From spinors to probability amplitudes of external and internal variables for spinning particles

Author(s):  
M. Božić
1991 ◽  
Vol 06 (05) ◽  
pp. 807-844 ◽  
Author(s):  
ROBERT MARNELIUS ◽  
ULF MÅRTENSSON

By means of a previously developed procedure for the derivation of manifestly Lorentz covariant models of spinning particles, we derive new classes of models in which the internal variables transform as Lorentz spinors. Models for massless and massive particles of arbitrary spin are given in which the internal variables are fermionic or bosonic spinors. Lagrangians and their local invariances are explicitly written down for all models.


2002 ◽  
Vol 16 (3) ◽  
pp. 129-149 ◽  
Author(s):  
Boris Kotchoubey

Abstract Most cognitive psychophysiological studies assume (1) that there is a chain of (partially overlapping) cognitive processes (processing stages, mechanisms, operators) leading from stimulus to response, and (2) that components of event-related brain potentials (ERPs) may be regarded as manifestations of these processing stages. What is usually discussed is which particular processing mechanisms are related to some particular component, but not whether such a relationship exists at all. Alternatively, from the point of view of noncognitive (e. g., “naturalistic”) theories of perception ERP components might be conceived of as correlates of extraction of the information from the experimental environment. In a series of experiments, the author attempted to separate these two accounts, i. e., internal variables like mental operations or cognitive parameters versus external variables like information content of stimulation. Whenever this separation could be performed, the latter factor proved to significantly affect ERP amplitudes, whereas the former did not. These data indicate that ERPs cannot be unequivocally linked to processing mechanisms postulated by cognitive models of perception. Therefore, they cannot be regarded as support for these models.


2020 ◽  
Vol 48 (3) ◽  
pp. 1-11
Author(s):  
Qiyi Lin ◽  
Nan Zhou ◽  
Hong Fu

We investigated the prevalence of Chinese children's imaginary companions (ICs) and the internal variables of IC types (personified object or invisible friend) and child–IC relationship qualities (egalitarian or hierarchical child–IC relationship). Participants were 266 children aged 4 to 6 years. Only in the 5-year-old group was the proportion of children with ICs significantly higher among girls than among boys, implying that the relationship between gender and IC was not consistent across age groups. Children from families in the highest annual income group engaged in more IC play than did children from families in the lowest annual income group, indicating a relationship between family socioeconomic environment and children's imaginary play. IC types were not associated with child–IC relationship qualities in any of the age groups, implying that these qualities may represent different dimensions of IC play as early as 4 years old.


2020 ◽  
Vol 32 (6) ◽  
pp. 1619-1627 ◽  
Author(s):  
Jüri Engelbrecht ◽  
Kert Tamm ◽  
Tanel Peets

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Paulina Lisiecka-Graca ◽  
Krzysztof Bzowski ◽  
Janusz Majta ◽  
Krzysztof Muszka

AbstractThe mechanical behaviours of microalloyed and low-carbon steels under strain reversal were modelled based on the average dislocation density taking into account its allocation between the cell walls and cell interiors. The proposed model reflects the effects of the dislocations displacement, generation of new dislocations and their annihilation during the metal-forming processes. The back stress is assumed as one of the internal variables. The value of the initial dislocation density was calculated using two different computational methods, i.e. the first one based on the dislocation density tensor and the second one based on the strain gradient model. The proposed methods of calculating the dislocation density were subjected to a comparative analysis. For the microstructural analysis, the high-resolution electron backscatter diffraction (EBSD) microscopy was utilized. The calculation results were compared with the results of forward/reverse torsion tests. As a result, good effectiveness of the applied computational methodology was demonstrated. Finally, the analysis of dislocation distributions as an effect of the strain path change was performed.


2021 ◽  
pp. 136700692110165
Author(s):  
Kevin Martillo Viner

Aims and objectives: This study analyzes the proclitic and enclitic positions of Spanish clitic se (e.g., ella se quería ir / ella quería irse ‘she wanted to go’) across two generations of Spanish speakers in New York City. In an effort to contribute to ongoing research aimed at better understanding Spanish in the US, the following questions are addressed. In syntactic environments that permit variation, does placement of Spanish se differ between the two generations? From the internal variables identified for this study (nonfinite verb type, finite verb, tense of finite verb, grammatical person, use of se, grammatical mood of finite verb, negation), which ones have a statistically significant effect on placement? From the external variables identified for this study (national origin, region, areal origins, sex, age, years in US, socioeconomic class, education, English skill, Spanish skill, general Spanish use), which ones have a statistically significant effect on placement? Design and data: This study is carried out within a variationist-sociolinguistic framework and the sample consists of 50 participants, 25 from the first generation (G1) and 25 from the second (G2). Analysis: Bivariate chi-square tests are performed in order to determine what internal and external variables constrain placement of the dependent variable (clitic se placement). Findings: Generation has a statistically significant effect on placement ( p = .016), wherein proclisis is more frequent amongst the G2 participants. These results corroborate previous research showing an overall preference for proclisis in both monolingual and bilingual/heritage speakers. Further, chi-square tests pinpoint five conditioning effects for G1 (nonfinite verb type, use of se, finite verb, years in US, and English skill), but only two for G2 (use of se and English skill). Originality and implications: The present study is the first to discover strong correlations between the proclitic position and the numerous internal and external variables quantitatively assessed. Future research is thus warranted.


Author(s):  
Bo Yin ◽  
Johannes Storm ◽  
Michael Kaliske

AbstractThe promising phase-field method has been intensively studied for crack approximation in brittle materials. The realistic representation of material degradation at a fully evolved crack is still one of the main challenges. Several energy split formulations have been postulated to describe the crack evolution physically. A recent approach based on the concept of representative crack elements (RCE) in Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) introduces a variational framework to derive the kinematically consistent material degradation. The realistic material degradation is further tested using the self-consistency condition, which is particularly compared to a discrete crack model. This work extends the brittle RCE phase-field modeling towards rate-dependent fracture evolution in a viscoelastic continuum. The novelty of this paper is taking internal variables due to viscoelasticity into account to determine the crack deformation state. Meanwhile, a transient extension from Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) is also considered. The model is derived thermodynamic-consistently and implemented into the FE framework. Several representative numerical examples are investigated, and consequently, the according findings and potential perspectives are discussed to close this paper.


2021 ◽  
Vol 13 (1) ◽  
pp. 430
Author(s):  
José Alberto Martínez-González ◽  
Eduardo Parra-López ◽  
Almudena Barrientos-Báez

This paper aims to analyze the external and internal drivers of young consumers’ intention to participate in the sharing economy in tourism. From previous findings, a causal model (PLS) is designed to generate an integrated, practical, and novel structural model that significantly predicts the intention to participate. The model, consisting of nine dimensions, includes consumers’ external and internal variables. Separately, these variables have all been considered relevant in the literature, though they have not been studied jointly before. The descriptive results show the excellent attitude and predisposition of young people toward the tourism sharing economy, which facilitates their participation. Through the model, the importance of all internal and external consumer variables in the formation of intention are proven; however, attitude and social norm are most notable among them. Trust is also a critical variable that serves as the link between internal and external variables. The study provides managers of sharing economy platforms with knowledge to encourage young consumers’ participation in a communication and market orientation context. The generational approach (Generation Z) used also allows the conclusions and implications to be transferred to other regions and sectors.


2020 ◽  
Vol 45 (3) ◽  
pp. 311-318
Author(s):  
Qiang Yang ◽  
Zhuofu Tao ◽  
Yaoru Liu

AbstractIn the kinetic rate laws of internal variables, it is usually assumed that the rates of internal variables depend on the conjugate forces of the internal variables and the state variables. The dependence on the conjugate force has been fully addressed around flow potential functions. The kinetic rate laws can be formulated with two potential functions, the free energy function and the flow potential function. The dependence on the state variables has not been well addressed. Motivated by the previous study on the asymptotic stability of the internal variable theory by J. R. Rice, the thermodynamic significance of the dependence on the state variables is addressed in this paper. It is shown in this paper that the kinetic rate laws can be formulated by one extended potential function defined in an extended state space if the rates of internal variables do not depend explicitly on the internal variables. The extended state space is spanned by the state variables and the rate of internal variables. Furthermore, if the rates of internal variables do not depend explicitly on state variables, an extended Gibbs equation can be established based on the extended potential function, from which all constitutive equations can be recovered. This work may be considered as a certain Lagrangian formulation of the internal variable theory.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1161-1167
Author(s):  
Marin Marin ◽  
Praveen Ailawalia ◽  
Ioan Tuns

Abstract In this paper, we obtain a generalization of the Gronwall’s inequality to cover the study of porous elastic media considering their internal state variables. Based on some estimations obtained in three auxiliary results, we use this form of the Gronwall’s inequality to prove the uniqueness of solution for the mixed initial-boundary value problem considered in this context. Thus, we can conclude that even if we take into account the internal variables, this fact does not affect the uniqueness result regarding the solution of the mixed initial-boundary value problem in this context.


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