Recursive renormalization group theory based subgrid modeling
Zhou, YE
1991-01-01
Advancing the knowledge and understanding of turbulence theory is addressed. Specific problems to be addressed will include studies of subgrid models to understand the effects of unresolved small scale dynamics on the large scale motion which, if successful, might substantially reduce the number of degrees of freedom that need to be computed in turbulence simulation.
System Dynamics as Model-Based Theory Building
Schwaninger, Markus; Grösser, Stefan N.
2008-01-01
This paper introduces model-based theory building as a feature of system dynamics (SD) with large potential. It presents a systemic approach to actualizing that potential, thereby opening up a new perspective on theory building in the social sciences. The question addressed is if and how SD enables the construction of high-quality theories. This contribution is based on field experiment type projects which have been focused on model-based theory building, specifically the construction of a mi...
Modeling acquaintance networks based on balance theory
Directory of Open Access Journals (Sweden)
Vukašinović Vida
2014-09-01
Full Text Available An acquaintance network is a social structure made up of a set of actors and the ties between them. These ties change dynamically as a consequence of incessant interactions between the actors. In this paper we introduce a social network model called the Interaction-Based (IB model that involves well-known sociological principles. The connections between the actors and the strength of the connections are influenced by the continuous positive and negative interactions between the actors and, vice versa, the future interactions are more likely to happen between the actors that are connected with stronger ties. The model is also inspired by the social behavior of animal species, particularly that of ants in their colony. A model evaluation showed that the IB model turned out to be sparse. The model has a small diameter and an average path length that grows in proportion to the logarithm of the number of vertices. The clustering coefficient is relatively high, and its value stabilizes in larger networks. The degree distributions are slightly right-skewed. In the mature phase of the IB model, i.e., when the number of edges does not change significantly, most of the network properties do not change significantly either. The IB model was found to be the best of all the compared models in simulating the e-mail URV (University Rovira i Virgili of Tarragona network because the properties of the IB model more closely matched those of the e-mail URV network than the other models
Fire and Heat Spreading Model Based on Cellular Automata Theory
Samartsev, A. A.; Rezchikov, A. F.; Kushnikov, V. A.; Ivashchenko, V. A.; Bogomolov, A. S.; Filimonyuk, L. Yu; Dolinina, O. N.; Kushnikov, O. V.; Shulga, T. E.; Tverdokhlebov, V. A.; Fominykh, D. S.
2018-05-01
The distinctive feature of the proposed fire and heat spreading model in premises is the reduction of the computational complexity due to the use of the theory of cellular automata with probability rules of behavior. The possibilities and prospects of using this model in practice are noted. The proposed model has a simple mechanism of integration with agent-based evacuation models. The joint use of these models could improve floor plans and reduce the time of evacuation from premises during fires.
Evaluating hydrological model performance using information theory-based metrics
The accuracy-based model performance metrics not necessarily reflect the qualitative correspondence between simulated and measured streamflow time series. The objective of this work was to use the information theory-based metrics to see whether they can be used as complementary tool for hydrologic m...
A Model of Statistics Performance Based on Achievement Goal Theory.
Bandalos, Deborah L.; Finney, Sara J.; Geske, Jenenne A.
2003-01-01
Tests a model of statistics performance based on achievement goal theory. Both learning and performance goals affected achievement indirectly through study strategies, self-efficacy, and test anxiety. Implications of these findings for teaching and learning statistics are discussed. (Contains 47 references, 3 tables, 3 figures, and 1 appendix.)…
Route Choice Model Based on Game Theory for Commuters
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Licai Yang
2016-06-01
Full Text Available The traffic behaviours of commuters may cause traffic congestion during peak hours. Advanced Traffic Information System can provide dynamic information to travellers. Due to the lack of timeliness and comprehensiveness, the provided information cannot satisfy the travellers’ needs. Since the assumptions of traditional route choice model based on Expected Utility Theory conflict with the actual situation, a route choice model based on Game Theory is proposed to provide reliable route choice to commuters in actual situation in this paper. The proposed model treats the alternative routes as game players and utilizes the precision of predicted information and familiarity of traffic condition to build a game. The optimal route can be generated considering Nash Equilibrium by solving the route choice game. Simulations and experimental analysis show that the proposed model can describe the commuters’ routine route choice decisionexactly and the provided route is reliable.
Theory-based Bayesian models of inductive learning and reasoning.
Tenenbaum, Joshua B; Griffiths, Thomas L; Kemp, Charles
2006-07-01
Inductive inference allows humans to make powerful generalizations from sparse data when learning about word meanings, unobserved properties, causal relationships, and many other aspects of the world. Traditional accounts of induction emphasize either the power of statistical learning, or the importance of strong constraints from structured domain knowledge, intuitive theories or schemas. We argue that both components are necessary to explain the nature, use and acquisition of human knowledge, and we introduce a theory-based Bayesian framework for modeling inductive learning and reasoning as statistical inferences over structured knowledge representations.
Forewarning model for water pollution risk based on Bayes theory.
Zhao, Jun; Jin, Juliang; Guo, Qizhong; Chen, Yaqian; Lu, Mengxiong; Tinoco, Luis
2014-02-01
In order to reduce the losses by water pollution, forewarning model for water pollution risk based on Bayes theory was studied. This model is built upon risk indexes in complex systems, proceeding from the whole structure and its components. In this study, the principal components analysis is used to screen out index systems. Hydrological model is employed to simulate index value according to the prediction principle. Bayes theory is adopted to obtain posterior distribution by prior distribution with sample information which can make samples' features preferably reflect and represent the totals to some extent. Forewarning level is judged on the maximum probability rule, and then local conditions for proposing management strategies that will have the effect of transforming heavy warnings to a lesser degree. This study takes Taihu Basin as an example. After forewarning model application and vertification for water pollution risk from 2000 to 2009 between the actual and simulated data, forewarning level in 2010 is given as a severe warning, which is well coincide with logistic curve. It is shown that the model is rigorous in theory with flexible method, reasonable in result with simple structure, and it has strong logic superiority and regional adaptability, providing a new way for warning water pollution risk.
Chang, CC
2012-01-01
Model theory deals with a branch of mathematical logic showing connections between a formal language and its interpretations or models. This is the first and most successful textbook in logical model theory. Extensively updated and corrected in 1990 to accommodate developments in model theoretic methods - including classification theory and nonstandard analysis - the third edition added entirely new sections, exercises, and references. Each chapter introduces an individual method and discusses specific applications. Basic methods of constructing models include constants, elementary chains, Sko
Hodges, Wilfrid
1993-01-01
An up-to-date and integrated introduction to model theory, designed to be used for graduate courses (for students who are familiar with first-order logic), and as a reference for more experienced logicians and mathematicians.
Category Theory as a Formal Mathematical Foundation for Model-Based Systems Engineering
Mabrok, Mohamed; Ryan, Michael J.
2017-01-01
In this paper, we introduce Category Theory as a formal foundation for model-based systems engineering. A generalised view of the system based on category theory is presented, where any system can be considered as a category. The objects
Cognitive performance modeling based on general systems performance theory.
Kondraske, George V
2010-01-01
General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).
Stability Analysis for Car Following Model Based on Control Theory
International Nuclear Information System (INIS)
Meng Xiang-Pei; Li Zhi-Peng; Ge Hong-Xia
2014-01-01
Stability analysis is one of the key issues in car-following theory. The stability analysis with Lyapunov function for the two velocity difference car-following model (for short, TVDM) is conducted and the control method to suppress traffic congestion is introduced. Numerical simulations are given and results are consistent with the theoretical analysis. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
A queueing theory based model for business continuity in hospitals.
Miniati, R; Cecconi, G; Dori, F; Frosini, F; Iadanza, E; Biffi Gentili, G; Niccolini, F; Gusinu, R
2013-01-01
Clinical activities can be seen as results of precise and defined events' succession where every single phase is characterized by a waiting time which includes working duration and possible delay. Technology makes part of this process. For a proper business continuity management, planning the minimum number of devices according to the working load only is not enough. A risk analysis on the whole process should be carried out in order to define which interventions and extra purchase have to be made. Markov models and reliability engineering approaches can be used for evaluating the possible interventions and to protect the whole system from technology failures. The following paper reports a case study on the application of the proposed integrated model, including risk analysis approach and queuing theory model, for defining the proper number of device which are essential to guarantee medical activity and comply the business continuity management requirements in hospitals.
HRM Model in Tourism, Based on Dialectical Systems Theory
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Simona Šarotar Žižek
2015-12-01
Full Text Available A human resources management (HRM model integrating trends in HRM with trends in tourism into a dialectical system by the Dialectical Systems Theory (DST. HRM strategy, integrated within the tourism organization’s (to’s strategy is implemented through functional strategies helping their users to achieve a requisitely holistic (rh HRM strategy replacing the prevailing one-sided ones. to’s strategy covers: employees (1 planning, (2 acquisition and selection, (3 development and training, (4 diversity management, (5 teamwork and creativity, (6 motivation and rewarding, (7 stress reduction and health, (8 relationships, (9 personal holism, (10 well-being, (11 work and results assessment; etc. Everyone matters; their synergy is crucial. An innovated HRM model for TOS, which applies employees’, organizations’ rh and integrates new knowledge about HRM. HRM belongs to central managers’ tools. Their HRM must be adapted for TOS, where employees are crucial.
A system-theory-based model for monthly river runoff forecasting: model calibration and optimization
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Wu Jianhua
2014-03-01
Full Text Available River runoff is not only a crucial part of the global water cycle, but it is also an important source for hydropower and an essential element of water balance. This study presents a system-theory-based model for river runoff forecasting taking the Hailiutu River as a case study. The forecasting model, designed for the Hailiutu watershed, was calibrated and verified by long-term precipitation observation data and groundwater exploitation data from the study area. Additionally, frequency analysis, taken as an optimization technique, was applied to improve prediction accuracy. Following model optimization, the overall relative prediction errors are below 10%. The system-theory-based prediction model is applicable to river runoff forecasting, and following optimization by frequency analysis, the prediction error is acceptable.
Model-Based Battery Management Systems: From Theory to Practice
Pathak, Manan
Lithium-ion batteries are now extensively being used as the primary storage source. Capacity and power fade, and slow recharging times are key issues that restrict its use in many applications. Battery management systems are critical to address these issues, along with ensuring its safety. This dissertation focuses on exploring various control strategies using detailed physics-based electrochemical models developed previously for lithium-ion batteries, which could be used in advanced battery management systems. Optimal charging profiles for minimizing capacity fade based on SEI-layer formation are derived and the benefits of using such control strategies are shown by experimentally testing them on a 16 Ah NMC-based pouch cell. This dissertation also explores different time-discretization strategies for non-linear models, which gives an improved order of convergence for optimal control problems. Lastly, this dissertation also explores a physics-based model for predicting the linear impedance of a battery, and develops a freeware that is extremely robust and computationally fast. Such a code could be used for estimating transport, kinetic and material properties of the battery based on the linear impedance spectra.
Modeling Sensor Reliability in Fault Diagnosis Based on Evidence Theory
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Kaijuan Yuan
2016-01-01
Full Text Available Sensor data fusion plays an important role in fault diagnosis. Dempster–Shafer (D-R evidence theory is widely used in fault diagnosis, since it is efficient to combine evidence from different sensors. However, under the situation where the evidence highly conflicts, it may obtain a counterintuitive result. To address the issue, a new method is proposed in this paper. Not only the statistic sensor reliability, but also the dynamic sensor reliability are taken into consideration. The evidence distance function and the belief entropy are combined to obtain the dynamic reliability of each sensor report. A weighted averaging method is adopted to modify the conflict evidence by assigning different weights to evidence according to sensor reliability. The proposed method has better performance in conflict management and fault diagnosis due to the fact that the information volume of each sensor report is taken into consideration. An application in fault diagnosis based on sensor fusion is illustrated to show the efficiency of the proposed method. The results show that the proposed method improves the accuracy of fault diagnosis from 81.19% to 89.48% compared to the existing methods.
Models for Theory-Based M.A. and Ph.D. Programs.
Botan, Carl; Vasquez, Gabriel
1999-01-01
Presents work accomplished at the 1998 National Communication Association Summer Conference. Outlines reasons for theory-based education in public relations. Presents an integrated model of student outcomes, curriculum, pedagogy, and assessment for theory-based master's and doctoral programs, including assumptions made and rationale for such…
Collective learning modeling based on the kinetic theory of active particles
Burini, D.; De Lillo, S.; Gibelli, L.
2016-03-01
This paper proposes a systems approach to the theory of perception and learning in populations composed of many living entities. Starting from a phenomenological description of these processes, a mathematical structure is derived which is deemed to incorporate their complexity features. The modeling is based on a generalization of kinetic theory methods where interactions are described by theoretical tools of game theory. As an application, the proposed approach is used to model the learning processes that take place in a classroom.
Theory and theory-based models for the pedestal, edge stability and ELMs in tokamaks
International Nuclear Information System (INIS)
Guzdar, P.N.; Mahajan, S.M.; Yoshida, Z.; Dorland, W.; Rogers, B.N.; Bateman, G.; Kritz, A.H.; Pankin, A.; Voitsekhovitch, I.; Onjun, T.; Snyder, S.
2005-01-01
Theories for equilibrium and stability of H-modes, and models for use within integrated modeling codes with the objective of predicting the height, width and shape of the pedestal at the edge of H-mode plasmas in tokamaks, as well as the onset and frequency of Edge Localized Modes (ELMs), are developed. A theory model for relaxed plasma states with flow, which uses two-fluid Hall-MHD equations, predicts that the natural scale length of the pedestal is the ion skin depth and the pedestal width is larger than the ion poloidal gyro-radius, in agreement with experimental observations. Computations with the GS2 code are used to identify micro-instabilities, such as electron drift waves, that survive the strong flow shear, diamagnetic flows, and magnetic shear that are characteristic of the pedestal. Other instabilities on the pedestal and gyro-radius scale, such as the Kelvin-Helmholtz instability, are also investigated. Time-dependent integrated modeling simulations are used to follow the transition from L-mode to H-mode and the subsequent evolution of ELMs as the heating power is increased. The flow shear stabilization that produces the transport barrier at the edge of the plasma reduces different modes of anomalous transport and, consequently, different channels of transport at different rates. ELM crashes are triggered in the model by pressure-driven ballooning modes or by current-driven peeling modes. (author)
Time dependent mechanical modeling for polymers based on network theory
Energy Technology Data Exchange (ETDEWEB)
Billon, Noëlle [MINES ParisTech, PSL-Research University, CEMEF – Centre de mise en forme des matériaux, CNRS UMR 7635, CS 10207 rue Claude Daunesse 06904 Sophia Antipolis Cedex (France)
2016-05-18
Despite of a lot of attempts during recent years, complex mechanical behaviour of polymers remains incompletely modelled, making industrial design of structures under complex, cyclic and hard loadings not totally reliable. The non linear and dissipative viscoelastic, viscoplastic behaviour of those materials impose to take into account non linear and combined effects of mechanical and thermal phenomena. In this view, a visco-hyperelastic, viscoplastic model, based on network description of the material has recently been developed and designed in a complete thermodynamic frame in order to take into account those main thermo-mechanical couplings. Also, a way to account for coupled effects of strain-rate and temperature was suggested. First experimental validations conducted in the 1D limit on amorphous rubbery like PMMA in isothermal conditions led to pretty goods results. In this paper a more complete formalism is presented and validated in the case of a semi crystalline polymer, a PA66 and a PET (either amorphous or semi crystalline) are used. Protocol for identification of constitutive parameters is described. It is concluded that this new approach should be the route to accurately model thermo-mechanical behaviour of polymers using a reduced number of parameters of some physical meaning.
Seezink, Audrey; Poell, Rob; Kirschner, Paul A.
2009-01-01
Seezink, A., Poell, R. F., & Kirschner, P. A. (2009). Teachers' individual action theories about competence-based education: The value of the cognitive apprenticeship model. Journal of Vocational Education & Training, 61, 203-215.
[Modeling continuous scaling of NDVI based on fractal theory].
Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng
2013-07-01
Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing.
Buckled graphene: A model study based on density functional theory
Khan, Yasser
2010-09-01
We make use of ab initio calculations within density functional theory to investigate the influence of buckling on the electronic structure of single layer graphene. Our systematic study addresses a wide range of bond length and bond angle variations in order to obtain insights into the energy scale associated with the formation of ripples in a graphene sheet. © 2010 Elsevier B.V. All rights reserved.
Buckled graphene: A model study based on density functional theory
Khan, Yasser; Mukaddam, Mohsin Ahmed; Schwingenschlö gl, Udo
2010-01-01
We make use of ab initio calculations within density functional theory to investigate the influence of buckling on the electronic structure of single layer graphene. Our systematic study addresses a wide range of bond length and bond angle variations in order to obtain insights into the energy scale associated with the formation of ripples in a graphene sheet. © 2010 Elsevier B.V. All rights reserved.
A new safety assessment model for shallow land burial of LLW based on multicomponent sorption theory
International Nuclear Information System (INIS)
Katoh, N.; Asano, T.; Tasaka, H.
1984-01-01
A new model on the radionuclide migration in underground environment is developed based on ''multicomponent sorption theory''. The model is capable of predicting the behaviors of the coexisting materials in soil-ground water system as ''multicomponent sorption phenomena'' and also predicting the radinuclide migration affected by the changes of concentrations of coexisting materials. The model is not a ''statistical model'' but a ''chemical model'' based on the ''ion exchange theory'' and ''adsorption theory''. Additionally, the model is a ''kinetic model'' capable of estimating the effect of ''rate of sorption'' on the radionuclide migration. The validity of the model was checked by the results of column experiments for sorption. Finally, sample calculations on the radionuclide migration in reference shallow land burial site were carried out for demonstration
Consumption-based macroeconomic models of asset pricing theory
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Đorđević Marija
2016-01-01
Full Text Available The family of consumptionbased asset pricing models yields a stochastic discount factor proportional to the marginal rate of intertemporal substitution of consumption. In examining the empirical performance of this class of models, several puzzles are discovered. In this literature review we present the canonical model, the corresponding empirical tests, and different extensions to this model that propose a resolution of these puzzles.
Agent-based models for higher-order theory of mind
de Weerd, Harmen; Verbrugge, Rineke; Verheij, Bart; Kamiński, Bogumił; Koloch, Grzegorz
2014-01-01
Agent-based models are a powerful tool for explaining the emergence of social phenomena in a society. In such models, individual agents typically have little cognitive ability. In this paper, we model agents with the cognitive ability to make use of theory of mind. People use this ability to reason
Surface Water Quality Evaluation Based on a Game Theory-Based Cloud Model
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Bing Yang
2018-04-01
Full Text Available Water quality evaluation is an essential measure to analyze water quality. However, excessive randomness and fuzziness affect the process of evaluation, thus reducing the accuracy of evaluation. Therefore, this study proposed a cloud model for evaluating the water quality to alleviate this problem. Analytic hierarchy process and entropy theory were used to calculate the subjective weight and objective weight, respectively, and then they were coupled as a combination weight (CW via game theory. The proposed game theory-based cloud model (GCM was then applied to the Qixinggang section of the Beijiang River. The results show that the CW ranks fecal coliform as the most important factor, followed by total nitrogen and total phosphorus, while biochemical oxygen demand and fluoride were considered least important. There were 19 months (31.67% at grade I, 39 months (65.00% at grade II, and one month at grade IV and grade V during 2010–2014. A total of 52 months (86.6% of GCM were identical to the comprehensive evaluation result (CER. The obtained water quality grades of GCM are close to the grades of the analytic hierarchy process weight (AHPW due to the weight coefficient of AHPW set to 0.7487. Generally, one or two grade gaps exist among the results of the three groups of weights, suggesting that the index weight is not particularly sensitive to the cloud model. The evaluated accuracy of water quality can be improved by modifying the quantitative boundaries. This study could provide a reference for water quality evaluation, prevention, and improvement of water quality assessment and other applications.
An information theory-based approach to modeling the information processing of NPP operators
International Nuclear Information System (INIS)
Kim, Jong Hyun; Seong, Poong Hyun
2002-01-01
This paper proposes a quantitative approach to modeling the information processing of NPP operators. The aim of this work is to derive the amount of the information processed during a certain control task. The focus will be on i) developing a model for information processing of NPP operators and ii) quantifying the model. To resolve the problems of the previous approaches based on the information theory, i.e. the problems of single channel approaches, we primarily develop the information processing model having multiple stages, which contains information flows. Then the uncertainty of the information is quantified using the Conant's model, a kind of information theory
Collective learning modeling based on the kinetic theory of active particles.
Burini, D; De Lillo, S; Gibelli, L
2016-03-01
This paper proposes a systems approach to the theory of perception and learning in populations composed of many living entities. Starting from a phenomenological description of these processes, a mathematical structure is derived which is deemed to incorporate their complexity features. The modeling is based on a generalization of kinetic theory methods where interactions are described by theoretical tools of game theory. As an application, the proposed approach is used to model the learning processes that take place in a classroom. Copyright © 2015 Elsevier B.V. All rights reserved.
Theory-Based Stakeholder Evaluation
Hansen, Morten Balle; Vedung, Evert
2010-01-01
This article introduces a new approach to program theory evaluation called theory-based stakeholder evaluation or the TSE model for short. Most theory-based approaches are program theory driven and some are stakeholder oriented as well. Practically, all of the latter fuse the program perceptions of the various stakeholder groups into one unitary…
Computer Support of Groups: Theory-Based Models for GDSS Research
V. Srinivasan Rao; Sirkka L. Jarvenpaa
1991-01-01
Empirical research in the area of computer support of groups is characterized by inconsistent results across studies. This paper attempts to reconcile the inconsistencies by linking the ad hoc reasoning in the studies to existing theories of communication, minority influence and human information processing. Contingency models are then presented based on the theories discussed. The paper concludes by discussing the linkages between the current work and other recently published integrations of...
International Nuclear Information System (INIS)
Wang, Lin; Liu, Xiongwei; Renevier, Nathalie; Stables, Matthew; Hall, George M.
2014-01-01
Due to the increasing size and flexibility of large wind turbine blades, accurate and reliable aeroelastic modelling is playing an important role for the design of large wind turbines. Most existing aeroelastic models are linear models based on assumption of small blade deflections. This assumption is not valid anymore for very flexible blade design because such blades often experience large deflections. In this paper, a novel nonlinear aeroelastic model for large wind turbine blades has been developed by combining BEM (blade element momentum) theory and mixed-form formulation of GEBT (geometrically exact beam theory). The nonlinear aeroelastic model takes account of large blade deflections and thus greatly improves the accuracy of aeroelastic analysis of wind turbine blades. The nonlinear aeroelastic model is implemented in COMSOL Multiphysics and validated with a series of benchmark calculation tests. The results show that good agreement is achieved when compared with experimental data, and its capability of handling large deflections is demonstrated. Finally the nonlinear aeroelastic model is applied to aeroelastic modelling of the parked WindPACT 1.5 MW baseline wind turbine, and reduced flapwise deflection from the nonlinear aeroelastic model is observed compared to the linear aeroelastic code FAST (Fatigue, Aerodynamics, Structures, and Turbulence). - Highlights: • A novel nonlinear aeroelastic model for wind turbine blades is developed. • The model takes account of large blade deflections and geometric nonlinearities. • The model is reliable and efficient for aeroelastic modelling of wind turbine blades. • The accuracy of the model is verified by a series of benchmark calculation tests. • The model provides more realistic aeroelastic modelling than FAST (Fatigue, Aerodynamics, Structures, and Turbulence)
Derivative Trade Optimizing Model Utilizing GP Based on Behavioral Finance Theory
Matsumura, Koki; Kawamoto, Masaru
This paper proposed a new technique which makes the strategy trees for the derivative (option) trading investment decision based on the behavioral finance theory and optimizes it using evolutionary computation, in order to achieve high profitability. The strategy tree uses a technical analysis based on a statistical, experienced technique for the investment decision. The trading model is represented by various technical indexes, and the strategy tree is optimized by the genetic programming(GP) which is one of the evolutionary computations. Moreover, this paper proposed a method using the prospect theory based on the behavioral finance theory to set psychological bias for profit and deficit and attempted to select the appropriate strike price of option for the higher investment efficiency. As a result, this technique produced a good result and found the effectiveness of this trading model by the optimized dealings strategy.
A game theory-based trust measurement model for social networks.
Wang, Yingjie; Cai, Zhipeng; Yin, Guisheng; Gao, Yang; Tong, Xiangrong; Han, Qilong
2016-01-01
In social networks, trust is a complex social network. Participants in online social networks want to share information and experiences with as many reliable users as possible. However, the modeling of trust is complicated and application dependent. Modeling trust needs to consider interaction history, recommendation, user behaviors and so on. Therefore, modeling trust is an important focus for online social networks. We propose a game theory-based trust measurement model for social networks. The trust degree is calculated from three aspects, service reliability, feedback effectiveness, recommendation credibility, to get more accurate result. In addition, to alleviate the free-riding problem, we propose a game theory-based punishment mechanism for specific trust and global trust, respectively. We prove that the proposed trust measurement model is effective. The free-riding problem can be resolved effectively through adding the proposed punishment mechanism.
Liu, Hong; Zhu, Jingping; Wang, Kai
2015-08-24
The geometrical attenuation model given by Blinn was widely used in the geometrical optics bidirectional reflectance distribution function (BRDF) models. Blinn's geometrical attenuation model based on symmetrical V-groove assumption and ray scalar theory causes obvious inaccuracies in BRDF curves and negatives the effects of polarization. Aiming at these questions, a modified polarized geometrical attenuation model based on random surface microfacet theory is presented by combining of masking and shadowing effects and polarized effect. The p-polarized, s-polarized and unpolarized geometrical attenuation functions are given in their separate expressions and are validated with experimental data of two samples. It shows that the modified polarized geometrical attenuation function reaches better physical rationality, improves the precision of BRDF model, and widens the applications for different polarization.
An economic theory-based explanatory model of agricultural land-use patterns
Diogo, V.; Koomen, E.; Kuhlman, T.
2015-01-01
An economic theory-based land-use modelling framework is presented aiming to explain the causal link between economic decisions and resulting spatial patterns of agricultural land use. The framework assumes that farmers pursue utility maximisation in agricultural production systems, while
Assessment of Prevalence of Persons with Down Syndrome: A Theory-Based Demographic Model
de Graaf, Gert; Vis, Jeroen C.; Haveman, Meindert; van Hove, Geert; de Graaf, Erik A. B.; Tijssen, Jan G. P.; Mulder, Barbara J. M.
2011-01-01
Background: The Netherlands are lacking reliable empirical data in relation to the development of birth and population prevalence of Down syndrome. For the UK and Ireland there are more historical empirical data available. A theory-based model is developed for predicting Down syndrome prevalence in the Netherlands from the 1950s onwards. It is…
Droop Control with an Adjustable Complex Virtual Impedance Loop based on Cloud Model Theory
DEFF Research Database (Denmark)
Li, Yan; Shuai, Zhikang; Xu, Qinming
2016-01-01
Droop control framework with an adjustable virtual impedance loop is proposed in this paper, which is based on the cloud model theory. The proposed virtual impedance loop includes two terms: a negative virtual resistor and an adjustable virtual inductance. The negative virtual resistor term...... sometimes. The cloud model theory is applied to get online the changing line impedance value, which relies on the relevance of the reactive power responding the changing line impedance. The verification of the proposed control strategy is done according to the simulation in a low voltage microgrid in Matlab....
A conceptual model of social entrepreneurial intention based on the social cognitive career theory
Directory of Open Access Journals (Sweden)
Anh T.P. Tran
2017-01-01
Full Text Available Purpose - Entrepreneurial intention plays a major role in entrepreneurship academia and practice. However, little is known about the intentions of entrepreneurs in the social area of venture creation. This paper aims to formulate a well-organized model of social entrepreneurial intention. Design/methodology/approach - The paper draws on intention models in entrepreneurship literature in general and social entrepreneurship in particular to identify gaps. Based on these findings, a new conceptual model is formulated. Findings - There is no research to be found which uses the social cognitive career theory (SCCT to explain about an individual’s intention to become a social entrepreneur, although this theory is recently suggested as an inclusive framework for entrepreneurial intention (Doan Winkel et al., 2011. It is also supportive by the empirical research of Segal et al. (2002. Therefore, a conceptual model of entrepreneurial intention in the field of social entrepreneurship is formulated based on adapting and extending the SCCT. Originality/value - The paper contributes to the social entrepreneurship literature by providing new insights about social entrepreneurial intention. The result has important implications for theory and practice. In theory, it is the first model offering the SCCT as the background of formation for social entrepreneurial intention, with a distinct perspective of social entrepreneurship as a career. It raises a future direction for researchers to test this model. In practice, this framework provides a broad view of factors that could contribute to the success of the would-be a social entrepreneur.
Category Theory as a Formal Mathematical Foundation for Model-Based Systems Engineering
Mabrok, Mohamed
2017-01-09
In this paper, we introduce Category Theory as a formal foundation for model-based systems engineering. A generalised view of the system based on category theory is presented, where any system can be considered as a category. The objects of the category represent all the elements and components of the system and the arrows represent the relations between these components (objects). The relationship between these objects are the arrows or the morphisms in the category. The Olog is introduced as a formal language to describe a given real-world situation description and requirement writing. A simple example is provided.
Comparison of ITER performance predicted by semi-empirical and theory-based transport models
International Nuclear Information System (INIS)
Mukhovatov, V.; Shimomura, Y.; Polevoi, A.
2003-01-01
The values of Q=(fusion power)/(auxiliary heating power) predicted for ITER by three different methods, i.e., transport model based on empirical confinement scaling, dimensionless scaling technique, and theory-based transport models are compared. The energy confinement time given by the ITERH-98(y,2) scaling for an inductive scenario with plasma current of 15 MA and plasma density 15% below the Greenwald value is 3.6 s with one technical standard deviation of ±14%. These data are translated into a Q interval of [7-13] at the auxiliary heating power P aux = 40 MW and [7-28] at the minimum heating power satisfying a good confinement ELMy H-mode. Predictions of dimensionless scalings and theory-based transport models such as Weiland, MMM and IFS/PPPL overlap with the empirical scaling predictions within the margins of uncertainty. (author)
Soft Measurement Modeling Based on Chaos Theory for Biochemical Oxygen Demand (BOD
Directory of Open Access Journals (Sweden)
Junfei Qiao
2016-12-01
Full Text Available The precision of soft measurement for biochemical oxygen demand (BOD is always restricted due to various factors in the wastewater treatment plant (WWTP. To solve this problem, a new soft measurement modeling method based on chaos theory is proposed and is applied to BOD measurement in this paper. Phase space reconstruction (PSR based on Takens embedding theorem is used to extract more information from the limited datasets of the chaotic system. The WWTP is first testified as a chaotic system by the correlation dimension (D, the largest Lyapunov exponents (λ1, the Kolmogorov entropy (K of the BOD and other water quality parameters time series. Multivariate chaotic time series modeling method with principal component analysis (PCA and artificial neural network (ANN is then adopted to estimate the value of the effluent BOD. Simulation results show that the proposed approach has higher accuracy and better prediction ability than the corresponding modeling approaches not based on chaos theory.
Agent-based modeling: a new approach for theory building in social psychology.
Smith, Eliot R; Conrey, Frederica R
2007-02-01
Most social and psychological phenomena occur not as the result of isolated decisions by individuals but rather as the result of repeated interactions between multiple individuals over time. Yet the theory-building and modeling techniques most commonly used in social psychology are less than ideal for understanding such dynamic and interactive processes. This article describes an alternative approach to theory building, agent-based modeling (ABM), which involves simulation of large numbers of autonomous agents that interact with each other and with a simulated environment and the observation of emergent patterns from their interactions. The authors believe that the ABM approach is better able than prevailing approaches in the field, variable-based modeling (VBM) techniques such as causal modeling, to capture types of complex, dynamic, interactive processes so important in the social world. The article elaborates several important contrasts between ABM and VBM and offers specific recommendations for learning more and applying the ABM approach.
Chen, Chung-De
2018-04-01
In this paper, a distributed parameter electromechanical model for bimorph piezoelectric energy harvesters based on the refined zigzag theory (RZT) is developed. In this model, the zigzag function is incorporated into the axial displacement, and the zigzag distribution of the displacement between the adjacent layers of the bimorph structure can be considered. The governing equations, including three equations of motions and one equation of circuit, are derived using Hamilton’s principle. The natural frequency, its corresponding modal function and the steady state response of the base excitation motion are given in exact forms. The presented results are benchmarked with the finite element method and two beam theories, the first-order shear deformation theory and the classical beam theory. Comparing examples shows that the RZT provides predictions of output voltage and generated power at high accuracy, especially for the case of a soft middle layer. Variation of the parameters, such as the beam thickness, excitation frequencies and the external electrical loads, is investigated and its effects on the performance of the energy harvesters are studied by using the RZT developed in this paper. Based on this refined theory, analysts and engineers can capture more details on the electromechanical behavior of piezoelectric harvesters.
Directory of Open Access Journals (Sweden)
Andrea Nobili
2015-01-01
Full Text Available Three generalizations of the Timoshenko beam model according to the linear theory of micropolar elasticity or its special cases, that is, the couple stress theory or the modified couple stress theory, recently developed in the literature, are investigated and compared. The analysis is carried out in a variational setting, making use of Hamilton’s principle. It is shown that both the Timoshenko and the (possibly modified couple stress models are based on a microstructural kinematics which is governed by kinosthenic (ignorable terms in the Lagrangian. Despite their difference, all models bring in a beam-plane theory only one microstructural material parameter. Besides, the micropolar model formally reduces to the couple stress model upon introducing the proper constraint on the microstructure kinematics, although the material parameter is generally different. Line loading on the microstructure results in a nonconservative force potential. Finally, the Hamiltonian form of the micropolar beam model is derived and the canonical equations are presented along with their general solution. The latter exhibits a general oscillatory pattern for the microstructure rotation and stress, whose behavior matches the numerical findings.
Liu, Yanbin; Liu, Mengying; Sun, Peihua
2014-01-01
A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods.
Fukuhara, Hirotaka; Kamata, Akihito
2011-01-01
A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…
Ewing, E Stephanie Krauthamer; Diamond, Guy; Levy, Suzanne
2015-01-01
Attachment-Based Family Therapy (ABFT) is a manualized family-based intervention designed for working with depressed adolescents, including those at risk for suicide, and their families. It is an empirically informed and supported treatment. ABFT has its theoretical underpinnings in attachment theory and clinical roots in structural family therapy and emotion focused therapies. ABFT relies on a transactional model that aims to transform the quality of adolescent-parent attachment, as a means of providing the adolescent with a more secure relationship that can support them during challenging times generally, and the crises related to suicidal thinking and behavior, specifically. This article reviews: (1) the theoretical foundations of ABFT (attachment theory, models of emotional development); (2) the ABFT clinical model, including training and supervision factors; and (3) empirical support.
Cao, Xianzhong; Wang, Feng; Zheng, Zhongmei
The paper reports an educational experiment on the e-Learning instructional design model based on Cognitive Flexibility Theory, the experiment were made to explore the feasibility and effectiveness of the model in promoting the learning quality in ill-structured domain. The study performed the experiment on two groups of students: one group learned through the system designed by the model and the other learned by the traditional method. The results of the experiment indicate that the e-Learning designed through the model is helpful to promote the intrinsic motivation, learning quality in ill-structured domains, ability to resolve ill-structured problem and creative thinking ability of the students.
Theory and experiments in model-based space system anomaly management
Kitts, Christopher Adam
This research program consists of an experimental study of model-based reasoning methods for detecting, diagnosing and resolving anomalies that occur when operating a comprehensive space system. Using a first principles approach, several extensions were made to the existing field of model-based fault detection and diagnosis in order to develop a general theory of model-based anomaly management. Based on this theory, a suite of algorithms were developed and computationally implemented in order to detect, diagnose and identify resolutions for anomalous conditions occurring within an engineering system. The theory and software suite were experimentally verified and validated in the context of a simple but comprehensive, student-developed, end-to-end space system, which was developed specifically to support such demonstrations. This space system consisted of the Sapphire microsatellite which was launched in 2001, several geographically distributed and Internet-enabled communication ground stations, and a centralized mission control complex located in the Space Technology Center in the NASA Ames Research Park. Results of both ground-based and on-board experiments demonstrate the speed, accuracy, and value of the algorithms compared to human operators, and they highlight future improvements required to mature this technology.
A Bayes Theory-Based Modeling Algorithm to End-to-end Network Traffic
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Zhao Hong-hao
2016-01-01
Full Text Available Recently, network traffic has exponentially increasing due to all kind of applications, such as mobile Internet, smart cities, smart transportations, Internet of things, and so on. the end-to-end network traffic becomes more important for traffic engineering. Usually end-to-end traffic estimation is highly difficult. This paper proposes a Bayes theory-based method to model the end-to-end network traffic. Firstly, the end-to-end network traffic is described as a independent identically distributed normal process. Then the Bases theory is used to characterize the end-to-end network traffic. By calculating the parameters, the model is determined correctly. Simulation results show that our approach is feasible and effective.
A Bayes Theory-Based Modeling Algorithm to End-to-end Network Traffic
Zhao Hong-hao; Meng Fan-bo; Zhao Si-wen; Zhao Si-hang; Lu Yi
2016-01-01
Recently, network traffic has exponentially increasing due to all kind of applications, such as mobile Internet, smart cities, smart transportations, Internet of things, and so on. the end-to-end network traffic becomes more important for traffic engineering. Usually end-to-end traffic estimation is highly difficult. This paper proposes a Bayes theory-based method to model the end-to-end network traffic. Firstly, the end-to-end network traffic is described as a independent identically distrib...
Decision-making model of generation technology under uncertainty based on real option theory
International Nuclear Information System (INIS)
Ming, Zeng; Ping, Zhang; Shunkun, Yu; Ge, Zhang
2016-01-01
Highlights: • A decision-making model of generation technology investment is proposed. • The irreversible investment concept and real option theory is introduced. • Practical data was used to prove the validity of the model. • Impact of electricity and fuel price fluctuation on investment was analyzed. - Abstract: The introduction of market competition and the increased uncertainty factors makes the generators have to decide not only on whether to invest generation capacity or not but also on what kind of generation technology to choose. In this paper, a decision-making model of generation technology investment is proposed. The irreversible investment concept and real option theory is introduced as the fundamental of the model. In order to explain the decision-making process of generator’s investment, the decision-making optimization model was built considering two generation technologies, i.e., the heat-only system and the combined heat and power generation. Also, we discussed the theory deducing process, which explained how to eliminate the overrated economic potential caused by risk hazard, based on economic evaluation of both generation technologies. Finally, practical data from electricity market of Inner Mongolia was used to prove the validity of the model and the impact of uncertainties of electricity and fuel price fluctuation on investment was analyzed according to the simulated results.
Analytic models of spectral responses of fiber-grating-based interferometers on FMC theory.
Zeng, Xiangkai; Wei, Lai; Pan, Yingjun; Liu, Shengping; Shi, Xiaohui
2012-02-13
In this paper the analytic models (AMs) of the spectral responses of fiber-grating-based interferometers are derived from the Fourier mode coupling (FMC) theory proposed recently. The interferometers include Fabry-Perot cavity, Mach-Zehnder and Michelson interferometers, which are constructed by uniform fiber Bragg gratings and long-period fiber gratings, and also by Gaussian-apodized ones. The calculated spectra based on the analytic models are achieved, and compared with the measured cases and those on the transfer matrix (TM) method. The calculations and comparisons have confirmed that the AM-based spectrum is in excellent agreement with the TM-based one and the measured case, of which the efficiency is improved up to ~2990 times that of the TM method for non-uniform-grating-based in-fiber interferometers.
Energy Technology Data Exchange (ETDEWEB)
Ridolfi, E.; Napolitano, F., E-mail: francesco.napolitano@uniroma1.it [Sapienza Università di Roma, Dipartimento di Ingegneria Civile, Edile e Ambientale (Italy); Alfonso, L. [Hydroinformatics Chair Group, UNESCO-IHE, Delft (Netherlands); Di Baldassarre, G. [Department of Earth Sciences, Program for Air, Water and Landscape Sciences, Uppsala University (Sweden)
2016-06-08
The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers’ cross-sectional spacing.
International Nuclear Information System (INIS)
Ridolfi, E.; Napolitano, F.; Alfonso, L.; Di Baldassarre, G.
2016-01-01
The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers’ cross-sectional spacing.
Directory of Open Access Journals (Sweden)
Zhifeng Zhong
2017-01-01
Full Text Available Owing to the environment, temperature, and so forth, photovoltaic power generation volume is always fluctuating and subsequently impacts power grid planning and operation seriously. Therefore, it is of great importance to make accurate prediction of the power generation of photovoltaic (PV system in advance. In order to improve the prediction accuracy, in this paper, a novel particle swarm optimization algorithm based multivariable grey theory model is proposed for short-term photovoltaic power generation volume forecasting. It is highlighted that, by integrating particle swarm optimization algorithm, the prediction accuracy of grey theory model is expected to be highly improved. In addition, large amounts of real data from two separate power stations in China are being employed for model verification. The experimental results indicate that, compared with the conventional grey model, the mean relative error in the proposed model has been reduced from 7.14% to 3.53%. The real practice demonstrates that the proposed optimization model outperforms the conventional grey model from both theoretical and practical perspectives.
Capacity Prediction Model Based on Limited Priority Gap-Acceptance Theory at Multilane Roundabouts
Directory of Open Access Journals (Sweden)
Zhaowei Qu
2014-01-01
Full Text Available Capacity is an important design parameter for roundabouts, and it is the premise of computing their delay and queue. Roundabout capacity has been studied for decades, and empirical regression model and gap-acceptance model are the two main methods to predict it. Based on gap-acceptance theory, by considering the effect of limited priority, especially the relationship between limited priority factor and critical gap, a modified model was built to predict the roundabout capacity. We then compare the results between Raff’s method and maximum likelihood estimation (MLE method, and the MLE method was used to predict the critical gaps. Finally, the predicted capacities from different models were compared, with the observed capacity by field surveys, which verifies the performance of the proposed model.
Real time polymer nanocomposites-based physical nanosensors: theory and modeling
Bellucci, Stefano; Shunin, Yuri; Gopeyenko, Victor; Lobanova-Shunina, Tamara; Burlutskaya, Nataly; Zhukovskii, Yuri
2017-09-01
Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences.
Ueckert, Sebastian; Plan, Elodie L; Ito, Kaori; Karlsson, Mats O; Corrigan, Brian; Hooker, Andrew C
2014-08-01
This work investigates improved utilization of ADAS-cog data (the primary outcome in Alzheimer's disease (AD) trials of mild and moderate AD) by combining pharmacometric modeling and item response theory (IRT). A baseline IRT model characterizing the ADAS-cog was built based on data from 2,744 individuals. Pharmacometric methods were used to extend the baseline IRT model to describe longitudinal ADAS-cog scores from an 18-month clinical study with 322 patients. Sensitivity of the ADAS-cog items in different patient populations as well as the power to detect a drug effect in relation to total score based methods were assessed with the IRT based model. IRT analysis was able to describe both total and item level baseline ADAS-cog data. Longitudinal data were also well described. Differences in the information content of the item level components could be quantitatively characterized and ranked for mild cognitively impairment and mild AD populations. Based on clinical trial simulations with a theoretical drug effect, the IRT method demonstrated a significantly higher power to detect drug effect compared to the traditional method of analysis. A combined framework of IRT and pharmacometric modeling permits a more effective and precise analysis than total score based methods and therefore increases the value of ADAS-cog data.
Homayounfar, Mehran; Zomorodian, Mehdi; Martinez, Christopher J; Lai, Sai Hin
2015-01-01
So far many optimization models based on Nash Bargaining Theory associated with reservoir operation have been developed. Most of them have aimed to provide practical and efficient solutions for water allocation in order to alleviate conflicts among water users. These models can be discussed from two viewpoints: (i) having a discrete nature; and (ii) working on an annual basis. Although discrete dynamic game models provide appropriate reservoir operator policies, their discretization of variables increases the run time and causes dimensionality problems. In this study, two monthly based non-discrete optimization models based on the Nash Bargaining Solution are developed for a reservoir system. In the first model, based on constrained state formulation, the first and second moments (mean and variance) of the state variable (water level in the reservoir) is calculated. Using moment equations as the constraint, the long-term utility of the reservoir manager and water users are optimized. The second model is a dynamic approach structured based on continuous state Markov decision models. The corresponding solution based on the collocation method is structured for a reservoir system. In this model, the reward function is defined based on the Nash Bargaining Solution. Indeed, it is used to yield equilibrium in every proper sub-game, thereby satisfying the Markov perfect equilibrium. Both approaches are applicable for water allocation in arid and semi-arid regions. A case study was carried out at the Zayandeh-Rud river basin located in central Iran to identify the effectiveness of the presented methods. The results are compared with the results of an annual form of dynamic game, a classical stochastic dynamic programming model (e.g. Bayesian Stochastic Dynamic Programming model, BSDP), and a discrete stochastic dynamic game model (PSDNG). By comparing the results of alternative methods, it is shown that both models are capable of tackling conflict issues in water allocation
Directory of Open Access Journals (Sweden)
Mehran Homayounfar
Full Text Available So far many optimization models based on Nash Bargaining Theory associated with reservoir operation have been developed. Most of them have aimed to provide practical and efficient solutions for water allocation in order to alleviate conflicts among water users. These models can be discussed from two viewpoints: (i having a discrete nature; and (ii working on an annual basis. Although discrete dynamic game models provide appropriate reservoir operator policies, their discretization of variables increases the run time and causes dimensionality problems. In this study, two monthly based non-discrete optimization models based on the Nash Bargaining Solution are developed for a reservoir system. In the first model, based on constrained state formulation, the first and second moments (mean and variance of the state variable (water level in the reservoir is calculated. Using moment equations as the constraint, the long-term utility of the reservoir manager and water users are optimized. The second model is a dynamic approach structured based on continuous state Markov decision models. The corresponding solution based on the collocation method is structured for a reservoir system. In this model, the reward function is defined based on the Nash Bargaining Solution. Indeed, it is used to yield equilibrium in every proper sub-game, thereby satisfying the Markov perfect equilibrium. Both approaches are applicable for water allocation in arid and semi-arid regions. A case study was carried out at the Zayandeh-Rud river basin located in central Iran to identify the effectiveness of the presented methods. The results are compared with the results of an annual form of dynamic game, a classical stochastic dynamic programming model (e.g. Bayesian Stochastic Dynamic Programming model, BSDP, and a discrete stochastic dynamic game model (PSDNG. By comparing the results of alternative methods, it is shown that both models are capable of tackling conflict issues in
Prest, M
1988-01-01
In recent years the interplay between model theory and other branches of mathematics has led to many deep and intriguing results. In this, the first book on the topic, the theme is the interplay between model theory and the theory of modules. The book is intended to be a self-contained introduction to the subject and introduces the requisite model theory and module theory as it is needed. Dr Prest develops the basic ideas concerning what can be said about modules using the information which may be expressed in a first-order language. Later chapters discuss stability-theoretic aspects of module
Consensual decision-making model based on game theory for LNG processes
International Nuclear Information System (INIS)
Castillo, Luis; Dorao, Carlos A.
2012-01-01
Highlights: ► A Decision Making (DM) approach for LNG projects based on game theory is presented. ► DM framework was tested with two different cases, using analytical models and a simple LNG process. ► The problems were solved by using a Genetic Algorithm (GA) binary coding and Nash-GA. ► Integrated models from the design and optimization of the process could result in more realistic outcome. ► The major challenge in such a framework is related to the uncertainties in the market models. - Abstract: Decision-Making (DM) in LNG projects is a quite complex process due to the number of actors, approval phases, large investments and capital return in the long time. Furthermore, due to the very high investment of a LNG project, a detailed and efficient DM process is required in order to minimize risks. In this work a Decision-Making (DM) approach for LNG projects is presented. The approach is based on a consensus algorithm to address the consensus output over a common value using cost functions within a framework based on game theory. The DM framework was tested with two different cases. The first case was used for evaluating the performance of the framework with analytical models, while the second case corresponds to a simple LNG process. The problems were solved by using a Genetic Algorithm (GA) binary coding and Nash-GA. The results of the DM framework in the LNG project indicate that considering an integrated DM model and including the markets role from the design and optimization of the process more realistic outcome could be obtained. However, the major challenge in such a framework is related to the uncertainties in the market models.
Computational Model-Based Design of Leadership Support Based on Situational Leadership Theory
Bosse, T.; Duell, R.; Memon, Z.A.; Treur, J.; van der Wal, C.N.
2017-01-01
This paper introduces the design of an agent-based leadership support system exploiting a computational model for development of individuals or groups. It is to be used, for example, as a basis for systems to support a group leader in the development of individual group members or a group as a
Energy Technology Data Exchange (ETDEWEB)
Johnson, J. D. (Prostat, Mesa, AZ); Oberkampf, William Louis; Helton, Jon Craig (Arizona State University, Tempe, AZ); Storlie, Curtis B. (North Carolina State University, Raleigh, NC)
2006-10-01
Evidence theory provides an alternative to probability theory for the representation of epistemic uncertainty in model predictions that derives from epistemic uncertainty in model inputs, where the descriptor epistemic is used to indicate uncertainty that derives from a lack of knowledge with respect to the appropriate values to use for various inputs to the model. The potential benefit, and hence appeal, of evidence theory is that it allows a less restrictive specification of uncertainty than is possible within the axiomatic structure on which probability theory is based. Unfortunately, the propagation of an evidence theory representation for uncertainty through a model is more computationally demanding than the propagation of a probabilistic representation for uncertainty, with this difficulty constituting a serious obstacle to the use of evidence theory in the representation of uncertainty in predictions obtained from computationally intensive models. This presentation describes and illustrates a sampling-based computational strategy for the representation of epistemic uncertainty in model predictions with evidence theory. Preliminary trials indicate that the presented strategy can be used to propagate uncertainty representations based on evidence theory in analysis situations where naive sampling-based (i.e., unsophisticated Monte Carlo) procedures are impracticable due to computational cost.
A Heuristic Model for the Active Galactic Nucleus Based on the Planck Vacuum Theory
Directory of Open Access Journals (Sweden)
Daywitt W. C.
2009-07-01
Full Text Available The standard explanation for an active galactic nucleus (AGN is a "central engine" consisting of a hot accretion disk surrounding a supermassive black hole. Energy is generated by the gravitational infall of material which is heated to high temperatures in this dissipative accretion disk. What follows is an alternative model for the AGN based on the Planck vacuum (PV theory, where both the energy of the AGN and its variable luminosity are explained in terms of a variable photon flux emanating from the PV.
Modeling of a piezoelectric/piezomagnetic nano energy harvester based on two dimensional theory
Yan, Zhi
2018-01-01
This work presents a two dimensional theory for a piezoelectric/piezomagnetic bilayer nanoplate in coupled extensional and flexural vibrations with both flexoelectric and surface effects. The magneto-electro-elastic (MEE) coupling equations are derived from three-dimensional equations and Kirchhoff plate theory. Based on the developed theory, a piezoelectric/piezomagnetic nano energy harvester is proposed, which can generate electricity under time-harmonic applied magnetic field. The approximate solutions for the mechanical responses and voltage of the energy harvester are obtained using the weighted residual method. Results show that the properties of the proposed energy harvester are size-dependent due to the flexoelectric and surface effects, and such effects are more pronounced when the bilayer thickness is reduced to dozens of nanometers. It is also found that the magnetoelectric coupling coefficient and power density of the energy harvester are sensitive to the load resistance, the thickness fraction of the piezoelectric or the piezomagnetic layer and damping ratios. Moreover, results indicate that the flexoelectric effect could be made use to build a dielectric/piezomagnetic nano energy harvester. This work provides modeling techniques and numerical methods for investigating the size-dependent properties of MEE nanoplate-based energy harvester and could be helpful for designing nano energy harvesters using the principle of flexoelectricity.
The Model of Lake Operation in Water Transfer Projects Based on the Theory of Water- right
Bi-peng, Yan; Chao, Liu; Fang-ping, Tang
the lake operation is a very important content in Water Transfer Projects. The previous studies have not any related to water-right and water- price previous. In this paper, water right is divided into three parts, one is initialization waterright, another is by investment, and the third is government's water- right re-distribution. The water-right distribution model is also build. After analyzing the cost in water transfer project, a model and computation method for the capacity price as well as quantity price is proposed. The model of lake operation in water transfer projects base on the theory of water- right is also build. The simulation regulation for the lake was carried out by using historical data and Genetic Algorithms. Water supply and impoundment control line of the lake was proposed. The result can be used by south to north water transfer projects.
Mean-variance model for portfolio optimization with background risk based on uncertainty theory
Zhai, Jia; Bai, Manying
2018-04-01
The aim of this paper is to develop a mean-variance model for portfolio optimization considering the background risk, liquidity and transaction cost based on uncertainty theory. In portfolio selection problem, returns of securities and assets liquidity are assumed as uncertain variables because of incidents or lacking of historical data, which are common in economic and social environment. We provide crisp forms of the model and a hybrid intelligent algorithm to solve it. Under a mean-variance framework, we analyze the portfolio frontier characteristic considering independently additive background risk. In addition, we discuss some effects of background risk and liquidity constraint on the portfolio selection. Finally, we demonstrate the proposed models by numerical simulations.
Microscopic optical model potential based on Brueckner-Hartree-Fock theory
International Nuclear Information System (INIS)
Li Lulu; Zhao Enguang; Zhou Shangui; Li Zenghua; Zuo Wei; Bonaccorso, Angela; Lonbardo, Umberto
2010-01-01
The optical model is one of the most important models in the study of nuclear reactions. In the optical model, the elastic channel is considered to be dominant and the contributions of all other absorption channels are described by introducing an imaginary potential, Koning and Delaroche obtained empirically the so-called KDR optical potentials based on a best-fitting of massive experimental data on nucleon-nucleus scattering reactions. The volume part is found to be dominant in the real component of the OMP at low energies. Using the Bruckner-Hartree-Fock theory with Bonn B potential plus self consistent three body force, the nucleon-nucleus optical potential is studied in this thesis. In the Bruckner theory, the on-shell self energy, is corresponding to the depth of the volume part of the optical model potential (OMP) for nucleon-nucleus scattering. Using Bruckner-Hartree-Fock theory, the nucleon on-shell self energy is calculated based on Hughenoltz-Van Hove (HVH) theorem. The microscopic optical potentials thus obtained agree well with the volume part of the KDR potentials. Furthermore, the isospin splitting in the volume part of the OMP is also reproduced satisfactorily. The isospin effect in the volume part of the OMP is directly related to the isospin splitting of the effective mass of the nucleon. According to our results, the isospin splitting of neutron to proton effective mass is such that the neutron effective mass increases with isospin, whereas the proton effective mass decreases. The isovector potential U n (E) - U p (E) vanishes at energy E ≈ 200 MeV and then changes sign indicating a possible inversion in the effective mass isospin spitting. We also calculated from the Bruckner theory the imaginary part of the OMP, and the microscopic calculations predict that the isospin splitting exists also in the imaginary OMP whereas the empirical KDR potentials do not show this feature. The shape of the real component of the nucleon-nucleus OMP is
Using a Marginal Structural Model to Design a Theory-Based Mass Media Campaign.
Directory of Open Access Journals (Sweden)
Hiromu Nishiuchi
Full Text Available The essential first step in the development of mass media health campaigns is to identify specific beliefs of the target audience. The challenge is to prioritize suitable beliefs derived from behavioral theory. The purpose of this study was to identify suitable beliefs to target in a mass media campaign to change behavior using a new method to estimate the possible effect size of a small set of beliefs.Data were drawn from the 2010 Japanese Young Female Smoker Survey (n = 500, conducted by the Japanese Ministry of Health, Labor and Welfare. Survey measures included intention to quit smoking, psychological beliefs (attitude, norms, and perceived control based on the theory of planned behavior and socioeconomic status (age, education, household income, and marital status. To identify suitable candidate beliefs for a mass media health campaign, we estimated the possible effect size required to change the intention to quit smoking among the population of young Japanese women using the population attributable fraction from a marginal structural model.Thirteen percent of study participants intended to quit smoking. The marginal structural model estimated a population attributable fraction of 47 psychological beliefs (21 attitudes, 6 norms, and 19 perceived controls after controlling for socioeconomic status. The belief, "I could quit smoking if my husband or significant other recommended it" suggested a promising target for a mass media campaign (population attributable fraction = 0.12, 95% CI = 0.02-0.23. Messages targeting this belief could possibly improve intention rates by up to 12% among this population. The analysis also suggested the potential for regulatory action.This study proposed a method by which campaign planners can develop theory-based mass communication strategies to change health behaviors at the population level. This method might contribute to improving the quality of future mass health communication strategies and further
Using a Marginal Structural Model to Design a Theory-Based Mass Media Campaign.
Nishiuchi, Hiromu; Taguri, Masataka; Ishikawa, Yoshiki
2016-01-01
The essential first step in the development of mass media health campaigns is to identify specific beliefs of the target audience. The challenge is to prioritize suitable beliefs derived from behavioral theory. The purpose of this study was to identify suitable beliefs to target in a mass media campaign to change behavior using a new method to estimate the possible effect size of a small set of beliefs. Data were drawn from the 2010 Japanese Young Female Smoker Survey (n = 500), conducted by the Japanese Ministry of Health, Labor and Welfare. Survey measures included intention to quit smoking, psychological beliefs (attitude, norms, and perceived control) based on the theory of planned behavior and socioeconomic status (age, education, household income, and marital status). To identify suitable candidate beliefs for a mass media health campaign, we estimated the possible effect size required to change the intention to quit smoking among the population of young Japanese women using the population attributable fraction from a marginal structural model. Thirteen percent of study participants intended to quit smoking. The marginal structural model estimated a population attributable fraction of 47 psychological beliefs (21 attitudes, 6 norms, and 19 perceived controls) after controlling for socioeconomic status. The belief, "I could quit smoking if my husband or significant other recommended it" suggested a promising target for a mass media campaign (population attributable fraction = 0.12, 95% CI = 0.02-0.23). Messages targeting this belief could possibly improve intention rates by up to 12% among this population. The analysis also suggested the potential for regulatory action. This study proposed a method by which campaign planners can develop theory-based mass communication strategies to change health behaviors at the population level. This method might contribute to improving the quality of future mass health communication strategies and further research is needed.
Cyber situation awareness: modeling detection of cyber attacks with instance-based learning theory.
Dutt, Varun; Ahn, Young-Suk; Gonzalez, Cleotilde
2013-06-01
To determine the effects of an adversary's behavior on the defender's accurate and timely detection of network threats. Cyber attacks cause major work disruption. It is important to understand how a defender's behavior (experience and tolerance to threats), as well as adversarial behavior (attack strategy), might impact the detection of threats. In this article, we use cognitive modeling to make predictions regarding these factors. Different model types representing a defender, based on Instance-Based Learning Theory (IBLT), faced different adversarial behaviors. A defender's model was defined by experience of threats: threat-prone (90% threats and 10% nonthreats) and nonthreat-prone (10% threats and 90% nonthreats); and different tolerance levels to threats: risk-averse (model declares a cyber attack after perceiving one threat out of eight total) and risk-seeking (model declares a cyber attack after perceiving seven threats out of eight total). Adversarial behavior is simulated by considering different attack strategies: patient (threats occur late) and impatient (threats occur early). For an impatient strategy, risk-averse models with threat-prone experiences show improved detection compared with risk-seeking models with nonthreat-prone experiences; however, the same is not true for a patient strategy. Based upon model predictions, a defender's prior threat experiences and his or her tolerance to threats are likely to predict detection accuracy; but considering the nature of adversarial behavior is also important. Decision-support tools that consider the role of a defender's experience and tolerance to threats along with the nature of adversarial behavior are likely to improve a defender's overall threat detection.
Hartjen, Raymond H.
Albert Bandura of Stanford University has proposed four component processes to his theory of observational learning: a) attention, b) retention, c) motor reproduction, and d) reinforcement and motivation. This study represents one phase of an effort to relate modeling and observational learning theory to teacher training. The problem of this study…
A Practise-based Theory of SEIDET Smart Community Centre Model
CSIR Research Space (South Africa)
Phahlamohlaka, J
2015-11-01
Full Text Available , as it is designed using the international studies and theories. This paper presents the design of the smart community centre model. The design is described using Practice Theory concepts towards an empirical study that will be conducted using the General...
Simulating Serious Games: A Discrete-Time Computational Model Based on Cognitive Flow Theory
Westera, Wim
2018-01-01
This paper presents a computational model for simulating how people learn from serious games. While avoiding the combinatorial explosion of a games micro-states, the model offers a meso-level pathfinding approach, which is guided by cognitive flow theory and various concepts from learning sciences. It extends a basic, existing model by exposing…
Adjoint sensitivity analysis of dynamic reliability models based on Markov chains - I: Theory
International Nuclear Information System (INIS)
Cacuci, D. G.; Cacuci, D. G.; Ionescu-Bujor, M.
2008-01-01
The development of the adjoint sensitivity analysis procedure (ASAP) for generic dynamic reliability models based on Markov chains is presented, together with applications of this procedure to the analysis of several systems of increasing complexity. The general theory is presented in Part I of this work and is accompanied by a paradigm application to the dynamic reliability analysis of a simple binary component, namely a pump functioning on an 'up/down' cycle until it fails irreparably. This paradigm example admits a closed form analytical solution, which permits a clear illustration of the main characteristics of the ASAP for Markov chains. In particular, it is shown that the ASAP for Markov chains presents outstanding computational advantages over other procedures currently in use for sensitivity and uncertainty analysis of the dynamic reliability of large-scale systems. This conclusion is further underscored by the large-scale applications presented in Part II. (authors)
Adjoint sensitivity analysis of dynamic reliability models based on Markov chains - I: Theory
Energy Technology Data Exchange (ETDEWEB)
Cacuci, D. G. [Commiss Energy Atom, Direct Energy Nucl, Saclay, (France); Cacuci, D. G. [Univ Karlsruhe, Inst Nucl Technol and Reactor Safety, D-76021 Karlsruhe, (Germany); Ionescu-Bujor, M. [Forschungszentrum Karlsruhe, Fus Program, D-76021 Karlsruhe, (Germany)
2008-07-01
The development of the adjoint sensitivity analysis procedure (ASAP) for generic dynamic reliability models based on Markov chains is presented, together with applications of this procedure to the analysis of several systems of increasing complexity. The general theory is presented in Part I of this work and is accompanied by a paradigm application to the dynamic reliability analysis of a simple binary component, namely a pump functioning on an 'up/down' cycle until it fails irreparably. This paradigm example admits a closed form analytical solution, which permits a clear illustration of the main characteristics of the ASAP for Markov chains. In particular, it is shown that the ASAP for Markov chains presents outstanding computational advantages over other procedures currently in use for sensitivity and uncertainty analysis of the dynamic reliability of large-scale systems. This conclusion is further underscored by the large-scale applications presented in Part II. (authors)
Physically based multiscale-viscoplastic model for metals and steel alloys: Theory and computation
Abed, Farid H.
The main requirement of large deformation problems such as high-speed machining, impact, and various primarily metal forming, is to develop constitutive relations which are widely applicable and capable of accounting for complex paths of deformation. Achieving such desirable goals for material like metals and steel alloys involves a comprehensive study of their microstructures and experimental observations under different loading conditions. In general, metal structures display a strong rate- and temperature-dependence when deformed non-uniformly into the inelastic range. This effect has important implications for an increasing number of applications in structural and engineering mechanics. The mechanical behavior of these applications cannot be characterized by classical (rate-independent) continuum theories because they incorporate no 'material length scales'. It is therefore necessary to develop a rate-dependent (viscoplasticity) continuum theory bridging the gap between the classical continuum theories and the microstructure simulations. Physically based vicoplasticity models for different types of metals (body centered cubic, face centered cubic and hexagonal close-packed) and steel alloys are derived in this work for this purpose. We adopt a multi-scale, hierarchical thermodynamic consistent framework to construct the material constitutive relations for the rate-dependent behavior. The concept of thermal activation energy, dislocations interactions mechanisms and the role of dislocations dynamics in crystals are used in the derivation process taking into consideration the contribution of the plastic strain evolution of dislocation density to the flow stress of polycrystalline metals. Material length scales are implicitly introduced into the governing equations through material rate-dependency (viscosity). The proposed framework is implemented into the commercially well-known finite element software ABAQUS. The finite element simulations of material
Models based on multichannel R-matrix theory for evaluating light element reactions
International Nuclear Information System (INIS)
Dodder, D.C.; Hale, G.M.; Nisley, R.A.; Witte, K.; Young, P.G.
1975-01-01
Multichannel R-matrix theory has been used as a basis for models for analysis and evaluation of light nuclear systems. These models have the characteristic that data predictions can be made utilizing information derived from other reactions related to the one of primary interest. Several examples are given where such an approach is valid and appropriate. (auth.)
International Nuclear Information System (INIS)
Lee, Gyeong Geun; Lee, Yong Bok; Kim, Min Chul; Kwon, Junh Yun
2012-01-01
Neutron irradiation to reactor pressure vessel (RPV) steels causes a decrease in fracture toughness and an increase in yield strength while in service. It is generally accepted that the growth of point defect cluster (PDC) and copper rich precipitate (CRP) affects radiation hardening of RPV steels. A number of models have been proposed to account for the embrittlement of RPV steels. The rate theory based modeling mathematically described the evolution of radiation induced microstructures of ferritic steels under neutron irradiation. In this work, we compared the rate theory based modeling calculation with the surveillance test results of Korean Light Water Reactors (LWRs)
Chaipichit, Dudduan; Jantharajit, Nirat; Chookhampaeng, Sumalee
2015-01-01
The objectives of this research were to study issues around the management of science learning, problems that are encountered, and to develop a learning management model to address those problems. The development of that model and the findings of its study were based on Constructivist Theory and literature on reasoning strategies for enhancing…
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
Venturi Wet Gas Flow Modeling Based on Homogeneous and Separated Flow Theory
Directory of Open Access Journals (Sweden)
Xu Ying
2008-10-01
Full Text Available When Venturi meters are used in wet gas, the measured differential pressure is higher than it would be in gas phases flowing alone. This phenomenon is called over-reading. Eight famous over-reading correlations have been studied by many researchers under low- and high-pressure conditions, the conclusion is separated flow model and homogeneous flow model performing well both under high and low pressures. In this study, a new metering method is presented based on homogeneous and separated flow theory; the acceleration pressure drop and the friction pressure drop of Venturi under two-phase flow conditions are considered in new correlation, and its validity is verified through experiment. For low pressure, a new test program has been implemented in Tianjin UniversityÃ¢Â€Â™s low-pressure wet gas loop. For high pressure, the National Engineering Laboratory offered their reports on the web, so the coefficients of the new proposed correlation are fitted with all independent data both under high and low pressures. Finally, the applicability and errors of new correlation are analyzed.
Directory of Open Access Journals (Sweden)
Lina Ke
2013-01-01
Full Text Available With the rapid development of marine economy industry, the activities for exploring and exploiting the marine resources are increasing, and there are more and more marine construction projects, which contribute to the growing trend of eutrophication and frequent occurrence of red tide. Thus, seawater quality has become the topic which the people generally cared about. The seawater quality evaluation could be considered as an analysis process which combined the evaluation indexes with certainty and evaluation factors with uncertainty and its changes. This paper built a model for the assessment of seawater environmental quality based on the multiobjective variable fuzzy set theory (VFEM. The Qingdao marine dumping site in China is taken as an evaluation example. Through the quantitative research of water-quality data from 2004 to 2008, the model is more reliable than other traditional methods, in which uncertainty and ambiguity of the seawater quality evaluation are considered, and trade the stable results as the final results of seawater quality evaluation, which effectively solved the impact of the fuzzy boundary of evaluation standard and monitoring error, is more suitable for evaluation of a multi-index, multilevel, and nonlinear marine environment system and has been proved to be an effective tool for seawater quality evaluation.
Grey-Theory-Based Optimization Model of Emergency Logistics Considering Time Uncertainty.
Qiu, Bao-Jian; Zhang, Jiang-Hua; Qi, Yuan-Tao; Liu, Yang
2015-01-01
Natural disasters occur frequently in recent years, causing huge casualties and property losses. Nowadays, people pay more and more attention to the emergency logistics problems. This paper studies the emergency logistics problem with multi-center, multi-commodity, and single-affected-point. Considering that the path near the disaster point may be damaged, the information of the state of the paths is not complete, and the travel time is uncertainty, we establish the nonlinear programming model that objective function is the maximization of time-satisfaction degree. To overcome these drawbacks: the incomplete information and uncertain time, this paper firstly evaluates the multiple roads of transportation network based on grey theory and selects the reliable and optimal path. Then simplify the original model under the scenario that the vehicle only follows the optimal path from the emergency logistics center to the affected point, and use Lingo software to solve it. The numerical experiments are presented to show the feasibility and effectiveness of the proposed method.
Nissen, Poul
2011-01-01
In this paper, a model for assessment and intervention is presented. This model explains how to perform theory- and evidence- based as well as practice-based assessment and intervention. The assessment model applies a holistic approach to treatment planning, which includes recognition of the influence of community, school, peers, family and the…
Parallel double-plate capacitive proximity sensor modelling based on effective theory
International Nuclear Information System (INIS)
Li, Nan; Zhu, Haiye; Wang, Wenyu; Gong, Yu
2014-01-01
A semi-analytical model for a double-plate capacitive proximity sensor is presented according to the effective theory. Three physical models are established to derive the final equation of the sensor. Measured data are used to determine the coefficients. The final equation is verified by using measured data. The average relative error of the calculated and the measured sensor capacitance is less than 7.5%. The equation can be used to provide guidance to engineering design of the proximity sensors
A theory of longitudinally polarised piezocomposite rod based on Mindlin-Herrmann model
CSIR Research Space (South Africa)
Shatalov, M
2010-09-01
Full Text Available The conventional theory of the piezoelectric rod is based on an assumption that its lateral vibrations are negligible. In this case the rod, vibration could be described in terms of one-dimensional wave equation and a set of mechanical and electric...
Deep Modeling: Circuit Characterization Using Theory Based Models in a Data Driven Framework
Energy Technology Data Exchange (ETDEWEB)
Bolme, David S [ORNL; Mikkilineni, Aravind K [ORNL; Rose, Derek C [ORNL; Yoginath, Srikanth B [ORNL; Holleman, Jeremy [University of Tennessee, Knoxville (UTK); Judy, Mohsen [University of Tennessee, Knoxville (UTK), Department of Electrical Engineering and Computer Science
2017-01-01
Analog computational circuits have been demonstrated to provide substantial improvements in power and speed relative to digital circuits, especially for applications requiring extreme parallelism but only modest precision. Deep machine learning is one such area and stands to benefit greatly from analog and mixed-signal implementations. However, even at modest precisions, offsets and non-linearity can degrade system performance. Furthermore, in all but the simplest systems, it is impossible to directly measure the intermediate outputs of all sub-circuits. The result is that circuit designers are unable to accurately evaluate the non-idealities of computational circuits in-situ and are therefore unable to fully utilize measurement results to improve future designs. In this paper we present a technique to use deep learning frameworks to model physical systems. Recently developed libraries like TensorFlow make it possible to use back propagation to learn parameters in the context of modeling circuit behavior. Offsets and scaling errors can be discovered even for sub-circuits that are deeply embedded in a computational system and not directly observable. The learned parameters can be used to refine simulation methods or to identify appropriate compensation strategies. We demonstrate the framework using a mixed-signal convolution operator as an example circuit.
Directory of Open Access Journals (Sweden)
Wasaye Muhammad Abdul
2017-01-01
Full Text Available An algorithm for the Monte Carlo simulation of electron multiple elastic scattering based on the framework of SuperMC (Super Monte Carlo simulation program for nuclear and radiation process is presented. This paper describes efficient and accurate methods by which the multiple scattering angular deflections are sampled. The Goudsmit-Saunderson theory of multiple scattering has been used for sampling angular deflections. Differential cross-sections of electrons and positrons by neutral atoms have been calculated by using Dirac partial wave program ELSEPA. The Legendre coefficients are accurately computed by using the Gauss-Legendre integration method. Finally, a novel hybrid method for sampling angular distribution has been developed. The model uses efficient rejection sampling method for low energy electrons (500 mean free paths. For small path lengths, a simple, efficient and accurate analytical distribution function has been proposed. The later uses adjustable parameters determined from the fitting of Goudsmith-Saunderson angular distribution. A discussion of the sampling efficiency and accuracy of this newly developed algorithm is given. The efficiency of rejection sampling algorithm is at least 50 % for electron kinetic energies less than 500 keV and longer path lengths (>500 mean free paths. Monte Carlo Simulation results are then compared with measured angular distributions of Ross et al. The comparison shows that our results are in good agreement with experimental measurements.
International Nuclear Information System (INIS)
Liu, Yanfeng; Zhou, Xiaojun; Wang, Dengjia; Song, Cong; Liu, Jiaping
2015-01-01
Highlights: • Fractal theory is introduced into the prediction of VOC diffusion coefficient. • MSFC model of the diffusion coefficient is developed for porous building materials. • The MSFC model contains detailed pore structure parameters. • The accuracy of the MSFC model is verified by independent experiments. - Abstract: Most building materials are porous media, and the internal diffusion coefficients of such materials have an important influences on the emission characteristics of volatile organic compounds (VOCs). The pore structure of porous building materials has a significant impact on the diffusion coefficient. However, the complex structural characteristics bring great difficulties to the model development. The existing prediction models of the diffusion coefficient are flawed and need to be improved. Using scanning electron microscope (SEM) observations and mercury intrusion porosimetry (MIP) tests of typical porous building materials, this study developed a new diffusivity model: the multistage series-connection fractal capillary-bundle (MSFC) model. The model considers the variable-diameter capillaries formed by macropores connected in series as the main mass transfer paths, and the diameter distribution of the capillary bundles obeys a fractal power law in the cross section. In addition, the tortuosity of the macrocapillary segments with different diameters is obtained by the fractal theory. Mesopores serve as the connections between the macrocapillary segments rather than as the main mass transfer paths. The theoretical results obtained using the MSFC model yielded a highly accurate prediction of the diffusion coefficients and were in a good agreement with the VOC concentration measurements in the environmental test chamber.
Theory of agent-based market models with controlled levels of greed and anxiety
Energy Technology Data Exchange (ETDEWEB)
Papadopoulos, P; Coolen, A C C [Department of Mathematics, King' s College London, The Strand, London WC2R 2LS (United Kingdom)], E-mail: panagiotis.2.papadopoulos@kcl.ac.uk, E-mail: ton.coolen@kcl.ac.uk
2010-01-15
We use generating functional analysis to study minority-game-type market models with generalized strategy valuation updates that control the psychology of agents' actions. The agents' choice between trend-following and contrarian trading, and their vigor in each, depends on the overall state of the market. Even in 'fake history' models, the theory now involves an effective overall bid process (coupled to the effective agent process) which can exhibit profound remanence effects and new phase transitions. For some models the bid process can be solved directly, others require Maxwell-construction-type approximations.
Theory of agent-based market models with controlled levels of greed and anxiety
International Nuclear Information System (INIS)
Papadopoulos, P; Coolen, A C C
2010-01-01
We use generating functional analysis to study minority-game-type market models with generalized strategy valuation updates that control the psychology of agents' actions. The agents' choice between trend-following and contrarian trading, and their vigor in each, depends on the overall state of the market. Even in 'fake history' models, the theory now involves an effective overall bid process (coupled to the effective agent process) which can exhibit profound remanence effects and new phase transitions. For some models the bid process can be solved directly, others require Maxwell-construction-type approximations.
Calculation of generalized Lorenz-Mie theory based on the localized beam models
International Nuclear Information System (INIS)
Jia, Xiaowei; Shen, Jianqi; Yu, Haitao
2017-01-01
It has been proved that localized approximation (LA) is the most efficient way to evaluate the beam shape coefficients (BSCs) in generalized Lorenz-Mie theory (GLMT). The numerical calculation of relevant physical quantities is a challenge for its practical applications due to the limit of computer resources. The study presents an improved algorithm of the GLMT calculation based on the localized beam models. The BSCs and the angular functions are calculated by multiplying them with pre-factors so as to keep their values in a reasonable range. The algorithm is primarily developed for the original localized approximation (OLA) and is further extended to the modified localized approximation (MLA). Numerical results show that the algorithm is efficient, reliable and robust. - Highlights: • In this work, we introduce the proper pre-factors to the Bessel functions, BSCs and the angular functions. With this improvement, all the quantities involved in the numerical calculation are scaled into a reasonable range of values so that the algorithm can be used for computing the physical quantities of the GLMT. • The algorithm is not only an improvement in numerical technique, it also implies that the set of basic functions involved in the electromagnetic scattering (and sonic scattering) can be reasonably chosen. • The algorithms of the GLMT computations introduced in previous references suggested that the order of the n and m sums is interchanged. In this work, the sum of azimuth modes is performed for each partial wave. This offers the possibility to speed up the computation, since the sum of partial waves can be optimized according to the illumination conditions and the sum of azimuth modes can be truncated by selecting a criterion discussed in . • Numerical results show that the algorithm is efficient, reliable and robust, even in very exotic cases. The algorithm presented in this paper is based on the original localized approximation and it can also be used for the
Diogo, V.; Koomen, E.; Kuhlman, T.
2015-01-01
An economic theory-based land-use modelling framework is presented aiming to explain the causal link between economic decisions and resulting spatial patterns of agricultural land use. The framework assumes that farmers pursue utility maximisation in agricultural production systems, while
Extensions to a nonlinear finite-element axisymmetric shell model based on Reissner's shell theory
International Nuclear Information System (INIS)
Cook, W.A.
1981-01-01
Extensions to shell analysis not usually associated with shell theory are described in this paper. These extensions involve thick shells, nonlinear materials, a linear normal stress approximation, and a changing shell thickness. A finite element shell-of-revolution model has been developed to analyze nuclear material shipping containers under severe impact conditions. To establish the limits for this shell model, the basic assumptions used in its development were studied; these are listed in this paper. Several extensions were evident from the study of these limits: a thick shell, a plastic hinge, and a linear normal stress
Security-Based Mechanism for Proactive Routing Schema Using Game Theory Model
Directory of Open Access Journals (Sweden)
Hicham Amraoui
2016-01-01
Full Text Available Game theory may offer a useful mechanism to address many problems in mobile ad hoc networks (MANETs. One of the key concepts in the research field of such networks with Optimized Link State Routing Protocol (OLSR is the security problem. Relying on applying game theory to study this problem, we consider two strategies during this suggested model: cooperate and not-cooperate. However, in such networks, it is not easy to identify different actions of players. In this paper, we have essentially been inspired from recent advances provided in game theory to propose a new model for security in MANETs. Our proposal presents a powerful tool with a large number of players where interactions are played multiple times. Moreover, each node keeps a cooperation rate (CR record of other nodes to cope with the behaviors and mitigate aggregate effect of other malicious devices. Additionally, our suggested security mechanism does not only take into consideration security requirements, but also take into account system resources and network performances. The simulation results using Network Simulator 3 are presented to illustrate the effectiveness of the proposal.
Social impact theory based modeling for security analysis in the nuclear fuel cycle
Energy Technology Data Exchange (ETDEWEB)
Woo, Tae Ho [Systemix Global Co. Ltd., Seoul (Korea, Republic of)
2015-03-15
The nuclear fuel cycle is investigated for the perspective of the nuclear non-proliferation. The random number generation of the Monte-Carlo method is utilized for the analysis. Five cases are quantified by the random number generations. These values are summed by the described equations. The higher values are shown in 52{sup nd} and 73{sup rd} months. This way could be a useful obligation in the license of the plant construction. The security of the nuclear fuel cycle incorporated with nuclear power plants (NPPs) is investigated using social impact theory. The dynamic quantification of the theory shows the non-secured time for act of terrorism which is considered for the non-secured condition against the risk of theft in nuclear material. For a realistic consideration, the meta-theoretical framework for modeling is performed for situations where beliefs, attributes or behaviors of an individual are influenced by those of others.
Social impact theory based modeling for security analysis in the nuclear fuel cycle
International Nuclear Information System (INIS)
Woo, Tae Ho
2015-01-01
The nuclear fuel cycle is investigated for the perspective of the nuclear non-proliferation. The random number generation of the Monte-Carlo method is utilized for the analysis. Five cases are quantified by the random number generations. These values are summed by the described equations. The higher values are shown in 52 nd and 73 rd months. This way could be a useful obligation in the license of the plant construction. The security of the nuclear fuel cycle incorporated with nuclear power plants (NPPs) is investigated using social impact theory. The dynamic quantification of the theory shows the non-secured time for act of terrorism which is considered for the non-secured condition against the risk of theft in nuclear material. For a realistic consideration, the meta-theoretical framework for modeling is performed for situations where beliefs, attributes or behaviors of an individual are influenced by those of others.
Towards computer-based perception by modeling visual perception : A probalistic theory
Ciftcioglu, O.; Bittermann, M.; Sariyildiz, S.
2006-01-01
Studies on computer-based perception by vision modelling are described. The visual perception is mathematically modelled where the model receives and interprets visual data from the environment. The perception is defined in probabilistic terms so that it is in the same way quantified. Human visual
Vollant, A.; Balarac, G.; Corre, C.
2017-09-01
New procedures are explored for the development of models in the context of large eddy simulation (LES) of a passive scalar. They rely on the combination of the optimal estimator theory with machine-learning algorithms. The concept of optimal estimator allows to identify the most accurate set of parameters to be used when deriving a model. The model itself can then be defined by training an artificial neural network (ANN) on a database derived from the filtering of direct numerical simulation (DNS) results. This procedure leads to a subgrid scale model displaying good structural performance, which allows to perform LESs very close to the filtered DNS results. However, this first procedure does not control the functional performance so that the model can fail when the flow configuration differs from the training database. Another procedure is then proposed, where the model functional form is imposed and the ANN used only to define the model coefficients. The training step is a bi-objective optimisation in order to control both structural and functional performances. The model derived from this second procedure proves to be more robust. It also provides stable LESs for a turbulent plane jet flow configuration very far from the training database but over-estimates the mixing process in that case.
Directory of Open Access Journals (Sweden)
Ricardo Chrobak
1997-05-01
Full Text Available Practically all research studies concerning the teaching of Physics point out the fact that conventional instructional models fail to achieve their objectives. Many attempts have been done to change this situation, frequently with disappointing results. This work, which is the experimental stage in a research project of a greater scope, represents an effort to change to a model based on a cognitive learning theory, known as the Ausubel-Novak-Gowin theory, making use of the metacognitive tools that emerge from this theory. The results of this work indicate that the students react positively to the goals of meaningful learning, showing substantial understanding of Newtonian Mechanics. An important reduction in the study time required to pass the course has also been reported.
Mutual diffusion coefficient models for polymer-solvent systems based on the Chapman-Enskog theory
Directory of Open Access Journals (Sweden)
R. A. Reis
2004-12-01
Full Text Available There are numerous examples of the importance of small molecule migration in polymeric materials, such as in drying polymeric packing, controlled drug delivery, formation of films, and membrane separation, etc. The Chapman-Enskog kinetic theory of hard-sphere fluids with the Weeks-Chandler-Andersen effective hard-sphere diameter (Enskog-WCA has been the most fruitful in diffusion studies of simple fluids and mixtures. In this work, the ability of the Enskog-WCA model to describe the temperature and concentration dependence of the mutual diffusion coefficient, D, for a polystyrene-toluene system was evaluated. Using experimental diffusion data, two polymer model approaches and three mixing rules for the effective hard-sphere diameter were tested. Some procedures tested resulted in models that are capable of correlating the experimental data with the refereed system well for a solvent mass fraction greater than 0.3.
A model of the open magnetosphere. [with field configuration based on Chapman-Ferraro theory
Kan, J. R.; Akasofu, S.-I.
1974-01-01
The Chapman-Ferraro image method is extended to construct an idealized model of the open magnetosphere that responds to a change of the interplanetary field direction as well as to a change of the field magnitude or of the solar wind momentum flux. The magnetopause of the present model is an infinite plane surface having a normal field component distribution that is consistent with the merging theory. An upper limit on the inward displacement of the magnetopause following a southward turning of the interplanetary field is obtained. The results are in fair agreement with a single event reported by Aubry et al. (1971). The model determines the field configuration and the total magnetic flux connecting the magnetosphere to interplanetary space.
An optoelectric professional's training model based on Unity of Knowing and Doing theory
Qin, Shiqiao; Wu, Wei; Zheng, Jiaxing; Wang, Xingshu; Zhao, Yingwei
2017-08-01
The "Unity of Knowing and Doing" (UKD) theory is proposed by an ancient Chinese philosopher, Wang Shouren, in 1508, which explains how to unify knowledge and practice. Different from the Chinese traditional UKD theory, the international higher education usually treats knowledge and practice as independent, and puts more emphasis on knowledge. Oriented from the UKD theory, the College of Opto-electric Science and Engineering (COESE) at National University of Defense Technology (NUDT) explores a novel training model in cultivating opto-electric professionals from the aspects of classroom teaching, practice experiment, system experiment, design experiment, research experiment and innovation experiment (CPSDRI). This model aims at promoting the unity of knowledge and practice, takes how to improve the students' capability as the main concern and tries to enhance the progress from cognition to professional action competence. It contains two hierarchies: cognition (CPS) and action competence (DRI). In the cognition hierarchy, students will focus on learning and mastering the professional knowledge of optics, opto-electric technology, laser, computer, electronics and machine through classroom teaching, practice experiment and system experiment (CPS). Great attention will be paid to case teaching, which links knowledge with practice. In the action competence hierarchy, emphasis will be placed on promoting students' capability of using knowledge to solve practical problems through design experiment, research experiment and innovation experiment (DRI). In this model, knowledge is divided into different modules and capability is cultivated on different levels. It combines classroom teaching and experimental teaching in a synergetic way and unifies cognition and practice, which is a valuable reference to the opto-electric undergraduate professionals' cultivation.
Thøgersen-Ntoumani, Cecilie; Ntoumanis, Nikos
2009-01-01
This study used self-determination theory (Deci, E.L., & Ryan, R.M. (2000). The 'what' and 'why' of goal pursuits: Human needs and the self-determination of behavior. Psychological Inquiry, 11, 227-268.) to examine predictors of body image concerns and unhealthy weight control behaviours in a sample of 350 Greek adolescent girls. A process model was tested which proposed that perceptions of parental autonomy support and two life goals (health and image) would predict adolescents' degree of sa...
Holman, Gordon D.
1989-01-01
The primary purpose of the Theory and Modeling Group meeting was to identify scientists engaged or interested in theoretical work pertinent to the Max '91 program, and to encourage theorists to pursue modeling which is directly relevant to data which can be expected to result from the program. A list of participants and their institutions is presented. Two solar flare paradigms were discussed during the meeting -- the importance of magnetic reconnection in flares and the applicability of numerical simulation results to solar flare studies.
Liu, Yanfeng; Zhou, Xiaojun; Wang, Dengjia; Song, Cong; Liu, Jiaping
2015-12-15
Most building materials are porous media, and the internal diffusion coefficients of such materials have an important influences on the emission characteristics of volatile organic compounds (VOCs). The pore structure of porous building materials has a significant impact on the diffusion coefficient. However, the complex structural characteristics bring great difficulties to the model development. The existing prediction models of the diffusion coefficient are flawed and need to be improved. Using scanning electron microscope (SEM) observations and mercury intrusion porosimetry (MIP) tests of typical porous building materials, this study developed a new diffusivity model: the multistage series-connection fractal capillary-bundle (MSFC) model. The model considers the variable-diameter capillaries formed by macropores connected in series as the main mass transfer paths, and the diameter distribution of the capillary bundles obeys a fractal power law in the cross section. In addition, the tortuosity of the macrocapillary segments with different diameters is obtained by the fractal theory. Mesopores serve as the connections between the macrocapillary segments rather than as the main mass transfer paths. The theoretical results obtained using the MSFC model yielded a highly accurate prediction of the diffusion coefficients and were in a good agreement with the VOC concentration measurements in the environmental test chamber. Copyright © 2015 Elsevier B.V. All rights reserved.
3D phenomenological constitutive modeling of shape memory alloys based on microplane theory
International Nuclear Information System (INIS)
Mehrabi, R; Kadkhodaei, M
2013-01-01
This paper concerns 3D phenomenological modeling of shape memory alloys using microplane theory. In the proposed approach, transformation is assumed to be the only source of inelastic strain in 1D constitutive laws considered for any generic plane passing through a material point. 3D constitutive equations are derived by generalizing the 1D equations using a homogenization technique. In the developed model, inelastic strain is explicitly stated in terms of the martensite volume fraction. To compare this approach with incremental constitutive models, such an available model is applied in its 1D integral form to the microplane formulation, and it is shown that both the approaches produce similar results for different uniaxial loadings. A nonproportional loading is then studied, and the results are compared with those obtained from an available model in which the inelastic strain is divided into two separate portions for transformation and reorientation. A good agreement is seen between the results of the two approaches, indicating the capability of the proposed microplane formulation in predicting reorientation phenomena in shape memory alloys. The results of the model are compared with available experimental results for a nonproportional loading path, and a good agreement is seen between the findings. (paper)
A model based on Copula Theory for sustainable and social responsible investments
Directory of Open Access Journals (Sweden)
Amelia Bilbao-Terol
2016-01-01
Full Text Available In this paper, a model is proposed that allows us to obtain a portfolio made up of sustainable and socially responsible (SR investment funds. This portfolio tracks the one that investors might have chosen if they had not taken into account social, ethical and ecological (SEE issues in their investment decisions. Therefore, in the first stage, reference portfolio exclusively made up of conventional funds is obtained. For the construction of the conventional portfolio the Prospect Theory has been used: net profits as the financial objective and error function as the utility function. In the second stage, a portfolio consisting exclusively of SR-funds is built. To do so, the reference portfolio is used as an ideal point, with the objectives of the SR-investor being the relative wealth with respect to the reference portfolio and the SEE quality of the portfolio. The relative wealth will be manipulated by a downside-risk measure, the Conditional Value at Risk (CVaR, and the periodic values of the portfolio. The second objective is the SR Quality of the portfolio, taking into account the personal values of a particular investor. This is built using Fuzzy Set Theory tools. We are faced with a multi-objective problem which is solved by using Goal Programming methodology. The estimation of both conventional and SR markets has been carried out by a semi-parametric approach by using the Copula Theory for modeling the dependence structure of the assets’ returns. The approach has been applied to a set of 38 conventional and 12 ethical funds domiciled in Spain.
Agent-based game theory modeling for driverless vehicles at intersections.
2013-02-01
This report presents three research efforts that were published in various journals. The first research effort presents a reactive-driving agent based algorithm for modeling driver left turn gap acceptance behavior at signalized intersections. This m...
Thøgersen-Ntoumani, Cecilie; Ntoumanis, Nikos; Nikitaras, Nikitas
2010-06-01
This study used self-determination theory (Deci, E.L., & Ryan, R.M. (2000). The 'what' and 'why' of goal pursuits: Human needs and the self-determination of behavior. Psychological Inquiry, 11, 227-268.) to examine predictors of body image concerns and unhealthy weight control behaviours in a sample of 350 Greek adolescent girls. A process model was tested which proposed that perceptions of parental autonomy support and two life goals (health and image) would predict adolescents' degree of satisfaction of their basic psychological needs. In turn, psychological need satisfaction was hypothesised to negatively predict body image concerns (i.e. drive for thinness and body dissatisfaction) and, indirectly, unhealthy weight control behaviours. The predictions of the model were largely supported indicating that parental autonomy support and adaptive life goals can indirectly impact upon the extent to which female adolescents engage in unhealthy weight control behaviours via facilitating the latter's psychological need satisfaction.
The Decision to Emigrate: A Simulation Model Based on the Theory of Planned Behaviour
Willekens, F.J.; Grow, A.; Van Bavel, J.
2016-01-01
The theory of planned behaviour (TPB) is one of the most widely used theories of behaviour. It was developed by Ajzen as an extension of Fishbein’s theory of reasoned action (Fishbein and Ajzen, Predicting and changing behaviour. Psychology Press, New York, 2010). The theory states that intentions
Economic policy optimization based on both one stochastic model and the parametric control theory
Ashimov, Abdykappar; Borovskiy, Yuriy; Onalbekov, Mukhit
2016-06-01
A nonlinear dynamic stochastic general equilibrium model with financial frictions is developed to describe two interacting national economies in the environment of the rest of the world. Parameters of nonlinear model are estimated based on its log-linearization by the Bayesian approach. The nonlinear model is verified by retroprognosis, estimation of stability indicators of mappings specified by the model, and estimation the degree of coincidence for results of internal and external shocks' effects on macroeconomic indicators on the basis of the estimated nonlinear model and its log-linearization. On the base of the nonlinear model, the parametric control problems of economic growth and volatility of macroeconomic indicators of Kazakhstan are formulated and solved for two exchange rate regimes (free floating and managed floating exchange rates)
A quantitative quasispecies theory-based model of virus escape mutation under immune selection.
Woo, Hyung-June; Reifman, Jaques
2012-08-07
Viral infections involve a complex interplay of the immune response and escape mutation of the virus quasispecies inside a single host. Although fundamental aspects of such a balance of mutation and selection pressure have been established by the quasispecies theory decades ago, its implications have largely remained qualitative. Here, we present a quantitative approach to model the virus evolution under cytotoxic T-lymphocyte immune response. The virus quasispecies dynamics are explicitly represented by mutations in the combined sequence space of a set of epitopes within the viral genome. We stochastically simulated the growth of a viral population originating from a single wild-type founder virus and its recognition and clearance by the immune response, as well as the expansion of its genetic diversity. Applied to the immune escape of a simian immunodeficiency virus epitope, model predictions were quantitatively comparable to the experimental data. Within the model parameter space, we found two qualitatively different regimes of infectious disease pathogenesis, each representing alternative fates of the immune response: It can clear the infection in finite time or eventually be overwhelmed by viral growth and escape mutation. The latter regime exhibits the characteristic disease progression pattern of human immunodeficiency virus, while the former is bounded by maximum mutation rates that can be suppressed by the immune response. Our results demonstrate that, by explicitly representing epitope mutations and thus providing a genotype-phenotype map, the quasispecies theory can form the basis of a detailed sequence-specific model of real-world viral pathogens evolving under immune selection.
DEFF Research Database (Denmark)
Kaplan, Sigal; Gruber, Johannes; Reinthaler, Martin
2016-01-01
Light and heavy duty commercial vehicles are a cause of concern in urban areas because of their cumulative stress on the system in terms of air pollution, congestion, and noise. This cumulative stress is expected to increase with the expected growth in commercial vehicle movements. While electric...... fleets. The framework is based on the Theory of Planned Behaviour (TPB), and it is modelled with a structural equation model with latent variables. The model is estimated on the basis of 1443 responses from a large-scale survey in Austria, Denmark, and Germany. The results establish a linkage between...
Time Prediction Models for Echinococcosis Based on Gray System Theory and Epidemic Dynamics.
Zhang, Liping; Wang, Li; Zheng, Yanling; Wang, Kai; Zhang, Xueliang; Zheng, Yujian
2017-03-04
Echinococcosis, which can seriously harm human health and animal husbandry production, has become an endemic in the Xinjiang Uygur Autonomous Region of China. In order to explore an effective human Echinococcosis forecasting model in Xinjiang, three grey models, namely, the traditional grey GM(1,1) model, the Grey-Periodic Extensional Combinatorial Model (PECGM(1,1)), and the Modified Grey Model using Fourier Series (FGM(1,1)), in addition to a multiplicative seasonal ARIMA(1,0,1)(1,1,0)₄ model, are applied in this study for short-term predictions. The accuracy of the different grey models is also investigated. The simulation results show that the FGM(1,1) model has a higher performance ability, not only for model fitting, but also for forecasting. Furthermore, considering the stability and the modeling precision in the long run, a dynamic epidemic prediction model based on the transmission mechanism of Echinococcosis is also established for long-term predictions. Results demonstrate that the dynamic epidemic prediction model is capable of identifying the future tendency. The number of human Echinococcosis cases will increase steadily over the next 25 years, reaching a peak of about 1250 cases, before eventually witnessing a slow decline, until it finally ends.
Time Prediction Models for Echinococcosis Based on Gray System Theory and Epidemic Dynamics
Directory of Open Access Journals (Sweden)
Liping Zhang
2017-03-01
Full Text Available Echinococcosis, which can seriously harm human health and animal husbandry production, has become an endemic in the Xinjiang Uygur Autonomous Region of China. In order to explore an effective human Echinococcosis forecasting model in Xinjiang, three grey models, namely, the traditional grey GM(1,1 model, the Grey-Periodic Extensional Combinatorial Model (PECGM(1,1, and the Modified Grey Model using Fourier Series (FGM(1,1, in addition to a multiplicative seasonal ARIMA(1,0,1(1,1,04 model, are applied in this study for short-term predictions. The accuracy of the different grey models is also investigated. The simulation results show that the FGM(1,1 model has a higher performance ability, not only for model fitting, but also for forecasting. Furthermore, considering the stability and the modeling precision in the long run, a dynamic epidemic prediction model based on the transmission mechanism of Echinococcosis is also established for long-term predictions. Results demonstrate that the dynamic epidemic prediction model is capable of identifying the future tendency. The number of human Echinococcosis cases will increase steadily over the next 25 years, reaching a peak of about 1250 cases, before eventually witnessing a slow decline, until it finally ends.
Supermatrix models for M-theory based on osp(1 vertical bar 32, R)
International Nuclear Information System (INIS)
Bagnoud, Maxime; Carlevaro, Luca; Bilal, Adel
2002-01-01
Taking seriously the hypothesis that the full symmetry algebra of M-theory is osp(1 vertical bar 32, R), we derive the supersymmetry transformations for all fields that appear in 11- and 12-dimensional realizations and give the associated SUSY algebras. We study the background-independent osp(1 vertical bar 32, R) cubic matrix model action expressed in terms of representations of the Lorentz groups SO(10,2) and SO(10,1). We explore further the 11-dimensional case and compute an effective action for the BFSS-like degrees of freedom. We find the usual BFSS action with additional terms incorporating couplings to transverse 5-branes, as well as a mass-term and an infinite tower of higher-order interactions
Korayem, M. H.; Taheri, M.
2014-01-01
In this article, the modeling of various contact theories to be applied in the biomanipulation of different micro/nanoparticles based on the atomic force microscope has been studied, and the effect of adhesion force in different contact models on indentation depth and contact angle between tip and substrate has been explored for the target biological micro/nanoparticle. The contact models used in this research include the Hertz, JKR, DMT, BCP, COS, PT, and the SUN models. Also, the target particles comprise the biological micro/nanoparticles of DNA, yeast, platelet, and nanobacterium. Previous research works have investigated the contact models for the manipulation of non-biological gold micro/nanoparticles in the air environment. Since in a real biomanipulation situation, the biological micro/nanoparticles are displaced in biological environments; in this article, various contact theories for the biomanipulation of biological micro/nanoparticles in different biological environments have been modeled and compared for the first time. The results of modeling indicate that the use of Hertz contact model in analyzing the biomanipulation of biological nanoparticles is not appropriate, because it does not take the adhesion force into consideration and thus produces a significant error. Also, all the six contact models developed in this article show larger deformations for studied bionanoparticles in comparison to the gold nanoparticles, which can be justified with regards to the mechanical properties of gold.
The μ3 model of acids and bases: extending the Lewis theory to intermetallics.
Stacey, Timothy E; Fredrickson, Daniel C
2012-04-02
A central challenge in the design of new metallic materials is the elucidation of the chemical factors underlying the structures of intermetallic compounds. Analogies to molecular bonding phenomena, such as the Zintl concept, have proven very productive in approaching this goal. In this Article, we extend a foundational concept of molecular chemistry to intermetallics: the Lewis theory of acids and bases. The connection is developed through the method of moments, as applied to DFT-calibrated Hückel calculations. We begin by illustrating that the third and fourth moments (μ(3) and μ(4)) of the electronic density of states (DOS) distribution tune the properties of a pseudogap. μ(3) controls the balance of states above and below the DOS minimum, with μ(4) then determining the minimum's depth. In this way, μ(3) predicts an ideal occupancy for the DOS distribution. The μ(3)-ideal electron count is used to forge a link between the reactivity of transition metals toward intermetallic phase formation, and that of Lewis acids and bases toward adduct formation. This is accomplished through a moments-based definition of acidity which classifies systems that are electron-poor relative to the μ(3)-ideal as μ(3)-acidic, and those that are electron-rich as μ(3)-basic. The reaction of μ(3) acids and bases, whether in the formation of a Lewis acid/base adduct or an intermetallic phase, tends to neutralize the μ(3) acidity or basicity of the reactants. This μ(3)-neutralization is traced to the influence of electronegativity differences at heteroatomic contacts on the projected DOS curves of the atoms involved. The role of μ(3)-acid/base interactions in intermetallic phases is demonstrated through the examination of 23 binary phases forming between 3d metals, the stability range of the CsCl type, and structural trends within the Ti-Ni system.
Guzmán, H. A.; Lárraga, M. E.; Alvarez-Icaza, L.; Carvajal, J.
2018-02-01
In this paper, a reliable cellular automata model oriented to faithfully reproduce deceleration and acceleration according to realistic reactions of drivers, when vehicles with different deceleration capabilities are considered is presented. The model focuses on describing complex traffic phenomena by coding in its rules the basic mechanisms of drivers behavior, vehicles capabilities and kinetics, while preserving simplicity. In particular, vehiclés kinetics is based on uniform accelerated motion, rather than in impulsive accelerated motion as in most existing CA models. Thus, the proposed model calculates in an analytic way three safe preserving distances to determine the best action a follower vehicle can take under a worst case scenario. Besides, the prediction analysis guarantees that under the proper assumptions, collision between vehicles may not happen at any future time. Simulations results indicate that all interactions of heterogeneous vehicles (i.e., car-truck, truck-car, car-car and truck-truck) are properly reproduced by the model. In addition, the model overcomes one of the major limitations of CA models for traffic modeling: the inability to perform smooth approach to slower or stopped vehicles. Moreover, the model is also capable of reproducing most empirical findings including the backward speed of the downstream front of the traffic jam, and different congested traffic patterns induced by a system with open boundary conditions with an on-ramp. Like most CA models, integer values are used to make the model run faster, which makes the proposed model suitable for real time traffic simulation of large networks.
Bergner, Yoav; Droschler, Stefan; Kortemeyer, Gerd; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.
2012-01-01
We apply collaborative filtering (CF) to dichotomously scored student response data (right, wrong, or no interaction), finding optimal parameters for each student and item based on cross-validated prediction accuracy. The approach is naturally suited to comparing different models, both unidimensional and multidimensional in ability, including a…
Multi-channel conduction in redox-based resistive switch modelled using quantum point contact theory
Energy Technology Data Exchange (ETDEWEB)
Miranda, E., E-mail: enrique.miranda@uab.cat; Suñé, J. [Departament d' Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallés, Barcelona (Spain); Mehonic, A.; Kenyon, A. J. [Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)
2013-11-25
A simple analytic model for the electron transport through filamentary-type structures in Si-rich silica (SiO{sub x})-based resistive switches is proposed. The model is based on a mesoscopic description and is able to account for the linear and nonlinear components of conductance that arise from both fully and partially formed conductive channels spanning the dielectric film. Channels are represented by arrays of identical scatterers whose number and quantum transmission properties determine the current magnitude in the low and high resistance states. We show that the proposed model not only reproduces the experimental current-voltage (I-V) characteristics but also the normalized differential conductance (dln(I)/dln(V)-V) curves of devices under test.
A Cloud Theory-Based Trust Computing Model in Social Networks
Directory of Open Access Journals (Sweden)
Fengming Liu
2016-12-01
Full Text Available How to develop a trust management model and then to efficiently control and manage nodes is an important issue in the scope of social network security. In this paper, a trust management model based on a cloud model is proposed. The cloud model uses a specific computation operator to achieve the transformation from qualitative concepts to quantitative computation. Additionally, this can also be used to effectively express the fuzziness, randomness and the relationship between them of the subjective trust. The node trust is divided into reputation trust and transaction trust. In addition, evaluation methods are designed, respectively. Firstly, the two-dimension trust cloud evaluation model is designed based on node’s comprehensive and trading experience to determine the reputation trust. The expected value reflects the average trust status of nodes. Then, entropy and hyper-entropy are used to describe the uncertainty of trust. Secondly, the calculation methods of the proposed direct transaction trust and the recommendation transaction trust involve comprehensively computation of the transaction trust of each node. Then, the choosing strategies were designed for node to trade based on trust cloud. Finally, the results of a simulation experiment in P2P network file sharing on an experimental platform directly reflect the objectivity, accuracy and robustness of the proposed model, and could also effectively identify the malicious or unreliable service nodes in the system. In addition, this can be used to promote the service reliability of the nodes with high credibility, by which the stability of the whole network is improved.
From Theory to Practice: One Agency's Experience with Implementing an Evidence-Based Model.
Murray, Maureen; Culver, Tom; Farmer, Betsy; Jackson, Leslie Ann; Rixon, Brian
2014-07-01
As evidence-based practice is becoming integrated into children's mental health services as a means of improving outcomes for children and youth with severe behavioral and emotional problems, therapeutic foster care (TFC) which is a specialized treatment program for such youth, is one of few community-based programs considered to be evidence-based. "Together Facing the Challenge" (TFTC) which was developed as a component of a randomized trial of TFC has been identified as an evidence-based model. We describe the experiences reported by one of the agencies that participated in our study and how they have incorporated TFTC into their on-going practice. They highlight key implementation strategies, challenges faced, and lessons learned as they moved forward towards full implementation of TFTC throughout their agency.
The economics of natural gas infrastructure investments. Theory and model-based analysis for Europe
Energy Technology Data Exchange (ETDEWEB)
Lochner, Stefan
2012-07-01
Changing supply structures, security of supply threats and efforts to eliminate bottlenecks and increase competition in the European gas market potentially warrant infrastructure investments. However, which investments are actually efficient is unclear. From a theoretical perspective, concepts from other sectors regarding the estimation of congestion cost and efficient investment can be applied - with some extensions - to natural gas markets. Investigations in a simple analytical framework, thereby, show that congestion does not necessarily imply that investment is efficient, and that there are multiple interdependencies between investments in different infrastructure elements (pipeline grid, gas storage, import terminals for liquefied natural gas (LNG)) which need to be considered in an applied analysis. Such interdependencies strengthen the case for a model-based analysis. An optimization model minimizing costs can illustrate the first-best solution with respect to investments in natural gas infrastructure; gas market characteristics such as temperature-dependent stochasticity of demand or the lumpiness of investments can be included. Scenario analyses help to show the effects of changing the underlying model presumption. Hence, results are projections subject to data and model assumption - and not forecasts. However, as they depict the optimal, cost-minimizing outcome, results provide a guideline to policymakers and regulators regarding the desirable market outcome. A stochastic mixed-integer dispatch and investment model for the European natural gas infrastructure is developed as an optimization model taking the theoretical inter-dependencies into account. It is based on an extensive infrastructure database including long-distance transmission pipelines, LNG terminals and gas storage sites with a high level of spatial granularity. It is parameterized with assumptions on supply and demand developments as well as empirically derived infrastructure extension costs
Research on manufacturing service behavior modeling based on block chain theory
Zhao, Gang; Zhang, Guangli; Liu, Ming; Yu, Shuqin; Liu, Yali; Zhang, Xu
2018-04-01
According to the attribute characteristics of processing craft, the manufacturing service behavior is divided into service attribute, basic attribute, process attribute, resource attribute. The attribute information model of manufacturing service is established. The manufacturing service behavior information is successfully divided into public and private domain. Additionally, the block chain technology is introduced, and the information model of manufacturing service based on block chain principle is established, which solves the problem of sharing and secreting information of processing behavior, and ensures that data is not tampered with. Based on the key pairing verification relationship, the selective publishing mechanism for manufacturing information is established, achieving the traceability of product data, guarantying the quality of processing quality.
Understanding urban inequality: a model based on existing theories and an empirical illustration.
Musterd, S.; Burgers, J.
2002-01-01
In the debate on urban inequality, Sassen's theory on social polarization and Wilson's theory on spatial mismatch have received much attention. Where Sassen highlights the decline of the middle classes, Wilson focuses on the upgrading of urban labour markets. In this article we argue that both
Directory of Open Access Journals (Sweden)
D. Carrella-Payan
2016-10-01
Full Text Available The aim of this study is to deal with the simulation of intralaminar fatigue damage in unidirectional composite under multi-axial and variable amplitude loadings. The variable amplitude and multi-axial loading is accounted for by using the damage hysteresis operator based on Brokate method [6]. The proposed damage model for fatigue is based on stiffness degradation laws from Van Paepegem combined with the ‘damage’ cycle jump approach extended to deal with unidirectional carbon fibres. The parameter identification method is here presented and parameter sensitivities are discussed. The initial static damage of the material is accounted for by using the Ladevèze damage model and the permanent shear strain accumulation based on Van Paepegem’s formulation. This approach is implemented into commercial software (Siemens PLM. The validation case is run on a bending test coupon (with arbitrary stacking sequence and load level in order to minimise the risk of inter-laminar damages. This intra-laminar fatigue damage model combined efficient methods with a low number of tests to identify the parameters of the stiffness degradation law, this overall procedure for fatigue life prediction is demonstrated to be cost efficient at industrial level. This work concludes on the next challenges to be addressed (validation tests, multiple-loadings validation, failure criteria, inter-laminar damages….
Directory of Open Access Journals (Sweden)
S. Sofana Reka
2016-06-01
Full Text Available In this paper, demand response modeling scheme is proposed for residential consumers using game theory algorithm as Generalized Tit for Tat (GTFT Dominant Game based Energy Scheduler. The methodology is established as a work flow domain model between the utility and the user considering the smart grid framework. It exhibits an algorithm which schedules load usage by creating several possible tariffs for consumers such that demand is never raised. This can be done both individually and among multiple users of a community. The uniqueness behind the demand response proposed is that, the tariff is calculated for all hours and the load during the peak hours which can be rescheduled is shifted based on the Peak Average Ratio. To enable the vitality of the work simulation results of a general case of three domestic consumers are modeled extended to a comparative performance and evaluation with other algorithms and inference is analyzed.
Gifford, Wendy; Graham, Ian D; Ehrhart, Mark G; Davies, Barbara L; Aarons, Gregory A
2017-01-01
Leadership in health care is instrumental to creating a supportive organizational environment and positive staff attitudes for implementing evidence-based practices to improve patient care and outcomes. The purpose of this study is to demonstrate the alignment of the Ottawa Model of Implementation Leadership (O-MILe), a theoretical model for developing implementation leadership, with the Implementation Leadership Scale (ILS), an empirically validated tool for measuring implementation leadership. A secondary objective is to describe the methodological process for aligning concepts of a theoretical model with an independently established measurement tool for evaluating theory-based interventions. Modified template analysis was conducted to deductively map items of the ILS onto concepts of the O-MILe. An iterative process was used in which the model and scale developers (n=5) appraised the relevance, conceptual clarity, and fit of each ILS items with the O-MILe concepts through individual feedback and group discussions until consensus was reached. All 12 items of the ILS correspond to at least one O-MILe concept, demonstrating compatibility of the ILS as a measurement tool for the O-MILe theoretical constructs. The O-MILe provides a theoretical basis for developing implementation leadership, and the ILS is a compatible tool for measuring leadership based on the O-MILe. Used together, the O-MILe and ILS provide an evidence- and theory-based approach for developing and measuring leadership for implementing evidence-based practices in health care. Template analysis offers a convenient approach for determining the compatibility of independently developed evaluation tools to test theoretical models.
Gifford, Wendy; Graham, Ian D; Ehrhart, Mark G; Davies, Barbara L; Aarons, Gregory A
2017-01-01
Purpose Leadership in health care is instrumental to creating a supportive organizational environment and positive staff attitudes for implementing evidence-based practices to improve patient care and outcomes. The purpose of this study is to demonstrate the alignment of the Ottawa Model of Implementation Leadership (O-MILe), a theoretical model for developing implementation leadership, with the Implementation Leadership Scale (ILS), an empirically validated tool for measuring implementation leadership. A secondary objective is to describe the methodological process for aligning concepts of a theoretical model with an independently established measurement tool for evaluating theory-based interventions. Methods Modified template analysis was conducted to deductively map items of the ILS onto concepts of the O-MILe. An iterative process was used in which the model and scale developers (n=5) appraised the relevance, conceptual clarity, and fit of each ILS items with the O-MILe concepts through individual feedback and group discussions until consensus was reached. Results All 12 items of the ILS correspond to at least one O-MILe concept, demonstrating compatibility of the ILS as a measurement tool for the O-MILe theoretical constructs. Conclusion The O-MILe provides a theoretical basis for developing implementation leadership, and the ILS is a compatible tool for measuring leadership based on the O-MILe. Used together, the O-MILe and ILS provide an evidence- and theory-based approach for developing and measuring leadership for implementing evidence-based practices in health care. Template analysis offers a convenient approach for determining the compatibility of independently developed evaluation tools to test theoretical models. PMID:29355212
A systematic composite service design modeling method using graph-based theory.
Elhag, Arafat Abdulgader Mohammed; Mohamad, Radziah; Aziz, Muhammad Waqar; Zeshan, Furkh
2015-01-01
The composite service design modeling is an essential process of the service-oriented software development life cycle, where the candidate services, composite services, operations and their dependencies are required to be identified and specified before their design. However, a systematic service-oriented design modeling method for composite services is still in its infancy as most of the existing approaches provide the modeling of atomic services only. For these reasons, a new method (ComSDM) is proposed in this work for modeling the concept of service-oriented design to increase the reusability and decrease the complexity of system while keeping the service composition considerations in mind. Furthermore, the ComSDM method provides the mathematical representation of the components of service-oriented design using the graph-based theoryto facilitate the design quality measurement. To demonstrate that the ComSDM method is also suitable for composite service design modeling of distributed embedded real-time systems along with enterprise software development, it is implemented in the case study of a smart home. The results of the case study not only check the applicability of ComSDM, but can also be used to validate the complexity and reusability of ComSDM. This also guides the future research towards the design quality measurement such as using the ComSDM method to measure the quality of composite service design in service-oriented software system.
Nieto, J.
2016-03-01
The learning phenomena, their complexity, concepts, structure, suitable theories and models, have been extensively treated in the mathematical literature in the last century, and [4] contains a very good introduction to the literature describing the many approaches and lines of research developed about them. Two main schools have to be pointed out [5] in order to understand the two -not exclusive- kinds of existing models: the stimulus sampling models and the stochastic learning models. Also [6] should be mentioned as a survey where two methods of learning are pointed out, the cognitive and the social, and where the knowledge looks like a mathematical unknown. Finally, as the authors do, we refer to the works [9,10], where the concept of population thinking was introduced and which motivate the game theory rules as a tool (both included in [4] to develop their theory) and [7], where the ideas of developing a mathematical kinetic theory of perception and learning were proposed.
Energy Technology Data Exchange (ETDEWEB)
Dai, J.C. [College of Mechanical and Electrical Engineering, Central South University, Changsha (China); School of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan (China); Hu, Y.P.; Liu, D.S. [School of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan (China); Long, X. [Hara XEMC Windpower Co., Ltd., Xiangtan (China)
2011-03-15
The aerodynamic loads for MW scale horizontal-axis wind turbines are calculated and analyzed in the established coordinate systems which are used to describe the wind turbine. In this paper, the blade element momentum (BEM) theory is employed and some corrections, such as Prandtl and Buhl models, are carried out. Based on the B-L semi-empirical dynamic stall (DS) model, a new modified DS model for NACA63-4xx airfoil is adopted. Then, by combing BEM modified theory with DS model, a set of calculation method of aerodynamic loads for large scale wind turbines is proposed, in which some influence factors such as wind shear, tower, tower and blade vibration are considered. The research results show that the presented dynamic stall model is good enough for engineering purpose; the aerodynamic loads are influenced by many factors such as tower shadow, wind shear, dynamic stall, tower and blade vibration, etc, with different degree; the single blade endures periodical changing loads but the variations of the rotor shaft power caused by the total aerodynamic torque in edgewise direction are very small. The presented study approach of aerodynamic loads calculation and analysis is of the university, and helpful for thorough research of loads reduction on large scale wind turbines. (author)
International Nuclear Information System (INIS)
Kim, Man Cheol; Seong, Poong Hyun
2006-01-01
To develop operator behavior models such as IDAC, quantitative models for the cognitive activities of nuclear power plant (NPP) operators in abnormal situations are essential. Among them, only few quantitative models for the monitoring and detection have been developed. In this paper, we propose a computational model for the knowledge-driven monitoring, which is also known as model-driven monitoring, of NPP operators in abnormal situations, based on the information theory. The basic assumption of the proposed model is that the probability that an operator shifts his or her attention to an information source is proportional to the expected information from the information source. A small experiment performed to evaluate the feasibility of the proposed model shows that the predictions made by the proposed model have high correlations with the experimental results. Even though it has been argued that heuristics might play an important role on human reasoning, we believe that the proposed model can provide part of the mathematical basis for developing quantitative models for knowledge-driven monitoring of NPP operators when NPP operators are assumed to behave very logically
MACCIA, ELIZABETH S.; AND OTHERS
AN ANNOTATED BIBLIOGRAPHY OF 20 ITEMS AND A DISCUSSION OF ITS SIGNIFICANCE WAS PRESENTED TO DESCRIBE CURRENT UTILIZATION OF SUBJECT THEORIES IN THE CONSTRUCTION OF AN EDUCATIONAL THEORY. ALSO, A THEORY MODEL WAS USED TO DEMONSTRATE CONSTRUCTION OF A SCIENTIFIC EDUCATIONAL THEORY. THE THEORY MODEL INCORPORATED SET THEORY (S), INFORMATION THEORY…
Complexity-Based Modeling of Scientific Capital: An Outline of Mathematical Theory
Directory of Open Access Journals (Sweden)
Yurij L. Katchanov
2014-01-01
measuring and assessing the accumulated recognition and the specific scientific power. The concept of scientific capital developed by Bourdieu is used in international social science research to explain a set of scholarly properties and practices. Mathematical modeling is applied as a lens through which the scientific capital is addressed. The principal contribution of this paper is an axiomatic characterization of scientific capital in terms of natural axioms. The application of the axiomatic method to scientific capital reveals novel insights into problem still not covered by mathematical modeling. Proposed model embraces the interrelations between separate sociological variables, providing a unified sociological view of science. Suggested microvariational principle is based upon postulate, which affirms that (under suitable conditions the observed state of the agent in scientific field maximizes scientific capital. Its value can be roughly imagined as a volume of social differences. According to the considered macrovariational principle, the actual state of scientific field makes so-called energy functional (which is associated with the distribution of scientific capital minimal.
Wang, Chengwen; Quan, Long; Zhang, Shijie; Meng, Hongjun; Lan, Yuan
2017-03-01
Hydraulic servomechanism is the typical mechanical/hydraulic double-dynamics coupling system with the high stiffness control and mismatched uncertainties input problems, which hinder direct applications of many advanced control approaches in the hydraulic servo fields. In this paper, by introducing the singular value perturbation theory, the original double-dynamics coupling model of the hydraulic servomechanism was reduced to a integral chain system. So that, the popular ADRC (active disturbance rejection control) technology could be directly applied to the reduced system. In addition, the high stiffness control and mismatched uncertainties input problems are avoided. The validity of the simplified model is analyzed and proven theoretically. The standard linear ADRC algorithm is then developed based on the obtained reduced-order model. Extensive comparative co-simulations and experiments are carried out to illustrate the effectiveness of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
A Web-based modeling tool for the SEMAT Essence theory of software engineering
Directory of Open Access Journals (Sweden)
Daniel Graziotin
2013-09-01
Full Text Available As opposed to more mature subjects, software engineering lacks general theories that establish its foundations as a discipline. The Essence Theory of software engineering (Essence has been proposed by the Software Engineering Methods and Theory (SEMAT initiative. The goal of Essence is to develop a theoretically sound basis for software engineering practice and its wide adoption. However, Essence is far from reaching academic- and industry-wide adoption. The reasons for this include a struggle to foresee its utilization potential and a lack of tools for implementation. SEMAT Accelerator (SematAcc is a Web-positioning tool for a software engineering endeavor, which implements the SEMAT’s Essence kernel. SematAcc permits the use of Essence, thus helping to understand it. The tool enables the teaching, adoption, and research of Essence in controlled experiments and case studies.
Open innovation: A preliminary model from the Knowledge-based Theory
Directory of Open Access Journals (Sweden)
Rocío González-Sánchez
2011-04-01
Full Text Available Purpose: The open innovation paradigm is an alternative and/or complementary way to knowledge management processes in its various stages, questioning the basic assumptions where some of the technological innovation strategies and processes are based on. The new logic of innovation process exploits knowledge dissemination through new innovation communities, on the one hand, and, considers of strategic value the external access to intangible resources. Thus, this approach supposes an alternative view to the traditional close innovation, focused on the exclusive exploitation of value innovations. This paper aims to contribute to building an integrated model of key factors to success in open innovation processes. It is analyzed for the role that certain key knowledge management decisions have on the results of open innovation projects, to facilitate the change process and provide new capacity or skills to do so. Design/methodology/approach: Through the review of theoretical and empirical literature, we show the main variables related to the functioning of open innovation systems, and establish various propositions about the meaning and intensity of such relationships.Findings: The management of open innovation project improves through three external factors: technical leadership based on experience, the intensive use of ICT, which allows a multilateral communication, and the existence of intermediate agents or facilitators with a strong neutral attitude. The results also depend on internal factors: the link function, the search routines, the establishment of incentive systems to encourage proactivity and organizational culture.Originality/value: In the absence of full proposals to guide effective decision making on both the management of relationships between organizations, as well as factors inherent to each of them, this paper proposes an exploratory model that integrates the key success factors in open innovation processes.
Directory of Open Access Journals (Sweden)
Chi-Chung Tao
2017-02-01
Full Text Available This study proposes a modified decomposed theory of planned behaviour model (DTPB that integrates satisfaction and trust into the original DTPB model to explore what kind of factors affect the user intention towards distance-based electronic toll collection (ETC services. The proposed model is empirically tested by using data collected from a questionnaire survey with a computer assisted telephone interview system. Empirical analysis is carried out in three stages that combine confirmatory factor analysis, structural equation modelling (SEM, and Bayesian network: (1 examination of reliability and validity of the measurement model; (2 analysis of structural model; (3 prediction of the probability of user intention change based on rigorous framework of SEM. The results confirm that the satisfaction and trust have positive effects on the behaviour intention, also validating that five constructs have indirect effects on the behaviour intention through attitude and perceived behaviour control. Compatibility is the most important influence factor, followed by perceived usefulness, facilitating conditions, self-efficacy, and perceived ease of use. The findings of this study identify potential improvements for ETC operator, such as contributing to the society to enhance the company image and trust of enterprise with charity activities, and simultaneously upgrading the information platform of website, software, and Apps.
Theory of mind in the Mod game : An agent-based model of strategic reasoning
de Weerd, Hermanes; Verbrugge, Rineke; Verheij, Bart; Herzig, Andreas; Lorini, Emiliano
2014-01-01
When people engage in social interactions, they often rely on their theory of mind, their ability to reason about unobservable mental content of others such as beliefs, goals, and intentions. This ability allows them to both understand why others behave the way they do as well as predict future
International Nuclear Information System (INIS)
Foltin, M.; Lukac, P.; Morva, I.; Foltin, V.
2004-01-01
In the paper the statistical 'phase-space theory' extended for chemical reactions and for dissociative recombination of polyatomic ions is applied to the indirect and direct dissociative recombination of diatomic ions with electrons. Numerical calculations are made for molecular neon ion. The good agreement is obtained with experimental results (Authors)
Directory of Open Access Journals (Sweden)
Gifford W
2017-03-01
Full Text Available Wendy Gifford,1 Ian D Graham,2,3 Mark G Ehrhart,4 Barbara L Davies,5,6 Gregory A Aarons7 1School of Nursing, Faculty of Health Sciences, University of Ottawa, ON, Canada; 2Centre for Practice-Changing Research, Ottawa Hospital Research Institute, 3School of Epidemiology, Public Health and Preventive Medicine, Facility of Medicine, University of Ottawa, Ottawa, ON, Canada; 4Department of Psychology, San Diego State University, San Diego, CA, USA; 5Nursing Best Practice Research Center, University of Ottawa, Ottawa, ON, Canada; 6Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; 7Child and Adolescent Services Research Center, University of California, San Diego, CA, USA Purpose: Leadership in health care is instrumental to creating a supportive organizational environment and positive staff attitudes for implementing evidence-based practices to improve patient care and outcomes. The purpose of this study is to demonstrate the alignment of the Ottawa Model of Implementation Leadership (O-MILe, a theoretical model for developing implementation leadership, with the Implementation Leadership Scale (ILS, an empirically validated tool for measuring implementation leadership. A secondary objective is to describe the methodological process for aligning concepts of a theoretical model with an independently established measurement tool for evaluating theory-based interventions.Methods: Modified template analysis was conducted to deductively map items of the ILS onto concepts of the O-MILe. An iterative process was used in which the model and scale developers (n=5 appraised the relevance, conceptual clarity, and fit of each ILS items with the O-MILe concepts through individual feedback and group discussions until consensus was reached.Results: All 12 items of the ILS correspond to at least one O-MILe concept, demonstrating compatibility of the ILS as a measurement tool for the O-MILe theoretical constructs.Conclusion: The O
Aycinena, Ana Corina; Jennings, Kerri-Ann; Gaffney, Ann Ogden; Koch, Pamela A.; Contento, Isobel R.; Gonzalez, Monica; Guidon, Ela; Karmally, Wahida; Hershman, Dawn; Greenlee, Heather
2017-01-01
We developed a theory-based dietary change curriculum for Hispanic breast cancer survivors with the goal of testing the effects of the intervention on change in dietary intake of fruits/vegetables and fat in a randomized, clinical trial. Social cognitive theory and the transtheoretical model were used as theoretical frameworks to structure…
Tang, Jinjun; Zhang, Shen; Chen, Xinqiang; Liu, Fang; Zou, Yajie
2018-03-01
Understanding Origin-Destination distribution of taxi trips is very important for improving effects of transportation planning and enhancing quality of taxi services. This study proposes a new method based on Entropy-Maximizing theory to model OD distribution in Harbin city using large-scale taxi GPS trajectories. Firstly, a K-means clustering method is utilized to partition raw pick-up and drop-off location into different zones, and trips are assumed to start from and end at zone centers. A generalized cost function is further defined by considering travel distance, time and fee between each OD pair. GPS data collected from more than 1000 taxis at an interval of 30 s during one month are divided into two parts: data from first twenty days is treated as training dataset and last ten days is taken as testing dataset. The training dataset is used to calibrate model while testing dataset is used to validate model. Furthermore, three indicators, mean absolute error (MAE), root mean square error (RMSE) and mean percentage absolute error (MPAE), are applied to evaluate training and testing performance of Entropy-Maximizing model versus Gravity model. The results demonstrate Entropy-Maximizing model is superior to Gravity model. Findings of the study are used to validate the feasibility of OD distribution from taxi GPS data in urban system.
Causal compositional models in valuation-based systems with examples in specific theories
Czech Academy of Sciences Publication Activity Database
Jiroušek, Radim; Shenoy, P. P.
2016-01-01
Roč. 72, č. 1 (2016), s. 95-112 ISSN 0888-613X Grant - others:GA ČR(CZ) GA15-00215S Institutional support: RVO:67985556 Keywords : operator of composition * causality * belief function Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 2.845, year: 2016 http://library.utia.cas.cz/separaty/2017/MTR/jirousek-0481260.pdf
Liu, Hongjie; Li, Tianhao; Zhan, Sha; Pan, Meilan; Ma, Zhiguo; Li, Chenghua
2016-01-01
Aims. To establish a logistic regression (LR) prediction model for hepatotoxicity of Chinese herbal medicines (HMs) based on traditional Chinese medicine (TCM) theory and to provide a statistical basis for predicting hepatotoxicity of HMs. Methods. The correlations of hepatotoxic and nonhepatotoxic Chinese HMs with four properties, five flavors, and channel tropism were analyzed with chi-square test for two-way unordered categorical data. LR prediction model was established and the accuracy of the prediction by this model was evaluated. Results. The hepatotoxic and nonhepatotoxic Chinese HMs were related with four properties (p 0.05). There were totally 12 variables from four properties and five flavors for the LR. Four variables, warm and neutral of the four properties and pungent and salty of five flavors, were selected to establish the LR prediction model, with the cutoff value being 0.204. Conclusions. Warm and neutral of the four properties and pungent and salty of five flavors were the variables to affect the hepatotoxicity. Based on such results, the established LR prediction model had some predictive power for hepatotoxicity of Chinese HMs. PMID:27656240
Power Load Prediction Based on Fractal Theory
Jian-Kai, Liang; Cattani, Carlo; Wan-Qing, Song
2015-01-01
The basic theories of load forecasting on the power system are summarized. Fractal theory, which is a new algorithm applied to load forecasting, is introduced. Based on the fractal dimension and fractal interpolation function theories, the correlation algorithms are applied to the model of short-term load forecasting. According to the process of load forecasting, the steps of every process are designed, including load data preprocessing, similar day selecting, short-term load forecasting, and...
Model for fusion and cool compound nucleus formation based on the fragmentation theory
International Nuclear Information System (INIS)
Malhotra, N.; Aroumougame, R.; Saroha, D.R.; Gupta, R.K.
1986-01-01
Collective potential energy surfaces are calculated in both the adiabatic and sudden approximations by using the asymmetric two-center shell model in the Strutinsky method. It is shown that fusion of two colliding heavy ions occurs by their crossing over of the adiabatic interaction barrier. The adiabatic scattering potentials present two barriers, whereas no barrier is shown to occur in sudden scattering potentials. The first barrier is obtained just past the saddle shape but is too low, such that a deep inelastic process is expected. The other, inner, barrier is high enough to let the system fall into the fusion well, whose excitation energy then determines whether a cool compound nucleus is produced or the fusion-fission process occurs. For a given compound nucleus, the excitation energy is found to be small for only a few target-projectile combinations, which increase as their mass asymmetry increases. Such target-projectile combinations which refer to a cool compound nucleus can be identified by a simple calculation of the fragmentation potential based on the ground state binding energies with Coulomb and proximity effects calculated at a constant relative separation of the two nuclei. Our calculations are made for the composite systems with 102 < or =Z < or =114
Model for fusion and cool compound nucleus formation based on the fragmentation theory
International Nuclear Information System (INIS)
Malhotra, N.; Aroumougame, R.; Saroha, D.R.; Gupta, R.K.
1985-07-01
The collective potential energy surfaces are calculated in both the adiabatic and sudden approximations by using the asymmetric two centre shell model in Strutinsky method. It is shown that fusion of two colliding heavy ions occur by their crossing over of the adiabatic interaction barrier. The adiabatic scattering potentials present two barriers whereas no barrier is shown to occur in sudden scattering potentials. The first barrier is obtained just past the saddle shape but is too low, such that a deep inelastic process is expected. The other, inner, barrier is high enough to let the system fall into the fusion well, whose excitation energy then determine whether a cool compound nucleus is produced or the fusion-fission process occurs. For a given compound nucleus, the excitation energy is found to be small for only a few target-projectile combinations, which increase as their mass asymmetry increases. Such target-projectile combinations which refer to a cool compound nucleus, can be identified by a simple calculation of the fragmentation potential based on the ground state binding energies with Couloumb and proximity effects calculated at a constant relative separation of the two nuclei. Our calculations are made for the composite systems with 102<=Z<=114. (author)
6D F-theory models and elliptically fibered Calabi-Yau threefolds over semi-toric base surfaces
Energy Technology Data Exchange (ETDEWEB)
Martini, Gabriella; Taylor, Washington [Center for Theoretical Physics, Department of Physics, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
2015-06-10
We carry out a systematic study of a class of 6D F-theory models and associated Calabi-Yau threefolds that are constructed using base surfaces with a generalization of toric structure. In particular, we determine all smooth surfaces with a structure invariant under a single ℂ{sup ∗} action (sometimes called “T-varieties” in the mathematical literature) that can act as bases for an elliptic fibration with section of a Calabi-Yau threefold. We identify 162,404 distinct bases, which include as a subset the previously studied set of strictly toric bases. Calabi-Yau threefolds constructed in this fashion include examples with previously unknown Hodge numbers. There are also bases over which the generic elliptic fibration has a Mordell-Weil group of sections with nonzero rank, corresponding to non-Higgsable U(1) factors in the 6D supergravity model; this type of structure does not arise for generic elliptic fibrations in the purely toric context.
6D F-theory models and elliptically fibered Calabi-Yau threefolds over semi-toric base surfaces
International Nuclear Information System (INIS)
Martini, Gabriella; Taylor, Washington
2015-01-01
We carry out a systematic study of a class of 6D F-theory models and associated Calabi-Yau threefolds that are constructed using base surfaces with a generalization of toric structure. In particular, we determine all smooth surfaces with a structure invariant under a single ℂ ∗ action (sometimes called “T-varieties” in the mathematical literature) that can act as bases for an elliptic fibration with section of a Calabi-Yau threefold. We identify 162,404 distinct bases, which include as a subset the previously studied set of strictly toric bases. Calabi-Yau threefolds constructed in this fashion include examples with previously unknown Hodge numbers. There are also bases over which the generic elliptic fibration has a Mordell-Weil group of sections with nonzero rank, corresponding to non-Higgsable U(1) factors in the 6D supergravity model; this type of structure does not arise for generic elliptic fibrations in the purely toric context.
Nguyen, Huong Thi Thu; Kitaoka, Kazuyo; Sukigara, Masune; Thai, Anh Lan
2018-03-01
This study aimed to create a Vietnamese version of both the Maslach Burnout Inventory-General Survey (MBI-GS) and Areas of Worklife Scale (AWS) to assess the burnout state of Vietnamese clinical nurses and to develop a causal model of burnout of clinical nurses. We conducted a descriptive design using a cross-sectional survey. The questionnaire was hand divided directly by nursing departments to 500 clinical nurses in three hospitals. Vietnamese MBI-GS and AWS were then examined for reliability and validity. We used the revised exhaustion +1 burnout classification to access burnout state. We performed path analysis to develop a Vietnamese causal model based on the original model by Leiter and Maslach's theory. We found that both scales were reliable and valid for assessing burnout. Among nurse participants, the percentage of severe burnout was 0.7% and burnout was 15.8%, and 17.2% of nurses were exhausted. The best predictor of burnout was "on-duty work schedule" that clinical nurses have to work for 24 hours. In the causal model, we also found similarity and difference pathways in comparison with the original model. Vietnamese MBI-GS and AWS were applicable to research on occupational stress. Nearly one-fifth of Vietnamese clinical nurses were working in burnout state. The causal model suggested a range of factors resulting in burnout, and it is necessary to consider the specific solution to prevent burnout problem. Copyright © 2018. Published by Elsevier B.V.
Sung, Dia; You, Yeongmahn; Song, Ji Hoon
2008-01-01
The purpose of this research is to explore the possibility of viable learning organizations based on identifying viable organizational learning mechanisms. Two theoretical foundations, complex system theory and viable system theory, have been integrated to provide the rationale for building the sustainable organizational learning mechanism. The…
Crisis in Context Theory: An Ecological Model
Myer, Rick A.; Moore, Holly B.
2006-01-01
This article outlines a theory for understanding the impact of a crisis on individuals and organizations. Crisis in context theory (CCT) is grounded in an ecological model and based on literature in the field of crisis intervention and on personal experiences of the authors. A graphic representation denotes key components and premises of CCT,…
Noar, Seth M; Myrick, Jessica Gall; Zeitany, Alexandra; Kelley, Dannielle; Morales-Pico, Brenda; Thomas, Nancy E
2015-01-01
The lack of a theory-based understanding of indoor tanning is a major impediment to the development of effective messages to prevent or reduce this behavior. This study applied the Comprehensive Indoor Tanning Expectations (CITE) scale in an analysis of indoor tanning behavior among sorority women (total N = 775). Confirmatory factor analyses indicated that CITE positive and negative expectations were robust, multidimensional factors and that a hierarchical structure fit the data well. Social cognitive theory-based structural equation models demonstrated that appearance-oriented variables were significantly associated with outcome expectations. Outcome expectations were, in turn, significantly associated with temptations to tan, intention to tan indoors, and indoor tanning behavior. The implications of these findings for the development of messages to prevent and reduce indoor tanning behavior are discussed in two domains: (a) messages that attempt to change broader societal perceptions about tan skin, and (b) messages that focus more narrowly on indoor tanning-challenging positive expectations, enhancing negative expectations, and encouraging substitution of sunless tanning products.
Directory of Open Access Journals (Sweden)
Dongxiao Niu
2012-01-01
Full Text Available Because clean energy and traditional energy have different advantages and disadvantages, it is of great significance to evaluate comprehensive benefits for hybrid power systems. Based on thorough analysis of important characters on hybrid power systems, an index system including security, economic benefit, environmental benefit, and social benefit is established in this paper. Due to advantages of processing abundant uncertain and fuzzy information, vague set is used to determine the decision matrix. Convert vague decision matrix to real one by vague combination ruleand determine uncertain degrees of different indexes by grey incidence analysis, then the mass functions of different comment set in different indexes are obtained. Information can be fused in accordance with Dempster-Shafer (D-S combination rule and the evaluation result is got by vague set and D-S evidence theory. A simulation of hybrid power system including thermal power, wind power, and photovoltaic power in China is provided to demonstrate the effectiveness and potential of the proposed design scheme. It can be clearly seen that the uncertainties in decision making can be dramatically decreased compared with existing methods in the literature. The actual implementation results illustrate that the proposed index system and evaluation model based on vague set and D-S evidence theory are effective and practical to evaluate comprehensive benefit of hybrid power system.
Skinner, Ellen A.; Chi, Una
2012-01-01
Building on self-determination theory, this study presents a model of intrinsic motivation and engagement as "active ingredients" in garden-based education. The model was used to create reliable and valid measures of key constructs, and to guide the empirical exploration of motivational processes in garden-based learning. Teacher- and…
National Research Council Canada - National Science Library
Farrell, Philip S
2007-01-01
This paper explores operations that involve effects-based thinking (EBT) using Control Theory techniques in order to highlight the concept's fundamental characteristics in a simple and straightforward manner...
DEFF Research Database (Denmark)
Pierart Vásquez, Fabián Gonzalo
, abundant and clean. Nevertheless, this technology has important drawbacks: the low viscosity of the lubricant results in a low load carrying capacity and gas bearings also presents low damping properties, which often lead to a reduced stability range and make dangerous running close to, or across...... theoretical model for active gas bearings, with special attention to the modelling of the injection system. Secondly, experimentally validate the improved mathematical model in terms of static properties (journal equilibrium position and resulting aerodynamic forces) and dynamic properties (natural...
Lectures on algebraic model theory
Hart, Bradd
2001-01-01
In recent years, model theory has had remarkable success in solving important problems as well as in shedding new light on our understanding of them. The three lectures collected here present recent developments in three such areas: Anand Pillay on differential fields, Patrick Speissegger on o-minimality and Matthias Clasen and Matthew Valeriote on tame congruence theory.
Directory of Open Access Journals (Sweden)
Peyman Ghafari Ashtiani
2016-08-01
Full Text Available One of the most advantages of the internet and its expansion is probably due to its easy and low cost access to unlimited information and easy and fast information exchange. The accession of communication technology for marketing area and emergence of the Internet leads to creation and development of new marketing models such as viral marketing. In fact, unlike other marketing methods, the most powerful tool for selling products and ideas are not done by a marketer to a customer but from a customer to another one. The purpose of this research is to analyze the relationship between customers' loyalty and the acceptance of viral marketing based on the theory of technology acceptance model (TAM model among the civil engineers and architects who are the members of Engineering Council in Isfahan (ECI. The research method is descriptive–survey and it is applicable in target. The statistical population includes civil engineers and architects who are the members of Engineering Council in Isfahan including 14400 members. The sample size was determined 762 members based on Cochran sampling formula, the sample was selected as accessible. The data was collected by field method. Analyzing the data and recent research hypothesis, the data was extracted from the questionnaires. Then, all the data was analyzed by computer and SPSS and LISREL software. According to the results of the data, the loyalty of the civil engineers and architects members of ECI was associated with the acceptance and practical involvement of viral marketing.
Zhong, Xuemin; Liu, Hongqi; Mao, Xinyong; Li, Bin; He, Songping; Peng, Fangyu
2018-05-01
Large multi-axis propeller-measuring machines have two types of geometric error, position-independent geometric errors (PIGEs) and position-dependent geometric errors (PDGEs), which both have significant effects on the volumetric error of the measuring tool relative to the worktable. This paper focuses on modeling, identifying and compensating for the volumetric error of the measuring machine. A volumetric error model in the base coordinate system is established based on screw theory considering all the geometric errors. In order to fully identify all the geometric error parameters, a new method for systematic measurement and identification is proposed. All the PIGEs of adjacent axes and the six PDGEs of the linear axes are identified with a laser tracker using the proposed model. Finally, a volumetric error compensation strategy is presented and an inverse kinematic solution for compensation is proposed. The final measuring and compensation experiments have further verified the efficiency and effectiveness of the measuring and identification method, indicating that the method can be used in volumetric error compensation for large machine tools.
Model integration and a theory of models
Dolk, Daniel R.; Kottemann, Jeffrey E.
1993-01-01
Model integration extends the scope of model management to include the dimension of manipulation as well. This invariably leads to comparisons with database theory. Model integration is viewed from four perspectives: Organizational, definitional, procedural, and implementational. Strategic modeling is discussed as the organizational motivation for model integration. Schema and process integration are examined as the logical and manipulation counterparts of model integr...
A model of epigenetic evolution based on theory of open quantum systems.
Asano, Masanari; Basieva, Irina; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro
2013-12-01
We present a very general model of epigenetic evolution unifying (neo-)Darwinian and (neo-)Lamarckian viewpoints. The evolution is represented in the form of adaptive dynamics given by the quantum(-like) master equation. This equation describes development of the information state of epigenome under the pressure of an environment. We use the formalism of quantum mechanics in the purely operational framework. (Hence, our model has no direct relation to quantum physical processes inside a cell.) Thus our model is about probabilities for observations which can be done on epigenomes and it does not provide a detailed description of cellular processes. Usage of the operational approach provides a possibility to describe by one model all known types of cellular epigenetic inheritance.
Extensions to a nonlinear finite element axisymmetric shell model based on Reissner's shell theory
International Nuclear Information System (INIS)
Cook, W.A.
1981-01-01
A finite element shell-of-revolution model has been developed to analyze shipping containers under severe impact conditions. To establish the limits for this shell model, I studied the basic assumptions used in its development; these are listed in this paper. Several extensions were evident from the study of these limits: a thick shell, a plastic hinge, and a linear normal stress. (orig./HP)
Condensation pressures in small pores: An analytical model based on density functional theory
Energy Technology Data Exchange (ETDEWEB)
R. H. Nilson; S. K. Griffiths
1999-02-01
Adsorption and condensation are critical to many applications of porous materials including filtration, separation, and the storage of gases. Integral methods are used to derive an analytical expression describing fluid condensation pressures in slit pores bounded by parallel plane walls. To obtain this result, the governing equations of Density Functional Theory (DFT) are integrated across the pore width assuming that fluid densities within adsorbed layers are spatially uniform. The thickness, density, and energy of these layers are expressed as composite functions constructed from asymptotic limits applicable to small and large pores. By equating the total energy of the adsorbed layers to that of a liquid-full pore, the authors arrive at a closed-form expression for the condensation pressure in terms of the pore size, surface tension, and Lennard-Jones parameters of the adsorbent and adsorbate molecules. The resulting equation reduces to the Kelvin equation in the large-pore limit. It further reproduces the condensation pressures computed by means of the full DFT equations for all pore sizes in which phase transitions are abrupt. Finally, in the limit of extremely small pores, for which phase transitions may be smooth and continuous, this simple analytical expression provides a good approximation to the apparent condensation pressure indicated by the steepest portion of the adsorption isotherm computed via DFT.
Condensation pressures in small pores: An analytical model based on density functional theory
International Nuclear Information System (INIS)
Nilson, R.H.; Griffiths, S.K.
1999-01-01
Integral methods are used to derive an analytical expression describing fluid condensation pressures in slit pores bounded by parallel plane walls. To obtain this result, the governing equations of density functional theory (DFT) are integrated across the pore width assuming that fluid densities within adsorbed layers are spatially uniform. The thickness, density, and free energy of these layers are expressed as composite functions constructed from asymptotic limits applicable to small and large pores. By equating the total free energy of the adsorbed layers to that of a liquid-full pore, we arrive at a closed-form expression for the condensation pressure in terms of the pore size, surface tension, and Lennard-Jones parameters of the adsorbent and adsorbate molecules. The resulting equation reduces to the Kelvin equation in the large-pore limit. It further reproduces the condensation pressures computed by means of the full DFT equations for all pore sizes in which phase transitions are abrupt. Finally, in the limit of extremely small pores, for which phase transitions may be smooth and continuous, this simple analytical expression provides a good approximation to the apparent condensation pressure indicated by the steepest portion of the adsorption isotherm computed via DFT. copyright 1999 American Institute of Physics
Theory-based model for the pedestal, edge stability and ELMs in tokamaks
International Nuclear Information System (INIS)
Pankin, A.Y.; Bateman, G.; Brennan, D.P.; Schnack, D.D.; Snyder, P.B.; Voitsekhovitch, I.; Kritz, A.H.; Janeschitz, G.; Kruger, S.; Onjun, T.; Pacher, G.W.; Pacher, H.D.
2006-01-01
An improved model for triggering edge localized mode (ELM) crashes is developed for use within integrated modelling simulations of the pedestal and ELM cycles at the edge of H-mode tokamak plasmas. The new model is developed by using the BALOO, DCON and ELITE ideal MHD stability codes to derive parametric expressions for the ELM triggering threshold. The whole toroidal mode number spectrum is studied with these codes. The DCON code applies to low mode numbers, while the BALOO code applies to only high mode numbers and the ELITE code applies to intermediate and high mode numbers. The variables used in the parametric stability expressions are the normalized pressure gradient and the parallel current density, which drive ballooning and peeling modes. Two equilibria motivated by DIII-D geometry with different plasma triangularities are studied. It is found that the stable region in the high triangularity discharge covers a much larger region of parameter space than the corresponding stability region in the low triangularity discharge. The new ELM trigger model is used together with a previously developed model for pedestal formation and ELM crashes in the ASTRA integrated modelling code to follow the time evolution of the temperature profiles during ELM cycles. The ELM frequencies obtained in the simulations of low and high triangularity discharges are observed to increase with increasing heating power. There is a transition from second stability to first ballooning mode stability as the heating power is increased in the high triangularity simulations. The results from the ideal MHD stability codes are compared with results from the resistive MHD stability code NIMROD
Directory of Open Access Journals (Sweden)
Jamal Bahiri Saleth
2016-01-01
Full Text Available Capital structure is a controversial issue in the field of corporate finance. There are several studies to find a way to determine the optimal capital structure to minimize the cost of capital and maximize the corporate value. In fact, capital structure is a combination of firms’ liabilities and capital to meet long term assets. This paper investigates the role of the hierarchical theory in explaining the capital structure of the firms based on enterprise life cycle model on selected firms listed on Tehran Stock Exchange (TSE using three methods of net equities, net liabilities and retained earnings. The study uses Park and Chen’s (2006 method [Park, Y., & Chen, K. H. (2006. The effect of accounting conservatism and life-cycle stages on firm valuation. Journal of Applied Business Research (JABR, 22(3, 75-92.] to categorize the life cycle of 81 randomly selected firms from TSE over the period 2007-2012. The results indicate that the hierarchical theory represents the growing firms better than the matured firms do. The results also show that firms were more willing to reduce their dividend per share for financing their projects.
Modeling and dynamical topology properties of VANET based on complex networks theory
Energy Technology Data Exchange (ETDEWEB)
Zhang, Hong; Li, Jie, E-mail: prof.li@foxmail.com [School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan, 430074 (China)
2015-01-15
Vehicular Ad hoc Network (VANET) is a special subset of multi-hop Mobile Ad hoc Networks in which vehicles can not only communicate with each other but also with the fixed equipments along the roads through wireless interfaces. Recently, it has been discovered that essential systems in real world share similar properties. When they are regarded as networks, among which the dynamic topology structure of VANET system is an important issue. Many real world networks are actually growing with preferential attachment like Internet, transportation system and telephone network. Those phenomena have brought great possibility in finding a strategy to calibrate and control the topology parameters which can help find VANET topology change regulation to relieve traffic jam, prevent traffic accident and improve traffic safety. VANET is a typical complex network which has its basic characteristics. In this paper, we focus on the macroscopic Vehicle-to-Infrastructure (V2I) and Vehicle-to-Vehicle (V2V) inter-vehicle communication network with complex network theory. In particular, this paper is the first one to propose a method analyzing the topological structure and performance of VANET and present the communications in VANET from a new perspective. Accordingly, we propose degree distribution, clustering coefficient and the short path length of complex network to implement our strategy by numerical example and simulation. All the results demonstrate that VANET shows small world network features and is characterized by a truncated scale-free degree distribution with power-law degree distribution. The average path length of the network is simulated numerically, which indicates that the network shows small-world property and is rarely affected by the randomness. What’s more, we carry out extensive simulations of information propagation and mathematically prove the power law property when γ > 2. The results of this study provide useful information for VANET optimization from a
Warped models in string theory
International Nuclear Information System (INIS)
Acharya, B.S.; Benini, F.; Valandro, R.
2006-12-01
Warped models, originating with the ideas of Randall and Sundrum, provide a fascinating extension of the standard model with interesting consequences for the LHC. We investigate in detail how string theory realises such models, with emphasis on fermion localisation and the computation of Yukawa couplings. We find, in contrast to the 5d models, that fermions can be localised anywhere in the extra dimension, and that there are new mechanisms to generate exponential hierarchies amongst the Yukawa couplings. We also suggest a way to distinguish these string theory models with data from the LHC. (author)
Braspenning, N.C.W.M.
2008-01-01
For manufacturers of high-tech multi-disciplinary systems such as semiconductor equipment, the effort required for integration and system testing is ever increasing, while customers demand a shorter time-to-market.This book describes how executable models can replace unavailable component
Influence of 3D printing on transport : a theory and experts judgment based conceptual model
Boon, Wouter; Van Wee, Bert
2017-01-01
Consumer 3D printing is on the rise and has the potential to significantly change the transport and logistics sector. Current literature on 3D printing and transport studies does not provide a systematic model of the impact of 3D printing on transport and related (policy relevant) areas, such as
Fiene, Richard J.; Woods, Lawrence
Two unanswered questions about child care are: (1) Does compliance with state child care regulations have a positive impact on children? and (2) Have predictors of program quality been identified? This paper explores a research study and related model that have had some success in answering these questions. Section I, a general introduction,…
Vacuum circuit breaker postarc current modelling based on the theory of Langmuir probes
Lanen, van E.P.A.; Smeets, R.; Popov, M.; Sluis, van der L.
2007-01-01
High-resolution measurements on the postarc current in vacuum circuit breakers (VCBs) reveal a period, immediately following current-zero, in which the voltage remains practically zero. The most widely used model for simulating the interaction between the postarc current with the electrical circuit
Seezink, Audrey; Poell, Rob F.; Kirschner, Paul A.
2009-01-01
Dutch prevocational secondary schools are reforming their educational programmes to make them more competence-based. This reform has substantial implications for the roles played by teachers. Yet, little empirical research has been conducted on teachers' processes of competence development in vocational settings. This study explores teachers'…
Prof. Dr. Paul A. Kirschner; Dr. Audrey Seezink; Prof. Dr. Rob F. Poell
2009-01-01
Dutch prevocational secondary schools are reforming their educational programmes to make them more competence-based. This reform has substantial implications for the roles played by teachers. Yet, little empirical research has been conducted on teachers' processes of competence development in
Modeling mechanical properties of a shear thickening fluid damper based on phase transition theory
Wei, Minghai; Lin, Kun; Guo, Qian
2018-03-01
Shear thickening fluids (STFs) are highly concentrated colloidal suspensions consisting of monodisperse nano-particles suspended in a carrying fluid, and have the capacity to display both flowable and rigid behaviors, when subjected to sudden stimuli. In that process, the external energy that acts on an STF can be dissipated quickly. The aim of this study is to present a dynamic model of a damper filled with STF that can be directly used in control engineering fields. To this end, shear stress during phase transition of the STF material is chosen as an internal variable. A non-convex function with bifurcation behavior is used to describe the phase transitioning of STF by determining the relationship between the behavioral characteristics of the microscopic phase and macroscopic damping force. This model is able to predict force-velocity and force-displacement relationships as functions of the loading frequency. Efficacy of the model is demonstrated via comparison with experimental results from previous studies. In addition, the results confirm the hypothesis regarding the occurrence of STF phase transitioning when subject to shear stress.
Kuiper, Rebecca M; Nederhoff, Tim; Klugkist, Irene
2015-05-01
In this paper, the performance of six types of techniques for comparisons of means is examined. These six emerge from the distinction between the method employed (hypothesis testing, model selection using information criteria, or Bayesian model selection) and the set of hypotheses that is investigated (a classical, exploration-based set of hypotheses containing equality constraints on the means, or a theory-based limited set of hypotheses with equality and/or order restrictions). A simulation study is conducted to examine the performance of these techniques. We demonstrate that, if one has specific, a priori specified hypotheses, confirmation (i.e., investigating theory-based hypotheses) has advantages over exploration (i.e., examining all possible equality-constrained hypotheses). Furthermore, examining reasonable order-restricted hypotheses has more power to detect the true effect/non-null hypothesis than evaluating only equality restrictions. Additionally, when investigating more than one theory-based hypothesis, model selection is preferred over hypothesis testing. Because of the first two results, we further examine the techniques that are able to evaluate order restrictions in a confirmatory fashion by examining their performance when the homogeneity of variance assumption is violated. Results show that the techniques are robust to heterogeneity when the sample sizes are equal. When the sample sizes are unequal, the performance is affected by heterogeneity. The size and direction of the deviations from the baseline, where there is no heterogeneity, depend on the effect size (of the means) and on the trend in the group variances with respect to the ordering of the group sizes. Importantly, the deviations are less pronounced when the group variances and sizes exhibit the same trend (e.g., are both increasing with group number). © 2014 The British Psychological Society.
Staircase Models from Affine Toda Field Theory
Dorey, P; Dorey, Patrick; Ravanini, Francesco
1993-01-01
We propose a class of purely elastic scattering theories generalising the staircase model of Al. B. Zamolodchikov, based on the affine Toda field theories for simply-laced Lie algebras g=A,D,E at suitable complex values of their coupling constants. Considering their Thermodynamic Bethe Ansatz equations, we give analytic arguments in support of a conjectured renormalisation group flow visiting the neighbourhood of each W_g minimal model in turn.
Directory of Open Access Journals (Sweden)
Huong Thi Thu Nguyen, RN, MPH
2018-03-01
Full Text Available Purpose: This study aimed to create a Vietnamese version of both the Maslach Burnout Inventory-General Survey (MBI-GS and Areas of Worklife Scale (AWS to assess the burnout state of Vietnamese clinical nurses and to develop a causal model of burnout of clinical nurses. Methods: We conducted a descriptive design using a cross-sectional survey. The questionnaire was hand divided directly by nursing departments to 500 clinical nurses in three hospitals. Vietnamese MBI-GS and AWS were then examined for reliability and validity. We used the revised exhaustion +1 burnout classification to access burnout state. We performed path analysis to develop a Vietnamese causal model based on the original model by Leiter and Maslach's theory. Results: We found that both scales were reliable and valid for assessing burnout. Among nurse participants, the percentage of severe burnout was 0.7% and burnout was 15.8%, and 17.2% of nurses were exhausted. The best predictor of burnout was “on-duty work schedule” that clinical nurses have to work for 24 hours. In the causal model, we also found similarity and difference pathways in comparison with the original model. Conclusion: Vietnamese MBI-GS and AWS were applicable to research on occupational stress. Nearly one-fifth of Vietnamese clinical nurses were working in burnout state. The causal model suggested a range of factors resulting in burnout, and it is necessary to consider the specific solution to prevent burnout problem. Keywords: burnout, nurses, Vietnam
Conceptual Models and Theory-Embedded Principles on Effective Schooling.
Scheerens, Jaap
1997-01-01
Reviews models and theories on effective schooling. Discusses four rationality-based organization theories and a fifth perspective, chaos theory, as applied to organizational functioning. Discusses theory-embedded principles flowing from these theories: proactive structuring, fit, market mechanisms, cybernetics, and self-organization. The…
A Study towards Building An Optimal Graph Theory Based Model For The Design of Tourism Website
Panigrahi, Goutam; Das, Anirban; Basu, Kajla
2010-10-01
Effective tourism website is a key to attract tourists from different parts of the world. Here we identify the factors of improving the effectiveness of website by considering it as a graph, where web pages including homepage are the nodes and hyperlinks are the edges between the nodes. In this model, the design constraints for building a tourism website are taken into consideration. Our objectives are to build a framework of an effective tourism website providing adequate level of information, service and also to enable the users to reach to the desired page by spending minimal loading time. In this paper an information hierarchy specifying the upper limit of outgoing link of a page has also been proposed. Following the hierarchy, the web developer can prepare an effective tourism website. Here loading time depends on page size and network traffic. We have assumed network traffic as uniform and the loading time is directly proportional with page size. This approach is done by quantifying the link structure of a tourism website. In this approach we also propose a page size distribution pattern of a tourism website.
Model Theory in Algebra, Analysis and Arithmetic
Dries, Lou; Macpherson, H Dugald; Pillay, Anand; Toffalori, Carlo; Wilkie, Alex J
2014-01-01
Presenting recent developments and applications, the book focuses on four main topics in current model theory: 1) the model theory of valued fields; 2) undecidability in arithmetic; 3) NIP theories; and 4) the model theory of real and complex exponentiation. Young researchers in model theory will particularly benefit from the book, as will more senior researchers in other branches of mathematics.
Diogo, V.; van der Hilst, Floortje; van Eijck, Janske; Faaij, André; Verstegen, Judith; Hilbert, J.; Carballo, S.; Volante, J.
2014-01-01
In this paper, a land-use modelling framework is presented combining empirical and theory-based modelling approaches to determine economic potential of biofuel production avoiding indirect land-use changes (iLUC) resulting from land competition with other functions. The empirical approach explores
Diogo, V.; van der Hilst, F.; van Eijck, J.; Verstegen, J.A.; Hilbert, J.; Carballo, S.; Volante, J.; Faaij, A.
2014-01-01
In this paper, a land-use modelling framework is presented combining empirical and theory-based modelling approaches to determine economic potential of biofuel production avoiding indirect land-use changes (iLUC) resulting from land competition with other functions. The empirical approach explores
Directory of Open Access Journals (Sweden)
Xue-wen Chen
2018-01-01
Full Text Available A fuzzy increment controller is designed aimed at the vibration system of automobile active suspension with seven degrees of freedom (DOF. For decreasing vibration, an active control force is acquired by created Proportion-Integration-Differentiation (PID controller. The controller’s parameters are adjusted by a fuzzy increment controller with self-modifying parameters functions, which adopts the deviation and its rate of change of the body’s vertical vibration velocity and the desired value in the position of the front and rear suspension as the input variables based on 49 fuzzy control rules. Adopting Simulink, the fuzzy increment controller is validated under different road excitation, such as the white noise input with four-wheel correlation in time-domain, the sinusoidal input, and the pulse input of C-grade road surface. The simulation results show that the proposed controller can reduce obviously the vehicle vibration compared to other independent control types in performance indexes, such as, the root mean square value of the body’s vertical vibration acceleration, pitching, and rolling angular acceleration.
Savre, J.; Ekman, A. M. L.
2015-05-01
A new parameterization for heterogeneous ice nucleation constrained by laboratory data and based on classical nucleation theory is introduced. Key features of the parameterization include the following: a consistent and modular modeling framework for treating condensation/immersion and deposition freezing, the possibility to consider various potential ice nucleating particle types (e.g., dust, black carbon, and bacteria), and the possibility to account for an aerosol size distribution. The ice nucleating ability of each aerosol type is described using a contact angle (θ) probability density function (PDF). A new modeling strategy is described to allow the θ PDF to evolve in time so that the most efficient ice nuclei (associated with the lowest θ values) are progressively removed as they nucleate ice. A computationally efficient quasi Monte Carlo method is used to integrate the computed ice nucleation rates over both size and contact angle distributions. The parameterization is employed in a parcel model, forced by an ensemble of Lagrangian trajectories extracted from a three-dimensional simulation of a springtime low-level Arctic mixed-phase cloud, in order to evaluate the accuracy and convergence of the method using different settings. The same model setup is then employed to examine the importance of various parameters for the simulated ice production. Modeling the time evolution of the θ PDF is found to be particularly crucial; assuming a time-independent θ PDF significantly overestimates the ice nucleation rates. It is stressed that the capacity of black carbon (BC) to form ice in the condensation/immersion freezing mode is highly uncertain, in particular at temperatures warmer than -20°C. In its current version, the parameterization most likely overestimates ice initiation by BC.
1982-08-01
accomplish the task, (2) the instrumentality of task performance for job outcomes, and (3) the instrumentality of outcomes for need satisfaction . We...in this discussion: effort, performance , outcomes, and needs. In order to present briefly the conventional approach to the Vroom models, another...Presumably, this is the final event in the sequence of effort, performance , outcome, and need satisfaction . The actual research reported in expectancy
Directory of Open Access Journals (Sweden)
Bin Zhang
2017-06-01
Full Text Available By simulating the sound field of a round piston transducer with the Kirchhoff integral theorem and analyzing the shape of ultrasound beams and propagation characteristics in a metal container wall, this study presents a model for calculating the echo sound pressure by using the Kirchhoff paraxial approximation theory, based on which and according to different ultrasonic impedance between gas and liquid media, a method for detecting the liquid level from outside of sealed containers is proposed. Then, the proposed method is evaluated through two groups of experiments. In the first group, three kinds of liquid media with different ultrasonic impedance are used as detected objects; the echo sound pressure is calculated by using the proposed model under conditions of four sets of different wall thicknesses. The changing characteristics of the echo sound pressure in the entire detection process are analyzed, and the effects of different ultrasonic impedance of liquids on the echo sound pressure are compared. In the second group, taking water as an example, two transducers with different radii are selected to measure the liquid level under four sets of wall thickness. Combining with sound field characteristics, the influence of different size transducers on the pressure calculation and detection resolution are discussed and analyzed. Finally, the experimental results indicate that measurement uncertainly is better than ±5 mm, which meets the industrial inspection requirements.
Zhang, Bin; Song, Wen-Ai; Wei, Yue-Juan; Zhang, Dong-Song; Liu, Wen-Yi
2017-06-15
By simulating the sound field of a round piston transducer with the Kirchhoff integral theorem and analyzing the shape of ultrasound beams and propagation characteristics in a metal container wall, this study presents a model for calculating the echo sound pressure by using the Kirchhoff paraxial approximation theory, based on which and according to different ultrasonic impedance between gas and liquid media, a method for detecting the liquid level from outside of sealed containers is proposed. Then, the proposed method is evaluated through two groups of experiments. In the first group, three kinds of liquid media with different ultrasonic impedance are used as detected objects; the echo sound pressure is calculated by using the proposed model under conditions of four sets of different wall thicknesses. The changing characteristics of the echo sound pressure in the entire detection process are analyzed, and the effects of different ultrasonic impedance of liquids on the echo sound pressure are compared. In the second group, taking water as an example, two transducers with different radii are selected to measure the liquid level under four sets of wall thickness. Combining with sound field characteristics, the influence of different size transducers on the pressure calculation and detection resolution are discussed and analyzed. Finally, the experimental results indicate that measurement uncertainly is better than ±5 mm, which meets the industrial inspection requirements.
Directory of Open Access Journals (Sweden)
Balázs Gönci
2010-12-01
Full Text Available Because of its relevance to everyday life, the spreading of viral infections has been of central interest in a variety of scientific communities involved in fighting, preventing and theoretically interpreting epidemic processes. Recent large scale observations have resulted in major discoveries concerning the overall features of the spreading process in systems with highly mobile susceptible units, but virtually no data are available about observations of infection spreading for a very large number of immobile units. Here we present the first detailed quantitative documentation of percolation-type viral epidemics in a highly reproducible in vitro system consisting of tens of thousands of virtually motionless cells. We use a confluent astroglial monolayer in a Petri dish and induce productive infection in a limited number of cells with a genetically modified herpesvirus strain. This approach allows extreme high resolution tracking of the spatio-temporal development of the epidemic. We show that a simple model is capable of reproducing the basic features of our observations, i.e., the observed behaviour is likely to be applicable to many different kinds of systems. Statistical physics inspired approaches to our data, such as fractal dimension of the infected clusters as well as their size distribution, seem to fit into a percolation theory based interpretation. We suggest that our observations may be used to model epidemics in more complex systems, which are difficult to study in isolation.
Gönci, Balázs; Németh, Valéria; Balogh, Emeric; Szabó, Bálint; Dénes, Ádám; Környei, Zsuzsanna; Vicsek, Tamás
2010-12-20
Because of its relevance to everyday life, the spreading of viral infections has been of central interest in a variety of scientific communities involved in fighting, preventing and theoretically interpreting epidemic processes. Recent large scale observations have resulted in major discoveries concerning the overall features of the spreading process in systems with highly mobile susceptible units, but virtually no data are available about observations of infection spreading for a very large number of immobile units. Here we present the first detailed quantitative documentation of percolation-type viral epidemics in a highly reproducible in vitro system consisting of tens of thousands of virtually motionless cells. We use a confluent astroglial monolayer in a Petri dish and induce productive infection in a limited number of cells with a genetically modified herpesvirus strain. This approach allows extreme high resolution tracking of the spatio-temporal development of the epidemic. We show that a simple model is capable of reproducing the basic features of our observations, i.e., the observed behaviour is likely to be applicable to many different kinds of systems. Statistical physics inspired approaches to our data, such as fractal dimension of the infected clusters as well as their size distribution, seem to fit into a percolation theory based interpretation. We suggest that our observations may be used to model epidemics in more complex systems, which are difficult to study in isolation.
Directory of Open Access Journals (Sweden)
Miguel ZAPATA-ROS
2015-04-01
Full Text Available This paper aims at setting the bases for the construction of a theoretical model of learning and of elaboration of knowledge, within connected learning environments. The starting point is a critical view of connectivism, and a premise: the study and recognition of existing theories, since their scope is still under development as regards their potentialities and affordances when applied in social, ubiquitous environments. The paper also includes reflections and a hypothesis on the causes that underlie in the origin of connectivism in its actual stage of development in the Information and Knowledge Society, in order to use the obtained conclusions as the bases of a new model, at a later phase.
International Nuclear Information System (INIS)
Tan, Zhongfu; Ju, Liwei; Reed, Brent; Rao, Rao; Peng, Daoxin; Li, Huanhuan; Pan, Ge
2015-01-01
Highlights: • Our research focuses on demand response behaviors of multi-type customers. • A wind power simulation method is proposed based on the Brownian motion theory. • Demand response revenue functions are proposed for multi-type customers. • A robust stochastic optimization model is proposed for wind power consumptive. • Models are built to measure the impacts of demand response on wind power consumptive. - Abstract: In order to relieve the influence of wind power uncertainty on power system operation, demand response and robust stochastic theory are introduced to build a stochastic scheduling optimization model. Firstly, this paper presents a simulation method for wind power considering external environment based on Brownian motion theory. Secondly, price-based demand response and incentive-based demand response are introduced to build demand response model. Thirdly, the paper constructs the demand response revenue functions for electric vehicle customers, business customers, industry customers and residential customers. Furthermore, robust stochastic optimization theory is introduced to build a wind power consumption stochastic optimization model. Finally, simulation analysis is taken in the IEEE 36 nodes 10 units system connected with 650 MW wind farms. The results show the robust stochastic optimization theory is better to overcome wind power uncertainty. Demand response can improve system wind power consumption capability. Besides, price-based demand response could transform customers’ load demand distribution, but its load curtailment capacity is not as obvious as incentive-based demand response. Since price-based demand response cannot transfer customer’s load demand as the same as incentive-based demand response, the comprehensive optimization effect will reach best when incentive-based demand response and price-based demand response are both introduced.
Computer-based theory of strategies
Energy Technology Data Exchange (ETDEWEB)
Findler, N V
1983-01-01
Some of the objectives and working tools of a new area of study, tentatively called theory of strategies, are described. It is based on the methodology of artificial intelligence, decision theory, operations research and digital gaming. The latter refers to computing activity that incorporates model building, simulation and learning programs in conflict situations. Three long-term projects which aim at automatically analyzing and synthesizing strategies are discussed. 27 references.
DEFF Research Database (Denmark)
Tian, Yihui; Govindan, Kannan; Zhu, Qinghua
2014-01-01
In this study, a system dynamics (SD) model is developed to guide the subsidy policies to promote the diffusion of green supply chain management (GSCM) in China. The relationships of stakeholders such as government, enterprises and consumers are analyzed through evolutionary game theory. Finally...
Zingl, Manuel; Nuss, Martin; Bauernfeind, Daniel; Aichhorn, Markus
2018-05-01
Recently solvers for the Anderson impurity model (AIM) working directly on the real-frequency axis have gained much interest. A simple and yet frequently used impurity solver is exact diagonalization (ED), which is based on a discretization of the AIM bath degrees of freedom. Usually, the bath parameters cannot be obtained directly on the real-frequency axis, but have to be determined by a fit procedure on the Matsubara axis. In this work we present an approach where the bath degrees of freedom are first discretized directly on the real-frequency axis using a large number of bath sites (≈ 50). Then, the bath is optimized by unitary transformations such that it separates into two parts that are weakly coupled. One part contains the impurity site and its interacting Green's functions can be determined with ED. The other (larger) part is a non-interacting system containing all the remaining bath sites. Finally, the Green's function of the full AIM is calculated via coupling these two parts with cluster perturbation theory.
Directory of Open Access Journals (Sweden)
Annisa N. Insany
2015-06-01
Full Text Available High prevalence of self medication with antibiotics can increase the probability of irrational use of antibiotics which may lead antibiotics resistance. Thus, shifting of behavior is required to minimize the irrational use of antibiotics. This study was aimed to determine the association between public perceived value and self-medication with antibiotics which can be used to develop an intervention model in order to reduce the practice of self-medication with antibiotics. An observational study was conducted during the period of November–December 2014.The subjects were patients who visit primary health care facilities in Bandung. A structured-interview that has been validated was used to investigate the association between perceived value and self-medication behavior based on the Health Belief Model theory (perceived susceptibility, benefits, barrier, and cues to action. Approximately 506 respondents were drawn randomly from 43 community healthcare centers and 8 pharmacies. Data was analyzed by using descriptive statistics and logistic regression (CI 95%, α = 5%. Validity and reliability of the questionnaire were shown with a correlation coefficient of >0.3 and a cronbach-alpha value of 0.719, respectively. We found that 29.45% of respondents practiced self-medication with antibiotics over the last six months. Additionally, there was no significant association between the perceived susceptibility, benefits, barrier, and cues to action with self-medication behavior (p>0.05. Easiness to access antibiotics without prescription was presumed as a factor that contribute to self-medication with antibiotics, therefore strict regulation in antibiotics use is very needed as a basic intervention to decrease self-medication with antibiotic.
Minisuperspace models in histories theory
International Nuclear Information System (INIS)
Anastopoulos, Charis; Savvidou, Ntina
2005-01-01
We study the Robertson-Walker minisuperspace model in histories theory, motivated by the results that emerged from the histories approach to general relativity. We examine, in particular, the issue of time reparametrization in such systems. The model is quantized using an adaptation of reduced state space quantization. We finally discuss the classical limit, the implementation of initial cosmological conditions and estimation of probabilities in the histories context
Sears, Nancy A
2002-01-01
Case management has developed in a variety of health care, social service, and insurance industries. Its historical pattern of development has resulted in practices that are generally administrative and technical in nature as well as being relatively generic and often undifferentiated between being a role and process. Research over the last decade has resulted in the opportunity to move case management practice for home care into a structured theory-based model and practice. Design and implementation of a specialized advanced practice care management model reflective of care management research and theory design by British researchers is beginning to show clinical and systemic results that should be replicable in other regions.
Lachowicz, Mirosław
2016-03-01
The very stimulating paper [6] discusses an approach to perception and learning in a large population of living agents. The approach is based on a generalization of kinetic theory methods in which the interactions between agents are described in terms of game theory. Such an approach was already discussed in Ref. [2-4] (see also references therein) in various contexts. The processes of perception and learning are based on the interactions between agents and therefore the general kinetic theory is a suitable tool for modeling them. However the main question that rises is how the perception and learning processes may be treated in the mathematical modeling. How may we precisely deliver suitable mathematical structures that are able to capture various aspects of perception and learning?
Directory of Open Access Journals (Sweden)
Rena R. Timirualeeva
2015-01-01
Full Text Available The article describes the methodology of modeling andstructuring of business networks theory. Accounting ofenvironmental factors mega-, macro- and mesolevels, theinternal state of the managed system and the error management command execution by control system implemented inthis. The proposed methodology can improve the quality of enterprise management of resort complex through a moreﬂexible response to changes in the parameters of the internaland external environments.
Directory of Open Access Journals (Sweden)
Manuel SÁNCHEZ-SANVICENTE
2012-08-01
Full Text Available La cultura organizacional se configura a partir de la interrelación de los procesos de apropiación de la filosofía, la pertenencia, la adaptación, la satisfacción y el liderazgo compartidos por un grupo. Este conjunto de categorías puede ser reconocido mediante el uso de una matriz que incluye en su estructura subcategorías o conceptos y un conjunto de propiedades observables en el público interno. El presente artículo tiene por objetivo describir un modelo de estudio construido a partir de la Grounded Theory o Teoría Fundamentada que nos permita comprender el desarrollo cultural de las organizaciones. El estudio de caso se realizó en una compañía líder en Europa del sector de la distribución.AbstractThe organizational culture is set from the interplay of the processes of appropriation of philosophy, membership, adaptation, satisfaction and leadership shared by a group. This set of categories can be recognized by using a matrix that includes in its structure or sub-concepts and a set of observable properties in the workforce. This article aims to describe a study model built from the Grounded Theory that allows us to understand the cultural development of organizations. The case study was conducted in a European leader in the distribution sector.
Bordogna, Clelia María; Albano, Ezequiel V.
2007-02-01
The aim of this paper is twofold. On the one hand we present a brief overview on the application of statistical physics methods to the modelling of social phenomena focusing our attention on models for opinion formation. On the other hand, we discuss and present original results of a model for opinion formation based on the social impact theory developed by Latané. The presented model accounts for the interaction among the members of a social group under the competitive influence of a strong leader and the mass media, both supporting two different states of opinion. Extensive simulations of the model are presented, showing that they led to the observation of a rich scenery of complex behaviour including, among others, critical behaviour and phase transitions between a state of opinion dominated by the leader and another dominated by the mass media. The occurrence of interesting finite-size effects reveals that, in small communities, the opinion of the leader may prevail over that of the mass media. This observation is relevant for the understanding of social phenomena involving a finite number of individuals, in contrast to actual physical phase transitions that take place in the thermodynamic limit. Finally, we give a brief outlook of open questions and lines for future work.
International Nuclear Information System (INIS)
Bordogna, Clelia Maria; Albano, Ezequiel V
2007-01-01
The aim of this paper is twofold. On the one hand we present a brief overview on the application of statistical physics methods to the modelling of social phenomena focusing our attention on models for opinion formation. On the other hand, we discuss and present original results of a model for opinion formation based on the social impact theory developed by Latane. The presented model accounts for the interaction among the members of a social group under the competitive influence of a strong leader and the mass media, both supporting two different states of opinion. Extensive simulations of the model are presented, showing that they led to the observation of a rich scenery of complex behaviour including, among others, critical behaviour and phase transitions between a state of opinion dominated by the leader and another dominated by the mass media. The occurrence of interesting finite-size effects reveals that, in small communities, the opinion of the leader may prevail over that of the mass media. This observation is relevant for the understanding of social phenomena involving a finite number of individuals, in contrast to actual physical phase transitions that take place in the thermodynamic limit. Finally, we give a brief outlook of open questions and lines for future work
Zhang, Yufeng; Long, Man; Luo, Sida; Bao, Yu; Shen, Hanxia
2015-12-01
Transit route choice model is the key technology of public transit systems planning and management. Traditional route choice models are mostly based on expected utility theory which has an evident shortcoming that it cannot accurately portray travelers' subjective route choice behavior for their risk preferences are not taken into consideration. Cumulative prospect theory (CPT), a brand new theory, can be used to describe travelers' decision-making process under the condition of uncertainty of transit supply and risk preferences of multi-type travelers. The method to calibrate the reference point, a key parameter to CPT-based transit route choice model, determines the precision of the model to a great extent. In this paper, a new method is put forward to obtain the value of reference point which combines theoretical calculation and field investigation results. Comparing the proposed method with traditional method, it shows that the new method can promote the quality of CPT-based model by improving the accuracy in simulating travelers' route choice behaviors based on transit trip investigation from Nanjing City, China. The proposed method is of great significance to logical transit planning and management, and to some extent makes up the defect that obtaining the reference point is solely based on qualitative analysis.
DEFF Research Database (Denmark)
Scheuer, John Damm
interested in explaining how and why ideas travel in and out of organizations and become institutionalized in organizational fields. More specifically the paper focuses on the way actor-network theory and the concept of translation have been translated by researchers trying to understand institutionalization......Institutional and more practice-based perspectives on organizing and change are increasingly being combined in order to understand the micro-processes on which institutional "orders" are built and changed. The aim of this paper is to analyze how this work is done in practice by researchers...... processes related to ideas that travel from one place in time and space to another. The paper suggests that combining the concept of translation and theories about institutional change will make it possible to ground macro-sociological claims about how ideas travel and become institutionalized...
Quantum field theory and the standard model
Schwartz, Matthew D
2014-01-01
Providing a comprehensive introduction to quantum field theory, this textbook covers the development of particle physics from its foundations to the discovery of the Higgs boson. Its combination of clear physical explanations, with direct connections to experimental data, and mathematical rigor make the subject accessible to students with a wide variety of backgrounds and interests. Assuming only an undergraduate-level understanding of quantum mechanics, the book steadily develops the Standard Model and state-of-the-art calculation techniques. It includes multiple derivations of many important results, with modern methods such as effective field theory and the renormalization group playing a prominent role. Numerous worked examples and end-of-chapter problems enable students to reproduce classic results and to master quantum field theory as it is used today. Based on a course taught by the author over many years, this book is ideal for an introductory to advanced quantum field theory sequence or for independe...
Foundations of compositional model theory
Czech Academy of Sciences Publication Activity Database
Jiroušek, Radim
2011-01-01
Roč. 40, č. 6 (2011), s. 623-678 ISSN 0308-1079 R&D Projects: GA MŠk 1M0572; GA ČR GA201/09/1891; GA ČR GEICC/08/E010 Institutional research plan: CEZ:AV0Z10750506 Keywords : multidimensional probability distribution * conditional independence * graphical Markov model * composition of distributions Subject RIV: IN - Informatics, Computer Science Impact factor: 0.667, year: 2011 http://library.utia.cas.cz/separaty/2011/MTR/jirousek-foundations of compositional model theory.pdf
A Non-local Model for Transient Moisture Flow in Unsaturated Soils Based on the Peridynamic Theory
Jabakhanji, R.; Mohtar, R. H.
2012-12-01
A non-local, gradient free, formulation of the porous media flow problem in unsaturated soils was derived. It parallels the peridynamic theory, a non-local reformulation of solid mechanics presented by Silling. In the proposed model, the evolution of the state of a material point is driven by pairwise interactions with other points across finite distances. Flow and changes in moisture are the result of these interactions. Instead of featuring local gradients, the proposed model expresses the flow as a functional integral of the hydraulic potential field. The absence of spatial gradients, undefined at or on discontinuities, makes the model a good candidate for flow simulations in fractured soils. It also lends itself to coupling with peridynamic mechanical models for simulating crack formation triggered by shrinkage and swelling, and assessing their potential impact on a wide range of processes, such as infiltration, contaminant transport, slope stability and integrity of clay barriers. A description of the concept and an outline of the derivation and numerical implementation are presented. Simulation results of infiltration and drainage for 1D, single and two-layers soil columns, for three different soil types are also presented. The same simulations are repeated using HYDRUS-1D, a computer model using the classic local flow equation. We show that the proposed non-local formulation successfully reproduces the results from HYDRUS-1D. S.A. Silling, "Reformulation of Elasticity Theory for Discontinuities and Long-range Forces," Journal of the Mechanics and Physics of Solids 48, no. 1 (January 2000): 175-209. J. Simunek, M. Sejna, and M.T. Van Genuchten, "The HYDRUS-1D Software Package for Simulating the One-dimensional Movement of Water, Heat, and Multiple Solutes in Variably-saturated Media," University of California, Riverside, Research Reports 240 (2005).
Superfield theory and supermatrix model
International Nuclear Information System (INIS)
Park, Jeong-Hyuck
2003-01-01
We study the noncommutative superspace of arbitrary dimensions in a systematic way. Superfield theories on a noncommutative superspace can be formulated in two folds, through the star product formalism and in terms of the supermatrices. We elaborate the duality between them by constructing the isomorphism explicitly and relating the superspace integrations of the star product lagrangian or the superpotential to the traces of the supermatrices. We show there exists an interesting fine tuned commutative limit where the duality can be still maintained. Namely on the commutative superspace too, there exists a supermatrix model description for the superfield theory. We interpret the result in the context of the wave particle duality. The dual particles for the superfields in even and odd spacetime dimensions are D-instantons and D0-branes respectively to be consistent with the T-duality. (author)
International Nuclear Information System (INIS)
Korayem, M. H.; Khaksar, H.; Taheri, M.
2013-01-01
This article has dealt with the development and modeling of various contact theories for biological nanoparticles shaped as cylinders and circular crowned rollers for application in the manipulation of different biological micro/nanoparticles based on Atomic Force Microscope. First, the effective contact forces were simulated, and their impact on contact mechanics simulation was investigated. In the next step, the Hertz contact model was simulated and compared for gold and DNA nanoparticles with the three types of spherical, cylindrical, and circular crowned roller type contact geometries. Then by reducing the length of the cylindrical section in the circular crowned roller geometry, the geometry of the body was made to approach that of a sphere, and the results were compared for DNA nanoparticles. To anticipatory validate the developed theories, the results of the cylindrical and the circular crowned roller contacts were compared with the results of the existing spherical contact simulations. Following the development of these contact models for the manipulation of various biological micro/nanoparticles, the cylindrical and the circular crowned roller type contact theories were modeled based on the theories of Lundberg, Dowson, Nikpur, Heoprich, and Hertz for the manipulation of biological micro/nanoparticles. Then, for a more accurate validation, the results obtained from the simulations were compared with those obtained by the finite element method and with the experimental results available in previous articles. The previous research works on the simulation of nanomanipulation have mainly investigated the contact theories used in the manipulation of spherical micro/nanoparticles. However since in real biomanipulation situations, biological micro/nanoparticles of more complex shapes need to be displaced in biological environments, this article therefore has modeled and compared, for the first time, different contact theories for use in the biomanipulation of
Scarinci, Isabel C; Bandura, Lisa; Hidalgo, Bertha; Cherrington, Andrea
2012-01-01
The development of efficacious theory-based, culturally relevant interventions to promote cervical cancer prevention among underserved populations is crucial to the elimination of cancer disparities. The purpose of this article is to describe the development of a theory-based, culturally relevant intervention focusing on primary (sexual risk reduction) and secondary (Pap smear) prevention of cervical cancer among Latina immigrants using intervention mapping (IM). The PEN-3 and Health Belief Model provided theoretical guidance for the intervention development and implementation. IM provides a logical five-step framework in intervention development: delineating proximal program objectives, selecting theory-based intervention methods and strategies, developing a program plan, planning for adoption in implementation, and creating evaluation plans and instruments. We first conducted an extensive literature review and qualitatively examined the sociocultural factors associated with primary and secondary prevention of cervical cancer. We then proceeded to quantitatively validate the qualitative findings, which led to development matrices linking the theoretical constructs with intervention objectives and strategies as well as evaluation. IM was a helpful tool in the development of a theory-based, culturally relevant intervention addressing primary and secondary prevention among Latina immigrants.
Ranger, Jochen; Kuhn, Jörg-Tobias; Szardenings, Carsten
2016-05-01
Psychological tests are usually analysed with item response models. Recently, some alternative measurement models have been proposed that were derived from cognitive process models developed in experimental psychology. These models consider the responses but also the response times of the test takers. Two such models are the Q-diffusion model and the D-diffusion model. Both models can be calibrated with the diffIRT package of the R statistical environment via marginal maximum likelihood (MML) estimation. In this manuscript, an alternative approach to model calibration is proposed. The approach is based on weighted least squares estimation and parallels the standard estimation approach in structural equation modelling. Estimates are determined by minimizing the discrepancy between the observed and the implied covariance matrix. The estimator is simple to implement, consistent, and asymptotically normally distributed. Least squares estimation also provides a test of model fit by comparing the observed and implied covariance matrix. The estimator and the test of model fit are evaluated in a simulation study. Although parameter recovery is good, the estimator is less efficient than the MML estimator. © 2016 The British Psychological Society.
Laqua, Henryk; Kussmann, Jörg; Ochsenfeld, Christian
2018-03-28
The correct description of multi-reference electronic ground states within Kohn-Sham density functional theory (DFT) requires an ensemble-state representation, employing fractionally occupied orbitals. However, the use of fractional orbital occupation leads to non-normalized exact-exchange holes, resulting in large fractional-spin errors for conventional approximative density functionals. In this communication, we present a simple approach to directly include the exact-exchange-hole normalization into DFT. Compared to conventional functionals, our model strongly improves the description for multi-reference systems, while preserving the accuracy in the single-reference case. We analyze the performance of our proposed method at the example of spin-averaged atoms and spin-restricted bond dissociation energy surfaces.
Laqua, Henryk; Kussmann, Jörg; Ochsenfeld, Christian
2018-03-01
The correct description of multi-reference electronic ground states within Kohn-Sham density functional theory (DFT) requires an ensemble-state representation, employing fractionally occupied orbitals. However, the use of fractional orbital occupation leads to non-normalized exact-exchange holes, resulting in large fractional-spin errors for conventional approximative density functionals. In this communication, we present a simple approach to directly include the exact-exchange-hole normalization into DFT. Compared to conventional functionals, our model strongly improves the description for multi-reference systems, while preserving the accuracy in the single-reference case. We analyze the performance of our proposed method at the example of spin-averaged atoms and spin-restricted bond dissociation energy surfaces.
Models in cooperative game theory
Branzei, Rodica; Tijs, Stef
2008-01-01
This book investigates models in cooperative game theory in which the players have the possibility to cooperate partially. In a crisp game the agents are either fully involved or not involved at all in cooperation with some other agents, while in a fuzzy game players are allowed to cooperate with infinite many different participation levels, varying from non-cooperation to full cooperation. A multi-choice game describes the intermediate case in which each player may have a fixed number of activity levels. Different set and one-point solution concepts for these games are presented. The properties of these solution concepts and their interrelations on several classes of crisp, fuzzy, and multi-choice games are studied. Applications of the investigated models to many economic situations are indicated as well. The second edition is highly enlarged and contains new results and additional sections in the different chapters as well as one new chapter.
Scalco, Andrea; Noventa, Stefano; Sartori, Riccardo; Ceschi, Andrea
2017-05-01
During the last decade, the purchase of organic food within a sustainable consumption context has gained momentum. Consequently, the amount of research in the field has increased, leading in some cases to discrepancies regarding both methods and results. The present review examines those works that applied the theory of planned behavior (TPB; Ajzen, 1991) as a theoretical framework in order to understand and predict consumers' motivation to buy organic food. A meta-analysis has been conducted to assess the strength of the relationships between attitude, subjective norms, perceived behavioral control, and intention, as well as between intention and behavior. Results confirm the major role played by individual attitude in shaping buying intention, followed by subjective norms and perceived behavioral control. Intention-behavior shows a large effect size, few studies however explicitly reported such an association. Furthermore, starting from a pooled correlation matrix, a meta-analytic structural equation model has been applied to jointly evaluate the strength of the relationships among the factors of the original model. Results suggest the robustness of the TPB model. In addition, mediation analysis indicates a potential direct effect from subjective norms to individual attitude in the present context. Finally, some issues regarding methodological aspects of the application of the TPB within the context of organic food are discussed for further research developments. Copyright © 2017 Elsevier Ltd. All rights reserved.
Field theory and the Standard Model
Energy Technology Data Exchange (ETDEWEB)
Dudas, E [Orsay, LPT (France)
2014-07-01
This brief introduction to Quantum Field Theory and the Standard Model contains the basic building blocks of perturbation theory in quantum field theory, an elementary introduction to gauge theories and the basic classical and quantum features of the electroweak sector of the Standard Model. Some details are given for the theoretical bias concerning the Higgs mass limits, as well as on obscure features of the Standard Model which motivate new physics constructions.
Lattice models and conformal field theories
International Nuclear Information System (INIS)
Saleur, H.
1988-01-01
Theoretical studies concerning the connection between critical physical systems and the conformal theories are reviewed. The conformal theory associated to a critical (integrable) lattice model is derived. The obtention of the central charge, critical exponents and torus partition function, using renormalization group arguments, is shown. The quantum group structure, in the integrable lattice models, and the theory of Visaro algebra representations are discussed. The relations between off-critical integrable models and conformal theories, in finite geometries, are studied
Working memory: theories, models, and controversies.
Baddeley, Alan
2012-01-01
I present an account of the origins and development of the multicomponent approach to working memory, making a distinction between the overall theoretical framework, which has remained relatively stable, and the attempts to build more specific models within this framework. I follow this with a brief discussion of alternative models and their relationship to the framework. I conclude with speculations on further developments and a comment on the value of attempting to apply models and theories beyond the laboratory studies on which they are typically based.
A dynamical theory for the Rishon model
International Nuclear Information System (INIS)
Harari, H.; Seiberg, N.
1980-09-01
We propose a composite model for quarks and leptons based on an exact SU(3)sub(C)xSU(3)sub(H) gauge theory and two fundamental J=1/2 fermions: a charged T-rishon and a neutral V-rishon. Quarks, leptons and W-bosons are SU(3)sub(H)-singlet composites of rishons. A dynamically broken effective SU(3)sub(C)xSU(2)sub(L)xSU(2)sub(R)xU(1)sub(B-L) gauge theory emerges at the composite level. The theory is ''natural'', anomaly-free, has no fundamental scalar particles, and describes at least three generations of quarks and leptons. Several ''technicolor'' mechanisms are automatically present. (Author)
A Leadership Identity Development Model: Applications from a Grounded Theory
Komives, Susan R.; Mainella, Felicia C.; Longerbeam, Susan D.; Osteen, Laura; Owen, Julie E.
2006-01-01
This article describes a stage-based model of leadership identity development (LID) that resulted from a grounded theory study on developing a leadership identity (Komives, Owen, Longerbeam, Mainella, & Osteen, 2005). The LID model expands on the leadership identity stages, integrates the categories of the grounded theory into the LID model, and…
Polyacetylene and relativistic field-theory models
International Nuclear Information System (INIS)
Bishop, A.R.; Campbell, D.K.; Fesser, K.
1981-01-01
Connections between continuum, mean-field, adiabatic Peierls-Froehlich theory in the half-filled band limit and known field theory results are discussed. Particular attention is given to the phi 4 model and to the solvable N = 2 Gross-Neveu model. The latter is equivalent to the Peierls system at a static, semi-classical level. Based on this equivalence we note the prediction of both kink and polaron solitons in models of trans-(CH)/sub x/. Polarons in cis-(CH)/sub x/ are compared with those in the trans isomer. Optical absorption from polarons is described, and general experimental consequences of polarons in (CH)/sub x/ and other conjugated polymers is discussed
Wang, John T.; Pineda, Evan J.; Ranatunga, Vipul; Smeltzer, Stanley S.
2015-01-01
A simple continuum damage mechanics (CDM) based 3D progressive damage analysis (PDA) tool for laminated composites was developed and implemented as a user defined material subroutine to link with a commercially available explicit finite element code. This PDA tool uses linear lamina properties from standard tests, predicts damage initiation with an easy-to-implement Hashin-Rotem failure criteria, and in the damage evolution phase, evaluates the degradation of material properties based on the crack band theory and traction-separation cohesive laws. It follows Matzenmiller et al.'s formulation to incorporate the degrading material properties into the damaged stiffness matrix. Since nonlinear shear and matrix stress-strain relations are not implemented, correction factors are used for slowing the reduction of the damaged shear stiffness terms to reflect the effect of these nonlinearities on the laminate strength predictions. This CDM based PDA tool is implemented as a user defined material (VUMAT) to link with the Abaqus/Explicit code. Strength predictions obtained, using this VUMAT, are correlated with test data for a set of notched specimens under tension and compression loads.
Halo modelling in chameleon theories
Energy Technology Data Exchange (ETDEWEB)
Lombriser, Lucas; Koyama, Kazuya [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Li, Baojiu, E-mail: lucas.lombriser@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: baojiu.li@durham.ac.uk [Institute for Computational Cosmology, Ogden Centre for Fundamental Physics, Department of Physics, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE (United Kingdom)
2014-03-01
We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the gravitational modification in high-density regions. Thereby, we use a mass and environment dependent chameleon spherical collapse model, the Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White halo density profile, and the halo model. Furthermore, using the spherical collapse model, we extrapolate a chameleon mass-concentration scaling relation from a ΛCDM prescription calibrated to N-body simulations. We also provide constraints on the model parameters to ensure viability on local scales. We test our description of the halo mass function and nonlinear matter power spectrum against the respective observables extracted from large-volume and high-resolution N-body simulations in the limiting case of f(R) gravity, corresponding to a vanishing Brans-Dicke parameter. We find good agreement between the two; the halo model provides a good qualitative description of the shape of the relative enhancement of the f(R) matter power spectrum with respect to ΛCDM caused by the extra attractive gravitational force but fails to recover the correct amplitude. Introducing an effective linear power spectrum in the computation of the two-halo term to account for an underestimation of the chameleon suppression at intermediate scales in our approach, we accurately reproduce the measurements from the N-body simulations.
Halo modelling in chameleon theories
International Nuclear Information System (INIS)
Lombriser, Lucas; Koyama, Kazuya; Li, Baojiu
2014-01-01
We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the gravitational modification in high-density regions. Thereby, we use a mass and environment dependent chameleon spherical collapse model, the Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White halo density profile, and the halo model. Furthermore, using the spherical collapse model, we extrapolate a chameleon mass-concentration scaling relation from a ΛCDM prescription calibrated to N-body simulations. We also provide constraints on the model parameters to ensure viability on local scales. We test our description of the halo mass function and nonlinear matter power spectrum against the respective observables extracted from large-volume and high-resolution N-body simulations in the limiting case of f(R) gravity, corresponding to a vanishing Brans-Dicke parameter. We find good agreement between the two; the halo model provides a good qualitative description of the shape of the relative enhancement of the f(R) matter power spectrum with respect to ΛCDM caused by the extra attractive gravitational force but fails to recover the correct amplitude. Introducing an effective linear power spectrum in the computation of the two-halo term to account for an underestimation of the chameleon suppression at intermediate scales in our approach, we accurately reproduce the measurements from the N-body simulations
Stochastic models: theory and simulation.
Energy Technology Data Exchange (ETDEWEB)
Field, Richard V., Jr.
2008-03-01
Many problems in applied science and engineering involve physical phenomena that behave randomly in time and/or space. Examples are diverse and include turbulent flow over an aircraft wing, Earth climatology, material microstructure, and the financial markets. Mathematical models for these random phenomena are referred to as stochastic processes and/or random fields, and Monte Carlo simulation is the only general-purpose tool for solving problems of this type. The use of Monte Carlo simulation requires methods and algorithms to generate samples of the appropriate stochastic model; these samples then become inputs and/or boundary conditions to established deterministic simulation codes. While numerous algorithms and tools currently exist to generate samples of simple random variables and vectors, no cohesive simulation tool yet exists for generating samples of stochastic processes and/or random fields. There are two objectives of this report. First, we provide some theoretical background on stochastic processes and random fields that can be used to model phenomena that are random in space and/or time. Second, we provide simple algorithms that can be used to generate independent samples of general stochastic models. The theory and simulation of random variables and vectors is also reviewed for completeness.
Directory of Open Access Journals (Sweden)
Ying Jiang
2017-02-01
Full Text Available This paper presents a theoretical formalism for describing systems of semiflexible polymers, which can have density variations due to finite compressibility and exhibit an isotropic-nematic transition. The molecular architecture of the semiflexible polymers is described by a continuum wormlike-chain model. The non-bonded interactions are described through a functional of two collective variables, the local density and local segmental orientation tensor. In particular, the functional depends quadratically on local density-variations and includes a Maier–Saupe-type term to deal with the orientational ordering. The specified density-dependence stems from a free energy expansion, where the free energy of an isotropic and homogeneous homopolymer melt at some fixed density serves as a reference state. Using this framework, a self-consistent field theory is developed, which produces a Helmholtz free energy that can be used for the calculation of the thermodynamics of the system. The thermodynamic properties are analysed as functions of the compressibility of the model, for values of the compressibility realizable in mesoscopic simulations with soft interactions and in actual polymeric materials.
Aycinena, Ana Corina; Jennings, Kerri-Ann; Gaffney, Ann Ogden; Koch, Pamela A; Contento, Isobel R; Gonzalez, Monica; Guidon, Ela; Karmally, Wahida; Hershman, Dawn; Greenlee, Heather
2017-02-01
We developed a theory-based dietary change curriculum for Hispanic breast cancer survivors with the goal of testing the effects of the intervention on change in dietary intake of fruits/vegetables and fat in a randomized, clinical trial. Social cognitive theory and the transtheoretical model were used as theoretical frameworks to structure curriculum components using the Nutrition Education DESIGN Procedure. Formative assessments were conducted to identify facilitators and barriers common to Hispanic women and test the degree of difficulty and appropriateness of program materials. Focus groups provided valuable insight and informed preimplementation modifications to the dietary program. The result was a systematically planned, evidence-based, culturally tailored dietary intervention for Hispanic breast cancer survivors, ¡Cocinar Para Su Salud! (Cook for Your Health!). The methodology described here may serve as a framework for the development of future dietary interventions among diverse and minority populations. Short- and long-term study results will be reported elsewhere.
Quiver gauge theories and integrable lattice models
International Nuclear Information System (INIS)
Yagi, Junya
2015-01-01
We discuss connections between certain classes of supersymmetric quiver gauge theories and integrable lattice models from the point of view of topological quantum field theories (TQFTs). The relevant classes include 4d N=1 theories known as brane box and brane tilling models, 3d N=2 and 2d N=(2,2) theories obtained from them by compactification, and 2d N=(0,2) theories closely related to these theories. We argue that their supersymmetric indices carry structures of TQFTs equipped with line operators, and as a consequence, are equal to the partition functions of lattice models. The integrability of these models follows from the existence of extra dimension in the TQFTs, which emerges after the theories are embedded in M-theory. The Yang-Baxter equation expresses the invariance of supersymmetric indices under Seiberg duality and its lower-dimensional analogs.
Malekian, Negin; Habibi, Jafar; Zangooei, Mohammad Hossein; Aghakhani, Hojjat
2016-11-01
There are many cells with various phenotypic behaviors in cancer interacting with each other. For example, an apoptotic cell may induce apoptosis in adjacent cells. A living cell can also protect cells from undergoing apoptosis and necrosis. These survival and death signals are propagated through interaction pathways between adjacent cells called gap junctions. The function of these signals depends on the cellular context of the cell receiving them. For instance, a receiver cell experiencing a low level of oxygen may interpret a received survival signal as an apoptosis signal. In this study, we examine the effect of these signals on tumor growth. We make an evolutionary game theory component in order to model the signal propagation through gap junctions. The game payoffs are defined as a function of cellular context. Then, the game theory component is integrated into an agent-based model of tumor growth. After that, the integrated model is applied to ductal carcinoma in situ, a type of early stage breast cancer. Different scenarios are explored to observe the impact of the gap junction communication and parameters of the game theory component on cancer progression. We compare these scenarios by using the Wilcoxon signed-rank test. The Wilcoxon signed-rank test succeeds in proving a significant difference between the tumor growth of the model before and after considering the gap junction communication. The Wilcoxon signed-rank test also proves that the tumor growth significantly depends on the oxygen threshold of turning survival signals into apoptosis. In this study, the gap junction communication is modeled by using evolutionary game theory to illustrate its role at early stage cancers such as ductal carcinoma in situ. This work indicates that the gap junction communication and the oxygen threshold of turning survival signals into apoptosis can notably affect cancer progression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Siti N.H. Hadie, PhD
2018-04-01
بير في نطاق التحفيز الذاتي. بالإضافة إلى ذلك، لمست مجموعة التدخل تجربة تعلم جيدة من المحاضرات. الاستنتاجات: حفزت القواعد الإرشادية بنجاح المشاركة المعرفية للطلبة وخبرة التعلم، مما يدل على التحفيز الناجح للموارد ذات الصلة للطلبة. تحفيز هذه الموارد المعرفية ضروري لنجاح المعالجة المعرفية خصوصا عند تعلم موضوع صعب كعلم التشريح. Abstract: Objective: There is a need to create a standard interactive anatomy lecture that can engage students in their learning process. This study investigated the impact of a new lecturing guideline, the Cognitive Load Theory-based Lecture Model (CLT-bLM, on students' cognitive engagement and motivation. Methods: A randomised controlled trial involving 197 participants from three institutions was conducted. The control group attended a freestyle lecture on the gross anatomy of the heart, delivered by a qualified anatomist from each institution. The intervention group attended a CLT-bLM-based lecture on a similar topic, delivered by the same lecturer, three weeks thereafter. The lecturers had attended a CLT-bLM workshop that allowed them to prepare for the CLT-bLM-based lecture over the course of three weeks. The students' ratings on their cognitive engagement and internal motivation were evaluated immediately after the lecture using a validated Learners' Engagement and Motivation Questionnaire. The differences between variables were analysed and the results were triangulated with the focus group discussion findings that explored students' experience while attending the lecture. Results: The intervention group has a significantly higher level of cognitive engagement than the control group; however, no significant difference in internal motivation score was found. In addition, the
Wu, Qiang; Zhao, Dekang; Wang, Yang; Shen, Jianjun; Mu, Wenping; Liu, Honglei
2017-11-01
Water inrush from coal-seam floors greatly threatens mining safety in North China and is a complex process controlled by multiple factors. This study presents a mathematical assessment system for coal-floor water-inrush risk based on the variable-weight model (VWM) and unascertained measure theory (UMT). In contrast to the traditional constant-weight model (CWM), which assigns a fixed weight to each factor, the VWM varies with the factor-state value. The UMT employs the confidence principle, which is more effective in ordered partition problems than the maximum membership principle adopted in the former mathematical theory. The method is applied to the Datang Tashan Coal Mine in North China. First, eight main controlling factors are selected to construct the comprehensive evaluation index system. Subsequently, an incentive-penalty variable-weight model is built to calculate the variable weights of each factor. Then, the VWM-UMT model is established using the quantitative risk-grade divide of each factor according to the UMT. On this basis, the risk of coal-floor water inrush in Tashan Mine No. 8 is divided into five grades. For comparison, the CWM is also adopted for the risk assessment, and a differences distribution map is obtained between the two methods. Finally, the verification of water-inrush points indicates that the VWM-UMT model is powerful and more feasible and reasonable. The model has great potential and practical significance in future engineering applications.
Finite Unification: Theory, Models and Predictions
Heinemeyer, S; Zoupanos, G
2011-01-01
All-loop Finite Unified Theories (FUTs) are very interesting N=1 supersymmetric Grand Unified Theories (GUTs) realising an old field theory dream, and moreover have a remarkable predictive power due to the required reduction of couplings. The reduction of the dimensionless couplings in N=1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among them holding beyond the unification scale. Finiteness results from the fact that there exist RGI relations among dimensional couplings that guarantee the vanishing of all beta-functions in certain N=1 GUTs even to all orders. Furthermore developments in the soft supersymmetry breaking sector of N=1 GUTs and FUTs lead to exact RGI relations, i.e. reduction of couplings, in this dimensionful sector of the theory, too. Based on the above theoretical framework phenomenologically consistent FUTs have been constructed. Here we review FUT models based on the SU(5) and SU(3)^3 gauge groups and their predictions. Of particular interest is the Hig...
Theory-Based Evaluation Meets Ambiguity
DEFF Research Database (Denmark)
Dahler-Larsen, Peter
2017-01-01
As theory-based evaluation (TBE) engages in situations where multiple stakeholders help develop complex program theory about dynamic phenomena in politically contested settings, it becomes difficult to develop and use program theory without ambiguity. The purpose of this article is to explore...... ambiguity as a fruitful perspective that helps TBE face current challenges. Literatures in organization theory and political theory are consulted in order to cultivate the concept of ambiguity. Janus variables (which work in two ways) and other ambiguous aspects of program theories are classified...... and exemplified. Stances towards ambiguity are considered, as are concrete steps that TBE evaluators can take to identify and deal with ambiguity in TBE....
Jiao, Wen-jun; Min, Qing-wen; Li, Wen-hua; Fuller, Anthony M
2015-04-01
Integrated watershed management based on aquatic ecosystems has been increasingly acknowledged. Such a change in the philosophy of water environment management requires recognizing the carrying capacity of aquatic ecosystems for human society from a more general perspective. The concept of the water ecological carrying capacity is therefore put forward, which considers both water resources and water environment, connects socio-economic development to aquatic ecosystems and provides strong support for integrated watershed management. In this paper, the authors proposed an ESEF-based measure of water ecological carrying capacity and constructed ESEF-based models of water ecological footprint and capacity, aiming to evaluate water ecological carrying capacity with footprint methods. A regional model of Taihu Lake Basin was constructed and applied to evaluate the water ecological carrying capacity in Changzhou City which located in the upper reaches of the basin. Results showed that human demand for water ecosystem services in this city had exceeded the supply capacity of local aquatic ecosystems and the significant gap between demand and supply had jeopardized the sustainability of local aquatic ecosystems. Considering aqua-product provision, water supply and pollutant absorption in an integrated way, the scale of population and economy aquatic ecosystems in Changzhou could bear only 54% of the current status.
A QCD Model Using Generalized Yang-Mills Theory
International Nuclear Information System (INIS)
Wang Dianfu; Song Heshan; Kou Lina
2007-01-01
Generalized Yang-Mills theory has a covariant derivative, which contains both vector and scalar gauge bosons. Based on this theory, we construct a strong interaction model by using the group U(4). By using this U(4) generalized Yang-Mills model, we also obtain a gauge potential solution, which can be used to explain the asymptotic behavior and color confinement.
New Pathways between Group Theory and Model Theory
Fuchs, László; Goldsmith, Brendan; Strüngmann, Lutz
2017-01-01
This volume focuses on group theory and model theory with a particular emphasis on the interplay of the two areas. The survey papers provide an overview of the developments across group, module, and model theory while the research papers present the most recent study in those same areas. With introductory sections that make the topics easily accessible to students, the papers in this volume will appeal to beginning graduate students and experienced researchers alike. As a whole, this book offers a cross-section view of the areas in group, module, and model theory, covering topics such as DP-minimal groups, Abelian groups, countable 1-transitive trees, and module approximations. The papers in this book are the proceedings of the conference “New Pathways between Group Theory and Model Theory,” which took place February 1-4, 2016, in Mülheim an der Ruhr, Germany, in honor of the editors’ colleague Rüdiger Göbel. This publication is dedicated to Professor Göbel, who passed away in 2014. He was one of th...
He, Xueqin; Han, Lujia; Ge, Jinyi; Huang, Guangqun
2018-04-01
This study establishes an optimal mathematical modelling to rationally describe the dynamic changes and spatial distribution of temperature and oxygen concentration in the aerobic composting process using coupling mass-heat-momentum transfer based on the microbial mechanism. Two different conditional composting experiments, namely continuous aeration and intermittent aeration, were performed to verify the proposed model. The results show that the model accurately predicted the dynamic changes in temperature (case I: R 2 = 0.93, RMSE = 1.95 K; case II: R 2 = 0.86, RMSE = 4.69 K) and oxygen concentration (case I: R 2 = 0.90, RMSE = 1.26%; case II: R 2 = 0.75, RMSE = 2.93%) in the central point of compost substrates. It also systematically simulated fluctuations in oxygen concentration caused by boundary conditions and the spatial distribution of the actual temperature and oxygen concentration. The proposed model exhibits good applicability in simulating the actual working conditions of aerobic composting process. Copyright © 2018 Elsevier Ltd. All rights reserved.
Galaxy Alignments: Theory, Modelling & Simulations
Kiessling, Alina; Cacciato, Marcello; Joachimi, Benjamin; Kirk, Donnacha; Kitching, Thomas D.; Leonard, Adrienne; Mandelbaum, Rachel; Schäfer, Björn Malte; Sifón, Cristóbal; Brown, Michael L.; Rassat, Anais
2015-11-01
The shapes of galaxies are not randomly oriented on the sky. During the galaxy formation and evolution process, environment has a strong influence, as tidal gravitational fields in the large-scale structure tend to align nearby galaxies. Additionally, events such as galaxy mergers affect the relative alignments of both the shapes and angular momenta of galaxies throughout their history. These "intrinsic galaxy alignments" are known to exist, but are still poorly understood. This review will offer a pedagogical introduction to the current theories that describe intrinsic galaxy alignments, including the apparent difference in intrinsic alignment between early- and late-type galaxies and the latest efforts to model them analytically. It will then describe the ongoing efforts to simulate intrinsic alignments using both N-body and hydrodynamic simulations. Due to the relative youth of this field, there is still much to be done to understand intrinsic galaxy alignments and this review summarises the current state of the field, providing a solid basis for future work.
Applications of model theory to functional analysis
Iovino, Jose
2014-01-01
During the last two decades, methods that originated within mathematical logic have exhibited powerful applications to Banach space theory, particularly set theory and model theory. This volume constitutes the first self-contained introduction to techniques of model theory in Banach space theory. The area of research has grown rapidly since this monograph's first appearance, but much of this material is still not readily available elsewhere. For instance, this volume offers a unified presentation of Krivine's theorem and the Krivine-Maurey theorem on stable Banach spaces, with emphasis on the
Du, Chen-Zhao; Wu, Zhi-Sheng; Zhao, Na; Zhou, Zheng; Shi, Xin-Yuan; Qiao, Yan-Jiang
2016-10-01
To establish a rapid quantitative analysis method for online monitoring of chlorogenic acid in aqueous solution of Lonicera Japonica Flos extraction by using micro-electromechanical near infrared spectroscopy (MEMS-NIR). High performance liquid chromatography(HPLC) was used as reference method．Kennard-Stone (K-S) algorithm was used to divide sample sets, and partial least square(PLS) regression was adopted to establish the multivariate analysis model between the HPLC analysis contents and NIR spectra. The synergy interval partial least squares (SiPLS) was used to selected modeling waveband to establish PLS models. RPD was used to evaluate the prediction performance of the models. MDLs was calculated based on two types of error detection theory, on-line analytical modeling approach of Lonicera Japonica Flos extraction process was expressed scientifically by MDL. The result shows that the model established by multiplicative scatter correction(MSC) was the best, with the root mean square with cross validation(RMSECV), root mean square error of correction(RMSEC) and root mean square error of prediction(RMSEP) of chlorogenic acid as 1.707, 1.489, 2.362, respectively, the determination coefficient of the calibration model was 0.998 5, and the determination coefficient of the prediction was 0.988 1．The value of RPD is 9.468.The MDL (0.042 15 g•L⁻¹) selected by SiPLS is less than the original,which demonstrated that SiPLS was beneficial to improve the prediction performance of the model. In this study, a more accurate expression of the prediction performance of the model from the two types of error detection theory, to further illustrate MEMS-NIR spectroscopy can be used for on-line monitoring of Lonicera Japonica Flos extraction process. Copyright© by the Chinese Pharmaceutical Association.
Matias, Carla; O'Connor, Thomas G; Futh, Annabel; Scott, Stephen
2014-01-01
Conceptually and methodologically distinct models exist for assessing quality of parent-child relationships, but few studies contrast competing models or assess their overlap in predicting developmental outcomes. Using observational methodology, the current study examined the distinctiveness of attachment theory-based and social learning theory-based measures of parenting in predicting two key measures of child adjustment: security of attachment narratives and social acceptance in peer nominations. A total of 113 5-6-year-old children from ethnically diverse families participated. Parent-child relationships were rated using standard paradigms. Measures derived from attachment theory included sensitive responding and mutuality; measures derived from social learning theory included positive attending, directives, and criticism. Child outcomes were independently-rated attachment narrative representations and peer nominations. Results indicated that Attachment theory-based and Social Learning theory-based measures were modestly correlated; nonetheless, parent-child mutuality predicted secure child attachment narratives independently of social learning theory-based measures; in contrast, criticism predicted peer-nominated fighting independently of attachment theory-based measures. In young children, there is some evidence that attachment theory-based measures may be particularly predictive of attachment narratives; however, no single model of measuring parent-child relationships is likely to best predict multiple developmental outcomes. Assessment in research and applied settings may benefit from integration of different theoretical and methodological paradigms.
Platoon Dispersion Analysis Based on Diffusion Theory
Directory of Open Access Journals (Sweden)
Badhrudeen Mohamed
2017-01-01
Full Text Available Urbanization and gro wing demand for travel, causes the traffic system to work ineffectively in most urban areas leadin g to traffic congestion. Many approaches have been adopted to address this problem, one among them being the signal co-ordination. This can be achieved if the platoon of vehicles that gets discharged at one signal gets green at consecutive signals with minimal delay. However, platoons tend to get dispersed as they travel and this dispersion phenomenon should be taken into account for effective signal coordination. Reported studies in this area are from the homogeneous and lane disciplined traffic conditions. This paper analyse the platoon dispersion characteristics under heterogeneous and lane-less traffic conditions. Out of the various modeling techniques reported, the approach based on diffusion theory is used in this study. The diffusion theory based models so far assumed thedata to follow normal distribution. However, in the present study, the data was found to follow lognormal distribution and hence the implementation was carried out using lognormal distribution. The parameters of lognormal distribution were calibrated for the study condition. For comparison purpose, normal distribution was also calibrated and the results were evaluated. It was foun d that model with log normal distribution performed better in all cases than the o ne with normal distribution.
The Prediction of Item Parameters Based on Classical Test Theory and Latent Trait Theory
Anil, Duygu
2008-01-01
In this study, the prediction power of the item characteristics based on the experts' predictions on conditions try-out practices cannot be applied was examined for item characteristics computed depending on classical test theory and two-parameters logistic model of latent trait theory. The study was carried out on 9914 randomly selected students…
Energy Technology Data Exchange (ETDEWEB)
Frey, H. Christopher [North Carolina State University, Raleigh, NC (United States); Rhodes, David S. [North Carolina State University, Raleigh, NC (United States)
1999-04-30
This is Volume 1 of a two-volume set of reports describing work conducted at North Carolina State University sponsored by Grant Number DE-FG05-95ER30250 by the U.S. Department of Energy. The title of the project is “Quantitative Analysis of Variability and Uncertainty in Acid Rain Assessments.” The work conducted under sponsorship of this grant pertains primarily to two main topics: (1) development of new methods for quantitative analysis of variability and uncertainty applicable to any type of model; and (2) analysis of variability and uncertainty in the performance, emissions, and cost of electric power plant combustion-based NOx control technologies. These two main topics are reported separately in Volumes 1 and 2.
Directory of Open Access Journals (Sweden)
Delphine eFabre
2015-12-01
Full Text Available Cognitive dysfunction is one of the hallmark deficits of schizophrenia. A wide range of studies illustrate how it is strongly interconnected to clinical presentation and daily life functioning (see Green, 1996 and Green et al., 2000. Hence, cognition is an important treatment target in schizophrenia. To address the challenge of cognitive enhancement in schizophrenia, a large number of cognitive remediation programs have been developed and evaluated over the past several decades. First, an overview of these programs is presented highlighting their specificity to cognitive deficit in schizophrenia using an integrated method. In this case, cognitive training focuses on enhancing several elementary cognitive functions considered as a prerequisite to social skills or vocational training modules. These programs are based on the neurodevelopmental hypothesis of schizophrenia. However, moderate improvement for patients who benefit from these therapies has been observed as described in Wykes et al review (2011. Next, neuropsychological models of schizophrenia are then presented. They highlight the critical role of the internally generated intentions in appropriate willful actions. The cognitive control mechanism deals with this ability. Interestingly, available cognitive remediation programs have not been influenced by these models. Hence, we propose another alternative to set up a specific cognitive remediation program for schizophrenia patients by targeting the cognitive control mechanism. We describe the PrACTice program which is in the process of being validated.
Directory of Open Access Journals (Sweden)
Lefeng Cheng
2018-01-01
Full Text Available This paper develops a novel dynamic correction method for the reliability assessment of large oil-immersed power transformers. First, with the transformer oil-paper insulation system (TOPIS as the target of evaluation and the winding hot spot temperature (HST as the core point, an HST-based static ageing failure model is built according to the Weibull distribution and Arrhenius reaction law, in order to describe the transformer ageing process and calculate the winding HST for obtaining the failure rate and life expectancy of TOPIS. A grey target theory based dynamic correction model is then developed, combined with the data of Dissolved Gas Analysis (DGA in power transformer oil, in order to dynamically modify the life expectancy calculated by the built static model, such that the corresponding relationship between the state grade and life expectancy correction coefficient of TOPIS can be built. Furthermore, the life expectancy loss recovery factor is introduced to correct the life expectancy of TOPIS again. Lastly, a practical case study of an operating transformer has been undertaken, in which the failure rate curve after introducing dynamic corrections can be obtained for the reliability assessment of this transformer. The curve shows a better ability of tracking the actual reliability level of transformer, thus verifying the validity of the proposed method and providing a new way for transformer reliability assessment. This contribution presents a novel model for the reliability assessment of TOPIS, in which the DGA data, as a source of information for the dynamic correction, is processed based on the grey target theory, thus the internal faults of power transformer can be diagnosed accurately as well as its life expectancy updated in time, ensuring that the dynamic assessment values can commendably track and reflect the actual operation state of the power transformers.
The Scope of Usage-based Theory
Directory of Open Access Journals (Sweden)
Paul eIbbotson
2013-05-01
Full Text Available Usage-based approaches typically draw on a relatively small set of cognitive processes, such as categorization, analogy and chunking to explain language structure and function. The goal of this paper is to first review the extent to which the ‘cognitive commitment’ of usage-based theory has had success in explaining empirical findings across domains, including language acquisition, processing and typology. We then look at the overall strengths and weaknesses of usage-based theory and highlight where there are significant debates. Finally, we draw special attention to a set of culturally generated structural patterns that seem to lie beyond the explanation of core usage-based cognitive processes. In this context we draw a distinction between cognition permitting language structure versus cognition entailing language structure. As well as addressing the need for greater clarity on the mechanisms of generalizations and the fundamental units of grammar, we suggest that integrating culturally generated structures within existing cognitive models of use will generate tighter predictions about how language works.
Nakamura, M; Saito, K; Wakabayashi, M
1990-04-01
The purpose of this study was to investigate how attitude change is generated by the recipient's degree of attitude formation, evaluative-emotional elements contained in the persuasive messages, and source expertise as a peripheral cue in the persuasion context. Hypotheses based on the Attitude Formation Theory of Mizuhara (1982) and the Elaboration Likelihood Model of Petty and Cacioppo (1981, 1986) were examined. Eighty undergraduate students served as subjects in the experiment, the first stage of which involving manipulating the degree of attitude formation with respect to nuclear power development. Then, the experimenter presented persuasive messages with varying combinations of evaluative-emotional elements from a source with either high or low expertise on the subject. Results revealed a significant interaction effect on attitude change among attitude formation, persuasive message and the expertise of the message source. That is, high attitude formation subjects resisted evaluative-emotional persuasion from the high expertise source while low attitude formation subjects changed their attitude when exposed to the same persuasive message from a low expertise source. Results exceeded initial predictions based on the Attitude Formation Theory and the Elaboration Likelihood Model.
Theories, Models and Methodology in Writing Research
Rijlaarsdam, Gert; Bergh, van den Huub; Couzijn, Michel
1996-01-01
Theories, Models and Methodology in Writing Research describes the current state of the art in research on written text production. The chapters in the first part offer contributions to the creation of new theories and models for writing processes. The second part examines specific elements of the
Theory, modeling and simulation: Annual report 1993
Energy Technology Data Exchange (ETDEWEB)
Dunning, T.H. Jr.; Garrett, B.C.
1994-07-01
Developing the knowledge base needed to address the environmental restoration issues of the US Department of Energy requires a fundamental understanding of molecules and their interactions in insolation and in liquids, on surfaces, and at interfaces. To meet these needs, the PNL has established the Environmental and Molecular Sciences Laboratory (EMSL) and will soon begin construction of a new, collaborative research facility devoted to advancing the understanding of environmental molecular science. Research in the Theory, Modeling, and Simulation program (TMS), which is one of seven research directorates in the EMSL, will play a critical role in understanding molecular processes important in restoring DOE`s research, development and production sites, including understanding the migration and reactions of contaminants in soils and groundwater, the development of separation process for isolation of pollutants, the development of improved materials for waste storage, understanding the enzymatic reactions involved in the biodegradation of contaminants, and understanding the interaction of hazardous chemicals with living organisms. The research objectives of the TMS program are to apply available techniques to study fundamental molecular processes involved in natural and contaminated systems; to extend current techniques to treat molecular systems of future importance and to develop techniques for addressing problems that are computationally intractable at present; to apply molecular modeling techniques to simulate molecular processes occurring in the multispecies, multiphase systems characteristic of natural and polluted environments; and to extend current molecular modeling techniques to treat complex molecular systems and to improve the reliability and accuracy of such simulations. The program contains three research activities: Molecular Theory/Modeling, Solid State Theory, and Biomolecular Modeling/Simulation. Extended abstracts are presented for 89 studies.
Theory, modeling and simulation: Annual report 1993
International Nuclear Information System (INIS)
Dunning, T.H. Jr.; Garrett, B.C.
1994-07-01
Developing the knowledge base needed to address the environmental restoration issues of the US Department of Energy requires a fundamental understanding of molecules and their interactions in insolation and in liquids, on surfaces, and at interfaces. To meet these needs, the PNL has established the Environmental and Molecular Sciences Laboratory (EMSL) and will soon begin construction of a new, collaborative research facility devoted to advancing the understanding of environmental molecular science. Research in the Theory, Modeling, and Simulation program (TMS), which is one of seven research directorates in the EMSL, will play a critical role in understanding molecular processes important in restoring DOE's research, development and production sites, including understanding the migration and reactions of contaminants in soils and groundwater, the development of separation process for isolation of pollutants, the development of improved materials for waste storage, understanding the enzymatic reactions involved in the biodegradation of contaminants, and understanding the interaction of hazardous chemicals with living organisms. The research objectives of the TMS program are to apply available techniques to study fundamental molecular processes involved in natural and contaminated systems; to extend current techniques to treat molecular systems of future importance and to develop techniques for addressing problems that are computationally intractable at present; to apply molecular modeling techniques to simulate molecular processes occurring in the multispecies, multiphase systems characteristic of natural and polluted environments; and to extend current molecular modeling techniques to treat complex molecular systems and to improve the reliability and accuracy of such simulations. The program contains three research activities: Molecular Theory/Modeling, Solid State Theory, and Biomolecular Modeling/Simulation. Extended abstracts are presented for 89 studies
Cao, Bobo; Du, Jiuyao; Du, Dongmei; Sun, Haitao; Zhu, Xiao; Fu, Hui
2016-09-20
Cellulose dissolution mechanism in acetate-based ionic liquids was systematically studied in Nuclear Magnetic Resonance (NMR) spectra and Density Functional Theory (DFT) methods by using cellobiose and 1-butyl-3-methylimidazolium acetate (BmimAc) as a model system. The solubility of cellulose in ionic liquid increased with temperature increase in the range of 90-140°C. NMR spectra suggested OAc(-) preferred to form stronger hydrogen bonds with hydrogen of hydroxyl in cellulose. Electrostatic potential method was employed to predict the most possible reaction sites and locate the most stable configuration. Atoms in molecules (AIM) theory was used to study the features of bonds at bond critical points and the variations of bond types. Simultaneously, noncovalent interactions were characterized and visualized by employing reduced density gradient analysis combined with Visual Molecular Dynamics (VMD) program. Natural bond orbital (NBO) theory was applied to study the noncovalent nature and characterize the orbital interactions between cellobiose and Bmim[OAc]. Copyright © 2016 Elsevier Ltd. All rights reserved.
The Friction Theory for Viscosity Modeling
DEFF Research Database (Denmark)
Cisneros, Sergio; Zeberg-Mikkelsen, Claus Kjær; Stenby, Erling Halfdan
2001-01-01
, in the case when experimental information is available a more accurate modeling can be obtained by means of a simple tuning procedure. A tuned f-theory general model can deliver highly accurate viscosity modeling above the saturation pressure and good prediction of the liquid-phase viscosity at pressures......In this work the one-parameter friction theory (f-theory) general models have been extended to the viscosity prediction and modeling of characterized oils. It is demonstrated that these simple models, which take advantage of the repulsive and attractive pressure terms of cubic equations of state...... such as the SRK, PR and PRSV, can provide accurate viscosity prediction and modeling of characterized oils. In the case of light reservoir oils, whose properties are close to those of normal alkanes, the one-parameter f-theory general models can predict the viscosity of these fluids with good accuracy. Yet...
Theory-based interventions for contraception.
Lopez, Laureen M; Grey, Thomas W; Chen, Mario; Tolley, Elizabeth E; Stockton, Laurie L
2016-11-23
The explicit use of theory in research helps expand the knowledge base. Theories and models have been used extensively in HIV-prevention research and in interventions for preventing sexually transmitted infections (STIs). The health behavior field uses many theories or models of change. However, many educational interventions addressing contraception have no explicit theoretical base. To review randomized controlled trials (RCTs) that tested a theoretical approach to inform contraceptive choice and encourage or improve contraceptive use. To 1 November 2016, we searched for trials that tested a theory-based intervention for improving contraceptive use in PubMed, CENTRAL, POPLINE, Web of Science, ClinicalTrials.gov, and ICTRP. For the initial review, we wrote to investigators to find other trials. Included trials tested a theory-based intervention for improving contraceptive use. Interventions addressed the use of one or more methods for contraception. The reports provided evidence that the intervention was based on a specific theory or model. The primary outcomes were pregnancy and contraceptive choice or use. We assessed titles and abstracts identified during the searches. One author extracted and entered the data into Review Manager; a second author verified accuracy. We examined studies for methodological quality.For unadjusted dichotomous outcomes, we calculated the Mantel-Haenszel odds ratio (OR) with 95% confidence interval (CI). Cluster randomized trials used various methods of accounting for the clustering, such as multilevel modeling. Most reports did not provide information to calculate the effective sample size. Therefore, we presented the results as reported by the investigators. We did not conduct meta-analysis due to varied interventions and outcome measures. We included 10 new trials for a total of 25. Five were conducted outside the USA. Fifteen randomly assigned individuals and 10 randomized clusters. This section focuses on nine trials with high or
Haubt, R.
2016-06-01
This paper explores a Radical Collaborative Approach in the global and centralized Rock-Art Database project to find new ways to look at rock-art by making information more accessible and more visible through public contributions. It looks at rock-art through the Key Performance Indicator (KPI), identified with the latest Australian State of the Environment Reports to help develop a better understanding of rock-art within a broader Cultural and Indigenous Heritage context. Using a practice-led approach the project develops a conceptual collaborative model that is deployed within the RADB Management System. Exploring learning theory, human-based computation and participant motivation the paper develops a procedure for deploying collaborative functions within the interface design of the RADB Management System. The paper presents the results of the collaborative model implementation and discusses considerations for the next iteration of the RADB Universe within an Agile Development Approach.
Vocation in theology-based nursing theories.
Lundmark, Mikael
2007-11-01
By using the concepts of intrinsicality/extrinsicality as analytic tools, the theology-based nursing theories of Ann Bradshaw and Katie Eriksson are analyzed regarding their explicit and/or implicit understanding of vocation as a motivational factor for nursing. The results show that both theories view intrinsic values as guarantees against reducing nursing practice to mechanistic applications of techniques and as being a way of reinforcing a high ethical standard. The theories explicitly (Bradshaw) or implicitly (Eriksson) advocate a vocational understanding of nursing as being essential for nursing theories. Eriksson's theory has a potential for conceptualizing an understanding of extrinsic and intrinsic motivational factors for nursing but one weakness in the theory could be the risk of slipping over to moral judgments where intrinsic factors are valued as being superior to extrinsic. Bradshaw's theory is more complex and explicit in understanding the concept of vocation and is theologically more plausible, although also more confessional.
Gillison, Fiona; Stathi, Afroditi; Reddy, Prasuna; Perry, Rachel; Taylor, Gordon; Bennett, Paul; Dunbar, James; Greaves, Colin
2015-01-16
Process evaluation is important for improving theories of behavior change and behavioral intervention methods. The present study reports on the process outcomes of a pilot test of the theoretical model (the Process Model for Lifestyle Behavior Change; PMLBC) underpinning an evidence-informed, theory-driven, group-based intervention designed to promote healthy eating and physical activity for people with high cardiovascular risk. 108 people at high risk of diabetes or heart disease were randomized to a group-based weight management intervention targeting diet and physical activity plus usual care, or to usual care. The intervention comprised nine group based sessions designed to promote motivation, social support, self-regulation and understanding of the behavior change process. Weight loss, diet, physical activity and theoretically defined mediators of change were measured pre-intervention, and after four and 12 months. The intervention resulted in significant improvements in fiber intake (M between-group difference = 5.7 g/day, p behavior change, and the predicted mechanisms of change specified in the PMBLC were largely supported. Improvements in self-efficacy and understanding of the behavior change process were associated with engagement in coping planning and self-monitoring activities, and successful dietary change at four and 12 months. While participants reported improvements in motivational and social support variables, there was no effect of these, or of the intervention overall, on physical activity. The data broadly support the theoretical model for supporting some dietary changes, but not for physical activity. Systematic intervention design allowed us to identify where improvements to the intervention may be implemented to promote change in all proposed mediators. More work is needed to explore effective mechanisms within interventions to promote physical activity behavior.
Directory of Open Access Journals (Sweden)
Li Wang
2017-01-01
Full Text Available Traffic congestion is a common problem in many countries, especially in big cities. At present, China’s urban road traffic accidents occur frequently, the occurrence frequency is high, the accident causes traffic congestion, and accidents cause traffic congestion and vice versa. The occurrence of traffic accidents usually leads to the reduction of road traffic capacity and the formation of traffic bottlenecks, causing the traffic congestion. In this paper, the formation and propagation of traffic congestion are simulated by using the improved medium traffic model, and the control strategy of congestion dissipation is studied. From the point of view of quantitative traffic congestion, the paper provides the fact that the simulation platform of urban traffic integration is constructed, and a feasible data analysis, learning, and parameter calibration method based on RBF neural network is proposed, which is used to determine the corresponding decision support system. The simulation results prove that the control strategy proposed in this paper is effective and feasible. According to the temporal and spatial evolution of the paper, we can see that the network has been improved on the whole.
Silva, Elizabet; Pascoal, Patrícia M; Nobre, Pedro
2016-09-01
Dysfunctional beliefs about body appearance and cognitive distraction from body appearance during sexual activity have been associated with sexual problems, particularly in women. However, there are no studies examining the interplay between these dimensions and the mechanisms by which they affect sexual functioning. To examine the mediating role of cognitive distraction with body appearance on the relation between beliefs about appearance and sexual functioning. The study sample consisted of 426 heterosexual participants (129 men and 297 women) involved in an exclusive dyadic committed relationship who answered an online questionnaire. The Body Appearance Cognitive Distraction Scale, the Beliefs About Appearance Scale, the International Index of Erectile Function, and the Female Sexual Function Index. The findings indicated that cognitive distraction with body appearance fully mediated the relation between beliefs about appearance and sexual functioning in men and women. The results support the role of beliefs about appearance and cognitive distraction based on body appearance in predicting sexual functioning, reaffirming the role of cognitive models in explaining sexual functioning in men and women. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.
Chen, Zhao; Cao, Yanfeng; He, Shuaibing; Qiao, Yanjiang
2018-01-01
Action (" gongxiao " in Chinese) of traditional Chinese medicine (TCM) is the high recapitulation for therapeutic and health-preserving effects under the guidance of TCM theory. TCM-defined herbal properties (" yaoxing " in Chinese) had been used in this research. TCM herbal property (TCM-HP) is the high generalization and summary for actions, both of which come from long-term effective clinical practice in two thousands of years in China. However, the specific relationship between TCM-HP and action of TCM is complex and unclear from a scientific perspective. The research about this is conducive to expound the connotation of TCM-HP theory and is of important significance for the development of the TCM-HP theory. One hundred and thirty-three herbs including 88 heat-clearing herbs (HCHs) and 45 blood-activating stasis-resolving herbs (BAHRHs) were collected from reputable TCM literatures, and their corresponding TCM-HPs/actions information were collected from Chinese pharmacopoeia (2015 edition). The Kennard-Stone (K-S) algorithm was used to split 133 herbs into 100 calibration samples and 33 validation samples. Then, machine learning methods including supported vector machine (SVM), k-nearest neighbor (kNN) and deep learning methods including deep belief network (DBN), convolutional neutral network (CNN) were adopted to develop action classification models based on TCM-HP theory, respectively. In order to ensure robustness, these four classification methods were evaluated by using the method of tenfold cross validation and 20 external validation samples for prediction. As results, 72.7-100% of 33 validation samples including 17 HCHs and 16 BASRHs were correctly predicted by these four types of methods. Both of the DBN and CNN methods gave out the best results and their sensitivity, specificity, precision, accuracy were all 100.00%. Especially, the predicted results of external validation set showed that the performance of deep learning methods (DBN, CNN) were better
DEFF Research Database (Denmark)
Hansen, Morten Balle; Heilesen, J. B.
In the broader context of evaluation design, this paper examines and compares pros and cons of a theory-based approach to evaluation (TBE) with the Theory-Based Stakeholder evaluation (TSE) model, introduced by Morten Balle Hansen and Evert Vedung (Hansen and Vedung 2010). While most approaches...... to TBE construct one unitary theory of the program (Coryn et al. 2011), the TSE-model emphasizes the importance of keeping theories of diverse stakeholders apart. This paper applies the TSE-model to an evaluation study conducted by the Danish Evaluation Institute (EVA) of the Danish system of quality......-model, as an alternative to traditional program theory evaluation....
2014-01-01
Central to effective roadway design is the ability to understand how drivers behave as they traverse a segment of : roadway. While simple and complex microscopic models have been used over the years to analyse driver behaviour, : most models: 1.) inc...
Prastiwi, A. C.; Kholiq, A.; Setyarsih, W.
2018-03-01
The purposed of this study are to analyse reduction of students’ misconceptions after getting ECIRR with virtual simulation. The design of research is the pre-experimental design with One Group Pretest-Posttest Design. Subjects of this research were 36 students of class XI MIA-5 SMAN 1 Driyorejo Gresik 2015/2016 school year. Students misconceptions was determined by Three-tier Diagnostic Test. The result shows that the average percentage of misconceptions reduced on topics of ideal gas law, equation of ideal gases and kinetic theory of gases respectively are 38%, 34% and 38%.
Group theory for unified model building
International Nuclear Information System (INIS)
Slansky, R.
1981-01-01
The results gathered here on simple Lie algebras have been selected with attention to the needs of unified model builders who study Yang-Mills theories based on simple, local-symmetry groups that contain as a subgroup the SUsup(w) 2 x Usup(w) 1 x SUsup(c) 3 symmetry of the standard theory of electromagnetic, weak, and strong interactions. The major topics include, after a brief review of the standard model and its unification into a simple group, the use of Dynkin diagrams to analyze the structure of the group generators and to keep track of the weights (quantum numbers) of the representation vectors; an analysis of the subgroup structure of simple groups, including explicit coordinatizations of the projections in weight space; lists of representations, tensor products and branching rules for a number of simple groups; and other details about groups and their representations that are often helpful for surveying unified models, including vector-coupling coefficient calculations. Tabulations of representations, tensor products, and branching rules for E 6 , SO 10 , SU 6 , F 4 , SO 9 , SO 5 , SO 8 , SO 7 , SU 4 , E 7 , E 8 , SU 8 , SO 14 , SO 18 , SO 22 , and for completeness, SU 3 are included. (These tables may have other applications.) Group-theoretical techniques for analyzing symmetry breaking are described in detail and many examples are reviewed, including explicit parameterizations of mass matrices. (orig.)
The Scope of Usage-based Theory
Paul eIbbotson
2013-01-01
Usage-based approaches typically draw on a relatively small set of cognitive processes, such as categorization, analogy, and chunking to explain language structure and function. The goal of this paper is to first review the extent to which the “cognitive commitment” of usage-based theory has had success in explaining empirical findings across domains, including language acquisition, processing, and typology. We then look at the overall strengths and weaknesses of usage-based theory and highli...
Wavelet-Based Quantum Field Theory
Directory of Open Access Journals (Sweden)
Mikhail V. Altaisky
2007-11-01
Full Text Available The Euclidean quantum field theory for the fields $phi_{Delta x}(x$, which depend on both the position $x$ and the resolution $Delta x$, constructed in SIGMA 2 (2006, 046, on the base of the continuous wavelet transform, is considered. The Feynman diagrams in such a theory become finite under the assumption there should be no scales in internal lines smaller than the minimal of scales of external lines. This regularisation agrees with the existing calculations of radiative corrections to the electron magnetic moment. The transition from the newly constructed theory to a standard Euclidean field theory is achieved by integration over the scale arguments.
Directory of Open Access Journals (Sweden)
EunYoung Kim, PhD
2017-06-01
Conclusion: The results suggest there are mediating effects of loneliness and depression in the relationship between attachment anxiety and smartphone addiction. The hypothesized model was found to be a suitable model for predicting smartphone addiction among university students. Future study is required to find a causal path to prevent smartphone addiction among university students.
Zai, Wenjiao; Wang, Bo; Liu, Jichun; Shi, Haobo; Zeng, Pingliang
2018-02-01
The investment decision model of trans-regional transmission network in the context of Global Energy Internet was studied in this paper. The key factors affecting the trans-regional transmission network investment income: the income tax rate, the loan interest rate, the expected return on investment of the investment subject, the per capita GDP and so on were considered in the transmission network investment income model. First, according to the principle of system dynamics, the causality diagram of key factors was constructed. Then, the dynamic model of transmission investment decision was established. A case study of the power transmission network between China and Mongolia, through the simulation of the system dynamic model, the influence of the above key factors on the investment returns was analyzed, and the feasibility and effectiveness of the model was proved.
Cao, Yi; Lu, Ru; Tao, Wei
2014-01-01
The local item independence assumption underlying traditional item response theory (IRT) models is often not met for tests composed of testlets. There are 3 major approaches to addressing this issue: (a) ignore the violation and use a dichotomous IRT model (e.g., the 2-parameter logistic [2PL] model), (b) combine the interdependent items to form a…
Modeling Routinization in Games: An Information Theory Approach
DEFF Research Database (Denmark)
Wallner, Simon; Pichlmair, Martin; Hecher, Michael
2015-01-01
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......-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...
Constraint theory multidimensional mathematical model management
Friedman, George J
2017-01-01
Packed with new material and research, this second edition of George Friedman’s bestselling Constraint Theory remains an invaluable reference for all engineers, mathematicians, and managers concerned with modeling. As in the first edition, this text analyzes the way Constraint Theory employs bipartite graphs and presents the process of locating the “kernel of constraint” trillions of times faster than brute-force approaches, determining model consistency and computational allowability. Unique in its abundance of topological pictures of the material, this book balances left- and right-brain perceptions to provide a thorough explanation of multidimensional mathematical models. Much of the extended material in this new edition also comes from Phan Phan’s PhD dissertation in 2011, titled “Expanding Constraint Theory to Determine Well-Posedness of Large Mathematical Models.” Praise for the first edition: "Dr. George Friedman is indisputably the father of the very powerful methods of constraint theory...
Understanding women's mammography intentions: a theory-based investigation.
Naito, Mikako; O'Callaghan, Frances V; Morrissey, Shirley
2009-01-01
The present study compared the utility of two models (the Theory of Planned Behavior and Protection Motivation Theory) in identifying factors associated with intentions to undertake screening mammography, before and after an intervention. The comparison was made between the unique components of the two models. The effect of including implementation intentions was also investigated. Two hundred and fifty-one women aged 37 to 69 years completed questionnaires at baseline and following the delivery of a standard (control) or a protection motivation theory-based informational intervention. Hierarchical multiple regressions indicated that theory of planned behavior variables were associated with mammography intentions. Results also showed that inclusion of implementation intention in the model significantly increased the association with mammography intentions. The findings suggest that future interventions aiming to increase screening mammography participation should focus on the theory of planned behavior variables and that implementation intention should also be targeted.
Ran, Tao; Liu, Yong; Li, Hengzhi; Tang, Shaoxun; He, Zhixiong; Munteanu, Cristian R; González-Díaz, Humberto; Tan, Zhiliang; Zhou, Chuanshe
2016-07-27
The management of ruminant growth yield has economic importance. The current work presents a study of the spatiotemporal dynamic expression of Ghrelin and GHR at mRNA levels throughout the gastrointestinal tract (GIT) of kid goats under housing and grazing systems. The experiments show that the feeding system and age affected the expression of either Ghrelin or GHR with different mechanisms. Furthermore, the experimental data are used to build new Machine Learning models based on the Perturbation Theory, which can predict the effects of perturbations of Ghrelin and GHR mRNA expression on the growth yield. The models consider eight longitudinal GIT segments (rumen, abomasum, duodenum, jejunum, ileum, cecum, colon and rectum), seven time points (0, 7, 14, 28, 42, 56 and 70 d) and two feeding systems (Supplemental and Grazing feeding) as perturbations from the expected values of the growth yield. The best regression model was obtained using Random Forest, with the coefficient of determination R(2) of 0.781 for the test subset. The current results indicate that the non-linear regression model can accurately predict the growth yield and the key nodes during gastrointestinal development, which is helpful to optimize the feeding management strategies in ruminant production system.
Kim, EunYoung; Cho, Inhyo; Kim, Eun Joo
2017-06-01
This study investigated the mediating effects of loneliness and depression on the relationship between adult attachment and smartphone addiction in university students. A total of 200 university students participated in this study. The data was analysed using descriptive statistics, correlation analysis, and structural equation modeling. There were significant positive relationships between attachment anxiety, loneliness, depression, and smartphone addiction. However, attachment anxiety was not significantly correlated with smartphone addiction. The results also showed that loneliness did not directly mediate between attachment anxiety and smartphone addiction. In addition, loneliness and depression serially mediated between attachment anxiety and smartphone addiction. The results suggest there are mediating effects of loneliness and depression in the relationship between attachment anxiety and smartphone addiction. The hypothesized model was found to be a suitable model for predicting smartphone addiction among university students. Future study is required to find a causal path to prevent smartphone addiction among university students. Copyright © 2017. Published by Elsevier B.V.
Theories and Frameworks for Online Education: Seeking an Integrated Model
Picciano, Anthony G.
2017-01-01
This article examines theoretical frameworks and models that focus on the pedagogical aspects of online education. After a review of learning theory as applied to online education, a proposal for an integrated "Multimodal Model for Online Education" is provided based on pedagogical purpose. The model attempts to integrate the work of…
EunYoung Kim, PhD; Inhyo Cho, PhD; Eun Joo Kim, PhD
2017-01-01
Purpose: This study investigated the mediating effects of loneliness and depression on the relationship between adult attachment and smartphone addiction in university students. Methods: A total of 200 university students participated in this study. The data was analysed using descriptive statistics, correlation analysis, and structural equation modeling. Results: There were significant positive relationships between attachment anxiety, loneliness, depression, and smartphone addiction. ...
Reconstructing bidimensional scalar field theory models
International Nuclear Information System (INIS)
Flores, Gabriel H.; Svaiter, N.F.
2001-07-01
In this paper we review how to reconstruct scalar field theories in two dimensional spacetime starting from solvable Scrodinger equations. Theree different Schrodinger potentials are analyzed. We obtained two new models starting from the Morse and Scarf II hyperbolic potencials, the U (θ) θ 2 In 2 (θ 2 ) model and U (θ) = θ 2 cos 2 (In(θ 2 )) model respectively. (author)
Accounting bases of theory: Why they matter
Directory of Open Access Journals (Sweden)
Zafeer Nagdee
2016-11-01
Full Text Available It is widely agreed that contemporary accounting practice is largely based on the application of professional accounting standards rather than on the application of sound, academic bases of theory. This has led to uncertainty within the field which has in turn inhibited the ability of accounting to develop into a more robust academic discipline. In conducting a thematic analysis of existing literature, this study will identify and expand on three key themes which will collectively establish the argument positing that a lacking basis of accounting theory has impaired the scholastic development of accounting practice worldwide. By introducing this argument to the academic community, this study will expose the economic risks associated with accounting’s absent bases of theory and will consequently add value by highlighting the need for additional research into the development, clarification and refinement of accounting theories that will result in more useful accounting practices worldwide
McMullen, Heather; Griffiths, Chris; Leber, Werner; Greenhalgh, Trisha
2015-05-31
Complex intervention trials may require health care organisations to implement new service models. In a recent cluster randomised controlled trial, some participating organisations achieved high recruitment, whereas others found it difficult to assimilate the intervention and were low recruiters. We sought to explain this variation and develop a model to inform organisational participation in future complex intervention trials. The trial included 40 general practices in a London borough with high HIV prevalence. The intervention was offering a rapid HIV test as part of the New Patient Health Check. The primary outcome was mean CD4 cell count at diagnosis. The process evaluation consisted of several hundred hours of ethnographic observation, 21 semi-structured interviews and analysis of routine documents (e.g., patient leaflets, clinical protocols) and trial documents (e.g., inclusion criteria, recruitment statistics). Qualitative data were analysed thematically using--and, where necessary, extending--Greenhalgh et al.'s model of diffusion of innovations. Narrative synthesis was used to prepare case studies of four practices representing maximum variety in clinicians' interest in HIV (assessed by level of serological testing prior to the trial) and performance in the trial (high vs. low recruiters). High-recruiting practices were, in general though not invariably, also innovative practices. They were characterised by strong leadership, good managerial relations, readiness for change, a culture of staff training and available staff time ('slack resources'). Their front-line staff believed that patients might benefit from the rapid HIV test ('relative advantage'), were emotionally comfortable administering it ('compatibility'), skilled in performing it ('task issues') and made creative adaptations to embed the test in local working practices ('reinvention'). Early experience of a positive HIV test ('observability') appeared to reinforce staff commitment to recruiting
A course on basic model theory
Sarbadhikari, Haimanti
2017-01-01
This self-contained book is an exposition of the fundamental ideas of model theory. It presents the necessary background from logic, set theory and other topics of mathematics. Only some degree of mathematical maturity and willingness to assimilate ideas from diverse areas are required. The book can be used for both teaching and self-study, ideally over two semesters. It is primarily aimed at graduate students in mathematical logic who want to specialise in model theory. However, the first two chapters constitute the first introduction to the subject and can be covered in one-semester course to senior undergraduate students in mathematical logic. The book is also suitable for researchers who wish to use model theory in their work.
Collazo, Andrés A.
2018-01-01
A model derived from the theory of planned behavior was empirically assessed for understanding faculty intention to use student ratings for teaching improvement. A sample of 175 professors participated in the study. The model was statistically significant and had a very large explanatory power. Instrumental attitude, affective attitude, perceived…
Huong Thi Thu Nguyen, RN, MPH; Kazuyo Kitaoka, PhD; Masune Sukigara, PhD; Anh Lan Thai, PhD
2018-01-01
Purpose: This study aimed to create a Vietnamese version of both the Maslach Burnout Inventory-General Survey (MBI-GS) and Areas of Worklife Scale (AWS) to assess the burnout state of Vietnamese clinical nurses and to develop a causal model of burnout of clinical nurses. Methods: We conducted a descriptive design using a cross-sectional survey. The questionnaire was hand divided directly by nursing departments to 500 clinical nurses in three hospitals. Vietnamese MBI-GS and AWS were then exam...
Directory of Open Access Journals (Sweden)
Qu Yingying
2017-01-01
Full Text Available The Silk Road Fund is an important financial support of The Belt and Road Initiative, it has a strict investment operation process to realize the capital appreciation, so the withdrawal is crucial. This paper models the utility game and find the game mechanism between Silk Road Fund and target enterprise. And then we put forward some referential suggestions such as choosing suitable withdraw opportunity, perfecting talent team and information transmission mechanism,strengthening cooperation with local government, making effective use of gambling agreement and actively exploring new exit mode.
Gauge theories and integrable lattice models
International Nuclear Information System (INIS)
Witten, E.
1989-01-01
Investigations of new knot polynomials discovered in the last few years have shown them to be intimately connected with soluble models of two dimensional lattice statistical mechanics. In this paper, these results, which in time may illuminate the whole question of why integrable lattice models exist, are reconsidered from the point of view of three dimensional gauge theory. Expectation values of Wilson lines in three dimensional Chern-Simons gauge theories can be computed by evaluating the partition functions of certain lattice models on finite graphs obtained by projecting the Wilson lines to the plane. The models in question - previously considered in both the knot theory and statistical mechanics literature - are IRF models in which the local Boltzmann weights are the matrix elements of braiding matrices in rational conformal field theories. These matrix elements, in turn, can be represented in three dimensional gauge theory in terms of the expectation value of a certain tetrahedral configuration of Wilson lines. This representation makes manifest a surprising symmetry of the braiding matrix elements in conformal field theory. (orig.)
International Nuclear Information System (INIS)
Yoon, Heonjun; Youn, Byeng D; Kim, Heung Soo
2016-01-01
As a compact and durable design concept, piezoelectric energy harvesting skin (PEH skin) has been recently proposed for self-powered electronic device applications. This study aims to develop an electromechanically-coupled analytical model of PEH skin considering the inertia and stiffness effects of a piezoelectric patch. Based on Kirchhoff plate theory, Hamilton’s principle is used to derive the electromechanically-coupled differential equation of motion. Due to the geometric discontinuity of the piezoelectric patch, the Rayleigh–Ritz method is applied to calculate the natural frequency and corresponding mode shapes. The electrical circuit equation is derived from Gauss’s law. Output voltage is estimated by solving the equation of motion and electrical circuit equation, simultaneously. For the purpose of evaluating the predictive capability, the results of the electromechanically-coupled analytical model are compared with those of the finite element method in a hierarchical manner. The outstanding merits of the electromechanically-coupled analytical model of PEH skin are three-fold: (1) consideration of the inertia and stiffness effects of the piezoelectric patches; (2) physical parameterization between the two-dimensional mechanical configuration and piezoelectric transduction; (3) manipulability of the twisting modes of a cantilever plate with a small aspect ratio. (paper)
Theory analysis of the Dental Hygiene Human Needs Conceptual Model.
MacDonald, L; Bowen, D M
2017-11-01
Theories provide a structural knowing about concept relationships, practice intricacies, and intuitions and thus shape the distinct body of the profession. Capturing ways of knowing and being is essential to any professions' practice, education and research. This process defines the phenomenon of the profession - its existence or experience. Theory evaluation is a systematic criterion-based assessment of a specific theory. This study presents a theory analysis of the Dental Hygiene Human Needs Conceptual Model (DH HNCM). Using the Walker and Avant Theory Analysis, a seven-step process, the DH HNCM, was analysed and evaluated for its meaningfulness and contribution to dental hygiene. The steps include the following: (i) investigate the origins; (ii) examine relationships of the theory's concepts; (iii) assess the logic of the theory's structure; (iv) consider the usefulness to practice; (v) judge the generalizability; (vi) evaluate the parsimony; and (vii) appraise the testability of the theory. Human needs theory in nursing and Maslow's Hierarchy of Need Theory prompted this theory's development. The DH HNCM depicts four concepts based on the paradigm concepts of the profession: client, health/oral health, environment and dental hygiene actions, and includes validated eleven human needs that evolved overtime to eight. It is logical, simplistic, allows scientific predictions and testing, and provides a unique lens for the dental hygiene practitioner. With this model, dental hygienists have entered practice, knowing they enable clients to meet their human needs. For the DH HNCM, theory analysis affirmed that the model is reasonable and insightful and adds to the dental hygiene professions' epistemology and ontology. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Cluster model in reaction theory
International Nuclear Information System (INIS)
Adhikari, S.K.
1979-01-01
A recent work by Rosenberg on cluster states in reaction theory is reexamined and generalized to include energies above the threshold for breakup into four composite fragments. The problem of elastic scattering between two interacting composite fragments is reduced to an equivalent two-particle problem with an effective potential to be determined by extremum principles. For energies above the threshold for breakup into three or four composite fragments effective few-particle potentials are introduced and the problem is reduced to effective three- and four-particle problems. The equivalent three-particle equation contains effective two- and three-particle potentials. The effective potential in the equivalent four-particle equation has two-, three-, and four-body connected parts and a piece which has two independent two-body connected parts. In the equivalent three-particle problem we show how to include the effect of a weak three-body potential perturbatively. In the equivalent four-body problem an approximate simple calculational scheme is given when one neglects the four-particle potential the effect of which is presumably very small
Opera house acoustics based on subjective preference theory
Ando, Yoichi
2015-01-01
This book focuses on opera house acoustics based on subjective preference theory; it targets researchers in acoustics and vision who are working in physics, psychology, and brain physiology. This book helps readers to understand any subjective attributes in relation to objective parameters based on the powerful and workable model of the auditory system. It is reconfirmed here that the well-known Helmholtz theory, which was based on a peripheral model of the auditory system, may not well describe pitch, timbre, and duration as well as the spatial sensations described in this book, nor overall responses such as subjective preference of sound fields and the annoyance of environmental noise.
Economic Modelling in Institutional Economic Theory
Directory of Open Access Journals (Sweden)
Wadim Strielkowski
2017-06-01
Full Text Available Our paper is centered around the formation of theory of institutional modelling that includes principles and ideas reflecting the laws of societal development within the framework of institutional economic theory. We scrutinize and discuss the scientific principles of this institutional modelling that are increasingly postulated by the classics of institutional theory and find their way into the basics of the institutional economics. We propose scientific ideas concerning the new innovative approaches to institutional modelling. These ideas have been devised and developed on the basis of the results of our own original design, as well as on the formalisation and measurements of economic institutions, their functioning and evolution. Moreover, we consider the applied aspects of the institutional theory of modelling and employ them in our research for formalizing our results and maximising the practical outcome of our paper. Our results and findings might be useful for the researchers and stakeholders searching for the systematic and comprehensive description of institutional level modelling, the principles involved in this process and the main provisions of the institutional theory of economic modelling.
Randomized Item Response Theory Models
Fox, Gerardus J.A.
2005-01-01
The randomized response (RR) technique is often used to obtain answers on sensitive questions. A new method is developed to measure latent variables using the RR technique because direct questioning leads to biased results. Within the RR technique is the probability of the true response modeled by
Graphical Model Theory for Wireless Sensor Networks
International Nuclear Information System (INIS)
Davis, William B.
2002-01-01
Information processing in sensor networks, with many small processors, demands a theory of computation that allows the minimization of processing effort, and the distribution of this effort throughout the network. Graphical model theory provides a probabilistic theory of computation that explicitly addresses complexity and decentralization for optimizing network computation. The junction tree algorithm, for decentralized inference on graphical probability models, can be instantiated in a variety of applications useful for wireless sensor networks, including: sensor validation and fusion; data compression and channel coding; expert systems, with decentralized data structures, and efficient local queries; pattern classification, and machine learning. Graphical models for these applications are sketched, and a model of dynamic sensor validation and fusion is presented in more depth, to illustrate the junction tree algorithm
Topological quantum theories and integrable models
International Nuclear Information System (INIS)
Keski-Vakkuri, E.; Niemi, A.J.; Semenoff, G.; Tirkkonen, O.
1991-01-01
The path-integral generalization of the Duistermaat-Heckman integration formula is investigated for integrable models. It is shown that for models with periodic classical trajectories the path integral reduces to a form similar to the finite-dimensional Duistermaat-Heckman integration formula. This provides a relation between exactness of the stationary-phase approximation and Morse theory. It is also argued that certain integrable models can be related to topological quantum theories. Finally, it is found that in general the stationary-phase approximation presumes that the initial and final configurations are in different polarizations. This is exemplified by the quantization of the SU(2) coadjoint orbit
A study of the logical model of capital market complexity theories
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Analyzes the shortcomings of the classic capital market theories based on EMH and discloses the complexity essence of the capital market. Considering the capital market a complicated, interactive and adaptable dynamic system, with complexity science as the method for researching the operation law of the capital market, this paper constructs a nonlinear logical model to analyze the applied realm, focal point and interrelationship of such theories as dissipative structure theory, chaos theory, fractal theory, synergetics theory, catastrophe theory and scale theory, and summarizes and discusses the achievements and problems of each theory.Based on the research, the paper foretells the developing direction of complexity science in a capital market.
Self Modeling: Expanding the Theories of Learning
Dowrick, Peter W.
2012-01-01
Self modeling (SM) offers a unique expansion of learning theory. For several decades, a steady trickle of empirical studies has reported consistent evidence for the efficacy of SM as a procedure for positive behavior change across physical, social, educational, and diagnostic variations. SM became accepted as an extreme case of model similarity;…
Nematic elastomers: from a microscopic model to macroscopic elasticity theory.
Xing, Xiangjun; Pfahl, Stephan; Mukhopadhyay, Swagatam; Goldbart, Paul M; Zippelius, Annette
2008-05-01
A Landau theory is constructed for the gelation transition in cross-linked polymer systems possessing spontaneous nematic ordering, based on symmetry principles and the concept of an order parameter for the amorphous solid state. This theory is substantiated with help of a simple microscopic model of cross-linked dimers. Minimization of the Landau free energy in the presence of nematic order yields the neoclassical theory of the elasticity of nematic elastomers and, in the isotropic limit, the classical theory of isotropic elasticity. These phenomenological theories of elasticity are thereby derived from a microscopic model, and it is furthermore demonstrated that they are universal mean-field descriptions of the elasticity for all chemical gels and vulcanized media.
Big bang models in string theory
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes Pleinlaan 2, B-1050 Brussels (Belgium)
2006-11-07
These proceedings are based on lectures delivered at the 'RTN Winter School on Strings, Supergravity and Gauge Theories', CERN, 16-20 January 2006. The school was mainly aimed at PhD students and young postdocs. The lectures start with a brief introduction to spacetime singularities and the string theory resolution of certain static singularities. Then they discuss attempts to resolve cosmological singularities in string theory, mainly focusing on two specific examples: the Milne orbifold and the matrix big bang.
Security Theorems via Model Theory
Directory of Open Access Journals (Sweden)
Joshua Guttman
2009-11-01
Full Text Available A model-theoretic approach can establish security theorems for cryptographic protocols. Formulas expressing authentication and non-disclosure properties of protocols have a special form. They are quantified implications for all xs . (phi implies for some ys . psi. Models (interpretations for these formulas are *skeletons*, partially ordered structures consisting of a number of local protocol behaviors. *Realized* skeletons contain enough local sessions to explain all the behavior, when combined with some possible adversary behaviors. We show two results. (1 If phi is the antecedent of a security goal, then there is a skeleton A_phi such that, for every skeleton B, phi is satisfied in B iff there is a homomorphism from A_phi to B. (2 A protocol enforces for all xs . (phi implies for some ys . psi iff every realized homomorphic image of A_phi satisfies psi. Hence, to verify a security goal, one can use the Cryptographic Protocol Shapes Analyzer CPSA (TACAS, 2007 to identify minimal realized skeletons, or "shapes," that are homomorphic images of A_phi. If psi holds in each of these shapes, then the goal holds.
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.
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.
Edjolo, Arlette; Proust-Lima, Cécile; Delva, Fleur; Dartigues, Jean-François; Pérès, Karine
2016-02-15
We aimed to describe the hierarchical structure of Instrumental Activities of Daily Living (IADL) and basic Activities of Daily Living (ADL) and trajectories of dependency before death in an elderly population using item response theory methodology. Data were obtained from a population-based French cohort study, the Personnes Agées QUID (PAQUID) Study, of persons aged ≥65 years at baseline in 1988 who were recruited from 75 randomly selected areas in Gironde and Dordogne. We evaluated IADL and ADL data collected at home every 2-3 years over a 24-year period (1988-2012) for 3,238 deceased participants (43.9% men). We used a longitudinal item response theory model to investigate the item sequence of 11 IADL and ADL combined into a single scale and functional trajectories adjusted for education, sex, and age at death. The findings confirmed the earliest losses in IADL (shopping, transporting, finances) at the partial limitation level, and then an overlapping of concomitant IADL and ADL, with bathing and dressing being the earliest ADL losses, and finally total losses for toileting, continence, eating, and transferring. Functional trajectories were sex-specific, with a benefit of high education that persisted until death in men but was only transient in women. An in-depth understanding of this sequence provides an early warning of functional decline for better adaptation of medical and social care in the elderly. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Development of a dynamic computational model of social cognitive theory.
Riley, William T; Martin, Cesar A; Rivera, Daniel E; Hekler, Eric B; Adams, Marc A; Buman, Matthew P; Pavel, Misha; King, Abby C
2016-12-01
Social cognitive theory (SCT) is among the most influential theories of behavior change and has been used as the conceptual basis of health behavior interventions for smoking cessation, weight management, and other health behaviors. SCT and other behavior theories were developed primarily to explain differences between individuals, but explanatory theories of within-person behavioral variability are increasingly needed as new technologies allow for intensive longitudinal measures and interventions adapted from these inputs. These within-person explanatory theoretical applications can be modeled as dynamical systems. SCT constructs, such as reciprocal determinism, are inherently dynamical in nature, but SCT has not been modeled as a dynamical system. This paper describes the development of a dynamical system model of SCT using fluid analogies and control systems principles drawn from engineering. Simulations of this model were performed to assess if the model performed as predicted based on theory and empirical studies of SCT. This initial model generates precise and testable quantitative predictions for future intensive longitudinal research. Dynamic modeling approaches provide a rigorous method for advancing health behavior theory development and refinement and for guiding the development of more potent and efficient interventions.
Vacation queueing models theory and applications
Tian, Naishuo
2006-01-01
A classical queueing model consists of three parts - arrival process, service process, and queue discipline. However, a vacation queueing model has an additional part - the vacation process which is governed by a vacation policy - that can be characterized by three aspects: 1) vacation start-up rule; 2) vacation termination rule, and 3) vacation duration distribution. Hence, vacation queueing models are an extension of classical queueing theory. Vacation Queueing Models: Theory and Applications discusses systematically and in detail the many variations of vacation policy. By allowing servers to take vacations makes the queueing models more realistic and flexible in studying real-world waiting line systems. Integrated in the book's discussion are a variety of typical vacation model applications that include call centers with multi-task employees, customized manufacturing, telecommunication networks, maintenance activities, etc. Finally, contents are presented in a "theorem and proof" format and it is invaluabl...
International Nuclear Information System (INIS)
Schlingemann, D.
1996-10-01
Several two dimensional quantum field theory models have more than one vacuum state. An investigation of super selection sectors in two dimensions from an axiomatic point of view suggests that there should be also states, called soliton or kink states, which interpolate different vacua. Familiar quantum field theory models, for which the existence of kink states have been proven, are the Sine-Gordon and the φ 4 2 -model. In order to establish the existence of kink states for a larger class of models, we investigate the following question: Which are sufficient conditions a pair of vacuum states has to fulfill, such that an interpolating kink state can be constructed? We discuss the problem in the framework of algebraic quantum field theory which includes, for example, the P(φ) 2 -models. We identify a large class of vacuum states, including the vacua of the P(φ) 2 -models, the Yukawa 2 -like models and special types of Wess-Zumino models, for which there is a natural way to construct an interpolating kink state. In two space-time dimensions, massive particle states are kink states. We apply the Haag-Ruelle collision theory to kink sectors in order to analyze the asymptotic scattering states. We show that for special configurations of n kinks the scattering states describe n freely moving non interacting particles. (orig.)
Scaling theory of depinning in the Sneppen model
International Nuclear Information System (INIS)
Maslov, S.; Paczuski, M.
1994-01-01
We develop a scaling theory for the critical depinning behavior of the Sneppen interface model [Phys. Rev. Lett. 69, 3539 (1992)]. This theory is based on a ''gap'' equation that describes the self-organization process to a critical state of the depinning transition. All of the critical exponents can be expressed in terms of two independent exponents, ν parallel (d) and ν perpendicular (d), characterizing the divergence of the parallel and perpendicular correlation lengths as the interface approaches its dynamical attractor
A Performance-Based Instructional Theory
Lawson, Tom E.
1974-01-01
The rationale for a performanced- based instructional theory has arisen from significant advances during the past several years in instructional psychology. Four major areas of concern are: analysis of subject-matter content in terms of performance competencies, diagnosis of pre-instructional behavior, formulation of an instructional…
Jigsaw Cooperative Learning: Acid-Base Theories
Tarhan, Leman; Sesen, Burcin Acar
2012-01-01
This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…
Marrero-Ponce, Yovani; Martínez-Albelo, Eugenio R; Casañola-Martín, Gerardo M; Castillo-Garit, Juan A; Echevería-Díaz, Yunaimy; Zaldivar, Vicente Romero; Tygat, Jan; Borges, José E Rodriguez; García-Domenech, Ramón; Torrens, Francisco; Pérez-Giménez, Facundo
2010-11-01
Novel bond-level molecular descriptors are proposed, based on linear maps similar to the ones defined in algebra theory. The kth edge-adjacency matrix (E(k)) denotes the matrix of bond linear indices (non-stochastic) with regard to canonical basis set. The kth stochastic edge-adjacency matrix, ES(k), is here proposed as a new molecular representation easily calculated from E(k). Then, the kth stochastic bond linear indices are calculated using ES(k) as operators of linear transformations. In both cases, the bond-type formalism is developed. The kth non-stochastic and stochastic total linear indices are calculated by adding the kth non-stochastic and stochastic bond linear indices, respectively, of all bonds in molecule. First, the new bond-based molecular descriptors (MDs) are tested for suitability, for the QSPRs, by analyzing regressions of novel indices for selected physicochemical properties of octane isomers (first round). General performance of the new descriptors in this QSPR studies is evaluated with regard to the well-known sets of 2D/3D MDs. From the analysis, we can conclude that the non-stochastic and stochastic bond-based linear indices have an overall good modeling capability proving their usefulness in QSPR studies. Later, the novel bond-level MDs are also used for the description and prediction of the boiling point of 28 alkyl-alcohols (second round), and to the modeling of the specific rate constant (log k), partition coefficient (log P), as well as the antibacterial activity of 34 derivatives of 2-furylethylenes (third round). The comparison with other approaches (edge- and vertices-based connectivity indices, total and local spectral moments, and quantum chemical descriptors as well as E-state/biomolecular encounter parameters) exposes a good behavior of our method in this QSPR studies. Finally, the approach described in this study appears to be a very promising structural invariant, useful not only for QSPR studies but also for similarity
Introduction to zeolite theory and modelling
Santen, van R.A.; Graaf, van de B.; Smit, B.; Bekkum, van H.
2001-01-01
A review. Some of the recent advances in zeolite theory and modeling are present. In particular the current status of computational chem. in Bronsted acid zeolite catalysis, mol. dynamics simulations of mols. adsorbed in zeolites, and novel Monte Carlo technique are discussed to simulate the
Prospect Theory in the Heterogeneous Agent Model
Czech Academy of Sciences Publication Activity Database
Polach, J.; Kukačka, Jiří
(2018) ISSN 1860-711X R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional support: RVO:67985556 Keywords : Heterogeneous Agent Model * Prospect Theory * Behavioral finance * Stylized facts Subject RIV: AH - Economic s OBOR OECD: Finance Impact factor: 0.931, year: 2016 http://library.utia.cas.cz/separaty/2018/E/kukacka-0488438.pdf
Diagrammatic group theory in quark models
International Nuclear Information System (INIS)
Canning, G.P.
1977-05-01
A simple and systematic diagrammatic method is presented for calculating the numerical factors arising from group theory in quark models: dimensions, casimir invariants, vector coupling coefficients and especially recoupling coefficients. Some coefficients for the coupling of 3 quark objects are listed for SU(n) and SU(2n). (orig.) [de
Aligning Grammatical Theories and Language Processing Models
Lewis, Shevaun; Phillips, Colin
2015-01-01
We address two important questions about the relationship between theoretical linguistics and psycholinguistics. First, do grammatical theories and language processing models describe separate cognitive systems, or are they accounts of different aspects of the same system? We argue that most evidence is consistent with the one-system view. Second,…
Sawamura, Jitsuki; Morishita, Shigeru; Ishigooka, Jun
2014-05-07
Previously, we suggested prototypal models that describe some clinical states based on group postulates. Here, we demonstrate a group/category theory-like model for molecular/genetic biology as an alternative application of our previous model. Specifically, we focus on deoxyribonucleic acid (DNA) base sequences. We construct a wallpaper pattern based on a five-letter cruciform motif with letters C, A, T, G, and E. Whereas the first four letters represent the standard DNA bases, the fifth is introduced for ease in formulating group operations that reproduce insertions and deletions of DNA base sequences. A basic group Z5 = {r, u, d, l, n} of operations is defined for the wallpaper pattern, with which a sequence of points can be generated corresponding to changes of a base in a DNA sequence by following the orbit of a point of the pattern under operations in group Z5. Other manipulations of DNA sequence can be treated using a vector-like notation 'Dj' corresponding to a DNA sequence but based on the five-letter base set; also, 'Dj's are expressed graphically. Insertions and deletions of a series of letters 'E' are admitted to assist in describing DNA recombination. Likewise, a vector-like notation Rj can be constructed for sequences of ribonucleic acid (RNA). The wallpaper group B = {Z5×∞, ●} (an ∞-fold Cartesian product of Z5) acts on Dj (or Rj) yielding changes to Dj (or Rj) denoted by 'Dj◦B(j→k) = Dk' (or 'Rj◦B(j→k) = Rk'). Based on the operations of this group, two types of groups-a modulo 5 linear group and a rotational group over the Gaussian plane, acting on the five bases-are linked as parts of the wallpaper group for broader applications. As a result, changes, insertions/deletions and DNA (RNA) recombination (partial/total conversion) are described. As an exploratory study, a notation for the canonical "central dogma" via a category theory-like way is presented for future developments. Despite the large incompleteness of our
Modelling non-ignorable missing data mechanisms with item response theory models
Holman, Rebecca; Glas, Cornelis A.W.
2005-01-01
A model-based procedure for assessing the extent to which missing data can be ignored and handling non-ignorable missing data is presented. The procedure is based on item response theory modelling. As an example, the approach is worked out in detail in conjunction with item response data modelled
Modelling non-ignorable missing-data mechanisms with item response theory models
Holman, Rebecca; Glas, Cees A. W.
2005-01-01
A model-based procedure for assessing the extent to which missing data can be ignored and handling non-ignorable missing data is presented. The procedure is based on item response theory modelling. As an example, the approach is worked out in detail in conjunction with item response data modelled
Linking Complexity and Sustainability Theories: Implications for Modeling Sustainability Transitions
Directory of Open Access Journals (Sweden)
Camaren Peter
2014-03-01
Full Text Available In this paper, we deploy a complexity theory as the foundation for integration of different theoretical approaches to sustainability and develop a rationale for a complexity-based framework for modeling transitions to sustainability. We propose a framework based on a comparison of complex systems’ properties that characterize the different theories that deal with transitions to sustainability. We argue that adopting a complexity theory based approach for modeling transitions requires going beyond deterministic frameworks; by adopting a probabilistic, integrative, inclusive and adaptive approach that can support transitions. We also illustrate how this complexity-based modeling framework can be implemented; i.e., how it can be used to select modeling techniques that address particular properties of complex systems that we need to understand in order to model transitions to sustainability. In doing so, we establish a complexity-based approach towards modeling sustainability transitions that caters for the broad range of complex systems’ properties that are required to model transitions to sustainability.
Automated Physico-Chemical Cell Model Development through Information Theory
Energy Technology Data Exchange (ETDEWEB)
Peter J. Ortoleva
2005-11-29
The objective of this project was to develop predictive models of the chemical responses of microbial cells to variations in their surroundings. The application of these models is optimization of environmental remediation and energy-producing biotechnical processes.The principles on which our project is based are as follows: chemical thermodynamics and kinetics; automation of calibration through information theory; integration of multiplex data (e.g. cDNA microarrays, NMR, proteomics), cell modeling, and bifurcation theory to overcome cellular complexity; and the use of multiplex data and information theory to calibrate and run an incomplete model. In this report we review four papers summarizing key findings and a web-enabled, multiple module workflow we have implemented that consists of a set of interoperable systems biology computational modules.
Glass Durability Modeling, Activated Complex Theory (ACT)
International Nuclear Information System (INIS)
CAROL, JANTZEN
2005-01-01
atomic ratios is shown to represent the structural effects of the glass on the dissolution and the formation of activated complexes in the glass leached layer. This provides two different methods by which a linear glass durability model can be formulated. One based on the quasi- crystalline mineral species in a glass and one based on cation ratios in the glass: both are related to the activated complexes on the surface by the law of mass action. The former would allow a new Thermodynamic Hydration Energy Model to be developed based on the hydration of the quasi-crystalline mineral species if all the pertinent thermodynamic data were available. Since the pertinent thermodynamic data is not available, the quasi-crystalline mineral species and the activated complexes can be related to cation ratios in the glass by the law of mass action. The cation ratio model can, thus, be used by waste form producers to formulate durable glasses based on fundamental structural and activated complex theories. Moreover, glass durability model based on atomic ratios simplifies HLW glass process control in that the measured ratios of only a few waste components and glass formers can be used to predict complex HLW glass performance with a high degree of accuracy, e.g. an R 2 approximately 0.97
PhysarumSoft: An update based on rough set theory
Schumann, Andrew; Pancerz, Krzysztof
2017-07-01
PhysarumSoft is a software tool consisting of two modules developed for programming Physarum machines and simulating Physarum games, respectively. The paper briefly discusses what has been added since the last version released in 2015. New elements in both modules are based on rough set theory. Rough sets are used to model behaviour of Physarum machines and to describe strategy games.
Unifying ecology and macroevolution with individual-based theory
Rosindell, James; Harmon, Luke J.; Etienne, Rampal S.
A contemporary goal in both ecology and evolutionary biology is to develop theory that transcends the boundary between the two disciplines, to understand phenomena that cannot be explained by either field in isolation. This is challenging because macroevolution typically uses lineage-based models,
Kuiper, Rebecca M.; Nederhoff, Tim; Klugkist, Irene
2015-01-01
In this paper, the performance of six types of techniques for comparisons of means is examined. These six emerge from the distinction between the method employed (hypothesis testing, model selection using information criteria, or Bayesian model selection) and the set of hypotheses that is
Optimal velocity difference model for a car-following theory
International Nuclear Information System (INIS)
Peng, G.H.; Cai, X.H.; Liu, C.Q.; Cao, B.F.; Tuo, M.X.
2011-01-01
In this Letter, we present a new optimal velocity difference model for a car-following theory based on the full velocity difference model. The linear stability condition of the new model is obtained by using the linear stability theory. The unrealistically high deceleration does not appear in OVDM. Numerical simulation of traffic dynamics shows that the new model can avoid the disadvantage of negative velocity occurred at small sensitivity coefficient λ in full velocity difference model by adjusting the coefficient of the optimal velocity difference, which shows that collision can disappear in the improved model. -- Highlights: → A new optimal velocity difference car-following model is proposed. → The effects of the optimal velocity difference on the stability of traffic flow have been explored. → The starting and braking process were carried out through simulation. → The effects of the optimal velocity difference can avoid the disadvantage of negative velocity.
Advances in cognitive theory and therapy: the generic cognitive model.
Beck, Aaron T; Haigh, Emily A P
2014-01-01
For over 50 years, Beck's cognitive model has provided an evidence-based way to conceptualize and treat psychological disorders. The generic cognitive model represents a set of common principles that can be applied across the spectrum of psychological disorders. The updated theoretical model provides a framework for addressing significant questions regarding the phenomenology of disorders not explained in previous iterations of the original model. New additions to the theory include continuity of adaptive and maladaptive function, dual information processing, energizing of schemas, and attentional focus. The model includes a theory of modes, an organization of schemas relevant to expectancies, self-evaluations, rules, and memories. A description of the new theoretical model is followed by a presentation of the corresponding applied model, which provides a template for conceptualizing a specific disorder and formulating a case. The focus on beliefs differentiates disorders and provides a target for treatment. A variety of interventions are described.
Effective field theory and the quark model
International Nuclear Information System (INIS)
Durand, Loyal; Ha, Phuoc; Jaczko, Gregory
2001-01-01
We analyze the connections between the quark model (QM) and the description of hadrons in the low-momentum limit of heavy-baryon effective field theory in QCD. By using a three-flavor-index representation for the effective baryon fields, we show that the 'nonrelativistic' constituent QM for baryon masses and moments is completely equivalent through O(m s ) to a parametrization of the relativistic field theory in a general spin-flavor basis. The flavor and spin variables can be identified with those of effective valence quarks. Conversely, the spin-flavor description clarifies the structure and dynamical interpretation of the chiral expansion in effective field theory, and provides a direct connection between the field theory and the semirelativistic models for hadrons used in successful dynamical calculations. This allows dynamical information to be incorporated directly into the chiral expansion. We find, for example, that the striking success of the additive QM for baryon magnetic moments is a consequence of the relative smallness of the non-additive spin-dependent corrections
Topos models for physics and topos theory
International Nuclear Information System (INIS)
Wolters, Sander
2014-01-01
What is the role of topos theory in the topos models for quantum theory as used by Isham, Butterfield, Döring, Heunen, Landsman, Spitters, and others? In other words, what is the interplay between physical motivation for the models and the mathematical framework used in these models? Concretely, we show that the presheaf topos model of Butterfield, Isham, and Döring resembles classical physics when viewed from the internal language of the presheaf topos, similar to the copresheaf topos model of Heunen, Landsman, and Spitters. Both the presheaf and copresheaf models provide a “quantum logic” in the form of a complete Heyting algebra. Although these algebras are natural from a topos theoretic stance, we seek a physical interpretation for the logical operations. Finally, we investigate dynamics. In particular, we describe how an automorphism on the operator algebra induces a homeomorphism (or isomorphism of locales) on the associated state spaces of the topos models, and how elementary propositions and truth values transform under the action of this homeomorphism. Also with dynamics the focus is on the internal perspective of the topos
Baldrige Theory into Practice: A Generic Model
Arif, Mohammed
2007-01-01
Purpose: The education system globally has moved from a push-based or producer-centric system to a pull-based or customer centric system. Malcolm Baldrige Quality Award (MBQA) model happens to be one of the latest additions to the pull based models. The purpose of this paper is to develop a generic framework for MBQA that can be used by…
Prospects for advanced RF theory and modeling
International Nuclear Information System (INIS)
Batchelor, D. B.
1999-01-01
This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed. (c) 1999 American Institute of Physics
A Membrane Model from Implicit Elasticity Theory
Freed, A. D.; Liao, J.; Einstein, D. R.
2014-01-01
A Fungean solid is derived for membranous materials as a body defined by isotropic response functions whose mathematical structure is that of a Hookean solid where the elastic constants are replaced by functions of state derived from an implicit, thermodynamic, internal-energy function. The theory utilizes Biot’s (1939) definitions for stress and strain that, in 1-dimension, are the stress/strain measures adopted by Fung (1967) when he postulated what is now known as Fung’s law. Our Fungean membrane model is parameterized against a biaxial data set acquired from a porcine pleural membrane subjected to three, sequential, proportional, planar extensions. These data support an isotropic/deviatoric split in the stress and strain-rate hypothesized by our theory. These data also demonstrate that the material response is highly non-linear but, otherwise, mechanically isotropic. These data are described reasonably well by our otherwise simple, four-parameter, material model. PMID:24282079
Directory of Open Access Journals (Sweden)
Pessôa Filho P. A.
2004-01-01
Full Text Available Mixtures containing compounds that undergo hydrogen bonding show large deviations from ideal behavior. These deviations can be accounted for through chemical theory, according to which the formation of a hydrogen bond can be treated as a chemical reaction. This chemical equilibrium needs to be taken into account when applying stability criteria and carrying out phase equilibrium calculations. In this work, we illustrate the application of the stability criteria to establish the conditions under which a liquid-phase split may occur and the subsequent calculation of liquid-liquid equilibrium using a chemical-theory-modified Flory-Huggins equation to describe the non ideality of aqueous two-phase systems composed of poly(ethylene glycol and dextran. The model was found to be able to correlate ternary liquid-liquid diagrams reasonably well by simple adjustment of the polymer-polymer binary interaction parameter.
Attribution models and the Cooperative Game Theory
Cano Berlanga, Sebastian; Vilella, Cori
2017-01-01
The current paper studies the attribution model used by Google Analytics. Precisely, we use the Cooperative Game Theory to propose a fair distribution of the revenues among the considered channels, in order to facilitate the cooperation and to guarantee stability. We define a transferable utility convex cooperative game from the observed frequencies and we use the Shapley value to allocate the revenues among the di erent channels. Furthermore, we evaluate the impact of an advertising...
Theory-based explanation as intervention.
Weisman, Kara; Markman, Ellen M
2017-10-01
Cogent explanations are an indispensable means of providing new information and an essential component of effective education. Beyond this, we argue that there is tremendous untapped potential in using explanations to motivate behavior change. In this article we focus on health interventions. We review four case studies that used carefully tailored explanations to address gaps and misconceptions in people's intuitive theories, providing participants with a conceptual framework for understanding how and why some recommended behavior is an effective way of achieving a health goal. These case studies targeted a variety of health-promoting behaviors: (1) children washing their hands to prevent viral epidemics; (2) parents vaccinating their children to stem the resurgence of infectious diseases; (3) adults completing the full course of an antibiotic prescription to reduce antibiotic resistance; and (4) children eating a variety of healthy foods to improve unhealthy diets. Simply telling people to engage in these behaviors has been largely ineffective-if anything, concern about these issues is mounting. But in each case, teaching participants coherent explanatory frameworks for understanding health recommendations has shown great promise, with such theory-based explanations outperforming state-of-the-art interventions from national health authorities. We contrast theory-based explanations both with simply listing facts, information, and advice and with providing a full-blown educational curriculum, and argue for providing the minimum amount of information required to understand the causal link between a target behavior and a health outcome. We argue that such theory-based explanations lend people the motivation and confidence to act on their new understanding.
MODELS AND THE DYNAMICS OF THEORIES
Directory of Open Access Journals (Sweden)
Paulo Abrantes
2007-12-01
Full Text Available Abstract: This paper gives a historical overview of the ways various trends in the philosophy of science dealt with models and their relationship with the topics of heuristics and theoretical dynamics. First of all, N. Campbell’s account of analogies as components of scientific theories is presented. Next, the notion of ‘model’ in the reconstruction of the structure of scientific theories proposed by logical empiricists is examined. This overview finishes with M. Hesse’s attempts to develop Campbell’s early ideas in terms of an analogical inference. The final part of the paper points to contemporary developments on these issues which adopt a cognitivist perspective. It is indicated how discussions in the cognitive sciences might help to flesh out some of the insights philosophers of science had concerning the role models and analogies play in actual scientific theorizing. Key words: models, analogical reasoning, metaphors in science, the structure of scientific theories, theoretical dynamics, heuristics, scientific discovery.
Unifying ecology and macroevolution with individual-based theory.
Rosindell, James; Harmon, Luke J; Etienne, Rampal S
2015-05-01
A contemporary goal in both ecology and evolutionary biology is to develop theory that transcends the boundary between the two disciplines, to understand phenomena that cannot be explained by either field in isolation. This is challenging because macroevolution typically uses lineage-based models, whereas ecology often focuses on individual organisms. Here, we develop a new parsimonious individual-based theory by adding mild selection to the neutral theory of biodiversity. We show that this model generates realistic phylogenies showing a slowdown in diversification and also improves on the ecological predictions of neutral theory by explaining the occurrence of very common species. Moreover, we find the distribution of individual fitness changes over time, with average fitness increasing at a pace that depends positively on community size. Consequently, large communities tend to produce fitter species than smaller communities. These findings have broad implications beyond biodiversity theory, potentially impacting, for example, invasion biology and paleontology. © 2015 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.
An introduction to queueing theory modeling and analysis in applications
Bhat, U Narayan
2015-01-01
This introductory textbook is designed for a one-semester course on queueing theory that does not require a course on stochastic processes as a prerequisite. By integrating the necessary background on stochastic processes with the analysis of models, the work provides a sound foundational introduction to the modeling and analysis of queueing systems for a wide interdisciplinary audience of students in mathematics, statistics, and applied disciplines such as computer science, operations research, and engineering. This edition includes additional topics in methodology and applications. Key features: • An introductory chapter including a historical account of the growth of queueing theory in more than 100 years. • A modeling-based approach with emphasis on identification of models. • Rigorous treatment of the foundations of basic models commonly used in applications with appropriate references for advanced topics. • Applications in manufacturing and, computer and communication systems. • A chapter on ...
International Nuclear Information System (INIS)
Randjbar-Daemi, S.
1987-01-01
The propagation of closed bosonic strings interacting with background gravitational and dilaton fields is reviewed. The string is treated as a quantum field theory on a compact 2-dimensional manifold. The question is posed as to how the conditions for the vanishing trace anomaly and the ensuing background field equations may depend on global features of the manifold. It is shown that to the leading order in σ-model perturbation theory the string loop effects do not modify the gravitational and the dilaton field equations. However for the purely bosonic strings new terms involving the modular parameter of the world sheet are induced by quantum effects which can be absorbed into a re-definition of the background fields. The authors also discuss some aspects of several regularization schemes such as dimensional, Pauli-Villars and the proper-time cut off in an appendix
Implications of Information Theory for Computational Modeling of Schizophrenia.
Silverstein, Steven M; Wibral, Michael; Phillips, William A
2017-10-01
Information theory provides a formal framework within which information processing and its disorders can be described. However, information theory has rarely been applied to modeling aspects of the cognitive neuroscience of schizophrenia. The goal of this article is to highlight the benefits of an approach based on information theory, including its recent extensions, for understanding several disrupted neural goal functions as well as related cognitive and symptomatic phenomena in schizophrenia. We begin by demonstrating that foundational concepts from information theory-such as Shannon information, entropy, data compression, block coding, and strategies to increase the signal-to-noise ratio-can be used to provide novel understandings of cognitive impairments in schizophrenia and metrics to evaluate their integrity. We then describe more recent developments in information theory, including the concepts of infomax, coherent infomax, and coding with synergy, to demonstrate how these can be used to develop computational models of schizophrenia-related failures in the tuning of sensory neurons, gain control, perceptual organization, thought organization, selective attention, context processing, predictive coding, and cognitive control. Throughout, we demonstrate how disordered mechanisms may explain both perceptual/cognitive changes and symptom emergence in schizophrenia. Finally, we demonstrate that there is consistency between some information-theoretic concepts and recent discoveries in neurobiology, especially involving the existence of distinct sites for the accumulation of driving input and contextual information prior to their interaction. This convergence can be used to guide future theory, experiment, and treatment development.
Information theory based approaches to cellular signaling.
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.
Theory of positive disintegration as a model of adolescent development.
Laycraft, Krystyna
2011-01-01
This article introduces a conceptual model of the adolescent development based on the theory of positive disintegration combined with theory of self-organization. Dabrowski's theory of positive disintegration, which was created almost a half century ago, still attracts psychologists' and educators' attention, and is extensively applied into studies of gifted and talented people. The positive disintegration is the mental development described by the process of transition from lower to higher levels of mental life and stimulated by tension, inner conflict, and anxiety. This process can be modeled by a sequence of patterns of organization (attractors) as a developmental potential (a control parameter) changes. Three levels of disintegration (unilevel disintegration, spontaneous multilevel disintegration, and organized multilevel disintegration) are analyzed in detail and it is proposed that they represent behaviour of early, middle and late periods of adolescence. In the discussion, recent research on the adolescent brain development is included.
Bridging Economic Theory Models and the Cointegrated Vector Autoregressive Model
DEFF Research Database (Denmark)
Møller, Niels Framroze
2008-01-01
Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity in the econo......Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity...... are related to expectations formation, market clearing, nominal rigidities, etc. Finally, the general-partial equilibrium distinction is analyzed....
Bridging Economic Theory Models and the Cointegrated Vector Autoregressive Model
DEFF Research Database (Denmark)
Møller, Niels Framroze
2008-01-01
Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity in the econo......Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity...... parameters of the CVAR are shown to be interpretable in terms of expectations formation, market clearing, nominal rigidities, etc. The general-partial equilibrium distinction is also discussed....
Quantum integrable models of field theory
International Nuclear Information System (INIS)
Faddeev, L.D.
1979-01-01
Fundamental features of the classical method of the inverse problem have been formulated in the form which is convenient for its quantum reformulation. Typical examples are studied which may help to formulate the quantum method of the inverse problem. Examples are considered for interaction with both attraction and repulsion at a final density. The sine-Gordon model and the XYZ model from the quantum theory of magnetics are examined in short. It is noted that all the achievements of the one-dimensional mathematical physics as applied to exactly solvable quantum models may be put to an extent within the framework of the quantum method of the inverse problem. Unsolved questions are enumerated and perspectives of applying the inverse problem method are shown
Theory and Model for Martensitic Transformations
DEFF Research Database (Denmark)
Lindgård, Per-Anker; Mouritsen, Ole G.
1986-01-01
Martensitic transformations are shown to be driven by the interplay between two fluctuating strain components. No soft mode is needed, but a central peak occurs representing the dynamics of strain clusters. A two-dimensional magnetic-analog model with the martensitic-transition symmetry is constr......Martensitic transformations are shown to be driven by the interplay between two fluctuating strain components. No soft mode is needed, but a central peak occurs representing the dynamics of strain clusters. A two-dimensional magnetic-analog model with the martensitic-transition symmetry...... is constructed and analyzed by computer simulation and by a theory which accounts for correlation effects. Dramatic precursor effects at the first-order transition are demonstrated. The model is also of relevance for surface reconstruction transitions....
Economic contract theory tests models of mutualism.
Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E
2010-09-07
Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.
Magnetic flux tube models in superstring theory
Russo, Jorge G
1996-01-01
Superstring models describing curved 4-dimensional magnetic flux tube backgrounds are exactly solvable in terms of free fields. We consider the simplest model of this type (corresponding to `Kaluza-Klein' Melvin background). Its 2d action has a flat but topologically non-trivial 10-dimensional target space (there is a mixing of angular coordinate of the 2-plane with an internal compact coordinate). We demonstrate that this theory has broken supersymmetry but is perturbatively stable if the radius R of the internal coordinate is larger than R_0=\\sqrt{2\\a'}. In the Green-Schwarz formulation the supersymmetry breaking is a consequence of the presence of a flat but non-trivial connection in the fermionic terms in the action. For R R/2\\a' there appear instabilities corresponding to tachyonic winding states. The torus partition function Z(q,R) is finite for R > R_0 (and vanishes for qR=2n, n=integer). At the special points qR=2n (2n+1) the model is equivalent to the free superstring theory compactified on a circle...
A matrix model from string field theory
Directory of Open Access Journals (Sweden)
Syoji Zeze
2016-09-01
Full Text Available We demonstrate that a Hermitian matrix model can be derived from level truncated open string field theory with Chan-Paton factors. The Hermitian matrix is coupled with a scalar and U(N vectors which are responsible for the D-brane at the tachyon vacuum. Effective potential for the scalar is evaluated both for finite and large N. Increase of potential height is observed in both cases. The large $N$ matrix integral is identified with a system of N ZZ branes and a ghost FZZT brane.
Conformal field theories, Coulomb gas picture and integrable models
International Nuclear Information System (INIS)
Zuber, J.B.
1988-01-01
The aim of the study is to present the links between some results of conformal field theory, the conventional Coulomb gas picture in statistical mechanics and the approach of integrable models. It is shown that families of conformal theories, related by the coset construction to the SU(2) Kac-Moody algebra, may be regarded as obtained from some free field, and modified by the coupling of its winding numbers to floating charges. This representation reflects the procedure of restriction of the corresponding integrable lattice models. The work may be generalized to models based on the coset construction with higher rank algebras. The corresponding integrable models are identified. In the conformal field description, generalized parafermions appear, and are coupled to free fields living on a higher-dimensional torus. The analysis is not as exhaustive as in the SU(2) case: all the various restrictions have not been identified, nor the modular invariants completely classified
An integrative, experience-based theory of attentional control.
Wilder, Matthew H; Mozer, Michael C; Wickens, Christopher D
2011-02-09
Although diverse, theories of visual attention generally share the notion that attention is controlled by some combination of three distinct strategies: (1) exogenous cuing from locally contrasting primitive visual features, such as abrupt onsets or color singletons (e.g., L. Itti, C. Koch, & E. Neiber, 1998), (2) endogenous gain modulation of exogenous activations, used to guide attention to task-relevant features (e.g., V. Navalpakkam & L. Itti, 2007; J. Wolfe, 1994, 2007), and (3) endogenous prediction of likely locations of interest, based on task and scene gist (e.g., A. Torralba, A. Oliva, M. Castelhano, & J. Henderson, 2006). However, little work has been done to synthesize these disparate theories. In this work, we propose a unifying conceptualization in which attention is controlled along two dimensions: the degree of task focus and the contextual scale of operation. Previously proposed strategies-and their combinations-can be viewed as instances of this one mechanism. Thus, this theory serves not as a replacement for existing models but as a means of bringing them into a coherent framework. We present an implementation of this theory and demonstrate its applicability to a wide range of attentional phenomena. The model accounts for key results in visual search with synthetic images and makes reasonable predictions for human eye movements in search tasks involving real-world images. In addition, the theory offers an unusual perspective on attention that places a fundamental emphasis on the role of experience and task-related knowledge.
Introduction to the theory of bases
Marti, Jürg T
1969-01-01
Since the publication of Banach's treatise on the theory of linear operators, the literature on the theory of bases in topological vector spaces has grown enormously. Much of this literature has for its origin a question raised in Banach's book, the question whether every sepa rable Banach space possesses a basis or not. The notion of a basis employed here is a generalization of that of a Hamel basis for a finite dimensional vector space. For a vector space X of infinite dimension, the concept of a basis is closely related to the convergence of the series which uniquely correspond to each point of X. Thus there are different types of bases for X, according to the topology imposed on X and the chosen type of convergence for the series. Although almost four decades have elapsed since Banach's query, the conjectured existence of a basis for every separable Banach space is not yet proved. On the other hand, no counter examples have been found to show the existence of a special Banach space having no basis. Howe...
On low rank classical groups in string theory, gauge theory and matrix models
International Nuclear Information System (INIS)
Intriligator, Ken; Kraus, Per; Ryzhov, Anton V.; Shigemori, Masaki; Vafa, Cumrun
2004-01-01
We consider N=1 supersymmetric U(N), SO(N), and Sp(N) gauge theories, with two-index tensor matter and added tree-level superpotential, for general breaking patterns of the gauge group. By considering the string theory realization and geometric transitions, we clarify when glueball superfields should be included and extremized, or rather set to zero; this issue arises for unbroken group factors of low rank. The string theory results, which are equivalent to those of the matrix model, refer to a particular UV completion of the gauge theory, which could differ from conventional gauge theory results by residual instanton effects. Often, however, these effects exhibit miraculous cancellations, and the string theory or matrix model results end up agreeing with standard gauge theory. In particular, these string theory considerations explain and remove some apparent discrepancies between gauge theories and matrix models in the literature
Theory, modeling, and integrated studies in the Arase (ERG) project
Seki, Kanako; Miyoshi, Yoshizumi; Ebihara, Yusuke; Katoh, Yuto; Amano, Takanobu; Saito, Shinji; Shoji, Masafumi; Nakamizo, Aoi; Keika, Kunihiro; Hori, Tomoaki; Nakano, Shin'ya; Watanabe, Shigeto; Kamiya, Kei; Takahashi, Naoko; Omura, Yoshiharu; Nose, Masahito; Fok, Mei-Ching; Tanaka, Takashi; Ieda, Akimasa; Yoshikawa, Akimasa
2018-02-01
Understanding of underlying mechanisms of drastic variations of the near-Earth space (geospace) is one of the current focuses of the magnetospheric physics. The science target of the geospace research project Exploration of energization and Radiation in Geospace (ERG) is to understand the geospace variations with a focus on the relativistic electron acceleration and loss processes. In order to achieve the goal, the ERG project consists of the three parts: the Arase (ERG) satellite, ground-based observations, and theory/modeling/integrated studies. The role of theory/modeling/integrated studies part is to promote relevant theoretical and simulation studies as well as integrated data analysis to combine different kinds of observations and modeling. Here we provide technical reports on simulation and empirical models related to the ERG project together with their roles in the integrated studies of dynamic geospace variations. The simulation and empirical models covered include the radial diffusion model of the radiation belt electrons, GEMSIS-RB and RBW models, CIMI model with global MHD simulation REPPU, GEMSIS-RC model, plasmasphere thermosphere model, self-consistent wave-particle interaction simulations (electron hybrid code and ion hybrid code), the ionospheric electric potential (GEMSIS-POT) model, and SuperDARN electric field models with data assimilation. ERG (Arase) science center tools to support integrated studies with various kinds of data are also briefly introduced.[Figure not available: see fulltext.
Ensemble method: Community detection based on game theory
Zhang, Xia; Xia, Zhengyou; Xu, Shengwu; Wang, J. D.
2014-08-01
Timely and cost-effective analytics over social network has emerged as a key ingredient for success in many businesses and government endeavors. Community detection is an active research area of relevance to analyze online social network. The problem of selecting a particular community detection algorithm is crucial if the aim is to unveil the community structure of a network. The choice of a given methodology could affect the outcome of the experiments because different algorithms have different advantages and depend on tuning specific parameters. In this paper, we propose a community division model based on the notion of game theory, which can combine advantages of previous algorithms effectively to get a better community classification result. By making experiments on some standard dataset, it verifies that our community detection model based on game theory is valid and better.
Mobile applications for weight management: theory-based content analysis.
Azar, Kristen M J; Lesser, Lenard I; Laing, Brian Y; Stephens, Janna; Aurora, Magi S; Burke, Lora E; Palaniappan, Latha P
2013-11-01
The use of smartphone applications (apps) to assist with weight management is increasingly prevalent, but the quality of these apps is not well characterized. The goal of the study was to evaluate diet/nutrition and anthropometric tracking apps based on incorporation of features consistent with theories of behavior change. A comparative, descriptive assessment was conducted of the top-rated free apps in the Health and Fitness category available in the iTunes App Store. Health and Fitness apps (N=200) were evaluated using predetermined inclusion/exclusion criteria and categorized based on commonality in functionality, features, and developer description. Four researchers then evaluated the two most popular apps in each category using two instruments: one based on traditional behavioral theory (score range: 0-100) and the other on the Fogg Behavioral Model (score range: 0-6). Data collection and analysis occurred in November 2012. Eligible apps (n=23) were divided into five categories: (1) diet tracking; (2) healthy cooking; (3) weight/anthropometric tracking; (4) grocery decision making; and (5) restaurant decision making. The mean behavioral theory score was 8.1 (SD=4.2); the mean persuasive technology score was 1.9 (SD=1.7). The top-rated app on both scales was Lose It! by Fitnow Inc. All apps received low overall scores for inclusion of behavioral theory-based strategies. © 2013 American Journal of Preventive Medicine.
Application of Chaos Theory to Psychological Models
Blackerby, Rae Fortunato
This dissertation shows that an alternative theoretical approach from physics--chaos theory--offers a viable basis for improved understanding of human beings and their behavior. Chaos theory provides achievable frameworks for potential identification, assessment, and adjustment of human behavior patterns. Most current psychological models fail to address the metaphysical conditions inherent in the human system, thus bringing deep errors to psychological practice and empirical research. Freudian, Jungian and behavioristic perspectives are inadequate psychological models because they assume, either implicitly or explicitly, that the human psychological system is a closed, linear system. On the other hand, Adlerian models that require open systems are likely to be empirically tenable. Logically, models will hold only if the model's assumptions hold. The innovative application of chaotic dynamics to psychological behavior is a promising theoretical development because the application asserts that human systems are open, nonlinear and self-organizing. Chaotic dynamics use nonlinear mathematical relationships among factors that influence human systems. This dissertation explores these mathematical relationships in the context of a sample model of moral behavior using simulated data. Mathematical equations with nonlinear feedback loops describe chaotic systems. Feedback loops govern the equations' value in subsequent calculation iterations. For example, changes in moral behavior are affected by an individual's own self-centeredness, family and community influences, and previous moral behavior choices that feed back to influence future choices. When applying these factors to the chaos equations, the model behaves like other chaotic systems. For example, changes in moral behavior fluctuate in regular patterns, as determined by the values of the individual, family and community factors. In some cases, these fluctuations converge to one value; in other cases, they diverge in
Directory of Open Access Journals (Sweden)
Abe D Hofman
Full Text Available We propose and test three statistical models for the analysis of children's responses to the balance scale task, a seminal task to study proportional reasoning. We use a latent class modelling approach to formulate a rule-based latent class model (RB LCM following from a rule-based perspective on proportional reasoning and a new statistical model, the Weighted Sum Model, following from an information-integration approach. Moreover, a hybrid LCM using item covariates is proposed, combining aspects of both a rule-based and information-integration perspective. These models are applied to two different datasets, a standard paper-and-pencil test dataset (N = 779, and a dataset collected within an online learning environment that included direct feedback, time-pressure, and a reward system (N = 808. For the paper-and-pencil dataset the RB LCM resulted in the best fit, whereas for the online dataset the hybrid LCM provided the best fit. The standard paper-and-pencil dataset yielded more evidence for distinct solution rules than the online data set in which quantitative item characteristics are more prominent in determining responses. These results shed new light on the discussion on sequential rule-based and information-integration perspectives of cognitive development.
Nano-resonator frequency response based on strain gradient theory
International Nuclear Information System (INIS)
Miandoab, Ehsan Maani; Yousefi-Koma, Aghil; Pishkenari, Hossein Nejat; Fathi, Mohammad
2014-01-01
This paper aims to explore the dynamic behaviour of a nano-resonator under ac and dc excitation using strain gradient theory. To achieve this goal, the partial differential equation of nano-beam vibration is first converted to an ordinary differential equation by the Galerkin projection method and the lumped model is derived. Lumped parameters of the nano-resonator, such as linear and nonlinear springs and damper coefficients, are compared with those of classical theory and it is demonstrated that beams with smaller thickness display greater deviation from classical parameters. Stable and unstable equilibrium points based on classic and non-classical theories are also compared. The results show that, regarding the applied dc voltage, the dynamic behaviours expected by classical and non-classical theories are significantly different, such that one theory predicts the un-deformed shape as the stable condition, while the other theory predicts that the beam will experience bi-stability. To obtain the frequency response of the nano-resonator, a general equation including cubic and quadratic nonlinearities in addition to parametric electrostatic excitation terms is derived, and the analytical solution is determined using a second-order multiple scales method. Based on frequency response analysis, the softening and hardening effects given by two theories are investigated and compared, and it is observed that neglecting the size effect can lead to two completely different predictions in the dynamic behaviour of the resonators. The findings of this article can be helpful in the design and characterization of the size-dependent dynamic behaviour of resonators on small scales. (paper)
PARFUME Theory and Model basis Report
Energy Technology Data Exchange (ETDEWEB)
Darrell L. Knudson; Gregory K Miller; G.K. Miller; D.A. Petti; J.T. Maki; D.L. Knudson
2009-09-01
The success of gas reactors depends upon the safety and quality of the coated particle fuel. The fuel performance modeling code PARFUME simulates the mechanical, thermal and physico-chemical behavior of fuel particles during irradiation. This report documents the theory and material properties behind vari¬ous capabilities of the code, which include: 1) various options for calculating CO production and fission product gas release, 2) an analytical solution for stresses in the coating layers that accounts for irradiation-induced creep and swelling of the pyrocarbon layers, 3) a thermal model that calculates a time-dependent temperature profile through a pebble bed sphere or a prismatic block core, as well as through the layers of each analyzed particle, 4) simulation of multi-dimensional particle behavior associated with cracking in the IPyC layer, partial debonding of the IPyC from the SiC, particle asphericity, and kernel migration (or amoeba effect), 5) two independent methods for determining particle failure probabilities, 6) a model for calculating release-to-birth (R/B) ratios of gaseous fission products that accounts for particle failures and uranium contamination in the fuel matrix, and 7) the evaluation of an accident condition, where a particle experiences a sudden change in temperature following a period of normal irradiation. The accident condi¬tion entails diffusion of fission products through the particle coating layers and through the fuel matrix to the coolant boundary. This document represents the initial version of the PARFUME Theory and Model Basis Report. More detailed descriptions will be provided in future revisions.
Theory-based practice in a major medical centre.
Alligood, Martha Raile
2011-11-01
This project was designed to improve care quality and nursing staff satisfaction. Nursing theory structures thought and action as demonstrated by evidence of improvement in complex health-care settings. Nursing administrators selected Modelling and Role-Modelling (MRM) for the theory-based practice goal in their strategic plan. An action research approach structured implementation of MRM in a 1-year consultation project in 2001-2002. Quality of health care improved according to national quality assessment ratings, as well as patient satisfaction and nurse satisfaction. Modelling and Role-Modelling demonstrated capacity to structure nursing thought and action in patient care in a major medical centre. Uniformity of patient care language was valued by nurses as well as by allied health providers who wished to learn the holistic MRM style of practice. The processes of MRM and action research contributed to project success. A positive health-care change project was carried out in a large medical centre with action research. Introducing MRM theory-based practice was a beneficial decision by nursing administration that improved care and nurse satisfaction. Attention to nursing practice stimulated career development among the nurses to pursue bachelors, masters, and doctoral degrees. © 2011 Blackwell Publishing Ltd.
Rule-based decision making model
International Nuclear Information System (INIS)
Sirola, Miki
1998-01-01
A rule-based decision making model is designed in G2 environment. A theoretical and methodological frame for the model is composed and motivated. The rule-based decision making model is based on object-oriented modelling, knowledge engineering and decision theory. The idea of safety objective tree is utilized. Advanced rule-based methodologies are applied. A general decision making model 'decision element' is constructed. The strategy planning of the decision element is based on e.g. value theory and utility theory. A hypothetical process model is built to give input data for the decision element. The basic principle of the object model in decision making is division in tasks. Probability models are used in characterizing component availabilities. Bayes' theorem is used to recalculate the probability figures when new information is got. The model includes simple learning features to save the solution path. A decision analytic interpretation is given to the decision making process. (author)
Stochastic linear programming models, theory, and computation
Kall, Peter
2011-01-01
This new edition of Stochastic Linear Programming: Models, Theory and Computation has been brought completely up to date, either dealing with or at least referring to new material on models and methods, including DEA with stochastic outputs modeled via constraints on special risk functions (generalizing chance constraints, ICC’s and CVaR constraints), material on Sharpe-ratio, and Asset Liability Management models involving CVaR in a multi-stage setup. To facilitate use as a text, exercises are included throughout the book, and web access is provided to a student version of the authors’ SLP-IOR software. Additionally, the authors have updated the Guide to Available Software, and they have included newer algorithms and modeling systems for SLP. The book is thus suitable as a text for advanced courses in stochastic optimization, and as a reference to the field. From Reviews of the First Edition: "The book presents a comprehensive study of stochastic linear optimization problems and their applications. … T...
Advances in heuristically based generalized perturbation theory
International Nuclear Information System (INIS)
Gandini, A.
1994-01-01
A distinctive feature of heuristically based generalized perturbation theory methodology consists in the systematic use of importance conservation concepts. As well known, this use leads to fundamental reciprocity relationship. Instead, the alternative variational and differential one approaches make a consistent use of the properties and adjoint functions. The equivalence between the importance and the adjoint functions have been demonstrated in important cases. There are some instances, however, in which the commonly known operator governing the adjoint function are not adequate. In this paper ways proposed to generalize this rules, as adopted with the heuristic generalized perturbation theory methodology, are illustrated. When applied to the neutron/nuclide field characterizing the core evolution in a power reactor system, in which also an intensive control variable (ρ) is defined, these rules leas to an orthogonality relationship connected to this same control variable. A set of ρ-mode eigenfunctions may be correspondingly defined and an extended concept of reactivity (generalizing that commonly associated with the multiplication factor) proposed as more directly indicative of the controllability of a critical reactor system. (author). 25 refs
Abisset-Chavanne, Emmanuelle; Duval, Jean Louis; Cueto, Elias; Chinesta, Francisco
2018-05-01
Traditionally, Simulation-Based Engineering Sciences (SBES) has relied on the use of static data inputs (model parameters, initial or boundary conditions, … obtained from adequate experiments) to perform simulations. A new paradigm in the field of Applied Sciences and Engineering has emerged in the last decade. Dynamic Data-Driven Application Systems [9, 10, 11, 12, 22] allow the linkage of simulation tools with measurement devices for real-time control of simulations and applications, entailing the ability to dynamically incorporate additional data into an executing application, and in reverse, the ability of an application to dynamically steer the measurement process. It is in that context that traditional "digital-twins" are giving raise to a new generation of goal-oriented data-driven application systems, also known as "hybrid-twins", embracing models based on physics and models exclusively based on data adequately collected and assimilated for filling the gap between usual model predictions and measurements. Within this framework new methodologies based on model learners, machine learning and kinetic goal-oriented design are defining a new paradigm in materials, processes and systems engineering.
Extending Theory-Based Quantitative Predictions to New Health Behaviors.
Brick, Leslie Ann D; Velicer, Wayne F; Redding, Colleen A; Rossi, Joseph S; Prochaska, James O
2016-04-01
Traditional null hypothesis significance testing suffers many limitations and is poorly adapted to theory testing. A proposed alternative approach, called Testing Theory-based Quantitative Predictions, uses effect size estimates and confidence intervals to directly test predictions based on theory. This paper replicates findings from previous smoking studies and extends the approach to diet and sun protection behaviors using baseline data from a Transtheoretical Model behavioral intervention (N = 5407). Effect size predictions were developed using two methods: (1) applying refined effect size estimates from previous smoking research or (2) using predictions developed by an expert panel. Thirteen of 15 predictions were confirmed for smoking. For diet, 7 of 14 predictions were confirmed using smoking predictions and 6 of 16 using expert panel predictions. For sun protection, 3 of 11 predictions were confirmed using smoking predictions and 5 of 19 using expert panel predictions. Expert panel predictions and smoking-based predictions poorly predicted effect sizes for diet and sun protection constructs. Future studies should aim to use previous empirical data to generate predictions whenever possible. The best results occur when there have been several iterations of predictions for a behavior, such as with smoking, demonstrating that expected values begin to converge on the population effect size. Overall, the study supports necessity in strengthening and revising theory with empirical data.
Properties of lattice gauge theory models at low temperatures
International Nuclear Information System (INIS)
Mack, G.
1980-01-01
The Z(N) theory of quark confinement is discussed and how fluctuations of Z(N) gauge fields may continue to be important in the continuum limit. Existence of a model in four dimensions is pointed out in which confinement of (scalar) quarks can be shown to persist in the continuum limit. This article is based on the author's Cargese lectures 1979. Some of its results are published here for the first time. (orig.) 891 HSI/orig. 892 MKO
Spherically symmetric star model in the gravitational gauge theory
Energy Technology Data Exchange (ETDEWEB)
Tsou, C [Peking Observatory, China; Ch' en, S; Ho, T; Kuo, H
1976-12-01
It is shown that a star model, which is black hole-free and singularity-free, can be obtained naturally in the gravitational gauge theory, provided the space-time is torsion-free and the matter is spinless. The conclusion in a sense shows that the discussions about the black hole and the singularity based on general relativity may not describe nature correctly.
International Nuclear Information System (INIS)
Kuang Qian-Wei; Liu Hong-Xia; Wang Shu-Long; Qin Shan-Shan; Wang Zhi-Lin
2011-01-01
After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k · p method. In the paper we calculate the accurate anisotropy valance bands and the splitting energy between light and heavy hole bands. The results show that the valance bands are highly distorted, and the anisotropy is more obvious. To obtain the density of states (DOS) effective mass, which is a very important parameter for device modeling, a DOS effective mass model of biaxial tensile strained Si is constructed based on the valance band calculation. This model can be directly used in the device model of metal—oxide semiconductor field effect transistor (MOSFET). It also a provides valuable reference for biaxial tensile strained silicon MOSFET design. (condensed matter: electronic structure, electrical, magnetic, and optical properties)
Physically based rendering from theory to implementation
Pharr, Matt
2010-01-01
"Physically Based Rendering, 2nd Edition" describes both the mathematical theory behind a modern photorealistic rendering system as well as its practical implementation. A method - known as 'literate programming'- combines human-readable documentation and source code into a single reference that is specifically designed to aid comprehension. The result is a stunning achievement in graphics education. Through the ideas and software in this book, you will learn to design and employ a full-featured rendering system for creating stunning imagery. This book features new sections on subsurface scattering, Metropolis light transport, precomputed light transport, multispectral rendering, and much more. It includes a companion site complete with source code for the rendering system described in the book, with support for Windows, OS X, and Linux. Code and text are tightly woven together through a unique indexing feature that lists each function, variable, and method on the page that they are first described.
Plasma balance equations based on orbit theory
International Nuclear Information System (INIS)
Lehnert, B.
1982-01-01
A set of plasma balance equations is proposed which is based on orbit theory and the particle distribution function, to provide means for theoretical analysis of a number of finite Larmor radius (FLR) phenomena without use of the Vlasov equation. Several important FLR effects originate from the inhomogeneity of an electric field in the plasma. The exact solution of a simple case shows that this inhomogeneity introduces fundamental changes in the physics of the particle motion. Thus, the periodic Larmor motion (gyration) is shifted in frequency and becomes elliptically polarized. Further, the non-periodic guiding-centre drift obtains additional components, part of which are accelerated such as to make the drift orbits intersect the equipotential surfaces of a static electric field. An attempt is finally made to classify the FLR effects, also with the purpose of identifying phenomena which have so far not been investigated. (author)
Directory of Open Access Journals (Sweden)
Lourdes Souto Anido
2016-11-01
. This paper proposes a Human resources management model based on fuzzy subsets theory to help reduce subjectivity that may be implied in these processes tools. This paper has been structured in three epigraphs. The first one presents an analysis of the Human Resources management Models used in Cuba. The second present the proposal of the Human Resources Management Model based on fuzzy subsets theory and finally on third epigraph the proposal is validated. The novelty of the proposed work lies in the integration of tools of the theory of fuzzy subsets in the key processes of Human Resources Management. Among the main contributions are: the application of the method of fuzzy to planning staff exponential smoothing, extrapolation of an allocation model solved through the Hungarian algorithm to staff training and building a system of fuzzy indicators for the evaluation of Human Resources Management. The proposal was validated through partial applications in companies in GECOMEX well as expert judgment.
Modeling and Optimization : Theory and Applications Conference
Terlaky, Tamás
2017-01-01
This volume contains a selection of contributions that were presented at the Modeling and Optimization: Theory and Applications Conference (MOPTA) held at Lehigh University in Bethlehem, Pennsylvania, USA on August 17-19, 2016. The conference brought together a diverse group of researchers and practitioners, working on both theoretical and practical aspects of continuous or discrete optimization. Topics presented included algorithms for solving convex, network, mixed-integer, nonlinear, and global optimization problems, and addressed the application of deterministic and stochastic optimization techniques in energy, finance, logistics, analytics, health, and other important fields. The contributions contained in this volume represent a sample of these topics and applications and illustrate the broad diversity of ideas discussed at the meeting.
Theory and modelling of nanocarbon phase stability.
Energy Technology Data Exchange (ETDEWEB)
Barnard, A. S.
2006-01-01
The transformation of nanodiamonds into carbon-onions (and vice versa) has been observed experimentally and has been modeled computationally at various levels of sophistication. Also, several analytical theories have been derived to describe the size, temperature and pressure dependence of this phase transition. However, in most cases a pure carbon-onion or nanodiamond is not the final product. More often than not an intermediary is formed, known as a bucky-diamond, with a diamond-like core encased in an onion-like shell. This has prompted a number of studies investigating the relative stability of nanodiamonds, bucky-diamonds, carbon-onions and fullerenes, in various size regimes. Presented here is a review outlining results of numerous theoretical studies examining the phase diagrams and phase stability of carbon nanoparticles, to clarify the complicated relationship between fullerenic and diamond structures at the nanoscale.
Modeling and Optimization : Theory and Applications Conference
Terlaky, Tamás
2015-01-01
This volume contains a selection of contributions that were presented at the Modeling and Optimization: Theory and Applications Conference (MOPTA) held at Lehigh University in Bethlehem, Pennsylvania, USA on August 13-15, 2014. The conference brought together a diverse group of researchers and practitioners, working on both theoretical and practical aspects of continuous or discrete optimization. Topics presented included algorithms for solving convex, network, mixed-integer, nonlinear, and global optimization problems, and addressed the application of deterministic and stochastic optimization techniques in energy, finance, logistics, analytics, healthcare, and other important fields. The contributions contained in this volume represent a sample of these topics and applications and illustrate the broad diversity of ideas discussed at the meeting.
Soliton excitations in polyacetylene and relativistic field theory models
International Nuclear Information System (INIS)
Campbell, D.K.; Bishop, A.R.; Los Alamos Scientific Lab., NM
1982-01-01
A continuum model of a Peierls-dimerized chain, as described generally by Brazovskii and discussed for the case of polyacetylene by Takayama, Lin-Liu and Maki (TLM), is considered. The continuum (Bogliubov-de Gennes) equations arising in this model of interacting electrons and phonons are shown to be equivalent to the static, semiclassical equations for a solvable model field theory of self-coupled fermions - the N = 2 Gross-Neveu model. Based on this equivalence we note the existence of soliton defect states in polyacetylene that are additional to, and qualitatively different from, the amplitude kinks commonly discussed. The new solutions do not have the topological stability of kinks but are essentially conventional strong-coupling polarons in the dimerized chain. They carry spin (1/2) and charge (+- e). In addition, we discuss further areas in which known field theory results may apply to a Peierls-dimerized chain, including relations between phenomenological PHI 4 and continuuum electron-phonon models, and the structure of the fully quantum versus mean field theories. (orig.)
Game Theory and its Relationship with Linear Programming Models ...
African Journals Online (AJOL)
Game Theory and its Relationship with Linear Programming Models. ... This paper shows that game theory and linear programming problem are closely related subjects since any computing method devised for ... AJOL African Journals Online.
Hosotani model in closed string theory
International Nuclear Information System (INIS)
Shiraishi, Kiyoshi.
1988-11-01
Hosotani mechanism in the closed string theory with current algebra symmetry is described by the (old covariant) operator method. We compare the gauge symmetry breaking mechanism in a string theory which has SU(2) symmetry with the one in an equivalent compactified closed string theory. We also investigate the difference between Hosotani mechanism and Higgs mechanism in closed string theories by calculation of a fourpoint amplitude of 'Higgs' bosons at tree level. (author)
The Properties of Model Selection when Retaining Theory Variables
DEFF Research Database (Denmark)
Hendry, David F.; Johansen, Søren
Economic theories are often fitted directly to data to avoid possible model selection biases. We show that embedding a theory model that specifies the correct set of m relevant exogenous variables, x{t}, within the larger set of m+k candidate variables, (x{t},w{t}), then selection over the second...... set by their statistical significance can be undertaken without affecting the estimator distribution of the theory parameters. This strategy returns the theory-parameter estimates when the theory is correct, yet protects against the theory being under-specified because some w{t} are relevant....
Measurement Models for Reasoned Action Theory.
Hennessy, Michael; Bleakley, Amy; Fishbein, Martin
2012-03-01
Quantitative researchers distinguish between causal and effect indicators. What are the analytic problems when both types of measures are present in a quantitative reasoned action analysis? To answer this question, we use data from a longitudinal study to estimate the association between two constructs central to reasoned action theory: behavioral beliefs and attitudes toward the behavior. The belief items are causal indicators that define a latent variable index while the attitude items are effect indicators that reflect the operation of a latent variable scale. We identify the issues when effect and causal indicators are present in a single analysis and conclude that both types of indicators can be incorporated in the analysis of data based on the reasoned action approach.
A Realizability Model for Impredicative Hoare Type Theory
DEFF Research Database (Denmark)
Petersen, Rasmus Lerchedal; Birkedal, Lars; Nanevski, Alexandar
2008-01-01
We present a denotational model of impredicative Hoare Type Theory, a very expressive dependent type theory in which one can specify and reason about mutable abstract data types. The model ensures soundness of the extension of Hoare Type Theory with impredicative polymorphism; makes the connections...... to separation logic clear, and provides a basis for investigation of further sound extensions of the theory, in particular equations between computations and types....
Irreducible integrable theories form tensor products of conformal models
International Nuclear Information System (INIS)
Mathur, S.D.; Warner, N.P.
1991-01-01
By using Toda field theories we show that there are perturbations of direct products of conformal theories that lead to irreducible integrable field theories. The same affine Toda theory can be truncated to different quantum integrable models for different choices of the charge at infinity and the coupling. The classification of integrable models that can be obtained in this fashion follows the classification of symmetric spaces of type G/H with rank H = rank G. (orig.)
Study on thermal wave based on the thermal mass theory
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The general law introduces a damped thermal wave equation.It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected,which indicates that the CV model only considers the temporal inertia of heat flux.Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory.For larger thermal perturbation,however,the physically impossible phenomenon pre-dicted by CV model,i.e.the negative temperature induced by the thermal wave superposition,is eliminated by the general heat conduction law,which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.
Study on thermal wave based on the thermal mass theory
Institute of Scientific and Technical Information of China (English)
HU RuiFeng; CAO BingYang
2009-01-01
The conservation equations for heat conduction are established based on the concept of thermal mass. We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass. The general law introduces a damped thermal wave equation. It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected, which indicates that the CV model only considers the temporal inertia of heat flux. Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory. For larger thermal perturbation, however, the physically impossible phenomenon pre-dicted by CV model, i.e. the negative temperature induced by the thermal wave superposition, is eliminated by the general heat conduction law, which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.
Profile-likelihood Confidence Intervals in Item Response Theory Models.
Chalmers, R Philip; Pek, Jolynn; Liu, Yang
2017-01-01
Confidence intervals (CIs) are fundamental inferential devices which quantify the sampling variability of parameter estimates. In item response theory, CIs have been primarily obtained from large-sample Wald-type approaches based on standard error estimates, derived from the observed or expected information matrix, after parameters have been estimated via maximum likelihood. An alternative approach to constructing CIs is to quantify sampling variability directly from the likelihood function with a technique known as profile-likelihood confidence intervals (PL CIs). In this article, we introduce PL CIs for item response theory models, compare PL CIs to classical large-sample Wald-type CIs, and demonstrate important distinctions among these CIs. CIs are then constructed for parameters directly estimated in the specified model and for transformed parameters which are often obtained post-estimation. Monte Carlo simulation results suggest that PL CIs perform consistently better than Wald-type CIs for both non-transformed and transformed parameters.
Chen, Xin; Sánchez-Arriaga, Gonzalo
2018-02-01
To model the sheath structure around an emissive probe with cylindrical geometry, the Orbital-Motion theory takes advantage of three conserved quantities (distribution function, transverse energy, and angular momentum) to transform the stationary Vlasov-Poisson system into a single integro-differential equation. For a stationary collisionless unmagnetized plasma, this equation describes self-consistently the probe characteristics. By solving such an equation numerically, parametric analyses for the current-voltage (IV) and floating-potential (FP) characteristics can be performed, which show that: (a) for strong emission, the space-charge effects increase with probe radius; (b) the probe can float at a positive potential relative to the plasma; (c) a smaller probe radius is preferred for the FP method to determine the plasma potential; (d) the work function of the emitting material and the plasma-ion properties do not influence the reliability of the floating-potential method. Analytical analysis demonstrates that the inflection point of an IV curve for non-emitting probes occurs at the plasma potential. The flat potential is not a self-consistent solution for emissive probes.
A model for hot electron phenomena: Theory and general results
International Nuclear Information System (INIS)
Carrillo, J.L.; Rodriquez, M.A.
1988-10-01
We propose a model for the description of the hot electron phenomena in semiconductors. Based on this model we are able to reproduce accurately the main characteristics observed in experiments of electric field transport, optical absorption, steady state photoluminescence and relaxation process. Our theory does not contain free nor adjustable parameters, it is very fast computerwise, and incorporates the main collision mechanisms including screening and phonon heating effects. Our description on a set of nonlinear rate equations in which the interactions are represented by coupling coefficients or effective frequencies. We calculate three coefficients from the characteristic constants and the band structure of the material. (author). 22 refs, 5 figs, 1 tab
A possibilistic uncertainty model in classical reliability theory
International Nuclear Information System (INIS)
De Cooman, G.; Capelle, B.
1994-01-01
The authors argue that a possibilistic uncertainty model can be used to represent linguistic uncertainty about the states of a system and of its components. Furthermore, the basic properties of the application of this model to classical reliability theory are studied. The notion of the possibilistic reliability of a system or a component is defined. Based on the concept of a binary structure function, the important notion of a possibilistic function is introduced. It allows to calculate the possibilistic reliability of a system in terms of the possibilistic reliabilities of its components
Theory and Circuit Model for Lossy Coaxial Transmission Line
Energy Technology Data Exchange (ETDEWEB)
Genoni, T. C.; Anderson, C. N.; Clark, R. E.; Gansz-Torres, J.; Rose, D. V.; Welch, Dale Robert
2017-04-01
The theory of signal propagation in lossy coaxial transmission lines is revisited and new approximate analytic formulas for the line impedance and attenuation are derived. The accuracy of these formulas from DC to 100 GHz is demonstrated by comparison to numerical solutions of the exact field equations. Based on this analysis, a new circuit model is described which accurately reproduces the line response over the entire frequency range. Circuit model calculations are in excellent agreement with the numerical and analytic results, and with finite-difference-time-domain simulations which resolve the skindepths of the conducting walls.
Institute of Scientific and Technical Information of China (English)
Yun Wang; Renhai Hua; Zongcheng Zhang
2011-01-01
Purpose-The purpose of this paper is to examine whether the futures volatility could attect the investor behavior and what trading strategy different investors could adopt when they meet different information conditions.Design/methodology/approach-This study introduces a two-period overlapping generation model (OLG) model into the future market and set the investor behavior model based on the future contract price,which can also be extended to complete and incomplete information.It provides the equilibrium solution and uses cuprum tick data in SHFE to conduct the empirical analysis.Findings-The two-period OLG model based on the future market is consistent with the practical situation;second,the sufficient information investors such as institutional adopt reversal trading patterns generally;last,the insufficient information investors such as individual investors adopt momentum trading patterns in general.Research limitations/implications-Investor trading behavior is always an important issue in the behavioral finance and market supervision,but the related research is scarce.Practical implications-The conclusion shows that the investors' behavior in Chinese future market is different from the Chinese stock market.Originality/value-This study empirically analyzes and verifies the different types of trading strategies investors could;investors such as institutional ones adopt reversal trading patterns generally;while investors such as individual investors adopt momentum trading patterns in general.
White, Kari; Garces, Isabel C; Bandura, Lisa; McGuire, Allison A; Scarinci, Isabel C
2012-01-01
Breast and cervical cancer are common among Latinas, but screening rates among foreign-born Latinas are relatively low. In this article we describe the design and implementation of a theory-based (PEN-3) outreach program to promote breast and cervical cancer screening to Latina immigrants, and evaluate the program's effectiveness. We used data from self-administered questionnaires completed at six annual outreach events to examine the sociodemographic characteristics of attendees and evaluate whether the program reached the priority population - foreign-born Latina immigrants with limited access to health care and screening services. To evaluate the program's effectiveness in connecting women to screening, we examined the proportion and characteristics of women who scheduled and attended Pap smear and mammography appointments. Among the 782 Latinas who attended the outreach program, 60% and 83% had not had a Pap smear or mammogram, respectively, in at least a year. Overall, 80% scheduled a Pap smear and 78% scheduled a mammogram. Women without insurance, who did not know where to get screening and had not been screened in the last year were more likely to schedule appointments (P < .05). Among women who scheduled appointments, 65% attended their Pap smear and 79% attended the mammogram. We did not identify significant differences in sociodemographic characteristics associated with appointment attendance. Using a theoretical approach to outreach design and implementation, it is possible to reach a substantial number of Latina immigrants and connect them to cancer screening services.
Treatment of adolescent sexual offenders: theory-based practice.
Sermabeikian, P; Martinez, D
1994-11-01
The treatment of adolescent sexual offenders (ASO) has its theoretical underpinnings in social learning theory. Although social learning theory has been frequently cited in literature, a comprehensive application of this theory, as applied to practice, has not been mapped out. The social learning and social cognitive theories of Bandura appear to be particularly relevant to the group treatment of this population. The application of these theories to practice, as demonstrated in a program model, is discussed as a means of demonstrating how theory-driven practice methods can be developed.
Ground reaction curve based upon block theory
International Nuclear Information System (INIS)
Yow, J.L. Jr.; Goodman, R.E.
1985-09-01
Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. Once a potentially unstable block is identified, the forces affecting it can be calculated to assess its stability. The normal and shear stresses on each block face before displacement are calculated using elastic theory and are modified in a nonlinear way by discontinuity deformations as the keyblock displaces. The stresses are summed into resultant forces to evaluate block stability. Since the resultant forces change with displacement, successive increments of block movement are examined to see whether the block ultimately becomes stable or fails. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were evaluated. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls blocks displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender
International Nuclear Information System (INIS)
Cooper, F.
1996-01-01
We review the assumptions and domain of applicability of Landau's Hydrodynamical Model. By considering two models of particle production, pair production from strong electric fields and particle production in the linear σ model, we demonstrate that many of Landau's ideas are verified in explicit field theory calculations
Directory of Open Access Journals (Sweden)
Qiang Shang
2016-08-01
Full Text Available Short-term traffic flow prediction is an important part of intelligent transportation systems research and applications. For further improving the accuracy of short-time traffic flow prediction, a novel hybrid prediction model (multivariate phase space reconstruction–combined kernel function-least squares support vector machine based on multivariate phase space reconstruction and combined kernel function-least squares support vector machine is proposed. The C-C method is used to determine the optimal time delay and the optimal embedding dimension of traffic variables’ (flow, speed, and occupancy time series for phase space reconstruction. The G-P method is selected to calculate the correlation dimension of attractor which is an important index for judging chaotic characteristics of the traffic variables’ series. The optimal input form of combined kernel function-least squares support vector machine model is determined by multivariate phase space reconstruction, and the model’s parameters are optimized by particle swarm optimization algorithm. Finally, case validation is carried out using the measured data of an expressway in Xiamen, China. The experimental results suggest that the new proposed model yields better predictions compared with similar models (combined kernel function-least squares support vector machine, multivariate phase space reconstruction–generalized kernel function-least squares support vector machine, and phase space reconstruction–combined kernel function-least squares support vector machine, which indicates that the new proposed model exhibits stronger prediction ability and robustness.
Towards a Semantic E-Learning Theory by Using a Modelling Approach
Yli-Luoma, Pertti V. J.; Naeve, Ambjorn
2006-01-01
In the present study, a semantic perspective on e-learning theory is advanced and a modelling approach is used. This modelling approach towards the new learning theory is based on the four SECI phases of knowledge conversion: Socialisation, Externalisation, Combination and Internalisation, introduced by Nonaka in 1994, and involving two levels of…
Staccini, Pascal; Joubert, Michel; Quaranta, Jean-François; Fieschi, Marius
2005-03-01
Today, the economic and regulatory environment, involving activity-based and prospective payment systems, healthcare quality and risk analysis, traceability of the acts performed and evaluation of care practices, accounts for the current interest in clinical and hospital information systems. The structured gathering of information relative to users' needs and system requirements is fundamental when installing such systems. This stage takes time and is generally misconstrued by caregivers and is of limited efficacy to analysts. We used a modelling technique designed for manufacturing processes (IDEF0/SADT). We enhanced the basic model of an activity with descriptors extracted from the Ishikawa cause-and-effect diagram (methods, men, materials, machines, and environment). We proposed an object data model of a process and its components, and programmed a web-based tool in an object-oriented environment. This tool makes it possible to extract the data dictionary of a given process from the description of its elements and to locate documents (procedures, recommendations, instructions) according to each activity or role. Aimed at structuring needs and storing information provided by directly involved teams regarding the workings of an institution (or at least part of it), the process-mapping approach has an important contribution to make in the analysis of clinical information systems.
International Nuclear Information System (INIS)
Gajnutdinov, R.Kh.
1983-01-01
Possibility is studied to build the nonrelativistic scattering theory on the base of the general physical principles: causality, superposition, and unitarity, making no use of the Schroedinger formalism. The suggested approach is shown to be more general than the nonrelativistic scattering theory based on the Schroedinger equation. The approach is applied to build a model ofthe scattering theory for a system which consists of heavy nonrelativistic particles and a light relativistic particle
Chaos Theory as a Model for Managing Issues and Crises.
Murphy, Priscilla
1996-01-01
Uses chaos theory to model public relations situations in which the salient feature is volatility of public perceptions. Discusses the premises of chaos theory and applies them to issues management, the evolution of interest groups, crises, and rumors. Concludes that chaos theory is useful as an analogy to structure image problems and to raise…
Catastrophe Theory: A Unified Model for Educational Change.
Cryer, Patricia; Elton, Lewis
1990-01-01
Catastrophe Theory and Herzberg's theory of motivation at work was used to create a model of change that unifies and extends Lewin's two separate stage and force field models. This new model is used to analyze the behavior of academics as they adapt to the changing university environment. (Author/MLW)
Building Better Ecological Machines: Complexity Theory and Alternative Economic Models
Directory of Open Access Journals (Sweden)
Jess Bier
2016-12-01
Full Text Available Computer models of the economy are regularly used to predict economic phenomena and set financial policy. However, the conventional macroeconomic models are currently being reimagined after they failed to foresee the current economic crisis, the outlines of which began to be understood only in 2007-2008. In this article we analyze the most prominent of this reimagining: Agent-Based models (ABMs. ABMs are an influential alternative to standard economic models, and they are one focus of complexity theory, a discipline that is a more open successor to the conventional chaos and fractal modeling of the 1990s. The modelers who create ABMs claim that their models depict markets as ecologies, and that they are more responsive than conventional models that depict markets as machines. We challenge this presentation, arguing instead that recent modeling efforts amount to the creation of models as ecological machines. Our paper aims to contribute to an understanding of the organizing metaphors of macroeconomic models, which we argue is relevant conceptually and politically, e.g., when models are used for regulatory purposes.
Reconstructing Constructivism: Causal Models, Bayesian Learning Mechanisms, and the Theory Theory
Gopnik, Alison; Wellman, Henry M.
2012-01-01
We propose a new version of the "theory theory" grounded in the computational framework of probabilistic causal models and Bayesian learning. Probabilistic models allow a constructivist but rigorous and detailed approach to cognitive development. They also explain the learning of both more specific causal hypotheses and more abstract framework…
Oh, Young Sam
2017-02-01
In cancer care settings, family caregivers often experience negative or little communication with the health professionals, and this negative communication and limited health-related information causes psychological distress in family caregivers to cancer patients. The first aim of this research is to investigate the relationship between communication with health professionals and psychological distress in family caregivers. The second aim is to investigate the mediating effects of self-efficacy in this hypothetical model. A total of 1397 family caregivers were included in this research. A structural equation model was then applied, in order to examine the hypothesized model based on the stress-coping model. More negative communication with health professionals was associated with higher psychological distress. Self-efficacy in health information seeking significantly mediated the relationship between communication with health professionals and psychological distress. This study indicates that as a coping resource, self-efficacy in health information seeking, plays a significant role in reducing the effects of negative communication with health professionals on psychological distress in family caregivers. Copyright © 2016 Elsevier Inc. All rights reserved.
Theory and modeling of active brazing.
Energy Technology Data Exchange (ETDEWEB)
van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.
2013-09-01
Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.
Models, theory and applications in cooperative game theory
Hou, Dongshuang
2013-01-01
This thesis consists of an introductory chapter (Chapter 1) followed by nine research chapters (Chapters 2–10), each of which is written as a self-contained journal paper, except that all references are gathered at the end of the thesis. These nine chapters are based on the nine papers that are
Domain Theory, Its Models and Concepts
DEFF Research Database (Denmark)
Andreasen, Mogens Myrup; Howard, Thomas J.; Bruun, Hans Peter Lomholt
2014-01-01
Domain Theory is a systems approach for the analysis and synthesis of products. Its basic idea is to view a product as systems of activities, organs and parts and to define structure, elements, behaviour and function in these domains. The theory is a basis for a long line of research contribution...
Electrorheological fluids modeling and mathematical theory
Růžička, Michael
2000-01-01
This is the first book to present a model, based on rational mechanics of electrorheological fluids, that takes into account the complex interactions between the electromagnetic fields and the moving liquid. Several constitutive relations for the Cauchy stress tensor are discussed. The main part of the book is devoted to a mathematical investigation of a model possessing shear-dependent viscosities, proving the existence and uniqueness of weak and strong solutions for the steady and the unsteady case. The PDS systems investigated possess so-called non-standard growth conditions. Existence results for elliptic systems with non-standard growth conditions and with a nontrivial nonlinear r.h.s. and the first ever results for parabolic systems with a non-standard growth conditions are given for the first time. Written for advanced graduate students, as well as for researchers in the field, the discussion of both the modeling and the mathematics is self-contained.
Application of the evolution theory in modelling of innovation diffusion
Directory of Open Access Journals (Sweden)
Krstić Milan
2016-01-01
Full Text Available The theory of evolution has found numerous analogies and applications in other scientific disciplines apart from biology. In that sense, today the so-called 'memetic-evolution' has been widely accepted. Memes represent a complex adaptable system, where one 'meme' represents an evolutional cultural element, i.e. the smallest unit of information which can be identified and used in order to explain the evolution process. Among others, the field of innovations has proved itself to be a suitable area where the theory of evolution can also be successfully applied. In this work the authors have started from the assumption that it is also possible to apply the theory of evolution in the modelling of the process of innovation diffusion. Based on the conducted theoretical research, the authors conclude that the process of innovation diffusion in the interpretation of a 'meme' is actually the process of imitation of the 'meme' of innovation. Since during the process of their replication certain 'memes' show a bigger success compared to others, that eventually leads to their natural selection. For the survival of innovation 'memes', their manifestations are of key importance in the sense of their longevity, fruitfulness and faithful replicating. The results of the conducted research have categorically confirmed the assumption of the possibility of application of the evolution theory with the innovation diffusion with the help of innovation 'memes', which opens up the perspectives for some new researches on the subject.
Wu, Ya-Ke; Chu, Nain-Feng
2015-01-01
Overweight and obesity are serious public health and medical problems among children and adults worldwide. Behavioural change has been demonstrably contributory to weight management programs. Behavioural change-based weight loss programs require a theoretical framework. We will review the transtheoretical model and the organisational development theory in weight management. The transtheoretical model is a behaviour theory of individual level frequently used for weight management programs. The organisational development theory is a more complicated behaviour theory that applies to behavioural change on the system level. Both of these two theories have their respective strengths and weaknesses. In this manuscript, we try to introduce the transtheoretical model and the organisational development theory in the context of weight loss programs among population that are overweight or obese. Ultimately, we wish to present a new framework/strategy of weight management by integrating these two theories together. Copyright © 2015 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Drift-based Model for Power Scrape-off Width in Low-Gas-Puff H-mode Plasmas: Theory and Implications
Energy Technology Data Exchange (ETDEWEB)
Goldston, R., E-mail: rgoldston@pppl.gov [Princeton Plasma Physics Laboratory, Princeton (United States)
2012-09-15
Full text: A heuristic model for the plasma scrape-off width in low-gas-puff tokamak H-mode plasmas is introduced. {nabla}B and curvature drifts into the scrape-off layer (SOL) are balanced against near-sonic parallel flows out of the SOL, to the divertor plates. These assumptions result in an estimated SOL width of order the poloidal gyroradius. It is next assumed that anomalous perpendicular electron thermal diffusivity is the dominant source of heat flux across the separatrix, investing the SOL width, derived above, with heat from the main plasma. The separatrix temperature is then calculated based on a two-point model balancing power input to the SOL with Spitzer-Hiarm parallel thermal conduction losses to the divertor. This results in a heuristic closed-form prediction for the power scrape-off width that is in quantitative agreement both in absolute magnitude and in scaling with recent experimental data. The applicability of the Spitzer-Harm model to this regime can be questioned at the lowest densities, where the presence of a sheath can raise the divertor target electron temperature. A more general two-point model including a finite ratio of divertor target to upstream electron temperature shows only a 5% effect on the SOL width with target temperature f{sub T} = 75% of upstream, so this effect is likely negligible in experimentally relevant regimes. To achieve the near-sonic flows measured experimentally, and assumed in this model, sets requirements on the ratio of upstream to total SOL particle sources relative to the square-root of the ratio of target to upstream temperature. As a result very high recycling regimes may allow significantly wider power fluxes. The Pfisch-Schluter model for equilibrium flows has been modified to allow near-sonic flows, appropriate for gradient scale lengths of order the poloidal gyroradius. This results in a new quadrupole flow pattern that amplifies the usual P-S flows at the outer midplane, while reducing them at the inner
Application of the heuristically based GPT theory to termohydraulic problems
International Nuclear Information System (INIS)
Alvim, A.C.M.
1988-01-01
Application of heuristically based generalized perturbation theory (GPT) to the thermohydraulic (generally nonlinear) field is here illustrated. After a short description of the general methodology, the (linear) equations governing the importance function relevant to a generic multichannel problem are derived, within the physical model adopted in the COBRA IV-I Code. These equations are put in a form which should benefit of the calculational scheme of the original COBRA Code in the sense that only minor changes of it (mostly implying physical constants and source terms redefinitions) should be necessary for their solutions. (author) [pt
Developing a Theory-Based Simulation Educator Resource.
Thomas, Christine M; Sievers, Lisa D; Kellgren, Molly; Manning, Sara J; Rojas, Deborah E; Gamblian, Vivian C
2015-01-01
The NLN Leadership Development Program for Simulation Educators 2014 faculty development group identified a lack of a common language/terminology to outline the progression of expertise of simulation educators. The group analyzed Benner's novice-to-expert model and applied its levels of experience to simulation educator growth. It established common operational categories of faculty development and used them to organize resources that support progression toward expertise. The resulting theory-based Simulator Educator Toolkit outlines levels of ability and provides quality resources to meet the diverse needs of simulation educators and team members.
Design of structurally colored surfaces based on scalar diffraction theory
DEFF Research Database (Denmark)
Johansen, Villads Egede; Andkjær, Jacob Anders; Sigmund, Ole
2014-01-01
In this paper we investigate the possibility of controlling the color and appearance of surfaces simply by modifying the height profile of the surface on a nanoscale level. The applications for such methods are numerous: new design possibilities for high-end products, color engraving on any highly...... reflective surface, paint-free text and coloration, UV-resistant coloring, etc. In this initial study, the main focus is on finding a systematic way to obtain these results. For now the simulation and optimization is based on a simple scalar diffraction theory model. From the results, several design issues...
A Lie based 4-dimensional higher Chern-Simons theory
Zucchini, Roberto
2016-05-01
We present and study a model of 4-dimensional higher Chern-Simons theory, special Chern-Simons (SCS) theory, instances of which have appeared in the string literature, whose symmetry is encoded in a skeletal semistrict Lie 2-algebra constructed from a compact Lie group with non discrete center. The field content of SCS theory consists of a Lie valued 2-connection coupled to a background closed 3-form. SCS theory enjoys a large gauge and gauge for gauge symmetry organized in an infinite dimensional strict Lie 2-group. The partition function of SCS theory is simply related to that of a topological gauge theory localizing on flat connections with degree 3 second characteristic class determined by the background 3-form. Finally, SCS theory is related to a 3-dimensional special gauge theory whose 2-connection space has a natural symplectic structure with respect to which the 1-gauge transformation action is Hamiltonian, the 2-curvature map acting as moment map.
Huedo-Medina, Tania B; Shrestha, Roman; Copenhaver, Michael
2016-08-01
Although it is well established that people who use drugs (PWUDs, sus siglas en inglés) are characterized by significant neurocognitive impairment (NCI), there has been no examination of how NCI may impede one's ability to accrue the expected HIV prevention benefits stemming from an otherwise efficacious intervention. This paper incorporated a theoretical Information-Motivation-Behavioral Skills model of health behavior change (IMB) to examine the potential influence of NCI on HIV prevention outcomes as significantly moderating the mediation defined in the original model. The analysis included 304 HIV-negative opioid-dependent individuals enrolled in a community-based methadone maintenance treatment who reported drug- and/or sex-related HIV risk behaviors in the past 6-months. Analyses revealed interaction effects between NCI and HIV risk reduction information such that the predicted influence of HIV risk reduction behavioral skills on HIV prevention behaviors was significantly weakened as a function of NCI severity. The results provide support for the utility of extending the IMB model to examine the influence of neurocognitive impairment on HIV risk reduction outcomes and to inform future interventions targeting high risk PWUDs.
Refined pipe theory for mechanistic modeling of wood development.
Deckmyn, Gaby; Evans, Sam P; Randle, Tim J
2006-06-01
We present a mechanistic model of wood tissue development in response to changes in competition, management and climate. The model is based on a refinement of the pipe theory, where the constant ratio between sapwood and leaf area (pipe theory) is replaced by a ratio between pipe conductivity and leaf area. Simulated pipe conductivity changes with age, stand density and climate in response to changes in allocation or pipe radius, or both. The central equation of the model, which calculates the ratio of carbon (C) allocated to leaves and pipes, can be parameterized to describe the contrasting stem conductivity behavior of different tree species: from constant stem conductivity (functional homeostasis hypothesis) to height-related reduction in stem conductivity with age (hydraulic limitation hypothesis). The model simulates the daily growth of pipes (vessels or tracheids), fibers and parenchyma as well as vessel size and simulates the wood density profile and the earlywood to latewood ratio from these data. Initial runs indicate the model yields realistic seasonal changes in pipe radius (decreasing pipe radius from spring to autumn) and wood density, as well as realistic differences associated with the competitive status of trees (denser wood in suppressed trees).
The Standard Model is Natural as Magnetic Gauge Theory
DEFF Research Database (Denmark)
Sannino, Francesco
2011-01-01
matter. The absence of scalars in the electric theory indicates that the associated magnetic theory is free from quadratic divergences. Our novel solution to the Standard Model hierarchy problem leads also to a new insight on the mystery of the observed number of fundamental fermion generations......We suggest that the Standard Model can be viewed as the magnetic dual of a gauge theory featuring only fermionic matter content. We show this by first introducing a Pati-Salam like extension of the Standard Model and then relating it to a possible dual electric theory featuring only fermionic...
Directory of Open Access Journals (Sweden)
Kaner Eileen FS
2008-01-01
Full Text Available Abstract Background Psychological theories of behaviour may provide a framework to guide the design of interventions to change professional behaviour. Behaviour change interventions, designed using psychological theory and targeting important motivational beliefs, were experimentally evaluated for effects on the behavioural intention and simulated behaviour of GPs in the management of uncomplicated upper respiratory tract infection (URTI. Methods The design was a 2 × 2 factorial randomised controlled trial. A postal questionnaire was developed based on three theories of human behaviour: Theory of Planned Behaviour; Social Cognitive Theory and Operant Learning Theory. The beliefs and attitudes of GPs regarding the management of URTI without antibiotics and rates of prescribing on eight patient scenarios were measured at baseline and post-intervention. Two theory-based interventions, a "graded task" with "action planning" and a "persuasive communication", were incorporated into the post-intervention questionnaire. Trial groups were compared using co-variate analyses. Results Post-intervention questionnaires were returned for 340/397 (86% GPs who responded to the baseline survey. Each intervention had a significant effect on its targeted behavioural belief: compared to those not receiving the intervention GPs completing Intervention 1 reported stronger self-efficacy scores (Beta = 1.41, 95% CI: 0.64 to 2.25 and GPs completing Intervention 2 had more positive anticipated consequences scores (Beta = 0.98, 95% CI = 0.46 to 1.98. Intervention 2 had a significant effect on intention (Beta = 0.90, 95% CI = 0.41 to 1.38 and simulated behaviour (Beta = 0.47, 95% CI = 0.19 to 0.74. Conclusion GPs' intended management of URTI was significantly influenced by their confidence in their ability to manage URTI without antibiotics and the consequences they anticipated as a result of doing so. Two targeted behaviour change interventions differentially affected
Hrisos, Susan; Eccles, Martin; Johnston, Marie; Francis, Jill; Kaner, Eileen FS; Steen, Nick; Grimshaw, Jeremy
2008-01-01
Background Psychological theories of behaviour may provide a framework to guide the design of interventions to change professional behaviour. Behaviour change interventions, designed using psychological theory and targeting important motivational beliefs, were experimentally evaluated for effects on the behavioural intention and simulated behaviour of GPs in the management of uncomplicated upper respiratory tract infection (URTI). Methods The design was a 2 × 2 factorial randomised controlled trial. A postal questionnaire was developed based on three theories of human behaviour: Theory of Planned Behaviour; Social Cognitive Theory and Operant Learning Theory. The beliefs and attitudes of GPs regarding the management of URTI without antibiotics and rates of prescribing on eight patient scenarios were measured at baseline and post-intervention. Two theory-based interventions, a "graded task" with "action planning" and a "persuasive communication", were incorporated into the post-intervention questionnaire. Trial groups were compared using co-variate analyses. Results Post-intervention questionnaires were returned for 340/397 (86%) GPs who responded to the baseline survey. Each intervention had a significant effect on its targeted behavioural belief: compared to those not receiving the intervention GPs completing Intervention 1 reported stronger self-efficacy scores (Beta = 1.41, 95% CI: 0.64 to 2.25) and GPs completing Intervention 2 had more positive anticipated consequences scores (Beta = 0.98, 95% CI = 0.46 to 1.98). Intervention 2 had a significant effect on intention (Beta = 0.90, 95% CI = 0.41 to 1.38) and simulated behaviour (Beta = 0.47, 95% CI = 0.19 to 0.74). Conclusion GPs' intended management of URTI was significantly influenced by their confidence in their ability to manage URTI without antibiotics and the consequences they anticipated as a result of doing so. Two targeted behaviour change interventions differentially affected these beliefs. One
Chiral gauged Wess-Zumino-Witten theories and coset models in conformal field theory
International Nuclear Information System (INIS)
Chung, S.; Tye, S.H.
1993-01-01
The Wess-Zumino-Witten (WZW) theory has a global symmetry denoted by G L direct-product G R . In the standard gauged WZW theory, vector gauge fields (i.e., with vector gauge couplings) are in the adjoint representation of the subgroup H contained-in G. In this paper, we show that, in the conformal limit in two dimensions, there is a gauged WZW theory where the gauge fields are chiral and belong to the subgroups H L and H R where H L and H R can be different groups. In the special case where H L =H R , the theory is equivalent to vector gauged WZW theory. For general groups H L and H R , an examination of the correlation functions (or more precisely, conformal blocks) shows that the chiral gauged WZW theory is equivalent to (G/H L ) L direct-product(G/H R ) R coset models in conformal field theory
Spatial data modelling and maximum entropy theory
Czech Academy of Sciences Publication Activity Database
Klimešová, Dana; Ocelíková, E.
2005-01-01
Roč. 51, č. 2 (2005), s. 80-83 ISSN 0139-570X Institutional research plan: CEZ:AV0Z10750506 Keywords : spatial data classification * distribution function * error distribution Subject RIV: BD - Theory of Information
Electroweak theory and the Standard Model
CERN. Geneva; Giudice, Gian Francesco
2004-01-01
There is a natural splitting in four sectors of the theory of the ElectroWeak (EW) Interactions, at pretty different levels of development/test. Accordingly, the 5 lectures are organized as follows, with an eye to the future: Lecture 1: The basic structure of the theory; Lecture 2: The gauge sector; Lecture 3: The flavor sector; Lecture 4: The neutrino sector; Lecture 5: The EW symmetry breaking sector.
Statistical Learning Theory: Models, Concepts, and Results
von Luxburg, Ulrike; Schoelkopf, Bernhard
2008-01-01
Statistical learning theory provides the theoretical basis for many of today's machine learning algorithms. In this article we attempt to give a gentle, non-technical overview over the key ideas and insights of statistical learning theory. We target at a broad audience, not necessarily machine learning researchers. This paper can serve as a starting point for people who want to get an overview on the field before diving into technical details.
Morphing the Shell Model into an Effective Theory
International Nuclear Information System (INIS)
Haxton, W. C.; Song, C.-L.
2000-01-01
We describe a strategy for attacking the canonical nuclear structure problem--bound-state properties of a system of point nucleons interacting via a two-body potential--which involves an expansion in the number of particles scattering at high momenta, but is otherwise exact. The required self-consistent solutions of the Bloch-Horowitz equation for effective interactions and operators are obtained by an efficient Green's function method based on the Lanczos algorithm. We carry out this program for the simplest nuclei, d and 3 He , in order to explore the consequences of reformulating the shell model as a controlled effective theory. (c) 2000 The American Physical Society
Solid modeling and applications rapid prototyping, CAD and CAE theory
Um, Dugan
2016-01-01
The lessons in this fundamental text equip students with the theory of Computer Assisted Design (CAD), Computer Assisted Engineering (CAE), the essentials of Rapid Prototyping, as well as practical skills needed to apply this understanding in real world design and manufacturing settings. The book includes three main areas: CAD, CAE, and Rapid Prototyping, each enriched with numerous examples and exercises. In the CAD section, Professor Um outlines the basic concept of geometric modeling, Hermite and Bezier Spline curves theory, and 3-dimensional surface theories as well as rendering theory. The CAE section explores mesh generation theory, matrix notion for FEM, the stiffness method, and truss Equations. And in Rapid Prototyping, the author illustrates stereo lithographic theory and introduces popular modern RP technologies. Solid Modeling and Applications: Rapid Prototyping, CAD and CAE Theory is ideal for university students in various engineering disciplines as well as design engineers involved in product...
The logical foundations of scientific theories languages, structures, and models
Krause, Decio
2016-01-01
This book addresses the logical aspects of the foundations of scientific theories. Even though the relevance of formal methods in the study of scientific theories is now widely recognized and regaining prominence, the issues covered here are still not generally discussed in philosophy of science. The authors focus mainly on the role played by the underlying formal apparatuses employed in the construction of the models of scientific theories, relating the discussion with the so-called semantic approach to scientific theories. The book describes the role played by this metamathematical framework in three main aspects: considerations of formal languages employed to axiomatize scientific theories, the role of the axiomatic method itself, and the way set-theoretical structures, which play the role of the models of theories, are developed. The authors also discuss the differences and philosophical relevance of the two basic ways of aximoatizing a scientific theory, namely Patrick Suppes’ set theoretical predicate...
An approach to higher dimensional theories based on lattice gauge theory
International Nuclear Information System (INIS)
Murata, M.; So, H.
2004-01-01
A higher dimensional lattice space can be decomposed into a number of four-dimensional lattices called as layers. The higher dimensional gauge theory on the lattice can be interpreted as four-dimensional gauge theories on the multi-layer with interactions between neighboring layers. We propose the new possibility to realize the continuum limit of a five-dimensional theory based on the property of the phase diagram
Supersymmetry and String Theory: Beyond the Standard Model
International Nuclear Information System (INIS)
Rocek, Martin
2007-01-01
When I was asked to review Michael Dine's new book, 'Supersymmetry and String Theory', I was pleased to have a chance to read a book by such an established authority on how string theory might become testable. The book is most useful as a list of current topics of interest in modern theoretical physics. It gives a succinct summary of a huge variety of subjects, including the standard model, symmetry, Yang-Mills theory, quantization of gauge theories, the phenomenology of the standard model, the renormalization group, lattice gauge theory, effective field theories, anomalies, instantons, solitons, monopoles, dualities, technicolor, supersymmetry, the minimal supersymmetric standard model, dynamical supersymmetry breaking, extended supersymmetry, Seiberg-Witten theory, general relativity, cosmology, inflation, bosonic string theory, the superstring, the heterotic string, string compactifications, the quintic, string dualities, large extra dimensions, and, in the appendices, Goldstone's theorem, path integrals, and exact beta-functions in supersymmetric gauge theories. Its breadth is both its strength and its weakness: it is not (and could not possibly be) either a definitive reference for experts, where the details of thorny technical issues are carefully explored, or a textbook for graduate students, with detailed pedagogical expositions. As such, it complements rather than replaces the much narrower and more focussed String Theory I and II volumes by Polchinski, with their deep insights, as well the two older volumes by Green, Schwarz, and Witten, which develop string theory pedagogically. (book review)
Introduction to gauge theories and the Standard Model
de Wit, Bernard
1995-01-01
The conceptual basis of gauge theories is introduced to enable the construction of generic models.Spontaneous symmetry breaking is dicussed and its relevance for the renormalization of theories with massive vector field is explained. Subsequently a d standard model. When time permits we will address more practical questions that arise in the evaluation of quantum corrections.
A 'theory of everything'? [Extending the Standard Model
International Nuclear Information System (INIS)
Ross, G.G.
1993-01-01
The Standard Model provides us with an amazingly successful theory of the strong, weak and electromagnetic interactions. Despite this, many physicists believe it represents only a step towards understanding the ultimate ''theory of everything''. In this article we describe why the Standard Model is thought to be incomplete and some of the suggestions for its extension. (Author)
Neutron Star Models in Alternative Theories of Gravity
Manolidis, Dimitrios
We study the structure of neutron stars in a broad class of alternative theories of gravity. In particular, we focus on Scalar-Tensor theories and f(R) theories of gravity. We construct static and slowly rotating numerical star models for a set of equations of state, including a polytropic model and more realistic equations of state motivated by nuclear physics. Observable quantities such as masses, radii, etc are calculated for a set of parameters of the theories. Specifically for Scalar-Tensor theories, we also calculate the sensitivities of the mass and moment of inertia of the models to variations in the asymptotic value of the scalar field at infinity. These quantities enter post-Newtonian equations of motion and gravitational waveforms of two body systems that are used for gravitational-wave parameter estimation, in order to test these theories against observations. The construction of numerical models of neutron stars in f(R) theories of gravity has been difficult in the past. Using a new formalism by Jaime, Patino and Salgado we were able to construct models with high interior pressure, namely pc > rho c/3, both for constant density models and models with a polytropic equation of state. Thus, we have shown that earlier objections to f(R) theories on the basis of the inability to construct viable neutron star models are unfounded.
Generalized algebra-valued models of set theory
Löwe, B.; Tarafder, S.
2015-01-01
We generalize the construction of lattice-valued models of set theory due to Takeuti, Titani, Kozawa and Ozawa to a wider class of algebras and show that this yields a model of a paraconsistent logic that validates all axioms of the negation-free fragment of Zermelo-Fraenkel set theory.
A review of organizational buyer behaviour models and theories ...
African Journals Online (AJOL)
Over the years, models have been developed, and theories propounded, to explain the behavior of industrial buyers on the one hand and the nature of the dyadic relationship between organizational buyers and sellers on the other hand. This paper is an attempt at a review of the major models and theories in extant ...
The effect of education based on the Theory of Planned Behavior in smoking
Directory of Open Access Journals (Sweden)
Mahmoud Barfi
2018-03-01
Conclusion: According to the results, Education based on the theory of planned behavior has a positive impact on smoking behavior, Therefore, it is recommended that the above educational model is used to modify the behavior of smokers.
Models and theories of prescribing decisions: A review and suggested a new model.
Murshid, Mohsen Ali; Mohaidin, Zurina
2017-01-01
To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the 'persuasion theory - elaboration likelihood model', the stimuli-response marketing model', the 'agency theory', the theory of planned behaviour,' and 'social power theory,' in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research.
Continuing Bonds in Bereavement: An Attachment Theory Based Perspective
Field, Nigel P.; Gao, Beryl; Paderna, Lisa
2005-01-01
An attachment theory based perspective on the continuing bond to the deceased (CB) is proposed. The value of attachment theory in specifying the normative course of CB expression and in identifying adaptive versus maladaptive variants of CB expression based on their deviation from this normative course is outlined. The role of individual…
Diffusion theory model for optimization calculations of cold neutron sources
International Nuclear Information System (INIS)
Azmy, Y.Y.
1987-01-01
Cold neutron sources are becoming increasingly important and common experimental facilities made available at many research reactors around the world due to the high utility of cold neutrons in scattering experiments. The authors describe a simple two-group diffusion model of an infinite slab LD 2 cold source. The simplicity of the model permits to obtain an analytical solution from which one can deduce the reason for the optimum thickness based solely on diffusion-type phenomena. Also, a second more sophisticated model is described and the results compared to a deterministic transport calculation. The good (particularly qualitative) agreement between the results suggests that diffusion theory methods can be used in parametric and optimization studies to avoid the generally more expensive transport calculations
Robust optimization based upon statistical theory.
Sobotta, B; Söhn, M; Alber, M
2010-08-01
Organ movement is still the biggest challenge in cancer treatment despite advances in online imaging. Due to the resulting geometric uncertainties, the delivered dose cannot be predicted precisely at treatment planning time. Consequently, all associated dose metrics (e.g., EUD and maxDose) are random variables with a patient-specific probability distribution. The method that the authors propose makes these distributions the basis of the optimization and evaluation process. The authors start from a model of motion derived from patient-specific imaging. On a multitude of geometry instances sampled from this model, a dose metric is evaluated. The resulting pdf of this dose metric is termed outcome distribution. The approach optimizes the shape of the outcome distribution based on its mean and variance. This is in contrast to the conventional optimization of a nominal value (e.g., PTV EUD) computed on a single geometry instance. The mean and variance allow for an estimate of the expected treatment outcome along with the residual uncertainty. Besides being applicable to the target, the proposed method also seamlessly includes the organs at risk (OARs). The likelihood that a given value of a metric is reached in the treatment is predicted quantitatively. This information reveals potential hazards that may occur during the course of the treatment, thus helping the expert to find the right balance between the risk of insufficient normal tissue sparing and the risk of insufficient tumor control. By feeding this information to the optimizer, outcome distributions can be obtained where the probability of exceeding a given OAR maximum and that of falling short of a given target goal can be minimized simultaneously. The method is applicable to any source of residual motion uncertainty in treatment delivery. Any model that quantifies organ movement and deformation in terms of probability distributions can be used as basis for the algorithm. Thus, it can generate dose
Theory of thermoluminescence gamma dose response: The unified interaction model
International Nuclear Information System (INIS)
Horowitz, Y.S.
2001-01-01
We describe the development of a comprehensive theory of thermoluminescence (TL) dose response, the unified interaction model (UNIM). The UNIM is based on both radiation absorption stage and recombination stage mechanisms and can describe dose response for heavy charged particles (in the framework of the extended track interaction model - ETIM) as well as for isotropically ionising gamma rays and electrons (in the framework of the TC/LC geminate recombination model) in a unified and self-consistent conceptual and mathematical formalism. A theory of optical absorption dose response is also incorporated in the UNIM to describe the radiation absorption stage. The UNIM is applied to the dose response supralinearity characteristics of LiF:Mg,Ti and is especially and uniquely successful in explaining the ionisation density dependence of the supralinearity of composite peak 5 in TLD-100. The UNIM is demonstrated to be capable of explaining either qualitatively or quantitatively all of the major features of TL dose response with many of the variable parameters of the model strongly constrained by ancilliary optical absorption and sensitisation measurements
The Birth of Model Theory Lowenheim's Theorem in the Frame of the Theory of Relatives
Badesa, Calixto
2008-01-01
Löwenheim's theorem reflects a critical point in the history of mathematical logic, for it marks the birth of model theory--that is, the part of logic that concerns the relationship between formal theories and their models. However, while the original proofs of other, comparably significant theorems are well understood, this is not the case with Löwenheim's theorem. For example, the very result that scholars attribute to Löwenheim today is not the one that Skolem--a logician raised in the algebraic tradition, like Löwenheim--appears to have attributed to him. In The Birth of Model Theory, Cali
Transitional clerkship: an experiential course based on workplace learning theory.
Chittenden, Eva H; Henry, Duncan; Saxena, Varun; Loeser, Helen; O'Sullivan, Patricia S
2009-07-01
Starting clerkships is anxiety provoking for medical students. To ease the transition from preclerkship to clerkship curricula, schools offer classroom-based courses which may not be the best model for preparing learners. Drawing from workplace learning theory, the authors developed a seven-day transitional clerkship (TC) in 2007 at the University of California, San Francisco School of Medicine in which students spent half of the course in the hospital, learning routines and logistics of the wards along with their roles and responsibilities as members of ward teams. Twice, they admitted and followed a patient into the next day as part of a shadow team that had no patient-care responsibilities. Dedicated preceptors gave feedback on oral presentations and patient write-ups. Satisfaction with the TC was higher than with the previous year's classroom-based course. TC students felt clearer about their roles and more confident in their abilities as third-year students compared with previous students. TC students continued to rate the transitional course highly after their first clinical rotation. Preceptors were enthusiastic about the course and expressed willingness to commit to future TC preceptorships. The transitional course models an approach to translating workplace learning theory into practice and demonstrates improved satisfaction, better understanding of roles, and increased confidence among new third-year students.
Doshmangir, P; Jahangiry, L; Farhangi, M A; Doshmangir, L; Faraji, L
2018-02-01
The prevalence of type 2 diabetes is rising rapidly around the world. A number of systematic reviews have provided evidence for the effectiveness of lifestyle interventions on diabetic patients. The effectiveness of theory- and model-based education-lifestyle interventions for diabetic patients are unclear. The systematic review and meta-analysis aimed to evaluate and quantify the impact of theory-based lifestyle interventions on type 2 diabetes. A literature search of authentic electronic resources including PubMed, Scopus, and Cochrane collaboration was performed to identify published papers between January 2002 and July 2016. The PICOs (participants, intervention, comparison, and outcomes) elements were used for the selection of studies to meet the inclusion and exclusion criteria. Mean differences and standard deviations of hemoglobin A1c (HbA1c [mmol/mol]) level in baseline and follow-up measures of studies in intervention and control groups were considered for data synthesis. A random-effects model was used for estimating pooled effect sizes. To investigate the source of heterogeneity, predefined subgroup analyses were performed using trial duration, baseline HbA1c (mmol/mol) level, and the age of participants. Meta-regression was performed to examine the contribution of trial duration, baseline HbA1c (mmol/mol) level, the age of participants, and mean differences of HbA1c (mmol/mol) level. The significant level was considered P HbA1c (mmol/mol) -5.35% (95% confidence interval = -6.3, -4.40; P HbA1c (mmol/mol) indices in patients with type 2 diabetes. Health education theories have been applied as a useful tool for lifestyle change among people with type 2 diabetes. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Non-linear σ-models and string theories
International Nuclear Information System (INIS)
Sen, A.
1986-10-01
The connection between σ-models and string theories is discussed, as well as how the σ-models can be used as tools to prove various results in string theories. Closed bosonic string theory in the light cone gauge is very briefly introduced. Then, closed bosonic string theory in the presence of massless background fields is discussed. The light cone gauge is used, and it is shown that in order to obtain a Lorentz invariant theory, the string theory in the presence of background fields must be described by a two-dimensional conformally invariant theory. The resulting constraints on the background fields are found to be the equations of motion of the string theory. The analysis is extended to the case of the heterotic string theory and the superstring theory in the presence of the massless background fields. It is then shown how to use these results to obtain nontrivial solutions to the string field equations. Another application of these results is shown, namely to prove that the effective cosmological constant after compactification vanishes as a consequence of the classical equations of motion of the string theory. 34 refs
Toric Methods in F-Theory Model Building
Directory of Open Access Journals (Sweden)
Johanna Knapp
2011-01-01
Full Text Available We discuss recent constructions of global F-theory GUT models and explain how to make use of toric geometry to do calculations within this framework. After introducing the basic properties of global F-theory GUTs, we give a self-contained review of toric geometry and introduce all the tools that are necessary to construct and analyze global F-theory models. We will explain how to systematically obtain a large class of compact Calabi-Yau fourfolds which can support F-theory GUTs by using the software package PALP.
The Operation Method of Smarter City Based on Ecological Theory
Fan, C.; Fan, H. Y.
2017-10-01
As the city and urbanization’s accelerated pace has caused galloping population, the urban framework is extending with increasingly complex social problems. The urban management tends to become complicated and the governance seems more difficult to pursue. exploring the urban management’s new model has attracted local governments’ urgent attention. tcombines the guiding ideology and that management’s practices based on ecological theory, explains the Smarter city Ecology Managementmodel’s formation, makes modern urban management’s comparative analysis and further defines the aforesaid management mode’s conceptual model. Based on the smarter city system theory’s ecological carrying capacity, the author uses mathematical model to prove the coordination relationship between the smarter city Ecology Managementmode’s subsystems, demonstrates that it can improve the urban management’s overall level, emphasizes smarter city management integrity, believing that urban system’s optimization is based on each subsystem being optimized, attaching the importance to elements, structure, and balance between each subsystem and between internal elements. Through the establishment of the smarter city Ecology Managementmodel’s conceptual model and theoretical argumentation, it provides a theoretical basis and technical guidance to that model’s innovation.
Quantum Link Models and Quantum Simulation of Gauge Theories
International Nuclear Information System (INIS)
Wiese, U.J.
2015-01-01
This lecture is about Quantum Link Models and Quantum Simulation of Gauge Theories. The lecture consists out of 4 parts. The first part gives a brief history of Computing and Pioneers of Quantum Computing and Quantum Simulations of Quantum Spin Systems are introduced. The 2nd lecture is about High-Temperature Superconductors versus QCD, Wilson’s Lattice QCD and Abelian Quantum Link Models. The 3rd lecture deals with Quantum Simulators for Abelian Lattice Gauge Theories and Non-Abelian Quantum Link Models. The last part of the lecture discusses Quantum Simulators mimicking ‘Nuclear’ physics and the continuum limit of D-Theorie models. (nowak)
SMD-based numerical stochastic perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Dalla Brida, Mattia [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano-Bicocca (Italy); Luescher, Martin [CERN, Theoretical Physics Department, Geneva (Switzerland); AEC, Institute for Theoretical Physics, University of Bern (Switzerland)
2017-05-15
The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously established and the use of higher-order symplectic integration schemes is shown to be highly profitable in this context. For illustration, the gradient-flow coupling in finite volume with Schroedinger functional boundary conditions is computed to two-loop (i.e. NNL) order in the SU(3) gauge theory. The scaling behaviour of the algorithm turns out to be rather favourable in this case, which allows the computations to be driven close to the continuum limit. (orig.)
SMD-based numerical stochastic perturbation theory
International Nuclear Information System (INIS)
Dalla Brida, Mattia; Luescher, Martin
2017-01-01
The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously established and the use of higher-order symplectic integration schemes is shown to be highly profitable in this context. For illustration, the gradient-flow coupling in finite volume with Schroedinger functional boundary conditions is computed to two-loop (i.e. NNL) order in the SU(3) gauge theory. The scaling behaviour of the algorithm turns out to be rather favourable in this case, which allows the computations to be driven close to the continuum limit. (orig.)
SMD-based numerical stochastic perturbation theory
Dalla Brida, Mattia; Lüscher, Martin
2017-05-01
The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously established and the use of higher-order symplectic integration schemes is shown to be highly profitable in this context. For illustration, the gradient-flow coupling in finite volume with Schrödinger functional boundary conditions is computed to two-loop (i.e. NNL) order in the SU(3) gauge theory. The scaling behaviour of the algorithm turns out to be rather favourable in this case, which allows the computations to be driven close to the continuum limit.
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.
A communication-theory based view on telemedical communication.
Schall, Thomas; Roeckelein, Wolfgang; Mohr, Markus; Kampshoff, Joerg; Lange, Tim; Nerlich, Michael
2003-01-01
Communication theory based analysis sheds new light on the use of health telematics. This analysis of structures in electronic medical communication shows communicative structures with special features. Current and evolving telemedical applications are analyzed. The methodology of communicational theory (focusing on linguistic pragmatics) is used to compare it with its conventional counterpart. The semiotic model, the roles of partners, the respective message and their relation are discussed. Channels, sender, addressee, and other structural roles are analyzed for different types of electronic medical communication. The communicative processes are shown as mutual, rational action towards a common goal. The types of communication/texts are analyzed in general. Furthermore the basic communicative structures of medical education via internet are presented with their special features. The analysis shows that electronic medical communication has special features compared to everyday communication: A third participant role often is involved: the patient. Messages often are addressed to an unspecified partner or to an unspecified partner within a group. Addressing in this case is (at least partially) role-based. Communication and message often directly (rather than indirectly) influence actions of the participants. Communication often is heavily regulated including legal implications like liability, and more. The conclusion from the analysis is that the development of telemedical applications so far did not sufficiently take communicative structures into consideration. Based on these results recommendations for future developments of telemedical applications/services are given.
The empirical bases of the scientific theory
International Nuclear Information System (INIS)
Cook, A.
1996-01-01
This paper was written according to a speech given by the author at the French Academy of Sciences in Paris on November 14, 1994. In this educational paper, the author tries to explain the origins and limitations of the scientific theories. The aim of science is to allow the edification of a rational framework which situates the observations we can make about the world in which we live. These observations are determined by the human capacities and by the physical world itself. Thus, the structure of our theories is, up to a certain limit, imposed by the observation constraints: for example, the relationship between the time evolution equation in quantum mechanics and the definition of the atomic time standard, or between the restricted relativity and the observation of far away events using the electromagnetic radiation. A corollary is that several physical systems can be assimilated to the representation of abstract groups, and this is a possible explanation of mathematics power in scientific theories. However, the group representation is not suitable for all natural systems, such as those referring to a chaotic dynamics. In this case, and in others in physics and biology, questions exist which cannot be answered by the simple study of the natural world
Market Mechanism Design for Renewable Energy based on Risk Theory
Yang, Wu; Bo, Wang; Jichun, Liu; Wenjiao, Zai; Pingliang, Zeng; Haobo, Shi
2018-02-01
Generation trading between renewable energy and thermal power is an efficient market means for transforming supply structure of electric power into sustainable development pattern. But the trading is hampered by the output fluctuations of renewable energy and the cost differences between renewable energy and thermal power at present. In this paper, the external environmental cost (EEC) is defined and the EEC is introduced into the generation cost. At same time, the incentive functions of renewable energy and low-emission thermal power are designed, which are decreasing functions of EEC. On these bases, for the market risks caused by the random variability of EEC, the decision-making model of generation trading between renewable energy and thermal power is constructed according to the risk theory. The feasibility and effectiveness of the proposed model are verified by simulation results.
Advancing Models and Theories for Digital Behavior Change Interventions.
Hekler, Eric B; Michie, Susan; Pavel, Misha; Rivera, Daniel E; Collins, Linda M; Jimison, Holly B; Garnett, Claire; Parral, Skye; Spruijt-Metz, Donna
2016-11-01
To be suitable for informing digital behavior change interventions, theories and models of behavior change need to capture individual variation and changes over time. The aim of this paper is to provide recommendations for development of models and theories that are informed by, and can inform, digital behavior change interventions based on discussions by international experts, including behavioral, computer, and health scientists and engineers. The proposed framework stipulates the use of a state-space representation to define when, where, for whom, and in what state for that person, an intervention will produce a targeted effect. The "state" is that of the individual based on multiple variables that define the "space" when a mechanism of action may produce the effect. A state-space representation can be used to help guide theorizing and identify crossdisciplinary methodologic strategies for improving measurement, experimental design, and analysis that can feasibly match the complexity of real-world behavior change via digital behavior change interventions. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Support vector machines optimization based theory, algorithms, and extensions
Deng, Naiyang; Zhang, Chunhua
2013-01-01
Support Vector Machines: Optimization Based Theory, Algorithms, and Extensions presents an accessible treatment of the two main components of support vector machines (SVMs)-classification problems and regression problems. The book emphasizes the close connection between optimization theory and SVMs since optimization is one of the pillars on which SVMs are built.The authors share insight on many of their research achievements. They give a precise interpretation of statistical leaning theory for C-support vector classification. They also discuss regularized twi
Graph-based linear scaling electronic structure theory
Energy Technology Data Exchange (ETDEWEB)
Niklasson, Anders M. N., E-mail: amn@lanl.gov; Negre, Christian F. A.; Cawkwell, Marc J.; Swart, Pieter J.; Germann, Timothy C.; Bock, Nicolas [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mniszewski, Susan M.; Mohd-Yusof, Jamal; Wall, Michael E.; Djidjev, Hristo [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rubensson, Emanuel H. [Division of Scientific Computing, Department of Information Technology, Uppsala University, Box 337, SE-751 05 Uppsala (Sweden)
2016-06-21
We show how graph theory can be combined with quantum theory to calculate the electronic structure of large complex systems. The graph formalism is general and applicable to a broad range of electronic structure methods and materials, including challenging systems such as biomolecules. The methodology combines well-controlled accuracy, low computational cost, and natural low-communication parallelism. This combination addresses substantial shortcomings of linear scaling electronic structure theory, in particular with respect to quantum-based molecular dynamics simulations.
FUSION SEGMENTATION METHOD BASED ON FUZZY THEORY FOR COLOR IMAGES
Directory of Open Access Journals (Sweden)
J. Zhao
2017-09-01
Full Text Available The image segmentation method based on two-dimensional histogram segments the image according to the thresholds of the intensity of the target pixel and the average intensity of its neighborhood. This method is essentially a hard-decision method. Due to the uncertainties when labeling the pixels around the threshold, the hard-decision method can easily get the wrong segmentation result. Therefore, a fusion segmentation method based on fuzzy theory is proposed in this paper. We use membership function to model the uncertainties on each color channel of the color image. Then, we segment the color image according to the fuzzy reasoning. The experiment results show that our proposed method can get better segmentation results both on the natural scene images and optical remote sensing images compared with the traditional thresholding method. The fusion method in this paper can provide new ideas for the information extraction of optical remote sensing images and polarization SAR images.
Non local theory of excitations applied to the Hubbard model
International Nuclear Information System (INIS)
Kakehashi, Y; Nakamura, T; Fulde, P
2010-01-01
We propose a nonlocal theory of single-particle excitations. It is based on an off-diagonal effective medium and the projection operator method for treating the retarded Green function. The theory determines the nonlocal effective medium matrix elements by requiring that they are consistent with those of the self-energy of the Green function. This arrows for a description of long-range intersite correlations with high resolution in momentum space. Numerical study for the half-filled Hubbard model on the simple cubic lattice demonstrates that the theory is applicable to the strong correlation regime as well as the intermediate regime of Coulomb interaction strength. Furthermore the results show that nonlocal excitations cause sub-bands in the strong Coulomb interaction regime due to strong antiferromagnetic correlations, decrease the quasi-particle peak on the Fermi level with increasing Coulomb interaction, and shift the critical Coulomb interaction U C2 for the divergence of effective mass towards higher energies at least by a factor of two as compared with that in the single-site approximation.
Trojanowicz, Karol; Wójcik, Wtodzimierz
2014-01-01
The description of a biofilm mathematical model application for dimensioning an aerated fixed bed biofilm reactor (ASFBBR) for petrochemical wastewater polishing is presented. A simple one-dimensional model of biofilm, developed by P Harremöes, was chosen for this purpose. The model was calibrated and verified under conditions of oil-refinery effluent. The results of ASFBBR dimensioning on the basis of the biofilm model were compared with the bioreactor dimensions determined by application of...
Multiagent model and mean field theory of complex auction dynamics
Chen, Qinghua; Huang, Zi-Gang; Wang, Yougui; Lai, Ying-Cheng
2015-09-01
Recent years have witnessed a growing interest in analyzing a variety of socio-economic phenomena using methods from statistical and nonlinear physics. We study a class of complex systems arising from economics, the lowest unique bid auction (LUBA) systems, which is a recently emerged class of online auction game systems. Through analyzing large, empirical data sets of LUBA, we identify a general feature of the bid price distribution: an inverted J-shaped function with exponential decay in the large bid price region. To account for the distribution, we propose a multi-agent model in which each agent bids stochastically in the field of winner’s attractiveness, and develop a theoretical framework to obtain analytic solutions of the model based on mean field analysis. The theory produces bid-price distributions that are in excellent agreement with those from the real data. Our model and theory capture the essential features of human behaviors in the competitive environment as exemplified by LUBA, and may provide significant quantitative insights into complex socio-economic phenomena.
Multiagent model and mean field theory of complex auction dynamics
International Nuclear Information System (INIS)
Chen, Qinghua; Wang, Yougui; Huang, Zi-Gang; Lai, Ying-Cheng
2015-01-01
Recent years have witnessed a growing interest in analyzing a variety of socio-economic phenomena using methods from statistical and nonlinear physics. We study a class of complex systems arising from economics, the lowest unique bid auction (LUBA) systems, which is a recently emerged class of online auction game systems. Through analyzing large, empirical data sets of LUBA, we identify a general feature of the bid price distribution: an inverted J-shaped function with exponential decay in the large bid price region. To account for the distribution, we propose a multi-agent model in which each agent bids stochastically in the field of winner’s attractiveness, and develop a theoretical framework to obtain analytic solutions of the model based on mean field analysis. The theory produces bid-price distributions that are in excellent agreement with those from the real data. Our model and theory capture the essential features of human behaviors in the competitive environment as exemplified by LUBA, and may provide significant quantitative insights into complex socio-economic phenomena. (paper)
Reconstructing constructivism: Causal models, Bayesian learning mechanisms and the theory theory
Gopnik, Alison; Wellman, Henry M.
2012-01-01
We propose a new version of the “theory theory” grounded in the computational framework of probabilistic causal models and Bayesian learning. Probabilistic models allow a constructivist but rigorous and detailed approach to cognitive development. They also explain the learning of both more specific causal hypotheses and more abstract framework theories. We outline the new theoretical ideas, explain the computational framework in an intuitive and non-technical way, and review an extensive but ...
The Self-Perception Theory vs. a Dynamic Learning Model
Swank, Otto H.
2006-01-01
Several economists have directed our attention to a finding in the social psychological literature that extrinsic motivation may undermine intrinsic motivation. The self-perception (SP) theory developed by Bem (1972) explains this finding. The crux of this theory is that people remember their past decisions and the extrinsic rewards they received, but they do not recall their intrinsic motives. In this paper I show that the SP theory can be modeled as a variant of a conventional dynamic learn...
A prediction method based on grey system theory in equipment condition based maintenance
International Nuclear Information System (INIS)
Yan, Shengyuan; Yan, Shengyuan; Zhang, Hongguo; Zhang, Zhijian; Peng, Minjun; Yang, Ming
2007-01-01
Grey prediction is a modeling method based on historical or present, known or indefinite information, which can be used for forecasting the development of the eigenvalues of the targeted equipment system and setting up the model by using less information. In this paper, the postulate of grey system theory, which includes the grey generating, the sorts of grey generating and the grey forecasting model, is introduced first. The concrete application process, which includes the grey prediction modeling, grey prediction, error calculation, equal dimension and new information approach, is introduced secondly. Application of a so-called 'Equal Dimension and New Information' (EDNI) technology in grey system theory is adopted in an application case, aiming at improving the accuracy of prediction without increasing the amount of calculation by replacing old data with new ones. The proposed method can provide a new way for solving the problem of eigenvalue data exploding in equal distance effectively, short time interval and real time prediction. The proposed method, which was based on historical or present, known or indefinite information, was verified by the vibration prediction of induced draft fan of a boiler of the Yantai Power Station in China, and the results show that the proposed method based on grey system theory is simple and provides a high accuracy in prediction. So, it is very useful and significant to the controlling and controllable management in safety production. (authors)
Criticism of the Classical Theory of Macroeconomic Modeling
Directory of Open Access Journals (Sweden)
Konstantin K. Kumehov
2015-01-01
Full Text Available Abstract: Current approaches and methods of modeling of macroeconomic systems do not allow to generate research ideas that could be used in applications. This is largely due to the fact that the dominant economic schools and research directions are building their theories on misconceptions about the economic system as object modeling, and have no common methodological approaches in the design of macroeconomic models. All of them are focused on building a model aimed at establishing equilibrium parameters of supply and demand, production and consumption. At the same time as the underlying factors are not considered resource potential and the needs of society in material and other benefits. In addition, there is no unity in the choice of elements and mechanisms of interaction between them. Not installed, what are the criteria to determine the elements of the model: whether it is the institutions, whether the industry is whether the population, or banks, or classes, etc. From the methodological point of view, the design of the model all the most well-known authors extrapolated to the new models of the past state or past events. As a result, every time the model is ready by the time the situation changes, the last parameters underlying the model are losing relevance, so at best, the researcher may have to interpret the events and parameters that are not feasible in the future. In this paper, based on analysis of the works of famous authors, belonging to different schools and areas revealed weaknesses of their proposed macroeconomic models that do not allow you to use them to solve applied problems of economic development. A fundamentally new approaches and methods by which it is possible the construction of macroeconomic models that take into account the theoretical and applied aspects of modeling, as well as formulated the basic methodological requirements.
Zaffran, Jeremie; Caspary Toroker, Maytal
2016-08-09
NiOOH has recently been used to catalyze water oxidation by way of electrochemical water splitting. Few experimental data are available to rationalize the successful catalytic capability of NiOOH. Thus, theory has a distinctive role for studying its properties. However, the unique layered structure of NiOOH is associated with the presence of essential dispersion forces within the lattice. Hence, the choice of an appropriate exchange-correlation functional within Density Functional Theory (DFT) is not straightforward. In this work, we will show that standard DFT is sufficient to evaluate the geometry, but DFT+U and hybrid functionals are required to calculate the oxidation states. Notably, the benefit of DFT with van der Waals correction is marginal. Furthermore, only hybrid functionals succeed in opening a bandgap, and such methods are necessary to study NiOOH electronic structure. In this work, we expect to give guidelines to theoreticians dealing with this material and to present a rational approach in the choice of the DFT method of calculation.
Theory and model use in social marketing health interventions.
Luca, Nadina Raluca; Suggs, L Suzanne
2013-01-01
The existing literature suggests that theories and models can serve as valuable frameworks for the design and evaluation of health interventions. However, evidence on the use of theories and models in social marketing interventions is sparse. The purpose of this systematic review is to identify to what extent papers about social marketing health interventions report using theory, which theories are most commonly used, and how theory was used. A systematic search was conducted for articles that reported social marketing interventions for the prevention or management of cancer, diabetes, heart disease, HIV, STDs, and tobacco use, and behaviors related to reproductive health, physical activity, nutrition, and smoking cessation. Articles were published in English, after 1990, reported an evaluation, and met the 6 social marketing benchmarks criteria (behavior change, consumer research, segmentation and targeting, exchange, competition and marketing mix). Twenty-four articles, describing 17 interventions, met the inclusion criteria. Of these 17 interventions, 8 reported using theory and 7 stated how it was used. The transtheoretical model/stages of change was used more often than other theories. Findings highlight an ongoing lack of use or underreporting of the use of theory in social marketing campaigns and reinforce the call to action for applying and reporting theory to guide and evaluate interventions.
H+3 WZNW model from Liouville field theory
International Nuclear Information System (INIS)
Hikida, Y.; Schomerus, V.
2007-06-01
There exists an intriguing relation between genus zero correlation functions in the H + 3 WZNW model and in Liouville field theory. This was found by Ribault and Teschner based in part on earlier ideas by Stoyanovsky. We provide a path integral derivation of the correspondence and then use our new approach to generalize the relation to surfaces of arbitrary genus g. In particular we determine the correlation functions of N primary fields in the WZNW model explicitly through Liouville correlators with N+2g-2 additional insertions of certain degenerate fields. The paper concludes with a list of interesting further extensions and a few comments on the relation to the geometric Langlands program. (orig.)
Measurement Models for Reasoned Action Theory
Hennessy, Michael; Bleakley, Amy; Fishbein, Martin
2012-01-01
Quantitative researchers distinguish between causal and effect indicators. What are the analytic problems when both types of measures are present in a quantitative reasoned action analysis? To answer this question, we use data from a longitudinal study to estimate the association between two constructs central to reasoned action theory: behavioral beliefs and attitudes toward the behavior. The belief items are causal indicators that define a latent variable index while the attitude items are ...
Structural reliability analysis under evidence theory using the active learning kriging model
Yang, Xufeng; Liu, Yongshou; Ma, Panke
2017-11-01
Structural reliability analysis under evidence theory is investigated. It is rigorously proved that a surrogate model providing only correct sign prediction of the performance function can meet the accuracy requirement of evidence-theory-based reliability analysis. Accordingly, a method based on the active learning kriging model which only correctly predicts the sign of the performance function is proposed. Interval Monte Carlo simulation and a modified optimization method based on Karush-Kuhn-Tucker conditions are introduced to make the method more efficient in estimating the bounds of failure probability based on the kriging model. Four examples are investigated to demonstrate the efficiency and accuracy of the proposed method.
MOTIVATING ENGLISH TEACHERS BASED ON THE BASIC NEEDS THEORY AND AN EXPECTANCY THEORY
Directory of Open Access Journals (Sweden)
Hidayatus Sholihah
2017-08-01
Full Text Available There are two main motivation theories. a hierarchy of basic needs theory, and an expectancy theory. In a Hyrarchy of basic needs theory, Maslow has stated that the basic needs as a main behaviour direction are structured into a hierarchy. There are five basic human needs. The first: Physiological needs such as: salary, bonus or working condition. The second: the safety needs, such as: safe job environment, job security or health cover. The third, social needs, such as union and team work. The next is self esteem, such as getting an award, medal, certificate or any other recognisition. Then the last is self actualization, for example is by providing an opportunity to share knowledge, skills and eprerience. The evaluation of this theory are: there is no spiritual needs as human basic needs is a main weakness of this theory. Then it is possible that different level of needs have to be satisfied in the same time, or not in hierarchy level or, not always have to be fulfilled in order. The next motivation theory is an Expectancy Theory. This theory is based on three main factors. The first factor is: English teachers will be motivated to work harder if they have a good perception to their own competences in accordance with their job. The second, individual motivation depends on the rewards given when they finish a particular job. Finally, it also depends on their regards to the rewards given from the job that they do. Expectancy theory is a good theory, however, it is not easy to be implemented because the principals should provide various types of reward to satisfy the expectation of their English teachers. Considering the strengths and weaknesses of these two theories, it is better to combine both of them in the practice to get more effective results.
Base Station Performance Model
Walsh, Barbara; Farrell, Ronan
2005-01-01
At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...
Task-Based Language Teaching and Expansive Learning Theory
Robertson, Margaret
2014-01-01
Task-Based Language Teaching (TBLT) has become increasingly recognized as an effective pedagogy, but its location in generalized sociocultural theories of learning has led to misunderstandings and criticism. The purpose of this article is to explain the congruence between TBLT and Expansive Learning Theory and the benefits of doing so. The merit…
A density functional theory-based chemical potential equalisation
Indian Academy of Sciences (India)
A chemical potential equalisation scheme is proposed for the calculation of these quantities and hence the dipole polarizability within the framework of density functional theory based linear response theory. The resulting polarizability is expressed in terms of the contributions from individual atoms in the molecule. A few ...
Internal Universes in Models of Homotopy Type Theory
DEFF Research Database (Denmark)
Licata, Daniel R.; Orton, Ian; Pitts, Andrew M.
2018-01-01
We show that universes of fibrations in various models of homotopy type theory have an essentially global character: they cannot be described in the internal language of the presheaf topos from which the model is constructed. We get around this problem by extending the internal language with a mo...... that the interval in cubical sets does indeed have. This leads to a completely internal development of models of homotopy type theory within what we call crisp type theory.......We show that universes of fibrations in various models of homotopy type theory have an essentially global character: they cannot be described in the internal language of the presheaf topos from which the model is constructed. We get around this problem by extending the internal language...
Theory, modeling, and simulation annual report, 1992
Energy Technology Data Exchange (ETDEWEB)
1993-05-01
This report briefly discusses research on the following topics: development of electronic structure methods; modeling molecular processes in clusters; modeling molecular processes in solution; modeling molecular processes in separations chemistry; modeling interfacial molecular processes; modeling molecular processes in the atmosphere; methods for periodic calculations on solids; chemistry and physics of minerals; graphical user interfaces for computational chemistry codes; visualization and analysis of molecular simulations; integrated computational chemistry environment; and benchmark computations.
Theories of conduct disorder: a causal modelling analysis
Krol, N.P.C.M.; Morton, J.; Bruyn, E.E.J. De
2004-01-01
Background: If a clinician has to make decisions on diagnosis and treatment, he or she is confronted with a variety of causal theories. In order to compare these theories a neutral terminology and notational system is needed. The Causal Modelling framework involving three levels of description –
Models of Regge behaviour in an asymptotically free theory
International Nuclear Information System (INIS)
Polkinghorne, J.C.
1976-01-01
Two simple Feynman integral models are presented which reproduce the features expected to be of physical importance in the Regge behaviour of asymptotically free theories. Analysis confirms the result, expected on general grounds, that phi 3 in six dimensions has an essential singularity at l=-1. The extension to gauge theories is discussed. (Auth.)
Learning Theory Foundations of Simulation-Based Mastery Learning.
McGaghie, William C; Harris, Ilene B
2018-06-01
Simulation-based mastery learning (SBML), like all education interventions, has learning theory foundations. Recognition and comprehension of SBML learning theory foundations are essential for thoughtful education program development, research, and scholarship. We begin with a description of SBML followed by a section on the importance of learning theory foundations to shape and direct SBML education and research. We then discuss three principal learning theory conceptual frameworks that are associated with SBML-behavioral, constructivist, social cognitive-and their contributions to SBML thought and practice. We then discuss how the three learning theory frameworks converge in the course of planning, conducting, and evaluating SBML education programs in the health professions. Convergence of these learning theory frameworks is illustrated by a description of an SBML education and research program in advanced cardiac life support. We conclude with a brief coda.
A spillover-based theory of credentialism
Chris Bidner
2014-01-01
I propose a model in which credentials, such as diplomas, are intrinsically valuable; a situation described as credentialism. The model overcomes an important criticism of signalling models by mechanically tying a worker’s wages to their productivity. A worker’s productivity is influenced by the skills of their coworkers, where such skills arise from an ability-augmenting investment that is made prior to matching with coworkers. A worker’s credentials allow them to demonstrate their investmen...
Brucker, Ludovic; Picard, Ghislain; Roy, Alexandre; Dupont, Florent; Fily, Michel; Royer, Alain
2014-01-01
Microwave radiometer observations have been used to retrieve snow depth and snow water equivalent on both land and sea ice, snow accumulation on ice sheets, melt events, snow temperature, and snow grain size. Modeling the microwave emission from snow and ice physical properties is crucial to improve the quality of these retrievals. It also is crucial to improve our understanding of the radiative transfer processes within the snow cover, and the snow properties most relevant in microwave remote sensing. Our objective is to present a recent microwave emission model and its validation. The model is named DMRT-ML (DMRT Multi-Layer), and is available at http:lgge.osug.frpicarddmrtml.
Tissue Acoustoelectric Effect Modeling From Solid Mechanics Theory.
Song, Xizi; Qin, Yexian; Xu, Yanbin; Ingram, Pier; Witte, Russell S; Dong, Feng
2017-10-01
The acoustoelectric (AE) effect is a basic physical phenomenon, which underlies the changes made in the conductivity of a medium by the application of focused ultrasound. Recently, based on the AE effect, several biomedical imaging techniques have been widely studied, such as ultrasound-modulated electrical impedance tomography and ultrasound current source density imaging. To further investigate the mechanism of the AE effect in tissue and to provide guidance for such techniques, we have modeled the tissue AE effect using the theory of solid mechanics. Both bulk compression and thermal expansion of tissue are considered and discussed. Computation simulation shows that the muscle AE effect result, conductivity change rate, is 3.26×10 -3 with 4.3-MPa peak pressure, satisfying the theoretical value. Bulk compression plays the main role for muscle AE effect, while thermal expansion makes almost no contribution to it. In addition, the AE signals of porcine muscle are measured at different focal positions. With the same magnitude order and the same change trend, the experiment result confirms that the simulation result is effective. Both simulation and experimental results validate that tissue AE effect modeling using solid mechanics theory is feasible, which is of significance for the further development of related biomedical imaging techniques.
An Evolutionary Game Theory Model of Spontaneous Brain Functioning.
Madeo, Dario; Talarico, Agostino; Pascual-Leone, Alvaro; Mocenni, Chiara; Santarnecchi, Emiliano
2017-11-22
Our brain is a complex system of interconnected regions spontaneously organized into distinct networks. The integration of information between and within these networks is a continuous process that can be observed even when the brain is at rest, i.e. not engaged in any particular task. Moreover, such spontaneous dynamics show predictive value over individual cognitive profile and constitute a potential marker in neurological and psychiatric conditions, making its understanding of fundamental importance in modern neuroscience. Here we present a theoretical and mathematical model based on an extension of evolutionary game theory on networks (EGN), able to capture brain's interregional dynamics by balancing emulative and non-emulative attitudes among brain regions. This results in the net behavior of nodes composing resting-state networks identified using functional magnetic resonance imaging (fMRI), determining their moment-to-moment level of activation and inhibition as expressed by positive and negative shifts in BOLD fMRI signal. By spontaneously generating low-frequency oscillatory behaviors, the EGN model is able to mimic functional connectivity dynamics, approximate fMRI time series on the basis of initial subset of available data, as well as simulate the impact of network lesions and provide evidence of compensation mechanisms across networks. Results suggest evolutionary game theory on networks as a new potential framework for the understanding of human brain network dynamics.
Extended Nambu models: Their relation to gauge theories
Escobar, C. A.; Urrutia, L. F.
2017-05-01
Yang-Mills theories supplemented by an additional coordinate constraint, which is solved and substituted in the original Lagrangian, provide examples of the so-called Nambu models, in the case where such constraints arise from spontaneous Lorentz symmetry breaking. Some explicit calculations have shown that, after additional conditions are imposed, Nambu models are capable of reproducing the original gauge theories, thus making Lorentz violation unobservable and allowing the interpretation of the corresponding massless gauge bosons as the Goldstone bosons arising from the spontaneous symmetry breaking. A natural question posed by this approach in the realm of gauge theories is to determine under which conditions the recovery of an arbitrary gauge theory from the corresponding Nambu model, defined by a general constraint over the coordinates, becomes possible. We refer to these theories as extended Nambu models (ENM) and emphasize the fact that the defining coordinate constraint is not treated as a standard gauge fixing term. At this level, the mechanism for generating the constraint is irrelevant and the case of spontaneous Lorentz symmetry breaking is taken only as a motivation, which naturally bring this problem under consideration. Using a nonperturbative Hamiltonian analysis we prove that the ENM yields the original gauge theory after we demand current conservation for all time, together with the imposition of the Gauss laws constraints as initial conditions upon the dynamics of the ENM. The Nambu models yielding electrodynamics, Yang-Mills theories and linearized gravity are particular examples of our general approach.
Linear control theory for gene network modeling.
Shin, Yong-Jun; Bleris, Leonidas
2010-09-16
Systems biology is an interdisciplinary field that aims at understanding complex interactions in cells. Here we demonstrate that linear control theory can provide valuable insight and practical tools for the characterization of complex biological networks. We provide the foundation for such analyses through the study of several case studies including cascade and parallel forms, feedback and feedforward loops. We reproduce experimental results and provide rational analysis of the observed behavior. We demonstrate that methods such as the transfer function (frequency domain) and linear state-space (time domain) can be used to predict reliably the properties and transient behavior of complex network topologies and point to specific design strategies for synthetic networks.
Polling models : from theory to traffic intersections
Boon, M.A.A.
2011-01-01
The subject of the present monograph is the study of polling models, which are queueing models consisting of multiple queues, cyclically attended by one server. Polling models originated in the late 1950s, but did not receive much attention until the 1980s when an abundance of new applications arose
Modeling the Pineapple Express phenomenon via Multivariate Extreme Value Theory
Weller, G.; Cooley, D. S.
2011-12-01
The pineapple express (PE) phenomenon is responsible for producing extreme winter precipitation events in the coastal and mountainous regions of the western United States. Because the PE phenomenon is also associated with warm temperatures, the heavy precipitation and associated snowmelt can cause destructive flooding. In order to study impacts, it is important that regional climate models from NARCCAP are able to reproduce extreme precipitation events produced by PE. We define a daily precipitation quantity which captures the spatial extent and intensity of precipitation events produced by the PE phenomenon. We then use statistical extreme value theory to model the tail dependence of this quantity as seen in an observational data set and each of the six NARCCAP regional models driven by NCEP reanalysis. We find that most NCEP-driven NARCCAP models do exhibit tail dependence between daily model output and observations. Furthermore, we find that not all extreme precipitation events are pineapple express events, as identified by Dettinger et al. (2011). The synoptic-scale atmospheric processes that drive extreme precipitation events produced by PE have only recently begun to be examined. Much of the current work has focused on pattern recognition, rather than quantitative analysis. We use daily mean sea-level pressure (MSLP) fields from NCEP to develop a "pineapple express index" for extreme precipitation, which exhibits tail dependence with our observed precipitation quantity for pineapple express events. We build a statistical model that connects daily precipitation output from the WRFG model, daily MSLP fields from NCEP, and daily observed precipitation in the western US. Finally, we use this model to simulate future observed precipitation based on WRFG output driven by the CCSM model, and our pineapple express index derived from future CCSM output. Our aim is to use this model to develop a better understanding of the frequency and intensity of extreme
A Recursive BDI-Agent Model for Theory of Mind and its Applications
Bosse, T.; Memon, Z.A.; Treur, J.
2011-01-01
This article discusses a formal belief, desire, intention (BDI)-based agent model for theory of mind (ToM). The model uses BDI concepts to describe the reasoning process of an agent that reasons about the reasoning process of another agent, which is also based on BDI concepts. We discuss three
Contribution to the study of conformal theories and integrable models
International Nuclear Information System (INIS)
Sochen, N.
1992-05-01
The purpose of this thesis is the 2-D physics study. The main tool is the conformal field theory with Kac-Moody and W algebra. This theory describes the 2-D models that have translation, rotation and dilatation symmetries, at their critical point. The expanded conformal theories describe models that have a larger symmetry than conformal symmetry. After a review of conformal theory methods, the author effects a detailed study of singular vector form in sl(2) affine algebra. With this important form, correlation functions can be calculated. The classical W algebra is studied and the relations between classical W algebra and quantum W algebra are specified. Bosonization method is presented and sl(2)/sl(2) topological model, studied. Partition function bosonization of different models is described. A program of rational theory classification is described linking rational conformal theories and spin integrable models, and interesting relations between Boltzmann weights of different models have been found. With these relations, the integrability of models by a direct calculation of their Boltzmann weights is proved
Using Activity Theory as a Base for Investigating Language Teacher ...
African Journals Online (AJOL)
Using Activity Theory as a Base for Investigating Language Teacher Education through Digital Technology. ... Log in or Register to get access to full text downloads. ... how the platform has created tensions, contradictions and transformations.
Towards a Theory-Based Framework for Assessing the ...
African Journals Online (AJOL)
The theory-based framework attempts to capture ESD's complexity in terms of the ... projects in teacher education institutions in Botswana, a brief description of the ..... How the 'four pillars of learning' relate to education for sustainable human.