch measurement…

  13. Application of multilevel analysis approach in management theory

    Directory of Open Access Journals (Sweden)

    S. Morteza Ghayour

    2013-12-01

    Full Text Available Any phenomenon can be considered and analyzed in terms of different perspectives. In multilevel theorists view, structure or structures of the studied phenomenon are used to consider or to analyze it, completely. Level of analysis indicates the purpose of a researcher or theorist that is intended to be explained or justified, like individual, group or organizational levels and then they are generalized. Contrary to multilevel approach, the conventional approach of theorizing considers micro level or macro level. It cannot perform a simultaneous micro–macro level analysis. A multilevel approach characterized by inter-level and multilevel organizational view to organizational phenomena is an attempt to expand the boundaries of knowledge and provide a new plan. This study uses documentary studies to analyze the multi-level approach of theorizing, multilevel models and multilevel analysis.

  14. Training teachers to observation: an approach through multiple intelligences theory

    Directory of Open Access Journals (Sweden)

    Nicolini, P.

    2010-11-01

    Full Text Available Observation is a daily practice in scholastic and educational contexts, but it needs to develop into a professional competence in order to be helpful. In fact, to design an educative and didactic plan and to provide useful tools, activities and tasks to their students, teachers and educators need to collect information about learners. For these reasons we’ll built a Web-Observation (Web-Ob application, a tool able to support good practices in observation. In particular, the Web-Ob can provide Multiple Intelligences Theory as a framework through which children’s behaviors and attitudes can be observed, assessed and evaluated.

  15. Theory and observation of auroral substorms: A magnetohydrodynamic approach

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.W.; Xu, B.L.; Samson, J.C.; Rostoker, G. [Univ. of Alberta, Edmonton (Canada)

    1995-01-01

    The authors present a theory to explain the dynamics of auroral substorms, considering the interaction of MHD waves with the coupled magnetosphere/ionosphere system. Their model considers the substorm to originate with the loss of stability of the nightside magnetosphere. This frees a large amount of energy, producing compressional waves. The propagation of these waves, and their interaction with the magnetospheric system then encompass the dynamic aspects of the substorm. They compare their model with information from a storm in Feb 1990 observed by the photometer array of CANOPUS. 39 refs., 12 figs., 2 tabs.

  16. An effective field theory approach to two trapped particles

    OpenAIRE

    Stetcu, I.; Rotureau, J.; Barrett, B.R.; van Kolck, U.

    2010-01-01

    We discuss the problem of two particles interacting via short-range interactions within a harmonic-oscillator trap. The interactions are organized according to their number of derivatives and defined in truncated model spaces made from a bound-state basis. Leading-order (LO) interactions are iterated to all orders, while corrections are treated in perturbation theory. We show explicitly that next-to-LO and next-to-next-to-LO interactions improve convergence as the model space increases. In th...

  17. Random Matrix Theory Approach to Chaotic Coherent Perfect Absorbers

    Science.gov (United States)

    Li, Huanan; Suwunnarat, Suwun; Fleischmann, Ragnar; Schanz, Holger; Kottos, Tsampikos

    2017-01-01

    We employ random matrix theory in order to investigate coherent perfect absorption (CPA) in lossy systems with complex internal dynamics. The loss strength γCPA and energy ECPA, for which a CPA occurs, are expressed in terms of the eigenmodes of the isolated cavity—thus carrying over the information about the chaotic nature of the target—and their coupling to a finite number of scattering channels. Our results are tested against numerical calculations using complex networks of resonators and chaotic graphs as CPA cavities.

  18. Spectral rigidity of vehicular streams (random matrix theory approach)

    Energy Technology Data Exchange (ETDEWEB)

    Krbalek, Milan [Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague (Czech Republic); Seba, Petr [Doppler Institute for Mathematical Physics and Applied Mathematics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague (Czech Republic)

    2009-08-28

    Using a method originally developed for the random matrix theory, we derive an approximate mathematical formula for the number variance {delta}{sub N}(L) describing the rigidity of particle ensembles with a power-law repulsion. The resulting relation is compared with the relevant statistics of the single-vehicle data measured on the Dutch freeway A9. The detected value of the inverse temperature {beta}, which can be identified as a coefficient of the mental strain of the car drivers, is then discussed in detail with the relation to the traffic density {rho} and flow J.

  19. Incorporating Spatial Structures in Ecological Inference: An Information Theory Approach

    Directory of Open Access Journals (Sweden)

    Rosa Bernardini Papalia

    2010-10-01

    Full Text Available This paper introduces an Information Theory-based method for modeling economic aggregates and estimating their sub-group (sub-area decomposition when no individual or sub-group data are available. This method offers a flexible framework for modeling the underlying variation in sub-group indicators, by addressing the spatial dependency problem. A basic ecological inference problem, which allows for spatial heterogeneity and dependence, is presented with the aim of first estimating the model at the aggregate level, and then of employing the estimated coefficients to obtain the sub-group level indicators.

  20. Linear operators and linear systems an analytical approach to control theory

    CERN Document Server

    Partington, Jonathan R

    2004-01-01

    This book presents an introduction to the common ground between operator theory and linear systems theory. Suitable for students of functional analysis, this book also acts as an introduction to a mathematical approach to systems and control for graduate students in departments of applied mathematics or engineering.

  1. Understanding Nature-Related Behaviors among Children through a Theory of Reasoned Action Approach

    Science.gov (United States)

    Gotch, Chad; Hall, Troy

    2004-01-01

    The Theory of Reasoned Action has proven to be a valuable tool for predicting and understanding behavior and, as such, provides a potentially important basis for environmental education program design. This study used a Theory of Reasoned Action approach to examine a unique type of behavior (nature-related activities) and a unique population…

  2. Approaches of the percolation theory and the free energy of dislocation clusters

    Science.gov (United States)

    Ivanskoi, V. A.

    2008-04-01

    The feasibility of describing ordered dislocation networks in crystals in terms of approaches inherent in the percolation theory is investigated theoretically. The free energy of dislocation networks forming clusters is calculated by the methods of the percolation theory using the Ising and Potts models and the Onsager solution.

  3. A practice-theory approach of homeowners’ energy retrofits in four European areas

    DEFF Research Database (Denmark)

    Bartiaux, Franise Bartiaux; Gram-Hanssen, Kirsten; Fonseca, Paula

    2014-01-01

    This article examines whether and how energy retrofitting of owner-occupied dwellings can be understood within the framework of social practice theories. Practice theories help to shift the focus towards more collective approaches and practices, rather than towards individuals. In addressing this...

  4. The TEACH Method: An Interactive Approach for Teaching the Needs-Based Theories Of Motivation

    Science.gov (United States)

    Moorer, Cleamon, Jr.

    2014-01-01

    This paper describes an interactive approach for explaining and teaching the Needs-Based Theories of Motivation. The acronym TEACH stands for Theory, Example, Application, Collaboration, and Having Discussion. This method can help business students to better understand and distinguish the implications of Maslow's Hierarchy of Needs,…

  5. Constrained Perturbation Regularization Approach for Signal Estimation Using Random Matrix Theory

    Science.gov (United States)

    Suliman, Mohamed; Ballal, Tarig; Kammoun, Abla; Al-Naffouri, Tareq Y.

    2016-12-01

    In this supplementary appendix we provide proofs and additional extensive simulations that complement the analysis of the main paper (constrained perturbation regularization approach for signal estimation using random matrix theory).

  6. Minimal flavour violation an effective field theory approach

    CERN Document Server

    D'Ambrosio, G.; Isidori, G.; Strumia, A.

    2002-01-01

    We present a general analysis of extensions of the Standard Model which satisfy the criterion of Minimal Flavour Violation (MFV). We define this general framework by constructing a low-energy effective theory containing the Standard Model fields, with one or two Higgs doublets and, as the only source of SU(3)^5 flavour symmetry breaking, the background values of fields transforming under the flavour group as the ordinary Yukawa couplings. We analyse present bounds on the effective scale of dimension-six operators, which range between 1 and 10 TeV, with the most stringent constraints imposed by B -> X_s gamma. In this class of theories, it is possible to relate predictions for FCNC processes in B physics to those in K physics. We compare the sensitivity of various experimental searches in probing the hypothesis of MFV. Within the two-Higgs-doublet scenario, we develop a general procedure to obtain all tan(beta)-enhanced Higgs-mediated FCNC amplitudes, discussing in particular their impact in B -> l^+l^-, Delta...

  7. A Rolling Element Bearing Fault Diagnosis Approach Based on Multifractal Theory and Gray Relation Theory.

    Science.gov (United States)

    Li, Jingchao; Cao, Yunpeng; Ying, Yulong; Li, Shuying

    2016-01-01

    Bearing failure is one of the dominant causes of failure and breakdowns in rotating machinery, leading to huge economic loss. Aiming at the nonstationary and nonlinear characteristics of bearing vibration signals as well as the complexity of condition-indicating information distribution in the signals, a novel rolling element bearing fault diagnosis method based on multifractal theory and gray relation theory was proposed in the paper. Firstly, a generalized multifractal dimension algorithm was developed to extract the characteristic vectors of fault features from the bearing vibration signals, which can offer more meaningful and distinguishing information reflecting different bearing health status in comparison with conventional single fractal dimension. After feature extraction by multifractal dimensions, an adaptive gray relation algorithm was applied to implement an automated bearing fault pattern recognition. The experimental results show that the proposed method can identify various bearing fault types as well as severities effectively and accurately.

  8. Bare Writing: Comparing Multiliteracies Theory and Nonrepresentational Theory Approaches to a Young Writer Writing

    Science.gov (United States)

    Smith, Amanda R.

    2017-01-01

    In this article, the author argues that new theoretical approaches to literacy are necessary for making visible the affective, embodied, and noncognitive domains of textual meaning making that are often obscured in traditional approaches. To experiment with this argument, the author conducted two analyses on the same data set, using…

  9. New approach to microscopic theory of normal Fermi systems

    Energy Technology Data Exchange (ETDEWEB)

    Khodel, V.A. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii); Shaginyan, V.R. (Leningrad Inst. of Nuclear Physics, Gatchina (USSR))

    1989-08-21

    A new version of the normal Fermi system microscopic theory is suggested. A functional equation for the effective potential R of the quasiparticle interaction is obtained. Methods for the evaluation of R in terms of the particle interaction potential are discussed. It is shown that in the well-known local approximation, the functional equation for R is reduced to an integro-differential one. For a number of model examples for which the Monte Carlo equation of state is known, the local approximation proves to reproduce the Monte Carlo results to an accuracy of a few percent. The method developed is applied to superfluid Fermi systems. The equation for the evaluation of the gap in the single-particle excitation spectrum in terms of the interaction potential R is obtained. (orig.).

  10. Density Functional Approach and Random Matrix Theory in Proteogenesis

    Science.gov (United States)

    Yamanaka, Masanori

    2017-02-01

    We study the energy-level statistics of amino acids by random matrix theory. The molecular orbital and the Kohn-Sham orbital energies are calculated using ab initio and density-functional formalisms for 20 different amino acids. To generate statistical data, we performed a multipoint calculation on 10000 molecular structures produced via a molecular dynamics simulation. For the valence orbitals, the energy-level statistics exhibit repulsion, but the universality in the random matrix cannot be determined. For the unoccupied orbitals, the energy-level statistics indicate an intermediate distribution between the Gaussian orthogonal ensemble and the semi-Poisson statistics for all 20 different amino acids. These amino acids are considered to be in a type of critical state.

  11. Random matrix theory approach to vibrations near the jamming transition

    Science.gov (United States)

    Beltukov, Y. M.

    2015-03-01

    It has been shown that the dynamical matrix M describing harmonic oscillations in granular media can be represented in the form M = AA T, where the rows of the matrix A correspond to the degrees of freedom of individual granules and its columns correspond to elastic contacts between granules. Such a representation of the dynamical matrix makes it possible to estimate the density of vibrational states with the use of the random matrix theory. The found density of vibrational states is approximately constant in a wide frequency range ω- < ω < ω+, which is determined by the ratio of the number of degrees of freedom to the total number of contacts in the system, which is in good agreement with the results of the numerical experiments.

  12. An information theory approach to the density of the earth

    Science.gov (United States)

    Graber, M. A.

    1977-01-01

    Information theory can develop a technique which takes experimentally determined numbers and produces a uniquely specified best density model satisfying those numbers. A model was generated using five numerical parameters: the mass of the earth, its moment of inertia, three zero-node torsional normal modes (L = 2, 8, 26). In order to determine the stability of the solution, six additional densities were generated, in each of which the period of one of the three normal modes was increased or decreased by one standard deviation. The superposition of the seven models is shown. It indicates that current knowledge of the torsional modes is sufficient to specify the density in the upper mantle but that the lower mantle and core will require smaller standard deviations before they can be accurately specified.

  13. Instanton effects in ABJM theory from Fermi gas approach

    Energy Technology Data Exchange (ETDEWEB)

    Hatsuda, Yasuyuki [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst.; Nagoya Univ. (Japan). Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics

    2012-11-19

    We study the instanton effects of the ABJM partition function using the Fermi gas formalism. We compute the exact values of the partition function at the Chern-Simons levels k=1, 2, 3, 4, 6 up to N=44, 20, 18, 16, 14 respectively, and extract non-perturbative corrections from these exact results. Fitting the resulting non-perturbative corrections by their expected forms from the Fermi gas, we determine unknown parameters in them. After separating the oscillating behavior of the grand potential, which originates in the periodicity of the grand partition function, and the worldsheet instanton contribution, which is computed from the topological string theory, we succeed in proposing an analytical expression for the leading D2-instanton correction. Just as the perturbative result, the instanton corrections to the partition function are expressed in terms of the Airy function.

  14. Introduction to Mathematical Systems Theory: A Behavioral Approach

    NARCIS (Netherlands)

    Polderman, Jan W.; Willems, J.C.

    1998-01-01

    This is a book about modelling, analysis, and control of linear time-invariant systems. The book uses what is called the behavioral approach towards mathematical modelling. Thus a system is viewed as a dynamical relation between manifest and latent variables. The emphasis is on dynamical systems

  15. Control approach to Queue Theory | Omolehin | Journal of the ...

    African Journals Online (AJOL)

    The rigid condition for simple queue problem is minimized by considering multiple channels through control approach. The result control problem is solved using Conventional Conjugate Gradient Method and the optimal system performance is obtained. Journal of the Nigerian Association of Mathematical Physics Vol.

  16. Emerging Approaches to Counseling Intervention: Theory, Research, Practice, and Training

    Science.gov (United States)

    Murdock, Nancy L.; Duan, Changming; Nilsson, Johanna E.

    2012-01-01

    This article provides an overview of the major contribution that presents three emerging approaches to counseling: narrative therapy, dialectical behavior therapy, and acceptance and commitment therapy. The three theoretical systems were chosen because they are current, for the most part not addressed in the mainstream counseling psychology…

  17. A Grounded Theory Approach to Physical Activity and Advanced Cancer

    Directory of Open Access Journals (Sweden)

    Sonya S. Lowe

    2015-11-01

    Full Text Available Background: Physical activity has demonstrated benefits in cancer-related fatigue and physical functioning in early-stage cancer patients, however the role of physical activity at the end stage of cancer has not been established. To challenge positivist–empiricist assumptions, I am seeking to develop a new theoretical framework that is grounded in the advanced cancer patient’s experience of activity. Aim: To gain an in-depth understanding of the experience of activity and quality of life in advanced cancer patients. Objectives: (1 To explore the meaning of activity for advanced cancer patients in the context of their day-to-day life, (2 to elicit advanced cancer patients’ perceptions of activity with respect to their quality of life, and (3 to elicit advanced cancer patients’ views of barriers and facilitators to activity in the context of their day-to-day life. Study Design: A two-phase, cross-sectional, qualitative study will be conducted through the postpositivist lens of subtle realism and informed by the principles of grounded theory methods. Study Methods: Advanced cancer patients will be recruited through the outpatient department of a tertiary cancer center. For Phase one, participants will wear an activPAL™ activity monitor and fill out a daily record sheet for seven days duration. For Phase two, the activity monitor output and daily record sheets will be used as qualitative probes for face-to-face, semistructured interviews. Concurrent coding, constant comparative analysis, and theoretical sampling will continue with the aim of achieving as close as possible to theoretical saturation. Ethics and Discussion: Ethical and scientific approval will be obtained by all local institutional review boards prior to study commencement. The findings will generate new mid-level theory about the experience of activity and quality of life in advanced cancer patients and aid in the development of a new theoretical framework for designing

  18. An empirical test of reference price theories using a semiparametric approach

    DEFF Research Database (Denmark)

    Boztug, Yasemin; Hildebrandt, Lutz

      In this paper we estimate and empirically test different behavioral theories of consumer reference price formation. Two major theories are proposed to model the reference price reaction: assimilation contrast theory and prospect theory. We assume that different consumer segments will use...... different reference prices. The study builds on earlier research by Kalyanaram and Little (1994); however, in contrast to their work, we use parametric and semiparametric approaches to detect the structure of the underlying data sets. The different models are tested using a program module in GAUSS...

  19. The study of legal argumentation in argumentation theory and legal theory: approaches and developments

    NARCIS (Netherlands)

    Feteris, E.

    2012-01-01

    This contribution provides an overview of how argumentation theorists, philosophers, legal theorists and legal philosophers approach questions about the standards for the correctness of legal argumentation. Ideas about the analysis and evaluation of legal argumentation, developed by influential

  20. Researching Communication: The Interpretive Approach between Theory and Practice

    OpenAIRE

    Uhan, Samo

    2013-01-01

    A proper understanding of communication research and the way it has been carried out cannot emerge without some consideration of the theoretical backgrounds of the different methodological approaches to communication analysis. In the last few years the most important progress has been made in the field of so called reflexive methodology. According to Alvesson and Sköldberg, the syntagm reflexive methodology (2000) denotes complex relationships between the knowledge-development processes and v...

  1. A new approach to the theory of classical hypergeometric polynomials

    OpenAIRE

    Marco, José Manuel; Parcet, Javier

    2003-01-01

    In this paper we present a unified approach to the spectral analysis of an hypergeometric type operator whose eigenfunctions include the classical orthogonal polynomials. We write the eigenfunctions of this operator by means of a new Taylor formula for operators of Askey-Wilson type. This gives rise to some expressions for the eigenfunctions, which are unknown in such a general setting. Our methods also give a general Rodrigues formula from which several well known formulas of Rodrigues type ...

  2. Mediatization:Critical Theory Approaches to Media Effects

    OpenAIRE

    Hjarvard, Stig

    2017-01-01

    Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exp...

  3. Fractional graph theory a rational approach to the theory of graphs

    CERN Document Server

    Scheinerman, Edward R

    2013-01-01

    A unified treatment of the most important results in the study of fractional graph concepts, this volume explores the various ways in which integer-valued concepts can be modified to derive nonintegral values. It begins with the general fractional theory of hypergraphs and presents in-depth coverage of fundamental and advanced topics. Subjects include fractional matching, fractional coloring, fractional edge coloring, fractional arboricity via matroid methods, and fractional isomorphism. The final chapter examines additional topics such as fractional domination, fractional intersection numbers

  4. An analytic approach to sunset diagrams in chiral perturbation theory: Theory and practice

    Energy Technology Data Exchange (ETDEWEB)

    Ananthanarayan, B.; Ghosh, Shayan [Indian Institute of Science, Centre for High Energy Physics, Karnataka (India); Bijnens, Johan [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden); Hebbar, Aditya [Indian Institute of Science, Centre for High Energy Physics, Karnataka (India); University of Delaware, Department of Physics and Astronomy, Newark, DE (United States)

    2016-12-15

    We demonstrate the use of several code implementations of the Mellin-Barnes method available in the public domain to derive analytic expressions for the sunset diagrams that arise in the two-loop contribution to the pion mass and decay constant in three-flavoured chiral perturbation theory. We also provide results for all possible two mass configurations of the sunset integral, and derive a new one-dimensional integral representation for the one mass sunset integral with arbitrary external momentum. Thoroughly annotated Mathematica notebooks are provided as ancillary files in the Electronic Supplementary Material to this paper, which may serve as pedagogical supplements to the methods described in this paper. (orig.)

  5. New approaches to business cycle theory in current economic science

    Directory of Open Access Journals (Sweden)

    Monica DOBRESCU

    2012-07-01

    Full Text Available In modern economies, current research generally acknowledges that the central issues in macroeconomics are essentially the same as those identified by Keynes in the General Theory of Employment, Interest and Money. One way or the other, economists are trying to address the same macroeconomic issues that they did seven decades ago: How can we account for the different growth rates and various fluctuations observed in national economies? Which are the economic policies most suitable to solve the issues of growth and cyclic behavior? Both the new classicals and the new Keynesians have made considerable progress within their research paradigms: to explain economic fluctuations, the new classicals focus on technological perturbations, the intertemporal substitution of leisure and real business cycles; on the other hand, the new Keynesians speak in terms of monopolistic competition, menu costs or efficiency wages. On the whole, the new classicals believe that the business cycle can best be understood within the market-clearing model, whereas the new keynesians believe that business fluctuations are due to certain market failures of various sorts.The present paper focuses on the main directions of research of the new classical school on the business cycle, given that the theoretical progress in this field has been significant and relevant for economic policy during the past four decades.

  6. Exploring multicollinearity using a random matrix theory approach.

    Science.gov (United States)

    Feher, Kristen; Whelan, James; Müller, Samuel

    2012-01-01

    Clustering of gene expression data is often done with the latent aim of dimension reduction, by finding groups of genes that have a common response to potentially unknown stimuli. However, what is poorly understood to date is the behaviour of a low dimensional signal embedded in high dimensions. This paper introduces a multicollinear model which is based on random matrix theory results, and shows potential for the characterisation of a gene cluster's correlation matrix. This model projects a one dimensional signal into many dimensions and is based on the spiked covariance model, but rather characterises the behaviour of the corresponding correlation matrix. The eigenspectrum of the correlation matrix is empirically examined by simulation, under the addition of noise to the original signal. The simulation results are then used to propose a dimension estimation procedure of clusters from data. Moreover, the simulation results warn against considering pairwise correlations in isolation, as the model provides a mechanism whereby a pair of genes with `low' correlation may simply be due to the interaction of high dimension and noise. Instead, collective information about all the variables is given by the eigenspectrum.

  7. [Migraine and evolutionary theory: paths for a clinical approach].

    Science.gov (United States)

    Alvaro-Gonzalez, L C

    2016-10-01

    Migraine is a very common disorder with a raising incidence. The theory of evolution allow us to explain the emergence of the disorder, due to the advantages that the overreactivity to stimulus provided to ancestral groups of Homo sapiens, and a greater presence of the disorder in modern societies, based in the interactions with external factors. Herein we analyze these points. Design of organisms and their responses to environmental factors emerge to improve survival. Thus pain and headache can be contemplated as homeostatic and adaptative responses. Below 10% of the population has no experience with headache and the migrainous phenotype is quite frequent in secondary headaches and in syndromic forms of migraine. These features can be understood under the next undergrounds: specific neurophysiological data (lack of habituation, sensibilization and low preactivation), genetic features (polygenic disorder with the implication of many gens with a low penetrance, that interact with the environment and are shared with comorbid disorders such as depression and anxiety); and environmental interactions in modern societies (increase in the number of estrogenic cycles and particularly overexposition to stress). A feature that was an evolutionary advantage has been transformed in a highly prevalent and disabling disorder in modern societies. It is the result of the interaction with internal (estrogenic cycles) and external (stress) stimuli. As a consequence, it becomes a mismatch disorder. The effects appear in childhood through epigenetics. Therefore, therapeutic interventions would yield greater benefits if whole populations were included in educative interventions incorporating these aspects.

  8. Sustainable theory of a logistic model - Fisher information approach.

    Science.gov (United States)

    Al-Saffar, Avan; Kim, Eun-Jin

    2017-03-01

    Information theory provides a useful tool to understand the evolution of complex nonlinear systems and their sustainability. In particular, Fisher information has been evoked as a useful measure of sustainability and the variability of dynamical systems including self-organising systems. By utilising Fisher information, we investigate the sustainability of the logistic model for different perturbations in the positive and/or negative feedback. Specifically, we consider different oscillatory modulations in the parameters for positive and negative feedback and investigate their effect on the evolution of the system and Probability Density Functions (PDFs). Depending on the relative time scale of the perturbation to the response time of the system (the linear growth rate), we demonstrate the maintenance of the initial condition for a long time, manifested by a broad bimodal PDF. We present the analysis of Fisher information in different cases and elucidate its implications for the sustainability of population dynamics. We also show that a purely oscillatory growth rate can lead to a finite amplitude solution while self-organisation of these systems can break down with an exponentially growing solution due to the periodic fluctuations in negative feedback. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Analysis of gene translation using a communications theory approach.

    Science.gov (United States)

    Al Bataineh, Mohammad; Huang, Lun; Alonso, Maria; Menhart, Nick; Atkin, Guillermo E

    2010-01-01

    Rapid advances in both genomic data acquisition and computational technology have encouraged the development and use of advanced engineering methods in the field of bioinformatics and computational genomics. Processes in molecular biology can be modeled through the use of these methods. Such processes include identification and annotation of all the functional elements in the genome, including genes and regulatory sequences, which are a fundamental challenge in genomics and computational biology. Since regulatory elements are often short and variable, their identification and discovery using computational algorithms is difficult. However, significant advances have been made in the computational methods for modeling and detection of DNA regulatory elements. This paper proposes a novel use of techniques and principles from communications engineering, coding, and information theory for modeling, identification, and analysis of genomic regulatory elements and biological sequences. The methods proposed are not only able to identify regulatory elements (REs) at their exact locations, but can also "interestingly" distinguish coding from non-coding regions. Therefore, the proposed methods can be utilized to identify genes in the mRNA sequence.

  10. [A Grounded Theory Approach on Nurses' Experience with Workplace Bullying].

    Science.gov (United States)

    Kang, Jiyeon; Yun, Seonyoung

    2016-04-01

    The purpose of this qualitative study was to explore the workplace bullying experience of Korean nurses. Participants were twenty current or former hospital nurses who had experienced workplace bullying. Data were collected through focus group and individual in-depth interviews from February to May, 2015. Theoretical sampling method was applied to the point of theoretical saturation. Transcribed interview contents were analyzed using Corbin and Strauss's grounded theory method. A total of 110 concepts, 48 sub-categories, and 17 categories were identified through the open coding process. As a result of axial coding based on the paradigm model, the central phenomenon of nurses' workplace bullying experience was revealed as 'teaching that has become bullying', and the core category was extracted as 'surviving in love-hate teaching' consisting of a four-step process: confronting reality, trial and error, relationship formation, and settlement. The relationship formation was considered to be the key phase to proceed to the positive settlement phase, and the participants utilized various strategies such as having an open mind, developing human relationships, understanding each other in this phase. The in-depth understanding of the workplace bullying experience has highlighted the importance of effective communication for cultivating desirable human relationships between nurses.

  11. STATE AND ECONOMY IN BOURGEOISIES ECONOMIC THEORIES: A CRITICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Verena Hernández-Pérez

    2016-01-01

    Full Text Available The issue of state-economy relationship has been present throughout the history of bourgeois economic thought. In the bourgeois liberal tradition the distinction between civil society and state has been presented as total and necessary, reserving to the first one the monopoly of economic activity, based on the principle of self-regulating market. From Keynes bourgeois economists were divided into two sides, one side those who still deny the state capacity to intervene right in the economy, and the other those who recognize the need for their participation. This paper proposes a critical approach to the major bourgeois theoretical positions on the relationship state-economy. 

  12. Theory of molecular conductance using a modular approach.

    Science.gov (United States)

    Hsu, Liang-Yan; Rabitz, Herschel

    2016-12-21

    This study probes the correlation between the conductance of a molecular wire (the property of a whole system) and its constituent backbone units (modules). By using a tight-binding Hamiltonian combined with single-particle Green's functions, we develop an approach that enables an estimate of a conductance decay constant in terms of the Hamiltonians of molecular backbone units and the couplings between two nearest-neighbor units in the off-resonant tunneling regime. For demonstration, we examine several representative molecular systems in a framework of the Hückel model (the simplest atomistic-level model). The Hückel model can be reduced to a single-orbital-per-site formulation [A. Nitzan, Annu. Rev. Phys. Chem. 52, 681 (2001)], and each energy level in the single-orbital-per-site picture can be expressed in an explicit form including the synergistic effect of all molecular orbitals of a molecular backbone unit. Based on the proposed approach, we show the correspondence between the complete destructive quantum interference and an infinite injection gap and derive the preconditions of the modified Simmons equation and the rule of intramolecular series circuits.

  13. Blind Measurement Selection: A Random Matrix Theory Approach

    KAUST Repository

    Elkhalil, Khalil

    2016-12-14

    This paper considers the problem of selecting a set of $k$ measurements from $n$ available sensor observations. The selected measurements should minimize a certain error function assessing the error in estimating a certain $m$ dimensional parameter vector. The exhaustive search inspecting each of the $n\\\\choose k$ possible choices would require a very high computational complexity and as such is not practical for large $n$ and $k$. Alternative methods with low complexity have recently been investigated but their main drawbacks are that 1) they require perfect knowledge of the measurement matrix and 2) they need to be applied at the pace of change of the measurement matrix. To overcome these issues, we consider the asymptotic regime in which $k$, $n$ and $m$ grow large at the same pace. Tools from random matrix theory are then used to approximate in closed-form the most important error measures that are commonly used. The asymptotic approximations are then leveraged to select properly $k$ measurements exhibiting low values for the asymptotic error measures. Two heuristic algorithms are proposed: the first one merely consists in applying the convex optimization artifice to the asymptotic error measure. The second algorithm is a low-complexity greedy algorithm that attempts to look for a sufficiently good solution for the original minimization problem. The greedy algorithm can be applied to both the exact and the asymptotic error measures and can be thus implemented in blind and channel-aware fashions. We present two potential applications where the proposed algorithms can be used, namely antenna selection for uplink transmissions in large scale multi-user systems and sensor selection for wireless sensor networks. Numerical results are also presented and sustain the efficiency of the proposed blind methods in reaching the performances of channel-aware algorithms.

  14. Towards a Foundation of Material Approaches in Neo-institutional Theory

    DEFF Research Database (Denmark)

    Cartel, Melodie; Boxenbaum, Eva

    Socio-material approaches of innovation are currently developing fast in neo-institutional theory yet they lack global coherence. As a result, their contribution to the understanding of institutional innovation is fragile. This paper develops a coherent view on socio-material approaches...... of innovation in neo-institutional theory. Drawing on a literature review, we propose that material approaches of institutional innovation focus on the design of institutions. We build on the concept of bricolage to unveil the three activities involved in the design of institutions: crafting, testing...... and evaluating. Eventually, we articulate these findings with existing insights on institutional innovation and develop a multilevel model of institutional innovation....

  15. Nonstationary signals phase-energy approach-theory and simulations

    CERN Document Server

    Klein, R; Braun, S; 10.1006/mssp.2001.1398

    2001-01-01

    Modern time-frequency methods are intended to deal with a variety of nonstationary signals. One specific class, prevalent in the area of rotating machines, is that of harmonic signals of varying frequencies and amplitude. This paper presents a new adaptive phase-energy (APE) approach for time-frequency representation of varying harmonic signals. It is based on the concept of phase (frequency) paths and the instantaneous power spectral density (PSD). It is this path which represents the dynamic behaviour of the system generating the observed signal. The proposed method utilises dynamic filters based on an extended Nyquist theorem, enabling extraction of signal components with optimal signal-to-noise ratio. The APE detects the most energetic harmonic components (frequency paths) in the analysed signal. Tests on simulated signals show the superiority of the APE in resolution and resolving power as compared to STFT and wavelets wave- packet decomposition. The dynamic filters also enable the reconstruction of the ...

  16. A Bayesian approach to estimating variance components within a multivariate generalizability theory framework.

    Science.gov (United States)

    Jiang, Zhehan; Skorupski, William

    2017-12-12

    In many behavioral research areas, multivariate generalizability theory (mG theory) has been typically used to investigate the reliability of certain multidimensional assessments. However, traditional mG-theory estimation-namely, using frequentist approaches-has limits, leading researchers to fail to take full advantage of the information that mG theory can offer regarding the reliability of measurements. Alternatively, Bayesian methods provide more information than frequentist approaches can offer. This article presents instructional guidelines on how to implement mG-theory analyses in a Bayesian framework; in particular, BUGS code is presented to fit commonly seen designs from mG theory, including single-facet designs, two-facet crossed designs, and two-facet nested designs. In addition to concrete examples that are closely related to the selected designs and the corresponding BUGS code, a simulated dataset is provided to demonstrate the utility and advantages of the Bayesian approach. This article is intended to serve as a tutorial reference for applied researchers and methodologists conducting mG-theory studies.

  17. Life Origination and Development Hydrate theory (LOH-Theory): new approaches to the problems of the optimal nutrition and life prolongation

    Science.gov (United States)

    Kadyshevich, E. A.; Ostrovskii, V. E.

    2014-04-01

    Life Origination Hydrate Theory (LOH-Theory) and Mitosis and Replication Hydrate Theory (MRHTheory), both grounded on the notion of honeycomb gas-hydrate structures formation/destruction as the physicochemical phenomenon governing the DNA origination and replication, allow new approaches to the optimal nutrition and life prolongation problems.

  18. Variational approach to gravity field theories from Newton to Einstein and beyond

    CERN Document Server

    Vecchiato, Alberto

    2017-01-01

    This book offers a detailed and stimulating account of the Lagrangian, or variational, approach to general relativity and beyond. The approach more usually adopted when describing general relativity is to introduce the required concepts of differential geometry and derive the field and geodesic equations from purely geometrical properties. Demonstration of the physical meaning then requires the weak field approximation of these equations to recover their Newtonian counterparts. The potential downside of this approach is that it tends to suit the mathematical mind and requires the physicist to study and work in a completely unfamiliar environment. In contrast, the approach to general relativity described in this book will be especially suited to physics students. After an introduction to field theories and the variational approach, individual sections focus on the variational approach in relation to special relativity, general relativity, and alternative theories of gravity. Throughout the text, solved exercis...

  19. Rehabilitation - a new approach. Part two: the underlying theories.

    Science.gov (United States)

    Wade, Derick

    2015-12-01

    This editorial considers how healthcare systems should approach the problems associated with ongoing, persistent symptoms and limitations on a person's ability to undertake activities. It starts from the premise, established in the first editorial, that the current reliance on the biomedical model of health and illness is no longer 'fit for purpose', and is one major cause of current difficulties within the health service. Among other problems, it may lead to the marginalisation of rehabilitation services, especially when resources are limited. This editorial describes and then highlights the implications of the holistic, biopsychosocial model of illness. It also outlines the rehabilitation process, demonstrating its similarity to the process used by medical services, with the primary difference being the centre of attention: disease for medical service, disability for rehabilitation services. The model of rehabilitation emphasises: the importance of being patient-centred and goal-directed in rehabilitation; the need for liaison by the team and learning by the patient; and that the patient needs to be encouraged and enabled to practice wanted activities. © The Author(s) 2015.

  20. Differentiated cell behavior: a multiscale approach using measure theory.

    Science.gov (United States)

    Colombi, Annachiara; Scianna, Marco; Tosin, Andrea

    2015-11-01

    This paper deals with the derivation of a collective model of cell populations out of an individual-based description of the underlying physical particle system. By looking at the spatial distribution of cells in terms of time-evolving measures, rather than at individual cell paths, we obtain an ensemble representation stemming from the phenomenological behavior of the single component cells. In particular, as a key advantage of our approach, the scale of representation of the system, i.e., microscopic/discrete vs. macroscopic/continuous, can be chosen a posteriori according only to the spatial structure given to the aforesaid measures. The paper focuses in particular on the use of different scales based on the specific functions performed by cells. A two-population hybrid system is considered, where cells with a specialized/differentiated phenotype are treated as a discrete population of point masses while unspecialized/undifferentiated cell aggregates are represented by a continuous approximation. Numerical simulations and analytical investigations emphasize the role of some biologically relevant parameters in determining the specific evolution of such a hybrid cell system.

  1. Applications of multi-criteria and game theory approaches manufacturing and logistics

    CERN Document Server

    Hennet, Jean-Claude; Tiwari, Manoj

    2014-01-01

    Aligning the latest practices, innovations and case studies with academic frameworks and theories, the broad area of multi-criteria and game theory applications in manufacturing and logistics is covered in comprehensive details. Part 1 presents ‘multi-criteria applications’ and includes chapters on  logistics with a focus on vehicle routing problems, a multi-objective decision making approach to select the best storage policy and an exploratory study to predict the most important factors that can lead to successful mobile supply chain management adoption for manufacturing firms. Part 2 covers ‘game theory applications’ and encompasses the process of forming a coalition within a corporate network to the problem of integrating inventory and distribution optimization together with game theory to effectively manage supply networks. Providing a forum to investigate, exchange novel ideas and disseminate knowledge covering the broad area of multi-criteria and game theory applications in manufacturing and l...

  2. How device-independent approaches change the meaning of physical theory

    Science.gov (United States)

    Grinbaum, Alexei

    2017-05-01

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

  3. Cognition to Collaboration: User-Centric Approach and Information Behaviour Theories/Models

    OpenAIRE

    Alperen M Aydin

    2016-01-01

    Aim/Purpose: The objective of this paper is to review the vast literature of user-centric in-formation science and inform about the emerging themes in information behaviour science. Background: The paradigmatic shift from system-centric to user-centric approach facilitates research on the cognitive and individual information processing. Various information behaviour theories/models emerged. Methodology: Recent information behaviour theories and models are presented. Features, str...

  4. A wave optics approach to the theory of the Michelson-Morley experiment

    Science.gov (United States)

    Smid, Thomas

    2017-11-01

    A consistent classical wave optics approach to the theory of the Michelson-Morley experiment shows that the original theory as applied by Michelson and Morley and others does not calculate the optical paths of the two beams correctly, primarily because of incorrectly assuming a right angle reflection in the instrument’s reference frame for the transverse beam, but also because of the incorrect assumption of aberration for the wave fronts. The theory presented in this work proves the expected variation of the phase difference when rotating the interferometer to be more than twice as large and also strongly asymmetrical around the zero line.

  5. Applying a theory of change approach to interagency planning in child mental health.

    Science.gov (United States)

    Hernandez, Mario; Hodges, Sharon

    2006-12-01

    This paper describes the use of a theory of change approach to community-based cross-agency service planning for children with serious emotional disturbance and their families. Public agency planners in Contra Costa County, California used the theory of change approach to organize service planning for a population of youth who had been arrested and involved with juvenile probation. The theory of change process described in this paper links community outcomes with planned activities with the assumptions or principles that underlie the community planning efforts. When complete, a theory of change logic model can serve as a guide for implementation, ensuring that community plans for service delivery remain true to their intent. The theory of change development process includes twelve stages and is based on a step-by-step approach. Theory of change logic models establish a context for articulating a community's shared beliefs and prompt local stakeholders to establish logical connections between the population to be served, expected results, and strategies intended to achieve those results.

  6. Clinical decision-making and therapeutic approaches in osteopathy - a qualitative grounded theory study.

    Science.gov (United States)

    Thomson, Oliver P; Petty, Nicola J; Moore, Ann P

    2014-02-01

    There is limited understanding of how osteopaths make decisions in relation to clinical practice. The aim of this research was to construct an explanatory theory of the clinical decision-making and therapeutic approaches of experienced osteopaths in the UK. Twelve UK registered osteopaths participated in this constructivist grounded theory qualitative study. Purposive and theoretical sampling was used to select participants. Data was collected using semi-structured interviews which were audio-recorded and transcribed. As the study approached theoretical sufficiency, participants were observed and video-recorded during a patient appointment, which was followed by a video-prompted interview. Constant comparative analysis was used to analyse and code data. Data analysis resulted in the construction of three qualitatively different therapeutic approaches which characterised participants and their clinical practice, termed; Treater, Communicator and Educator. Participants' therapeutic approach influenced their approach to clinical decision-making, the level of patient involvement, their interaction with patients, and therapeutic goals. Participants' overall conception of practice lay on a continuum ranging from technical rationality to professional artistry, and contributed to their therapeutic approach. A range of factors were identified which influenced participants' conception of practice. The findings indicate that there is variation in osteopaths' therapeutic approaches to practice and clinical decision-making, which are influenced by their overall conception of practice. This study provides the first explanatory theory of the clinical decision-making and therapeutic approaches of osteopaths. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. On the Contributions of a Network Approach to Personality Theory and Research.

    Science.gov (United States)

    Furr, R Michael; Fleeson, William; Anderson, Michelle; Arnold, Elizabeth Mayfield

    2012-07-01

    Understanding personality structure and processes is one of the most fundamental goals in personality psychology. The network approach presented by Cramer et al. represents a useful path toward this goal, and we address two facets of their approach. First, we examine the possibility that it solves the problem of breadth, which has inhibited the integration of trait theory with social cognitive theory. Second, we evaluate the value and usability of their proposed method (qgraph), doing so by conducting idiographic analyses of the symptom structure of Borderline Personality Disorder.

  8. Towards socio-material approaches in simulation-based education: lessons from complexity theory.

    Science.gov (United States)

    Fenwick, Tara; Dahlgren, Madeleine Abrandt

    2015-04-01

    Review studies of simulation-based education (SBE) consistently point out that theory-driven research is lacking. The literature to date is dominated by discourses of fidelity and authenticity - creating the 'real' - with a strong focus on the developing of clinical procedural skills. Little of this writing incorporates the theory and research proliferating in professional studies more broadly, which show how professional learning is embodied, relational and situated in social - material relations. A key concern for medical educators concerns how to better prepare students for the unpredictable and dynamic ambiguity of professional practice; this has stimulated the movement towards socio-material theories in education that address precisely this question. Among the various socio-material theories that are informing new developments in professional education, complexity theory has been of particular importance for medical educators interested in updating current practices. This paper outlines key elements of complexity theory, illustrated with examples from empirical study, to argue its particular relevance for improving SBE. Complexity theory can make visible important material dynamics, and their problematic consequences, that are not often noticed in simulated experiences in medical training. It also offers conceptual tools that can be put to practical use. This paper focuses on concepts of emergence, attunement, disturbance and experimentation. These suggest useful new approaches for designing simulated settings and scenarios, and for effective pedagogies before, during and following simulation sessions. Socio-material approaches such as complexity theory are spreading through research and practice in many aspects of professional education across disciplines. Here, we argue for the transformative potential of complexity theory in medical education using simulation as our focus. Complexity tools open questions about the socio-material contradictions inherent in

  9. Educational Syncretism: Call for a Hyper-modernist Educational Theory Through Proactionary Approach

    Directory of Open Access Journals (Sweden)

    M. Mahmoodi-Shahrebabaki

    2015-12-01

    Full Text Available Presently, the modernist theory of education is losing its momentum and is superseded by the so-called omnipotent postmodernist theories, which, speciously, claim that have proffered solutions to all educational enigmas. Although the postmodernist educational theory is in its ascendancy, especially in the Western world, the tenets of postmodern educational theories, with their over-permissive and desultory blueprints, are not without obvious pitfalls. I argue that, today, with the rapid circulation of information and sweeping transformations in the nature of education-job interactions, we have passed the postmodern era and stepped into a new era called hyper-modernism. Hence, I remind the necessity of formation of syncretism in our educational theorization and I explain that it has to be built upon a proactionary approach since we are, if not within already, one verge of Hyper-modernization.

  10. Newton’s method an updated approach of Kantorovich’s theory

    CERN Document Server

    Ezquerro Fernández, José Antonio

    2017-01-01

    This book shows the importance of studying semilocal convergence in iterative methods through Newton's method and addresses the most important aspects of the Kantorovich's theory including implicated studies. Kantorovich's theory for Newton's method used techniques of functional analysis to prove the semilocal convergence of the method by means of the well-known majorant principle. To gain a deeper understanding of these techniques the authors return to the beginning and present a deep-detailed approach of Kantorovich's theory for Newton's method, where they include old results, for a historical perspective and for comparisons with new results, refine old results, and prove their most relevant results, where alternative approaches leading to new sufficient semilocal convergence criteria for Newton's method are given. The book contains many numerical examples involving nonlinear integral equations, two boundary value problems and systems of nonlinear equations related to numerous physical phenomena. The book i...

  11. A Profile Approach to Self-Determination Theory Motivations at Work

    Science.gov (United States)

    Moran, Christina M.; Diefendorff, James M.; Kim, Tae-Yeol; Liu, Zhi-Qiang

    2012-01-01

    Self-determination theory (SDT) posits the existence of distinct types of motivation (i.e., external, introjected, identified, integrated, and intrinsic). Research on these different types of motivation has typically adopted a variable-centered approach that seeks to understand how each motivation in isolation relates to employee outcomes. We…

  12. Segmented Assimilation Theory and the Life Model: An Integrated Approach to Understanding Immigrants and Their Children

    Science.gov (United States)

    Piedra, Lissette M.; Engstrom, David W.

    2009-01-01

    The life model offers social workers a promising framework to use in assisting immigrant families. However, the complexities of adaptation to a new country may make it difficult for social workers to operate from a purely ecological approach. The authors use segmented assimilation theory to better account for the specificities of the immigrant…

  13. Learner-Centred Pedagogy for Swim Coaching: A Complex Learning Theory-Informed Approach

    Science.gov (United States)

    Light, Richard

    2014-01-01

    While constructivist theories of learning have been widely drawn on to understand and explain learning in games when using game-based approaches their use to inform pedagogy beyond games is limited. In particular, there has been little interest in applying constructivist perspectives on learning to sports in which technique is of prime importance.…

  14. Current Cognitive Distortion Theory and Research: An Internalist Approach to Cognition

    Science.gov (United States)

    Gannon, Theresa A.

    2009-01-01

    This review examines contemporary cognitive distortion theory and research relating to sexual offenders. In particular, this review highlights that researchers--to date--have tended to adopt an internalist approach to sexual offenders' cognition which views offence-supportive cognitive activity as occurring solely within the mind. This review…

  15. Science and Social Practice: Action Research and Activity Theory as Socio-Critical Approaches

    Science.gov (United States)

    Langemeyer, Ines

    2011-01-01

    Action research and activity theory are considered by a number of followers as socio-critical approaches, whereas others do not relate them to social-criticism and use them merely as methods to improve practice. This article searches for general insights in Kurt Lewin's and Lev S. Vygotsky's work into how one proceeds and acts critically. In their…

  16. Using a Contextual Approach in Teaching Evolutionary Theory and Its Attendant Controversy to Undergraduates.

    Science.gov (United States)

    Sheppard, Carol A.; Prischmann, Deirdre A.

    2003-01-01

    Develops activities based on pedagogical research that indicate that student engagement and comprehension are enhanced by methodologies that promote active participation, critical thinking, and an interdisciplinary, contextualist approach to teach evolutionary theory to students in an upper-division, capstone course. Provides critical thinking…

  17. Applying Program Theory-Driven Approach to Design and Evaluate a Teacher Professional Development Program

    Science.gov (United States)

    Lin, Su-ching; Wu, Ming-sui

    2016-01-01

    This study was the first year of a two-year project which applied a program theory-driven approach to evaluating the impact of teachers' professional development interventions on students' learning by using a mix of methods, qualitative inquiry, and quasi-experimental design. The current study was to show the results of using the method of…

  18. The Theory of Planned Behaviour: Predicting Pre-Service Teachers' Teaching Behaviour towards a Constructivist Approach

    Science.gov (United States)

    Wang, Carrie Lijuan; Ha, Amy S.

    2013-01-01

    The two-pronged purpose of this study is to examine factors determining the teaching behaviour of pre-service physical education (PE) teachers towards a constructivist approach, likewise referred to as teaching games for understanding (TGfU). Theory of planned behaviour (TPB) was applied to guide the formulation of research purpose and design. Six…

  19. Experimental validation of the Higher-Order Theory approach for sandwich panels with flexible core materials

    NARCIS (Netherlands)

    Straalen, IJ.J. van

    2000-01-01

    During tthe 1990's the higher-order theory was developed by Frostig to enable detailed stress analyses of sandwich panel structures. To investigate the potentials of this approach experiments are performed on sandwich panels made of thin steel faces and mineral wool or polystyrene core material. A

  20. Using Human Capital Theory to Develop a Policy Approach towards College Student Migration in Illinois

    Science.gov (United States)

    Smith, Ryan Lee

    2006-01-01

    The purpose of this study was to use human capital theory to develop a policy approach towards college student migration in Illinois. A rate of return analysis revealed the social rate of return for college student migrants who return to Illinois and the private rate of return was 15.95%. It was estimated that due to college student migration in…

  1. Using Telephone Conversations to Develop Awareness of Pragmatic Skills: An Activity-Theory-Driven Approach

    Science.gov (United States)

    Xia, Saihua

    2009-01-01

    This paper investigates ESL learners' awareness of pragmatic skills utilizing an activity-theory driven approach to perform an inquiry task into problem-solving service call conversations (PSSCs) between native speakers (NS) and non-native speakers of English (NNSs). Eight high-intermediate ESL learners, from five different language backgrounds,…

  2. Investigating Acceptance toward Mobile Learning to Assist Individual Knowledge Management: Based on Activity Theory Approach

    Science.gov (United States)

    Liaw, Shu-Sheng; Hatala, Marek; Huang, Hsiu-Mei

    2010-01-01

    Mobile devices could facilitate human interaction and access to knowledge resources anytime and anywhere. With respect to wide application possibilities of mobile learning, investigating learners' acceptance towards it is an essential issue. Based on activity theory approach, this research explores positive factors for the acceptance of m-learning…

  3. The user-oriented evaluator's role in formulating a program theory: Using a theory-driven approach

    OpenAIRE

    Christie, CA; Alkin, MC

    2003-01-01

    Program theory plays a prominent role in many evaluations, not only in theory-driven evaluations. This paper presents a case study of the process of developing and refining a program's theory within a user-oriented evaluation. In user-oriented (or utilization-focused) evaluations, primary users can play a role in defining their own program theory. This is different, however, from the typical process by which a program theory is developed when using theory-driven evaluation framework. This cas...

  4. Learning the Theory in Reverse: An Epistemological Approach to Introducing Concept

    Science.gov (United States)

    Mauger, G. S.

    2008-12-01

    One of the great challenges in teaching at all levels is to involve and habituate students to the process of scientific thinking. To fully understand new concepts, students must understand the reasoning that led to their formulation. In this talk I discuss the use of an epistemological approach to introducing new concepts. The approach is based on the idea that both motivation to learn and comprehension are enhanced when students are introduced to the process of creating new theories. A simple example from atmospheric science might be the decrease in atmospheric pressure with height. In the present approach, a discussion is generated in which students attempt to develop a theory that explains this phenomenon. Different theories are critically evaluated until the class centers on a chosen explanation, at which point the accepted scientific explanation is presented. An essential point is that the students need not center on the correct explanation: the emphasis in this approach is the process. More complex examples, such as a discussion of how clouds form, can span multiple lectures and include a number of sub-concepts. Practical considerations are discussed regarding the design and implementation of the method for large survey courses. At its core, the above approach is simply designed to help students internalize the use of the scientific method: observe, explain, and evaluate the explanation. By involving students in this process, the subject matter becomes both accessible and engaging.

  5. Photon control by multi-periodic binary grating waveguides: A coupled-mode theory approach

    DEFF Research Database (Denmark)

    Adam, Jost; Lüder, Hannes; Gerken, Martina

    - taneous control over multiple spectral resonance positions and relative intensities. The experimental findings were theoretically backed up by a rigorous coupled-wave analysis (RCWA) approach, yielding the leaky modes’ complex propagation constants and diffraction efficiencies. This approach, however, can...... only lead to quantitative results outside the device’s band gaps, since only radiative propagation loss is calculated.n order to provide more physical and quantitative insight to grating-induced waveguide losses, we implemented a coupled-mode theory (CMT) approach for the semi-analytical treatment...

  6. A Systematic Knowledge Management Approach Using Object-Oriented Theory in Customer Complaint Management

    Directory of Open Access Journals (Sweden)

    Wusheng Zhang

    2010-12-01

    Full Text Available Research into the effectiveness of customer complaint management has attracted researchers, yet there has been little discussion on customer complaint management in the context of systematic knowledge management approach particularly in the domain of hotel industry. This paper aims to address such gap through the application of object-oriented theory for which the notation of unified modelling language has been adopted for the representation of the concepts, objects, relationships and vocabularies in the domain. The paper used data from forty seven hotel management staff and academics in hospitalitymanagement to investigate lessons learned and best practices in customer complaint management and knowledge management. By providing insights into the potential of a knowledge management approach using object oriented theory, this study advances our understanding on how a knowledge management approach can systematically support the management of hotel customer complaints.

  7. Developing a grounded theory approach: a comparison of Glaser and Strauss.

    Science.gov (United States)

    Heath, Helen; Cowley, Sarah

    2004-02-01

    Novice qualitative researchers are often unsure regarding the analysis of their data and, where grounded theory is chosen, they may be uncertain regarding the differences that now exist between the approaches of Glaser and Strauss, who together first described the method. These two approaches are compared in relation to roots and divergences, role of induction, deduction and verification, ways in which data are coded and the format of generated theory. Personal experience of developing as a ground theorist is used to illustrate some of the key differences. A conclusion is drawn that, rather than debate relative merits of the two approaches, suggests that novice researchers need to select the method that best suits their cognitive style and develop analytic skills through doing research.

  8. The cultural lens approach to evaluating cultural validity of psychological theory.

    Science.gov (United States)

    Hardin, Erin E; Robitschek, Christine; Flores, Lisa Y; Navarro, Rachel L; Ashton, Matthew W

    2014-10-01

    In this article, we introduce the cultural lens approach (CLA), a novel approach to evaluating the extent to which a psychological theory applies across cultural groups. The CLA requires scholars to apply their accumulated knowledge about cultural influences and differences (e.g., independent and interdependent self-construals; Markus & Kitayama, 1991) to the ways in which theoretical propositions are interpreted and operationalized. First we highlight three limitations in existing approaches to cultural validity and the ways in which the CLA addresses these limitations. Next, we articulate the five steps involved in the CLA and apply it to three different theories from social, vocational, and positive psychology to demonstrate its broad utility. In all cases, we highlight how applying the CLA can generate multiple novel testable hypotheses to stimulate future research and to advance knowledge that is culturally sensitive. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  9. Theory-based evaluation of a comprehensive Latino education initiative: an interactive evaluation approach.

    Science.gov (United States)

    Nesman, Teresa M; Batsche, Catherine; Hernandez, Mario

    2007-08-01

    Latino student access to higher education has received significant national attention in recent years. This article describes a theory-based evaluation approach used with ENLACE of Hillsborough, a 5-year project funded by the W.K. Kellogg Foundation for the purpose of increasing Latino student graduation from high school and college. Theory-based evaluation guided planning, implementation as well as evaluation through the process of developing consensus on the Latino population of focus, adoption of culturally appropriate principles and values to guide the project, and identification of strategies to reach, engage, and impact outcomes for Latino students and their families. The approach included interactive development of logic models that focused the scope of interventions and guided evaluation designs for addressing three stages of the initiative. Challenges and opportunities created by the approach are discussed, as well as ways in which the initiative impacted Latino students and collaborating educational institutions.

  10. Contrast and Critique of Two Approaches to Discourse Analysis: Conversation Analysis and Speech Act Theory

    Directory of Open Access Journals (Sweden)

    Nguyen Van Han

    2014-08-01

    Full Text Available Discourse analysis, as Murcia and Olshtain (2000 assume, is a vast study of language in use that extends beyond sentence level, and it involves a more cognitive and social perspective on language use and communication exchanges. Holding a wide range of phenomena about language with society, culture and thought, discourse analysis contains various approaches: speech act, pragmatics, conversation analysis, variation analysis, and critical discourse analysis. Each approach works in its different domain to discourse. For one dimension, it shares the same assumptions or general problems in discourse analysis with the other approaches: for instance, the explanation on how we organize language into units beyond sentence boundaries, or how language is used to convey information about the world, ourselves and human relationships (Schiffrin 1994: viii. For other dimensions, each approach holds its distinctive characteristics contributing to the vastness of discourse analysis. This paper will mainly discuss two approaches to discourse analysis- conversation analysis and speech act theory- and will attempt to point out some similarities as well as contrasting features between the two approaches, followed by a short reflection on their strengths and weaknesses in the essence of each approach. The organizational and discourse features in the exchanges among three teachers at the College of Finance and Customs in Vietnam will be analysed in terms of conversation analysis and speech act theory.

  11. A large deviations approach to limit theory for heavy-tailed time series

    DEFF Research Database (Denmark)

    Mikosch, Thomas Valentin; Wintenberger, Olivier

    2016-01-01

    In this paper we propagate a large deviations approach for proving limit theory for (generally) multivariate time series with heavy tails. We make this notion precise by introducing regularly varying time series. We provide general large deviation results for functionals acting on a sample path...... and vanishing in some neighborhood of the origin. We study a variety of such functionals, including large deviations of random walks, their suprema, the ruin functional, and further derive weak limit theory for maxima, point processes, cluster functionals and the tail empirical process. One of the main results...

  12. A modular approach for item response theory modeling with the R package flirt.

    Science.gov (United States)

    Jeon, Minjeong; Rijmen, Frank

    2016-06-01

    The new R package flirt is introduced for flexible item response theory (IRT) modeling of psychological, educational, and behavior assessment data. flirt integrates a generalized linear and nonlinear mixed modeling framework with graphical model theory. The graphical model framework allows for efficient maximum likelihood estimation. The key feature of flirt is its modular approach to facilitate convenient and flexible model specifications. Researchers can construct customized IRT models by simply selecting various modeling modules, such as parametric forms, number of dimensions, item and person covariates, person groups, link functions, etc. In this paper, we describe major features of flirt and provide examples to illustrate how flirt works in practice.

  13. Truncated Hilbert space approach to the 2d ϕ{sup 4} theory

    Energy Technology Data Exchange (ETDEWEB)

    Bajnok, Zoltan [MTA Lendület Holographic QFT Group, Wigner Research Centre for Physics,Konkoly Thege Miklós út 29-33, Budapest (Hungary); Lajer, Marton [Roland Eötvös University,Pázmány Péter sétány 1/A, Budapest (Hungary)

    2016-10-11

    We apply the massive analogue of the truncated conformal space approach to study the two dimensional ϕ{sup 4} theory in finite volume. We focus on the broken phase and determine the finite size spectrum of the model numerically. We interpret the results in terms of the Bethe-Yang spectrum, from which we extract the infinite volume masses and scattering matrices for various couplings. We compare these results against semiclassical analysis and perturbation theory. We also analyze the critical point of the model and confirm that it is in the Ising universality class.

  14. Towards a general theory of landscape systems: the integration of the geoecological and bioecological approaches

    Directory of Open Access Journals (Sweden)

    Tandarić Neven

    2015-03-01

    Full Text Available Ever since its beginnings, landscape ecology has been developing in two different directions: the bioecological and the geoecological. While the bioecological approach is focused on the relationship between organisms and their abiotic environment, the geoecological approach is based on the relationship between human society and its, primarily abiotic, environment. Therefore, the geoecological approach can be applied in planning human use of the environment in a long term sustainable manner, while the bioecological approach could represent the basis for the planning of conservational and environmental usage. The merging of these two approaches will result in a comprehensive and more holistic landscape ecology, which will thus gain the potential for coordinating interdisciplinary landscape research and a more prominent role in contributing to spatial planning. The merge will also enhance attempts to create a general theory of landscape systems.

  15. Actor Network Theory Approach and its Application in Investigating Agricultural Climate Information System

    Directory of Open Access Journals (Sweden)

    Maryam Sharifzadeh

    2013-03-01

    Full Text Available Actor network theory as a qualitative approach to study complex social factors and process of socio-technical interaction provides new concepts and ideas to understand socio-technical nature of information systems. From the actor network theory viewpoint, agricultural climate information system is a network consisting of actors, actions and information related processes (production, transformation, storage, retrieval, integration, diffusion and utilization, control and management, and system mechanisms (interfaces and networks. Analysis of such systemsembody the identification of basic components and structure of the system (nodes –thedifferent sources of information production, extension, and users, and the understanding of how successfully the system works (interaction and links – in order to promote climate knowledge content and improve system performance to reach agricultural development. The present research attempted to introduce actor network theory as research framework based on network view of agricultural climate information system.

  16. Operator approach to effective medium theory to overcome a breakdown of Maxwell Garnett approximation

    DEFF Research Database (Denmark)

    Popov, Vladislav; Lavrinenko, Andrei; Novitsky, Andrey

    2016-01-01

    We elaborate on an operator approach to effective medium theory for homogenization of the periodic multilayered structures composed of nonmagnetic isotropic materials, which is based on equating the spatial evolution operators for the original structure and its effective alternative. We show...... that the zeroth-, first-, and second-order approximations of the operator effective medium theory correspond to electric dipoles, chirality, and magnetic dipoles plus electric quadrupoles, respectively. We discover that the spatially dispersive bianisotropic effective medium obtained in the second......-order approximation perfectly replaces a multilayered composite and does not suffer from the effective medium approximation breakdown that happened near the critical angle of total internal reflection found previously in the conventional effective medium theory. We establish the criterion of the validity...

  17. Theory of transformation groups I general properties of continuous transformation groups a contemporary approach and translation

    CERN Document Server

    2015-01-01

    This modern translation of Sophus Lie's and Friedrich Engel's “Theorie der Transformationsgruppen Band I” will allow readers to discover the striking conceptual clarity and remarkably systematic organizational thought of the original German text. Volume I presents a comprehensive introduction to the theory and is mainly directed towards the generalization of ideas drawn from the study of examples. The major part of the present volume offers an extremely clear translation of the lucid original. The first four chapters provide not only a translation, but also a contemporary approach, which will help present day readers to familiarize themselves with the concepts at the heart of the subject. The editor's main objective was to encourage a renewed interest in the detailed classification of Lie algebras in dimensions 1, 2 and 3, and to offer access to Sophus Lie's monumental Galois theory of continuous transformation groups, established at the end of the 19th Century. Lie groups are widespread in mathematics, p...

  18. Collective Inclusioning: A Grounded Theory of a Bottom-Up Approach to Innovation and Leading

    Directory of Open Access Journals (Sweden)

    Michal Lysek

    2016-06-01

    Full Text Available This paper is a grounded theory study of how leaders (e.g., entrepreneurs, managers, etc. engage people in challenging undertakings (e.g., innovation that require everyone’s commitment to such a degree that they would have to go beyond what could be reasonably expected in order to succeed. Company leaders sometimes wonder why their employees no longer show the same responsibility towards their work, and why they are more concerned with internal politics than solving customer problems. It is because company leaders no longer apply collective inclusioning to the same extent as they did in the past. Collective inclusioning can be applied in four ways by convincing, afinitizing, goal congruencing, and engaging. It can lead to fostering strong units of people for taking on challenging undertakings. Collective inclusioning is a complementing theory to other strategic management and leading theories. It offers a new perspective on how to implement a bottom-up approach to innovation.

  19. Research approach for forming a new typology of spatial planning theory

    Directory of Open Access Journals (Sweden)

    Bulajić Vladan

    2011-01-01

    Full Text Available What is being suggested in this paper is the research approach for the classification of theoretical contributions in the scientific domain of the spatial planning. Typology is a multidimensional classification, actually it is the framework for the understanding of the subject area, theory and practice, ideas and methodologies. The complex approach is needed to organize the complex and diverse domain of spatial planning theory, which has been shaped by different schools of thought and the influences of the related scientific disciplines. It has been suggested that the research approach becomes the bridge between two cultures, in other words it should be the synthesis of the qualitative and quantitative methods of the typology construction. With the analysis of the existing typologies, which are quantitatively derived, the chosen concepts will be improved and completed due to the computerized statistical analysis of the appropriate bibliometrical data. Moreover, the procedure in the opposite direction will be used, which also connects empiric types with their conceptual counterparts. With that approach, the main aim is to achieve the comprehensive classification scheme, which will take part of the platform for integration of the interdisciplinary approach in the spatial planning domain. That concept of the research belongs to the wider approach that has got the aim that with the scientific innovations and imaginations bring about the solving of the problems and challenges that the spatial planning faces with. The forming of the new typology is the first step in that direction.

  20. The Osmosis of Ideas. The Analysis of the Integrated Approach to IT Management from a Translation Theory perspective

    NARCIS (Netherlands)

    Doorewaard, J.A.C.M.; Bijsterveld, M.J.L. van

    2001-01-01

    Compared to the critical success factors approach, Translation Theory, which is based on Callon/Latour's Actor-network Theory, presents an innovative and inspiring perspective of analyzing a particular management fashion: the so-called Integrated Approach to IT Management. We argue that the

  1. Grounded Theory as an approach to studying students' uses of learning management systems

    Directory of Open Access Journals (Sweden)

    Graham Alsop

    2002-12-01

    Full Text Available This paper presents the first phase of a qualitative study of students' use of a Learning Management System (LMS. A group of students at Kingston University with experience of two different systems were afforded the opportunity to study the relationship between the interface to an LMS and the usability of the system. A 'Grounded Theory' methodology (Glaser and Strauss, 1967 was selected to model the students' framework, as independently as possible from the views of other stakeholders in the LMS. The approach still offered the potential for generalization despite working with a small group of students. In Grounded Theory, data collection and theory-building drive each other reciprocally until a stable 'theory' is reached. In an ideal world this research would be reported at the end of the whole process but it is considered that there is more value in producing less definitive results at this stage rather than a complete theory in one year's time (Oliver, 2000. Even at this stage of the research, it is clear that the students' conception of an LMS is categorically different from that held by the other stakeholders responsible for implementing the system. Identification of these differences and integration of some findings into future developments are critical even if, in the view of the researchers, further development of the 'theory' is required. The findings from this phase validate the use of a grounded approach. They suggest that systemic issues regarding the integration of educational activities with other aspects of everyday life are fundamentally more important than issues in interface design. The students make effective use of remote access facilities but only where this offers a clear comparison with activities that already form part of studying at university. Such comparisons are pragmatic and are seldom defined in terms of 'educational' benefit.

  2. How Decision Support Systems Can Benefit from a Theory of Change Approach.

    Science.gov (United States)

    Allen, Will; Cruz, Jennyffer; Warburton, Bruce

    2017-06-01

    Decision support systems are now mostly computer and internet-based information systems designed to support land managers with complex decision-making. However, there is concern that many environmental and agricultural decision support systems remain underutilized and ineffective. Recent efforts to improve decision support systems use have focused on enhancing stakeholder participation in their development, but a mismatch between stakeholders' expectations and the reality of decision support systems outputs continues to limit uptake. Additional challenges remain in problem-framing and evaluation. We propose using an outcomes-based approach called theory of change in conjunction with decision support systems development to support both wider problem-framing and outcomes-based monitoring and evaluation. The theory of change helps framing by placing the decision support systems within a wider context. It highlights how decision support systems use can "contribute" to long-term outcomes, and helps align decision support systems outputs with these larger goals. We illustrate the benefits of linking decision support systems development and application with a theory of change approach using an example of pest rabbit management in Australia. We develop a theory of change that outlines the activities required to achieve the outcomes desired from an effective rabbit management program, and two decision support systems that contribute to specific aspects of decision making in this wider problem context. Using a theory of change in this way should increase acceptance of the role of decision support systems by end-users, clarify their limitations and, importantly, increase effectiveness of rabbit management. The use of a theory of change should benefit those seeking to improve decision support systems design, use and, evaluation.

  3. How Decision Support Systems Can Benefit from a Theory of Change Approach

    Science.gov (United States)

    Allen, Will; Cruz, Jennyffer; Warburton, Bruce

    2017-06-01

    Decision support systems are now mostly computer and internet-based information systems designed to support land managers with complex decision-making. However, there is concern that many environmental and agricultural decision support systems remain underutilized and ineffective. Recent efforts to improve decision support systems use have focused on enhancing stakeholder participation in their development, but a mismatch between stakeholders' expectations and the reality of decision support systems outputs continues to limit uptake. Additional challenges remain in problem-framing and evaluation. We propose using an outcomes-based approach called theory of change in conjunction with decision support systems development to support both wider problem-framing and outcomes-based monitoring and evaluation. The theory of change helps framing by placing the decision support systems within a wider context. It highlights how decision support systems use can "contribute" to long-term outcomes, and helps align decision support systems outputs with these larger goals. We illustrate the benefits of linking decision support systems development and application with a theory of change approach using an example of pest rabbit management in Australia. We develop a theory of change that outlines the activities required to achieve the outcomes desired from an effective rabbit management program, and two decision support systems that contribute to specific aspects of decision making in this wider problem context. Using a theory of change in this way should increase acceptance of the role of decision support systems by end-users, clarify their limitations and, importantly, increase effectiveness of rabbit management. The use of a theory of change should benefit those seeking to improve decision support systems design, use and, evaluation.

  4. Are theories of perception necessary? A review of Gibson's The Ecological Approach to Visual Perception.

    Science.gov (United States)

    Costall, A P

    1984-01-01

    Representational theories of perception postulate an isolated and autonomous "subject" set apart from its real environment, and then go on to invoke processes of mental representation, construction, or hypothesizing to explain how perception can nevertheless take place. Although James Gibson's most conspicuous contribution has been to challenge representational theory, his ultimate concern was the cognitivism which now prevails in psychology. He was convinced that the so-called cognitive revolution merely perpetuates, and even promotes, many of psychology's oldest mistakes. This review article considers Gibson's final statement of his "ecological" alternative to cognitivism (Gibson, 1979). It is intended not as a complete account of Gibson's alternative, however, but primarily as an appreciation of his critical contribution. Gibson's sustained attempt to counter representational theory served not only to reveal the variety of arguments used in support of this theory, but also to expose the questionable metaphysical assumptions upon which they rest. In concentrating upon Gibson's criticisms of representational theory, therefore, this paper aims to emphasize the point of his alternative scheme and to explain some of the important concerns shared by Gibson's ecological approach and operant psychology.

  5. A new approach for three-phase loads compensation based on the instantaneous reactive power theory

    Energy Technology Data Exchange (ETDEWEB)

    Salmeron, Patricio; Herrera, Reyes S.; Vazquez, Jesus R. [Electrical Engineering Department of the University of Huelva (Spain)

    2008-04-15

    The original instantaneous reactive power theory or p-q theory has been systematically used in the control of active power filters (APFs). When the APF is connected in parallel to a non-linear and unbalanced load, the p-q theory application has allowed a compensation strategy named constant power to be obtained. This means that, after the APF connection, the instantaneous power supplied by the source is constant and it has the same value as the average power consumed by the load. Nevertheless, the use of other compensation strategies is possible: unity power factor or sinusoidal and balanced supply currents, among others. This paper shows that any compensation strategy may be developed into the p-q theory frame. Besides, the paper presents a p-q theory reformulation without using mapping matrices, which makes easier the obtention of the compensation currents. Finally, an exhaustive analysis of practical cases has been carried out at simulation and experimental level through a laboratory prototype which has allowed the proposed approach to be verified. (author)

  6. Density-Gradient Theory: A Macroscopic Approach to Quantum Confinement and Tunneling in Semiconductor Devices

    Science.gov (United States)

    2011-01-01

    heterostructure lasers; in 2D they are the FINFETs and nanowires currently of considerable research interest; and in 3D they are the semiconductor quantum dots...J Comput Electron (2011) 10:65–97 DOI 10.1007/s10825-011-0356-9 Density-gradient theory: a macroscopic approach to quantum confinement and tunneling ...both quantum confinement and quantum tunneling situations are then reviewed. In doing so, particular emphasis is put on understanding the range of va

  7. Theory and approach of information retrievals from electromagnetic scattering and remote sensing

    CERN Document Server

    Jin, Ya-Qiu

    2006-01-01

    Covers several hot topics in current research of electromagnetic scattering, and radiative transfer in complex and random media, polarimetric scattering and SAR imagery technology, data validation and information retrieval from space-borne remote sensing, computational electromagnetics, etc.Including both forward modelling and inverse problems, analytic theory and numerical approachesAn overall summary of the author's works during most recent yearsAlso presents some insight for future research topics.

  8. The relativistic statistical theory and Kaniadakis entropy: an approach through a molecular chaos hypothesis

    OpenAIRE

    Silva, R

    2006-01-01

    We have investigated the proof of the $H$ theorem within a manifestly covariant approach by considering the relativistic statistical theory developed in [G. Kaniadakis, Phy. Rev. E {\\bf 66}, 056125, 2002; {\\it ibid.} {\\bf 72}, 036108, 2005]. As it happens in the nonrelativistic limit, the molecular chaos hypothesis is slightly extended within the Kaniadakis formalism. It is shown that the collisional equilibrium states (null entropy source term) are described by a $\\kappa$ power law generaliz...

  9. A grounded theory approach to the subjective understanding of urban soundscape in Sheffield

    OpenAIRE

    Liu, F.; Kang, J.

    2016-01-01

    The aim of this study is to gain a greater insight into the factors that affect individuals' preferences and understanding of urban soundscapes. Based on a grounded theory approach, with 53 participants in Sheffield, five categories have been revealed for the subjective understanding of soundscape: soundscape definition, soundscape memory, soundscape sentiment, soundscape expectation, and soundscape aesthetics. More specifically, to some extent, the value people place on sounds does not lie i...

  10. Algebraic approach to form factors in the complex sinh-Gordon theory

    Directory of Open Access Journals (Sweden)

    Michael Lashkevich

    2017-01-01

    Full Text Available We study form factors of the quantum complex sinh-Gordon theory in the algebraic approach. In the case of exponential fields the form factors can be obtained from the known form factors of the ZN-symmetric Ising model. The algebraic construction also provides an Ansatz for form factors of descendant operators. We obtain generating functions of such form factors and establish their main properties: the cluster factorization and reflection equations.

  11. How Do the Nurses Cope with Job Stress? A Study with Grounded Theory Approach

    OpenAIRE

    Eslami Akbar, Rasool; Elahi, Nasrin; Mohammadi, Eesa; Fallahi Khoshknab, Masoud

    2017-01-01

    Introduction: Due to the adverse effects of job stress on health of nurses and the importance of coping process of nurses in management of job stress, the present study was carried out with the aim of exploring the experiences of the nurses in order to reveal the original coping process of the nurses in the case of encountering occupational stress. Methods: This qualitative study was conducted with grounded theory approach. Research participants were 15 clinical nurses and four directors of n...

  12. How Do the Nurses Cope with Job Stress? A Study with Grounded Theory Approach

    OpenAIRE

    Rasool Eslami Akbar; Nasrin Elahi; Eesa Mohammadi; Masoud Fallahi Khoshknab

    2017-01-01

    Introduction: Due to the adverse effects of job stress on health of nurses and the importance of coping process of nurses in management of job stress, the present study was carried out with the aim of exploring the experiences of the nurses in order to reveal the original coping process of the nurses in the case of encountering occupational stress. Methods: This qualitative study was conducted with grounded theory approach. Research participants we...

  13. Principles of hyperplasticity an approach to plasticity theory based on thermodynamic principles

    CERN Document Server

    Houlsby, Guy T

    2007-01-01

    A new approach to plasticity theory firmly routed in and compatible with the laws of thermodynamicsProvides a common basis for the formulation and comparison of many existing plasticity modelsIncorporates and introduction to elasticity, plasticity, thermodynamics and their interactionsShows the reader how to formulate constitutive models completely specified by two scalar potential functions from which the incremental responses of any hyperplastic model can be derived.

  14. Excitable systems with noise and delay, with applications to control: renewal theory approach.

    Science.gov (United States)

    Pototsky, Andrey; Janson, Natalia

    2008-03-01

    We present an approach for the analytical treatment of excitable systems with noise-induced dynamics in the presence of time delay. An excitable system is modeled as a bistable system with a time delay, while another delay enters as a control term taken after Pyragas [K. Pyragas, Phys. Lett. A 170, 421 (1992)] as a difference between the current system state and its state tau time units before. This approach combines the elements of renewal theory to estimate the essential features of the resulting stochastic process as functions of the parameters of the controlling term.

  15. Excitable systems with noise and delay, with applications to control: Renewal theory approach

    Science.gov (United States)

    Pototsky, Andrey; Janson, Natalia

    2008-03-01

    We present an approach for the analytical treatment of excitable systems with noise-induced dynamics in the presence of time delay. An excitable system is modeled as a bistable system with a time delay, while another delay enters as a control term taken after Pyragas [K. Pyragas, Phys. Lett. A 170, 421 (1992)] as a difference between the current system state and its state τ time units before. This approach combines the elements of renewal theory to estimate the essential features of the resulting stochastic process as functions of the parameters of the controlling term.

  16. Shared Decision-Making Models Acknowledging an Interprofessional Approach: A Theory Analysis to Inform Nursing Practice.

    Science.gov (United States)

    Lewis, Krystina B; Stacey, Dawn; Squires, Janet E; Carroll, Sandra

    2016-01-01

    Patient engagement in collaboration with health professionals is essential to deliver quality health care. A shared decision-making (SDM) approach requires that patients are involved in decisions regarding their health. SDM is expanding from the patient-physician dyad to incorporate an interprofessional perspective. Conceptual models can be used to better understand theoretical underpinnings for application in clinical practice. The aim of this article was to conduct a theory analysis of conceptual models using an interprofessional approach to SDM and discuss each model's relevance to nursing practice. Walker and Avant's theory analysis approach was used. Three conceptual models were eligible. For all models, the decision-making process was considered iterative. The development process was described for 1 model. All models were logical, parsimonious, and generalizable. One was supported by empirical testing. No model described how partnerships are enacted to achieve interprofessional SDM. Also, there was limited articulation as to how nurses' roles and contributions differ from other team members. This theory analysis highlights the need for a model that explains how partnerships among interprofessional team members are enacted to better understand the operationalization of interprofessional SDM. Implications for nursing practice at all system levels are offered and supported by the 3 models.

  17. Asymmetric Hubbard model within generating functional approach in dynamical mean field theory

    Directory of Open Access Journals (Sweden)

    I.V.Stasyuk

    2006-01-01

    Full Text Available In the paper a new analytic approach to the solution of the effective single-site problem in the dynamical mean field theory is developed. The approach is based on the method of the Kadanoff-Baym generating functional in the form developed by Izyumov et al. It makes it possible to obtain a closed equation in functional derivatives for the irreducible part of the single-site particle Green's function; the solution is constructed iteratively. As an application of the proposed approach the asymmetric Hubbard model (AHM is considered. The inverse irreducible part Ξ-1σ of the single-site Green's function is constructed in the linear approximation with respect to the coherent potential Jσ. Basing on the obtained result, the Green's function of itinerant particles in the Falicov-Kimball limit of AHM is considered, and the decoupling schemes in the equations of motion approach (GH3 approximation, decoupling by Jeschke and Kotliar are analysed.

  18. Learning to perceive in the sensorimotor approach: Piaget's theory of equilibration interpreted dynamically.

    Science.gov (United States)

    Di Paolo, Ezequiel Alejandro; Barandiaran, Xabier E; Beaton, Michael; Buhrmann, Thomas

    2014-01-01

    if understanding is required for perception, how can we learn to perceive something new, something we do not yet understand? According to the sensorimotor approach, perception involves mastery of regular sensorimotor co-variations that depend on the agent and the environment, also known as the "laws" of sensorimotor contingencies (SMCs). In this sense, perception involves enacting relevant sensorimotor skills in each situation. It is important for this proposal that such skills can be learned and refined with experience and yet up to this date, the sensorimotor approach has had no explicit theory of perceptual learning. The situation is made more complex if we acknowledge the open-ended nature of human learning. In this paper we propose Piaget's theory of equilibration as a potential candidate to fulfill this role. This theory highlights the importance of intrinsic sensorimotor norms, in terms of the closure of sensorimotor schemes. It also explains how the equilibration of a sensorimotor organization faced with novelty or breakdowns proceeds by re-shaping pre-existing structures in coupling with dynamical regularities of the world. This way learning to perceive is guided by the equilibration of emerging forms of skillful coping with the world. We demonstrate the compatibility between Piaget's theory and the sensorimotor approach by providing a dynamical formalization of equilibration to give an explicit micro-genetic account of sensorimotor learning and, by extension, of how we learn to perceive. This allows us to draw important lessons in the form of general principles for open-ended sensorimotor learning, including the need for an intrinsic normative evaluation by the agent itself. We also explore implications of our micro-genetic account at the personal level.

  19. Learning to perceive in the sensorimotor approach: Piaget’s theory of equilibration interpreted dynamically

    Science.gov (United States)

    Di Paolo, Ezequiel Alejandro; Barandiaran, Xabier E.; Beaton, Michael; Buhrmann, Thomas

    2014-01-01

    Learning to perceive is faced with a classical paradox: if understanding is required for perception, how can we learn to perceive something new, something we do not yet understand? According to the sensorimotor approach, perception involves mastery of regular sensorimotor co-variations that depend on the agent and the environment, also known as the “laws” of sensorimotor contingencies (SMCs). In this sense, perception involves enacting relevant sensorimotor skills in each situation. It is important for this proposal that such skills can be learned and refined with experience and yet up to this date, the sensorimotor approach has had no explicit theory of perceptual learning. The situation is made more complex if we acknowledge the open-ended nature of human learning. In this paper we propose Piaget’s theory of equilibration as a potential candidate to fulfill this role. This theory highlights the importance of intrinsic sensorimotor norms, in terms of the closure of sensorimotor schemes. It also explains how the equilibration of a sensorimotor organization faced with novelty or breakdowns proceeds by re-shaping pre-existing structures in coupling with dynamical regularities of the world. This way learning to perceive is guided by the equilibration of emerging forms of skillful coping with the world. We demonstrate the compatibility between Piaget’s theory and the sensorimotor approach by providing a dynamical formalization of equilibration to give an explicit micro-genetic account of sensorimotor learning and, by extension, of how we learn to perceive. This allows us to draw important lessons in the form of general principles for open-ended sensorimotor learning, including the need for an intrinsic normative evaluation by the agent itself. We also explore implications of our micro-genetic account at the personal level. PMID:25126065

  20. Learning to perceive in the sensorimotor approach: Piaget's theory of equilibration interpreted dynamically

    Directory of Open Access Journals (Sweden)

    Ezequiel Alejandro Di Paolo

    2014-07-01

    Full Text Available Learning to perceive faces a classical paradox: if understanding is required for perception, how can we learn to perceive something new, something we do not yet understand? According to the sensorimotor approach, perception involves mastery of regular sensorimotor co-variations that depend on the agent and the environment, also known as the ‘laws’ of sensorimotor contingencies. In this sense, perception involves enacting relevant sensorimotor skills in each situation. It is important for this proposal that such skills can be learned and refined with experience and yet up to this date, the sensorimotor approach has had no explicit theory of perceptual learning. The situation is made more complex if we acknowledge the open-ended nature of human learning. In this paper we propose Piaget’s theory of equilibration as a potential candidate to fulfill this role. This theory highlights the importance of intrinsic sensorimotor norms, in terms of the closure of sensorimotor schemes. It also explains how the equilibration of a sensorimotor organization faced with novelty or breakdowns proceeds by re-shaping pre-existing structures in coupling with dynamical regularities of the world. This way learning to perceive is guided by the equilibration of emerging forms of skillful coping with the world. We demonstrate the compatibility between Piaget’s theory and the sensorimotor approach by providing a dynamical formalization of equilibration to give an explicit micro-genetic account of sensorimotor learning and, by extension, of how we learn to perceive. This allows us to draw important lessons in the form of general principles for open-ended sensorimotor learning, including the need for an intrinsic normative evaluation by the agent itself. We also explore implications of our micro-genetic account at the personal level.

  1. The analytical and numerical approaches to the theory of the Moon's librations: Modern analysis and results

    Science.gov (United States)

    Petrova, N.; Zagidullin, A.; Nefedyev, Y.; Kosulin, V.; Andreev, A.

    2017-11-01

    Observing physical librations of celestial bodies and the Moon represents one of the astronomical methods of remotely assessing the internal structure of a celestial body without conducting expensive space experiments. The paper contains a review of recent advances in studying the Moon's structure using various methods of obtaining and applying the lunar physical librations (LPhL) data. In this article LPhL simulation methods of assessing viscoelastic and dissipative properties of the lunar body and lunar core parameters, whose existence has been recently confirmed during the seismic data reprocessing of ;Apollo; space mission, are described. Much attention is paid to physical interpretation of the free librations phenomenon and the methods for its determination. In the paper the practical application of the most accurate analytical LPhL tables (Rambaux and Williams, 2011) is discussed. The tables were built on the basis of complex analytical processing of the residual differences obtained when comparing long-term series of laser observations with the numerical ephemeris DE421. In the paper an efficiency analysis of two approaches to LPhL theory is conducted: the numerical and the analytical ones. It has been shown that in lunar investigation both approaches complement each other in various aspects: the numerical approach provides high accuracy of the theory, which is required for the proper processing of modern observations, the analytical approach allows to comprehend the essence of the phenomena in the lunar rotation, predict and interpret new effects in the observations of lunar body and lunar core parameters.

  2. Theories and models supporting prevention approaches to alcohol problems among youth.

    Science.gov (United States)

    Johnson, E M; Amatetti, S; Funkhouser, J E; Johnson, S

    1988-01-01

    The Alcohol, Drug Abuse, and Mental Health Administration's Office for Substance Abuse Prevention (OSAP) was established to initiate programs to provide prevention and early intervention services for young people, especially high-risk youth. OSAP's starting point was the theories and models that provide the background body of knowledge. The models summarized here guide new prevention efforts and provide a framework for analyzing diverse experiences in the field. The goal has been to develop strategies based on theories and models of prevention that can reverse or prevent adolescent alcohol use. Among the psychosocial models, research in social learning theory is the theoretical basis for prevention efforts using the team approach among individuals, small groups, families, and communities. A prevention technique based on cognitive dissonance theory proposes verbal inoculations to establish or strengthen beliefs and attitudes, helping a young person to resist drinking, which may be in conflict with another, more desirable goal. In the developmental concept adolescence is a period of role confusion out of which the person's identity should emerge. Prevention efforts built on this view seek to help adolescents to form positive identities by achievement as students, athletes, and in community roles. Behavioral intention theory provides a framework for understanding the role of perceived social norms in directing behaviors. In the social development model, prevention programs should create positive peer groups and ensure that the social environment does not give mixed messages. Health behavior theory is the basis for prevention strategies directed toward a person's entire behavior instead of one aspect. The stages of the drug involvement model form the basis for prevention programs providing early intervention directed at the so-called gateway drugs.Among the communications models, the health promotion concept advocates a comprehensive approach in developing health

  3. Theoretical Approach to the Gauge Invariant Linear Response Theories for Ultracold Fermi Gases with Pseudogap

    Directory of Open Access Journals (Sweden)

    Hao Guo

    2015-01-01

    Full Text Available Recent experimental progress allows for exploring some important physical quantities of ultracold Fermi gases, such as the compressibility, spin susceptibility, viscosity, optical conductivity, and spin diffusivity. Theoretically, these quantities can be evaluated from suitable linear response theories. For BCS superfluid, it has been found that the gauge invariant linear response theories can be fully consistent with some stringent consistency constraints. When the theory is generalized to stronger than BCS regime, one may meet serious difficulties to satisfy the gauge invariance conditions. In this paper, we try to construct density and spin linear response theories which are formally gauge invariant for a Fermi gas undergoing BCS-Bose-Einstein Condensation (BEC crossover, especially below the superfluid transition temperature Tc. We adapt a particular t-matrix approach which is close to the G0G formalism to incorporate noncondensed pairing in the normal state. We explicitly show that the fundamental constraints imposed by the Ward identities and Q-limit Ward identity are indeed satisfied.

  4. CEOS Theory: A Comprehensive Approach to Understanding Hard to Maintain Behaviour Change.

    Science.gov (United States)

    Borland, Ron

    2017-03-01

    This paper provides a brief introduction to CEOS theory, a comprehensive theory for understanding hard to maintain behaviour change. The name CEOS is an acronym for Context, Executive, and Operational Systems theory. Behaviour is theorised to be the result of the moment by moment interaction between internal needs (operational processes) in relation to environmental conditions, and for humans this is augmented by goal-directed, executive action which can transcend immediate contingencies. All behaviour is generated by operational processes. Goal-directed behaviours only triumph over contingency-generated competing behaviours when operational processes have been sufficiently activated to support them. Affective force can be generated around executive system (ES) goals from such things as memories of direct experience, vicarious experience, and emotionally charged communications mediated through stories the person generates. This paper makes some refinements and elaborations of the theory, particularly around the role of feelings, and of the importance of stories and scripts for facilitating executive action. It also sketches out how it reconceptualises a range of issues relevant to behaviour change. CEOS provides a framework for understanding the limitations of both informational and environmental approaches to behaviour change, the need for self-regulatory strategies and for taking into account more basic aspects of human functioning. © 2016 The Authors. Applied Psychology: Health and Well-Being published by John Wiley & Sons Ltd on behalf of International Association of Applied Psychology.

  5. Edge theory approach to topological entanglement entropy and other entanglement measures of (2+1) dimensional Chern-Simons theories on a general manifold

    Science.gov (United States)

    Wen, Xueda; Matsuura, Shunji; Ryu, Shinsei

    Topological entanglement entropy of (2+1) dimensional Chern-Simons gauge theories on a general manifold is usually calculated with Witten's method of surgeries and replica trick, in which the spacetime manifold under consideration is very complicated. In this work, we develop an edge theory approach, which greatly simplifies the calculation of topological entanglement entropy of a Chern-Simons theory. Our approach applies to a general manifold with arbitrary genus. The effect of braiding and fusion of Wilson lines can be straightforwardly calculated within our framework. In addition, our method can be generalized to the study of other entanglement measures such as mutual information and entanglement negativity of a topological quantum field theory on a general manifold.

  6. A Hybrid Density Functional Theory/Molecular Mechanics Approach for Linear Response Properties in Heterogeneous Environments.

    Science.gov (United States)

    Rinkevicius, Zilvinas; Li, Xin; Sandberg, Jaime A R; Mikkelsen, Kurt V; Ågren, Hans

    2014-03-11

    We introduce a density functional theory/molecular mechanical approach for computation of linear response properties of molecules in heterogeneous environments, such as metal surfaces or nanoparticles embedded in solvents. The heterogeneous embedding environment, consisting from metallic and nonmetallic parts, is described by combined force fields, where conventional force fields are used for the nonmetallic part and capacitance-polarization-based force fields are used for the metallic part. The presented approach enables studies of properties and spectra of systems embedded in or placed at arbitrary shaped metallic surfaces, clusters, or nanoparticles. The capability and performance of the proposed approach is illustrated by sample calculations of optical absorption spectra of thymidine absorbed on gold surfaces in an aqueous environment, where we study how different organizations of the gold surface and how the combined, nonadditive effect of the two environments is reflected in the optical absorption spectrum.

  7. Fuzzy Saturated Output Feedback Tracking Control for Robot Manipulators: A Singular Perturbation Theory Based Approach

    Directory of Open Access Journals (Sweden)

    Huashan Liu

    2011-09-01

    Full Text Available To deal with the problem of the output feedback tracking (OFT control with bounded torque inputs of robot manipulators, we propose a generalized fuzzy saturated OFT controller based on singular perturbation theory. First, considering the fact that the output toque of joint actuators is limited, a general expression for a class of saturation functions is given to be applied in the control law. Second, to carry out the whole closed-loop control with only position measurements, linear and nonlinear filters are optionally involved to generate a pseudo signal to surrogate the actual velocity tracking error. As a third contribution, a fuzzy regulator is added to obtain a self-tuning performance in tackling the disturbances. Moreover, an explicit but strict stability proof of the system based on the stability theory of singularly perturbed systems is presented. Finally, numerical simulations on several sample controllers are implemented to verify the effectiveness of the proposed approach.

  8. Designing “Theory of Machines and Mechanisms” course on Project Based Learning approach

    DEFF Research Database (Denmark)

    Shinde, Vikas

    2013-01-01

    Theory of Machines and Mechanisms course is one of the essential courses of Mechanical Engineering undergraduate curriculum practiced at Indian Institute. Previously, this course was taught by traditional instruction based pedagogy. In order to achieve profession specific skills demanded by the i......Theory of Machines and Mechanisms course is one of the essential courses of Mechanical Engineering undergraduate curriculum practiced at Indian Institute. Previously, this course was taught by traditional instruction based pedagogy. In order to achieve profession specific skills demanded...... by the industry and the learning outcomes specified by the National Board of Accreditation (NBA), India; this course is restructured on Project Based Learning approach. A mini project is designed to suit course objectives. An objective of this paper is to discuss the rationale of this course design...

  9. Fuzzy Saturated Output Feedback Tracking Control for Robot Manipulators: A Singular Perturbation Theory Based Approach

    Directory of Open Access Journals (Sweden)

    Huashan Liu

    2011-09-01

    Full Text Available To deal with the problem of the output feedback tracking (OFT control with bounded torque inputs of robot manipulators, we propose a generalized fuzzy saturated OFT controller based on singular perturbation theory. First, considering the fact that the output toque of joint actuators is limited, a general expression for a class of saturation functions is given to be applied in the control law. Second, to carry out the whole closed‐loop control with only position measurements, linear and nonlinear filters are optionally involved to generate a pseudo signal to surrogate the actual velocity tracking error. As a third contribution, a fuzzy regulator is added to obtain a self‐tuning performance in tackling the disturbances. Moreover, an explicit but strict stability proof of the system based on the stability theory of singularly perturbed systems is presented. Finally, numerical simulations on several sample controllers are implemented to verify the effectiveness of the proposed approach.

  10. Bound-state field-theory approach to proton-structure effects in muonic hydrogen

    Science.gov (United States)

    Mohr, Peter J.; Griffith, J.; Sapirstein, J.

    2013-05-01

    A bound-state field-theory approach to muonic hydrogen is set up using a variant of the Furry representation in which the lowest-order Hamiltonian describes a muon in the presence of a point Coulomb field, but the origin of the binding field is taken to be three charged quarks in the proton, which are modeled as Dirac particles that move freely within a spherical well. Bound-state field-theory techniques are used to evaluate one- and two-photon effects. Particular attention is paid to two-photon-exchange diagrams, which include the effect of proton polarizability. In addition, the modification of the electromagnetic self energy of the proton by the electric field of the muon is examined. Finally, the model is used to carry out a calculation of the static electric polarizability of the proton.

  11. The social reality of the imaginary audience: a grounded theory approach.

    Science.gov (United States)

    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.

  12. Valence evaluation with approaching or withdrawing cues: directly testing valence-arousal conflict theory.

    Science.gov (United States)

    Wang, Yan Mei; Li, Ting; Li, Lin

    2017-07-19

    The valence-arousal conflict theory assumes that both valence and arousal will trigger approaching or withdrawing tendencies. It also predicts that the speed of processing emotional stimuli will depend on whether valence and arousal trigger conflicting or congruent motivational tendencies. However, most previous studies have provided evidence of the interaction between valence and arousal only, and have not provided direct proof of the interactive links between valence, arousal and motivational tendencies. The present study provides direct evidence for the relationship between approach-withdrawal tendencies and the valence-arousal conflict. In an empirical test, participants were instructed to judge the valence of emotional words after visual-spatial cues that appeared to be either approaching or withdrawing from participants. A three-way interaction (valence, arousal, and approach-withdrawal tendency) was observed such that the response time was shorter if participants responded to a negative high-arousal stimulus after a withdrawing cue, or to a positive low-arousal stimulus after an approaching cue. These findings suggest that the approach-withdrawal tendency indeed plays a crucial role in valence-arousal conflict, and that the effect depends on the congruency of valence, arousal and tendency at an early stage of processing.

  13. Information fusion-based approach for studying influence on Twitter using belief theory.

    Science.gov (United States)

    Azaza, Lobna; Kirgizov, Sergey; Savonnet, Marinette; Leclercq, Éric; Gastineau, Nicolas; Faiz, Rim

    2016-01-01

    Influence in Twitter has become recently a hot research topic, since this micro-blogging service is widely used to share and disseminate information. Some users are more able than others to influence and persuade peers. Thus, studying most influential users leads to reach a large-scale information diffusion area, something very useful in marketing or political campaigns. In this study, we propose a new approach for multi-level influence assessment on multi-relational networks, such as Twitter . We define a social graph to model the relationships between users as a multiplex graph where users are represented by nodes, and links model the different relations between them (e.g., retweets , mentions , and replies ). We explore how relations between nodes in this graph could reveal about the influence degree and propose a generic computational model to assess influence degree of a certain node. This is based on the conjunctive combination rule from the belief functions theory to combine different types of relations. We experiment the proposed method on a large amount of data gathered from Twitter during the European Elections 2014 and deduce top influential candidates. The results show that our model is flexible enough to to consider multiple interactions combination according to social scientists needs or requirements and that the numerical results of the belief theory are accurate. We also evaluate the approach over the CLEF RepLab 2014 data set and show that our approach leads to quite interesting results.

  14. Relationships between Pre-Service Teachers' Conceptions of Assessment, Approaches to Instruction, and Assessment: An Achievement Goal Theory Perspective

    Science.gov (United States)

    Daniels, Lia M.; Poth, Cheryl A.

    2017-01-01

    The purpose of this paper was to examine the relationships between pre-service teachers' conceptions of assessment and their intended approaches to classroom instruction and assessment. We operationalised approaches to instruction and assessment according to Achievement Goal Theory, postulating that pre-service teachers approach instruction and…

  15. IMPROVING TRUST THROUGH ETHICAL LEADERSHIP: MOVING BEYOND THE SOCIAL LEARNING THEORY TO A HISTORICAL LEARNING APPROACH

    Directory of Open Access Journals (Sweden)

    Omoregie Charles Osifo

    2016-12-01

    Full Text Available The complex nature of trust and its evolving relative concepts require a more idealistic and simpler review. Ethical leadership is related to trust, honesty, transparency, compassion, empathy, results-orientedness, and many other behavioral attributes. Ethical leadership and good leadership are the same, because they represent practicing what one preaches or showing a way to the accomplishment of set goals. The outcomes and findings of many research papers on trust and ethical leadership report positive correlations between ethical leadership and trust. Improving trust from different rational standpoints requires moving and looking beyond the popular theoretical framework through which most results are derived in order to create a new thinking perspective. Social learning theory strongly emphasizes modelling while the new historical learning approach, proposed by the author, is defined as an approach that creates unique historical awareness among individuals, groups, institutions, societies, and nations to use previous experience(s or occurrence(s as a guide in developing positive opinion(s and framework(s in order to tackle the problems and issues of today and tomorrow. Social learning theory is seen as limited from the perspectives of balancing the equation between leadership and trust, the non-compatibility of the values of different generations at work, and other approaches and methods that support the historical approach. This paper is argumentative, adopts a writer´s perspective, and employs a logical analysis of the literature. The main contention is that a historical learning approach can inform an independent-learning to improve trust and its relatives (e.g. motivation and performance, because independent learning can positively shape the value of integrity, which is an integral part of ethical leadership. Historical learning can positively shape leadership in every perspective, because good leadership can develop based on history and

  16. From miasmas to germs: a historical approach to theories of infectious disease transmission.

    Science.gov (United States)

    Karamanou, Marianna; Panayiotakopoulos, George; Tsoucalas, Gregory; Kousoulis, Antonis A; Androutsos, George

    2012-03-01

    From miasma to germ theory we trace the evolution of conceptions in infectious disease transmission. Starting from the unproved theories of contagiousness we move on to miasma theory, contagion theory and spontaneous generation theory up to the revolutionary germ theory of disease transmission.

  17. The Theory of Money and Financial Institutions: A Summary of a Game Theoretic Approach

    OpenAIRE

    Martin Shubik

    2006-01-01

    A game theoretic approach to the theory of money and financial institution is given utilizing both the strategic and coalitional forms for describing the economy. The economy is first modeled as a strategic market game, then the strategic form is used to calculate several cooperative forms that differ from each other in their utilization of money and credit and their treatment of threats. It is shown that there are natural upper and lower bounds to the monetary needs of an economy, but even i...

  18. Scalable numerical approach for the steady-state ab initio laser theory

    Science.gov (United States)

    Esterhazy, S.; Liu, D.; Liertzer, M.; Cerjan, A.; Ge, L.; Makris, K. G.; Stone, A. D.; Melenk, J. M.; Johnson, S. G.; Rotter, S.

    2014-08-01

    We present an efficient and flexible method for solving the non-linear lasing equations of the steady-state ab initio laser theory. Our strategy is to solve the underlying system of partial differential equations directly, without the need of setting up a parametrized basis of constant flux states. We validate this approach in one-dimensional as well as in cylindrical systems, and demonstrate its scalability to full-vector three-dimensional calculations in photonic-crystal slabs. Our method paves the way for efficient and accurate simulations of microlasers which were previously inaccessible.

  19. Worldline approach to quantum field theories on flat manifolds with boundaries

    OpenAIRE

    Bastianelli, Fiorenzo; Corradini, Olindo; Pisani, Pablo A. G.

    2006-01-01

    We study a worldline approach to quantum field theories on flat manifolds with boundaries. We consider the concrete case of a scalar field propagating on R_+ x R^{D-1} which leads us to study the associated heat kernel through a one dimensional (worldline) path integral. To calculate the latter we map it onto an auxiliary path integral on the full R^D using an image charge. The main technical difficulty lies in the fact that a smooth potential on R_+ x R^{D-1} extends to a potential which gen...

  20. BOOK REVIEW E-LEARNING SYSTEMS, ENVIRONMENTS AND APPROACHES Theory and Implementation

    Directory of Open Access Journals (Sweden)

    Recep ONDER

    2016-10-01

    Full Text Available E-learning systems have been attainable for years with their different options and flexibilities. These systems provide opportunities like flexible structures with respect to time and space, personalization of learning and sharing of adaptable learning experience. With these features, e-learning systems gain places in the education environments. In this context, we reviewed the book “E-Learning Systems, Environments and Approaches: Theory and Implementation” edited by Pedro Isaías, J. Michael Spector, Dirk Ifenthaler and Demetrios G. Sampson (2015 which included theoretical knowledge on the e-learning technologies and contributed to the literature with experimental implementation examples in the education environments.

  1. SAFE MOVEMENT OF HAZARDOUS MATERIALS THROUGH HEURISTIC HYBRID APPROACH: TABU SEARCH AND GAME THEORY APLICATION

    Directory of Open Access Journals (Sweden)

    Hakan ASLAN

    2008-03-01

    Full Text Available The safe movement of hazardous materials is receiving increased attention due to growing environmental awareness of the potential health affects of a release causing incident. A novel approach developed in this paper through a game theory interpretation provides a risk-averse solution to the hazardous materials transportation problem. The dispatcher minimizes the expected maximum disutility subject to worst possible set of link failure probabilities, assuming that one link in the network fails. The expected cost at the Nash equilibrium is a useful measure to evaluate the routing strategies for the safe movement of hazardous materials.

  2. A Dynamic Density Functional Theory Approach to Diffusion in White Dwarfs and Neutron Star Envelopes

    Science.gov (United States)

    Diaw, A.; Murillo, M. S.

    2016-09-01

    We develop a multicomponent hydrodynamic model based on moments of the Born-Bogolyubov-Green-Kirkwood-Yvon hierarchy equations for physical conditions relevant to astrophysical plasmas. These equations incorporate strong correlations through a density functional theory closure, while transport enters through a relaxation approximation. This approach enables the introduction of Coulomb coupling correction terms into the standard Burgers equations. The diffusive currents for these strongly coupled plasmas is self-consistently derived. The settling of impurities and its impact on cooling can be greatly affected by strong Coulomb coupling, which we show can be quantified using the direct correlation function.

  3. Realizing an Optimization Approach Inspired from Piaget’s Theory on Cognitive Development

    Directory of Open Access Journals (Sweden)

    Utku Kose

    2015-09-01

    Full Text Available The objective of this paper is to introduce an artificial intelligence based optimization approach, which is inspired from Piaget’s theory on cognitive development. The approach has been designed according to essential processes that an individual may experience while learning something new or improving his / her knowledge. These processes are associated with the Piaget’s ideas on an individual’s cognitive development. The approach expressed in this paper is a simple algorithm employing swarm intelligence oriented tasks in order to overcome single-objective optimization problems. For evaluating effectiveness of this early version of the algorithm, test operations have been done via some benchmark functions. The obtained results show that the approach / algorithm can be an alternative to the literature in terms of single-objective optimization.The authors have suggested the name: Cognitive Development Optimization Algorithm (CoDOA for the related intelligent optimization approach.

  4. Facilitating progress in health behaviour theory development and modification: the reasoned action approach as a case study.

    Science.gov (United States)

    Head, Katharine J; Noar, Seth M

    2014-01-01

    This paper explores the question: what are barriers to health behaviour theory development and modification, and what potential solutions can be proposed? Using the reasoned action approach (RAA) as a case study, four areas of theory development were examined: (1) the theoretical domain of a theory; (2) tension between generalisability and utility, (3) criteria for adding/removing variables in a theory, and (4) organisational tracking of theoretical developments and formal changes to theory. Based on a discussion of these four issues, recommendations for theory development are presented, including: (1) the theoretical domain for theories such as RAA should be clarified; (2) when there is tension between generalisability and utility, utility should be given preference given the applied nature of the health behaviour field; (3) variables should be formally removed/amended/added to a theory based on their performance across multiple studies and (4) organisations and researchers with a stake in particular health areas may be best suited for tracking the literature on behaviour-specific theories and making refinements to theory, based on a consensus approach. Overall, enhancing research in this area can provide important insights for more accurately understanding health behaviours and thus producing work that leads to more effective health behaviour change interventions.

  5. An approach to children's smoking behavior using social cognitive learning theory.

    Science.gov (United States)

    Bektas, Murat; Ozturk, Candan; Armstrong, Merry

    2010-01-01

    This review article discusses the theoretical principles of social cognitive learning theory and children's risk-taking behavior of cigarette smoking, along with preventive initiatives. Social cognitive learning theorists examine the behavior of initiating and sustained smoking using a social systems approach. The authors discuss the reciprocal determinism aspect of the theory as applied to the importance of individual factors, and environment and behavioral interactions that influence smoking behavior. Included is the concept of vicarious capability that suggests that smoking behavior is determined in response to and interaction with feedback provided by the environment. The principle of self-regulatory capability asserts that people have control over their own behavior and thus that behavior change is possible. The principle of self-efficacy proposes that high level of self-efficacy of an individual may decrease the behavior of attempting to or continuing to smoke. Examples of initiatives to be undertaken in order to prevent smoking in accordance with social cognitive learning theory are presented at the end of each principle.

  6. Cognitive effects of mindfulness training: Results of a pilot study based on a theory driven approach

    Directory of Open Access Journals (Sweden)

    Lena Wimmer

    2016-07-01

    Full Text Available The present paper reports a pilot study which tested cognitive effects of mindfulness practice in a theory-driven approach. Thirty-four fifth graders received either a mindfulness training which was based on the mindfulness-based stress reduction approach (experimental group, a concentration training (active control group or no treatment (passive control group. Based on the operational definition of mindfulness by Bishop et al. (2004, effects on sustained attention, cognitive flexibility, cognitive inhibition and data-driven as opposed to schema-based information processing were predicted. These abilities were assessed in a pre-post design by means of a vigilance test, a reversible figures test, the Wisconsin Card Sorting Test, a Stroop test, a visual search task, and a recognition task of prototypical faces. Results suggest that the mindfulness training specifically improved cognitive inhibition and data-driven information processing.

  7. Coalition of distributed generation units to virtual power players - a game theory approach

    DEFF Research Database (Denmark)

    Morais, Hugo; Sousa, Tiago M; Santos, Gabriel

    2015-01-01

    and the existence of new management players such as several types of aggregators. This paper proposes a methodology to facilitate the coalition between distributed generation units originating Virtual Power Players (VPP) considering a game theory approach. The proposed approach consists in the analysis......Smart Grids (SGs) have emerged as the new paradigm for power system operation and management, being designed to include large amounts of distributed energy resources. This new paradigm requires new Energy Resource Management (ERM) methodologies considering different operation strategies...... of the classifications that were attributed by each VPP to the distributed generation units, as well as in the analysis of the previous established contracts by each player. The proposed classification model is based in fourteen parameters including technical, economical and behavioural ones. Depending of the VPP...

  8. The quasilinear theory in the approach of long-range systems to quasi-stationary states

    Science.gov (United States)

    Campa, Alessandro; Chavanis, Pierre-Henri

    2017-05-01

    We develop a quasilinear theory of the Vlasov equation in order to describe the approach of systems with long-range interactions to quasi-stationary states. The quasilinear theory is based on the assumption that, although the initial distribution is not Vlasov stable, nevertheless its evolution towards a Vlasov stable stationary state is such that it is always only slightly inhomogeneous. We derive a diffusion equation governing the evolution of the velocity distribution of the system towards a steady state. This steady state is expected to correspond to the space-averaged quasi-stationary distribution function reached by the Vlasov equation as a result of a collisionless relaxation. We compare the prediction of the quasilinear theory to direct numerical simulations of the Hamiltonian mean field model, starting from an unstable spatially homogeneous distribution, either Gaussian or semi-elliptical. In the Gaussian case, we find that the quasilinear theory works reasonably well for weakly unstable initial conditions (i.e. close to the critical energy ε_c=3/4=0.75 ) and that it is able to predict the energy ε_t≃ 0.735 marking the effective out-of-equilibrium phase transition between unmagnetized and magnetized quasi-stationary states found in the numerical simulations. Similarly, the quasilinear theory works well for energies close to the instability threshold of the semi-elliptical case ε^*c =5/8=0.625 , and it predicts an effective out-of-equilibrium transition at εt≃ 0.619 . In both situations, the quasilinear theory works less well at energies lower than the out-of-equilibrium transition, the disagreement with the numerical simulations increasing with decreasing energy. In that case, we observe, in agreement with our previous numerical study (Campa and Chavanis 2013 Eur. Phys. J. B 86 170), that the quasi-stationary states are remarkably well fitted by polytropic distributions (Tsallis distributions) with index n  =  2 (Gaussian case) or n

  9. Dissemination of a theory-based online bone health program: Two intervention approaches.

    Science.gov (United States)

    Nahm, Eun-Shim; Resnick, Barbara; Bellantoni, Michele; Zhu, Shijun; Brown, Clayton; Brennan, Patricia F; Charters, Kathleen; Brown, Jeanine; Rietschel, Matthew; Pinna, Joanne; An, Minjeong; Park, Bu Kyung; Plummer, Lisa

    2015-06-01

    With the increasing nationwide emphasis on eHealth, there has been a rapid growth in the use of the Internet to deliver health promotion interventions. Although there has been a great deal of research in this field, little information is available regarding the methodologies to develop and implement effective online interventions. This article describes two social cognitive theory-based online health behavior interventions used in a large-scale dissemination study (N = 866), their implementation processes, and the lessons learned during the implementation processes. The two interventions were a short-term (8-week) intensive online Bone Power program and a longer term (12-month) Bone Power Plus program, including the Bone Power program followed by a 10-month online booster intervention (biweekly eHealth newsletters). This study used a small-group approach (32 intervention groups), and to effectively manage those groups, an eLearning management program was used as an upper layer of the Web intervention. Both interventions were implemented successfully with high retention rates (80.7% at 18 months). The theory-based approaches and the online infrastructure used in this study showed a promising potential as an effective platform for online behavior studies. Further replication studies with different samples and settings are needed to validate the utility of this intervention structure. © The Author(s) 2013.

  10. Towards a category theory approach to analogy: Analyzing re-representation and acquisition of numerical knowledge.

    Directory of Open Access Journals (Sweden)

    Jairo A Navarrete

    2017-08-01

    Full Text Available Category Theory, a branch of mathematics, has shown promise as a modeling framework for higher-level cognition. We introduce an algebraic model for analogy that uses the language of category theory to explore analogy-related cognitive phenomena. To illustrate the potential of this approach, we use this model to explore three objects of study in cognitive literature. First, (a we use commutative diagrams to analyze an effect of playing particular educational board games on the learning of numbers. Second, (b we employ a notion called coequalizer as a formal model of re-representation that explains a property of computational models of analogy called "flexibility" whereby non-similar representational elements are considered matches and placed in structural correspondence. Finally, (c we build a formal learning model which shows that re-representation, language processing and analogy making can explain the acquisition of knowledge of rational numbers. These objects of study provide a picture of acquisition of numerical knowledge that is compatible with empirical evidence and offers insights on possible connections between notions such as relational knowledge, analogy, learning, conceptual knowledge, re-representation and procedural knowledge. This suggests that the approach presented here facilitates mathematical modeling of cognition and provides novel ways to think about analogy-related cognitive phenomena.

  11. Towards a category theory approach to analogy: Analyzing re-representation and acquisition of numerical knowledge.

    Science.gov (United States)

    Navarrete, Jairo A; Dartnell, Pablo

    2017-08-01

    Category Theory, a branch of mathematics, has shown promise as a modeling framework for higher-level cognition. We introduce an algebraic model for analogy that uses the language of category theory to explore analogy-related cognitive phenomena. To illustrate the potential of this approach, we use this model to explore three objects of study in cognitive literature. First, (a) we use commutative diagrams to analyze an effect of playing particular educational board games on the learning of numbers. Second, (b) we employ a notion called coequalizer as a formal model of re-representation that explains a property of computational models of analogy called "flexibility" whereby non-similar representational elements are considered matches and placed in structural correspondence. Finally, (c) we build a formal learning model which shows that re-representation, language processing and analogy making can explain the acquisition of knowledge of rational numbers. These objects of study provide a picture of acquisition of numerical knowledge that is compatible with empirical evidence and offers insights on possible connections between notions such as relational knowledge, analogy, learning, conceptual knowledge, re-representation and procedural knowledge. This suggests that the approach presented here facilitates mathematical modeling of cognition and provides novel ways to think about analogy-related cognitive phenomena.

  12. New approaches within the history and theory of medicine and their relevance for homeopathy.

    Science.gov (United States)

    Schmidt, Josef M

    2014-04-01

    Conventional sciences have brought forth a wealth of knowledge and benefits, but they have not always been clear and precise about their legitimate scope and methodological limitations. In contrast, new and critical approaches in modern sciences question and reflect their own presuppositions, dependencies, and constraints. Examples are quantum physics, theory and history of science, as well as theory and history of medicine, sociology, and economics. In this way, deprecative dogmatism and animosity amongst sciences ought to be lessened, while the field opens up for each science to redefine its appropriate place in society. This would appear to be a chance for homeopathy, as new approaches, especially within the social and economic sciences, suggest that being a follower of Samuel Hahnemann (1755-1843) may have advantages and privileges that conventional medicine seems to be lacking and whose relevance was overlooked during the rise of economic thinking in the last two centuries. Copyright © 2013 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  13. Towards a category theory approach to analogy: Analyzing re-representation and acquisition of numerical knowledge

    Science.gov (United States)

    2017-01-01

    Category Theory, a branch of mathematics, has shown promise as a modeling framework for higher-level cognition. We introduce an algebraic model for analogy that uses the language of category theory to explore analogy-related cognitive phenomena. To illustrate the potential of this approach, we use this model to explore three objects of study in cognitive literature. First, (a) we use commutative diagrams to analyze an effect of playing particular educational board games on the learning of numbers. Second, (b) we employ a notion called coequalizer as a formal model of re-representation that explains a property of computational models of analogy called “flexibility” whereby non-similar representational elements are considered matches and placed in structural correspondence. Finally, (c) we build a formal learning model which shows that re-representation, language processing and analogy making can explain the acquisition of knowledge of rational numbers. These objects of study provide a picture of acquisition of numerical knowledge that is compatible with empirical evidence and offers insights on possible connections between notions such as relational knowledge, analogy, learning, conceptual knowledge, re-representation and procedural knowledge. This suggests that the approach presented here facilitates mathematical modeling of cognition and provides novel ways to think about analogy-related cognitive phenomena. PMID:28841643

  14. Applying attachment theory to effective practice with hard-to-reach youth: the AMBIT approach.

    Science.gov (United States)

    Bevington, Dickon; Fuggle, Peter; Fonagy, Peter

    2015-01-01

    Adolescent Mentalization-Based Integrative Treatment (AMBIT) is a developing approach to working with "hard-to-reach" youth burdened with multiple co-occurring morbidities. This article reviews the core features of AMBIT, exploring applications of attachment theory to understand what makes young people "hard to reach," and provide routes toward increased security in their attachment to a worker. Using the theory of the pedagogical stance and epistemic ("pertaining to knowledge") trust, we show how it is the therapeutic worker's accurate mentalizing of the adolescent that creates conditions for new learning, including the establishment of alternative (more secure) internal working models of helping relationships. This justifies an individual keyworker model focused on maintaining a mentalizing stance toward the adolescent, but simultaneously emphasizing the critical need for such keyworkers to remain well connected to their wider team, avoiding activation of their own attachment behaviors. We consider the role of AMBIT in developing a shared team culture (shared experiences, shared language, shared meanings), toward creating systemic contexts supportive of such relationships. We describe how team training may enhance the team's ability to serve as a secure base for keyworkers, and describe an innovative approach to treatment manualization, using a wiki format as one way of supporting this process.

  15. [A non-classical approach to medical practices: Michel Foucault and Actor-Network Theory].

    Science.gov (United States)

    Bińczyk, E

    2001-01-01

    The text presents an analysis of medical practices stemming from two sources: Michel Foucault's conception and the research of Annemarie Mol and John Law, representatives of a trend known as Actor-Network Theory. Both approaches reveal significant theoretical kinship: they can be successfully consigned to the framework of non-classical sociology of science. I initially refer to the cited conceptions as a version of non-classical sociology of medicine. The identity of non-classical sociology of medicine hinges on the fact that it undermines the possibility of objective definitions of disease, health and body. These are rather approached as variable social and historical phenomena, co-constituted by medical practices. To both Foucault and Mol the main object of interest was not medicine as such, but rather the network of medical practices. Mol and Law sketch a new theoretical perspective for the analysis of medical practices. They attempt to go beyond the dichotomous scheme of thinking about the human body as an object of medical research and the subject of private experience. Research on patients suffering blood-sugar deficiency provide the empirical background for the thesis of Actor-Network Theory representatives. Michel Foucault's conceptions are extremely critical of medical practices. The French researcher describes the processes of 'medicalising' Western society as the emergence of a new type of power. He attempts to sensitise the reader to the ethical dimension of the processes of medicalising society.

  16. Fragment approach to constrained density functional theory calculations using Daubechies wavelets

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, Laura E., E-mail: lratcliff@anl.gov [Argonne Leadership Computing Facility, Argonne National Laboratory, Lemont, Illinois 60439 (United States); Université de Grenoble Alpes, CEA, INAC-SP2M, L-Sim, F-38000 Grenoble (France); Genovese, Luigi; Mohr, Stephan; Deutsch, Thierry [Université de Grenoble Alpes, CEA, INAC-SP2M, L-Sim, F-38000 Grenoble (France)

    2015-06-21

    In a recent paper, we presented a linear scaling Kohn-Sham density functional theory (DFT) code based on Daubechies wavelets, where a minimal set of localized support functions are optimized in situ and therefore adapted to the chemical properties of the molecular system. Thanks to the systematically controllable accuracy of the underlying basis set, this approach is able to provide an optimal contracted basis for a given system: accuracies for ground state energies and atomic forces are of the same quality as an uncontracted, cubic scaling approach. This basis set offers, by construction, a natural subset where the density matrix of the system can be projected. In this paper, we demonstrate the flexibility of this minimal basis formalism in providing a basis set that can be reused as-is, i.e., without reoptimization, for charge-constrained DFT calculations within a fragment approach. Support functions, represented in the underlying wavelet grid, of the template fragments are roto-translated with high numerical precision to the required positions and used as projectors for the charge weight function. We demonstrate the interest of this approach to express highly precise and efficient calculations for preparing diabatic states and for the computational setup of systems in complex environments.

  17. Deconstructing dementia and delirium hospital practice: using cultural historical activity theory to inform education approaches.

    Science.gov (United States)

    Teodorczuk, Andrew; Mukaetova-Ladinska, Elizabeta; Corbett, Sally; Welfare, Mark

    2015-08-01

    Older patients with dementia and delirium receive suboptimal hospital care. Policy calls for more effective education to address this though there is little consensus on what this entails. The purpose of this clarification study is to explore how practice gaps are constructed in relation to managing the confused hospitalised older patient. The intent is to inform educational processes in the work-place beyond traditional approaches such as training. Adopting grounded theory as a research method and working within a social constructionist paradigm we explored the practice gaps of 15 healthcare professionals by interview and conducted five focus groups with patients, carers and Liaison mental health professionals. Data were thematically analysed by constant comparison and theoretical sampling was undertaken until saturation reached. Categories were identified and pragmatic concepts developed grounded within the data. Findings were then further analysed using cultural historical activity theory as a deductive lens. Practice gaps in relation to managing the confused older patient are determined by factors operating at individual (knowledge and skill gaps, personal philosophy, task based practice), team (leadership, time and ward environmental factors) and organisational (power relationships, dominance of medical model, fragmentation of care services) levels. Conceptually, practice appeared to be influenced by socio-cultural ward factors and compounded by a failure to join up existing "patient" knowledge amongst professionals. Applying cultural historical activity theory to further illuminate the findings, the central object is defined as learning about the patient and the mediating artifacts are the care relationships. The overarching medical dominance emerges as an important cultural historical factor at play and staff rules and divisions of labour are exposed. Lastly key contradictions and tensions in the system that work against learning about the patient are

  18. Aurophilic Interactions from Wave Function, Symmetry-Adapted Perturbation Theory, and Rangehybrid Approaches.

    Science.gov (United States)

    Liu, Ru-Fen; Franzese, Christina A; Malek, Ryan; Żuchowski, Piotr S; Ángyán, János G; Szczȩśniak, Małgorzata M; Chałasiński, Grzegorz

    2011-08-09

    The aurophilic interaction is examined in three model systems Au2((3)Σg(+)), (AuH)2, and (HAuPH3)2 which contain interactions of pairs of the Au centers in the oxidation state (I). Several methods are employed ranging from wave function theory-based (WFT) approaches to symmetry-adapted perturbation theory (SAPT) and range-separated hybrid (RSH) density functional theory (DFT) methods. The most promising and accurate approach consists of a combination of the DFT and WFT approaches in the RSH framework. In this combination the short-range DFT handles the slow convergence of the correlation cusp, whereas the long-range WFT is best suited for the long-range correlation. Of the three tested RSH DFT methods, the one which uses a short-range exchange functional based on the Ernzerhof-Perdew exchange hole model with a range-separation parameter of 0.4 bohr(-1) seems to be the best candidate for treatment of gold. In combination with the long-range coupled cluster singles, doubles, and noniterative triples [CCSD(T)] treatment it places the strength of aurophilic bonding in (HAuPH3)2 at 5.7 kcal/mol at R = 3.09 Å. This value is somewhat larger than our best purely WFT result based on CCSD(T), 4.95 kcal/mol (R = 3.1 Å), and considerably smaller than the Hartree-Fock+dispersion value of 7.4 kcal/mol (R = 2.9 Å). The 5.7 kcal/mol estimate fits reasonably well within the prediction of the empirical relationship proposed by Schwerdtfeger et al. (J. Am. Chem. Soc.1998, 120, 6587). A direct computation of dispersion energy, including exchange corrections, results in values of ca. -9 kcal/mol for Au2((3)Σg(+)) and (AuH)2 and -13 kcal/mol for (HAuPH3)2 at the distance of a typical aurophilic bond, R = 3.0 Å.

  19. Implementing a Teaching Approach Based on the Multiple Intelligence Theory in a South African School: A Case Study

    Science.gov (United States)

    Pienaar, H. C.; Nieman, M. M.; Kamper, G. D.

    2011-01-01

    This article reports on the implementation of a teaching approach based on Gardner's theory of multiple intelligences (MI) at a school in the Hammanskraal area in Gauteng, South Africa. The aim was to determine the impact that such an approach would have on teachers, learners and learner performance. This article discusses the implementation…

  20. Using the Dynamic Model to develop an evidence-based and theory-driven approach to school improvement

    NARCIS (Netherlands)

    Creemers, B.P.M.; Kyriakides, L.

    2010-01-01

    This paper refers to a dynamic perspective of educational effectiveness and improvement stressing the importance of using an evidence-based and theory-driven approach. Specifically, an approach to school improvement based on the dynamic model of educational effectiveness is offered. The recommended

  1. A Review on Block Matching Motion Estimation and Automata Theory based Approaches for Fractal Coding

    Directory of Open Access Journals (Sweden)

    Shailesh Kamble

    2016-12-01

    Full Text Available Fractal compression is the lossy compression technique in the field of gray/color image and video compression. It gives high compression ratio, better image quality with fast decoding time but improvement in encoding time is a challenge. This review paper/article presents the analysis of most significant existing approaches in the field of fractal based gray/color images and video compression, different block matching motion estimation approaches for finding out the motion vectors in a frame based on inter-frame coding and intra-frame coding i.e. individual frame coding and automata theory based coding approaches to represent an image/sequence of images. Though different review papers exist related to fractal coding, this paper is different in many sense. One can develop the new shape pattern for motion estimation and modify the existing block matching motion estimation with automata coding to explore the fractal compression technique with specific focus on reducing the encoding time and achieving better image/video reconstruction quality. This paper is useful for the beginners in the domain of video compression.

  2. Theory versus practice at implementation of inquiry-based approaches into physics education

    Science.gov (United States)

    Pfefferová, Miriam Spodniaková; Raganová, Janka; Hruška, Martin; Holec, Stanislav

    2017-01-01

    At present a lot of ideas for student inquiry-based activities accompanied with methodical remarks and instructions for teachers exist and can be used at physics lessons at lower and upper secondary levels. A need of the use of the teaching methods that support an independent student work as well as active learning approaches has been reflected also in the Slovak state educational program at various educational levels. Experiences of teachers who have used inquiry-based approaches in the classrooms are often in the contrary with expectations of these didactical trends. The paper aims to compare the theory and the practice of the implementation of inquiry-based activities in physics teaching. Practical experience was gained implementing activities for science education developed within the Chain Reaction project running at Matej Bel University Banska Bystrica. Opinions of teachers were investigated with the help of questionnaires, evaluation meetings and structured interviews. Their analysis identified many problems that the teachers had met during the implementation of the inquiry-based approaches in their teaching, as well as benefits of those activities for development of student competences.

  3. Improving concept design of divertor support system for FAST tokamak using TRIZ theory and AHP approach

    Energy Technology Data Exchange (ETDEWEB)

    Di Gironimo, G., E-mail: giuseppe.digironimo@unina.it [Association Euratom/ENEA/CREATE, Università di Napoli Federico II, P.le Tecchio 80, 80125 Napoli (Italy); Carfora, D.; Esposito, G.; Labate, C.; Mozzillo, R.; Renno, F.; Lanzotti, A. [Association Euratom/ENEA/CREATE, Università di Napoli Federico II, P.le Tecchio 80, 80125 Napoli (Italy); Siuko, M. [VTT Systems Engineering, Tekniikankatu 1, 33720 Tampere (Finland)

    2013-11-15

    Highlights: • Optimization of the RH system for the FAST divertor using TRIZ. • Participative design approach using virtual reality. • Comparison of product alternatives in an immersive virtual reality environment. • Prioritization of concept alternatives based on AHP. -- Abstract: The paper focuses on the application of the Theory of Inventive Problem Solving (TRIZ) to divertor Remote Handling (RH) issues in Fusion Advanced Studies Torus (FAST), a satellite tokamak acting as a test bed for the study and the development of innovative technologies oriented to ITER and DEMO programs. The objective of this study consists in generating concepts or solutions able to overcome design and technical weak points in the current maintenance procedure. Two different concepts are designed with the help of a parametric CAD software, CATIA V5, using a top-down modeling approach; kinematic simulations of the remote handling system are performed using Digital Mock-Up (DMU) capabilities of the software. The evaluation of the concepts is carried out involving a group of experts in a participative design approach using virtual reality, classifying the concepts with the help of the Analytical Hierarchy Process (AHP)

  4. Coalitional game theory as a promising approach to identify candidate autism genes.

    Science.gov (United States)

    Gupta, Anika; Sun, Min Woo; Paskov, Kelley Marie; Stockham, Nate Tyler; Jung, Jae-Yoon; Wall, Dennis Paul

    2018-01-01

    Despite mounting evidence for the strong role of genetics in the phenotypic manifestation of Autism Spectrum Disorder (ASD), the specific genes responsible for the variable forms of ASD remain undefined. ASD may be best explained by a combinatorial genetic model with varying epistatic interactions across many small effect mutations. Coalitional or cooperative game theory is a technique that studies the combined effects of groups of players, known as coalitions, seeking to identify players who tend to improve the performance--the relationship to a specific disease phenotype--of any coalition they join. This method has been previously shown to boost biologically informative signal in gene expression data but to-date has not been applied to the search for cooperative mutations among putative ASD genes. We describe our approach to highlight genes relevant to ASD using coalitional game theory on alteration data of 1,965 fully sequenced genomes from 756 multiplex families. Alterations were encoded into binary matrices for ASD (case) and unaffected (control) samples, indicating likely gene-disrupting, inherited mutations in altered genes. To determine individual gene contributions given an ASD phenotype, a "player" metric, referred to as the Shapley value, was calculated for each gene in the case and control cohorts. Sixty seven genes were found to have significantly elevated player scores and likely represent significant contributors to the genetic coordination underlying ASD. Using network and cross-study analysis, we found that these genes are involved in biological pathways known to be affected in the autism cases and that a subset directly interact with several genes known to have strong associations to autism. These findings suggest that coalitional game theory can be applied to large-scale genomic data to identify hidden yet influential players in complex polygenic disorders such as autism.

  5. The mechanistic approach of The Theory of Island Biogeography and its current relevance.

    Science.gov (United States)

    Pâslaru, Viorel

    2014-03-01

    Philosophers of science have examined The Theory of Island Biogeography by Robert MacArthur and E. O. Wilson (1967) mainly due to its important contribution to modeling in ecology, but they have not examined it as a representative case of ecological explanation. In this paper, I scrutinize the type of explanation used in this paradigmatic work of ecology. I describe the philosophy of science of MacArthur and Wilson and show that it is mechanistic. Based on this account and in light of contributions to the mechanistic conception of explanation due to Craver (2007), and Bechtel and Richardson (1993), I argue that MacArthur and Wilson use a mechanistic approach to explain the species-area relationship. In light of this examination, I formulate a normative account of mechanistic explanation in ecology. Furthermore, I argue that it offers a basis for methodological unification of ecology and solves a dispute on the nature of ecology. Lastly, I show that proposals for a new paradigm of biogeography appear to maintain the norms of mechanistic explanation implicit in The Theory of Island Biogeography. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. A Game Theory Approach to Multi-Agent Decentralized Energy Management of Autonomous Polygeneration Microgrids

    Directory of Open Access Journals (Sweden)

    Christos-Spyridon Karavas

    2017-11-01

    Full Text Available Energy management systems are essential and indispensable for the secure and optimal operation of autonomous polygeneration microgrids which include distributed energy technologies and multiple electrical loads. In this paper, a multi-agent decentralized energy management system was designed. In particular, the devices of the microgrid under study were controlled as interactive agents. The energy management problem was formulated here through the application of game theory, in order to model the set of strategies between two players/agents, as a non-cooperative power control game or a cooperative one, according to the level of the energy produced by the renewable energy sources and the energy stored in the battery bank, for the purpose of accomplishing optimal energy management and control of the microgrid operation. The Nash equilibrium was used to compromise the possible diverging goals of the agents by maximizing their preferences. The proposed energy management system was then compared with a multi-agent decentralized energy management system where all the agents were assumed to be cooperative and employed agent coordination through Fuzzy Cognitive Maps. The results obtained from this comparison, demonstrate that the application of game theory based control, in autonomous polygeneration microgrids, can ensure operational and financial benefits over known energy management approaches incorporating distributed intelligence.

  7. Information Theory Approach to Evaluate the Geomagnetic and Ionospheric Response to Solar Wind Parameters

    Science.gov (United States)

    Seemala, G. K.; R, S.; Bhaskara, V.; Ramesh, D. S.

    2014-12-01

    The importance of space weather and understanding onset o geomagnetic storms is increasing day by day as the space missions increase. It is known from the ground-based and space-borne observations that a geomagnetic storm is a temporary disturbance of earth's magnetosphere caused by a solar wind and/or solar eruptions. Geomagnetic storms are more disruptive now than in the past because of our greater dependence on technical systems that can be affected by electric currents and energetic particles high in the Earth's magnetosphere. It is known that number of phenomena occurs during the space weather events; and there are many un-solved questions like solar wind coupling with magnetosphere and ionosphere, relationship between geomagnetic storms & sub-storms etc. To evaluate contribution of various interplanetary parameters that have major role in the geomagnetic storm/geomagnetic variations, the information theory approach is used. In information theory, the measure of uncertainty or randomness of a signal can be quantified by using Shannon entropy or entropy for short. And Transfer entropy is capable of quantifying the directional flow of information between two signals. Thus the Transfer entropy is capable of distinguishing effectively driving and responding signals. In this study, we use Transfer entropy function on Solar wind parameters and ground magnetic data to derive the drivers and relations between them, and also study their contributed effect on ionospheric TEC. In this presentation, we will evaluate and present the results obtained, and discuss about the driving forces on the geomagnetic field disturbances.

  8. A network theory approach for a better understanding of overland flow connectivity

    Science.gov (United States)

    Masselink, Rens; Heckmann, Tobias; Temme, Arnaud; Anders, Niels; Keesstra, Saskia

    2016-04-01

    Hydrological connectivity describes the physical coupling, or linkages of different elements within a landscape regarding (sub)surface flows. A firm understanding of hydrological connectivity is important for catchment management applications, for e.g. habitat and species protection, and for flood resistance and resilience improvement. Thinking about (geomorphological) systems as networks can lead to new insights, which has been recognised within the scientific community as well, seeing the recent increase in the use of network (graph) theory within the geosciences. Network theory supports the analysis and understanding of complex systems by providing data structures for modelling objects and their linkages, and a versatile toolbox to quantitatively appraise network structure and properties. The objective of this study was to characterise overland flow connectivity dynamics on hillslopes in a humid sub-Mediterranean environment by using a combination of high-resolution digital-terrain models, overland flow sensors and a network approach. Results showed that there are significant differences between overland flow on agricultural areas and semi-natural shrubs areas. Positive correlations between connectivity and precipitation characteristics were found, while negative correlations between connectivity and soil moisture were found, probably due to soil water repellency. The combination of a structural network to determine potential connectivity with dynamic networks to determine the actual connectivity proved a powerful tool in analysing overland flow connectivity.

  9. A Hybrid Statistics/Amplitude Approach to the Theory of Interacting Drift Waves and Zonal Flows

    Science.gov (United States)

    Parker, Jeffrey; Krommes, John

    2012-10-01

    An approach to the theory of drift-wave--zonal-flow systems is adopted in which only the DW statistics but the full ZF amplitude are kept. Any statistical description of turbulence must inevitably face the closure problem. A particular closure, the Stochastic Structural Stability Theory (SSST), has been recently studied in plasmafootnotetextB. F. Farrell and P. J. Ioannou, Phys. Plasmas 16, 112903 (2009). as well as atmospheric-science contexts. First, the predictions of the SSST are examined in the weakly inhomogeneous limit, using the generalized Hasegawa--Mima model as a simple example. It is found that the equations do not admit a complete solution, as the characteristic ZF scale cannot be calculated. To address that deficiency, an analysis is performed of a bifurcation from a DW-only state to a DW--ZF state in the Hasegawa--Wakatani model in order to gain analytical insight into a nonlinear DW--ZF equilibrium, including prediction of the charactistic scale. The calculation permits discussion of the relative importance of eddy shearing and coupling to damped eigenmodes for the saturation of the self-consistently regulated turbulence level.

  10. Support Needs for Canadian Health Providers Responding to Disaster: New Insights from a Grounded Theory Approach.

    Science.gov (United States)

    Fahim, Christine; O'Sullivan, Tracey L; Lane, Dan

    2015-07-01

    An earlier descriptive study exploring the various supports available to Canadian health and social service providers who deployed to the 2010 earthquake disaster in Haiti, indicated that when systems are compromised, professionals are at physical, emotional and mental risk during overseas deployment. While these risks are generally well-identified, there is little literature that explores the effectiveness of the supports in place to mitigate this risk. This study provides evidence to inform policy development regarding future disaster relief, and the effectiveness of supports available to responders assisting with international disaster response. This study follows Strauss and Corbin's 1990 structured approach to grounded theory to develop a framework for effective disaster support systems. N=21 interviews with Canadian health and social service providers, who deployed to Haiti in response to the 2010 earthquake, were conducted and analyzed. Resulting data were transcribed, coded and analysed for emergent themes. Three themes were identified in the data and were used to develop the evolving theory. The interview data indicate that the experiences of responders are determined based on an interaction between the individual's 'lens' or personal expectations, as well as the supports that an organization is able to provide. Therefore, organizations should consider the following factors: experience, expectations, and supports, to tailor a successful support initiative that caters to the needs of the volunteer workforce.

  11. Managing Reputational Risk through Environmental Management and Reporting: An Options Theory Approach

    Directory of Open Access Journals (Sweden)

    Juan Pineiro-Chousa

    2017-03-01

    Full Text Available Reputation is a complex and multidimensional concept that may be organized in downside and upside reputational risk. In this article, we present a formal modelling for the management capabilities of environmental management and reporting over reputational risk, considering that reputational risk is becoming increasingly important for organizations and it directly depends on the information available about companies’ environmental performances. As long as the effectiveness of communication and disclosure plays a key role in the process, the usefulness of environmental management and reporting as a hedging instrument for reputational risk is addressed through different levels of information transparency. When considering a scenario of voluntary reporting, we show that environmentally concerned companies can reduce the cost of environmental management as a reputational risk strategy, as well as reducing the potential loss of reputational value from reputational threats and increasing the potential profit from reputational opportunities. In the context of mandatory reporting, we highlight the role of assurance companies as bearers of the risk of bad reputations for non-concerned companies. As a result, this novel approach applies theoretical oriented research from options theory to reputational risk management literature, so that it benefits from the option’s well known theory, robustness, and conclusions.

  12. Effective field theory approach to open heavy flavor production in heavy-ion collisions

    Science.gov (United States)

    Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

    2017-03-01

    We develop a version of Soft Collinear Effective Theory (SCET) which includes finite quark masses, as well as Glauber gluons that describe the interaction of collinear partons with QCD matter. In the framework of this new effective field theory, labeled SCETM,G, we derive the massive splitting functions in the vacuum and the QCD medium for the processes Q → Qg, Q → gQ and g\\to Q\\overline{Q} . The numerical effects due to finite quark masses are sizable and our results are consistent with the traditional approach to parton energy loss in the soft gluon emission limit. In addition, we present a new framework for including the medium-induced full splitting functions consistent with next-to-leading order calculations in QCD for inclusive hadron production. Finally, we show numerical results for the suppression of D- and B-mesons in heavy ion collisions at √{s_{NN}}=5.02 TeV and 2.76 TeV and compare to available data from the LHC.

  13. The limits of lubrication theory for a disk approaching a parallel plane wall

    Science.gov (United States)

    Trahan, Jeffrey F.; Wehbeh, Elias G.; Hussey, R. G.

    1987-04-01

    Measurements have been made of the velocity of a thin circular disk of radius r, as it falls with its axis vertical, through a viscous liquid toward a horizontal plane boundary. The distance from the fixed plane to the bottom surface of the disk is denoted by h. For h3r the results agree with the far-field boundary effect formula derived by Brenner [J. Fluid Mech. 12, 35 (1962)]. An empirical expression is proposed for intermediate values of h. The squeeze film solutions for both a circular cylinder and a sphere approaching a plane are compared with the exact solutions for a cylinder [D. J. Jeffrey and Y. Onishi, Q. J. Mech. Appl. Math. 34, 129 (1981)] and a sphere [H. Brenner, Chem. Eng. Sci. 16, 242 (1961)] and empirical formulas are proposed for the departure from lubrication theory in these two cases.

  14. Behavioural changes in dementia and their impact on professional caregivers: A grounded theory approach.

    Science.gov (United States)

    Appleton, Katie; Pereira, Antonina

    2017-01-01

    Aim The present study aimed to explore the impact that changes in behavioural symptoms of people living with dementia have on professional caregiver and resident relationships. Method A total of 21 interviews were carried out with professional caregivers of people living with dementia. A grounded theory approach was used to investigate everyday experiences of provision of professional care in dementia settings, focussing specifically on the effect of behavioural change on such relationships. Results A core category emerged from this analysis: 'Developing behaviour in dementia impacts relationships on a personal and professional level'. Discussion Professionals have recognized as part of their everyday practice an eventual deterioration in relationships between themselves as professional caregivers and the residents, but also between the residents and their family members and among residents themselves. Importantly, understanding patients' behaviour and behavioural change was identified as a crucial factor to achieve and sustain good relationships between professionals and residents suffering with dementia.

  15. Complementary medicines in medicine: Conceptualising terminology among Australian medical students using a constructivist grounded theory approach.

    Science.gov (United States)

    Templeman, Kate; Robinson, Anske; McKenna, Lisa

    2015-02-01

    Terminology around the use of complementary medicines (CM) within medical discourse is ambiguous. Clear collective discourse within the medical context is required. This study reports the findings of a Constructivist Grounded Theory Method study used to explore medical students' conceptualisation of terminology and associated value components around CMs as evidenced within their discourse community. The results show that terminology surrounding CMs within medicine is politically charged and fraught with value judgements. Terms used to describe CMs were considered, many of which were deemed problematic. Categorisation of specific medicines was also deemed inappropriate in certain contexts. Conceptualisation of CM terminology, categorisation and value implications, discriminated between levels of evidence for CMs and provided insights into the social change of medicine towards emergence of an evidence-based integrative approach. The results show that terminology surrounding CM is a social construct consistent with fluid conceptualisation and operationalisation in different social contexts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A Grey Theory Based Multiple Attribute Approach for R&D Project Portfolio Selection

    Directory of Open Access Journals (Sweden)

    Rupak Bhattacharyya

    2015-06-01

    Full Text Available In this paper, the research and development (R&D project portfolio selection problem is introduced as a multiple attribute decision making problem. Recognizing and modeling the project interdependencies provide valuable cost savings and other greater benefits to organizations. Therefore, besides conventional attributes like cost and outcome, different type of interdependencies are also considered as attributes. Since the decision makers’ preferences on the project alternatives or attributes are uncertain, a grey theory based method is proposed to cope with the uncertainty. correspondingly, the preferences and ratings of the attributes are described by linguistic variables, which are further expressed as grey numbers. Consequently, a ranking order of the projects is done using grey possibility degree and is used to determine the portfolio. To explore, an illustration is done by a case study. The methodology proposed here is shown to be an efficient approach to solve the R&D project portfolio selection problem.

  17. Finite temperature and the Polyakov loop in the covariant variational approach to Yang-Mills Theory

    Science.gov (United States)

    Quandt, Markus; Reinhardt, Hugo

    2017-03-01

    We extend the covariant variational approach for Yang-Mills theory in Landau gauge to non-zero temperatures. Numerical solutions for the thermal propagators are presented and compared to high-precision lattice data. To study the deconfinement phase transition, we adapt the formalism to background gauge and compute the effective action of the Polyakov loop for the colour groups SU(2) and SU(3). Using the zero-temperature propagators as input, all parameters are fixed at T = 0 and we find a clear signal for a deconfinement phase transition at finite temperatures, which is second order for SU(2) and first order for SU(3). The critical temperatures obtained are in reasonable agreement with lattice data.

  18. The Temporal Sensitivity of Enforced Accelerated Work Pace: A grounded theory building approach

    Directory of Open Access Journals (Sweden)

    Graham John James Kenealy, BA (Hons, Ph.D. Candidate

    Full Text Available This research explores how a large national UK government organisation copes with radical structural change over time and provides an insight into the temporal effects of ‘Enforced Accelerated Work Pace’ on behaviour and receptivity within an organisational context. The stages of ‘Acceptance’, ‘Reaction’ and‘Withdrawal’ capture the essence of the ‘Coping Reflex Actions relating to Enforced Accelerated Work Pace’, all sensitive to the effects of time. ‘Temporal Sensitivity’; the duration of the changes to work patterns played a large part in the behavioural responses. The underlying logic of this research is grounded theory building, a general method that works well with qualitative data collection approaches and involves inducting insights from field based, case data (Glaser, 1998. A methodology discovered and developed by Glaser and Strauss (1967, negating all others.

  19. Health effects of digital textbooks on school-age children: a grounded theory approach.

    Science.gov (United States)

    Seomun, Gyeongae; Lee, Jung-Ah; Kim, Eun-Young; Im, Meeyoung; Kim, Miran; Park, Sun-A; Lee, Youngjin

    2013-10-01

    This qualitative study used the grounded theory approach to analyze digital textbook-related health experiences of school-age children. In-depth interviews were held with 40 elementary school students who had used digital textbooks for at least a year. Data analysis revealed a total of 56 concepts, 20 subcategories, and 11 categories related to digital textbook health issues, the central phenomena being "health-related experiences." Students' health-related experiences were classified into "physical" and "psychological" symptoms. Adverse health effects related to digital textbook usage were addressed via both "student-led" and "instructor-led" coping strategies. Students' coping strategies were often inefficient, but instructor-led strategies seemed to prevent health problems. When health issues were well managed, students tended to accept digital textbooks as educational tools. Our findings suggest that students can form healthy computer habits if digital textbook usage is directed in a positive manner.

  20. About renormalization of the Yang - Mills theory and the approach to calculation of the heat kernel

    Science.gov (United States)

    Ivanov, Aleksandr

    2017-10-01

    The quantum theory of Yang - Mills in four-dimensional space - time plays an important role in modern theoretical physics. Currently, this model contains many open problems, therefore, it is of great interest to mathematicians. This work consists of several parts, however, it only offers a new approach and, therefore, it is methodological. First of all, the diagram technique and the mathematical basis will be recalled in the first part. Then the process of renormalization will be explained. It is based on momentum cut-off regularization and described in [1] and [2]. However, this type of the regularization has several problems, as a result, only the first correction is calculated. After common constructions and observations, the first correction will be described in detail. Namely, the heat kernel will be considered since it plays a main role in this formalism. In particular, the method for calculating of coefficients of arbitrary order will be proposed.

  1. Enterprise Factors Contributing to The Success of Malaysian Biotechnology SMEs: A Grounded Theory Approach

    Directory of Open Access Journals (Sweden)

    Saridan Abu Bakar

    2007-10-01

    Full Text Available While numerous empirical studies have been conducted in Western countries on biotechnology enterprises, little empirical research has been done in Malaysia especially in respect to the factors that contribute to the success of biotechnology small and medium enterprises (SMEs. In view of this, a study was undertaken recently in Malaysia to address this gap in the existing body of biotechnology knowledge. Using a grounded theory approach, this qualitative study managed to develop a conceptual framework that sheds useful information on the enterprise factors that significantly impact the success of Malaysian biotechnology SMEs. Specifically, this study found that organizational structure, innovation activities, linkages with academic research institutions, linkages with other private enterprises, personal linkages with academic researchers, access to financial capital, the procuring of government assistances, vertical integration, enterprise image, GMP compliance and halal certification, strongly influence enterprise success.

  2. Ranking Journals Using Social Choice Theory Methods: A Novel Approach in Bibliometrics

    Energy Technology Data Exchange (ETDEWEB)

    Aleskerov, F.T.; Pislyakov, V.; Subochev, A.N.

    2016-07-01

    We use data on economic, management and political science journals to produce quantitative estimates of (in)consistency of evaluations based on seven popular bibliometric indica (impact factor, 5-year impact factor, immediacy index, article influence score, h-index, SNIP and SJR). We propose a new approach to aggregating journal rankings: since rank aggregation is a multicriteria decision problem, ordinal ranking methods from social choice theory may solve it. We apply either a direct ranking method based on majority rule (the Copeland rule, the Markovian method) or a sorting procedure based on a tournament solution, such as the uncovered set and the minimal externally stable set. We demonstrate that aggregate rankings reduce the number of contradictions and represent the set of single-indicator-based rankings better than any of the seven rankings themselves. (Author)

  3. Critical dynamics a field theory approach to equilibrium and non-equilibrium scaling behavior

    CERN Document Server

    Täuber, Uwe C

    2014-01-01

    Introducing a unified framework for describing and understanding complex interacting systems common in physics, chemistry, biology, ecology, and the social sciences, this comprehensive overview of dynamic critical phenomena covers the description of systems at thermal equilibrium, quantum systems, and non-equilibrium systems. Powerful mathematical techniques for dealing with complex dynamic systems are carefully introduced, including field-theoretic tools and the perturbative dynamical renormalization group approach, rapidly building up a mathematical toolbox of relevant skills. Heuristic and qualitative arguments outlining the essential theory behind each type of system are introduced at the start of each chapter, alongside real-world numerical and experimental data, firmly linking new mathematical techniques to their practical applications. Each chapter is supported by carefully tailored problems for solution, and comprehensive suggestions for further reading, making this an excellent introduction to critic...

  4. Truncated Hilbert Space Approach for the 1+1D phi^4 Theory

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    (an informal seminar, not a regular string seminar) We used the massive analogue of the truncated conformal space approach to study the broken phase of the 1+1 dimensional scalar phi^4 model in finite volume, similarly to the work by S. Rychkov and L. Vitale. In our work, the finite size spectrum was determined numerically using an effective eigensolver routine, which was followed by a simple extrapolation in the cutoff energy. We analyzed both the periodic and antiperiodic sectors. The results were compared with semiclassical and Bethe-Yang results as well as perturbation theory. We obtained the coupling dependence of the infinite volume breather and kink masses for moderate couplings. The results fit well with semiclassics and perturbative estimations, and confirm the conjecture of Mussardo that at most two neutral excitations can exist in the spectrum. We believe that improving our method with the renormalization procedure of Rychkov et al. enables to measure further interesting quantities such as decay ra...

  5. An Innovative Approach to Stakeholder Theory: application in spanish transnational corporations

    Directory of Open Access Journals (Sweden)

    Jose Luis Retolaza

    2015-09-01

    Full Text Available Objective – This paper describes a different perspective on the application of stakeholder theory, concentrating only on the interests of stakeholders rather than on their roles. The purpose of this article is to provide an option for solving Jensen’s “problem of governance”; this approach will allow the agent to manage the stakeholders having ascertained that the needs of stakeholders overlap and, accordingly, the agent should be able to monitor multiple stakes as they are aligned. Design/methodology/approach – A Delphi method was used with the aim to achieve consensus about the interests of stakeholders for companies in Spain. The confirmatory phase was based on interviews to test whether the interests identified in the preliminary study match the interests that the IBEX-35 firms recognized in relation with their stakeholders. Findings – The main contributions are: the addition of a new interestbased perspective to the different classifications made by stakeholder theory; a solution to the diversity of indicators between stakeholders and shareholders; and, finally, a proposal for an integrated accounting system, incorporating economic as well as social issues employing a common metric (monetary. Practical implications – A new perspective focusing on stakeholder interests and the confirmation that interests may converge permits the control and management of multiple principals in transnational corporations operating in different countries. Originality/value – There is a gap in the applicability of stakeholder management that the interest-based perspective can help resolve; moreover the monetization of social value is an option to efficiently manage transnational corporations.

  6. Endogenous Molecular-Cellular Network Cancer Theory: A Systems Biology Approach.

    Science.gov (United States)

    Wang, Gaowei; Yuan, Ruoshi; Zhu, Xiaomei; Ao, Ping

    2018-01-01

    In light of ever apparent limitation of the current dominant cancer mutation theory, a quantitative hypothesis for cancer genesis and progression, endogenous molecular-cellular network hypothesis has been proposed from the systems biology perspective, now for more than 10 years. It was intended to include both the genetic and epigenetic causes to understand cancer. Its development enters the stage of meaningful interaction with experimental and clinical data and the limitation of the traditional cancer mutation theory becomes more evident. Under this endogenous network hypothesis, we established a core working network of hepatocellular carcinoma (HCC) according to the hypothesis and quantified the working network by a nonlinear dynamical system. We showed that the two stable states of the working network reproduce the main known features of normal liver and HCC at both the modular and molecular levels. Using endogenous network hypothesis and validated working network, we explored genetic mutation pattern in cancer and potential strategies to cure or relieve HCC from a totally new perspective. Patterns of genetic mutations have been traditionally analyzed by posteriori statistical association approaches in light of traditional cancer mutation theory. One may wonder the possibility of a priori determination of any mutation regularity. Here, we found that based on the endogenous network theory the features of genetic mutations in cancers may be predicted without any prior knowledge of mutation propensities. Normal hepatocyte and cancerous hepatocyte stable states, specified by distinct patterns of expressions or activities of proteins in the network, provide means to directly identify a set of most probable genetic mutations and their effects in HCC. As the key proteins and main interactions in the network are conserved through cell types in an organism, similar mutational features may also be found in other cancers. This analysis yielded straightforward and testable

  7. Patch definition in metapopulation analysis: a graph theory approach to solve the mega-patch problem.

    Science.gov (United States)

    Cavanaugh, Kyle C; Siegel, David A; Raimondi, Peter T; Alberto, Filipe

    2014-02-01

    The manner in which patches are delineated in spatially realistic metapopulation models will influence the size, connectivity, and extinction and recolonization dynamics of those patches. Most commonly used patch-definition methods focus on identifying discrete, contiguous patches of habitat from a single temporal observation of species occurrence or from a model of habitat suitability. However, these approaches are not suitable for many metapopulation systems where entire patches may not be fully colonized at a given time. For these metapopulation systems, a single large patch of habitat may actually support multiple, interacting subpopulations. The interactions among these subpopulations will be ignored if the patch is treated as a single unit, a situation we term the "mega-patch problem." Mega-patches are characterized by variable intra-patch synchrony, artificially low inter-patch connectivity, and low extinction rates. One way to detect this problem is by using time series data to calculate demographic synchrony within mega-patches. We present a framework for identifying subpopulations in mega-patches using a combination of spatial autocorrelation and graph theory analyses. We apply our approach to southern California giant kelp (Macrocystis pyrifera) forests using a new, long-term (27 years), satellite-based data set of giant kelp canopy biomass. We define metapopulation patches using our method as well as several other commonly used patch delineation methodologies and examine the colonization and extinction dynamics of the metapopulation under each approach. We find that the relationships between patch characteristics such as area and connectivity and the demographic processes of colonizations and extinctions vary among the different patch-definition methods. Our spatial-analysis/graph-theoretic framework produces results that match theoretical expectations better than the other methods. This approach can be used to identify subpopulations in metapopulations

  8. Towards a Theory on the Design of Adaptive Transformation: A Systemic Approach

    Science.gov (United States)

    2010-05-21

    theory requires exploring its differences with GST and chaos theory. In the 1960s, Ludwig von Bertalanffy elaborated GST as a new scientific discipline... Bertalanffy , General System Theory (New York: George Braziller, 1993), 37 (eleventh printing, 1968) 12 “Chaos and instability were not the same at...this field, indispensable references are: James Gleick, Chaos; Ludwig von Bertalanffy , General System Theory; Garnett Williams, Chaos Theory Tamed

  9. Molecular acidity: An accurate description with information-theoretic approach in density functional reactivity theory.

    Science.gov (United States)

    Cao, Xiaofang; Rong, Chunying; Zhong, Aiguo; Lu, Tian; Liu, Shubin

    2018-01-15

    Molecular acidity is one of the important physiochemical properties of a molecular system, yet its accurate calculation and prediction are still an unresolved problem in the literature. In this work, we propose to make use of the quantities from the information-theoretic (IT) approach in density functional reactivity theory and provide an accurate description of molecular acidity from a completely new perspective. To illustrate our point, five different categories of acidic series, singly and doubly substituted benzoic acids, singly substituted benzenesulfinic acids, benzeneseleninic acids, phenols, and alkyl carboxylic acids, have been thoroughly examined. We show that using IT quantities such as Shannon entropy, Fisher information, Ghosh-Berkowitz-Parr entropy, information gain, Onicescu information energy, and relative Rényi entropy, one is able to simultaneously predict experimental pKa values of these different categories of compounds. Because of the universality of the quantities employed in this work, which are all density dependent, our approach should be general and be applicable to other systems as well. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Change of Brain Functional Connectivity in Patients With Spinal Cord Injury: Graph Theory Based Approach.

    Science.gov (United States)

    Min, Yu-Sun; Chang, Yongmin; Park, Jang Woo; Lee, Jong-Min; Cha, Jungho; Yang, Jin-Ju; Kim, Chul-Hyun; Hwang, Jong-Moon; Yoo, Ji-Na; Jung, Tae-Du

    2015-06-01

    To investigate the global functional reorganization of the brain following spinal cord injury with graph theory based approach by creating whole brain functional connectivity networks from resting state-functional magnetic resonance imaging (rs-fMRI), characterizing the reorganization of these networks using graph theoretical metrics and to compare these metrics between patients with spinal cord injury (SCI) and age-matched controls. Twenty patients with incomplete cervical SCI (14 males, 6 females; age, 55±14.1 years) and 20 healthy subjects (10 males, 10 females; age, 52.9±13.6 years) participated in this study. To analyze the characteristics of the whole brain network constructed with functional connectivity using rs-fMRI, graph theoretical measures were calculated including clustering coefficient, characteristic path length, global efficiency and small-worldness. Clustering coefficient, global efficiency and small-worldness did not show any difference between controls and SCIs in all density ranges. The normalized characteristic path length to random network was higher in SCI patients than in controls and reached statistical significance at 12%-13% of density (pgraph theoretical approach in brain functional connectivity might be helpful to reveal the information processing after SCI. These findings imply that patients with SCI can build on preserved competent brain control. Further analyses, such as topological rearrangement and hub region identification, will be needed for better understanding of neuroplasticity in patients with SCI.

  11. Polarization effects on spectra of spherical core/shell nanostructures: Perturbation theory against finite difference approach

    Energy Technology Data Exchange (ETDEWEB)

    Ibral, Asmaa [Equipe d' Optique et Electronique du Solide, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida principale, El Jadida, Royaume du Maroc (Morocco); Laboratoire d' Instrumentation, Mesure et Contrôle, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida principale, El Jadida, Royaume du Maroc (Morocco); Zouitine, Asmaa [Département de Physique, Ecole Nationale Supérieure d' Enseignement Technique, Université Mohammed V Souissi, B. P. 6207 Rabat-Instituts, Rabat, Royaume du Maroc (Morocco); Assaid, El Mahdi, E-mail: eassaid@yahoo.fr [Equipe d' Optique et Electronique du Solide, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida principale, El Jadida, Royaume du Maroc (Morocco); Laboratoire d' Instrumentation, Mesure et Contrôle, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida principale, El Jadida, Royaume du Maroc (Morocco); and others

    2015-02-01

    Poisson equation is solved analytically in the case of a point charge placed anywhere in a spherical core/shell nanostructure, immersed in aqueous or organic solution or embedded in semiconducting or insulating matrix. Conduction and valence band-edge alignments between core and shell are described by finite height barriers. Influence of polarization charges induced at the surfaces where two adjacent materials meet is taken into account. Original expressions of electrostatic potential created everywhere in the space by a source point charge are derived. Expressions of self-polarization potential describing the interaction of a point charge with its own image–charge are deduced. Contributions of double dielectric constant mismatch to electron and hole ground state energies as well as nanostructure effective gap are calculated via first order perturbation theory and also by finite difference approach. Dependencies of electron, hole and gap energies against core to shell radii ratio are determined in the case of ZnS/CdSe core/shell nanostructure immersed in water or in toluene. It appears that finite difference approach is more efficient than first order perturbation method and that the effect of polarization charge may in no case be neglected as its contribution can reach a significant proportion of the value of nanostructure gap.

  12. A Grey Theory Based Approach to Big Data Risk Management Using FMEA

    Directory of Open Access Journals (Sweden)

    Maisa Mendonça Silva

    2016-01-01

    Full Text Available Big data is the term used to denote enormous sets of data that differ from other classic databases in four main ways: (huge volume, (high velocity, (much greater variety, and (big value. In general, data are stored in a distributed fashion and on computing nodes as a result of which big data may be more susceptible to attacks by hackers. This paper presents a risk model for big data, which comprises Failure Mode and Effects Analysis (FMEA and Grey Theory, more precisely grey relational analysis. This approach has several advantages: it provides a structured approach in order to incorporate the impact of big data risk factors; it facilitates the assessment of risk by breaking down the overall risk to big data; and finally its efficient evaluation criteria can help enterprises reduce the risks associated with big data. In order to illustrate the applicability of our proposal in practice, a numerical example, with realistic data based on expert knowledge, was developed. The numerical example analyzes four dimensions, that is, managing identification and access, registering the device and application, managing the infrastructure, and data governance, and 20 failure modes concerning the vulnerabilities of big data. The results show that the most important aspect of risk to big data relates to data governance.

  13. An improved theoretical approach to the empirical corrections of density functional theory.

    Science.gov (United States)

    Lii, Jenn-Huei; Hu, Ching-Han

    2012-02-01

    An empirical correction to density functional theory (DFT) has been developed in this study. The approach, called correlation corrected atomization-dispersion (CCAZD), involves short- and long-range terms. Short-range correction consists of bond (1,2-) and angle (1,3-) interactions, which remedies the deficiency of DFT in describing the proto-branching stabilization effects. Long-range correction includes a Buckingham potential function aiming to account for the dispersion interactions. The empirical corrections of DFT were parameterized to reproduce reported ΔH ( f ) values of the training set containing alkane, alcohol and ether molecules. The ΔH ( f ) of the training set molecules predicted by the CCAZD method combined with two different DFT methods, B3LYP and MPWB1K, with a 6-31G* basis set agreed well with the experimental data. For 106 alkane, alcohol and ether compounds, the average absolute deviations (AADs) in ΔH ( f ) were 0.45 and 0.51 kcal/mol for B3LYP- and MPWB1K-CCAZD, respectively. Calculations of isomerization energies, rotational barriers and conformational energies further validated the CCAZD approach. The isomerization energies improved significantly with the CCAZD treatment. The AADs for 22 energies of isomerization reactions were decreased from 3.55 and 2.44 to 0.55 and 0.82 kcal/mol for B3LYP and MPWB1K, respectively. This study also provided predictions of MM4, G3, CBS-QB3 and B2PLYP-D for comparison. The final test of the CCAZD approach on the calculation of the cellobiose analog potential surface also showed promising results. This study demonstrated that DFT calculations with CCAZD empirical corrections achieved very good agreement with reported values for various chemical reactions with a small basis set as 6-31G*.

  14. Predicting critical temperatures of iron(II) spin crossover materials: Density functional theory plus U approach

    Science.gov (United States)

    Zhang, Yachao

    2014-12-01

    A first-principles study of critical temperatures (Tc) of spin crossover (SCO) materials requires accurate description of the strongly correlated 3d electrons as well as much computational effort. This task is still a challenge for the widely used local density or generalized gradient approximations (LDA/GGA) and hybrid functionals. One remedy, termed density functional theory plus U (DFT+U) approach, introduces a Hubbard U term to deal with the localized electrons at marginal computational cost, while treats the delocalized electrons with LDA/GGA. Here, we employ the DFT+U approach to investigate the Tc of a pair of iron(II) SCO molecular crystals (α and β phase), where identical constituent molecules are packed in different ways. We first calculate the adiabatic high spin-low spin energy splitting ΔEHL and molecular vibrational frequencies in both spin states, then obtain the temperature dependent enthalpy and entropy changes (ΔH and ΔS), and finally extract Tc by exploiting the ΔH/T - T and ΔS - T relationships. The results are in agreement with experiment. Analysis of geometries and electronic structures shows that the local ligand field in the α phase is slightly weakened by the H-bondings involving the ligand atoms and the specific crystal packing style. We find that this effect is largely responsible for the difference in Tc of the two phases. This study shows the applicability of the DFT+U approach for predicting Tc of SCO materials, and provides a clear insight into the subtle influence of the crystal packing effects on SCO behavior.

  15. The demonstration of a theory-based approach to the design of localized patient safety interventions.

    Science.gov (United States)

    Taylor, Natalie; Lawton, Rebecca; Slater, Beverley; Foy, Robbie

    2013-10-16

    There is evidence of unsafe care in healthcare systems globally. Interventions to implement recommended practice often have modest and variable effects. Ideally, selecting and adapting interventions according to local contexts should enhance effects. However, the means by which this can happen is seldom systematic, based on theory, or made transparent. This work aimed to demonstrate the applicability, feasibility, and acceptability of a theoretical domains framework implementation (TDFI) approach for co-designing patient safety interventions. We worked with three hospitals to support the implementation of evidence-based guidance to reduce the risk of feeding into misplaced nasogastric feeding tubes. Our stepped process, informed by the TDF and key principles from implementation literature, entailed: involving stakeholders; identifying target behaviors; identifying local factors (barriers and levers) affecting behavior change using a TDF-based questionnaire; working with stakeholders to generate specific local strategies to address key barriers; and supporting stakeholders to implement strategies. Exit interviews and audit data collection were undertaken to assess the feasibility and acceptability of this approach. Following audit and discussion, implementation teams for each Trust identified the process of checking the positioning of nasogastric tubes prior to feeding as the key behavior to target. Questionnaire results indicated differences in key barriers between organizations. Focus groups generated innovative, generalizable, and adaptable strategies for overcoming barriers, such as awareness events, screensavers, equipment modifications, and interactive learning resources. Exit interviews identified themes relating to the benefits, challenges, and sustainability of this approach. Time trend audit data were collected for 301 patients over an 18-month period for one Trust, suggesting clinically significant improved use of pH and documentation of practice

  16. Introducing a model for competitiveness of suppliers in supply chain through game theory approach

    Directory of Open Access Journals (Sweden)

    Hengameh Cighary Deljavan

    2012-10-01

    Full Text Available Cighary Deljavan and Fariba Sadeghi PDF (300 KAbstract: The purpose of the present study is to introduce a model for competitiveness of suppliers in supply chain through game theory approach in one of the automobile companies of Iran. In this study, the game is based on price and non-price factors and this company is going to estimate the real profit obtained from collaboration with each of supply chain members. This happens by considering the governing competitive condition based on game theory before entering a bit for purchase of α piece as spare part among 8 companies supplying this piece as the supply chain members. According to experts in this industry, the quality is the main non-price competitiveness factor after price. In the current research models, the model introduced by Lu and Tsao (2011 [Lu, J.C., Tsao, Y.C., & Charoensiriwath, C. (2011. Competition Under manufacturer Service and retail price. Economic Modeling, 28,1256-1264.] with two manufacturers- one distributer, being appropriate for the research data, has been considered as the basis and implemented for case study and then it has been extended to n-manufacturers-one common retailer. Following price elasticity of demand, potential size of market or maximum product demand, retailer price, production price, wholesale price, demand amount, manufacturer and retailer profit are estimated under three scenario of manufacturer Stackelberg, Retailer Sackelberg and Vertical Nash. Therefore, by comparing them, price balance points and optimum level of services are specified and the better optimum scenario can be determined. Sensitivity analysis is performed for new model and manufacturers are ranked based on manufacture profit, Retailer profit and customer satisfaction. Finally, in this research in addition to introducing-person game model, customer satisfaction, which has been presented in the previous models as a missed circle are analyzed.

  17. The theory of international relations at the dawn of the twentieth-first century: dialogue, dissidence, approaches

    Directory of Open Access Journals (Sweden)

    Mónica Salomón González

    2001-12-01

    Full Text Available The article considers three main trends in current theorizing on international relations. The first is the dialogue that has been going on among neoliberal (or institutionalist and neorealist authors for the last decade over possibilities for international cooperation. The second is the call for dissidence and/or restructuring of the discipline from “reflectivist” approaches: critical theory, postmodernisms, and feminisms. The third is the attempt to achieve a synthesis of the traditional and reflectivist approaches, an attempt made from both the standpoint of a new constructivist theory as well as from a classical point of view of international society.

  18. An information theory approach for evaluating earth radiation budget (ERB) measurements - Nonuniform sampling of reflected shortwave radiation

    Science.gov (United States)

    Barkstrom, Bruce R.; Direskeneli, Haldun; Halyo, Nesim

    1992-01-01

    An information theory approach to examine the temporal nonuniform sampling characteristics of shortwave (SW) flux for earth radiation budget (ERB) measurements is suggested. The information gain is computed by computing the information content before and after the measurements. A stochastic diurnal model for the SW flux is developed, and measurements for different orbital parameters are examined. The methodology is applied to specific NASA Polar platform and Tropical Rainfall Measuring Mission (TRMM) orbital parameters. The information theory approach, coupled with the developed SW diurnal model, is found to be promising for measurements involving nonuniform orbital sampling characteristics.

  19. A psychosocial approach to dentistry for the underserved: incorporating theory into practice.

    Science.gov (United States)

    Flaer, Paul J; Younis, Mustafa Z; Benjamin, Paul L; Al Hajeri, Maha

    2010-01-01

    Dentistry for the underserved is more than an egalitarian social issue--it is a key factor in the health and social progress of our nation. The first signs or manifestations of several diseases such as varicella (i.e., chicken pox and shingles), STDs, and influenza become apparent in the oral cavity. The value of access to quality dentistry is an immeasurable factor in maintaining general medical health of people and fulfilling their psychosocial needs of pain reduction and enhanced cosmetics. In the United States, for the most part, only the middle and upper classes receive non-extraction, restorative, and prosthetic dentistry that is economically within their ability to pay. In addition, uninsured and poverty-level individuals often must face overwhelming long waiting lists, unnecessary referrals, lack of choice, and bureaucratic hurdles when seeking primary dental care. Therefore, it seems pertinent to put forth the question: What are the critical values and beliefs of psychosocial theory that can underscore the practice of dentistry for underserved populations in the United States? The widely employed public health theory, the health belief model (HBM), is applied to evaluate psychosocial factors in dental care for the underserved. The HBM is used to predict and explain behavioral changes in dental health and associated belief patterns. The HBM as applied to dentistry for the underserved predicts self-perceptions of susceptibility and seriousness of dental disease, health status, cues to action, and self-efficacy. Furthermore, patients can make judgments about benefits, costs, and risks of dental treatment. A theoretical approach to dentistry employing the HBM, mediated by values and culture, can provide significant insights into patient thinking, beliefs, and perceptions. These insights can mediate access to and use of primary care dental services by underserved populations. Evidence-based practice (i.e., based on research using the scientific method) has been

  20. A Graph Theory Approach for Geovisualization of Anthropogenic Land Use Change: An application to Lisbon

    Directory of Open Access Journals (Sweden)

    Eric Vaz

    2013-12-01

    Full Text Available Urban sprawl and growth has experienced increased concern in geographic and environmental literature. Preceding the existence of robust frameworks found in regional and urban planning, as well as urban geography and economics, the spatial properties of allocation of urban land use are still far from being completely understood. This is largely due to the underlying complexity of the change found at the spatial level of urban land use, merging social, economic and natural drivers. The spatial patterns formed, and the connectivity established among the different subsets of land-use types, becomes a complex network of interactions over time, helping to shape the structure of the city. The possibility to merge the configuration of land-use with complex networks may be assessed elegantly through graph theory. Nodes and edges can become abstract representations of typologies of space and are represented into a topological space of different land use types which traditionally share common spatial boundaries. Within a regional framework, the links between adjacent and neighboring urban land use types become better understood, by means of a KamadaKawai algorithm. This study uses land use in Lisbon over three years, 1990, 2000 and 2006, to develop a Kamada-Kawai graph interpretation of land-use as a result of neighboring power. The rapid change witnessed in Lisbon since the nineties, as well as the availability of CORINE Land Cover data in these three time stamps, permits a reflection on anthropogenic land-use change in urban and semi-urban areas in Portugal’s capital. This paper responds to (1 the structure and connectivity of urban land use over time, demonstrating that most of the agricultural land is stressed to transform to urban, gaining a central role in future. (2 Offer a systemic approach to land-use transitions generating what we call spatial memory, where land use change is often unpredictable over space, but becomes evident in a graph theory

  1. When Child Development Meets Economic Game Theory: An Interdisciplinary Approach to Investigating Social Development

    Science.gov (United States)

    Gummerum, Michaela; Hanoch, Yaniv; Keller, Monika

    2008-01-01

    Game theory has been one of the most prominent theories in the social sciences, influencing diverse academic disciplines such as anthropology, biology, economics, and political science. In recent years, economists have employed game theory to investigate behaviors relating to fairness, reciprocity, and trust. Surprisingly, this research has not…

  2. On topological approach to local theory of surfaces in Calabi-Yau threefolds

    DEFF Research Database (Denmark)

    Gukov, Sergei; Liu, Chiu-Chu Melissa; Sheshmani, Artan

    2017-01-01

    We study the web of dualities relating various enumerative invariants, notably Gromov-Witten invariants and invariants that arise in topological gauge theory. In particular, we study Donaldson-Thomas gauge theory and its reductions to D=4 and D=2 which are relevant to the local theory of surfaces...

  3. Developing a mental health care plan in a low resource setting: the theory of change approach.

    Science.gov (United States)

    Hailemariam, Maji; Fekadu, Abebaw; Selamu, Medhin; Alem, Atalay; Medhin, Girmay; Giorgis, Tedla Wolde; DeSilva, Mary; Breuer, Erica

    2015-09-28

    Scaling up mental healthcare through integration into primary care remains the main strategy to address the extensive unmet mental health need in low-income countries. For integrated care to achieve its goal, a clear understanding of the organisational processes that can promote and hinder the integration and delivery of mental health care is essential. Theory of Change (ToC), a method employed in the planning, implementation and evaluation of complex community initiatives, is an innovative approach that has the potential to assist in the development of a comprehensive mental health care plan (MHCP), which can inform the delivery of integrated care. We used the ToC approach to develop a MHCP in a rural district in Ethiopia. The work was part of a cross-country study, the Programme for Improving Mental Health Care (PRIME) which focuses on developing evidence on the integration of mental health in to primary care. An iterative ToC development process was undertaken involving multiple workshops with stakeholders from diverse backgrounds that included representatives from the community, faith and traditional healers, community associations, non-governmental organisations, Zonal, Regional and Federal level government offices, higher education institutions, social work and mental health specialists (psychiatrists and psychiatric nurses). The objective of this study is to report the process of implementing the ToC approach in developing mental health care plan. A total of 46 persons participated in four ToC workshops. Four critical path dimensions were identified: community, health facility, administrative and higher level care organisation. The ToC participants were actively engaged in the process and the ToC encouraged strong commitment among participants. Key opportunities and barriers to implementation and how to overcome these were suggested. During the workshops, a map incorporating the key agreed outcomes and outcome indicators was developed and finalized later

  4. Supporting the use of theory in cross-country health services research: a participatory qualitative approach using Normalisation Process Theory as an example.

    Science.gov (United States)

    O'Donnell, Catherine A; Mair, Frances S; Dowrick, Christopher; Brún, Mary O'Reilly-de; Brún, Tomas de; Burns, Nicola; Lionis, Christos; Saridaki, Aristoula; Papadakaki, Maria; Muijsenbergh, Maria van den; Weel-Baumgarten, Evelyn van; Gravenhorst, Katja; Cooper, Lucy; Princz, Christine; Teunissen, Erik; Mareeuw, Francine van den Driessen; Vlahadi, Maria; Spiegel, Wolfgang; MacFarlane, Anne

    2017-08-21

    To describe and reflect on the process of designing and delivering a training programme supporting the use of theory, in this case Normalisation Process Theory (NPT), in a multisite cross-country health services research study. Participatory research approach using qualitative methods. Six European primary care settings involving research teams from Austria, England, Greece, Ireland, The Netherlands and Scotland. RESTORE research team consisting of 8 project applicants, all senior primary care academics, and 10 researchers. Professional backgrounds included general practitioners/family doctors, social/cultural anthropologists, sociologists and health services/primary care researchers. Views of all research team members (n=18) were assessed using qualitative evaluation methods, analysed qualitatively by the trainers after each session. Most of the team had no experience of using NPT and many had not applied theory to prospective, qualitative research projects. Early training proved didactic and overloaded participants with information. Drawing on RESTORE's methodological approach of Participatory Learning and Action, workshops using role play, experiential interactive exercises and light-hearted examples not directly related to the study subject matter were developed. Evaluation showed the study team quickly grew in knowledge and confidence in applying theory to fieldwork.Recommendations applicable to other studies include: accepting that theory application is not a linear process, that time is needed to address researcher concerns with the process, and that experiential, interactive learning is a key device in building conceptual and practical knowledge. An unanticipated benefit was the smooth transition to cross-country qualitative coding of study data. A structured programme of training enhanced and supported the prospective application of a theory, NPT, to our work but raised challenges. These were not unique to NPT but could arise with the application of any

  5. Insight Mechanism of the Selective Lanosterol Synthase Inhibitor: Molecular Modeling, Docking and Density Functional Theory Approaches.

    Science.gov (United States)

    Karunagaran, Subramanian; Kavitha, Rengarajan; Vadivelu, Muthu; Lee, Keun Woo; Meganathan, Chandrasekaran

    2017-11-10

    Lanosterol synthase (Oxidosqualene cyclase) is an enzyme, which plays a central role in cholesterol and sterols biosynthesis. Lanosterol synthase drugs are used to lower the level of cholesterol in the blood and treat wide variety of diseases like atherosclerosis, coronary heart diseases etc. There is a great interest in the identification of drugs that target this enzyme for anticholesteraemic agent using in silico tools. Ligand based pharmacophore model was developed using Discovery Studio 2.5. The best model was used as a tool to retrieve suitable molecule for Lanosterol synthase inhibitor from commercial database and Virtual screening of large commercially available databases to retrieve the best mole of Hypo1 using. Molecular docking was done using three different tools named as GOLD, GLIDE and AUTODOCK 4.0. Density functional theory approach and Density of State spectrum were carried out using Gaussian 09 and GAUSS SUM 3.0. Contribution of these methods in the selection of anticholesteraemic compounds has been discussed. The best pharmacophore model was used to screen the commercial database. Totally 8 compounds were showed with the best orientation, binding mode and binging energy in the docking analyses. The orbital energies such as HOMO, LUMO and DOS spectrum for 8 hit compounds showed the energy gap that results in charge transfer and stability in the active site region. The results showed that our 8 potent leads could serve for further findings. In silico approaches, our 8 hit compounds could serve as the better understanding to design the novel lanosterol synthase inhibitors as anticholesteraemic activity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. SimSup's Loop: A Control Theory Approach to Spacecraft Operator Training

    Science.gov (United States)

    Owens, Brandon Dewain; Crocker, Alan R.

    2015-01-01

    Immersive simulation is a staple of training for many complex system operators, including astronauts and ground operators of spacecraft. However, while much has been written about simulators, simulation facilities, and operator certification programs, the topic of how one develops simulation scenarios to train a spacecraft operator is relatively understated in the literature. In this paper, an approach is presented for using control theory as the basis for developing the immersive simulation scenarios for a spacecraft operator training program. The operator is effectively modeled as a high level controller of lower level hardware and software control loops that affect a select set of system state variables. Simulation scenarios are derived from a STAMP-based hazard analysis of the operator's high and low level control loops. The immersive simulation aspect of the overall training program is characterized by selecting a set of scenarios that expose the operator to the various inadequate control actions that stem from control flaws and inadequate control executions in the different sections of the typical control loop. Results from the application of this approach to the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission are provided through an analysis of the simulation scenarios used for operator training and the actual anomalies that occurred during the mission. The simulation scenarios and inflight anomalies are mapped to specific control flaws and inadequate control executions in the different sections of the typical control loop to illustrate the characteristics of anomalies arising from the different sections of the typical control loop (and why it is important for operators to have exposure to these characteristics). Additionally, similarities between the simulation scenarios and inflight anomalies are highlighted to make the case that the simulation scenarios prepared the operators for the mission.

  7. Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach

    Directory of Open Access Journals (Sweden)

    Ferruccio ePanzica

    2013-11-01

    Full Text Available In the context of focal drug-resistant epilepsies, the surgical resection of the epileptogenic zone (EZ, the cortical region responsible for the onset, early seizures organization and propagation, may be the only therapeutic option for reducing or suppressing seizures. The rather high rate of failure in epilepsy surgery of extra-temporal epilepsies highlights that the precise identification of the EZ, mandatory objective to achieve seizure freedom, is still an unsolved problem that requires more sophisticated methods of investigation.Despite the wide range of non-invasive investigations, intracranial stereo-EEG (SEEG recordings still represent, in many patients, the gold standard for the EZ identification. In this contest, the EZ localization is still based on visual analysis of SEEG, inevitably affected by the drawback of subjectivity and strongly time-consuming. Over the last years, considerable efforts have been made to develop advanced signal analysis techniques able to improve the identification of the EZ. Particular attention has been paid to those methods aimed at quantifying and characterising the interactions and causal relationships between neuronal populations, since is nowadays well assumed that epileptic phenomena are associated with abnormal changes in brain synchronisation mechanisms, and initial evidence has shown the suitability of this approach for the EZ localisation. The aim of this review is to provide an overview of the different EEG signal processing methods applied to study connectivity between distinct brain cortical regions, namely in focal epilepsies. In addition, with the aim of localizing the EZ, the approach based on graph theory will be described, since the study of the topological properties of the networks has strongly improved the study of brain connectivity mechanisms.

  8. Identification of the Epileptogenic Zone from Stereo-EEG Signals: A Connectivity-Graph Theory Approach.

    Science.gov (United States)

    Panzica, Ferruccio; Varotto, Giulia; Rotondi, Fabio; Spreafico, Roberto; Franceschetti, Silvana

    2013-11-06

    In the context of focal drug-resistant epilepsies, the surgical resection of the epileptogenic zone (EZ), the cortical region responsible for the onset, early seizures organization, and propagation, may be the only therapeutic option for reducing or suppressing seizures. The rather high rate of failure in epilepsy surgery of extra-temporal epilepsies highlights that the precise identification of the EZ, mandatory objective to achieve seizure freedom, is still an unsolved problem that requires more sophisticated methods of investigation. Despite the wide range of non-invasive investigations, intracranial stereo-EEG (SEEG) recordings still represent, in many patients, the gold standard for the EZ identification. In this contest, the EZ localization is still based on visual analysis of SEEG, inevitably affected by the drawback of subjectivity and strongly time-consuming. Over the last years, considerable efforts have been made to develop advanced signal analysis techniques able to improve the identification of the EZ. Particular attention has been paid to those methods aimed at quantifying and characterizing the interactions and causal relationships between neuronal populations, since is nowadays well assumed that epileptic phenomena are associated with abnormal changes in brain synchronization mechanisms, and initial evidence has shown the suitability of this approach for the EZ localization. The aim of this review is to provide an overview of the different EEG signal processing methods applied to study connectivity between distinct brain cortical regions, namely in focal epilepsies. In addition, with the aim of localizing the EZ, the approach based on graph theory will be described, since the study of the topological properties of the networks has strongly improved the study of brain connectivity mechanisms.

  9. Game-Theory-Based Approach for Energy Routing in a Smart Grid Network

    Directory of Open Access Journals (Sweden)

    June S. Hong

    2016-01-01

    Full Text Available Small power plants and buildings with renewable power generation capability have recently been added to traditional central power plants. Through these facilities, prosumers appear to have a concurrent role in both energy production and consumption. Based on bidirectional power transfers by large numbers of prosumers, a smart microgrid has become an important factor in efficiently controlling the microgrids used in power markets and in conducting effective power trades among grids. In this paper, we present an approach utilizing the game theory for effective and efficient energy routing, which is a novel and challenging procedure for a smart microgrid network. First, we propose strategies for choosing the desired transaction price for both electricity surpluses and shortages to maximize profits through energy transactions. An optimization scheme is utilized to search for an energy route with minimum cost using the solving method used in a traditional transportation problem by treating the sale and purchase quantities as transportation supply and demand, respectively. To evaluate the effect of the proposed decision strategies, we simulated our mechanism, and the results proved that our mechanism yields results pursued by each strategy. Our proposed strategies will contribute to spreading a smart microgrid for enhancing the utilization of microgrids.

  10. The problem-solving approach in the teaching of number theory

    Science.gov (United States)

    Toh, Pee Choon; Hoong Leong, Yew; Toh, Tin Lam; Dindyal, Jaguthsing; Quek, Khiok Seng; Guan Tay, Eng; Him Ho, Foo

    2014-02-01

    Mathematical problem solving is the mainstay of the mathematics curriculum for Singapore schools. In the preparation of prospective mathematics teachers, the authors, who are mathematics teacher educators, deem it important that pre-service mathematics teachers experience non-routine problem solving and acquire an attitude that predisposes them to adopt a Pólya-style approach in learning mathematics. The Practical Worksheet is an instructional scaffold we adopted to help our pre-service mathematics teachers develop problem-solving dispositions alongside the learning of the subject matter. The Worksheet was initially used in a design experiment aimed at teaching problem solving in a secondary school. In this paper, we describe an application and adaptation of the MProSE (Mathematical Problem Solving for Everyone) design experiment to a university level number theory course for pre-service mathematics teachers. The goal of the enterprise was to help the pre-service mathematics teachers develop problem-solving dispositions alongside the learning of the subject matter. Our analysis of the pre-service mathematics teachers' work shows that the MProSE design holds promise for mathematics courses at the tertiary level.

  11. How Iranian Medical Trainees Approach their Responsibilities in Clinical Settings; A Grounded Theory Research.

    Science.gov (United States)

    Asemani, Omid; Iman, Mohammad Taghi; Moattari, Marzieh; Khayyer, Mohammad; Sharif, Farkhondeh; Tabei, Seyed Ziaaddin

    2015-09-01

    It seems we are now experiencing "responsibility problems" among medical trainees (MTs) and some of those recently graduated from medical schools in Iran. Training responsible professionals have always been one of the main concerns of medical educators. Nevertheless, there is a dearth of research in the literature on "responsibility" especially from the medical education point of view. Therefore, the present study was carried out with the aim of presenting a theoretical based framework for understanding how MTs approach their responsibilities in educational settings. This qualitative study was conducted at Shiraz University of Medical Sciences (SUMS) using the grounded theory methodology. 15 MTs and 10 clinical experts and professional nurses were purposefully chosen as participants. Data was analyzed using the methodology suggested by Corbin and Strauss, 1998. "Try to find acceptance toward expectations", "try to be committed to meet the expectations" and "try to cope with unacceptable expectations" were three main categories extracted based on the research data. Abstractly, the main objective for using these processes was "to preserve the integrity of student identity" which was the core category of this research too. Moreover, it was also found that practically, "responsibility" is considerably influenced by lots of positive and negative contextual and intervening conditions. "Acceptance" was the most decisive variable highly effective in MTs' responsibility. Therefore, investigating the "process of acceptance" regarding the involved contextual and intervening conditions might help medical educators correctly identify and effectively control negative factors and reinforce the constructive ones that affect the concept of responsibility in MTs.

  12. On the validity of the effective field theory approach to SM precision tests

    Energy Technology Data Exchange (ETDEWEB)

    Contino, Roberto [EPFL, Lausanne (Switzerland). Inst. de Theorie des Phenomenes Physiques; CERN, Geneva (Switzerland). Theoretical Physics Dept.; Falkowski, Adam [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Goertz, Florian; Riva, Francesco [CERN, Geneva (Switzerland). Theoretical Physics Dept.; Grojean, Christophe [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-09-15

    We discuss the conditions for an effective field theory (EFT) to give an adequate low-energy description of an underlying physics beyond the Standard Model (SM). Starting from the EFT where the SM is extended by dimension-6 operators, experimental data can be used without further assumptions to measure (or set limits on) the EFT parameters. The interpretation of these results requires instead a set of broad assumptions (e.g. power counting rules) on the UV dynamics. This allows one to establish, in a bottom-up approach, the validity range of the EFT description, and to assess the error associated with the truncation of the EFT series. We give a practical prescription on how experimental results could be reported, so that they admit a maximally broad range of theoretical interpretations. Namely, the experimental constraints on dimension-6 operators should be reported as functions of the kinematic variables that set the relevant energy scale of the studied process. This is especially important for hadron collider experiments where collisions probe a wide range of energy scales.

  13. Wetting of heterogeneous substrates. A classical density-functional-theory approach

    Science.gov (United States)

    Yatsyshin, Peter; Parry, Andrew O.; Rascón, Carlos; Duran-Olivencia, Miguel A.; Kalliadasis, Serafim

    2017-11-01

    Wetting is a nucleation of a third phase (liquid) on the interface between two different phases (solid and gas). In many experimentally accessible cases of wetting, the interplay between the substrate structure, and the fluid-fluid and fluid-substrate intermolecular interactions leads to the appearance of a whole ``zoo'' of exciting interface phase transitions, associated with the formation of nano-droplets/bubbles, and thin films. Practical applications of wetting at small scales are numerous and include the design of lab-on-a-chip devices and superhydrophobic surfaces. In this talk, we will use a fully microscopic approach to explore the phase space of a planar wall, decorated with patches of different hydrophobicity, and demonstrate the highly non-trivial behaviour of the liquid-gas interface near the substrate. We will present fluid density profiles, adsorption isotherms and wetting phase diagrams. Our analysis is based on a formulation of statistical mechanics, commonly known as classical density-functional theory. It provides a computationally-friendly and rigorous framework, suitable for probing small-scale physics of classical fluids and other soft-matter systems. EPSRC Grants No. EP/L027186,EP/K503733;ERC Advanced Grant No. 247031.

  14. An alternative approach to analyze Ipsative data. Revisiting Experiential Learning Theory

    Directory of Open Access Journals (Sweden)

    Joan Manuel eBatista-Foguet

    2015-11-01

    Full Text Available The ritualistic use of statistical models regardless of the type of data actually available is a common practice across disciplines. Statistical models involve a series of assumptions whose existence is often neglected altogether, thus making the mentioned common practice even more pervasive. This paper illustrates the consequences of this ritualistic practice within Kolb’s Experiential Learning Theory (ELT operationalized through its Learning Style Inventory (KLSI. We show how using a well-known methodology in other disciplines -compositional data analysis (CODA- KLSI data can be properly analyzed. In addition, a third dimension of the KLSI is unveiled providing room for future research. This third dimension describes an individual’s relative preference for learning by prehension rather than by transformation. Using a sample of European MBA students, we relate this dimension with another self-assessment instrument, the Philosophical Orientation Questionnaire (POQ, and with an observer-assessed instrument, the Emotional and Social Inventory (ESCI-U. Both show plausible statistical relationships. An intellectual operating philosophy is linked to a preference for prehension, whereas a pragmatic operating philosophy is linked to transformation. Self-management and social awareness competencies are linked to a learning preference for transforming knowledge, whereas relationship management and cognitive competencies are more related to approaching learning by prehension.

  15. Understanding adolescent type 1 diabetes self-management as an adaptive process: A grounded theory approach.

    Science.gov (United States)

    Chilton, Roy; Pires-Yfantouda, Renata

    2015-01-01

    To develop a conceptual understanding of the process of adapting to the self-management of type 1 diabetes during adolescence. Participants were recruited from a National Health Service paediatric diabetes service within the south-west of England which runs six countywide diabetes clinics. Thirteen interviews were conducted using a social constructivist grounded theory approach. The findings illustrate how self-management can be understood in terms of a continuum-based framework, ranging from difficulties with, to successful self-management. Adaptation within the continuum can further be understood by specific transitional phases and process mechanisms, providing further depth to individuals' experiences of adaptation. This investigation provides a conceptual understanding of the complex issues adolescents encounter while adapting to and integrating a diabetes self-management regime into their lives. It provides an invaluable framework for exploring psychological mechanisms and contextualising them within a self-management continuum. Implications for healthcare professionals are discussed and further research proposes whether the model could be applicable to other chronic illnesses.

  16. Combinatorial theory of the semiclassical evaluation of transport moments. I. Equivalence with the random matrix approach

    Energy Technology Data Exchange (ETDEWEB)

    Berkolaiko, G., E-mail: berko@math.tamu.edu [Department of Mathematics, Texas A and M University, College Station, Texas 77843-3368 (United States); Kuipers, J., E-mail: Jack.Kuipers@physik.uni-regensburg.de [Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg (Germany)

    2013-11-15

    To study electronic transport through chaotic quantum dots, there are two main theoretical approaches. One involves substituting the quantum system with a random scattering matrix and performing appropriate ensemble averaging. The other treats the transport in the semiclassical approximation and studies correlations among sets of classical trajectories. There are established evaluation procedures within the semiclassical evaluation that, for several linear and nonlinear transport moments to which they were applied, have always resulted in the agreement with random matrix predictions. We prove that this agreement is universal: any semiclassical evaluation within the accepted procedures is equivalent to the evaluation within random matrix theory. The equivalence is shown by developing a combinatorial interpretation of the trajectory sets as ribbon graphs (maps) with certain properties and exhibiting systematic cancellations among their contributions. Remaining trajectory sets can be identified with primitive (palindromic) factorisations whose number gives the coefficients in the corresponding expansion of the moments of random matrices. The equivalence is proved for systems with and without time reversal symmetry.

  17. Combinatorial theory of the semiclassical evaluation of transport moments. I. Equivalence with the random matrix approach

    Science.gov (United States)

    Berkolaiko, G.; Kuipers, J.

    2013-11-01

    To study electronic transport through chaotic quantum dots, there are two main theoretical approaches. One involves substituting the quantum system with a random scattering matrix and performing appropriate ensemble averaging. The other treats the transport in the semiclassical approximation and studies correlations among sets of classical trajectories. There are established evaluation procedures within the semiclassical evaluation that, for several linear and nonlinear transport moments to which they were applied, have always resulted in the agreement with random matrix predictions. We prove that this agreement is universal: any semiclassical evaluation within the accepted procedures is equivalent to the evaluation within random matrix theory. The equivalence is shown by developing a combinatorial interpretation of the trajectory sets as ribbon graphs (maps) with certain properties and exhibiting systematic cancellations among their contributions. Remaining trajectory sets can be identified with primitive (palindromic) factorisations whose number gives the coefficients in the corresponding expansion of the moments of random matrices. The equivalence is proved for systems with and without time reversal symmetry.

  18. Global financial indices and twitter sentiment: A random matrix theory approach

    Science.gov (United States)

    García, A.

    2016-11-01

    We use Random Matrix Theory (RMT) approach to analyze the correlation matrix structure of a collection of public tweets and the corresponding return time series associated to 20 global financial indices along 7 trading months of 2014. In order to quantify the collection of tweets, we constructed daily polarity time series from public tweets via sentiment analysis. The results from RMT analysis support the fact of the existence of true correlations between financial indices, polarities, and the mixture of them. Moreover, we found a good agreement between the temporal behavior of the extreme eigenvalues of both empirical data, and similar results were found when computing the inverse participation ratio, which provides an evidence about the emergence of common factors in global financial information whether we use the return or polarity data as a source. In addition, we found a very strong presumption that polarity Granger causes returns of an Indonesian index for a long range of lag trading days, whereas for Israel, South Korea, Australia, and Japan, the predictive information of returns is also presented but with less presumption. Our results suggest that incorporating polarity as a financial indicator may open up new insights to understand the collective and even individual behavior of global financial indices.

  19. Renormalization group theory outperforms other approaches in statistical comparison between upscaling techniques for porous media

    Science.gov (United States)

    Hanasoge, Shravan; Agarwal, Umang; Tandon, Kunj; Koelman, J. M. Vianney A.

    2017-09-01

    Determining the pressure differential required to achieve a desired flow rate in a porous medium requires solving Darcy's law, a Laplace-like equation, with a spatially varying tensor permeability. In various scenarios, the permeability coefficient is sampled at high spatial resolution, which makes solving Darcy's equation numerically prohibitively expensive. As a consequence, much effort has gone into creating upscaled or low-resolution effective models of the coefficient while ensuring that the estimated flow rate is well reproduced, bringing to the fore the classic tradeoff between computational cost and numerical accuracy. Here we perform a statistical study to characterize the relative success of upscaling methods on a large sample of permeability coefficients that are above the percolation threshold. We introduce a technique based on mode-elimination renormalization group theory (MG) to build coarse-scale permeability coefficients. Comparing the results with coefficients upscaled using other methods, we find that MG is consistently more accurate, particularly due to its ability to address the tensorial nature of the coefficients. MG places a low computational demand, in the manner in which we have implemented it, and accurate flow-rate estimates are obtained when using MG-upscaled permeabilities that approach or are beyond the percolation threshold.

  20. How Do the Nurses Cope with Job Stress? A Study with Grounded Theory Approach.

    Science.gov (United States)

    Eslami Akbar, Rasool; Elahi, Nasrin; Mohammadi, Eesa; Fallahi Khoshknab, Masoud

    2017-09-01

    Introduction: Due to the adverse effects of job stress on health of nurses and the importance of coping process of nurses in management of job stress, the present study was carried out with the aim of exploring the experiences of the nurses in order to reveal the original coping process of the nurses in the case of encountering occupational stress. Methods: This qualitative study was conducted with grounded theory approach. Research participants were 15 clinical nurses and four directors of nursing. Sampling method of study were purposive and theoretical sampling. Data collection done with unstructured interviews and field notes and continued until data saturation. Data analysis was performed using the Strauss and Corbin 1998 constant comparative method. Results: The results of the analysis led to four axial concepts: "feeling stress at nursing work", "situational coping", "and the effect of personal and environmental factors in coping with job stress" and "Grey outcome of coping". The core variable in the nurse's process of coping with job stress was "comprehensive effort to calm stressed condition". Conclusion: Explaining the basic and original psychosocial process of nurses to cope with job stress, revealed context-based nature of the coping processes that nurses adopt, which that can help in taking appropriate measures to lighten up the grey consequences of coping of nurses.

  1. How Do the Nurses Cope with Job Stress? A Study with Grounded Theory Approach

    Directory of Open Access Journals (Sweden)

    Rasool Eslami Akbar

    2017-09-01

    Full Text Available Introduction: Due to the adverse effects of job stress on health of nurses and the importance of coping process of nurses in management of job stress, the present study was carried out with the aim of exploring the experiences of the nurses in order to reveal the original coping process of the nurses in the case of encountering occupational stress. Methods: This qualitative study was conducted with grounded theory approach. Research participants were 15 clinical nurses and four directors of nursing. Sampling method of study were purposive and theoretical sampling. Data collection done with unstructured interviews and field notes and continued until data saturation. Data analysis was performed using the Strauss and Corbin 1998 constant comparative method. Results: The results of the analysis led to four axial concepts: "feeling stress at nursing work", "situational coping", "and the effect of personal and environmental factors in coping with job stress" and "Grey outcome of coping". The core variable in the nurse’s process of coping with job stress was "comprehensive effort to calm stressed condition". Conclusion: Explaining the basic and original psychosocial process of nurses to cope with job stress, revealed context-based nature of the coping processes that nurses adopt, which that can help in taking appropriate measures to lighten up the grey consequences of coping of nurses.

  2. A suggested model for decision-making regarding hearing conservation: towards a systems theory approach.

    Science.gov (United States)

    Widén, Stephen Ernst

    2013-01-01

    The aim of the study was to investigate potential health promotion variables associated with adolescents' hearing protection use at concerts. The sample consisted of 242 upper secondary school students aged 15-19 years. Variables defined by the theory of planned behaviour (TBP) and health belief model were tested in this quantitative study. Fifty-three percent of the adolescents reported that they used hearing protection at concerts to some degree, and 33 individuals (14%) reported that they used hearing protection in 50% of cases or more. The average degree of hearing protection use was reported to be 17% of the visits at concerts. Norms, perceived control, barriers, and noise sensitivity were associated with attitudes towards loud music. In addition, norms, barriers, permanent tinnitus, and noise sensitivity were significantly correlated with hearing protection use. However, intention was not significantly correlated with hearing protection use. From a systems theoretical approach it can be suggested that preventive strategies must consider more levels than just the individual, in order to achieve long lasting behavioural changes in adolescents' listening habits. To be able to get useful knowledge about preventive strategies, it is necessary to add context-specific variables into generic models such as TPB.

  3. An Alternative Approach to Analyze Ipsative Data. Revisiting Experiential Learning Theory.

    Science.gov (United States)

    Batista-Foguet, Joan M; Ferrer-Rosell, Berta; Serlavós, Ricard; Coenders, Germà; Boyatzis, Richard E

    2015-01-01

    The ritualistic use of statistical models regardless of the type of data actually available is a common practice across disciplines which we dare to call type zero error. Statistical models involve a series of assumptions whose existence is often neglected altogether, this is specially the case with ipsative data. This paper illustrates the consequences of this ritualistic practice within Kolb's Experiential Learning Theory (ELT) operationalized through its Learning Style Inventory (KLSI). We show how using a well-known methodology in other disciplines-compositional data analysis (CODA) and log ratio transformations-KLSI data can be properly analyzed. In addition, the method has theoretical implications: a third dimension of the KLSI is unveiled providing room for future research. This third dimension describes an individual's relative preference for learning by prehension rather than by transformation. Using a sample of international MBA students, we relate this dimension with another self-assessment instrument, the Philosophical Orientation Questionnaire (POQ), and with an observer-assessed instrument, the Emotional and Social Competency Inventory (ESCI-U). Both show plausible statistical relationships. An intellectual operating philosophy (IOP) is linked to a preference for prehension, whereas a pragmatic operating philosophy (POP) is linked to transformation. Self-management and social awareness competencies are linked to a learning preference for transforming knowledge, whereas relationship management and cognitive competencies are more related to approaching learning by prehension.

  4. MEANINGFUL VARIABILITY: A SOCIOLINGUISTICALLY-GROUNDED APPROACH TO VARIATION IN OPTIMALITY THEORY

    Directory of Open Access Journals (Sweden)

    Juan Antonio Cutillas Espinosa

    2004-12-01

    Full Text Available Most approaches to variability in Optimality Theory have attempted to make variation possible within the OT framework, i.e. to reformulate constraints and rankings to accommodate variable and gradient linguistic facts. Sociolinguists have attempted to apply these theoretical advances to the study of language variation, with an emphasis on language-interna1 variables (Auger 2001, Cardoso 2001. Little attention has been paid to the array of externa1 factors that influence the patterning of variation. In this paper, we argue that some variation pattems-specially those that are socially meaningful- are actually the result of a three-grarnmar system. G, is the standard grammar, which has to be available to the speaker to obtain these variation patterns. G; is the vernacular grammar, which the speaker is likely to have acquired in his local community. Finally, G, is an intergrammar, which is used by the speaker as his 'default' constraint set. G is a continuous ranking (Boersma & Hayes 2001 and domination relations are consciously altered by the speakers to shape the appropriate and variable linguistic output. We illustrate this model with analyses of English and Spanish.

  5. The relativistic statistical theory and Kaniadakis entropy: an approach through a molecular chaos hypothesis

    Science.gov (United States)

    Silva, R.

    2006-12-01

    We have investigated the proof of the H theorem within a manifestly covariant approach by considering the relativistic statistical theory developed in [G. Kaniadakis, Phys. Rev. E 66, 056125 (2002); G. Kaniadakis, Phys. Rev. E 72, 036108 (2005)]. As it happens in the nonrelativistic limit, the molecular chaos hypothesis is slightly extended within the Kaniadakis formalism. It is shown that the collisional equilibrium states (null entropy source term) are described by a κ power law generalization of the exponential Juttner distribution, e.g., f(x,p)∝ (sqrt{1+ kappa^2θ^2}+kappaθ)^{1/kappa}equivexp_kappaθ, with θ=α(x)+βμpμ, where α(x) is a scalar, βμ is a four-vector, and pμ is the four-momentum. As a simple example, we calculate the relativistic κ power law for a dilute charged gas under the action of an electromagnetic field Fμν. All standard results are readly recovered in the particular limit κ→0.

  6. Blood Donation and Citizenship Education. An approach from service learning and the Theory of Don

    Directory of Open Access Journals (Sweden)

    Josep M. PUIG ROVIRA

    2014-12-01

    Full Text Available The altruistic donation of blood recommended by the World Health Organisation and carried out through blood banks not only contributes to providing the health system with an indispensable therapeutic element, it is also a means of fostering social integration and educating for citizenship. Within this general context, the article begins by arguing why altruistic donation is better than buying and selling blood and why the gift theory – developed by sociology on the basis of the work by Marcel Mauss – more than justifies the possibility of meeting the demand for blood in this way. On the basis of these considerations it can be said that blood banks are social institutions that perform three basic functions: technical, civic and educational. The article continues by examining the educational project undertaken by the Blood and Tissue Bank of Catalonia, which consists in a programme based on the methodology of service learning and which invites young people to cultivate and develop a communicative approach to promoting the altruistic donation of blood in their neighbourhood. The article concludes by evaluating the consolidation, effectiveness and degree of satisfaction of the project, and suggesting that this model can be used to form the basis of ideas for educational proposals of other social institutions.

  7. A direct relativistic approach to ligand field theory calculations of spin-orbit components of diatomic molecules

    Science.gov (United States)

    Bencheikh, M.; Schamps, J.

    1997-11-01

    The basic equations of a direct relativistic approach to ligand field theory are derived for the calculation of spin-orbit splittings of diatomic molecules. The decisive advantage of this direct method over the standard perturbational procedure, especially in case of strong spin-orbit effect, are pointed out and discussed.

  8. A Causal Modelling Approach to the Development of Theory-Based Behaviour Change Programmes for Trial Evaluation

    Science.gov (United States)

    Hardeman, Wendy; Sutton, Stephen; Griffin, Simon; Johnston, Marie; White, Anthony; Wareham, Nicholas J.; Kinmonth, Ann Louise

    2005-01-01

    Theory-based intervention programmes to support health-related behaviour change aim to increase health impact and improve understanding of mechanisms of behaviour change. However, the science of intervention development remains at an early stage. We present a causal modelling approach to developing complex interventions for evaluation in…

  9. Strengthening the link between theory and practice in teaching design engineering : An empirical study on a new approach

    NARCIS (Netherlands)

    Tempelman, E.; Pilot, A.

    2010-01-01

    In 2007, the Faculty of Industrial Design Engineering of the Delft University of Technology introduced a new bachelor program. Based on theories of learning and instruction three design principles were used to develop an approach that aims to make it easier for students to bridge the gap between

  10. Theoretical Antecedents of Standing at Work: An Experience Sampling Approach Using the Theory of Planned Behavior

    Directory of Open Access Journals (Sweden)

    M. Renée Umstattd Meyer

    2016-09-01

    Full Text Available Time spent sitting has been associated with an increased risk of diabetes, cancer, obesity, and mental health impairments. However, 75% of Americans spend most of their days sitting, with work-sitting accounting for 63% of total daily sitting time. Little research examining theory-based antecedents of standing or sitting has been conducted. This lack of solid groundwork makes it difficult to design effective intervention strategies to decrease sitting behaviors. Using the Theory of Planned Behavior (TPB as our theoretical lens to better understand factors related with beneficial standing behaviors already being practiced, we examined relationships between TPB constructs and time spent standing at work among “positive deviants” (those successful in behavior change. Experience sampling methodology (ESM, 4 times a day (midmorning, before lunch, afternoon, and before leaving work for 5 consecutive workdays (Monday to Friday, was used to assess employees’ standing time. TPB scales assessing attitude (α = 0.81–0.84, norms (α = 0.83, perceived behavioral control (α = 0.77, and intention (α = 0.78 were developed using recommended methods and collected once on the Friday before the ESM surveys started. ESM data are hierarchically nested, therefore we tested our hypotheses using multilevel structural equation modeling with Mplus. Hourly full-time university employees (n = 50; 70.6% female, 84.3% white, mean age = 44 (SD = 11, 88.2%in full-time staff positions with sedentary occupation types (time at desk while working ≥6 hours/day participated. A total of 871 daily surveys were completed. Only perceived behavioral control (β = 0.45, p < 0.05 was related with work-standing at the event-level (model fit: just fit; mediation through intention was not supported. This is the first study to examine theoretical antecedents of real-time work-standing in a naturalistic field setting among positive deviants. These relationships should be further

  11. Developing a Dual-Level Capabilities Approach: Using Constructivist Grounded Theory and Feminist Ethnography to Enhance the Capabilities Approaches

    Science.gov (United States)

    Hall, Kia M. Q.

    2014-01-01

    In this study, a dual-level capabilities approach to development is introduced. This approach intends to improve upon individual-focused capabilities approaches developed by Amartya Sen and Martha Nussbaum. Based upon seven months of ethnographic research in the Afro-descendant, autochthonous Garifuna community of Honduras, constructivist grounded…

  12. An alternative approach to evaluating, measuring, and comparing domestic and international health institutions: insights from social science theories.

    Science.gov (United States)

    Gómez, Eduardo J

    2011-08-01

    This article introduces the benefits of applying social science theories discussing institutional stasis and change to better measure, explain, and compare elite behavior within health administration and decentralization processes. A new comparative method based on these theories is introduced, as well as methods for collecting and analyzing data. A literature review of health governance, health system governance, and path dependency and institutional change theory was conducted to reveal the limitations of health governance approaches explaining elite behavior. Next, path dependency and institutional change theory was applied to case studies in order to demonstrate their utility in explaining institutional stasis and change. Current approaches to analyzing and comparing elite behavior in the health governance frameworks are limited in their ability to accurately explain the willingness of elites to pursue more efficient institutional and policy designs. Current indicators measuring elite behavior are also too static, failing to account for periodic resistance to change and the conditions for it. By applying path dependency and institutional change theory, the policy community can obtain greater insight into the willingness and thus capacity of institutions to pursue innovations while developing alternative analytic frameworks and databases that better measure and predict this process. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  13. The application of item response theory in developing and validating a shortened version of the Emirate Marital Satisfaction Scale.

    Science.gov (United States)

    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).

  14. Designing Leadership models in a Three Level Unlimited Supply Chain: Non-Cooperative Game Theory Approach

    Directory of Open Access Journals (Sweden)

    Ahmad Jaafarnehad

    2015-09-01

    Full Text Available The role and importance of supply chain management, has faced with many challenges and problems. Although a comprehensive model of supply chain issues, has not been explained, we have to indicate that issues such as reviewing the theoretical foundations of information systems, marketing, financial management, logistical and organizational relations have been considered by many researchers. The objective of supply chain management is to improve various activities and components to increase overall supply chain system benefits. In order to achieve the overall objectives, many contradictions may occur between the components and different levels of supply chain and the contradictions that these disorders over time, result in decreased strength and competitiveness of the supply chain. Such conflicts, like marketing costs (advertising, pricing and inventory can occur during the supply chain life cycle. A Game Theory approach with respect to property is the appropriate tool for collaboration in the supply chain. This tool is used for collaborative making in any kind of supply chain such as cooperative supply chain and non-cooperative supply chain. In the present study and assuming a lack of cooperation between different levels of a supply chain, a dynamic game with complete information has been generated. In addition identifying appropriate leaders of various levels of the supply chain is considered. Non-Cooperative dynamic game mode (Stackelberg Game, for each of the three levels of supply chain including retailers, suppliers and manufacturers are modeled. Depending on the bargaining power and its position in the market, any level of supply chain can make a leader of the following rule. In the present study, the equilibrium model to play Stackelberg game may be led by a leader or leading players and ultimately identifying and modeling the appropriate unlimited three level supply chain are determined.

  15. How Iranian Medical Trainees Approach their Responsibilities in Clinical Settings; A Grounded Theory Research

    Directory of Open Access Journals (Sweden)

    Omid Asemani

    2015-09-01

    Full Text Available Background: It seems we are now experiencing “responsibility problems” among medical trainees (MTs and some of those recently graduated from medical schools in Iran. Training responsible professionals have always been one of the main concerns of medical educators. Nevertheless, there is a dearth of research in the literature on “responsibility” especially from the medical education point of view. Therefore, the present study was carried out with the aim of presenting a theoretical based framework for understanding how MTs approach their responsibilities in educational settings. Method: This qualitative study was conducted at Shiraz University of Medical Sciences (SUMS using the grounded theory methodology. 15 MTs and 10 clinical experts and professional nurses were purposefully chosen as participants. Data was analyzed using the methodology suggested by Corbin and Strauss, 1998. Results: “Try to find acceptance toward expectations”, “try to be committed to meet the expectations” and “try to cope with unacceptable expectations” were three main categories extracted based on the research data. Abstractly, the main objective for using these processes was “to preserve the integrity of student identity” which was the core category of this research too. Moreover, it was also found that practically, “responsibility” is considerably influenced by lots of positive and negative contextual and intervening conditions. Conclusion: “Acceptance” was the most decisive variable highly effective in MTs’ responsibility. Therefore, investigating the “process of acceptance” regarding the involved contextual and intervening conditions might help medical educators correctly identify and effectively control negative factors and reinforce the constructive ones that affect the concept of responsibility in MTs.

  16. John Holland's Contributions: A Theory-Ridden Approach to Career Assistance

    Science.gov (United States)

    Gottfredson, Gary D.; Johnstun, Marissa L.

    2009-01-01

    Holland influenced practice and research in career development by contributing a clear theory useful in organizing information about individuals and career alternatives and for understanding individuals' entry and persistence in occupational and other environments. His theory was repeatedly revised in response to evidence. As Holland's own career…

  17. An anthology of theories and models of design philosophy, approaches and empirical explorations

    CERN Document Server

    Blessing, Lucienne

    2014-01-01

    While investigations into both theories and models has remained a major strand of engineering design research, current literature sorely lacks a reference book that provides a comprehensive and up-to-date anthology of theories and models, and their philosophical and empirical underpinnings; An Anthology of Theories and Models of Design fills this gap. The text collects the expert views of an international authorship, covering: ·         significant theories in engineering design, including CK theory, domain theory, and the theory of technical systems; ·         current models of design, from a function behavior structure model to an integrated model; ·         important empirical research findings from studies into design; and ·         philosophical underpinnings of design itself. For educators and researchers in engineering design, An Anthology of Theories and Models of Design gives access to in-depth coverage of theoretical and empirical developments in this area; for pr...

  18. Robert R. Wilson Prize II: A Quantum Field Theory Approach to Intrabeam Scattering

    Science.gov (United States)

    Bjorken, James

    2017-01-01

    My involvement in the intrabeam scattering problem was very brief, from the autumn of 1981 to the summer of 1982. It occurred during my tenure at Fermilab. I entered the subject as an amateur in accelerator theory. But my experience in elementary-particle theory turned out to be of help in advancing the subject.

  19. A Cultural Historical Activity Theory Approach in Natural Sciences Education Laboratory Lessons towards Reforming Teachers Training

    Science.gov (United States)

    Kolokouri, Eleni; Theodoraki, Xarikleia; Plakitsi, Katerina

    2012-01-01

    This paper focuses on connecting natural sciences education with Cultural Historical Activity Theory (CHAT). In this sense, natural sciences education is considered as a lifelong learning procedure, not seen as an individual but as a collective activity. Moreover, learning becomes a human activity in which theory and praxis are strongly connected…

  20. Information Literacy and Community College Students: Using New Approaches to Literacy Theory to Produce Equity

    Science.gov (United States)

    Patterson, David

    2009-01-01

    Librarians in community colleges have engaged in information literacy (IL) for decades, but their theorizing of IL has never taken equity as a starting point. This article asserts that IL theory radiating from equity requires the animating dynamics that conceptual advances in literacy theory offer. By examining early moments in librarianship to…

  1. Relativistic Many-Body Theory A New Field-Theoretical Approach

    CERN Document Server

    Lindgren, Ingvar

    2011-01-01

    Relativistic Many-Body Theory treats — for the first time — the combination of relativistic atomic many-body theory with quantum-electrodynamics (QED) in a unified manner. This book can be regarded as a continuation of the book by Lindgren and Morrison, Atomic Many-Body Theory (Springer 1986), which deals with the non-relativistic theory of many-electron systems, describing several means of treating the electron correlation to essentially all orders of perturbation theory. The treatment of the present book is based upon quantum-field theory, and demonstrates that when the procedure is carried to all orders of perturbation theory, two-particle systems are fully compatible with the relativistically covariant Bethe-Salpeter equation. This procedure can be applied to arbitrary open-shell systems, in analogy with the standard many-body theory, and it is also applicable to systems with more than two particles. Presently existing theoretical procedures for treating atomic systems are, in several cases, insuffici...

  2. An Integrative Approach: Relational Cultural Theory and Cognitive Behavior Therapy in College Counseling

    Science.gov (United States)

    Crumb, Loni; Haskins, Natoya

    2017-01-01

    This article presents an integrative framework for using cognitive behavior therapy through the lens of relational cultural theory. The authors provide an overview of cognitive behavior therapy and relational cultural theory, followed by suggestions on how to facilitate cognitive behavior therapy using the principles of relational cultural theory…

  3. The method of the generalised eikonal new approaches in the diffraction theory

    CERN Document Server

    Vesnik, Michael V

    2015-01-01

    The diffraction theory describes scattering mechanism for waves of various physical nature, scattered on objects of different shapes and composed of different materials. Using the diffraction theory, one can study a number of important effects connected with wave propagation, and create objects with given properties.

  4. An integrative mechanistic account of psychological distress, therapeutic change and recovery: the Perceptual Control Theory approach.

    Science.gov (United States)

    Higginson, Sally; Mansell, Warren; Wood, Alex M

    2011-03-01

    The exact nature and mechanisms of psychological change within psychological disorders remain unknown. This review aims to use a psychological framework known as Perceptual Control Theory (Powers, 1973, 2005; Powers, Clark, & McFarland, 1960) to integrate the diverse literature within psychotherapy research. The core principles of Perceptual Control Theory are explained, and key domains of psychotherapy are considered to explore how well they converge with these principles. The quantitative and qualitative empirical literature on the process of psychological change is reviewed to examine how it fits with predictions based on Perceptual Control Theory. Furthermore, the prerequisites for psychological change; client qualities, therapist qualities, the therapeutic alliance and the shifting of awareness, are also considered to examine their consistency within a Perceptual Control Theory account. Finally the strengths and limitations of a Perceptual Control Theory account in explaining the mechanism of psychological change are considered. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Harmonization of Neuroticism and Extraversion phenotypes across inventories and cohorts in the Genetics of Personality Consortium: an application of Item Response Theory.

    Science.gov (United States)

    van den Berg, Stéphanie M; de Moor, Marleen H M; McGue, Matt; Pettersson, Erik; Terracciano, Antonio; Verweij, Karin J H; Amin, Najaf; Derringer, Jaime; Esko, Tõnu; van Grootheest, Gerard; Hansell, Narelle K; Huffman, Jennifer; Konte, Bettina; Lahti, Jari; Luciano, Michelle; Matteson, Lindsay K; Viktorin, Alexander; Wouda, Jasper; Agrawal, Arpana; Allik, Jüri; Bierut, Laura; Broms, Ulla; Campbell, Harry; Smith, George Davey; Eriksson, Johan G; Ferrucci, Luigi; Franke, Barbera; Fox, Jean-Paul; de Geus, Eco J C; Giegling, Ina; Gow, Alan J; Grucza, Richard; Hartmann, Annette M; Heath, Andrew C; Heikkilä, Kauko; Iacono, William G; Janzing, Joost; Jokela, Markus; Kiemeney, Lambertus; Lehtimäki, Terho; Madden, Pamela A F; Magnusson, Patrik K E; Northstone, Kate; Nutile, Teresa; Ouwens, Klaasjan G; Palotie, Aarno; Pattie, Alison; Pesonen, Anu-Katriina; Polasek, Ozren; Pulkkinen, Lea; Pulkki-Råback, Laura; Raitakari, Olli T; Realo, Anu; Rose, Richard J; Ruggiero, Daniela; Seppälä, Ilkka; Slutske, Wendy S; Smyth, David C; Sorice, Rossella; Starr, John M; Sutin, Angelina R; Tanaka, Toshiko; Verhagen, Josine; Vermeulen, Sita; Vuoksimaa, Eero; Widen, Elisabeth; Willemsen, Gonneke; Wright, Margaret J; Zgaga, Lina; Rujescu, Dan; Metspalu, Andres; Wilson, James F; Ciullo, Marina; Hayward, Caroline; Rudan, Igor; Deary, Ian J; Räikkönen, Katri; Arias Vasquez, Alejandro; Costa, Paul T; Keltikangas-Järvinen, Liisa; van Duijn, Cornelia M; Penninx, Brenda W J H; Krueger, Robert F; Evans, David M; Kaprio, Jaakko; Pedersen, Nancy L; Martin, Nicholas G; Boomsma, Dorret I

    2014-07-01

    Mega- or meta-analytic studies (e.g. genome-wide association studies) are increasingly used in behavior genetics. An issue in such studies is that phenotypes are often measured by different instruments across study cohorts, requiring harmonization of measures so that more powerful fixed effect meta-analyses can be employed. Within the Genetics of Personality Consortium, we demonstrate for two clinically relevant personality traits, Neuroticism and Extraversion, how Item-Response Theory (IRT) can be applied to map item data from different inventories to the same underlying constructs. Personality item data were analyzed in >160,000 individuals from 23 cohorts across Europe, USA and Australia in which Neuroticism and Extraversion were assessed by nine different personality inventories. Results showed that harmonization was very successful for most personality inventories and moderately successful for some. Neuroticism and Extraversion inventories were largely measurement invariant across cohorts, in particular when comparing cohorts from countries where the same language is spoken. The IRT-based scores for Neuroticism and Extraversion were heritable (48 and 49 %, respectively, based on a meta-analysis of six twin cohorts, total N = 29,496 and 29,501 twin pairs, respectively) with a significant part of the heritability due to non-additive genetic factors. For Extraversion, these genetic factors qualitatively differ across sexes. We showed that our IRT method can lead to a large increase in sample size and therefore statistical power. The IRT approach may be applied to any mega- or meta-analytic study in which item-based behavioral measures need to be harmonized.

  6. Dynamical density functional theory for molecular and colloidal fluids: a microscopic approach to fluid mechanics.

    Science.gov (United States)

    Archer, A J

    2009-01-07

    In recent years, a number of dynamical density functional theories (DDFTs) have been developed for describing the dynamics of the one-body density of both colloidal and atomic fluids. In the colloidal case, the particles are assumed to have stochastic equations of motion and theories exist for both the case when the particle motion is overdamped and also in the regime where inertial effects are relevant. In this paper, we extend the theory and explore the connections between the microscopic DDFT and the equations of motion from continuum fluid mechanics. In particular, starting from the Kramers equation, which governs the dynamics of the phase space probability distribution function for the system, we show that one may obtain an approximate DDFT that is a generalization of the Euler equation. This DDFT is capable of describing the dynamics of the fluid density profile down to the scale of the individual particles. As with previous DDFTs, the dynamical equations require as input the Helmholtz free energy functional from equilibrium density functional theory (DFT). For an equilibrium system, the theory predicts the same fluid one-body density profile as one would obtain from DFT. Making further approximations, we show that the theory may be used to obtain the mode coupling theory that is widely used for describing the transition from a liquid to a glassy state.

  7. The birth of the universe in a new G-Theory approach

    CERN Document Server

    Sepehri, Alireza

    2016-01-01

    Recently, Padmanabhan has discussed that the expansion of the cosmic space is due to the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region. Now, a natural question arises that how these degrees of freedom are emerged from nothing? We try to address this issue in a new theory which is more complete than M-theory and reduces to it with some limitations. In M-theory, there isn't any stable object like stable M3-branes that our universe be formed on it and for this reason can't help us to explain cosmological events. In this research, we have proposed a new model named G (God)-theory which could be the mother of M-theory and superstring theory. In G-theory, at the beginning, two types of G0-branes, one with positive energy and one with negative energy are produced from nothing in fourteen dimensions. Then, these branes are compactified on three circles via two different ways (symmetrically and anti-symmetrically), and two bosonic and ...

  8. The person centered approach, gerontological attention and national policy of humanization: approaches among theory, praxis and public policy

    OpenAIRE

    Caires, Cristiano Santos; Faculdade de Medicina do ABC - FMABC; Araujo, Eliana Novaes P.; Pontifícia Universidade Católica de São Paulo

    2014-01-01

    The purpose of this study is to improve understanding of care focused on elderly population growing, based on singularity values and attitude that privilege an active and participatory aging at public network services. Thus, the possibilities of fit among Rogerian theory, as a care guide focused on elderly attention, and the SUS humanization primer aim the Brazilian gerontological care improvement. New meanings and thoughts that overlap, in terms of those professionals attitudes that, based o...

  9. The birth of the universe in a new G-theory approach

    Science.gov (United States)

    Sepehri, Alireza; Pincak, Richard

    2017-02-01

    Recently, Padmanabhan has discussed that the expansion of the cosmic space is due to the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region. Now, a natural question arises that how these degrees of freedom emerged from nothing? We try to address this issue in a new theory which is more complete than M-theory and reduces to it with some limitations. In M-theory, there is no stable object like stable M3-branes that our universe is formed on it and for this reason cannot help us to explain cosmological events. In this research, we propose a new theory, named G-theory which could be the mother of M-theory and superstring theory. In G-theory, at the beginning, two types of G0-branes, one with positive energy and one with negative energy are produced from nothing in 14 dimensions. Then, these branes are compactified on three circles via two different ways (symmetrically and anti-symmetrically), and two bosonic and fermionic parts of action for M0-branes are produced. By joining M0-branes, supersymmetric Mp-branes are created which contain the equal number of degrees of freedom for fermions and bosons. Our universe is constructed on one of Mp-branes and other Mp-brane and extra energy play the role of bulk. By dissolving extra energy which is produced by compacting actions of Gp-branes, into our universe, the number of degrees of freedom on it and also its scale factor increase and universe expands. We test G-theory with observations and find that the magnitude of the slow-roll parameters and the tensor-to-scalar ratio in this model are very much smaller than one which are in agreement with predictions of experimental data. Finally, we consider the origin of the extended theories of gravity in G-theory and show that these theories could be anomaly free.

  10. General approach for solving the density gradient theory in the interfacial tension calculations

    DEFF Research Database (Denmark)

    Liang, Xiaodong; Michelsen, Michael Locht

    2017-01-01

    Within the framework of the density gradient theory, the interfacial tension can be calculated by finding the density profiles that minimize an integral of two terms over the system of infinite width. It is found that the two integrands exhibit a constant difference along the interface for a finite...... property evaluations compared to other methods. The performance of the algorithm with recommended parameters is analyzed for various systems, and the efficiency is further compared with the geometric-mean density gradient theory, which only needs to solve nonlinear algebraic equations. The results show...... that the algorithm is only 5-10 times less efficient than solving the geometric-mean density gradient theory....

  11. Universality and the approach to the continuum limit in lattice gauge theory

    CERN Document Server

    De Divitiis, G M; Guagnelli, M; Lüscher, Martin; Petronzio, Roberto; Sommer, Rainer; Weisz, P; Wolff, U; de Divitiis, G; Frezzotti, R; Guagnelli, M; Luescher, M; Petronzio, R; Sommer, R; Weisz, P; Wolff, U

    1995-01-01

    The universality of the continuum limit and the applicability of renormalized perturbation theory are tested in the SU(2) lattice gauge theory by computing two different non-perturbatively defined running couplings over a large range of energies. The lattice data (which were generated on the powerful APE computers at Rome II and DESY) are extrapolated to the continuum limit by simulating sequences of lattices with decreasing spacings. Our results confirm the expected universality at all energies to a precision of a few percent. We find, however, that perturbation theory must be used with care when matching different renormalized couplings at high energies.

  12. Universality and the approach to the continuum limit in lattice gauge theory

    Science.gov (United States)

    de Divitiis, Giulia; Frezzotti, Roberto; Guagnelli, Marco; Lüscher, Martin; Petronzio, Roberto; Sommer, Rainer; Weisz, Peter; Wolff, Ulli

    1995-02-01

    The universality of the continuum limit and the applicability of renormalized perturbation theory are tested in the SU(2) lattice gauge theory by computing two different non-perturbatively defined running couplings over a large range of energies. The lattice data (which were generated on the powerful APE computers at Rome II and DESY) are extrapolated to the continuum limit by simulating sequences of lattices with decreasing spacings. Our results confirm the expected universality at all energies to a precision of a few percent. We find, however, that perturbation theory must be used with care when matching different renormalized couplings at high energies.

  13. Damage Based Analysis (DBA) - Theory, Derivation and Practical Application Using Both an Acceleration and Pseudo Velocity Approach

    Science.gov (United States)

    Grillo, Vince

    2017-01-01

    The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a maximax approach.

  14. Damage Based Analysis (DBA): Theory, Derivation and Practical Application - Using Both an Acceleration and Pseudo-Velocity Approach

    Science.gov (United States)

    Grillo, Vince

    2016-01-01

    The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a Maximax approach.

  15. A Formal Approach to User Interface Design using Hybrid System Theory Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Optimal Synthesis Inc.(OSI) proposes to develop an aiding tool for user interface design that is based on mathematical formalism of hybrid system theory. The...

  16. Management Research and Grounded Theory: A review of grounded theorybuilding approach in organisational and management research.

    Directory of Open Access Journals (Sweden)

    Graham J.J. Kenealy, Ph.D.

    2008-06-01

    Full Text Available Grounded theory is a systematic methodology for the collection and analysis of data which was discovered by Glaser and Strauss in the 1960’s. The discovery of this method was first presented to the academic community in their book ‘The Discovery of Grounded Theory’ (1967 which still remains a primary point of reference for those undertaking qualitative research and grounded theory in particular. This powerful research method has become very popular in some research domains; whilst increasing in popularity it is still less prevalent in the field of organisational and management research particularly in its original form. This self reflexive paper sets out to explore the possibilities for this imbalance which takes the discussion onto the areas of methodological adaptation and training. It also enters the debate about access to research subjects and provides a succinct argument supporting the notion that grounded theory should simply be viewed as a method that develops empirically grounded conceptual theory.

  17. Fuzzy Saturated Output Feedback Tracking Control for Robot Manipulators: A Singular Perturbation Theory Based Approach

    National Research Council Canada - National Science Library

    Liu, Huashan; Hao, Kuangrong; Lai, Xiaobo

    2011-01-01

    To deal with the problem of the output feedback tracking (OFT) control with bounded torque inputs of robot manipulators, we propose a generalized fuzzy saturated OFT controller based on singular perturbation theory...

  18. Critical theory as an approach to the ethics of information security.

    Science.gov (United States)

    Stahl, Bernd Carsten; Doherty, Neil F; Shaw, Mark; Janicke, Helge

    2014-09-01

    Information security can be of high moral value. It can equally be used for immoral purposes and have undesirable consequences. In this paper we suggest that critical theory can facilitate a better understanding of possible ethical issues and can provide support when finding ways of addressing them. The paper argues that critical theory has intrinsic links to ethics and that it is possible to identify concepts frequently used in critical theory to pinpoint ethical concerns. Using the example of UK electronic medical records the paper demonstrates that a critical lens can highlight issues that traditional ethical theories tend to overlook. These are often linked to collective issues such as social and organisational structures, which philosophical ethics with its typical focus on the individual does not tend to emphasise. The paper suggests that this insight can help in developing ways of researching and innovating responsibly in the area of information security.

  19. The image of cell in biology books: an approach from Cognitive Theory of Multimedia Learning

    National Research Council Canada - National Science Library

    Ricardo Ferreira das Neves; Ana Maria dos Anjos Carneiro-Leão; Helaine Sivini Ferreira

    2016-01-01

    The research aimed to analyze the didactic value (VD) of the images related to the concept of cell in biology books of High School and Higher Education, supported by Cognitivist Theory of Multimedia Learning (TCAM...

  20. Theory-Driven Process Evaluation of the SHINE Trial Using a Program Impact Pathway Approach

    National Research Council Canada - National Science Library

    Mbuya, Mduduzi N N; Jones, Andrew D; Ntozini, Robert; Humphrey, Jean H; Moulton, Lawrence H; Stoltzfus, Rebecca J; Maluccio, John A

    2015-01-01

    Two reasons for the lack of success of programs or interventions are poor alignment of interventions with the causes of the problem targeted by the intervention, leading to poor efficacy (theory failure...

  1. Language Management Theory as One Approach in Language Policy and Planning

    Science.gov (United States)

    Nekvapil, Jirí

    2016-01-01

    Language Policy and Planning is currently a significantly diversified research area and thus it is not easy to find common denominators that help to define basic approaches within it. Richard B. Baldauf attempted to do so by differentiating between four basic approaches: (1) the classical approach, (2) the language management approach (Language…

  2. PRODUCTION OF DERMEVAL SAVIANI: FIRST APPROACHES TO TREATING THE ARTICLES EDUCATIONAL THEORY

    Directory of Open Access Journals (Sweden)

    Carolina Nozella Gama

    2015-06-01

    Full Text Available Result of doctoral studies that have been conducted by the PPGE/Ufba, this article presents a survey about the academic production of Dermeval Saviani. Recovers briefly the history of the author, emphasizing how his experience as a teacher provided him real problems to think and make propositions about educational theory. Then, we present a brief description of its production, highlighting the articles that deal with pedagogical theory, and the core themes treated in the same.

  3. Risk Perception and Communication in Vaccination Decisions: A Fuzzy-Trace Theory Approach

    OpenAIRE

    REYNA, VALERIE F.

    2011-01-01

    The tenets of fuzzy-trace theory, along with prior research on risk perception and risk communication, are used to develop a process model of vaccination decisions in the era of Web 2.0. The theory characterizes these decisions in terms of background knowledge, dual mental representations (verbatim and gist), retrieval of values, and application of values to representations in context. Lack of knowledge interferes with the ability to extract the essential meaning, or gist, of vaccination mess...

  4. The Solutions of Argyris Maturation Theory by The Situational Approaches to Leadership

    OpenAIRE

    ÖZTÜRK, Cemal

    2016-01-01

    Chris Argyris criticized the points of work sharing, power and responsibility, The principle of unity of command, control area in classical management Theory. According to him, these issues are adversely affects employees, cause not to find themselves, not to improve themselves and shortly to inability to mature. In this case, deeply search of these reasons should be done to adjust this negative situation to success of administration. First of all, Chris Argyris and the Theory of Maturity/imm...

  5. The transition of childbirth practices among tribal women in Gujarat, India - a grounded theory approach

    Science.gov (United States)

    2013-01-01

    Background Under the National Rural Health Mission, the current emphasis is on achieving universal institutional births through incentive schemes as part of reforms related to childbirth in India. There has been rapid progress in achieving this goal. To understand the choices made as well as practices and perceptions related to childbirth amongst tribal women in Gujarat and how these have been influenced by modernity in general and modernity brought in through maternal health policies. Method A model depicting the transition in childbirth practices amongst tribal women was constructed using the grounded theory approach with; 8 focus groups of women, 5 in depth interviews with traditional birth attendants, women, and service providers and field notes on informal discussions and observations. Results A transition in childbirth practices across generations was noted, i.e. a shift from home births attended by Traditional Birth Attendants (TBAs) to hospital births. The women and their families both adapted to and shaped this transition through a constant ’trade-off between desirable and essential’- the desirable being a traditional homebirth in secure surroundings and the essential being the survival of mother and baby by going to hospital. This transition was shaped by complex multiple factors: 1) Overall economic growth and access to modern medical care influencing women’s choices, 2) External context in terms of the international maternal health discourses and national policies, especially incentive schemes for promoting institutional deliveries, 3) Socialisation into medical childbirth practices, through exposure to many years of free outreach services for maternal and child health, 4) Loss of self reliance in the community as a consequence of role redefinition and deskilling of the TBAs and 5) Cultural belief that intervention is necessary during childbirth aiding easy acceptance of medical interventions. Conclusion In resource poor settings where choices are

  6. A Theory-Based Approach for Developing Interventions to Change Patient Behaviours: A Medication Adherence Example from Paediatric Secondary Care

    Directory of Open Access Journals (Sweden)

    Gemma Heath

    2015-12-01

    Full Text Available In this article we introduce a Health Psychology approach to changing patient behaviour, in order to demonstrate the value of Health Psychology professional practice as applied within healthcare settings. Health Psychologists are experts in understanding, predicting and changing health-related behaviours at the individual, group and population level. They combine psychological theory, research evidence and service-user views to design interventions to solve clinically relevant behavioural problems and improve health outcomes. We provide a pragmatic overview of a theory and evidence-based Intervention Mapping approach for developing, implementing and evaluating interventions to change health-related behaviour. An example of a real behaviour change intervention designed to improve medication adherence in an adolescent patient with poorly controlled asthma is described to illustrate the main stages of the intervention development process.

  7. The interpretive approach and bridging the 'theory-practice gap' : action research with student teachers of religious education in England

    OpenAIRE

    Everington, Judith

    2013-01-01

    This article presents action research conducted with student teachers of religious education in England, using theoretical propositions from Robert Jackson's interpretive approach to religious education. In the context of developing a master's-level initial teacher training course and international debate about the role of academic study in teacher education, the research investigated possibilities for using students’ exploration of theory to promote their professional development. Using a th...

  8. Advancing theories, models and measurement for an interprofessional approach to shared decision making in primary care: a study protocol.

    Science.gov (United States)

    Légaré, France; Stacey, Dawn; Graham, Ian D; Elwyn, Glyn; Pluye, Pierre; Gagnon, Marie-Pierre; Frosch, Dominick; Harrison, Margaret B; Kryworuchko, Jennifer; Pouliot, Sophie; Desroches, Sophie

    2008-01-03

    Shared decision-making (SDM) is defined as a process by which a healthcare choice is made by practitioners together with the patient. Although many diagnostic and therapeutic processes in primary care integrate more than one type of health professional, most SDM conceptual models and theories appear to be limited to the patient-physician dyad. The objectives of this study are to develop a conceptual model and propose a set of measurement tools for enhancing an interprofessional approach to SDM in primary healthcare. An inventory of SDM conceptual models, theories and measurement tools will be created. Models will be critically assessed and compared according to their strengths, limitations, acknowledgement of interprofessional roles in the process of SDM and relevance to primary care. Based on the theory analysis, a conceptual model and a set of measurements tools that could be used to enhance an interprofessional approach to SDM in primary healthcare will be proposed and pilot-tested with key stakeholders and primary healthcare teams. This study protocol is informative for researchers and clinicians interested in designing and/or conducting future studies and educating health professionals to improve how primary healthcare teams foster active participation of patients in making health decisions using a more coordinated approach.

  9. Advancing theories, models and measurement for an interprofessional approach to shared decision making in primary care: a study protocol

    Directory of Open Access Journals (Sweden)

    Frosch Dominick

    2008-01-01

    Full Text Available Abstract Background Shared decision-making (SDM is defined as a process by which a healthcare choice is made by practitioners together with the patient. Although many diagnostic and therapeutic processes in primary care integrate more than one type of health professional, most SDM conceptual models and theories appear to be limited to the patient-physician dyad. The objectives of this study are to develop a conceptual model and propose a set of measurement tools for enhancing an interprofessional approach to SDM in primary healthcare. Methods/Design An inventory of SDM conceptual models, theories and measurement tools will be created. Models will be critically assessed and compared according to their strengths, limitations, acknowledgement of interprofessional roles in the process of SDM and relevance to primary care. Based on the theory analysis, a conceptual model and a set of measurements tools that could be used to enhance an interprofessional approach to SDM in primary healthcare will be proposed and pilot-tested with key stakeholders and primary healthcare teams. Discussion This study protocol is informative for researchers and clinicians interested in designing and/or conducting future studies and educating health professionals to improve how primary healthcare teams foster active participation of patients in making health decisions using a more coordinated approach.

  10. Advancing theories, models and measurement for an interprofessional approach to shared decision making in primary care: a study protocol

    Science.gov (United States)

    Légaré, France; Stacey, Dawn; Graham, Ian D; Elwyn, Glyn; Pluye, Pierre; Gagnon, Marie-Pierre; Frosch, Dominick; Harrison, Margaret B; Kryworuchko, Jennifer; Pouliot, Sophie; Desroches, Sophie

    2008-01-01

    Background Shared decision-making (SDM) is defined as a process by which a healthcare choice is made by practitioners together with the patient. Although many diagnostic and therapeutic processes in primary care integrate more than one type of health professional, most SDM conceptual models and theories appear to be limited to the patient-physician dyad. The objectives of this study are to develop a conceptual model and propose a set of measurement tools for enhancing an interprofessional approach to SDM in primary healthcare. Methods/Design An inventory of SDM conceptual models, theories and measurement tools will be created. Models will be critically assessed and compared according to their strengths, limitations, acknowledgement of interprofessional roles in the process of SDM and relevance to primary care. Based on the theory analysis, a conceptual model and a set of measurements tools that could be used to enhance an interprofessional approach to SDM in primary healthcare will be proposed and pilot-tested with key stakeholders and primary healthcare teams. Discussion This study protocol is informative for researchers and clinicians interested in designing and/or conducting future studies and educating health professionals to improve how primary healthcare teams foster active participation of patients in making health decisions using a more coordinated approach. PMID:18173848

  11. Content-oriented Approach to Organization of Theories and Its Utilization

    Science.gov (United States)

    Hayashi, Yusuke; Bourdeau, Jacqueline; Mizoguch, Riichiro

    In spite of the fact that the relation between theory and practice is a foundation of scientific and technological development, the trend of increasing the gap between theory and practice accelerates in these years. The gap embraces a risk of distrust of science and technology. Ontological engineering as the content-oriented research is expected to contribute to the resolution of the gap. This paper presents the feasibility of organization of theoretical knowledge on ontological engineering and new-generation intelligent systems based on it through an application of ontological engineering in the area of learning/instruction support. This area also has the problem of the gap between theory and practice, and its resolution is strongly required. So far we proposed OMNIBUS ontology, which is a comprehensive ontology that covers different learning/instructional theories and paradigms, and SMARTIES, which is a theory-aware and standard-compliant authoring system for making learning/instructional scenarios based on OMNIBUS ontology. We believe the theory-awareness and standard-compliance bridge the gap between theory and practice because it links theories to practical use of standard technologies and enables practitioners to easily enjoy theoretical support while using standard technologies in practice. The following goals are set in order to achieve it; computers (1) understand a variety of learning/instructional theories based on the organization of them, (2) utilize the understanding for helping authors' learning/instructional scenario making and (3) make such theoretically sound scenarios interoperable within the framework of standard technologies. This paper suggests an ontological engineering solution to the achievement of these three goals. Although the evaluation is far from complete in terms of practical use, we believe that the results of this study address high-level technical challenges from the viewpoint of the current state of the art in the research area

  12. Hamiltonian approach to GR - Part 2: covariant theory of quantum gravity

    Science.gov (United States)

    Cremaschini, Claudio; Tessarotto, Massimo

    2017-05-01

    A non-perturbative quantum field theory of General Relativity is presented which leads to a new realization of the theory of covariant quantum gravity (CQG-theory). The treatment is founded on the recently identified Hamiltonian structure associated with the classical space-time, i.e., the corresponding manifestly covariant Hamilton equations and the related Hamilton-Jacobi theory. The quantum Hamiltonian operator and the CQG-wave equation for the corresponding CQG-state and wave function are realized in 4-scalar form. The new quantum wave equation is shown to be equivalent to a set of quantum hydrodynamic equations which warrant the consistency with the classical GR Hamilton-Jacobi equation in the semiclassical limit. A perturbative approximation scheme is developed, which permits the adoption of the harmonic oscillator approximation for the treatment of the Hamiltonian potential. As an application of the theory, the stationary vacuum CQG-wave equation is studied, yielding a stationary equation for the CQG-state in terms of the 4-scalar invariant-energy eigenvalue associated with the corresponding approximate quantum Hamiltonian operator. The conditions for the existence of a discrete invariant-energy spectrum are pointed out. This yields a possible estimate for the graviton mass together with a new interpretation about the quantum origin of the cosmological constant.

  13. Electrodynamics the field-free approach : electrostatics, magnetism, induction, relativity and field theory

    CERN Document Server

    Prytz, Kjell

    2015-01-01

    This book is intended as an undergraduate textbook in electrodynamics at basic or advanced level. The objective is to attain a general understanding of the electrodynamic theory and its basic experiments and phenomena in order to form a foundation for further studies in the engineering sciences as well as in modern quantum physics. The outline of the book is obtained from the following principles: •         Base the theory on the concept of force and mutual interaction •         Connect the theory to experiments and observations accessible to the student •         Treat the electric, magnetic and inductive phenomena cohesively with respect to force, energy, dipoles and material •         Present electrodynamics using the same principles as in the preceding mechanics course •         Aim at explaining that theory of relativity is based on the magnetic effect •         Introduce field theory after the basic phenomena have been explored in terms of forc...

  14. Hamiltonian approach to GR. Pt. 2. Covariant theory of quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Cremaschini, Claudio [Faculty of Philosophy and Science, Silesian University in Opava, Institute of Physics and Research Center for Theoretical Physics and Astrophysics, Opava (Czech Republic); Tessarotto, Massimo [University of Trieste, Department of Mathematics and Geosciences, Trieste (Italy); Faculty of Philosophy and Science, Silesian University in Opava, Institute of Physics, Opava (Czech Republic)

    2017-05-15

    A non-perturbative quantum field theory of General Relativity is presented which leads to a new realization of the theory of covariant quantum gravity (CQG-theory). The treatment is founded on the recently identified Hamiltonian structure associated with the classical space-time, i.e., the corresponding manifestly covariant Hamilton equations and the related Hamilton-Jacobi theory. The quantum Hamiltonian operator and the CQG-wave equation for the corresponding CQG-state and wave function are realized in 4-scalar form. The new quantum wave equation is shown to be equivalent to a set of quantum hydrodynamic equations which warrant the consistency with the classical GR Hamilton-Jacobi equation in the semiclassical limit. A perturbative approximation scheme is developed, which permits the adoption of the harmonic oscillator approximation for the treatment of the Hamiltonian potential. As an application of the theory, the stationary vacuum CQG-wave equation is studied, yielding a stationary equation for the CQG-state in terms of the 4-scalar invariant-energy eigenvalue associated with the corresponding approximate quantum Hamiltonian operator. The conditions for the existence of a discrete invariant-energy spectrum are pointed out. This yields a possible estimate for the graviton mass together with a new interpretation about the quantum origin of the cosmological constant. (orig.)

  15. Adopting a constructivist approach to grounded theory: implications for research design.

    Science.gov (United States)

    Mills, Jane; Bonner, Ann; Francis, Karen

    2006-02-01

    Grounded theory is a popular research methodology that is evolving to account for a range of ontological and epistemological underpinnings. Constructivist grounded theory has its foundations in relativism and an appreciation of the multiple truths and realities of subjectivism. Undertaking a constructivist enquiry requires the adoption of a position of mutuality between researcher and participant in the research process, which necessitates a rethinking of the grounded theorist's traditional role of objective observer. Key issues for constructivist grounded theorists to consider in designing their research studies are discussed in relation to developing a partnership with participants that enables a mutual construction of meaning during interviews and a meaningful reconstruction of their stories into a grounded theory model.

  16. BUSINESS MANAGEMENT THEORY DEVELOPED ON THE BASIS OF SYSTEM APPROACH AND BUSINESS ENGINEERING TOOLS

    Directory of Open Access Journals (Sweden)

    N. I. Strich

    2011-01-01

    Full Text Available Management should be carried out with due account of the system theory and using tools and opportunities offered by such modern management components as business engineering and reengineering. Main points of this theory are given along with detailed determination of business engineering and reengineering particularly efficient while determining measures needed to reorganize an enterprise (or a group of enterprises through updating its organizational structure as well as economic, personnel or other system. Out-sourcing also described in detail is considered as modern enterprise management system’s most efficient instrument.

  17. The Mean Field Theory of Spin Glasses: The Heuristic Replica Approach and Recent Rigorous Results

    Science.gov (United States)

    Parisi, Giorgio

    2009-06-01

    The mathematically correct computation of the spin glasses free energy in the infinite range limit crowns 25 years of mathematic efforts in solving this model. The exact solution of the model was found many years ago by using a heuristic approach; the results coming from the heuristic approach were crucial in deriving the mathematical results. The mathematical tools used in the rigorous approach are quite different from those of the heuristic approach. In this note we will review the heuristic approach to spin glasses in the light of the rigorous results; we will also discuss some conjectures that may be useful to derive the solution of the model in an alternative way.

  18. Generalized Vibrational Perturbation Theory for Rotovibrational Energies of Linear, Symmetric and Asymmetric Tops: Theory, Approximations, and Automated Approaches to Deal with Medium-to-Large Molecular Systems.

    Science.gov (United States)

    Piccardo, Matteo; Bloino, Julien; Barone, Vincenzo

    2015-08-05

    Models going beyond the rigid-rotor and the harmonic oscillator levels are mandatory for providing accurate theoretical predictions for several spectroscopic properties. Different strategies have been devised for this purpose. Among them, the treatment by perturbation theory of the molecular Hamiltonian after its expansion in power series of products of vibrational and rotational operators, also referred to as vibrational perturbation theory (VPT), is particularly appealing for its computational efficiency to treat medium-to-large systems. Moreover, generalized (GVPT) strategies combining the use of perturbative and variational formalisms can be adopted to further improve the accuracy of the results, with the first approach used for weakly coupled terms, and the second one to handle tightly coupled ones. In this context, the GVPT formulation for asymmetric, symmetric, and linear tops is revisited and fully generalized to both minima and first-order saddle points of the molecular potential energy surface. The computational strategies and approximations that can be adopted in dealing with GVPT computations are pointed out, with a particular attention devoted to the treatment of symmetry and degeneracies. A number of tests and applications are discussed, to show the possibilities of the developments, as regards both the variety of treatable systems and eligible methods. © 2015 Wiley Periodicals, Inc.

  19. Insights into Second Language Acquisition Theory and Different Approaches to Language Teaching

    Science.gov (United States)

    Ponniah, Joseph

    2010-01-01

    This paper attempts to review second language acquisition theory and some of the methods practiced in language classes. The review substantiates that comprehensible input as the crucial determining factor for language acquisition and consciously learned linguistic knowledge can be used only to edit the output of the acquired language sometimes…

  20. Portuguese Public University Student Satisfaction: A Stakeholder Theory-Based Approach

    Science.gov (United States)

    Mainardes, Emerson; Alves, Helena; Raposo, Mario

    2013-01-01

    In accordance with the importance of the student stakeholder to universities, the objective of this research project was to evaluate student satisfaction at Portuguese public universities as regards their self-expressed core expectations. The research was based both on stakeholder theory itself and on previous studies of university stakeholders.…

  1. Realization of Symmetry in the ERG Approach to Quantum Field Theory

    Science.gov (United States)

    Igarashi, Yuji; Itoh, Katsumi; Sonoda, Hidenori

    We review the use of the exact renormalization group forrealization of symmetry in renormalizable field theories. The review consists of three parts. In part I (sect. 2--4), we start with the perturbative construction of a renormalizable field theory as a solution of the exact renormalization group (ERG) differential equation. We show how to characterize renormalizability by an appropriate asymptotic behavior of the solution for a large momentum cutoff. Renormalized parameters are introduced to control the asymptotic behavior. In part II (sect. 5--9), we introduce two formalisms to incorporate symmetry: one by imposing the Ward-Takahashi identity, and the other by imposing the generalized Ward-Takahashi identity via sources that generate symmetry transformations. We apply the two formalisms to concrete models such as QED, YM theories, and the Wess-Zumino model in four dimensions, and the O(N) non-linear sigma model in two dimensions. We end this part with calculations of the abelian axial and chiral anomalies. In part III (sect. 10 and 11), we overview the Batalin-Vilkovisky formalism adapted to the Wilson action of a bare theory with a UV cutoff. We provide a few appendices to give details and extensions that can be omitted for the understanding of the main text. The last appendix is a quick summary for the reader's convenience.

  2. Approach to solve Slavnov-Taylor identities in nonsupersymmetric non-Abelian gauge theories

    Science.gov (United States)

    Kondrashuk, Igor; Cvetič, Gorazd; Schmidt, Ivan

    2003-03-01

    We present a way to solve Slavnov-Taylor identities in a general nonsupersymmetric theory. The solution can be parametrized by a limited number of functions of spacetime coordinates, so that all the effective fields are dressed by these functions via integral convolution. The solution restricts the ghost part of the effective action and gives predictions for the physical part of the effective action.

  3. Motivating Children with Developmental Coordination Disorder in School Physical Education: The Self-Determination Theory Approach

    Science.gov (United States)

    Katartzi, Ermioni S.; Vlachopoulos, Symeon P.

    2011-01-01

    The purpose of the current article is to highlight the potential of self-determination theory (SDT) to inform the teaching practices of physical education (PE) teachers. Such practices may enhance motivational levels for participation in physical activity (PA) for children with developmental coordination disorder (DCD). First, we review the…

  4. Extreme Value Theory Approach to Simultaneous Monitoring and Thresholding of Multiple Risk Indicators

    NARCIS (Netherlands)

    Einmahl, J.H.J.; Li, J.; Liu, R.Y.

    2006-01-01

    Risk assessments often encounter extreme settings with very few or no occurrences in reality.Inferences about risk indicators in such settings face the problem of insufficient data.Extreme value theory is particularly well suited for handling this type of problems.This paper uses a multivariate

  5. Perspectives on the Aetiology of ODD and CD: A Grounded Theory Approach

    Science.gov (United States)

    McFarland, Patrick; Sanders, James; Hagen, Bradley

    2016-01-01

    Antisocial disorders, such as oppositional defiant disorder (ODD) and conduct disorder (CD), are common reasons for youth to be seen for clinical intervention. The intent of this constructivist grounded theory study was to evaluate clinicians' perspectives on the aetiology of antisocial disorders. Six professionals from various professional…

  6. An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

    Science.gov (United States)

    Jaradat, Suhair; Qablan, Ahmad; Barham, Areej

    2011-01-01

    This paper explains how the activity theory is used as a framework to analyze the barriers to a virtual Management Information Stream (MIS) Curriculum in Jordanian schools, from both the sociocultural and pedagogical perspectives. Taking the activity system as a unit of analysis, this study documents the processes by which activities shape and are…

  7. An Experiential Approach to Teaching Communication Theory: Incorporating Contemporary Media To Clarify Theoretical Concepts.

    Science.gov (United States)

    Lamoureux, Elizabeth R.

    For professors who have been assigned the task of teaching communication theory, carefully chosen examples of films, videos, TV clips, or music can be productively used to support instruction. Both research and experience have shown that the visual and aural channels are excellent forms of amplifying, clarifying, and justifying theoretical…

  8. Random-matrix-theory approach to mesoscopic fluctuations of heat current

    Science.gov (United States)

    Schmidt, Martin; Kottos, Tsampikos; Shapiro, Boris

    2013-08-01

    We consider an ensemble of fully connected networks of N oscillators coupled harmonically with random springs and show, using random-matrix-theory considerations, that both the average phonon heat current and its variance are scale invariant and take universal values in the large N limit. These anomalous mesoscopic fluctuations is the hallmark of strong correlations between normal modes.

  9. Development and Individual Differences in Transitive Reasoning: A Fuzzy Trace Theory Approach

    Science.gov (United States)

    Bouwmeester, Samantha; Vermunt, Jeroen K.; Sijtsma, Klaas

    2007-01-01

    Fuzzy trace theory explains why children do not have to use rules of logic or premise information to infer transitive relationships. Instead, memory of the premises and performance on transitivity tasks is explained by a verbatim ability and a gist ability. Until recently, the processes involved in transitive reasoning and memory of the premises…

  10. Searching for the Self: An Identity Control Theory Approach to Triggers of Occupational Exploration

    Science.gov (United States)

    Anderson, Katherine L.; Mounts, Nina S.

    2012-01-01

    Identity control theory researchers have found evidence for two processes of identity development (identity defense and identity change) and have theorized a third process (identity exploration). College students (N = 123) self-rated as high or low in occupational identity certainty and importance received self-discrepant feedback to induce…

  11. Hamiltonian approach to GR - Part 1: covariant theory of classical gravity

    CERN Document Server

    Cremaschini, Claudio

    2016-01-01

    A challenging issue in General Relativity concerns the determination of the manifestly-covariant continuum Hamiltonian structure underlying the Einstein field equations and the related formulation of the corresponding covariant Hamilton-Jacobi theory. The task is achieved by adopting a synchronous variational principle requiring distinction between the prescribed deterministic metric tensor $\\hat{g}(r)\\equiv \\left\\{ \\hat{g}_{\\mu \

  12. Dissociation between Judgments and Outcome-Expectancy Measures in Covariation Learning: A Signal Detection Theory Approach

    Science.gov (United States)

    Perales, Jose C.; Catena, Andres; Shanks, David R.; Gonzalez, Jose A.

    2005-01-01

    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…

  13. General Theory of Nuclear Scattering: the Feshbach Kerman-Koonin Approach

    Science.gov (United States)

    Arbanas, Goran

    1995-01-01

    We extend the Feshbach-Kerman-Koonin theory (1) of low and medium energy (10-200 MeV) nucleon-nucleus scattering to describe multi-particle emission processes. The original FKK considered processes with only a single outgoing particle. However, multi-particle emission processes become significant at energies as low as 50 MeV and grow in importance at higher energies. Besides augmenting the Feshbach-Kerman-Koonin theory by adding a description of multi-particle processes, we have improved the theory at the low energy end (10-30 MeV) by uncovering a new class of multistep compound processes. We have developed a formalism within the Feshbach-Kerman-Koonin framework to describe these processes while retaining the elegant structure of the Feshbach-Kerman-Koonin theory. We use this formalism to analyze the 14 MeV ^ {93}Nb(n, n^' ) reaction and find an improved agreement between the theoretical prediction and the experimental data. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253 -1690.).

  14. "Approaches to the Teaching of Special Relativity Theory in High School and University Textbooks of Argentina"

    Science.gov (United States)

    Arriassecq, Irene; Greca, Ileana Maria

    2007-01-01

    In this work, we presented an analysis of the representation of the special relativity theory (SRT) in the most used texts in high school, Polimodal level and university level in the teaching in the Argentine Republic, from a historic, epistemological and didactic perspective. The results show that none of the analyzed texts would allow a…

  15. Making Sense of Sustainability: A Practice Theories Approach to Buying Food

    NARCIS (Netherlands)

    Brons, Anke; Oosterveer, P.J.M.

    2017-01-01

    In light of global climate change the relevance of sustainable food consumption is growing, yet access to it has not correspondingly developed. This paper addresses the issue of accessing sustainable food from a practice theories perspective. The case of students in Paris is examined by means of

  16. Overcoming the Crisis in Curriculum Theory: A Knowledge-Based Approach

    Science.gov (United States)

    Young, Michael

    2013-01-01

    This paper begins by identifying what it sees as the current crisis in curriculum theory. Following a brief history of the field, it argues that recent developments have led to it losing its object--what is taught and learned in school--and its distinctive role in the educational sciences. Arising from this brief account of the origins and nature…

  17. Sifting for Success: A Grounded Theory Approach to Sponsorship of Black Student Academic Success

    Science.gov (United States)

    Powell, Shameka N.

    2015-01-01

    Numerous findings and theories have been used to make sense of African Americans students' educational successes and experiences. Along those lines, the purpose of this study is to generate a theoretical framework of sponsorship that is grounded in Black students' educational experiences. Sponsorship is taken to be the process through which agents…

  18. Using Popular Media and a Collaborative Approach to Teaching Grounded Theory Research Methods

    Science.gov (United States)

    Creamer, Elizabeth G.; Ghoston, Michelle R.; Drape, Tiffany; Ruff, Chloe; Mukuni, Joseph

    2012-01-01

    Popular movies were used in a doctoral-level qualitative research methods course as a way to help students learn about how to collect and analyze qualitative observational data in order to develop a grounded theory. The course was designed in such a way that collaboration was central to the generation of knowledge. Using media depictions had the…

  19. Activity Theory as a Conceptual Framework for Understanding Teacher Approaches to Information and Communication Technologies

    Science.gov (United States)

    Karasavvidis, Ilias

    2009-01-01

    While the issue of teachers' perspectives on the barriers to technology use has received considerable attention, teacher concerns have not been studied in a systematic and holistic way. The present paper examines teacher concerns regarding a proposed technology-based innovation using Activity Theory as a theoretical framework. Fifty-one teachers…

  20. Social Physique Anxiety and Intention to Be Physically Active: A Self-Determination Theory Approach

    Science.gov (United States)

    Sicilia, Álvaro; Sáenz-Alvarez, Piedad; González-Cutre, David; Ferriz, Roberto

    2016-01-01

    Purpose: Based on self-determination theory, the purpose of this study was to analyze the relationship between social physique anxiety and intention to be physically active, while taking into account the mediating effects of the basic psychological needs and behavioral regulations in exercise. Method: Having obtained parents' prior consent, 390…

  1. A critical rationalist approach to organizational learning: testing the theories held by managers

    NARCIS (Netherlands)

    Faran, Doron; Wijnhoven, Alphonsus B.J.M.

    2011-01-01

    The common wisdom is that Popper's critical rationalism, a method aimed at knowledge validation through falsification of theories, is inadequate for managers in organizations. This study falsifies this argument in three phases: first, it specifies the obstructers that prevent the method from being

  2. An Attachment Theory Approach to Narrating the Faith Journey of Children of Parental Divorce

    Science.gov (United States)

    Kiesling, Chris

    2011-01-01

    This study explores the effects of parental divorce on a child's faith. Drawing from attachment theory, Granqvist and Kirkpatrick proposed two probable developmental pathways to religion. For those with secure attachment, whose cumulative experiences of sensitive, religious caregivers enhance the development of a God image as loving; belief…

  3. Relativistic many-body theory a new field-theoretical approach

    CERN Document Server

    Lindgren, Ingvar

    2016-01-01

    This revised second edition of the author’s classic text offers readers a comprehensively updated review of relativistic atomic many-body theory, covering the many developments in the field since the publication of the original title.  In particular, a new final section extends the scope to cover the evaluation of QED effects for dynamical processes. The treatment of the book is based upon quantum-field theory, and demonstrates that when the procedure is carried to all orders of perturbation theory, two-particle systems are fully compatible with the relativistically covariant Bethe-Salpeter equation. This procedure can be applied to arbitrary open-shell systems, in analogy with the standard many-body theory, and it is also applicable to systems with more than two particles. Presently existing theoretical procedures for treating atomic systems are, in several cases, insufficient to explain the accurate experimental data recently obtained, particularly for highly charged ions. The main text is divided into...

  4. Social Comparison and Body Image in Adolescence: A Grounded Theory Approach

    Science.gov (United States)

    Krayer, A.; Ingledew, D. K.; Iphofen, R.

    2008-01-01

    This study explored the use of social comparison appraisals in adolescents' lives with particular reference to enhancement appraisals which can be used to counter threats to the self. Social comparison theory has been increasingly used in quantitative research to understand the processes through which societal messages about appearance influence…

  5. Exploring multiple intelligences theory in the context of science education: An action research approach

    Science.gov (United States)

    Goodnough, Karen Catherine

    2000-10-01

    Since the publication of Frames of Mind: The Theory in Practice, multiple intelligences, theory (Gardner, 1983) has been used by practitioners in a variety of ways to make teaching and learning more meaningful. However, little attention has been focused on exploring the potential of the theory for science teaching and learning. Consequently, this research study was designed to: (1) explore Howard Gardner's theory of multiple intelligences (1983) and its merit for making science teaching and learning more meaningful; (2) provide a forum for teachers to engage in critical self-reflection about their theory and practice in science education; (3) study the process of action research in the context of science education; and (4) describe the effectiveness of collaborative action research as a framework for teacher development and curriculum development. The study reports on the experiences of four teachers (two elementary teachers, one junior high teacher, and one high school teacher) and myself, a university researcher-facilitator, as we participated in a collaborative action research project. The action research group held weekly meetings over a five-month period (January--May, 1999). The inquiry was a qualitative case study (Stake, 1994) that aimed to understand the perspectives of those directly involved. This was achieved by using multiple methods to collect data: audiotaped action research meetings, fieldnotes, semi-structured interviews, journal writing, and concept mapping. All data were analysed on an ongoing basis. Many positive outcomes resulted from the study in areas such as curriculum development, teacher development, and student learning in science. Through the process of action research, research participants became more reflective about their practice and thus, enhanced their pedagogical content knowledge (Shulman, 1987) in science. Students became more engaged in learning science, gained a greater understanding of how they learn, and experienced a

  6. Addressing weight stigma in physiotherapy: Development of a theory-driven approach to (re)thinking weight-related interactions.

    Science.gov (United States)

    Setchell, J; Gard, M; Jones, L; Watson, B M

    2017-08-01

    In this article, we propose a theory-driven approach to developing interventions for reducing weight stigma in physiotherapy and discuss the design and exploratory trial of such an intervention. Weight stigma has been identified in physiotherapists in empirical investigations. However, there has been little consideration of how this stigma might be addressed. We highlight Goffman's work on stigma that provides social and embodied understandings of stigma. Goffman's approach, however, is notably apolitical, ahistorical and lacks mechanisms for understanding power. We suggest that post-structuralist perspectives can provide insight into these areas. Drawing on these theories, we critically examine the literature on weight stigma reduction, finding that trials have largely been unsuccessful. We argue that this may be due to overly passive and simplistic intervention designs. As context-specific understandings are desirable, we examine the nature of physiotherapy to determine what might be relevant to (re)thinking weight in this profession. We then discuss the development of a multifactorial, active weight stigma intervention we trialed with eight physiotherapists. Supported by theory, the outcomes of the exploratory study suggest that physiotherapy-specific factors such as fostering professional reflexivity and improving understandings of stigma need to be incorporated into an active intervention that considers the complex determinants of weight stigma.

  7. Field theory approaches to new media practices: An introduction and some theoretical considerations

    Directory of Open Access Journals (Sweden)

    Ida Willig

    2015-05-01

    Full Text Available In this article introducing the theme of the special issue we argue that studies of new media practices might benefit from especially Pierre Bourdieu’s research on cultural production. We introduce some of the literature, which deals with the use of digital media, and which have taken steps to develop field theory in this context. Secondly, we present the four thematic articles in this issue and the articles outside the theme, which includes two translations of classic texts within communication and media research. This introduction article concludes by encouraging media scholars to embark on more studies within a field theory framework, as the ability of the comprehensive theoretical work and the ideas of a reflexive sociology is able to trigger the good questions, more than it claims to offer a complete and self-sufficient sociology of media and inherent here also new media.

  8. Group-theory approach to tailored electromagnetic properties of metamaterials: an inverse-problem solution.

    Science.gov (United States)

    Reinke, Charles M; De la Mata Luque, Teofilo M; Su, Mehmet F; Sinclair, Michael B; El-Kady, Ihab

    2011-06-01

    The problem of designing electromagnetic metamaterials is complicated by the pseudo-infinite parameter space governing such materials. We present a general solution based on group theory for the design and optimization of the electromagnetic properties of metamaterials. Using this framework, the fundamental properties of a metamaterial design, such as anisotropy or magnetic or electrical resonances, can be elucidated based on the symmetry class into which the unit cell falls. This provides a methodology for the inverse problem of design of the electromagnetic properties of a metamaterial. We also present simulations of a zia metamaterial that provides greater design flexibility for tuning the resonant properties of the device than a structure based on a simple split-ring resonator. The power of this zia element is demonstrated by creating bianisotropic, chiral, and biaxial designs using the inverse group-theory procedure outlined in this paper.

  9. Asymmetric transmission in planar chiral split-ring metamaterials: Microscopic Lorentz-theory approach

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Galynsky, Vladimir M.; Zhukovsky, Sergei

    2012-01-01

    The electronic Lorentz theory is employed to explain the optical properties of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the electromagnetic response of an individual split-ring meta-atom is determined, and the effective permittivity tensor of the me......The electronic Lorentz theory is employed to explain the optical properties of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the electromagnetic response of an individual split-ring meta-atom is determined, and the effective permittivity tensor...... of the metamaterial is calculated for normal incidence of light. Whenever the split ring lacks in-plane mirror symmetry, the corresponding permittivity tensor has a crystallographic structure of an elliptically dichroic medium, and the metamaterial exhibits optical properties of planar chiral structures. Its...

  10. A facet approach to extending the normative component of the theory of reasoned action.

    Science.gov (United States)

    Donald, I; Cooper, S R

    2001-12-01

    Using facet theory, this study addresses the weak explanatory power of normative influence in theories of reasoned action or planned behaviour. A broad normative construct is hypothesized as being characterized by two facets--social unit and behavioural modality--each of which is examined in relation to recreational drug use. A questionnaire was developed from the facets and administered to undergraduate students. Data (N = 181) were analysed using Smallest Space Analysis (SSA). The results suggest that the facets provide an adequate description of the normative construct and that personal and social normative beliefs, behavioural norms and behavioural intentions can be distinguished empirically. The results also lend partial support to Ajzen's (1988; Ajzen & Fishbein, 1977) principle of compatibility. Implications for how social influence is operationalized and conceptualized are also discussed.

  11. THEORY OF REASONED ACTION FOR CONTINUOUS IMPROVEMENT CAPABILITIES: A BEHAVIORAL APPROACH

    Directory of Open Access Journals (Sweden)

    Janaina Siegler

    2012-09-01

    Full Text Available The importance of interaction between Operations Management (OM and Human Behavior has been recently re-addressed. This paper introduced the Reasoned Action Theory suggested by Froehle and Roth (2004 to analyze Operational Capabilities exploring the suitability of this model in the context of OM. It also seeks to discuss the behavioral aspects of operational capabilities from the perspective of organizational routines. This theory was operationalized using Fishbein and Ajzen (F/A behavioral model and a multi-case strategy was employed to analyze the Continuous Improvement (CI capability. The results posit that the model explains partially the CI behavior in an operational context and some contingency variables might influence the general relationsamong the variables involved in the F/A model. Thus intention might not be the determinant variable of behavior in this context.

  12. Factors Associated With Presenteeism and Psychological Distress Using a Theory-Driven Approach.

    Science.gov (United States)

    Coutu, Marie-France; Corbière, Marc; Durand, Marie-José; Nastasia, Iuliana; Labrecque, Marie-Elise; Berbiche, Djamal; Albert, Valérie

    2015-06-01

    To test a model of presenteeism on the basis of established and emerging theories separated into organizational and individual factors that could be mediated by psychological distress. This was a Web survey of 2371 employees (response rate of 48%) of a provincial government agency. We assessed theories with validated measures for organizational and individual factors. Psychological distress was negatively associated to presenteeism, when controlling for sex, short-term work absence in the last year, and social desirability. Both individual and organizational factors were related to psychological distress. The most important factors included the presence of stress events in the preceding 6 months, extrinsic efforts (interruptions, work requirements), self-esteem as a worker, and internal amotivation. By identifying modifiable factors, our results suggest that the implementation of a work organization structure that promotes stimulation and accomplishment would reduce psychological distress and further presenteeism.

  13. Recruiting African American Children for Research: An Ecological Systems Theory Approach.

    Science.gov (United States)

    Graves, Diane; Sheldon, Jane P

    2017-04-01

    With health disparities still pervasive and persistent in the United States, medical researchers and social scientists continue to develop recruitment strategies to increase the inclusion of racial/ethnic minority groups in research and interventions. Effective methods for recruiting samples of African American participants for pediatric research may be best understood when situated within an overarching conceptual model-one that serves to organize and explain effective recruitment strategies. A theoretical framework well suited for this purpose is Bronfenbrenner's ecological systems theory, which views individuals as influencing and being influenced by (both directly and indirectly) a series of interconnected social systems. Based on the ecological systems theory and on previous research from multiple domains (e.g., medicine, psychology, public health, social work), in the current article, we review strategies for effective recruitment of African American children and adolescents for research.

  14. Inflatable actuators: an attempt for a common approach based on Treloar’s rubber elasticity theory

    Science.gov (United States)

    Tondu, Bertrand

    2018-01-01

    Inflatable actuators are defined as pressure hyperelastic vessels whose expansion is constrained for generating either movements in extension, or typical contractile movements of artificial muscles. By using Treloar’s theory of rubber elasticity, applied to thin-walled pressure vessels, we propose to determine in which conditions they can be considered as stable open-loop positioning actuators. Antagonism can be viewed as an extension of this open-loop stability principle applicable to artificial muscles as to extensible actuators. We especially show its relevance for multiple chambers pressurized cylinders and how Treloar’s theory can help to model their bending in a readable and relevant formal way. We also try to justify why we think that antagonism applied to extensible actuators can actually appear as the best way for designing miniaturized multiple degrees of freedom rubber made microactuators if, however, only a limited power is required.

  15. Trait-based approaches in plant ecology - towards a theory of form and function

    OpenAIRE

    Falster, Daniel

    2013-01-01

    Talk presented at the workshop "Trait-based approaches to Ocean Life", held in Copenhagen (Denmark) from 26-28 August 2013 at the Royal Danish Academy of Sciences and Letters (H.C. Andersens Boulevard 35, Copenhagen, Denmark). The workshop was organised by the Centre for Ocean Life. I was invited to give an overview of trait based approaches in plant ecology.

  16. Exploring EFL Learners' Perceptions of Integrated Skills Approach: A Grounded Theory

    Science.gov (United States)

    Tajzad, Maryam; Ostovar-Namaghi, Seyyed Ali

    2014-01-01

    This qualitative study aims at exploring EFL learners' perceptions of the integrated skills approach to language teaching. To this end, the researchers presented the integrated skills approach to a group of 30 participants and interviewed those who were willing to share their views and experience with the researchers. The researchers used grounded…

  17. Diagrammatic Monte Carlo approach for diagrammatic extensions of dynamical mean-field theory -- convergence analysis of the dual fermion technique

    CERN Document Server

    Gukelberger, Jan; Hafermann, Hartmut

    2016-01-01

    The dual-fermion approach provides a formally exact prescription for calculating properties of a correlated electron system in terms of a diagrammatic expansion around dynamical mean-field theory (DMFT). It can address the full range of interactions, the lowest order theory is asymptotically exact in both the weak- and strong-coupling limits, and the technique naturally incorporates long-range correlations beyond the reach of current cluster extensions to DMFT. Most practical implementations, however, neglect higher-order interaction vertices beyond two-particle scattering in the dual effective action and further truncate the diagrammatic expansion in the two-particle scattering vertex to a leading-order or ladder-type approximation. In this work we compute the dual-fermion expansion for the Hubbard model including all diagram topologies with two-particle interactions to high orders by means of a stochastic diagrammatic Monte Carlo algorithm. We use benchmarking against numerically exact Diagrammatic Determin...

  18. General atomistic approach for modeling metal-semiconductor interfaces using density functional theory and nonequilibrium Green's function

    DEFF Research Database (Denmark)

    Stradi, Daniele; Martinez, Umberto; Blom, Anders

    2016-01-01

    Metal-semiconductor contacts are a pillar of modern semiconductor technology. Historically, their microscopic understanding has been hampered by the inability of traditional analytical and numerical methods to fully capture the complex physics governing their operating principles. Here we introduce...... an atomistic approach based on density functional theory and nonequilibrium Green's function, which includes all the relevant ingredients required to model realistic metal-semiconductor interfaces and allows for a direct comparison between theory and experiments via I-Vbias curve simulations. We apply...... this method to characterize an Ag/Si interface relevant for photovoltaic applications and study the rectifying-to-Ohmic transition as a function of the semiconductor doping. We also demonstrate that the standard “activation energy” method for the analysis of I-Vbias data might be inaccurate for nonideal...

  19. Computational studies of first-Born scattering cross sections. I - Spectral properties of Bethe surfaces. II - Moment-theory approach

    Science.gov (United States)

    Margoliash, D. J.; Langhoff, P. W.

    1983-01-01

    The present investigation is concerned with the spectral properties of Bethe surfaces to establish a basis for the formulation of alternatives to the conventional computational approach. The relevant scattering cross sections and closely related Van Hove autocorrelation functions are identified as spectral (Riemann-Stieltjes) integral properties of the corresponding atomic and molecular Bethe surfaces. Evaluation of these properties for hydrogenic targets provides a basis for clarifying the ranges of validity of the static, binary-encounter, and sum-rule approximations to differential and total inelastic cross sections generally employed in place of the correct Born results. A description is provided of moment-theory methods for calculations of the high-energy electron impact-excitation and -ionization cross sections and closely related Van Hove correlation functions of atomic and molecular targets. Attention is given to aspects of the Chebyshev-Stieltjes-Markoff moment theory and the Stieltjes and Chebyshev derivatives.

  20. An Alternative Approach to Analyze Ipsative Data. Revisiting Experiential Learning Theory

    OpenAIRE

    Batista-Foguet, Joan M.; Ferrer-Rosell, Berta; Serlav?s, Ricard; Coenders, Germ?; Boyatzis, Richard E.

    2015-01-01

    The ritualistic use of statistical models regardless of the type of data actually available is a common practice across disciplines which we dare to call type zero error. Statistical models involve a series of assumptions whose existence is often neglected altogether, this is specially the case with ipsative data. This paper illustrates the consequences of this ritualistic practice within Kolb's Experiential Learning Theory (ELT) operationalized through its Learning Style Inventory (KLSI). We...

  1. Analytic approach to phase transitions and observables in Abelian gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Di Bartolo, C.; Gambini, R.; Trias, A.

    1989-05-15

    The Hamiltonian formulation of the /ital Z/(2) gauge theory at spatial dimension 2 is analyzed in gauge-invariant geometric terms by working in the loop-labeled basis of the /ital C/ representation. A consistent behavior of physical quantities near the critical point and a reasonable estimation of the transition point and the critical exponents are obtained by using a set of variables that improves the collective description proposed in previous related work.

  2. A power flow mode theory based on a system's damping distribution and power flow design approaches

    OpenAIRE

    Xiong, Ye-Ping; Xing, J. T.; Price, W.G.

    2005-01-01

    A power flow mode theory is developed to describe the natural power flow behaviour of a dynamic system based on its inherent damping distribution. The system's characteristic-damping matrix is constructed and it is shown that the eigenvalues and eigenvectors of this matrix identify natural power flow characteristics. These eigenvectors, or power flow mode vectors, are chosen as a set of base-vectors spanning the power flow space and completely describe the power flow in the system. The genera...

  3. Fuzzy Saturated Output Feedback Tracking Control for Robot Manipulators: A Singular Perturbation Theory Based Approach

    OpenAIRE

    Huashan Liu; Kuangrong Hao; Xiaobo Lai

    2011-01-01

    To deal with the problem of the output feedback tracking (OFT) control with bounded torque inputs of robot manipulators, we propose a generalized fuzzy saturated OFT controller based on singular perturbation theory. First, considering the fact that the output toque of joint actuators is limited, a general expression for a class of saturation functions is given to be applied in the control law. Second, to carry out the whole closed‐loop control with only position measurements, linear and...

  4. A General Theory of Target Identification: An Analytical Approach to Cognition, Perception, and Knowledge

    Science.gov (United States)

    1985-05-01

    emotions , hints, hunches, attempts which led to failure, etc., which reflect the subjective aspect of scientific reasearch is carefully shunned and... Zeman [3] and Prior [41 define operators Mz as "possibility" and Lz as "necessity" where Mz N LN. These can also be incorporated within the presen theory...modal logic (see Zeman [3] and Prior [4]). One defines operators LZ = T + n (for necessity truth) and MZ = T - n (for possible truth). It is easy to

  5. Linguistic Theory in Approaches to Written Error in US Composition: History and Current Directions

    OpenAIRE

    Horner, Bruce; Lu, Min-Zhan

    2017-01-01

    We trace significant shifts over the last forty years in the assumptions about language, language relations, and language learning made by US composition scholars to understand written error through their use of specific theories and findings of scholarship in linguistics, and we explore the implications of these shifts for the teaching of writing. We identify three sets of assumptions with monolingualism, and a fourth set with a break from monolingualist assumptions and an alignment with tho...

  6. [A. Weismann's germ-plasma theory: a new methodological approach to the problems of general biology].

    Science.gov (United States)

    Muzrukova, E B

    1997-01-01

    A. Weismann's theory of germ plasm is of special importance in the history of theoretical biology. Its meaning was not confined by presenting of neoperformistic ideas on the new level of science. In fact it predicted reduction division, the continuing of germ plasm and the significance of chromosomes in heredity. For the first time it brought a new methodology to the experimental genetics and the idea of interdisciplinary synthesis.

  7. TERPRETATION-BASED APPROACH TO GRAMMAR TEACHING: NEW DIRECTIONS IN THEORY AND PRACTICE

    Directory of Open Access Journals (Sweden)

    Setiono Sugiharto

    2005-01-01

    Full Text Available A substantial body of empirical research has revealed that the application of a purely communicative approach in the EFL setting is inadequate in helping learners attain high levels of grammatical competence. In fact, it has been found in the previous studies that communicative methodology produced learners with low levels of accuracy. Drawing on the contemporary literature related to grammar pedagogy, this article finds it useful to offer an alternative approach to grammar teaching in the EFL setting an approach that is based on task interpretation. This approach emphasizes the learner’s comprehension of the specific grammatical features in communicative content. Specifically, it stresses the importance of input processing rather than output processing. In so doing, the approach allows learners’ awareness of the grammatical features to develop so as to facilitate and eventually accelerate the acquisition process.

  8. Hamiltonian approach to GR. Pt. 1. Covariant theory of classical gravity

    Energy Technology Data Exchange (ETDEWEB)

    Cremaschini, Claudio [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Center for Theoretical Physics and Astrophysics, Opava (Czech Republic); Tessarotto, Massimo [University of Trieste, Department of Mathematics and Geosciences, Trieste (Italy); Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics, Opava (Czech Republic)

    2017-05-15

    A challenging issue in General Relativity concerns the determination of the manifestly covariant continuum Hamiltonian structure underlying the Einstein field equations and the related formulation of the corresponding covariant Hamilton-Jacobi theory. The task is achieved by adopting a synchronous variational principle requiring distinction between the prescribed deterministic metric tensor g(r) ≡ {g_μ_ν(r)} solution of the Einstein field equations which determines the geometry of the background space-time and suitable variational fields x ≡ {g,π} obeying an appropriate set of continuum Hamilton equations, referred to here as GR-Hamilton equations. It is shown that a prerequisite for reaching such a goal is that of casting the same equations in evolutionary form by means of a Lagrangian parametrization for a suitably reduced canonical state. As a result, the corresponding Hamilton-Jacobi theory is established in manifestly covariant form. Physical implications of the theory are discussed. These include the investigation of the structural stability of the GR-Hamilton equations with respect to vacuum solutions of the Einstein equations, assuming that wave-like perturbations are governed by the canonical evolution equations. (orig.)

  9. Promoting self-care through symptom management: a theory-based approach for nurse practitioners.

    Science.gov (United States)

    Fowler, Christopher; Kirschner, Michelle; Van Kuiken, Debra; Baas, Linda

    2007-05-01

    To present a theory of illness representation useful in clinical practice along with two case studies as examples of theory implementation. Literature review of relevant theory and associated literature, case studies from clinical practice. An individual asks several questions when experiencing a physical sensation: "Am I sick, stressed, or is this a sign of aging? If I'm sick, is the symptom connected with a disease label?" After asking these questions, the individual develops a cognitive and emotional illness representation that includes the dimensions of identity, cause, consequences, control, and timeline. This representation is guided by personal, cultural, and environmental contexts and determines coping strategies. By assessing the individual's cognitive and emotional representations of the illness, the nurse practitioner (NP) can use the common sense model of illness representation (CSM) to establish interventions and action plans helpful in decreasing distress in the management of symptoms. NPs frequently care for patients who present with very severe symptoms related to their health problem. This becomes a major challenge in effective disease management. Leventhal's CSM can be used as a framework to identify the cognitive and emotional illness representations individuals develop when acute and chronic symptoms are presented. By assessing the individual's cognitive and emotional representations of the illness, the NP will be able to use the CSM to establish interventions and action plans that will be helpful in decreasing the patient's distress in the management of symptoms.

  10. Evaluating Approaches to Teaching and Learning Chinese Vocabulary from the Learning Theories Perspective: An Experimental Case Study

    Directory of Open Access Journals (Sweden)

    Katja SIMONČIČ

    2015-06-01

    Full Text Available With Chinese language gaining more and more popularity among Slovenian students and with the growing numbers of learners of Chinese as a foreign language in Slovenia and elsewhere it is crucial to find an approach that will lead to high quality and long-term knowledge of Chinese and that will motivate learners to continue learning. We can speak of two basic approaches to teaching Chinese vocabulary: the approach that first introduces pronunciation and the approach that simultaneously introduces pronunciation and character. The key question that arises is which of the two approaches leads to high quality and long-term knowledge? To answer the question an experimental case study was carried out at Ljubljana’s Faculty of Arts in the academic year 2011/2012. The case study showed that the approach that simultaneously introduces pronunciation and character and is based on the key principles of constructivist learning theory had beneficial effects on the students in terms of motivation and quality of knowledge of Chinese vocabulary.

  11. Dramatis persona in poetical and practical approach of dramatic text in 17th century French theory of theatre

    Directory of Open Access Journals (Sweden)

    Michał Bajer

    2009-01-01

    Full Text Available The idea of the dramatis persona posited by the first French theatre theorists of the Richelieu circle, Jean Chapelain and Jules de la Mesnardiere, emerges as a quite literał implementation of the Aristotelian concepts unfolded in the sixth and fifteenth chapter of his Poetics. In a later period, the third of the aforementioned group of authors, François Hédelin d’Aubignac, dismisses the Aristotelian categories, erecting his theory upon the elements adopted from the Roman theory of rhetoric. The analysis of the Persona in classical drama theory allows to reconstruct the relation between these two 17th century dramatic approaches. The former is the traditional perspective relying on the postulations of the Aristotelian theory. The latter, which is a practical grasp, is new to the 17th century’s dramatic mindset, and was formulated by abbé d’Aubignac. Whereas the axis of poetics is the structural analysis of a work of art, it is the functioning of that work of art in the theatrical process of communication between the stage and the audience that remains the core interest of the practical approach. In this process, the rhetorical effect of presence of the dramatis persona should by created in the imagination of the spectator-auditor. The subject of analysis is common to both perspectives and the discrepancies concem merely aspects of its description. Therefore poetics and practice are neither competitive nor mutually exclusive, but can both legitimately coexist in the description of the very same work of art.

  12. Semiclassical approach to model quantum fluids using the statistical associating fluid theory for systems with potentials of variable range.

    Science.gov (United States)

    Trejos, Víctor M; Gil-Villegas, Alejandro

    2012-05-14

    Thermodynamic properties of quantum fluids are described using an extended version of the statistical associating fluid theory for potentials of variable range (SAFT-VR) that takes into account quantum corrections to the Helmholtz free energy A, based on the Wentzel-Kramers-Brillouin approximation. We present the theoretical background of this approach (SAFT-VRQ), considering two different cases depending on the continuous or discontinuous nature of the particles pair interaction. For the case of continuous potentials, we demonstrate that the standard Wigner-Kirkwood theory for quantum fluids can be derived from the de Broglie-Bohm formalism for quantum mechanics that can be incorporated within the Barker and Henderson perturbation theory for liquids in a straightforward way. When the particles interact via a discontinuous pair potential, the SAFT-VR method can be combined with the perturbation theory developed by Singh and Sinha [J. Chem. Phys. 67, 3645 (1977); and ibid. 68, 562 (1978)]. We present an analytical expression for the first-order quantum perturbation term for a square-well potential, and the theory is applied to model thermodynamic properties of hydrogen, deuterium, neon, and helium-4. Vapor-liquid equilibrium, liquid and vapor densities, isochoric and isobaric heat capacities, Joule-Thomson coefficients and inversion curves are predicted accurately with respect to experimental data. We find that quantum corrections are important for the global behavior of properties of these fluids and not only for the low-temperature regime. Predictions obtained for hydrogen compare very favorably with respect to cubic equations of state.

  13. The demonstration of a theory-based approach to the design of localized patient safety interventions

    National Research Council Canada - National Science Library

    Taylor, Natalie; Lawton, Rebecca; Slater, Beverley; Foy, Robbie

    2013-01-01

    ...) approach for co-designing patient safety interventions. We worked with three hospitals to support the implementation of evidence-based guidance to reduce the risk of feeding into misplaced nasogastric feeding tubes...

  14. The typological approach in child and family psychology: a review of theory, methods, and research.

    Science.gov (United States)

    Mandara, Jelani

    2003-06-01

    The purpose of this paper was to review the theoretical underpinnings, major concepts, and methods of the typological approach. It was argued that the typological approach offers a systematic, empirically rigorous and reliable way to synthesize the nomothetic variable-centered approach with the idiographic case-centered approach. Recent advances in cluster analysis validation make it a promising method for uncovering natural typologies. This paper also reviewed findings from personality and family studies that have revealed 3 prototypical personalities and parenting styles: Adjusted/Authoritative, Overcontrolled/Authoritarian, and Undercontrolled/Permissive. These prototypes are theorized to be synonymous with attractor basins in psychological state space. The connection between family types and personality structure as well as future directions of typological research were also discussed.

  15. Modeling Unproductive Behavior in Online Homework in Terms of Latent Student Traits: An Approach Based on Item Response Theory

    Science.gov (United States)

    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.

  16. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  17. A game theory approach for competition and cooperation among project’s subcontractors with interaction activities

    Directory of Open Access Journals (Sweden)

    Ashkan Hafezalkotob

    2017-04-01

    Full Text Available Some projects are often performed by many subcontractors that cooperate with each other and some of them are conducted by outsourcing them to several firms; so subcontractors carry out activities in competition. Appropriate trade-off between time and cost and achieving more benefit and cost saving are objectives of both models. In this paper, it is investigated that how different subcontractors of a project can cooperate to achieve more advantages if possible and how sub-contractors can compete to make the results better and find the optimum cost to minimize the time for each of them. The competition here does not mean eliminating a competitor, but the aim is to challenge the contractors in order to choose the best decision. The purpose of this study is to address the challenges in time and cost management and to find more profit allocation among subcontractors and fair competition for fair allocation as well. A model based on cooperative game theory in time/cost trade-off problem of projects is suggested and then a competition model among subcontractors based on non-cooperative game theory is proposed. A case study is rep-resented to comprehensively illustrate the problem, the cooperative techniques of cooperative game theory, and the payoff matrix of non-cooperative model among subcontractors. Results of the proposed model reveal that subcontractors can obtain higher profit from cooperation if pos-sible. When they outsource the project and compete with each other, they must consider the in-teraction activities and choose the best strategies for cost saving and gain more reward from the client. Moreover, it is found that some techniques such as Shapley value, Core, Max-Min Core, or Equal Profit Method (EPM are able to fairly assign extra profit of cooperation, and using the payoff matrix, Nash equilibrium, and Nash bargaining helps to find the optimum point to mini-mize time and cost for interaction activities state.

  18. Modern money theory and ecological tax reform: A functional finance approach to energy conservation

    Science.gov (United States)

    McConnell, Scott L. B.

    This dissertation contributes to heterodox economics by developing a theoretical and policy-relevant link that will promote the conservation of energy while driving the value of the domestic currency. The analysis relies upon the theoretical foundation of modern money theory and functional finance, which states that "taxes-drive-money" where the value of a sovereign nation's currency is imputed through the acceptance by the sovereign nation of the currency in payment of taxation. This theoretical perspective lends itself to various public policy prescriptions, such as government employment policies or the employer of last resort (ELR), which has been discussed at length elsewhere (Wray 1998; Tcherneva 2007, Forstater 2003). This research contributes to this overall program by arguing that the basis for taxation under modern money theory allows public policy makers various alternatives regarding the make-up of the tax system in place. In particular, following functional finance, taxes do not have the sole purpose of paying for government spending, but rather drive the value of the currency and may be designed to perform other functions as well, such as penalizing socially undesirable behavior. The focus in this dissertation is on the amelioration of pollution and increasing energy conservation. The research question for this dissertation is this: what federally implemented tax would best serve the multiple criteria of 1) driving the value of the currency, 2) promoting energy conservation and 3) ameliorating income and wealth disparities inherent in a monetary production economy? This dissertation provides a suggestion for such a tax that would be part of a much larger overall policy program based upon the tenets of modern money theory and functional finance. Additionally, this research seeks to provide an important theoretical contribution to the emerging Post Keynesian and ecological economics dialog.

  19. G-centers in irradiated silicon revisited: A screened hybrid density functional theory approach

    KAUST Repository

    Wang, H.

    2014-05-13

    Electronic structure calculations employing screened hybrid density functional theory are used to gain fundamental insight into the interaction of carbon interstitial (Ci) and substitutional (Cs) atoms forming the CiCs defect known as G-center in silicon (Si). The G-center is one of the most important radiation related defects in Czochralski grown Si. We systematically investigate the density of states and formation energy for different types of CiCs defects with respect to the Fermi energy for all possible charge states. Prevalence of the neutral state for the C-type defect is established.

  20. Landscape theory into logbooks: an approach in architecture and urbanism learning

    OpenAIRE

    Julieta Maria Vasconcelos Leite; Rafaela Rodrigues Alves Souza

    2016-01-01

    This text presents an educational experiment adopted with undergraduate students of Architecture and Urbanism at Universidade Federal de Pernambuco (UFPE). Our aim is to present to the students some landscape theory impressions. It is assumed that we are a whole part of the landscape and that our knowledge about it comes from how we perceive and experience it. The experiment is funded into logbooks individually elaborated by the students. Their thoughts were presented among the pictures or th...

  1. Maximum-Likelihood Approach to Topological Charge Fluctuations in Lattice Gauge Theory

    CERN Document Server

    Brower, R C; Fleming, G T; Lin, M F; Neil, E T; Osborn, J C; Rebbi, C; Rinaldi, E; Schaich, D; Schroeder, C; Voronov, G; Vranas, P; Weinberg, E; Witzel, O

    2014-01-01

    We present a novel technique for the determination of the topological susceptibility (related to the variance of the distribution of global topological charge) from lattice gauge theory simulations, based on maximum-likelihood analysis of the Markov-chain Monte Carlo time series. This technique is expected to be particularly useful in situations where relatively few tunneling events are observed. Restriction to a lattice subvolume on which topological charge is not quantized is explored, and may lead to further improvement when the global topology is poorly sampled. We test our proposed method on a set of lattice data, and compare it to traditional methods.

  2. Diffractive interface theory: nonlocal susceptibility approach to the optics of metasurfaces.

    Science.gov (United States)

    Roberts, Christopher M; Inampudi, Sandeep; Podolskiy, Viktor A

    2015-02-09

    We present a formalism for understanding the electromagnetism of metasurfaces, optically thin composite films with engineered diffraction. The technique, diffractive interface theory (DIT), takes explicit advantage of the small optical thickness of a metasurface, eliminating the need for solving for light propagation inside the film and providing a direct link between the spatial profile of a metasurface and its diffractive properties. Predictions of DIT are compared with full-wave numerical solutions of Maxwell's equations, demonstrating DIT's validity and computational advantages for optically thin structures. Applications of the DIT range from understanding of fundamentals of light-matter interaction in metasurfaces to efficient analysis of generalized refraction to metasurface optimization.

  3. Hot-electron-assisted femtochemistry at surfaces: A time-dependent density functional theory approach

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Rubio, Angel; Olsen, Thomas

    2009-01-01

    Using time-evolution time-dependent density functional theory (TDDFT) within the adiabatic local-density approximation, we study the interactions between single electrons and molecular resonances at surfaces. Our system is a nitrogen molecule adsorbed on a ruthenium surface. The surface is modeled...... at two levels of approximation, first as a simple external potential and later as a 20-atom cluster. We perform a number of calculations on an electron hitting the adsorbed molecule from inside the surface and establish a picture, where the resonance is being probed by the hot electron. This enables us...

  4. Game theory-based visual tracking approach focusing on color and texture features.

    Science.gov (United States)

    Jin, Zefenfen; Hou, Zhiqiang; Yu, Wangsheng; Chen, Chuanhua; Wang, Xin

    2017-07-20

    It is difficult for a single-feature tracking algorithm to achieve strong robustness under a complex environment. To solve this problem, we proposed a multifeature fusion tracking algorithm that is based on game theory. By focusing on color and texture features as two gamers, this algorithm accomplishes tracking by using a mean shift iterative formula to search for the Nash equilibrium of the game. The contribution of different features is always keeping the state of optical balance, so that the algorithm can fully take advantage of feature fusion. According to the experiment results, this algorithm proves to possess good performance, especially under the condition of scene variation, target occlusion, and similar interference.

  5. System safety theory and human factors approach to patient safety for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Abou, S.C. [Univ. of Minnesota, Mechanical and Industrial Engineering Dept., Duluth, Minnesota (United States)

    2011-07-01

    The research questions in this study while developing modern medical technology for safer applications of radiation therapy are - what medical and radiobiological effects and their quantitative models must be taken into account while defining the radiation risk. The uncertainty in the expression of these consequences for the delayed effects is one of the important problems the solution of which is necessary for radiation safety. The main principles of ensuring the radiation safety and the assessment of software technological risk developed on the basis of the intrinsic compatibility with safety systems theory, as an example, those which follow the concept of 'Inherent safety' are presented in this paper. (author)

  6. Teoria dell’occupazione: due impostazioni a confronto. (The theory of employment: two approaches compared

    Directory of Open Access Journals (Sweden)

    Alessandro Roncaglia

    2014-10-01

    Full Text Available Introducing the publication of a long 1956 letter by Franco Modigliani (FM to Paolo Sylos Labini (PSL on the draft of PSL’s book, Oligopoly and Technical Progress, the paper critically reviews the theoretical background of FM’s comments, showing how the pre-Keynesian roots dominate the so-called neoclassical synthesis as well as its shaky foundations. The paper also discusses FM’s interpretation of PSL’s oligopoly theory, as well as their collaboration (and differences on policy issues, such as their opposition to the 100% money wage indexation adopted in Italy from the mid-1970s to the mid-1980s. 

  7. Building Mobile Apps for Underrepresented Mental Health care Consumers: A Grounded Theory Approach

    Science.gov (United States)

    Leung, Ricky; Hastings, Julia F.; Keefe, Robert H.; Brownstein-Evans, Carol; Chan, Keith T.; Mullick, Rosemary

    2017-01-01

    Cell phone mobile application (“app”) use has risen dramatically within the past several years. Many individuals access apps to address mental health issues. Unlike individuals from privileged backgrounds, individuals from oppressed backgrounds may rely on apps rather than costly mental health treatment. To date, very little research has been published evaluating mental health apps’ effectiveness. This paper focuses on three methods through which grounded theory can facilitate app development and evaluation for people underrepresented in mental health care. Recommendations are made to advance mobile app technology that will help clinicians provide effective treatment, and consumers to realize positive treatment outcomes. PMID:29056878

  8. Transport in multilayered nanostructures the dynamical mean-field theory approach

    CERN Document Server

    Freericks, James K

    2016-01-01

    Over the last 25 years, dynamical mean-field theory (DMFT) has emerged as one of the most powerful new developments in many-body physics. Written by one of the key researchers in the field, this book presents the first comprehensive treatment of this ever-developing topic. Transport in Mutlilayered Nanostructures is varied and modern in its scope, and: A series of over 50 problems help develop the skills to allow readers to reach the level of being able to contribute to research. This book is suitable for an advanced graduate course in DMFT, and for individualized study by graduate students, postdoctoral fellows and advanced researchers wishing to enter the field.

  9. Indoor Tanning within UK Young Adults: An Extended Theory of Planned Behaviour Approach

    OpenAIRE

    Dodd, Lorna J.; Forshaw, Mark J.; Williams, Stella

    2013-01-01

    The indoor tanning industry poses a long-term public health risk. Despite the adverse health effects, indoor tanning seems to be gaining considerable popularity. The study examined indoor tanning intentions and behaviour within UK young adults using an extended theory of planned behaviour model, which included variables on “appearance reasons to tan,” “perceived susceptibility to damaging appearance,” “perceived susceptibility to health consequences,” and “tanning knowledge.” The model was su...

  10. Contradictions and power play in service encounters: an activity theory approach

    Directory of Open Access Journals (Sweden)

    Mario Eduardo Giraldo Oliveros

    Full Text Available We present a perspective on the interpersonal element of service in which economic and social collaboration takes place in real time: the service encounter. We view it as a site of conflict for power and control where social identities are anchored and collective meanings are constituted and reproduced. Our theoretical underpinning is taken from the Activity Theory (AT to shed light on the service encounter as a contradictory, political locus of tension between providers and customers (internal and external in the Higher Education (HE market.

  11. Relative Effectiveness of Two Approaches to the Teaching of Music Theory on the Achievement and Attitudes of Undergraduate Students Training as Church Musicians

    Science.gov (United States)

    Kinchen, John Dawson, III

    2012-01-01

    As a result of a perceived need to improve the music theory curricula for the preparation of church music leaders, this study compared two diverse approaches to the teaching of music theory for church music university students on achievement, attitudes, and self-preparedness. This current study was a quantitative, quasi-experimental research…

  12. Bridging Theory and Practice: Using Hip-Hop Pedagogy As A Culturally Relevant Approach In The Urban Science Classroom

    Science.gov (United States)

    Adjapong, Edmund S.

    This dissertation explores the context of urban science education as it relates to the achievement and engagement of urban youth. This study provides a framework for Hip-Hop Pedagogy, an approach to teaching and learning anchored in the creative elements of Hip-Hop culture, in STEM as an innovative approach to teaching and learning demonstrates the effect that Hip-Hop Pedagogy, as a culturally relevant approach to teaching has on teaching and learning in an urban science classroom. This study establishes practical tools and approaches, which were formed from by theory and research that transcend the traditional monolithic approaches to teaching science. Participants in this study are middle school students who attend an urban school in one of the largest school systems in the country. This research showed that as result of utilizing Hip-Hop pedagogical practices, students reported that they developed a deeper understanding of science content, students were more likely to identify as scientists, and students were provided a space and opportunities to deconstruct traditional classroom spaces and structures.

  13. Prediction of intention to continue sport in athlete students: A self-determination theory approach.

    Directory of Open Access Journals (Sweden)

    Mohammad Keshtidar

    Full Text Available Grounded on the self-determination theory (Deci & Ryan, 1985, 2000 and achievement goals theory (Ames, 1992; Nicholls, 1989, this study via structural equation modelling, predicted intention to continue in sport from goal orientations and motivations among athlete students. 268 athlete students (Mage = 21.9, in Iranian universities completed a multi-section questionnaire tapping the targeted variables. Structural equation modelling (SEM offered an overall support for the proposed model. The results showed that there are positive relationships between intention to continue in sport and both orientations as well as both motivations. A task-involving orientation emerged as a positive predictor of the autonomous motivation, while an ego-involving orientation was a positive predictor controlled motivation as well as autonomous motivation. The results also support positive paths between autonomous motivation and future intention to participate in sport. Autonomous motivation also was a positive mediator in relationship between task orientation and the intentions. As a conclusion, the implications of the task-involving orientation are discussabled in the light of its importance for the quality and potential maintenance of sport involvement among athlete students.

  14. Psychometric Properties of the Triarchic Psychopathy Measure: An Item Response Theory Approach.

    Science.gov (United States)

    Shou, Yiyun; Sellbom, Martin; Xu, Jing

    2017-02-06

    There is cumulative evidence for the cross-cultural validity of the Triarchic Psychopathy Measure (TriPM; Patrick, 2010) among non-Western populations. Recent studies using correlational and regression analyses show promising construct validity of the TriPM in Chinese samples. However, little is known about the efficiency of items in TriPM in assessing the proposed latent traits. The current study evaluated the psychometric properties of the Chinese TriPM at the item level using item response theory analyses. It also examined the measurement invariance of the TriPM between the Chinese and the U.S. student samples by applying differential item functioning analyses under the item response theory framework. The results supported the unidimensional nature of the Disinhibition and Meanness scales. Both scales had a greater level of precision in the respective underlying constructs at the positive ends. The two scales, however, had several items that were weakly associated with their respective latent traits in the Chinese student sample. Boldness, on the other hand, was found to be multidimensional, and reflected a more normally distributed range of variation. The examination of measurement bias via differential item functioning analyses revealed that a number of items of the TriPM were not equivalent across the Chinese and the U.S. Some modification and adaptation of items might be considered for improving the precision of the TriPM for Chinese participants. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Prediction of intention to continue sport in athlete students: A self-determination theory approach.

    Science.gov (United States)

    Keshtidar, Mohammad; Behzadnia, Behzad

    2017-01-01

    Grounded on the self-determination theory (Deci & Ryan, 1985, 2000) and achievement goals theory (Ames, 1992; Nicholls, 1989), this study via structural equation modelling, predicted intention to continue in sport from goal orientations and motivations among athlete students. 268 athlete students (Mage = 21.9), in Iranian universities completed a multi-section questionnaire tapping the targeted variables. Structural equation modelling (SEM) offered an overall support for the proposed model. The results showed that there are positive relationships between intention to continue in sport and both orientations as well as both motivations. A task-involving orientation emerged as a positive predictor of the autonomous motivation, while an ego-involving orientation was a positive predictor controlled motivation as well as autonomous motivation. The results also support positive paths between autonomous motivation and future intention to participate in sport. Autonomous motivation also was a positive mediator in relationship between task orientation and the intentions. As a conclusion, the implications of the task-involving orientation are discussabled in the light of its importance for the quality and potential maintenance of sport involvement among athlete students.

  16. GTRF: a game theory approach for regulating node behavior in real-time wireless sensor networks.

    Science.gov (United States)

    Lin, Chi; Wu, Guowei; Pirozmand, Poria

    2015-06-04

    The selfish behaviors of nodes (or selfish nodes) cause packet loss, network congestion or even void regions in real-time wireless sensor networks, which greatly decrease the network performance. Previous methods have focused on detecting selfish nodes or avoiding selfish behavior, but little attention has been paid to regulating selfish behavior. In this paper, a Game Theory-based Real-time & Fault-tolerant (GTRF) routing protocol is proposed. GTRF is composed of two stages. In the first stage, a game theory model named VA is developed to regulate nodes' behaviors and meanwhile balance energy cost. In the second stage, a jumping transmission method is adopted, which ensures that real-time packets can be successfully delivered to the sink before a specific deadline. We prove that GTRF theoretically meets real-time requirements with low energy cost. Finally, extensive simulations are conducted to demonstrate the performance of our scheme. Simulation results show that GTRF not only balances the energy cost of the network, but also prolongs network lifetime.

  17. A Grounded Theory Approach in a Branding Context: Challenges and lessons learnt during the research process

    Directory of Open Access Journals (Sweden)

    Anne Rindell, PhD.

    2009-06-01

    Full Text Available The purpose of this paper is to discuss challenges and lessons learnt when conducting a classic grounded theory study in a marketing context. The paper focuses on two specific challenges that were met during a specific research process. The first challenge related to positioning the study, namely, specifying“what the study is a study of”. The second challenge concerned the choice between formal or substantive theory. Both challenges were accentuated as the emerged core category concerned a phenomenon that has caught less attention in marketing, that is, the temporal dimension in corporate images. By the temporal dimension in corporate images we mean that corporate images often have roots in earlier times through consumer memories. In other words, consumers are not tabula rasa, that is, blank sheets of paper on which communication messages can be printed. Rather, consumers have a pre-understanding of the company that works as an interpretation framework for company actions in the present. The lessons learnt from this research process can be summarized as “stay faithful to the data”, “write memos on issues you reflect upon although they might be in another substantial field” as they might become useful later, and, “look into thinking in other disciplines” as disciplines do not develop equally.

  18. A basic need theory approach to problematic Internet use and the mediating effect of psychological distress.

    Science.gov (United States)

    Wong, Ting Yat; Yuen, Kenneth S L; Li, Wang On

    2014-01-01

    The Internet provides an easily accessible way to meet certain needs. Over-reliance on it leads to problematic use, which studies show can be predicted by psychological distress. Self-determination theory proposes that we all have the basic need for autonomy, competency, and relatedness. This has been shown to explain the motivations behind problematic Internet use. This study hypothesizes that individuals who are psychologically disturbed because their basic needs are not being met are more vulnerable to becoming reliant on the Internet when they seek such needs satisfaction from online activities, and tests a model in which basic needs predict problematic Internet use, fully mediated by psychological distress. Problematic Internet use, psychological distress, and basic needs satisfaction were psychometrically measured in a sample of 229 Hong Kong University students and structural equation modeling was used to test the hypothesized model. All indices showed the model has a good fit. Further, statistical testing supported a mediation effect for psychological distress between needs satisfaction and problematic Internet use. The results extend our understanding of the development and prevention of problematic Internet use based on the framework of self-determination theory. Psychological distress could be used as an early predictor, while preventing and treating problematic Internet use should emphasize the fulfillment of unmet needs.

  19. Gist Representations and Communication of Risks about HIV-AIDS: A Fuzzy-Trace Theory Approach.

    Science.gov (United States)

    Wilhelms, Evan A; Reyna, Valerie F; Brust-Renck, Priscila; Weldon, Rebecca B; Corbin, Jonathan C

    2015-01-01

    As predicted by fuzzy-trace theory, people with a range of training—from untrained adolescents to expert physicians—are susceptible to biases and errors in judgment and perception of HIV-AIDS risk. To explain why this occurs, we introduce fuzzy-trace theory as a theoretical perspective that describes these errors to be a function of knowledge deficits, gist-based representation of risk categories, retrieval failure for risk knowledge, and processing interference (e.g., base-rate neglect) in combining risk estimates. These principles explain how people perceive HIV-AIDS risk and why they take risks with potentially lethal outcomes, often despite rote (verbatim) knowledge.For example, people inappropriately generalize the wrong gist about condoms' effectiveness against fluid-borne disease to diseases that are transferred skin-to-skin, such as HPV. We also describe how variation in processing in adolescence (e.g., more verbatim processing compared to adults) can be a route to risk-taking that explains key aspects of why many people are infected with HIV in youth, as well as how interventions that emphasize bottom-line gists communicate risks effectively.

  20. Risk perception and communication in vaccination decisions: a fuzzy-trace theory approach.

    Science.gov (United States)

    Reyna, Valerie F

    2012-05-28

    The tenets of fuzzy-trace theory, along with prior research on risk perception and risk communication, are used to develop a process model of vaccination decisions in the era of Web 2.0. The theory characterizes these decisions in terms of background knowledge, dual mental representations (verbatim and gist), retrieval of values, and application of values to representations in context. Lack of knowledge interferes with the ability to extract the essential meaning, or gist, of vaccination messages. Prevention decisions have, by definition, a status quo option of "feeling okay." Psychological evidence from other prevention decisions, such as cancer screening, indicates that many people initially mentally represent their decision options in terms of simple, categorical gist: a choice between (a) a feeling-okay option (e.g., the unvaccinated status quo) versus (b) taking up preventive behavior that can have two potential categorical outcomes: feeling okay or not feeling okay. Hence, applying the same theoretical rules as used to explain framing effects and the Allais paradox, the decision to get a flu shot, for example, boils down to feeling okay (not sick) versus feeling okay (not sick) or not feeling okay (sick, side effects, or death). Because feeling okay is superior to not feeling okay (a retrieved value), this impoverished gist supports choosing not to have the flu vaccine. Anti-vaccination sources provide more coherent accounts of the gist of vaccination than official sources, filling a need to understand rare adverse outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.