A scale invariant covariance structure on jet space

DEFF Research Database (Denmark)

Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

2005-01-01

This paper considers scale invariance of statistical image models. We study statistical scale invariance of the covariance structure of jet space under scale space blurring and derive the necessary structure and conditions of the jet covariance matrix in order for it to be scale invariant. As par...

Measurement Invariance and the Five-Factor Model of Personality: Asian International and Euro American Cultural Groups.

Science.gov (United States)

Rollock, David; Lui, P Priscilla

2016-10-01

This study examined measurement invariance of the NEO Five-Factor Inventory (NEO-FFI), assessing the five-factor model (FFM) of personality among Euro American (N = 290) and Asian international (N = 301) students (47.8% women, Mage = 19.69 years). The full 60-item NEO-FFI data fit the expected five-factor structure for both groups using exploratory structural equation modeling, and achieved configural invariance. Only 37 items significantly loaded onto the FFM-theorized factors for both groups and demonstrated metric invariance. Threshold invariance was not supported with this reduced item set. Groups differed the most in the item-factor relationships for Extraversion and Agreeableness, as well as in response styles. Asian internationals were more likely to use midpoint responses than Euro Americans. While the FFM can characterize broad nomothetic patterns of personality traits, metric invariance with only the subset of NEO-FFI items identified limits direct group comparisons of correlation coefficients among personality domains and with other constructs, and of mean differences on personality domains. © The Author(s) 2015.

Childhood Trauma Questionnaire: factor structure, measurement invariance, and validity across emotional disorders

NARCIS (Netherlands)

Spinhoven, P.; Penninx, B.W.; Hickendorff, M.; van Hemert, A.M.; Bernstein, D.P.; Elzinga, B.M.

2014-01-01

To study the psychometric properties of the Childhood Trauma Questionnaire-Short Form (CTQ-SF), we determined its dimensional structure, measurement invariance across presence of emotional disorders, the association of the CTQ-SF with an analogous interview-based measure (CTI) across presence of

Topologically massive gauge theories and their dual factorized gauge-invariant formulation

International Nuclear Information System (INIS)

Bertrand, Bruno; Govaerts, Jan

2007-01-01

There exists a well-known duality between the Maxwell-Chern-Simons theory and the 'self-dual' massive model in (2 + 1) dimensions. This dual description may be extended to topologically massive gauge theories (TMGT) for forms of arbitrary rank and in any dimension. This communication introduces the construction of this type of duality through a reparametrization of the 'master' theory action. The dual action thereby obtained preserves the full gauge symmetry structure of the original theory. Furthermore, the dual action is factorized into a propagating sector of massive gauge-invariant variables and a decoupled sector of gauge-variant variables defining a pure topological field theory. Combining the results obtained within the Lagrangian and Hamiltonian formulations, a completed structure for a gauge-invariant dual factorization of TMGT is thus achieved. (fast track communication)

Measurement invariance of the strength of motivation for medical school: a multi-group confirmatory factor analysis.

Science.gov (United States)

An, M; Kusurkar, R A; Li, L; Xiao, Y; Zheng, C; Hu, J; Chen, M

2017-07-11

The Strength of Motivation for Medical School-Revised (SMMS-R) questionnaire measures students' motivation for studying medicine. It includes three subscales: 'willingness to sacrifice', 'readiness to start', and 'persistence'. Measurement invariance is a prerequisite for group comparisons. The objectives of this study were to verify the factorial structure of the SMMS-R questionnaire and to investigate it's measurement invariance. A total of 989 medical students were approached, 930 cases were kept for data analysis. Factorial structure of and measurement invariance of the SMMS-R were tested using single and multiple group confirmatory factor analyses with Mplus. Trational Cronbach's α along with McDonald's ω and glb were used to measure internal consistency for each subscale. Internal consistency for subscales and the full instrument were within the acceptable range. A 3-factor structure of the Chinese version of the SMMS-R was supported. Full configural, metric and partial scalar invariance were obtained. The SMMS-R showed measurement invariance across gender and two independent samples. So it can be used for group and cross-cultural comparisons.

Testing strong factorial invariance using three-level structural equation modeling

NARCIS (Netherlands)

Jak, Suzanne

Within structural equation modeling, the most prevalent model to investigate measurement bias is the multigroup model. Equal factor loadings and intercepts across groups in a multigroup model represent strong factorial invariance (absence of measurement bias) across groups. Although this approach is

Cross-National Invariance of Attention-Deficit/Hyperactivity Disorder Factors in Japanese and U.S. University Students

Science.gov (United States)

Davis, J. Mark; Cheung, Shu Fai; Takahashi, Tomone; Shinoda, Haruo; Lindstrom, William A.

2011-01-01

Prior research with children generally supports the two-dimensional structure of Attention-Deficit/Hyperactivity Disorder (ADHD; inattentive and hyperactive/impulsive factors) of the DSM-IV-TR as well as invariance of the two-factor structure across nations and cultures. Research with adults supports either a two-factor or three-factor structure…

Hidden scale invariance of metals

DEFF Research Database (Denmark)

Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.

2015-01-01

Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were...... available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant...

Multigroup confirmatory factor analysis and structural invariance with age of the Behavior Rating Inventory of Executive Function (BRIEF)--French version.

Science.gov (United States)

Fournet, Nathalie; Roulin, Jean-Luc; Monnier, Catherine; Atzeni, Thierry; Cosnefroy, Olivier; Le Gall, Didier; Roy, Arnaud

2015-01-01

The parent and teacher forms of the French version of the Behavioral Rating Inventory of Executive Function (BRIEF) were used to evaluate executive function in everyday life in a large sample of healthy children (N = 951) aged between 5 and 18. Several psychometric methods were applied, with a view to providing clinicians with tools for score interpretation. The parent and teacher forms of the BRIEF were acceptably reliable. Demographic variables (such as age and gender) were found to influence the BRIEF scores. Confirmatory factor analysis was then used to test five competing models of the BRIEF's latent structure. Two of these models (a three-factor model and a two-factor model, both based on a nine-scale structure) had a good fit. However, structural invariance with age was only obtained with the two-factor model. The French version of the BRIEF provides a useful measure of everyday executive function and can be recommended for use in clinical research and practice.

The conformally invariant Laplace-Beltrami operator and factor ordering

International Nuclear Information System (INIS)

Ryan, Michael P.; Turbiner, Alexander V.

2004-01-01

In quantum mechanics the kinetic energy term for a single particle is usually written in the form of the Laplace-Beltrami operator. This operator is a factor ordering of the classical kinetic energy. We investigate other relatively simple factor orderings and show that the only other solution for a conformally flat metric is the conformally invariant Laplace-Beltrami operator. For non-conformally-flat metrics this type of factor ordering fails, by just one term, to give the conformally invariant Laplace-Beltrami operator

Relating measurement invariance, cross-level invariance, and multilevel reliability

OpenAIRE

Jak, S.; Jorgensen, T.D.

2017-01-01

Data often have a nested, multilevel structure, for example when data are collected from children in classrooms. This kind of data complicate the evaluation of reliability and measurement invariance, because several properties can be evaluated at both the individual level and the cluster level, as well as across levels. For example, cross-level invariance implies equal factor loadings across levels, which is needed to give latent variables at the two levels a similar interpretation. Reliabili...

Invariant structures in gauge theories and confinement

International Nuclear Information System (INIS)

Prokhorov, L.V.; Shabanov, S.V.

1991-01-01

The problem of finding all gauge invariants is considered in connection with the problem of confinement. Polylocal gauge tensors are introduced and studied. It is shown (both in physical and pure geometrical approaches) that the path-ordered exponent is the only fundamental bilocal gauge tensor, which means that any irreducible polylocal gauge tensor is built of P-exponents and local tensors (matter fields). The simplest invariant structures in electrodynamics, chromodynamics and a theory with the gauge group SU(2) are considered separately. 23 refs.; 2 figs

Testing the Structural Invariance of the Africultural Coping Systems Inventory Across Three Samples of African Descent Populations

Science.gov (United States)

Utsey, Shawn O.; Brown, Christa; Bolden, Mark A.

2004-01-01

Confirmatory factor analysis was used to test the factorial invariance of the Africultural Coping Systems Inventory's (ACSI) measurement model and underlying factor structure across three independent and ethnically distinct samples of African descent populations. Results indicated that factor pattern coefficients of the ACSI's underlying…

Dimensionality and measurement invariance in the Satisfaction with Life Scale in Norway.

Science.gov (United States)

Clench-Aas, Jocelyne; Nes, Ragnhild Bang; Dalgard, Odd Steffen; Aarø, Leif Edvard

2011-10-01

Results from previous studies examining the dimensionality and factorial invariance of the Satisfaction with Life Scale (SWLS) are inconsistent and often based on small samples. This study examines the factorial structure and factorial invariance of the SWLS in a Norwegian sample. Confirmatory factor analysis (AMOS) was conducted to explore dimensionality and test for measurement invariance in factor structure, factor loadings, intercepts, and residual variance across gender and four age groups in a large (N = 4,984), nationally representative sample of Norwegian men and women (15-79 years). The data supported a modified unidimensional structure. Factor loadings could be constrained to equality between the sexes, indicating metric invariance between genders. Further testing indicated invariance also at the strong and strict levels, thus allowing analyses involving group means. The SWLS was shown to be sensitive to age, however, at the strong and strict levels of invariance testing. In conclusion, the results in this Norwegian study seem to confirm that a unidimensional structure is acceptable, but that a modified single-factor model with correlations between error terms of items 4 and 5 is preferred. Additionally, comparisons may be made between the genders. Caution must be exerted when comparing age groups.

Form factors in quantum integrable models with GL(3)-invariant R-matrix

Energy Technology Data Exchange (ETDEWEB)

Pakuliak, S., E-mail: pakuliak@theor.jinr.ru [Laboratory of Theoretical Physics, JINR, 141980 Dubna, Moscow Reg. (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Reg. (Russian Federation); Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Ragoucy, E., E-mail: eric.ragoucy@lapth.cnrs.fr [Laboratoire de Physique Théorique LAPTH, CNRS and Université de Savoie, BP 110, 74941 Annecy-le-Vieux Cedex (France); Slavnov, N.A., E-mail: nslavnov@mi.ras.ru [Steklov Mathematical Institute, Moscow (Russian Federation)

2014-04-15

We study integrable models solvable by the nested algebraic Bethe ansatz and possessing GL(3)-invariant R-matrix. We obtain determinant representations for form factors of off-diagonal entries of the monodromy matrix. These representations can be used for the calculation of form factors and correlation functions of the XXX SU(3)-invariant Heisenberg chain.

Cosmological disformal invariance

Energy Technology Data Exchange (ETDEWEB)

Domènech, Guillem; Sasaki, Misao [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Naruko, Atsushi, E-mail: guillem.domenech@yukawa.kyoto-u.ac.jp, E-mail: naruko@th.phys.titech.ac.jp, E-mail: misao@yukawa.kyoto-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

2015-10-01

The invariance of physical observables under disformal transformations is considered. It is known that conformal transformations leave physical observables invariant. However, whether it is true for disformal transformations is still an open question. In this paper, it is shown that a pure disformal transformation without any conformal factor is equivalent to rescaling the time coordinate. Since this rescaling applies equally to all the physical quantities, physics must be invariant under a disformal transformation, that is, neither causal structure, propagation speed nor any other property of the fields are affected by a disformal transformation itself. This fact is presented at the action level for gravitational and matter fields and it is illustrated with some examples of observable quantities. We also find the physical invariance for cosmological perturbations at linear and high orders in perturbation, extending previous studies. Finally, a comparison with Horndeski and beyond Horndeski theories under a disformal transformation is made.

Measurement Invariance of Second-Order Factor Model of the Multifactor Leadership Questionnaire (MLQ) across K-12 Principal Gender

Science.gov (United States)

Xu, Lihua; Wubbena, Zane; Stewart, Trae

2016-01-01

Purpose: The purpose of this paper is to investigate the factor structure and the measurement invariance of the Multifactor Leadership Questionnaire (MLQ) across gender of K-12 school principals (n=6,317) in the USA. Design/methodology/approach: Nine first-order factor models and four second-order factor models were tested using confirmatory…

Measurement invariance of Rosenberg Self-Esteem Scale between British and Chinese college students

OpenAIRE

Luo, Chengwen

2010-01-01

The present study examined the factor structure and measurement invariance of the Rosenberg Self-Esteem Scale in college students from Britain (N=150) and China (N=205). Confirmatory factor analyses suggested that the two-factor model, which consisted of a positive self-image factor and a negative self-image factor, could fit the data better than single factor structure especially after deleting the eighth item. Furthermore, factorial structure was invariant across groups in configural level ...

Measurement and Structural Invariance of Parent Ratings of ADHD and ODD Symptoms across Gender for American and Malaysian Children

Science.gov (United States)

Burns, G. Leonard; Walsh, James A.; Gomez, Rapson; Hafetz, Nina

2006-01-01

The purpose of this study was to examine the measurement (configural, metric, scalar, and residual) and structural (factor variance, factor covariance, and factor means) invariance of parent ratings of the attention-deficit/hyperactivity disorder-inattention (ADHD-IN), ADHD-hyperactivity/impulsivity (ADHD-HI), and oppositional defiant disorder…

cDNA cloning and primary structure analysis of invariant chain in ...

African Journals Online (AJOL)

cDNA cloning and primary structure analysis of invariant chain in Chinese Pengze crucian carp. X Liu, W Yu, J Li, F Chen, S Liu, C Wu, J Xu. Abstract. Invariant chain (Ii) plays an important role in MHC class II molecules assembly and exogenous peptide presentation in vertebrates. Although mammalian Ii has been ...

Passion: Does one scale fit all? Construct validity of two-factor passion scale and psychometric invariance over different activities and languages.

Science.gov (United States)

Marsh, Herbert W; Vallerand, Robert J; Lafrenière, Marc-André K; Parker, Philip; Morin, Alexandre J S; Carbonneau, Noémie; Jowett, Sophia; Bureau, Julien S; Fernet, Claude; Guay, Frédéric; Salah Abduljabbar, Adel; Paquet, Yvan

2013-09-01

The passion scale, based on the dualistic model of passion, measures 2 distinct types of passion: Harmonious and obsessive passions are predictive of adaptive and less adaptive outcomes, respectively. In a substantive-methodological synergy, we evaluate the construct validity (factor structure, reliability, convergent and discriminant validity) of Passion Scale responses (N = 3,571). The exploratory structural equation model fit to the data was substantially better than the confirmatory factor analysis solution, and resulted in better differentiated (less correlated) factors. Results from a 13-model taxonomy of measurement invariance supported complete invariance (factor loadings, factor correlations, item uniquenesses, item intercepts, and latent means) over language (French vs. English; the instrument was originally devised in French, then translated into English) and gender. Strong measurement partial invariance over 5 passion activity groups (leisure, sport, social, work, education) indicates that the same set of items is appropriate for assessing passion across a wide variety of activities--a previously untested, implicit assumption that greatly enhances practical utility. Support was found for the convergent and discriminant validity of the harmonious and obsessive passion scales, based on a set of validity correlates: life satisfaction, rumination, conflict, time investment, activity liking and valuation, and perceiving the activity as a passion.

Structural invariance of the Schroedinger equation and chronoprojective geometry

International Nuclear Information System (INIS)

Burdet, G.; Perrin, M.

1983-07-01

We describe an extension of the chronoprojective geometry and show how its automorphisms are related to the invariance properties of the Schroedinger equation describing a quantum test particle in any Newton-Cartan structure

Analyzing vortex breakdown flow structures by assignment of colors to tensor invariants.

Science.gov (United States)

Rütten, Markus; Chong, Min S

2006-01-01

Topological methods are often used to describe flow structures in fluid dynamics and topological flow field analysis usually relies on the invariants of the associated tensor fields. A visual impression of the local properties of tensor fields is often complex and the search of a suitable technique for achieving this is an ongoing topic in visualization. This paper introduces and assesses a method of representing the topological properties of tensor fields and their respective flow patterns with the use of colors. First, a tensor norm is introduced, which preserves the properties of the tensor and assigns the tensor invariants to values of the RGB color space. Secondly, the RGB colors of the tensor invariants are transferred to corresponding hue values as an alternative color representation. The vectorial tensor invariants field is reduced to a scalar hue field and visualization of iso-surfaces of this hue value field allows us to identify locations with equivalent flow topology. Additionally highlighting by the maximum of the eigenvalue difference field reflects the magnitude of the structural change of the flow. The method is applied on a vortex breakdown flow structure inside a cylinder with a rotating lid.

Confirmatory factor analysis and invariance testing between Blacks and Whites of the Multidimensional Health Locus of Control scale.

Science.gov (United States)

LaNoue, Marianna; Harvey, Abby; Mautner, Dawn; Ku, Bon; Scott, Kevin

2015-07-01

The factor structure of the Multidimensional Health Locus of Control scale remains in question. Additionally, research on health belief differences between Black and White respondents suggests that the Multidimensional Health Locus of Control scale may not be invariant. We reviewed the literature regarding the latent variable structure of the Multidimensional Health Locus of Control scale, used confirmatory factor analysis to confirm the three-factor structure of the Multidimensional Health Locus of Control, and analyzed between-group differences in the Multidimensional Health Locus of Control structure and means across Black and White respondents. Our results indicate differences in means and structure, indicating more research is needed to inform decisions regarding whether and how to deploy the Multidimensional Health Locus of Control appropriately.

Gauge-invariant cosmic structures---A dynamic systems approach

International Nuclear Information System (INIS)

Woszczyna, A.

1992-01-01

Gravitational instability is expressed in terms of the dynamic systems theory. The gauge-invariant Ellis-Bruni equation and Bardeen's equation are discussed in detail. It is shown that in an open universe filled with matter of constant sound velocity the Jeans criterion does not adequately define the length scale of the gravitational structure

Structure of BRS-invariant local functionals

International Nuclear Information System (INIS)

Brandt, F.

1993-01-01

For a large class of gauge theories a nilpotent BRS-operator s is constructed and its cohomology in the space of local functionals of the off-shell fields is shown to be isomorphic to the cohomology of s=s+d on functions f(C,T) of tensor fields T and of variables C which are constructed of the ghosts and the connection forms. The result allows general statements about the structure of invariant classical actions and anomaly cadidates whose BRS-variation vanishes off-shell. The assumptions under which the result holds are thoroughly discussed. (orig.)

Measurement Invariance Testing of a Three-Factor Model of Parental Warmth, Psychological Control, and Knowledge across European and Asian/Pacific Islander American Youth.

Science.gov (United States)

Luk, Jeremy W; King, Kevin M; McCarty, Carolyn A; Stoep, Ann Vander; McCauley, Elizabeth

2016-06-01

While the interpretation and effects of parenting on developmental outcomes may be different across European and Asian/Pacific Islander (API) American youth, measurement invariance of parenting constructs has rarely been examined. Utilizing multiple-group confirmatory factor analysis, we examined whether the latent structure of parenting measures are equivalent or different across European and API American youth. Perceived parental warmth, psychological control, and knowledge were reported by a community sample of 325 adolescents (242 Europeans and 83 APIs). Results indicated that one item did not load on mother psychological control for API American youth. After removing this item, we found metric invariance for all parenting dimensions, providing support for cross-cultural consistency in the interpretation of parenting items. Scalar invariance was found for father parenting, whereas three mother parenting items were non-invariant across groups at the scalar level. After taking into account several minor forms of measurement non-invariance, non-invariant factor means suggested that API Americans perceived lower parental warmth and knowledge but higher parental psychological control than European Americans. Overall, the degree of measurement non-invariance was not extensive and was primarily driven by a few parenting items. All but one parenting item included in this study may be used for future studies across European and API American youth.

Confirmatory factor analysis and sample invariance of the Chinese version of Somatosensory Amplification Scale (ChSAS) among Chinese adolescents

OpenAIRE

Tam, B. K.; Wong, W. S.

2011-01-01

Objective: This paper aimed to evaluate the factor structure of the Chinese version of Somatosensory Amplification Scale (ChSAS) in a sample of Chinese adolescents across different grade levels using confirmatory factor analysis (CFA). Methods: A total of 1991 Chinese adolescents completed the ChSAS. CFA assessed the fit of the one-factor model to the entire sample. Factorial invariance of the ChSAS was also examined across grade levels using multigroup CFA. Results: Results of CFA confirmed ...

Invariant molecular-dynamics approach to structural phase transitions

International Nuclear Information System (INIS)

Wentzcovitch, R.M.

1991-01-01

Two fictitious Lagrangians to be used in molecular-dynamics simulations with variable cell shape and suitable to study problems like structural phase transitions are introduced. Because they are invariant with respect to the choice of the simulation cell edges and eliminate symmetry breaking associated with the fictitious part of the dynamics, they improve the physical content of numerical simulations that up to now have been done by using Parrinello-Rahman dynamics

Isomorph invariance of the structure and dynamics of classical crystals

DEFF Research Database (Denmark)

Albrechtsen, Dan; Olsen, Andreas Elmerdahl; Pedersen, Ulf Rørbæk

2014-01-01

This paper shows by computer simulations that some crystalline systems have curves in their thermodynamic phase diagrams, so-called isomorphs, along which structure and dynamics in reduced units are invariant to a good approximation. The crystals are studied in a classical-mechanical framework...

The Shame and Guilt Scales of the Test of Self-Conscious Affect-Adolescent (TOSCA-A): Factor Structure, Concurrent and Discriminant Validity, and Measurement and Structural Invariance Across Ratings of Males and Females.

Science.gov (United States)

Watson, Shaun; Gomez, Rapson; Gullone, Eleonora

2017-06-01

This study examined various psychometric properties of the items comprising the shame and guilt scales of the Test of Self-Conscious Affect-Adolescent. A total of 563 adolescents (321 females and 242 males) completed these scales, and also measures of depression and empathy. Confirmatory factor analysis provided support for an oblique two-factor model, with the originally proposed shame and guilt items comprising shame and guilt factors, respectively. Also, shame correlated with depression positively and had no relation with empathy. Guilt correlated with depression negatively and with empathy positively. Thus, there was support for the convergent and discriminant validity of the shame and guilt factors. Multiple-group confirmatory factor analysis comparing females and males, based on the chi-square difference test, supported full metric invariance, the intercept invariance of 26 of the 30 shame and guilt items, and higher latent mean scores among females for both shame and guilt. Comparisons based on the difference in root mean squared error of approximation values supported full measurement invariance and no gender difference for latent mean scores. The psychometric and practical implications of the findings are discussed.

A cross-national analysis of measurement invariance of the Satisfaction With Life Scale.

Science.gov (United States)

Whisman, Mark A; Judd, Charles M

2016-02-01

Measurement invariance of the Satisfaction With Life Scale (SWLS) was examined in probability samples of adults 50-79 years of age living in the United States, England, and Japan. Confirmatory factor analysis modeling was used to test for multigroup measurement invariance of a single-factor structure of the SWLS. Results support a single-factor structure of the SWLS across the 3 countries, with tests of measurement invariance of the SWLS supporting its configural invariance and metric invariance. These results suggest that the SWLS may be used as a single-factor measure of life satisfaction in the United States, England, and Japan, and that it is appropriate to compare correlates of the SWLS in middle-aged and older adults across these 3 countries. However, results provided evidence for only partial scalar invariance, with the intercept for SWLS Item 4 varying across countries. Cross-national comparisons of means revealed a lower mean at the latent variable level for the Japanese sample than for the other 2 samples. In addition, over and above the latent mean difference, the Japanese sample also manifested a significantly lower intercept on Item 4. Implications of the findings for research on cross-national comparisons of life satisfaction in European American and East Asian countries are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Memory assessment and depression: testing for factor structure and measurement invariance of the Wechsler Memory Scale-Fourth Edition across a clinical and matched control sample.

Science.gov (United States)

Pauls, Franz; Petermann, Franz; Lepach, Anja Christina

2013-01-01

Between-group comparisons are permissible and meaningfully interpretable only if diagnostic instruments are proved to measure the same latent dimensions across different groups. Addressing this issue, the present study was carried out to provide a rigorous test of measurement invariance. Confirmatory factor analyses were used to determine which model solution could best explain memory performance as measured by the Wechsler Memory Scale-Fourth Edition (WMS-IV) in a clinical depression sample and in healthy controls. Multigroup confirmatory factor analysis was conducted to evaluate the evidence for measurement invariance. A three-factor model solution including the dimensions of auditory memory, visual memory, and visual working memory was identified to best fit the data in both samples, and measurement invariance was partially satisfied. The results supported clinical utility of the WMS-IV--that is, auditory and visual memory performances of patients with depressive disorders are interpretable on the basis of the WMS-IV standardization data. However, possible differences in visual working memory functions between healthy and depressed individuals could restrict comparisons of the WMS-IV working memory index.

Gauge invariance and quantization applied to atom and nucleon internal structure

International Nuclear Information System (INIS)

Wang Fan; Sun Weimin; Chen Xiangsong; LU Xiaofu; Goldman, T.

2010-01-01

The prevailing theoretical quark and gluon momentum,orbital angular momentum and spin operators, satisfy either gauge invariance or the corresponding canonical commutation relation, but one never has these operators which satisfy both except the quark spin. The conflicts between gauge invariance and the canonical quantization requirement of these operators are discussed. A new set of quark and gluon momentum, orbital angular momentum and spin operators, which satisfy both gauge invariance and canonical momentum and angular momentum commutation relation, are proposed.To achieve such a proper decomposition the key point is to separate the gauge field into the pure gauge and the gauge covariant parts. The same conflicts also exist in QED and quantum mechanics, and have been solved in the same manner. The impacts of this new decomposition to the nucleon internal structure are discussed. (authors)

Validation of the Dyadic Coping Inventory with Chinese couples: Factorial structure, measurement invariance, and construct validity.

Science.gov (United States)

Xu, Feng; Hilpert, Peter; Randall, Ashley K; Li, Qiuping; Bodenmann, Guy

2016-08-01

The Dyadic Coping Inventory (DCI, Bodenmann, 2008) assesses how couples support each other when facing individual (e.g., workload) and common (e.g., parenting) stressors. Specifically, the DCI measures partners' perceptions of their own (Self) and their partners' behaviors (Partner) when facing individual stressors, and partners' common coping behaviors when facing common stressors (Common). To date, the DCI has been validated in 6 different languages from individualistic Western cultures; however, because culture can affect interpersonal interactions, it is unknown whether the DCI is a reliable measure of coping behaviors for couples living in collectivistic Eastern cultures. Based on data from 474 Chinese couples (N = 948 individuals), the current study examined the Chinese version of the DCI's factorial structure, measurement invariance (MI), and construct validity of test scores. Using 3 cultural groups (China, Switzerland, and the United States [U.S.]), confirmatory factor analysis revealed a 5-factor structure regarding Self and Partner and a 2-factor structure regarding Common dyadic coping (DC). Results from analyses of MI indicated that the DCI subscales met the criteria for configural, metric, and full/partial scalar invariance across cultures (Chinese-Swiss and Chinese-U.S.) and genders (Chinese men and women). Results further revealed good construct validity of the DCI test scores. In all, the Chinese version of the DCI can be used for measuring Chinese couples' coping behaviors, and is available for cross-cultural studies examining DC behaviors between Western and Eastern cultures. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Parents' and Adolescents' Perspectives on Parenting: Evaluating Conceptual Structure, Measurement Invariance, and Criterion Validity.

Science.gov (United States)

Janssens, Annelies; Goossens, Luc; Van Den Noortgate, Wim; Colpin, Hilde; Verschueren, Karine; Van Leeuwen, Karla

2015-08-01

Uncertainty persists regarding adequate measurement of parenting behavior during early adolescence. The present study aimed to clarify the conceptual structure of parenting by evaluating three different models that include support, psychological control, and various types of behavioral control (i.e., proactive, punitive, and harsh punitive control). Furthermore, we examined measurement invariance of parenting ratings by 1,111 Flemish adolescents from Grade 7 till 9, their mother, and father. Finally, criterion validity of parenting ratings was estimated in relation to adolescent problem behavior. Results supported a five-factor parenting model indicating multiple aspects of behavioral control, with punitive and harsh punitive control as more intrusive forms and proactive control as a more supportive form. Similar constructs were measured for adolescents, mothers, and fathers (i.e., configural and metric invariance), however on a different scale (i.e., scalar noninvariance). Future research and clinical practices should acknowledge these findings in order to fully grasp the parenting process. © The Author(s) 2014.

Dimensional Structure and Measurement Invariance of the Schizotypal Personality Questionnaire - Brief Revised (SPQ-BR) Scores Across American and Spanish Samples.

Science.gov (United States)

Fonseca-Pedrero, Eduardo; Cohen, Alex; Ortuño-Sierra, Javier; de Álbeniz, Alicia Pérez; Muñiz, José

2017-08-01

The main goal of the present study was to test the measurement equivalence of the Schizotypal Personality Questionnaire - Brief Revised (SPQ-BR) scores in a large sample of Spanish and American non-clinical young adults. The sample was made up of 5,625 young adults (M = 19.65 years; SD = 2.53; 38.5% males). Study of the internal structure, using confirmatory factor analysis (CFA), revealed that SPQ-BR items were grouped in a theoretical internal structure of nine first-order factors. Moreover, three or four second-order factor and bifactor models showed adequate goodness-of-fit indices. Multigroup CFA showed that the nine lower-order factor models of the SPQ-BR had configural and weak measurement invariance and partial strong measurement invariance across country. The reliability of the SPQ-BR scores, estimated with omega, ranged from 0.67 to 0.91. Using the item response theory framework, the SPQ-BR provides more accurate information at the medium and high end of the latent trait. Statistically significant differences were found in the raw scores of the SPQ-BR subscales and dimensions across samples. The American group scored higher than the Spanish group in all SPQ-BR domains except Ideas of Reference and Suspiciousness. The finding of comparable factor structure in cross-cultural samples would lend further support to the continuum model of psychosis spectrum disorders. In addition, these results provide new information about the factor structure of schizotypal traits and support the validity and utility of this measure in cross-cultural research.

ATS drugs molecular structure representation using refined 3D geometric moment invariants

Czech Academy of Sciences Publication Activity Database

Pratama, S. F.; Muda, A. K.; Choo, J. H.; Flusser, Jan; Abraham, A.

2017-01-01

Roč. 55, č. 10 (2017), s. 1951-1963 ISSN 0259-9791 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : 3D moment invariants * Geometric moment invariants * ATS drugs * Molecular similarity * Molecular descriptors Subject RIV: JD - Computer Applications, Robotics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 1.308, year: 2016 http://library.utia.cas.cz/separaty/2017/ZOI/flusser-0479217.pdf

Unexplained structure in (μ,π) invariant mass distribution

International Nuclear Information System (INIS)

Ramm, C.A.

2000-01-01

Structures in invariant mass distributions from (μ,π) combinations in the range 0.380 μ -π 0.470 GeV from neutrino and kaon experiments are presented in comparable formats. No artifacts have been found to account for any part of the structure. Hypotheses that the similarities are due to recurrent statistical fluctuations are beyond credibility. My conclusion is that the similarities are overwhelming evidence that the structure is of an unexplained physical origin. It includes an enhancement which would accord with the decay of a narrow (μ,π) state of mass 0.429 GeV. The purpose of this report is to request and enable every experimenter with precise M μ , π distributions to investigate their degree of correspondence with these analyses (author)

Computational invariant theory

CERN Document Server

Derksen, Harm

2015-01-01

This book is about the computational aspects of invariant theory. Of central interest is the question how the invariant ring of a given group action can be calculated. Algorithms for this purpose form the main pillars around which the book is built. There are two introductory chapters, one on Gröbner basis methods and one on the basic concepts of invariant theory, which prepare the ground for the algorithms. Then algorithms for computing invariants of finite and reductive groups are discussed. Particular emphasis lies on interrelations between structural properties of invariant rings and computational methods. Finally, the book contains a chapter on applications of invariant theory, covering fields as disparate as graph theory, coding theory, dynamical systems, and computer vision. The book is intended for postgraduate students as well as researchers in geometry, computer algebra, and, of course, invariant theory. The text is enriched with numerous explicit examples which illustrate the theory and should be ...

The CES-D as a Measure of Psychological Distress Among International Students: Measurement and Structural Invariance Across Gender.

Science.gov (United States)

Suh, Hanna; van Nuenen, Marieke; Rice, Kenneth G

2017-10-01

Detecting psychological distress among international students can be challenging given diverse languages, cultural backgrounds, and lack of refined measurement properties of measures tailored to international students. Despite the challenges, ensuring that a psychological distress measure works effectively has considerable potential value for assessment purposes. The current study evaluates the measurement properties of a short 10-item version of Radloff's Center for Epidemiologic Studies Depression Scale (CES-D). Grounded in long-standing evidence on gender differences in depressive symptoms, specific attention was given to examining measurement invariance of the CES-D Short-form across women and men. Based on a large, two-cohort sample of international students ( N = 468), and through multiple analyses evaluating factor structure and measurement invariance, we derived an even briefer, seven-item single-factor form of the CES-D (CES-D Short-form International) that can be used with international students.

Assessing infertility-related stress: the factor structure of the Fertility Problem Inventory in Italian couples undergoing infertility treatment.

Science.gov (United States)

Donarelli, Zaira; Gullo, Salvatore; Lo Coco, Gianluca; Marino, Angelo; Scaglione, Piero; Volpes, Aldo; Allegra, Adolfo

2015-01-01

The factor structure of the Fertility Problem Inventory (FPI) and its invariance across gender were examined in Italian couples undergoing infertility treatment. About 1000 subjects (both partners of 500 couples) completed two questionnaires prior to commencing infertility treatment at a private Clinic in Palermo, Italy. Confirmatory Factor Analysis demonstrated that the original factor structure of the FPI was partially confirmed. Two correlated factors (Infertility Life Domains and Importance of Parenthood) were obtained via a post hoc Exploratory Factor Analysis. Finally, the invariance of this factor structure across gender was confirmed. The study supported the relevance of two interrelated factors specific to infertility stress which could help clinicians to focus on the core infertility-related stress domains of infertile couples.

Examining the Impact of Gender on the Factor Structure of the Psychopathic Personality Inventory--Revised

Science.gov (United States)

Anestis, Joye C.; Caron, Kelly M.; Carbonell, Joyce L.

2011-01-01

Research on the factor structure of psychopathy has yielded mixed results, supporting anywhere from one to three factors. Additionally, most of this research has used all-male samples, and the possibility of structural invariance across gender has not been examined. Using a mixed-gender sample of 360 undergraduates, the factor structure of the…

The Strengths and Difficulties Questionnaire (SDQ): Factor Structure and Gender Equivalence in Norwegian Adolescents.

Science.gov (United States)

Bøe, Tormod; Hysing, Mari; Skogen, Jens Christoffer; Breivik, Kyrre

2016-01-01

Although frequently used with older adolescents, few studies of the factor structure, internal consistency and gender equivalence of the SDQ exists for this age group, with inconsistent findings. In the present study, confirmatory factor analysis (CFA) was used to evaluate the five-factor structure of the SDQ in a population sample of 10,254 16-18 year-olds from the youth@hordaland study. Measurement invariance across gender was assessed using multigroup CFA. A modestly modified five-factor solution fitted the data acceptably, accounting for one cross loading and some local dependencies. Importantly, partial measurement non-invariance was identified, with differential item functioning in eight items, and higher correlations between emotional and conduct problems for boys compared to girls. Implications for use clinically and in research are discussed.

Link invariants from finite Coxeter racks

OpenAIRE

Nelson, Sam; Wieghard, Ryan

2008-01-01

We study Coxeter racks over $\\mathbb{Z}_n$ and the knot and link invariants they define. We exploit the module structure of these racks to enhance the rack counting invariants and give examples showing that these enhanced invariants are stronger than the unenhanced rack counting invariants.

A scale invariance criterion for LES parametrizations

Directory of Open Access Journals (Sweden)

Urs Schaefer-Rolffs

2015-01-01

Full Text Available Turbulent kinetic energy cascades in fluid dynamical systems are usually characterized by scale invariance. However, representations of subgrid scales in large eddy simulations do not necessarily fulfill this constraint. So far, scale invariance has been considered in the context of isotropic, incompressible, and three-dimensional turbulence. In the present paper, the theory is extended to compressible flows that obey the hydrostatic approximation, as well as to corresponding subgrid-scale parametrizations. A criterion is presented to check if the symmetries of the governing equations are correctly translated into the equations used in numerical models. By applying scaling transformations to the model equations, relations between the scaling factors are obtained by demanding that the mathematical structure of the equations does not change.The criterion is validated by recovering the breakdown of scale invariance in the classical Smagorinsky model and confirming scale invariance for the Dynamic Smagorinsky Model. The criterion also shows that the compressible continuity equation is intrinsically scale-invariant. The criterion also proves that a scale-invariant turbulent kinetic energy equation or a scale-invariant equation of motion for a passive tracer is obtained only with a dynamic mixing length. For large-scale atmospheric flows governed by the hydrostatic balance the energy cascade is due to horizontal advection and the vertical length scale exhibits a scaling behaviour that is different from that derived for horizontal length scales.

The Strengths and Difficulties Questionnaire (SDQ: Factor Structure and Gender Equivalence in Norwegian Adolescents.

Directory of Open Access Journals (Sweden)

Tormod Bøe

Full Text Available Although frequently used with older adolescents, few studies of the factor structure, internal consistency and gender equivalence of the SDQ exists for this age group, with inconsistent findings. In the present study, confirmatory factor analysis (CFA was used to evaluate the five-factor structure of the SDQ in a population sample of 10,254 16-18 year-olds from the youth@hordaland study. Measurement invariance across gender was assessed using multigroup CFA. A modestly modified five-factor solution fitted the data acceptably, accounting for one cross loading and some local dependencies. Importantly, partial measurement non-invariance was identified, with differential item functioning in eight items, and higher correlations between emotional and conduct problems for boys compared to girls. Implications for use clinically and in research are discussed.

Invariants of generalized Lie algebras

International Nuclear Information System (INIS)

Agrawala, V.K.

1981-01-01

Invariants and invariant multilinear forms are defined for generalized Lie algebras with arbitrary grading and commutation factor. Explicit constructions of invariants and vector operators are given by contracting invariant forms with basic elements of the generalized Lie algebra. The use of the matrix of a linear map between graded vector spaces is emphasized. With the help of this matrix, the concept of graded trace of a linear operator is introduced, which is a rich source of multilinear forms of degree zero. To illustrate the use of invariants, a characteristic identity similar to that of Green is derived and a few Racah coefficients are evaluated in terms of invariants

Liquid structure and temperature invariance of sound velocity in supercooled Bi melt

International Nuclear Information System (INIS)

Emuna, M.; Mayo, M.; Makov, G.; Greenberg, Y.; Caspi, E. N.; Yahel, E.; Beuneu, B.

2014-01-01

Structural rearrangement of liquid Bi in the vicinity of the melting point has been proposed due to the unique temperature invariant sound velocity observed above the melting temperature, the low symmetry of Bi in the solid phase and the necessity of overheating to achieve supercooling. The existence of this structural rearrangement is examined by measurements on supercooled Bi. The sound velocity of liquid Bi was measured into the supercooled region to high accuracy and it was found to be invariant over a temperature range of ∼60°, from 35° above the melting point to ∼25° into the supercooled region. The structural origin of this phenomenon was explored by neutron diffraction structural measurements in the supercooled temperature range. These measurements indicate a continuous modification of the short range order in the melt. The structure of the liquid is analyzed within a quasi-crystalline model and is found to evolve continuously, similar to other known liquid pnictide systems. The results are discussed in the context of two competing hypotheses proposed to explain properties of liquid Bi near the melting: (i) liquid bismuth undergoes a structural rearrangement slightly above melting and (ii) liquid Bi exhibits a broad maximum in the sound velocity located incidentally at the melting temperature

Adolescent depressive symptoms in India, Australia and USA: Exploratory Structural Equation Modelling of cross-national invariance and predictions by gender and age.

Science.gov (United States)

Lewis, Andrew J; Rowland, Bosco; Tran, Aiden; Solomon, Renatti F; Patton, George C; Catalano, Richard F; Toumbourou, John W

2017-04-01

The present study compares depressive symptoms in adolescents from three countries: Mumbai, India; Seattle, United States; and Melbourne, Australia measured using the Short Moods and Feelings Questionnaire (SMFQ). The study cross nationally compares SMFQ depressive symptom responses by age and gender. Data from a cross-nationally matched survey were used to compare factorial and measurement characteristics from samples of students from Grade 7 and 9 in Mumbai, India (n=3268) with the equivalent cohorts in the Washington State, USA (n=1907) and Victoria, Australia (n=1900). Exploratory Structural Equation Modelling (ESEM) was used to cross-nationally examine factor structure and measurement invariance. A number of reports suggesting that SMFQ is uni-dimensional were not supported in findings from any country. A model with two factors was a better fit and suggested a first factor clustering symptoms that were affective and physiologically based symptoms and a second factor of self-critical, cognitive symptoms. The two-factor model showed convincing cross national configural invariance and acceptable measurement invariance. The present findings revealed that adolescents in Mumbai, India, reported substantially higher depressive symptoms in both factors, but particularly for the self-critical dimension, as compared to their peers in Australia and the USA and that males in Mumbai report high levels of depressive symptoms than females in Mumbai. the cross sectional study collected data for adolescents in Melbourne and Seattle in 2002 and the data for adolescents in Mumbai was obtained in 2010-2011 CONCLUSIONS: These findings suggest that previous findings in developed nations of higher depressive symptoms amongst females compared to males may have an important cultural component and cannot be generalised as a universal feature of adolescent development. Copyright © 2017 Elsevier B.V. All rights reserved.

Internal Structure and Partial Invariance across Gender in the Spanish Version of the Reasoning Test Battery.

Science.gov (United States)

Elosua, Paula; Mujika, Josu

2015-10-13

The Reasoning Test Battery (BPR) is an instrument built on theories of the hierarchical organization of cognitive abilities and therefore consists of different tasks related with abstract, numerical, verbal, practical, spatial and mechanical reasoning. It was originally created in Belgium and later adapted to Portuguese. There are three forms of the battery consisting of different items and scales which cover an age range from 9 to 22. This paper focuses on the adaptation of the BPR to Spanish, and analyzes different aspects of its internal structure: (a) exploratory item factor analysis was applied to assess the presence of a dominant factor for each partial scale; (b) the general underlined model was evaluated through confirmatory factor analysis, and (c) factorial invariance across gender was studied. The sample consisted of 2624 Spanish students. The results concluded the presence of a general factor beyond the scales, with equivalent values for men and women, and gender differences in the factorial structure which affect the numerical reasoning, abstract reasoning and mechanical reasoning scales.

A conformal gauge invariant functional for Weyl structures and the first variation formula

OpenAIRE

Ichiyama, Toshiyuki; Furuhata, Hitoshi; Urakawa, Hajime

1999-01-01

We consider a new conformal gauge invariant functional which is a natural curvature functional on the space of Weyl structures. We derive the first variation formula of its functional and characterize its critical points.

Factor Structure, Reliability and Measurement Invariance of the Alberta Context Tool and the Conceptual Research Utilization Scale, for German Residential Long Term Care

Science.gov (United States)

Hoben, Matthias; Estabrooks, Carole A.; Squires, Janet E.; Behrens, Johann

2016-01-01

We translated the Canadian residential long term care versions of the Alberta Context Tool (ACT) and the Conceptual Research Utilization (CRU) Scale into German, to study the association between organizational context factors and research utilization in German nursing homes. The rigorous translation process was based on best practice guidelines for tool translation, and we previously published methods and results of this process in two papers. Both instruments are self-report questionnaires used with care providers working in nursing homes. The aim of this study was to assess the factor structure, reliability, and measurement invariance (MI) between care provider groups responding to these instruments. In a stratified random sample of 38 nursing homes in one German region (Metropolregion Rhein-Neckar), we collected questionnaires from 273 care aides, 196 regulated nurses, 152 allied health providers, 6 quality improvement specialists, 129 clinical leaders, and 65 nursing students. The factor structure was assessed using confirmatory factor models. The first model included all 10 ACT concepts. We also decided a priori to run two separate models for the scale-based and the count-based ACT concepts as suggested by the instrument developers. The fourth model included the five CRU Scale items. Reliability scores were calculated based on the parameters of the best-fitting factor models. Multiple-group confirmatory factor models were used to assess MI between provider groups. Rather than the hypothesized ten-factor structure of the ACT, confirmatory factor models suggested 13 factors. The one-factor solution of the CRU Scale was confirmed. The reliability was acceptable (>0.7 in the entire sample and in all provider groups) for 10 of 13 ACT concepts, and high (0.90–0.96) for the CRU Scale. We could demonstrate partial strong MI for both ACT models and partial strict MI for the CRU Scale. Our results suggest that the scores of the German ACT and the CRU Scale for nursing

Confirmatory factor analytic investigation of variance composition, gender invariance, and validity of the Male Role Norms Inventory-Adolescent-revised (MRNI-A-r).

Science.gov (United States)

Levant, Ronald F; McDermott, Ryon C; Hewitt, Amber A; Alto, Kathleen M; Harris, Kyle T

2016-10-01

Confirmatory factor analysis of responses to the Male Role Norms Inventory-Adolescent-revised (MRNI-A-r) from 384 middle school students (163 boys, 221 girls) indicated that the best fit to the data was a bifactor model incorporating the hypothesized 3-factor structure while explicitly modeling an additional, general factor. Specifically, each item-level indicator loaded simultaneously on 2 factors: a general traditional masculinity ideology factor and a specific factor corresponding to 1 of the 3 hypothesized masculine norms for adolescents: Emotionally Detached Dominance, Toughness, and Avoidance of Femininity. Invariance testing across gender supported metric invariance for the general factor only. Although item loadings on the general factor were similar across boys and girls, the specific factor loadings varied substantially, with many becoming nonsignificant in the presence of the general factor for girls. A structural regression analysis predicting latent variables of the Meanings of Adolescent Masculinity Scale (MAMS), the Rosenberg Self-esteem Scale, and the Discipline, School Difficulties, and Positive Behavior Scale (DSDPBS) indicated that the general factor was a strong predictor of MAMS for both genders and DSDPBS for girls. Findings indicate that the MRNI-A-r general factor is a valid and reliable indicator of overall internalization of traditional masculinity ideology in adolescents; however, the specific factors may have different meanings for boys as compared with girls and lack validity in the presence of the general factor. These findings are consistent with a developmental perspective of gender ideology that views adolescence as a time when a differentiated cognitive schema of masculine norms is beginning to develop. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Invariant factors, Julia equivalences and the (abstract) Mandelbrot set

CERN Document Server

Keller, Karsten

2000-01-01

This book is mainly devoted to the combinatorics of quadratic holomorphic dynamics. The conceptual kernel is a self-contained abstract counterpart of connected quadratic Julia sets which is built on Thurston's concept of a quadratic invariant lamination and on symbolic descriptions of the angle-doubling map. The theory obtained is illustrated in the complex plane. It is used to give rigorous proofs of some well-known and some partially new statements on the structure of the Mandelbrot set. The text is intended for graduate students and researchers. Some elementary knowledge in topology and in functions of one complex variable is assumed.

Factor structure of the Body Appreciation Scale among Malaysian women.

Science.gov (United States)

Swami, Viren; Chamorro-Premuzic, Tomas

2008-12-01

The present study examined the factor structure of a Malay version of the Body Appreciation Scale (BAS), a recently developed scale for the assessment of positive body image that has been shown to have a unidimensional structure in Western settings. Results of exploratory and confirmatory factor analyses based on data from community sample of 591 women in Kuala Lumpur, Malaysia, failed to support a unidimensional structure for the Malay BAS. Results of a confirmatory factor analysis suggested two stable factors, which were labelled 'General Body Appreciation' and 'Body Image Investment'. Multi-group analysis showed that the two-factor structure was invariant for both Malaysian Malay and Chinese women, and that there were no significant ethnic differences on either factor. Results also showed that General Body Appreciation was significant negatively correlated with participants' body mass index. These results are discussed in relation to possible cross-cultural differences in positive body image.

Asymptotics of pion electromagnetics form factor in scale invariant quark model

International Nuclear Information System (INIS)

Efremov, A.V.; Radyushkin, A.V.

1976-01-01

A consistent relativistic approach is proposed to the investigation of asymptotic behaviour of form factor of a system, composed of two spinor particles, interacting with the vector of (pseudo) scalar neutral field. It is shown that the assumption of finite and small asymptotical value of quark-gluon interaction invariant charge at small distances (g 9 2 9 2 ln(-Q 2 ) 2 values (Q 2 is squared momentum)

Refined algebraic quantisation in a system with nonconstant gauge invariant structure functions

International Nuclear Information System (INIS)

Martínez-Pascual, Eric

2013-01-01

In a previous work [J. Louko and E. Martínez-Pascual, “Constraint rescaling in refined algebraic quantisation: Momentum constraint,” J. Math. Phys. 52, 123504 (2011)], refined algebraic quantisation (RAQ) within a family of classically equivalent constrained Hamiltonian systems that are related to each other by rescaling one momentum-type constraint was investigated. In the present work, the first steps to generalise this analysis to cases where more constraints occur are developed. The system under consideration contains two momentum-type constraints, originally abelian, where rescalings of these constraints by a non-vanishing function of the coordinates are allowed. These rescalings induce structure functions at the level of the gauge algebra. Providing a specific parametrised family of real-valued scaling functions, the implementation of the corresponding rescaled quantum momentum-type constraints is performed using RAQ when the gauge algebra: (i) remains abelian and (ii) undergoes into an algebra of a nonunimodular group with nonconstant gauge invariant structure functions. Case (ii) becomes the first example known to the author where an open algebra is handled in refined algebraic quantisation. Challenging issues that arise in the presence of non-gauge invariant structure functions are also addressed

Lorentz invariance with an invariant energy scale.

Science.gov (United States)

Magueijo, João; Smolin, Lee

2002-05-13

We propose a modification of special relativity in which a physical energy, which may be the Planck energy, joins the speed of light as an invariant, in spite of a complete relativity of inertial frames and agreement with Einstein's theory at low energies. This is accomplished by a nonlinear modification of the action of the Lorentz group on momentum space, generated by adding a dilatation to each boost in such a way that the Planck energy remains invariant. The associated algebra has unmodified structure constants. We also discuss the resulting modifications of field theory and suggest a modification of the equivalence principle which determines how the new theory is embedded in general relativity.

Foliated vector fields, the Godbillon-Vey invariant and the invariant I(F)

International Nuclear Information System (INIS)

Banyaga, A.; Landa, Alain Musesa

2004-03-01

We prove that if the invariant I(F) constructed in 'An invariant of contact structures and transversally oriented foliations', Ann. Global Analysis and Geom. 14(1996) 427-441 (A. Banyaga), through the Lie algebra of infinitesimal automorphisms of transversally oriented foliations F is trivial, then the Godbillon-Vey invariant GV (F) of F is also trivial, but that the converse is not true. For codimension one foliations, the restrictions I τ , (F) of I(F) to the Lie subalgebra of vector fields tangent to the leaves is the Reeb class R(F) of F. We also prove that if there exists a foliated vector field which is everywhere transverse to a codimension one foliation, then the Reeb class R(F) is trivial, hence so is the GV(F) invariant. (author)

Assessing diabetes support in adolescents: factor structure of the Modified Diabetes Social Support Questionnaire (M-DSSQ-Family)

NARCIS (Netherlands)

Malik, J.A.; Koot, H.M.

2011-01-01

Objectives: To determine the underlying factor structure of diabetes specific support using a modified diabetes family social support questionnaire, the M-DSSQ-Family, in one half of a sample of adolescents with type 1 diabetes, confirm it in the second half, test invariance in factor structure

Invariant sets for Windows

CERN Document Server

Morozov, Albert D; Dragunov, Timothy N; Malysheva, Olga V

1999-01-01

This book deals with the visualization and exploration of invariant sets (fractals, strange attractors, resonance structures, patterns etc.) for various kinds of nonlinear dynamical systems. The authors have created a special Windows 95 application called WInSet, which allows one to visualize the invariant sets. A WInSet installation disk is enclosed with the book.The book consists of two parts. Part I contains a description of WInSet and a list of the built-in invariant sets which can be plotted using the program. This part is intended for a wide audience with interests ranging from dynamical

Gauge invariance and canonical quantization applied in the study of internal structure of gauge field systems

International Nuclear Information System (INIS)

Wang Fan; Chen Xiangsong; Lue Xiaofu; Sun Weiming; Goldman, T.

2010-01-01

It is unavoidable to deal with the quark and gluon momentum and angular momentum contributions to the nucleon momentum and spin in the study of nucleon internal structure. However, we never have the quark and gluon momentum, orbital angular momentum and gluon spin operators which satisfy both the gauge invariance and the canonical momentum and angular momentum commutation relations. The conflicts between the gauge invariance and canonical quantization requirement of these operators are discussed. A new set of quark and gluon momentum, orbital angular momentum and spin operators, which satisfy both the gauge invariance and canonical momentum and angular momentum commutation relations, are proposed. The key point to achieve such a proper decomposition is to separate the gauge field into the pure gauge and the gauge covariant parts. The same conflicts also exist in QED and quantum mechanics and have been solved in the same manner. The impacts of this new decomposition to the nucleon internal structure are discussed.

Gauge-invariant factorization and canonical quantization of topologically massive gauge theories in any dimension

International Nuclear Information System (INIS)

Bertrand, Bruno; Govaerts, Jan

2007-01-01

Abelian topologically massive gauge theories (TMGT) provide a topological mechanism to generate mass for a bosonic p-tensor field in any spacetime dimension. These theories include the (2+1)-dimensional Maxwell-Chern-Simons and (3+1)-dimensional Cremmer-Scherk actions as particular cases. Within the Hamiltonian formulation, the embedded topological field theory (TFT) sector related to the topological mass term is not manifest in the original phase space. However, through an appropriate canonical transformation, a gauge-invariant factorization of phase space into two orthogonal sectors is feasible. The first of these sectors includes canonically conjugate gauge-invariant variables with free massive excitations. The second sector, which decouples from the total Hamiltonian, is equivalent to the phase-space description of the associated non-dynamical pure TFT. Within canonical quantization, a likewise factorization of quantum states thus arises for the full spectrum of TMGT in any dimension. This new factorization scheme also enables a definition of the usual projection from TMGT onto topological quantum field theories in a most natural and transparent way. None of these results rely on any gauge-fixing procedure whatsoever

Measurement invariance within and between individuals: a distinct problem in testing the equivalence of intra- and inter-individual model structures.

Science.gov (United States)

Adolf, Janne; Schuurman, Noémi K; Borkenau, Peter; Borsboom, Denny; Dolan, Conor V

2014-01-01

We address the question of equivalence between modeling results obtained on intra-individual and inter-individual levels of psychometric analysis. Our focus is on the concept of measurement invariance and the role it may play in this context. We discuss this in general against the background of the latent variable paradigm, complemented by an operational demonstration in terms of a linear state-space model, i.e., a time series model with latent variables. Implemented in a multiple-occasion and multiple-subject setting, the model simultaneously accounts for intra-individual and inter-individual differences. We consider the conditions-in terms of invariance constraints-under which modeling results are generalizable (a) over time within subjects, (b) over subjects within occasions, and (c) over time and subjects simultaneously thus implying an equivalence-relationship between both dimensions. Since we distinguish the measurement model from the structural model governing relations between the latent variables of interest, we decompose the invariance constraints into those that involve structural parameters and those that involve measurement parameters and relate to measurement invariance. Within the resulting taxonomy of models, we show that, under the condition of measurement invariance over time and subjects, there exists a form of structural equivalence between levels of analysis that is distinct from full structural equivalence, i.e., ergodicity. We demonstrate how measurement invariance between and within subjects can be tested in the context of high-frequency repeated measures in personality research. Finally, we relate problems of measurement variance to problems of non-ergodicity as currently discussed and approached in the literature.

What’s hampering measurement invariance: Detecting non-invariant items using clusterwise simultaneous component analysis

Directory of Open Access Journals (Sweden)

Kim eDe Roover

2014-06-01

Full Text Available The issue of measurement invariance is ubiquitous in the behavioral sciences nowadays as more and more studies yield multivariate multigroup data. When measurement invariance cannot be established across groups, this is often due to different loadings on only a few items. Within the multigroup CFA framework, methods have been proposed to trace such non-invariant items, but these methods have some disadvantages in that they require researchers to run a multitude of analyses and in that they imply assumptions that are often questionable. In this paper, we propose an alternative strategy which builds on clusterwise simultaneous component analysis (SCA. Clusterwise SCA, being an exploratory technique, assigns the groups under study to a few clusters based on differences and similarities in the covariance matrices, and thus based on the component structure of the items. Non-invariant items can then be traced by comparing the cluster-specific component loadings via congruence coefficients, which is far more parsimonious than comparing the component structure of all separate groups. In this paper we present a heuristic for this procedure. Afterwards, one can return to the multigroup CFA framework and check whether removing the non-invariant items or removing some of the equality restrictions for these items, yields satisfactory invariance test results. An empirical application concerning cross-cultural emotion data is used to demonstrate that this novel approach is useful and can co-exist with the traditional CFA approaches.

Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students.

Science.gov (United States)

Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo; Salinas-Oñate, Natalia; Grunert, Klaus G; Lobos, Germán; Sepúlveda, José; Orellana, Ligia; Hueche, Clementina; Bonilla, Héctor

2017-06-01

This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non-probabilistic longitudinal sampling, 114 university students (65.8% female, mean age: 22.5) completed the SWFL questionnaire three times, over intervals of approximately one year. Confirmatory factor analysis was used to examine longitudinal measurement invariance. Two types of analysis were conducted: first, a longitudinal invariance by time, and second, a multigroup longitudinal invariance by sex, age, socio-economic status and place of residence during the study period. Results showed that the 3-item version of the SWFL exhibited strong longitudinal invariance (equal factor loadings and equal indicator intercepts). Longitudinal multigroup invariance analysis also showed that the 3-item version of the SWFL displays strong invariance by socio-economic status and place of residence during the study period over time. Nevertheless, it was only possible to demonstrate equivalence of the longitudinal factor structure among students of both sexes, and among those older and younger than 22 years. Generally, these findings suggest that the SWFL scale has satisfactory psychometric properties for longitudinal measurement invariance in university students with similar characteristics as the students that participated in this research. It is also possible to suggest that satisfaction with food-related life is associated with sex and age. Copyright © 2017 Elsevier Ltd. All rights reserved.

Freezing and melting line invariants of the Lennard-Jones system

DEFF Research Database (Denmark)

Costigliola, Lorenzo; Schrøder, Thomas; Dyre, Jeppe C.

2016-01-01

The invariance of several structural and dynamical properties of the Lennard-Jones (LJ) system along the freezing and melting lines is interpreted in terms of isomorph theory. First the freezing/melting lines of the LJ system are shown to be approximated by isomorphs. Then we show...... that the invariants observed along the freezing and melting isomorphs are also observed on other isomorphs in the liquid and crystalline phases. The structure is probed by the radial distribution function and the structure factor and dynamics are probed by the mean-square displacement, the intermediate scattering...... function, and the shear viscosity. Studying these properties with reference to isomorph theory explains why the known single-phase melting criteria hold, e.g., the Hansen–Verlet and the Lindemann criteria, and why the Andrade equation for the viscosity at freezing applies, e.g., for most liquid metals. Our...

The measurement invariance of job diagnostic survey (JDS) across three university student groups

Energy Technology Data Exchange (ETDEWEB)

Martinez-Gomez, M.; Marin-Garcia, J.A.; Girado Omeara, M.

2016-07-01

The main purpose of this study is to apply a multigroup confirmatory analysis to examine the measurement invariance (MI) of the adapted version of the Job Diagnosis Survey (JDS) as a measurement tool that analyses the relationship between the features of teaching methodologies with university students’ motivation and satisfaction across data collected on different degrees and academic years. Design/methodology/approach: Confirmatory factor analysis was carried out using a multigroup structural equation model, using the program EQS 6.1 to test the invariance of the adapted version of JDS in a sample constituted by 535 student of a Spanish public university. The assessment of invariance included the levels of configural, metric, scalar, covariance and latent variables invariance. Several goodness-of-fit measures were assessed... (Author)

Invariant probabilities of transition functions

CERN Document Server

Zaharopol, Radu

2014-01-01

The structure of the set of all the invariant probabilities and the structure of various types of individual invariant probabilities of a transition function are two topics of significant interest in the theory of transition functions, and are studied in this book. The results obtained are useful in ergodic theory and the theory of dynamical systems, which, in turn, can be applied in various other areas (like number theory). They are illustrated using transition functions defined by flows, semiflows, and one-parameter convolution semigroups of probability measures. In this book, all results on transition probabilities that have been published by the author between 2004 and 2008 are extended to transition functions. The proofs of the results obtained are new. For transition functions that satisfy very general conditions the book describes an ergodic decomposition that provides relevant information on the structure of the corresponding set of invariant probabilities. Ergodic decomposition means a splitting of t...

Testing the Factorial Invariance of the English and Filipino Versions of the Inventory of School Motivation with Bilingual Students in the Philippines

Science.gov (United States)

Ganotice, Fraide A., Jr.; Bernardo, Allan B. I.; King, Ronnel B.

2012-01-01

The study explored the invariance of Filipino and English versions of the Inventory of School Motivation (ISM) for Filipino-English bilingual students. There was invariance in the factor structure and factor loadings across the two language versions. Between-network construct validation showed consistent associations between ISM-mastery goals and…

Revisiting measurement invariance in intelligence testing in aging research: Evidence for almost complete metric invariance across age groups.

Science.gov (United States)

Sprague, Briana N; Hyun, Jinshil; Molenaar, Peter C M

2017-01-01

Invariance of intelligence across age is often assumed but infrequently explicitly tested. Horn and McArdle (1992) tested measurement invariance of intelligence, providing adequate model fit but might not consider all relevant aspects such as sub-test differences. The goal of the current paper is to explore age-related invariance of the WAIS-R using an alternative model that allows direct tests of age on WAIS-R subtests. Cross-sectional data on 940 participants aged 16-75 from the WAIS-R normative values were used. Subtests examined were information, comprehension, similarities, vocabulary, picture completion, block design, picture arrangement, and object assembly. The two intelligence factors considered were fluid and crystallized intelligence. Self-reported ages were divided into young (16-22, n = 300), adult (29-39, n = 275), middle (40-60, n = 205), and older (61-75, n = 160) adult groups. Results suggested partial metric invariance holds. Although most of the subtests reflected fluid and crystalized intelligence similarly across different ages, invariance did not hold for block design on fluid intelligence and picture arrangement on crystallized intelligence for older adults. Additionally, there was evidence of a correlated residual between information and vocabulary for the young adults only. This partial metric invariance model yielded acceptable model fit compared to previously-proposed invariance models of Horn and McArdle (1992). Almost complete metric invariance holds for a two-factor model of intelligence. Most of the subtests were invariant across age groups, suggesting little evidence for age-related bias in the WAIS-R. However, we did find unique relationships between two subtests and intelligence. Future studies should examine age-related differences in subtests when testing measurement invariance in intelligence.

TEM characterization of invariant line interfaces and structural ledges in a Mo-Si alloy

International Nuclear Information System (INIS)

Xiao, S.Q.; Dahmen, U.; Maloy, S.A.; Heuer, A.H.

1995-06-01

Two distinct lath morphologies of Mo 5 Si 3 precipitates observed in MoSi 2 differ in their cross-sectional shape and lattice orientation. Type I laths exhibit a rectangular cross section, with interfaces parallel to low-index planes, while Type II laths are parallelogram-shaped, with their major interface at 13 degree to the Type I precipitate. The corresponding orientation relationships differ by a 1.8 degree rotation around the lath axis. In this study, the difference between the two characteristic morphologies and orientation relationships is shown to be the formation of an invariant line strain for Type II precipitates. On an atomic scale, both interfaces have a terrace and ledge structure but differ in the stacking sequence of interfacial ledges associated with partial dislocations. The structural unit model and the invariant line model predict identical interface geometries which agree closely with the observations

Relating measurement invariance, cross-level invariance, and multilevel reliability

NARCIS (Netherlands)

Jak, S.; Jorgensen, T.D.

2017-01-01

Data often have a nested, multilevel structure, for example when data are collected from children in classrooms. This kind of data complicate the evaluation of reliability and measurement invariance, because several properties can be evaluated at both the individual level and the cluster level, as

The component structure of conformal supergravity invariants in six dimensions

Energy Technology Data Exchange (ETDEWEB)

Butter, Daniel [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); George and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University,College Station, TX 77843 (United States); Novak, Joseph [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, D-14476 Golm (Germany); Tartaglino-Mazzucchelli, Gabriele [Instituut voor Theoretische Fysica, KU Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium)

2017-05-24

In the recent paper https://arxiv.org/abs/1606.02921, the two invariant actions for 6D N=(1,0) conformal supergravity were constructed in superspace, corresponding to the supersymmetrization of C{sup 3} and C◻C. In this paper, we provide the translation from superspace to the component formulation of superconformal tensor calculus, and we give the full component actions of these two invariants. As a second application, we build the component form for the supersymmetric F◻F action coupled to conformal supergravity. Exploiting the fact that the N=(2,0) Weyl multiplet has a consistent truncation to N=(1,0), we then verify that there is indeed only a single N=(2,0) conformal supergravity invariant and reconstruct most of its bosonic terms by uplifting a certain linear combination of N=(1,0) invariants.

Translational invariance in bag model

International Nuclear Information System (INIS)

Megahed, F.

1981-10-01

In this thesis, the effect of restoring the translational invariance to an approximation to the MIT bag model on the calculation of deep inelastic structure functions is investigated. In chapter one, the model and its major problems are reviewed and Dirac's method of quantisation is outlined. This method is used in chapter two to quantise a two-dimensional complex scalar bag and formal expressions for the form factor and the structure functions are obtained. In chapter three, the expression for the structure function away from the Bjorken limit is studied. The corrections to the L 0 - approximation to the structure function is calculated in chapter four and it is shown to be large. Finally, in chapter five, a bag-like model for kinematic corrections to structure functions is introduced and agreement with data between 2 and 6 (GeV/C) 2 is obtained. (author)

Embedded graph invariants in Chern-Simons theory

International Nuclear Information System (INIS)

Major, Seth A.

1999-01-01

Chern-Simons gauge theory, since its inception as a topological quantum field theory, has proved to be a rich source of understanding for knot invariants. In this work the theory is used to explore the definition of the expectation value of a network of Wilson lines -- an embedded graph invariant. Using a generalization of the variational method, lowest-order results for invariants for graphs of arbitrary valence and general vertex tangent space structure are derived. Gauge invariant operators are introduced. Higher order results are found. The method used here provides a Vassiliev-type definition of graph invariants which depend on both the embedding of the graph and the group structure of the gauge theory. It is found that one need not frame individual vertices. However, without a global projection of the graph there is an ambiguity in the relation of the decomposition of distinct vertices. It is suggested that framing may be seen as arising from this ambiguity -- as a way of relating frames at distinct vertices

Measurement and structural invariance of the US version of the Birth Satisfaction Scale-Revised (BSS-R) in a large sample.

Science.gov (United States)

Martin, Colin R; Hollins Martin, Caroline J; Burduli, Ekaterina; Barbosa-Leiker, Celestina; Donovan-Batson, Colleen; Fleming, Susan E

2017-08-01

The 10-item Birth Satisfaction Scale-Revised (BSS-R) is being increasingly used internationally. The use of the measure and the concept has gathered traction in the United States following the development of a US version of the tool. A limitation of previous studies of the measurement characteristics of the BSS-R is modest sample size. Unplanned pregnancy is recognised as being associated with a range of negative birth outcomes, but the relationship to birth satisfaction has received little attention, despite the importance of birth satisfaction to a range of postnatal outcomes. The current investigation sought to evaluate the measurement characteristics of the BSS-R in a large postpartum sample. Multiple Groups Confirmatory Factor Analysis (MGCFA) was used to evaluate a series of measurement and structural models of the BSS-R to evaluate fundamental invariance characteristics using planned/unplanned pregnancy status to differentiate groups. Complete data from N=2116 women revealed that the US version of the BSS-R offers an excellent fit to data and demonstrates full measurement and structural invariance. Little difference was observed between women on the basis of planned/unplanned pregnancy stratification on measures of birth satisfaction. The established relationship between unplanned pregnancy and negative perinatal outcomes was not found to extend to birth satisfaction in the current study. The BSS-R demonstrated exemplary measurement and structural invariance characteristics. The current study strongly supports the use of the US version of the BSS-R to compare birth satisfaction across different groups of women with theoretical and measurement confidence. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Factor Structure and Gender Stability of the Brazilian Version of the Pornography Consumption Inventory.

Science.gov (United States)

Baltieri, Danilo Antonio; de Oliveira, Vitor Henrique; de Souza Gatti, Ana Luísa; Junqueira Aguiar, Ana Saito; de Souza Aranha E Silva, Renata Almeida

2016-10-02

There are a few instruments available to measure pornograhy consumption-related constructs, and this lack of instruments can compromise the validity of research findings. The Pornography Consumption Inventory (PCI) assesses four motivations for pornography consumption, and it has been validated in hypersexual men and medical students. However, whether the psychometric properties of this instrument are comparable across genders remains unclear. Multigroup confirmatory factor analysis (MGCFA) was used to verify the invariance of the structure of the PCI across male (100) and female (105) university students. The confirmatory factor analysis (CFA) for each group showed a reasonably good fit of the data to the four-factor model. The MGCFA model included only factor loadings constrained to be equal between both genders (ΔCFI 0.05). However, the ΔCFI did not support a strong and strict factorial invariance, ΔCFI > 0.01. Although both genders seemed to agree with the conceptualization of pornography and motivations for consuming it, the PCI was not gender-invariant, as men showed a stronger degree of motivation to consume pornographic material than women did. The implications of these findings regarding the measurement of motivations for pornography use are outlined.

Psychometric evaluation of the Overexcitability Questionnaire-Two applying Bayesian Structural Equation Modeling (BSEM and multiple-group BSEM-based alignment with approximate measurement invariance

Directory of Open Access Journals (Sweden)

Niki eDe Bondt

2015-12-01

Full Text Available The Overexcitability Questionnaire-Two (OEQ-II measures the degree and nature of overexcitability, which assists in determining the developmental potential of an individual according to Dabrowski’s Theory of Positive Disintegration. Previous validation studies using frequentist confirmatory factor analysis, which postulates exact parameter constraints, led to model rejection and a long series of model modifications. Bayesian structural equation modeling (BSEM allows the application of zero-mean, small-variance priors for cross-loadings, residual covariances, and differences in measurement parameters across groups, better reflecting substantive theory and leading to better model fit and less overestimation of factor correlations. Our BSEM analysis with a sample of 516 students in higher education yields positive results regarding the factorial validity of the OEQ-II. Likewise, applying BSEM-based alignment with approximate measurement invariance, the absence of non-invariant factor loadings and intercepts across gender is supportive of the psychometric quality of the OEQ-II. Compared to males, females scored significantly higher on emotional and sensual overexcitability, and significantly lower on psychomotor overexcitability.

The Chinese Family Assessment Instrument (C-FAI): Hierarchical Confirmatory Factor Analyses and Factorial Invariance

Science.gov (United States)

Shek, Daniel T. L.; Ma, Cecilia M. S.

2010-01-01

Objective: This paper examines the dimensionality and factorial invariance of the Chinese Family Assessment Instrument (C-FAI) using multigroup confirmatory factor analyses (MCFAs). Method: A total of 3,649 students responded to the C-FAI in a community survey. Results: Results showed that there are five dimensions of the C-FAI (communication,…

Cross-Cultural Invariance of the Mental Toughness Inventory Among Australian, Chinese, and Malaysian Athletes: A Bayesian Estimation Approach.

Science.gov (United States)

Gucciardi, Daniel F; Zhang, Chun-Qing; Ponnusamy, Vellapandian; Si, Gangyan; Stenling, Andreas

2016-04-01

The aims of this study were to assess the cross-cultural invariance of athletes' self-reports of mental toughness and to introduce and illustrate the application of approximate measurement invariance using Bayesian estimation for sport and exercise psychology scholars. Athletes from Australia (n = 353, Mage = 19.13, SD = 3.27, men = 161), China (n = 254, Mage = 17.82, SD = 2.28, men = 138), and Malaysia (n = 341, Mage = 19.13, SD = 3.27, men = 200) provided a cross-sectional snapshot of their mental toughness. The cross-cultural invariance of the mental toughness inventory in terms of (a) the factor structure (configural invariance), (b) factor loadings (metric invariance), and (c) item intercepts (scalar invariance) was tested using an approximate measurement framework with Bayesian estimation. Results indicated that approximate metric and scalar invariance was established. From a methodological standpoint, this study demonstrated the usefulness and flexibility of Bayesian estimation for single-sample and multigroup analyses of measurement instruments. Substantively, the current findings suggest that the measurement of mental toughness requires cultural adjustments to better capture the contextually salient (emic) aspects of this concept.

Conformal invariance in supergravity

International Nuclear Information System (INIS)

Bergshoeff, E.A.

1983-01-01

In this thesis the author explains the role of conformal invariance in supergravity. He presents the complete structure of extended conformal supergravity for N <= 4. The outline of this work is as follows. In chapter 2 he briefly summarizes the essential properties of supersymmetry and supergravity and indicates the use of conformal invariance in supergravity. The idea that the introduction of additional symmetry transformations can make clear the structure of a field theory is not reserved to supergravity only. By means of some simple examples it is shown in chapter 3 how one can always introduce additional gauge transformations in a theory of massive vector fields. Moreover it is shown how the gauge invariant formulation sometimes explains the quantum mechanical properties of the theory. In chapter 4 the author defines the conformal transformations and summarizes their main properties. He explains how these conformal transformations can be used to analyse the structure of gravity. The supersymmetric extension of these results is discussed in chapter 5. Here he describes as an example how N=1 supergravity can be reformulated in a conformally-invariant way. He also shows that beyond N=1 the gauge fields of the superconformal symmetries do not constitute an off-shell field representation of extended conformal supergravity. Therefore, in chapter 6, a systematic method to construct the off-shell formulation of all extended conformal supergravity theories with N <= 4 is developed. As an example he uses this method to construct N=1 conformal supergravity. Finally, in chapter 7 N=4 conformal supergravity is discussed. (Auth.)

Measurement invariance of the Belief in a Zero-Sum Game scale across 36 countries.

Science.gov (United States)

Różycka-Tran, Joanna; Jurek, Paweł; Olech, Michał; Piotrowski, Jarosław; Żemojtel-Piotrowska, Magdalena

2017-11-28

In this paper, we examined the psychometric properties of cross-cultural validation and replicability (i.e. measurement invariance) of the Belief in a Zero-Sum Game (BZSG) scale, measuring antagonistic belief about interpersonal relations over scarce resources. The factorial structure of the BZSG scale was investigated in student samples from 36 countries (N = 9907), using separate confirmatory factor analyses (CFAs) for each country. The cross-cultural validation of the scale was based on multigroup confirmatory factor analyses (MGCFA). The results confirmed that the scale had a one-factor structure in all countries, in which configural and metric invariance between countries was confirmed. As a zero-sum belief about social relations perceived as antagonistic, BZSG is an important factor related to, for example, social and international relations, attitudes toward immigrants, or well-being. The paper proposes different uses of the BZSG scale for cross-cultural studies in different fields of psychology: social, political, or economic. © 2017 International Union of Psychological Science.

Measuring social desirability across language and sex: A comparison of Marlowe-Crowne Social Desirability Scale factor structures in English and Mandarin Chinese in Malaysia.

Science.gov (United States)

Kurz, A Solomon; Drescher, Christopher F; Chin, Eu Gene; Johnson, Laura R

2016-06-01

Malaysia is a Southeast Asian country in which multiple languages are prominently spoken, including English and Mandarin Chinese. As psychological science continues to develop within Malaysia, there is a need for psychometrically sound instruments that measure psychological phenomena in multiple languages. For example, assessment tools for measuring social desirability could be a useful addition in psychological assessments and research studies in a Malaysian context. This study examined the psychometric performance of the English and Mandarin Chinese versions of the Marlowe-Crowne Social Desirability Scale when used in Malaysia. Two hundred and eighty-three students (64% female; 83% Chinese, 9% Indian) from two college campuses completed the Marlowe-Crowne Social Desirability Scale in their language of choice (i.e., English or Mandarin Chinese). Proposed factor structures were compared with confirmatory factor analysis, and multiple indicators-multiple causes models were used to examine measurement invariance across language and sex. Factor analyses supported a two-factor structure (i.e., Attribution and Denial) for the measure. Invariance tests revealed the scale was invariant by sex, indicating that social desirability can be interpreted similarly across sex. The scale was partially invariant by language version, with some non-invariance observed within the Denial factor. Non-invariance may be related to differences in the English and Mandarin Chinese languages, as well as cultural differences. Directions for further research include examining the measurement of social desirability in other contexts where both English and Mandarin Chinese are spoken (i.e., China) and further examining the causes of non-invariance on specific items. © 2016 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Factor structure and psychometric properties of a Romanian translation of the Body Appreciation Scale-2.

Science.gov (United States)

Swami, Viren; Tudorel, Otilia; Goian, Cosmin; Barron, David; Vintila, Mona

2017-12-01

We examined the psychometric properties of a Romanian translation of the 10-item Body Appreciation Scale-2 (BAS-2). A total of 453 university students from Romania completed the BAS-2, along with measures of disordered eating, self-esteem, satisfaction with life, and subjective happiness. In addition, a separate sample of university students (N=109) completed only the BAS-2 at two time-points three weeks apart. Principal-axis factor analysis indicated that BAS-2 scores had a one-dimensional factor structure in both women and men. Confirmatory factor analysis indicated that this factor structure had adequate fit, but invariance across sex was not supported. Further analyses indicated that BAS-2 scores evidenced internal consistency, convergent validity, and test-retest reliability in both women and men. These results suggest that BAS-2 scores reduce to one dimension in Romanian adults, but the lack of sex invariance may indicate that the same latent construct is not being measured in women and men. Copyright © 2017 Elsevier Ltd. All rights reserved.

Turkish Version of the Survey of Attitudes toward Statistics: Factorial Structure Invariance by Gender

Science.gov (United States)

Sarikaya, Esma Emmioglu; Ok, Ahmet; Aydin, Yesim Capa; Schau, Candace

2018-01-01

This study examines factorial structure and the gender invariance of the Turkish version of the Survey of Attitudes toward Statistics (SATS-36). The SATS-36 has 36 items measuring six components: affect, cognitive competence, value, difficulty, effort, and interest. Data were collected from 347 university students. Results showed that the Turkish…

EMPLOYEE COMMITMENT ACROSS COUNTRIES AND TIMES - MEASUREMENT INVARIANCE

Directory of Open Access Journals (Sweden)

Dana Mesner Andolšek

2015-01-01

Full Text Available Employee organisational commitment has been long and extensively studied until now (Meyer & Allen, 1997; Jaussi, 2007.An emphasis of current analysis was to verify its measurement characteristics, for the purpose of comparisons of levels of commitment across time and countries. A limited set of countries was chosen among those available in a sample from the data on Work Orientations II, ISSP 1997, purpose fully selected to reflect cultural and structural differences that was expected to affect change in levels of organisational commitment. With the use of structural equations models we first confirmed that a model for configural invariance for two factors measuring conceptually distinct components of Affective commitment (AC and Continuance commitment (CC respectively has better support than of one factor model. Metric and error term invariance was subsequently confirmed. Scalar equivalence, needed for valid comparison of mean levels of both components of commitment, was confirmed as well, with the exception of two country specific Tau coefficient. Finally, a model thus established was applied additionally on data from2005 ISSP. Acceptable fit was achieved for a common model containing both points in time and all countries, which allowed making more firm conclusions about the changes in AC and CC in different countries.

The Learning and Study Strategies Inventory-High School Version: Issues of Factorial Invariance Across Gender and Ethnicity

Science.gov (United States)

Stevens, Tara; Tallent-Runnels, Mary K.

2004-01-01

The purpose of this study was to investigate the latent structure of the Learning and Study Strategies Inventory-High School (LASSI-HS) through confirmatory factor analysis and factorial invariance models. A simple modification of the three-factor structure was considered. Using a larger sample, cross-validation was completed and the equality of…

Factor structure of DSM-5 PTSD symptoms in trauma-exposed adolescents: Examining stability across time.

Science.gov (United States)

Wang, Li; Cao, Xing; Cao, Chengqi; Fang, Ruojiao; Yang, Haibo; Elhai, Jon D

2017-12-01

This study investigated the latent structure of DSM-5 PTSD symptoms using two-wave longitudinal data collected from a sample of adolescents exposed to an explosion accident. Two waves of surveys were conducted approximately 3 and 8 months after the accident, respectively. A total of 836 students completed the baseline survey, and 762 students completed the follow-up survey. The results of confirmatory factor analyses(CFA) indicated that a seven-factor hybrid model composed of intrusion, avoidance, negative affect, anhedonia, externalizing behaviors, anxious arousal and dysphoric arousal factors yielded significantly better data fit at both waves than the other models including the DSM-5 four-factor model, the six-factor anhedonia and externalizing behaviors models. Furthermore, the results of CFA invariance tests supported the longitudinal invariance of the model. Implications and limitations in terms of these results are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Invariance Signatures: Characterizing contours by their departures from invariance

OpenAIRE

Squire, David; Caelli, Terry M.

1997-01-01

In this paper, a new invariant feature of two-dimensional contours is reported: the Invariance Signature. The Invariance Signature is a measure of the degree to which a contour is invariant under a variety of transformations, derived from the theory of Lie transformation groups. It is shown that the Invariance Signature is itself invariant under shift, rotation and scaling of the contour. Since it is derived from local properties of the contour, it is well-suited to a neural network implement...

Psychometric Properties and Measurement Invariance of the Brief Symptom Inventory-18 Among Chinese Insurance Employees

Directory of Open Access Journals (Sweden)

Mingshu Li

2018-04-01

Full Text Available This study aimed to examine the psychometric properties and factorial invariance of the Brief Symptom Inventory-18 (BSI-18. Confirmatory factor analyses (CFAs were performed to verify the BSI-18’s factor structure in a large sample of Chinese insurance professionals (N = 2363, 62.7% women; age range = 19–70. Multigroup CFA were performed to test the measurement invariance of the model with the best fit across genders. In addition, structural equation modeling was conducted to test the correlations between the BSI-18 and two covariates – social support perception and grit trait. Results indicated that the bi-factor model best fit the data and was also equivalent across genders. The BSI-18’s general factor, and somatization and depression dimensions were significantly related to social support perception and grit trait, whereas the anxiety dimension was not. Overall, our findings suggested that the BSI-18’s can be a promising tool in assessing general psychological distress in Chinese employees.

Object recognition by implicit invariants

Czech Academy of Sciences Publication Activity Database

Flusser, Jan; Kautsky, J.; Šroubek, Filip

2007-01-01

Roč. 2007, č. 4673 (2007), s. 856-863 ISSN 0302-9743. [Computer Analysis of Images and Patterns. Vienna, 27.08.2007-29.08.2007] R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Invariants * implicit invariants * moments * orthogonal polynomials * nonlinear object deformation Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.402, year: 2005 http:// staff .utia.cas.cz/sroubekf/papers/CAIP_07.pdf

Normal Anti-Invariant Submanifolds of Paraquaternionic Kähler Manifolds

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Novac-Claudiu Chiriac

2006-12-01

Full Text Available We introduce normal anti-invariant submanifolds of paraquaternionic Kähler manifolds and study the geometric structures induced on them. We obtain necessary and sufficient conditions for the integrability of the distributions defined on a normal anti-invariant submanifold. Also, we present characterizations of local (global anti-invariant products.

Teen Dating Violence, Sexual Harassment, and Bullying Among Middle School Youth: Examining Measurement Invariance by Gender.

Science.gov (United States)

Cutbush, Stacey; Williams, Jason

2016-12-01

This study investigated measurement invariance by gender among commonly used teen dating violence (TDV), sexual harassment, and bullying measures. Data were collected from one cohort of seventh-grade middle school students (N = 754) from four schools. Using structural equation modeling, exploratory and confirmatory factor analyses assessed measurement models and tested measurement invariance by gender for aggression measures. Analyses invoked baseline data only. Physical and psychological TDV perpetration measures achieved strict measurement invariance, while bullying perpetration demonstrated partial strict invariance. Electronic TDV and sexual harassment perpetration achieved metric/scalar invariance. Study findings lend validation to prior and future studies using these measures with similar populations. Future research should increase attention to measurement development, refinement, and testing among study measures. © 2016 The Authors. Journal of Research on Adolescence © 2016 Society for Research on Adolescence.

Electric dipole moments with and beyond flavor invariants

Science.gov (United States)

Smith, Christopher; Touati, Selim

2017-11-01

In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino masses. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. Finally, the formalism is adapted to deal with a third class of flavor structures, sensitive to the flavored U (1) phases, and used to study the impact of the strong CP-violating interaction and the interplay between the neutrino Majorana phases and possible baryon and/or lepton number violating interactions.

Electric dipole moments with and beyond flavor invariants

Directory of Open Access Journals (Sweden)

Christopher Smith

2017-11-01

Full Text Available In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino masses. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. Finally, the formalism is adapted to deal with a third class of flavor structures, sensitive to the flavored U(1 phases, and used to study the impact of the strong CP-violating interaction and the interplay between the neutrino Majorana phases and possible baryon and/or lepton number violating interactions.

Confirmatory Factor Analysis of the Bases of Leader Power: First-Order Factor Model and Its Invariance Across Groups.

Science.gov (United States)

Rahim, M A; Magner, N R

1996-10-01

Confirmatory factor analyses of data (from five samples: N = 308 accountants and finance professionals, N = 578 management and non-management employees, and N = 588 employed management students in the U.S.; N = 728 management and non-management employees in S. Korea, N = 250 management and non-management bank employees in Bangladesh) on the 29 items of the Rahim Leader Power Inventory were performed with LISREL 7. The results provided support for the convergent and discriminant validities of the subscales measuring the five bases of leader power (coercive, reward, legitimate, expert, and referent), and the invariance of factor pattern and factor loadings across organizational levels and the three American samples. Additional analysis indicated that leader power profiles differed across the three national cultures represented in the study.

Permutation-invariant distance between atomic configurations

Science.gov (United States)

Ferré, Grégoire; Maillet, Jean-Bernard; Stoltz, Gabriel

2015-09-01

We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity.

Permutation-invariant distance between atomic configurations

International Nuclear Information System (INIS)

Ferré, Grégoire; Maillet, Jean-Bernard; Stoltz, Gabriel

2015-01-01

We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity

The Quest for Comparability: Studying the Invariance of the Teachers’ Sense of Self-Efficacy (TSES) Measure across Countries

Science.gov (United States)

Scherer, Ronny; Jansen, Malte; Nilsen, Trude; Areepattamannil, Shaljan; Marsh, Herbert W.

2016-01-01

Teachers’ self-efficacy is an important motivational construct that is positively related to a variety of outcomes for both the teachers and their students. This study addresses challenges associated with the commonly used ‘Teachers’ Sense of Self-Efficacy (TSES)’ measure across countries and provides a synergism between substantive research on teachers’ self-efficacy and the novel methodological approach of exploratory structural equation modeling (ESEM). These challenges include adequately representing the conceptual overlap between the facets of self-efficacy in a measurement model (cross-loadings) and comparing means and factor structures across countries (measurement invariance). On the basis of the OECD Teaching and Learning International Survey (TALIS) 2013 data set comprising 32 countries (N = 164,687), we investigate the effects of cross-loadings in the TSES measurement model on the results of measurement invariance testing and the estimation of relations to external constructs (i.e., working experience, job satisfaction). To further test the robustness of our results, we replicate the 32-countries analyses for three selected sub-groups of countries (i.e., Nordic, East and South-East Asian, and Anglo-Saxon country clusters). For each of the TALIS 2013 participating countries, we found that the factor structure of the self-efficacy measure is better represented by ESEM than by confirmatory factor analysis (CFA) models that do not allow for cross-loadings. For both ESEM and CFA, only metric invariance could be achieved. Nevertheless, invariance levels beyond metric invariance are better achieved with ESEM within selected country clusters. Moreover, the existence of cross-loadings did not affect the relations between the dimensions of teachers’ self-efficacy and external constructs. Overall, this study shows that a conceptual overlap between the facets of self-efficacy exists and can be well-represented by ESEM. We further argue for the cross

The Quest for Comparability: Studying the Invariance of the Teachers' Sense of Self-Efficacy (TSES) Measure across Countries.

Science.gov (United States)

Scherer, Ronny; Jansen, Malte; Nilsen, Trude; Areepattamannil, Shaljan; Marsh, Herbert W

2016-01-01

Teachers' self-efficacy is an important motivational construct that is positively related to a variety of outcomes for both the teachers and their students. This study addresses challenges associated with the commonly used 'Teachers' Sense of Self-Efficacy (TSES)' measure across countries and provides a synergism between substantive research on teachers' self-efficacy and the novel methodological approach of exploratory structural equation modeling (ESEM). These challenges include adequately representing the conceptual overlap between the facets of self-efficacy in a measurement model (cross-loadings) and comparing means and factor structures across countries (measurement invariance). On the basis of the OECD Teaching and Learning International Survey (TALIS) 2013 data set comprising 32 countries (N = 164,687), we investigate the effects of cross-loadings in the TSES measurement model on the results of measurement invariance testing and the estimation of relations to external constructs (i.e., working experience, job satisfaction). To further test the robustness of our results, we replicate the 32-countries analyses for three selected sub-groups of countries (i.e., Nordic, East and South-East Asian, and Anglo-Saxon country clusters). For each of the TALIS 2013 participating countries, we found that the factor structure of the self-efficacy measure is better represented by ESEM than by confirmatory factor analysis (CFA) models that do not allow for cross-loadings. For both ESEM and CFA, only metric invariance could be achieved. Nevertheless, invariance levels beyond metric invariance are better achieved with ESEM within selected country clusters. Moreover, the existence of cross-loadings did not affect the relations between the dimensions of teachers' self-efficacy and external constructs. Overall, this study shows that a conceptual overlap between the facets of self-efficacy exists and can be well-represented by ESEM. We further argue for the cross

Multiperiod Maximum Loss is time unit invariant.

Science.gov (United States)

Kovacevic, Raimund M; Breuer, Thomas

2016-01-01

Time unit invariance is introduced as an additional requirement for multiperiod risk measures: for a constant portfolio under an i.i.d. risk factor process, the multiperiod risk should equal the one period risk of the aggregated loss, for an appropriate choice of parameters and independent of the portfolio and its distribution. Multiperiod Maximum Loss over a sequence of Kullback-Leibler balls is time unit invariant. This is also the case for the entropic risk measure. On the other hand, multiperiod Value at Risk and multiperiod Expected Shortfall are not time unit invariant.

The measurement invariance of job diagnostic survey (JDS across three university student groups

Directory of Open Access Journals (Sweden)

Monica Martinez-Gomez

2016-02-01

Full Text Available Purpose: The main purpose of this study is to apply a multigroup confirmatory analysis to examine the measurement invariance (MI of the adapted version of the Job Diagnosis Survey (JDS as a measurement tool that analyses the relationship between the features of teaching methodologies with university students’ motivation and satisfaction across data collected on different degrees and academic years. Design/methodology/approach: Confirmatory factor analysis was carried out using a multigroup structural equation model, using the program EQS 6.1 to test the invariance of the adapted version of JDS in a sample constituted by 535 student of a Spanish public university. The assessment of invariance included the levels of configural, metric, scalar, covariance and latent variables invariance. Several goodness-of-fit measures were assessed. Findings: The results show that measurements are equivalent at the configural, metric, covariance and latent factors invariance. Although the hypotheses of scalar invariance is rejected, results suggest that JDS is partial strict invariant and has satisfactory psychometric properties on all samples. Research limitations/implications: The sample is framed in university students aged between 18 and 30 and for a questionnaire on teaching methodology and students' satisfaction in the context of a Spanish university and the generalization to other questionnaire, or population, should be proved with specific data. Furthermore, the sample size is rather small. Originality/value: In the current process of change that is taking place in universities according to the plan developed by the European Space of Higher Education, focused on increasing the student skills, validate instruments as the satisfaction scale of JDS, are necessary to evaluate students’ satisfaction with new active methodologies. These findings are useful for researchers since they add the first sample in which the MI of a student’s satisfaction survey

Reynolds number invariance of the structure inclination angle in wall turbulence.

Science.gov (United States)

Marusic, Ivan; Heuer, Weston D C

2007-09-14

Cross correlations of the fluctuating wall-shear stress and the streamwise velocity in the logarithmic region of turbulent boundary layers are reported over 3 orders of magnitude change in Reynolds number. These results are obtained using hot-film and hot-wire anemometry in a wind tunnel facility, and sonic anemometers and a purpose-built wall-shear stress sensor in the near-neutral atmospheric surface layer on the salt flats of Utah's western desert. The direct measurement of fluctuating wall-shear stress in the atmospheric surface layer has not been available before. Structure inclination angles are inferred from the cross correlation results and are found to be invariant over the large range of Reynolds number. The findings justify the prior use of low Reynolds number experiments for obtaining structure angles for near-wall models in the large-eddy simulation of atmospheric surface layer flows.

Invariant functionals in higher-spin theory

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M.A. Vasiliev

2017-03-01

Full Text Available A new construction for gauge invariant functionals in the nonlinear higher-spin theory is proposed. Being supported by differential forms closed by virtue of the higher-spin equations, invariant functionals are associated with central elements of the higher-spin algebra. In the on-shell AdS4 higher-spin theory we identify a four-form conjectured to represent the generating functional for 3d boundary correlators and a two-form argued to support charges for black hole solutions. Two actions for 3d boundary conformal higher-spin theory are associated with the two parity-invariant higher-spin models in AdS4. The peculiarity of the spinorial formulation of the on-shell AdS3 higher-spin theory, where the invariant functional is supported by a two-form, is conjectured to be related to the holomorphic factorization at the boundary. The nonlinear part of the star-product function F⁎(B(x in the higher-spin equations is argued to lead to divergencies in the boundary limit representing singularities at coinciding boundary space–time points of the factors of B(x, which can be regularized by the point splitting. An interpretation of the RG flow in terms of proposed construction is briefly discussed.

Invariant subspaces

CERN Document Server

Radjavi, Heydar

2003-01-01

This broad survey spans a wealth of studies on invariant subspaces, focusing on operators on separable Hilbert space. Largely self-contained, it requires only a working knowledge of measure theory, complex analysis, and elementary functional analysis. Subjects include normal operators, analytic functions of operators, shift operators, examples of invariant subspace lattices, compact operators, and the existence of invariant and hyperinvariant subspaces. Additional chapters cover certain results on von Neumann algebras, transitive operator algebras, algebras associated with invariant subspaces,

Measurement invariance versus selection invariance: Is fair selection possible?

NARCIS (Netherlands)

Borsboom, D.; Romeijn, J.W.; Wicherts, J.M.

2008-01-01

This article shows that measurement invariance (defined in terms of an invariant measurement model in different groups) is generally inconsistent with selection invariance (defined in terms of equal sensitivity and specificity across groups). In particular, when a unidimensional measurement

Measurement invariance versus selection invariance : Is fair selection possible?

NARCIS (Netherlands)

Borsboom, Denny; Romeijn, Jan-Willem; Wicherts, Jelte M.

This article shows that measurement invariance (defined in terms of an invariant measurement model in different groups) is generally inconsistent with selection invariance (defined in terms of equal sensitivity and specificity across groups). In particular, when a unidimensional measurement

Longitudinal Factor Structure of General Self-Concept and Locus of Control among High School Students

Science.gov (United States)

Wang, Ze; Su, Ihui

2013-01-01

This study examined the longitudinal factor structure of general self-concept and locus of control among high school students over a 4-year period, with data from the National Educational Longitudinal Study of 1988. Measurement invariance was tested over time and across gender and ethnic groups; second-order piecewise latent growth models were…

On asymptotics and resurgent structures of enumerative Gromov-Witten invariants

International Nuclear Information System (INIS)

Couso-Santamaria, Ricardo; Schiappa, Ricardo; Geneve Univ.; Vaz, Ricardo; DESY Hamburg

2016-05-01

Making use of large-order techniques in asymptotics and resurgent analysis, this work addresses the growth of enumerative Gromov-Witten invariants - in their dependence upon genus and degree of the embedded curve - for several different threefold Calabi-Yau toric-varieties. In particular, while the leading asymptotics of these invariants at large genus or at large degree is exponential, at combined large genus and degree it turns out to be factorial. This factorial growth has a resurgent nature, originating via mirror symmetry from the resurgent-transseries description of the B-model free energy. This implies the existence of nonperturbative sectors controlling the asymptotics of the Gromov-Witten invariants, which could themselves have an enumerative-geometry interpretation. The examples addressed include: the resolved conifold; the local surfaces local P 2 and local P 1 x P 1 ; the local curves and Hurwitz theory; and the compact quintic. All examples suggest very rich interplays between resurgent asymptotics and enumerative problems in algebraic geometry.

On asymptotics and resurgent structures of enumerative Gromov-Witten invariants

Energy Technology Data Exchange (ETDEWEB)

Couso-Santamaria, Ricardo [Lisboa Univ. (Portugal). Inst. Superior Tecnico (IST); Schiappa, Ricardo [Lisboa Univ. (Portugal). Inst. Superior Tecnico (IST); Geneve Univ. (Switzerland). Dept. de Physique Theoretique et Section de Mathematiques; Vaz, Ricardo [Lisboa Univ. (Portugal). Inst. Superior Tecnico (IST); DESY Hamburg (Germany). Theory Group

2016-05-15

Making use of large-order techniques in asymptotics and resurgent analysis, this work addresses the growth of enumerative Gromov-Witten invariants - in their dependence upon genus and degree of the embedded curve - for several different threefold Calabi-Yau toric-varieties. In particular, while the leading asymptotics of these invariants at large genus or at large degree is exponential, at combined large genus and degree it turns out to be factorial. This factorial growth has a resurgent nature, originating via mirror symmetry from the resurgent-transseries description of the B-model free energy. This implies the existence of nonperturbative sectors controlling the asymptotics of the Gromov-Witten invariants, which could themselves have an enumerative-geometry interpretation. The examples addressed include: the resolved conifold; the local surfaces local P{sup 2} and local P{sup 1} x P{sup 1}; the local curves and Hurwitz theory; and the compact quintic. All examples suggest very rich interplays between resurgent asymptotics and enumerative problems in algebraic geometry.

Maxwell equations in conformal invariant electrodynamics

International Nuclear Information System (INIS)

Fradkin, E.S.; AN SSSR, Novosibirsk. Inst. Avtomatiki i Ehlektrometrii); Kozhevnikov, A.A.; Palchik, M.Ya.; Pomeransky, A.A.

1983-01-01

We consider a conformal invariant formulation of quantum electrodynamics. Conformal invariance is achieved with a specific mathematical construction based on the indecomposable representations of the conformal group associated with the electromagnetic potential and current. As a corolary of this construction modified expressions for the 3-point Green functions are obtained which both contain transverse parts. They make it possible to formulate a conformal invariant skeleton perturbation theory. It is also shown that the Euclidean Maxwell equations in conformal electrodynamics are manifestations of its kinematical structure: in the case of the 3-point Green functions these equations follow (up to constants) from the conformal invariance while in the case of higher Green functions they are equivalent to the equality of the kernels of the partial wave expansions. This is the manifestation of the mathematical fast of a (partial) equivalence of the representations associated with the potential, current and the field tensor. (orig.)

Phenomenology of local scale invariance: from conformal invariance to dynamical scaling

International Nuclear Information System (INIS)

Henkel, Malte

2002-01-01

Statistical systems displaying a strongly anisotropic or dynamical scaling behaviour are characterized by an anisotropy exponent θ or a dynamical exponent z. For a given value of θ (or z), we construct local scale transformations, which can be viewed as scale transformations with a space-time-dependent dilatation factor. Two distinct types of local scale transformations are found. The first type may describe strongly anisotropic scaling of static systems with a given value of θ, whereas the second type may describe dynamical scaling with a dynamical exponent z. Local scale transformations act as a dynamical symmetry group of certain non-local free-field theories. Known special cases of local scale invariance are conformal invariance for θ=1 and Schroedinger invariance for θ=2. The hypothesis of local scale invariance implies that two-point functions of quasi primary operators satisfy certain linear fractional differential equations, which are constructed from commuting fractional derivatives. The explicit solution of these yields exact expressions for two-point correlators at equilibrium and for two-point response functions out of equilibrium. A particularly simple and general form is found for the two-time auto response function. These predictions are explicitly confirmed at the uniaxial Lifshitz points in the ANNNI and ANNNS models and in the aging behaviour of simple ferromagnets such as the kinetic Glauber-Ising model and the kinetic spherical model with a non-conserved order parameter undergoing either phase-ordering kinetics or non-equilibrium critical dynamics

Projective moment invariants

Czech Academy of Sciences Publication Activity Database

Suk, Tomáš; Flusser, Jan

2004-01-01

Roč. 26, č. 10 (2004), s. 1364-1367 ISSN 0162-8828 R&D Projects: GA ČR GA201/03/0675 Institutional research plan: CEZ:AV0Z1075907 Keywords : projective transform * moment invariants * object recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.352, year: 2004 http://library.utia.cas.cz/prace/20040112.pdf

The Oswestry Disability Index, confirmatory factor analysis in a sample of 35,263 verifies a one-factor structure but practicality issues remain.

Science.gov (United States)

Gabel, Charles Philip; Cuesta-Vargas, Antonio; Qian, Meihua; Vengust, Rok; Berlemann, Ulrich; Aghayev, Emin; Melloh, Markus

2017-08-01

To analyze the factor structure of the Oswestry Disability Index (ODI) in a large symptomatic low back pain (LBP) population using exploratory (EFA) and confirmatory factor analysis (CFA). Analysis of pooled baseline ODI LBP patient data from the international Spine Tango registry of EUROSPINE, the Spine Society of Europe. The sample, with n = 35,263 (55.2% female; age 15-99, median 59 years), included 76.1% of patients with a degenerative disease, and 23.9% of the patients with various other spinal conditions. The initial EFA provided a hypothetical construct for consideration. Subsequent CFA was considered in three scenarios: the full sample and separate genders. Models were compared empirically for best fit. The EFA indicated a one-factor solution accounting for 54% of the total variance. The CFA analysis based on the full sample confirmed this one-factor structure. Sub-group analyses by gender achieved good model fit for configural and partial metric invariance, but not scalar invariance. A possible two-construct model solution as outlined by previous researchers: dynamic-activities (personal care, lifting, walking, sex and social) and static-activities (pain, sleep, standing, travelling and sitting) was not preferred. The ODI demonstrated a one-factor structure in a large LBP sample. A potential two-factor model was considered, but not found appropriate for constructs of dynamic and static activity. The use of the single summary score for the ODI is psychometrically supported. However, practicality limitations were reported for use in the clinical and research settings. Researchers are encouraged to consider a shift towards newer, more sensitive and robustly developed instruments.

A Confirmatory Factor Analysis of the Structure of Abbreviated Math Anxiety Scale

Directory of Open Access Journals (Sweden)

Farahman Farrokhi

2011-06-01

Full Text Available "nObjective: The aim of this study is to explore the confirmatory factor analysis results of the Persian adaptation of Abbreviated Math Anxiety Scale (AMAS, proposed by Hopko, Mahadevan, Bare & Hunt. "nMethod: The validity and reliability assessments of the scale were performed on 298 college students chosen randomly from Tabriz University in Iran. The confirmatory factor analysis (CFA was carried out to determine the factor structures of the Persian version of AMAS. "nResults: As expected, the two-factor solution provided a better fit to the data than a single factor. Moreover, multi-group analyses showed that this two-factor structure was invariant across sex. Hence, AMAS provides an equally valid measure for use among college students. "nConclusions:  Brief AMAS demonstrates adequate reliability and validity. The AMAS scores can be used to compare symptoms of math anxiety between male and female students. The study both expands and adds support to the existing body of math anxiety literature.

3D Product authenticity model for online retail: An invariance analysis

Directory of Open Access Journals (Sweden)

Algharabat, R.

2010-01-01

Full Text Available This study investigates the effects of different levels of invariance analysis on three dimensional (3D product authenticity model (3DPAM constructs in the e- retailing context. A hypothetical retailer website presents a variety of laptops using 3D product visualisations. The proposed conceptual model achieves acceptable fit and the hypothesised paths are all valid. We empirically investigate the invariance across the subgroups to validate the results of our 3DPAM. We concluded that the 3D product authenticity model construct was invariant for our sample across different gender, level of education and study backgrounds. These findings suggested that all our subgroups conceptualised the 3DPAM similarly. Also the results show some non-invariance results for the structural and latent mean models. The gender group posits a non-invariance latent mean model. Study backgrounds group reveals a non-invariance result for the structural model. These findings allowed us to understand the 3DPAMs validity in the e-retail context. Managerial implications are explained.

Testing Lorentz invariance of dark matter

CERN Document Server

Blas, Diego; Sibiryakov, Sergey

2012-01-01

We study the possibility to constrain deviations from Lorentz invariance in dark matter (DM) with cosmological observations. Breaking of Lorentz invariance generically introduces new light gravitational degrees of freedom, which we represent through a dynamical timelike vector field. If DM does not obey Lorentz invariance, it couples to this vector field. We find that this coupling affects the inertial mass of small DM halos which no longer satisfy the equivalence principle. For large enough lumps of DM we identify a (chameleon) mechanism that restores the inertial mass to its standard value. As a consequence, the dynamics of gravitational clustering are modified. Two prominent effects are a scale dependent enhancement in the growth of large scale structure and a scale dependent bias between DM and baryon density perturbations. The comparison with the measured linear matter power spectrum in principle allows to bound the departure from Lorentz invariance of DM at the per cent level.

Testing Lorentz invariance of dark matter

Energy Technology Data Exchange (ETDEWEB)

Blas, Diego [Theory Group, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Ivanov, Mikhail M.; Sibiryakov, Sergey, E-mail: diego.blas@cern.ch, E-mail: mm.ivanov@physics.msu.ru, E-mail: sibir@inr.ac.ru [Faculty of Physics, Moscow State University, Vorobjevy Gory, 119991 Moscow (Russian Federation)

2012-10-01

We study the possibility to constrain deviations from Lorentz invariance in dark matter (DM) with cosmological observations. Breaking of Lorentz invariance generically introduces new light gravitational degrees of freedom, which we represent through a dynamical timelike vector field. If DM does not obey Lorentz invariance, it couples to this vector field. We find that this coupling affects the inertial mass of small DM halos which no longer satisfy the equivalence principle. For large enough lumps of DM we identify a (chameleon) mechanism that restores the inertial mass to its standard value. As a consequence, the dynamics of gravitational clustering are modified. Two prominent effects are a scale dependent enhancement in the growth of large scale structure and a scale dependent bias between DM and baryon density perturbations. The comparison with the measured linear matter power spectrum in principle allows to bound the departure from Lorentz invariance of DM at the per cent level.

Inertial Spontaneous Symmetry Breaking and Quantum Scale Invariance

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Pedro G. [Oxford U.; Hill, Christopher T. [Fermilab; Ross, Graham G. [Oxford U., Theor. Phys.

2018-01-23

Weyl invariant theories of scalars and gravity can generate all mass scales spontaneously, initiated by a dynamical process of "inertial spontaneous symmetry breaking" that does not involve a potential. This is dictated by the structure of the Weyl current, $K_\\mu$, and a cosmological phase during which the universe expands and the Einstein-Hilbert effective action is formed. Maintaining exact Weyl invariance in the renormalised quantum theory is straightforward when renormalisation conditions are referred back to the VEV's of fields in the action of the theory, which implies a conserved Weyl current. We do not require scale invariant regulators. We illustrate the computation of a Weyl invariant Coleman-Weinberg potential.

Measurement Invariance and Latent Mean Differences in the Reynolds Intellectual Assessment Scales (RIAS): Does the German Version of the RIAS Allow a Valid Assessment of Individuals with a Migration Background?

Science.gov (United States)

Gygi, Jasmin T.; Fux, Elodie; Grob, Alexander; Hagmann-von Arx, Priska

2016-01-01

This study examined measurement invariance and latent mean differences in the German version of the Reynolds Intellectual Assessment Scales (RIAS) for 316 individuals with a migration background (defined as speaking German as a second language) and 316 sex- and age-matched natives. The RIAS measures general intelligence (single-factor structure) and its two components, verbal and nonverbal intelligence (two-factor structure). Results of a multi-group confirmatory factor analysis showed scalar invariance for the two-factor and partial scalar invariance for the single-factor structure. We conclude that the two-factor structure of the RIAS is comparable across groups. Hence, verbal and nonverbal intelligence but not general intelligence should be considered when comparing RIAS test results of individuals with and without a migration background. Further, latent mean differences especially on the verbal, but also on the nonverbal intelligence index indicate language barriers for individuals with a migration background, as subtests corresponding to verbal intelligence require higher skills in German language. Moreover, cultural, environmental, and social factors that have to be taken into account when assessing individuals with a migration background are discussed. PMID:27846270

Measurement Invariance and Latent Mean Differences in the Reynolds Intellectual Assessment Scales (RIAS: Does the German Version of the RIAS Allow a Valid Assessment of Individuals with a Migration Background?

Directory of Open Access Journals (Sweden)

Jasmin T Gygi

Full Text Available This study examined measurement invariance and latent mean differences in the German version of the Reynolds Intellectual Assessment Scales (RIAS for 316 individuals with a migration background (defined as speaking German as a second language and 316 sex- and age-matched natives. The RIAS measures general intelligence (single-factor structure and its two components, verbal and nonverbal intelligence (two-factor structure. Results of a multi-group confirmatory factor analysis showed scalar invariance for the two-factor and partial scalar invariance for the single-factor structure. We conclude that the two-factor structure of the RIAS is comparable across groups. Hence, verbal and nonverbal intelligence but not general intelligence should be considered when comparing RIAS test results of individuals with and without a migration background. Further, latent mean differences especially on the verbal, but also on the nonverbal intelligence index indicate language barriers for individuals with a migration background, as subtests corresponding to verbal intelligence require higher skills in German language. Moreover, cultural, environmental, and social factors that have to be taken into account when assessing individuals with a migration background are discussed.

Cross-cultural examination of measurement invariance of the Beck Depression Inventory-II.

Science.gov (United States)

Dere, Jessica; Watters, Carolyn A; Yu, Stephanie Chee-Min; Bagby, R Michael; Ryder, Andrew G; Harkness, Kate L

2015-03-01

Given substantial rates of major depressive disorder among college and university students, as well as the growing cultural diversity on many campuses, establishing the cross-cultural validity of relevant assessment tools is important. In the current investigation, we examined the Beck Depression Inventory-Second Edition (BDI-II; Beck, Steer, & Brown, 1996) among Chinese-heritage (n = 933) and European-heritage (n = 933) undergraduates in North America. The investigation integrated 3 distinct lines of inquiry: (a) the literature on cultural variation in depressive symptom reporting between people of Chinese and Western heritage; (b) recent developments regarding the factor structure of the BDI-II; and (c) the application of advanced statistical techniques to the issue of cross-cultural measurement invariance. A bifactor model was found to represent the optimal factor structure of the BDI-II. Multigroup confirmatory factor analysis showed that the BDI-II had strong measurement invariance across both culture and gender. In group comparisons with latent and observed variables, Chinese-heritage students scored higher than European-heritage students on cognitive symptoms of depression. This finding deviates from the commonly held view that those of Chinese heritage somatize depression. These findings hold implications for the study and use of the BDI-II, highlight the value of advanced statistical techniques such as multigroup confirmatory factor analysis, and offer methodological lessons for cross-cultural psychopathology research more broadly. 2015 APA, all rights reserved

The Youth Psychopathic Traits Inventory: A Bifactor Model, Dimensionality, and Measurement Invariance.

Science.gov (United States)

Zwaanswijk, Wendy; Veen, Violaine C; Vedder, Paul

2017-10-01

The current study examines a bifactor model for the Youth Psychopathic Traits Inventory (YPI) in a Dutch community sample of adolescents ( N = 2,874). The primary goal was to examine the latent structure of the YPI with a bifactor modeling approach. Furthermore, the study examines the dimensionality and measurement invariance of the YPI. Results show that a bifactor model at subscale level fits the YPI best. The general psychopathy factor influences the 10 subscales of the YPI strongly, indicating that the YPI seems to be rather unidimensional than multidimensional. Nevertheless, the dimensions still explain nearly one third of the variance found. Findings imply that the bifactor model of the YPI should be used when examining relations with outcome variables, with a focus on the total score of the YPI, while factor scores should be reported with caution. Furthermore, the bifactor model appears invariant for gender, age, and ethnic background.

Análisis estructural e invarianza de medición del MBI-GS en trabajadores peruanos (Structural Analysis and Measurement Invariance of MBI-GS in Peruvian Workers

Directory of Open Access Journals (Sweden)

Manuel Fernández-Arata

2015-06-01

Full Text Available Resumen La medición del burnout ha evolucionado con la creación de varios instrumentos y modelos. El Maslach Burnout Inventory - General Survey (MBI-GS es uno de estos instrumentos para medir tres constructos definicionales del burnout: (1 agotamiento emocional, (2 eficacia profesional y (3 indiferencia. Fue creado para un amplio rango de ocupaciones, pero pocas veces se ha verificado su estructura latente e invarianza de medición en Latinoamérica. El presente estudio analiza esta estructura latente y la invarianza de medición del MBI-GS en una muestra de 940 trabajadores peruanos de varias ocupaciones. Se aplicó la metodología de ecuaciones estructurales mediante el análisis factorial confirmatorio, así como la invarianza de medición entre varones y mujeres, imponiendo restricciones sucesivamente más estrictas. Los resultados verificaron satisfactoriamente la estructura de tres dimensiones latentes del MBI-GS, y la invarianza de sus parámetros entre hombres y mujeres. Se discute las implicaciones de los resultados. Abstract The measurement of burnout has evolved into the creation of various tools and models. The Maslach Burnout Inventory - General Survey (MBI-GS is one of these instruments used to measure three definitional constructs of burnout: (1 emotional exhaustion, (2 professional efficiency, and (3 indifference. It was created for a wide range of occupations, but its latent structure and invariance of measurement in Latin America has rarely been verified. The present study analyzes the latent structure and the invariance of measurement of MBI-GS in a sample of 940 Peruvian workers in various occupations. The methodology of structural equations was applied through the confirmatory factor analysis, as well as the invariance of measurement between men and women, imposing restrictions successively more strict. The results satisfactorily verified the structure of three-dimensional latent MBI-GS, and the invariance of its

The Schizotypal Personality Questionnaire-Brief lacks measurement invariance across three countries.

Science.gov (United States)

Liu, Shujuan; Mellor, David; Ling, Mathew; Saiz, José L; Vinet, Eugenia V; Xu, Xiaoyan; Renati, Solomon; Byrne, Linda K

2017-12-01

The Schizotypal Personality Questionnaire-Brief (SPQ-B) is a commonly-used tool for measuring schizotypal personality traits and due to its wide application, its cross-cultural validity is of interest. Previous studies suggest that the SPQ-B either has a three- or four-factor structure, but the majority of studies have been conducted in Western contexts and little is known about the psychometric properties of the scale in other populations. In this study factorial invariance testing across three cultural contexts-Australia, China and Chile was conducted. In total, 729 young adults (Mean age = 23.99 years, SD = 9.87 years) participated. Invariance testing did not support the four-factor model across three countries. Confirmatory Factor Analyses revealed that neither the four- nor three-factor model had strong fit in any of the settings. However, in comparison with other competing models, the four-factor model showed the best for the Australian sample, while the three-factor model was the most reasonable for both Chinese and Chilean samples. The reliability of the SPQ-B scores, estimated with Omega, ranged from 0.86 to 0.91. These findings suggest that the SPQ-B factors are not consistent across different cultural groups. We suggest that these differences could be attributed to potential confounding cultural and translation issues. Copyright © 2017 Elsevier B.V. All rights reserved.

Invariant submanifold flows

Energy Technology Data Exchange (ETDEWEB)

Olver, Peter J [School of Mathematics, University of Minnesota, Minneapolis, MN 55455 (United States)], E-mail: olver@math.umn.edu

2008-08-29

Given a Lie group acting on a manifold, our aim is to analyze the evolution of differential invariants under invariant submanifold flows. The constructions are based on the equivariant method of moving frames and the induced invariant variational bicomplex. Applications to integrable soliton dynamics, and to the evolution of differential invariant signatures, used in equivalence problems and object recognition and symmetry detection in images, are discussed.

Implicit Moment Invariants

Czech Academy of Sciences Publication Activity Database

Flusser, Jan; Kautský, J.; Šroubek, Filip

2010-01-01

Roč. 86, č. 1 (2010), s. 72-86 ISSN 0920-5691 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/1593 Institutional research plan: CEZ:AV0Z10750506 Keywords : Implicit invariants * Orthogonal polynomials * Polynomial image deformation Subject RIV: BD - Theory of Information Impact factor: 4.930, year: 2010 http://library.utia.cas.cz/separaty/2009/ZOI/flusser-0329394.pdf

3D rotation invariants of Gaussian-Hermite moments

Czech Academy of Sciences Publication Activity Database

Yang, Bo; Flusser, Jan; Suk, Tomáš

2015-01-01

Roč. 54, č. 1 (2015), s. 18-26 ISSN 0167-8655 R&D Projects: GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Rotation invariants * Orthogonal moments * Gaussian–Hermite moments * 3D moment invariants Subject RIV: IN - Informatics, Computer Science Impact factor: 1.586, year: 2015 http://library.utia.cas.cz/separaty/2014/ZOI/yang-0438325.pdf

Factorial invariance of the Satisfaction with Life Scale in adolescents from Spain and Portugal.

Science.gov (United States)

Atienza González, Francisco L; Balaguer Solá, Isabel; Corte-Real, Nuno; Fonseca, António M

2016-08-01

The Satisfaction with Life Scale is one of the most widely used scales to measure the global cognitive judgment of satisfaction with one’s life. This study assesses the equivalence of the SWLS across Spanish and Portuguese adolescents, using multi-sample Confirmatory Factor Analysis. Participants were Spanish (N = 2183) and Portuguese (N = 4082) junior high school. The results provide high support for the internal consistency of both the Spanish and Portuguese versions of this scale. The results also showed that factor structure, factor loadings, could be considered invariant across groups. However, the full scalar invariance between Spanish and Portuguese samples was not found, with the intercept for SWLS item 5 varying across countries. Similar findings have also been found in other cross-national studies with this scale. Implications of the findings are discussed and we conclude that the Spanish and Portuguese versions of the SWLS can be used for cross-national comparisons with Spanish and Portuguese adolescents.

Factorial Validity and Invariance Assessment of a Short Version of the Recalled Childhood Gender Identity/Role Questionnaire.

Science.gov (United States)

Veale, Jaimie F

2016-04-01

Recalled childhood gender role/identity is a construct that is related to sexual orientation, abuse, and psychological health. The purpose of this study was to assess the factorial validity of a short version of Zucker et al.'s (2006) "Recalled Childhood Gender Identity/Gender Role Questionnaire" using confirmatory factor analysis and to test the stability of the factor structure across groups (measurement invariance). Six items of the questionnaire were completed online by 1929 participants from a variety of gender identity and sexual orientation groups. Models of the six items loading onto one factor had poor fit for the data. Items were removed for having a large proportion of error variance. Among birth-assigned females, a five-item model had good fit for the data, but there was evidence for differences in scale's factor structure across gender identity, age, level of education, and country groups. Among birth-assigned males, the resulting four-item model did not account for all of the relationship between variables, and modeling for this resulted in a model that was almost saturated. This model also had evidence of measurement variance across gender identity and sexual orientation groups. The models had good reliability and factor score determinacy. These findings suggest that results of previous studies that have assessed recalled childhood gender role/identity may have been susceptible to construct bias due to measurement variance across these groups. Future studies should assess measurement invariance between groups they are comparing, and if it is not found the issue can be addressed by removing variant indicators and/or applying a partial invariance model.

Invariant renormalization method for nonlinear realizations of dynamical symmetries

International Nuclear Information System (INIS)

Kazakov, D.I.; Pervushin, V.N.; Pushkin, S.V.

1977-01-01

The structure of ultraviolet divergences is investigated for the field theoretical models with nonlinear realization of the arbitrary semisimple Lie group, with spontaneously broken symmetry of vacuum. An invariant formulation of the background field method of renormalization is proposed which gives the manifest invariant counterterms off mass shell. A simple algorithm for construction of counterterms is developed. It is based on invariants of the group of dynamical symmetry in terms of the Cartan forms. The results of one-loop and two-loop calculations are reported

On the hierarchy of partially invariant submodels of differential equations

Energy Technology Data Exchange (ETDEWEB)

Golovin, Sergey V [Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk 630090 (Russian Federation)], E-mail: sergey@hydro.nsc.ru

2008-07-04

It is noted that the partially invariant solution (PIS) of differential equations in many cases can be represented as an invariant reduction of some PISs of the higher rank. This introduces a hierarchic structure in the set of all PISs of a given system of differential equations. An equivalence of the two-step and the direct ways of construction of PISs is proved. The hierarchy simplifies the process of enumeration and analysis of partially invariant submodels to the given system of differential equations. In this framework, the complete classification of regular partially invariant solutions of ideal MHD equations is given.

On the hierarchy of partially invariant submodels of differential equations

Science.gov (United States)

Golovin, Sergey V.

2008-07-01

It is noted that the partially invariant solution (PIS) of differential equations in many cases can be represented as an invariant reduction of some PISs of the higher rank. This introduces a hierarchic structure in the set of all PISs of a given system of differential equations. An equivalence of the two-step and the direct ways of construction of PISs is proved. The hierarchy simplifies the process of enumeration and analysis of partially invariant submodels to the given system of differential equations. In this framework, the complete classification of regular partially invariant solutions of ideal MHD equations is given.

On the hierarchy of partially invariant submodels of differential equations

International Nuclear Information System (INIS)

Golovin, Sergey V

2008-01-01

It is noted that the partially invariant solution (PIS) of differential equations in many cases can be represented as an invariant reduction of some PISs of the higher rank. This introduces a hierarchic structure in the set of all PISs of a given system of differential equations. An equivalence of the two-step and the direct ways of construction of PISs is proved. The hierarchy simplifies the process of enumeration and analysis of partially invariant submodels to the given system of differential equations. In this framework, the complete classification of regular partially invariant solutions of ideal MHD equations is given

Size invariance of the granular Rayleigh-Taylor instability.

Science.gov (United States)

Vinningland, Jan Ludvig; Johnsen, Øistein; Flekkøy, Eirik G; Toussaint, Renaud; Måløy, Knut Jørgen

2010-04-01

The size scaling behavior of the granular Rayleigh-Taylor instability [J. L. Vinningland, Phys. Rev. Lett. 99, 048001 (2007)] is investigated experimentally, numerically, and theoretically. An upper layer of grains displaces a lower gap of air by organizing into dense fingers of falling grains separated by rising bubbles of air. The dependence of these structures on the system and grain sizes is investigated. A spatial measurement of the finger structures is obtained by the Fourier power spectrum of the wave number k. As the size of the grains increases the wave number decreases accordingly which leaves the dimensionless product of wave number and grain diameter, dk, invariant. A theoretical interpretation of the invariance, based on the scaling properties of the model equations, suggests a gradual breakdown of the invariance for grains smaller than approximately 70 microm or greater than approximately 570 microm in diameter.

Gender differences in the factor structure of posttraumatic stress disorder symptoms in war-exposed adolescents.

Science.gov (United States)

Armour, Cherie; Elhai, Jon D; Layne, Christopher M; Shevlin, Mark; Duraković-Belko, Elvira; Djapo, Nermin; Pynoos, Robert S

2011-05-01

DSM-IV's three-factor model of posttraumatic stress disorder (PTSD) is rarely empirically supported, whereas other four-factor models (King et al., 1998; Simms, Watson, & Doebbeling, 2002) have proven to be better representations of PTSD's latent structure. To date, a clear consensus as to which model provides the best representation of PTSD's underlying dimensions has yet to be reached. The current study investigated whether gender is associated with factor structure differences using the King et al. (1998) model of reexperiencing, avoidance, numbing, and hyperarousal PTSD symptoms. Participants were war-exposed Bosnian secondary/high school boys and girls (N=1572) assessed nearly two years after the 1992-1995 Bosnian conflict. Confirmatory factor analytic tests of measurement invariance across PTSD model parameters revealed many significant sex-linked differences. Implications regarding the potential role of gender as a moderator of the King et al. (1998) model's factor structure are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Modular invariants and fusion rule automorphisms from Galois theory

International Nuclear Information System (INIS)

Fuchs, J.; Gato-Rivera, B.; Schellekens, B.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica; Schweigert, C.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

1994-05-01

We show that Galois theory of cyclotomic number fields provides a powerful tool to construct systematically integer-valued matrices commuting with the modular matrix S, as well as automorphisms of the fusion rules. Both of these prescriptions allow the construction of modular invariants and offer new insight in the structure of known exceptional invariants. (orig.)

Measurement Invariance of the "Servant Leadership Questionnaire" across K-12 Principal Gender

Science.gov (United States)

Xu, Lihua; Stewart, Trae; Haber-Curran, Paige

2015-01-01

Measurement invariance of the five-factor "Servant Leadership Questionnaire" between female and male K-12 principals was tested using multi-group confirmatory factor analysis. A sample of 956 principals (56.9% were females and 43.1% were males) was analysed in this study. The hierarchical multi-step measurement invariance test supported…

The Loneliness Questionnaire: Establishing Measurement Invariance Across Ethnic Groups.

Science.gov (United States)

Ritchwood, Tiarney D; Ebesutani, Chad K; Chin, Eu Gene; Young, John

2017-09-01

A state of loneliness describes an individual's perception of having dissatisfying social connections to others. Though it is notable across the life span, it may have particularly deleterious effects in childhood and adolescence, leading to increased risk of emotional impairment. The current study evaluates a widely used test of loneliness, the Loneliness Questionnaire, for measurement invariance across ethnic groups in a large, representative sample of youth in the 2nd to 12th grades ( N = 12,344; 41% African American) in Mississippi. Analyses were conducted using multigroup confirmatory factor analysis following a published, sequential method to examine invariance in form, factor loadings, and item intercepts. Overall, our results indicated that the instrument was invariant across ethnicities, suggesting that youth with equivalent manifest scores can be discerned as having comparable levels of latent loneliness. The loneliness scores also corresponded significantly with depression and anxiety scores for most subsamples, with one exception. These findings are discussed in the context of previous results comparing levels of loneliness across ethnicities. Additionally, the broader context of the need to expand invariance studies in instrumentation work is highlighted.

Assessing the factor structure of posttraumatic stress disorder symptoms in war-exposed youths with and without Criterion A2 endorsement.

Science.gov (United States)

Armour, Cherie; Layne, Christopher M; Naifeh, James A; Shevlin, Mark; Duraković-Belko, Elvira; Djapo, Nermin; Pynoos, Robert S; Elhai, Jon D

2011-01-01

Posttraumatic stress disorder's (PTSD) tripartite factor structure proposed by the DSM-IV is rarely empirically supported. Other four-factor models (King et al., 1998; Simms et al., 2002) have proven to better account for PTSD's latent structure; however, results regarding model superiority are conflicting. The current study assessed whether endorsement of PTSD's Criterion A2 would impact on the factorial invariance of the King et al. (1998) model. Participants were 1572 war-exposed Bosnian secondary students who were assessed two years following the 1992-1995 Bosnian conflict. The sample was grouped by those endorsing both parts of the DSM-IV Criterion A (A2 Group) and those endorsing only A1 (Non-A2 Group). The factorial invariance of the King et al. (1998) model was not supported between the A2 vs. Non-A2 Groups; rather, the groups significantly differed on all model parameters. The impact of removing A2 on the factor structure of King et al. (1998) PTSD model is discussed in light of the proposed removal of Criterion A2 for the DSM-V. Copyright © 2010 Elsevier Ltd. All rights reserved.

A Test for Cluster Bias: Detecting Violations of Measurement Invariance across Clusters in Multilevel Data

Science.gov (United States)

Jak, Suzanne; Oort, Frans J.; Dolan, Conor V.

2013-01-01

We present a test for cluster bias, which can be used to detect violations of measurement invariance across clusters in 2-level data. We show how measurement invariance assumptions across clusters imply measurement invariance across levels in a 2-level factor model. Cluster bias is investigated by testing whether the within-level factor loadings…

Personality in general and clinical samples: Measurement invariance of the Multidimensional Personality Questionnaire.

Science.gov (United States)

Eigenhuis, Annemarie; Kamphuis, Jan H; Noordhof, Arjen

2017-09-01

A growing body of research suggests that the same general dimensions can describe normal and pathological personality, but most of the supporting evidence is exploratory. We aim to determine in a confirmatory framework the extent to which responses on the Multidimensional Personality Questionnaire (MPQ) are identical across general and clinical samples. We tested the Dutch brief form of the MPQ (MPQ-BF-NL) for measurement invariance across a general population subsample (N = 365) and a clinical sample (N = 365), using Multiple Group Confirmatory Factor Analysis (MGCFA) and Multiple Group Exploratory Structural Equation Modeling (MGESEM). As an omnibus personality test, the MPQ-BF-NL revealed strict invariance, indicating absence of bias. Unidimensional per scale tests for measurement invariance revealed that 10% of items appeared to contain bias across samples. Item bias only affected the scale interpretation of Achievement, with individuals from the clinical sample more readily admitting to put high demands on themselves than individuals from the general sample, regardless of trait level. This formal test of equivalence provides strong evidence for the common structure of normal and pathological personality and lends further support to the clinical utility of the MPQ. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Examination of the factor structure of the Schizotypal Personality Questionnaire among British and Trinidadian adults.

Science.gov (United States)

Barron, David; Swami, Viren; Towell, Tony; Hutchinson, Gerard; Morgan, Kevin D

2015-01-01

Much debate in schizotypal research has centred on the factor structure of the Schizotypal Personality Questionnaire (SPQ), with research variously showing higher-order dimensionality consisting of two to seven dimensions. In addition, cross-cultural support for the stability of those factors remains limited. Here, we examined the factor structure of the SPQ among British and Trinidadian adults. Participants from a White British subsample (n = 351) resident in the UK and from an African Caribbean subsample (n = 284) resident in Trinidad completed the SPQ. The higher-order factor structure of the SPQ was analysed through confirmatory factor analysis, followed by multiple-group analysis for the model of best fit. Between-group differences for sex and ethnicity were investigated using multivariate analysis of variance in relation to the higher-order domains. The model of best-fit was the four-factor structure, which demonstrated measurement invariance across groups. Additionally, these data had an adequate fit for two alternative models: (a) 3-factor and (b) modified 4-factor model. The British subsample had significantly higher scores across all domains than the Trinidadian group, and men scored significantly higher on the disorganised domain than women. The four-factor structure received confirmatory support and, importantly, support for use with populations varying in ethnicity and culture.

Testing the Invariance of the National Health and Nutrition Examination Survey's Sexual Behavior Questionnaire Across Gender, Ethnicity/Race, and Generation.

Science.gov (United States)

Zhou, Anne Q; Hsueh, Loretta; Roesch, Scott C; Vaughn, Allison A; Sotelo, Frank L; Lindsay, Suzanne; Klonoff, Elizabeth A

2016-02-01

Federal and state policies are based on data from surveys that examine sexual-related cognitions and behaviors through self-reports of attitudes and actions. No study has yet examined their factorial invariance--specifically, whether the relationship between items assessing sexual behavior and their underlying construct differ depending on gender, ethnicity/race, or age. This study examined the factor structure of four items from the sexual behavior questionnaire part of the National Health and Nutrition Examination Survey (NHANES). As NHANES provided different versions of the survey per gender, invariance was tested across gender to determine whether subsequent tests across ethnicity/race and generation could be done across gender. Items were not invariant across gender groups so data files for women and men were not collapsed. Across ethnicity/race for both genders, and across generation for women, items were configurally invariant, and exhibited metric invariance across Latino/Latina and Black participants for both genders. Across generation for men, the configural invariance model could not be identified so the baseline models were examined. The four item one factor model fit well for the Millennial and GenerationX groups but was a poor fit for the baby boomer and silent generation groups, suggesting that gender moderated the invariance across generation. Thus, comparisons between ethnic/racial and generational groups should not be made between the genders or even within gender. Findings highlight the need for programs and interventions that promote a more inclusive definition of "having had sex."

The Youth Psychopathic Traits Inventory: Measurement Invariance and Psychometric Properties among Portuguese Youths

Directory of Open Access Journals (Sweden)

Pedro Pechorro

2016-08-01

Full Text Available The aim of the present study was to examine the psychometric properties of the Youth Psychopathic Traits Inventory (YPI among a mixed-gender sample of 782 Portuguese youth (M = 15.87 years; SD = 1.72, in a school context. Confirmatory factor analysis revealed the expected three-factor first-order structure. Cross-gender measurement invariance and cross-sample measurement invariance using a forensic sample of institutionalized males were also confirmed. The Portuguese version of the YPI demonstrated generally adequate psychometric properties of internal consistency, mean inter-item correlation, convergent validity, discriminant validity, and criterion-related validity of statistically significant associations with conduct disorder symptoms, alcohol abuse, drug use, and unprotected sex. In terms of known-groups validity, males scored higher than females, and males from the school sample scored lower than institutionalized males. The use of the YPI among the Portuguese male and female youth population is psychometrically justified, and it can be a useful measure to identify adolescents with high levels of psychopathic traits.

Invariant and Absolute Invariant Means of Double Sequences

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Abdullah Alotaibi

2012-01-01

Full Text Available We examine some properties of the invariant mean, define the concepts of strong σ-convergence and absolute σ-convergence for double sequences, and determine the associated sublinear functionals. We also define the absolute invariant mean through which the space of absolutely σ-convergent double sequences is characterized.

Rotation invariants from Gaussian-Hermite moments of color images

Czech Academy of Sciences Publication Activity Database

Yang, B.; Suk, Tomáš; Flusser, Jan; Shi, Z.; Chen, X.

2018-01-01

Roč. 143, č. 1 (2018), s. 282-291 ISSN 0165-1684 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Color images * Object recognition * Rotation invariants * Gaussian–Hermite moments * Joint invariants Subject RIV: JD - Computer Applications, Robotics Impact factor: 3.110, year: 2016 http://library.utia.cas.cz/separaty/2017/ZOI/suk-0479748.pdf

Second-order statistics of colour codes modulate transformations that effectuate varying degrees of scene invariance and illumination invariance.

Science.gov (United States)

Mausfeld, Rainer; Andres, Johannes

2002-01-01

We argue, from an ethology-inspired perspective, that the internal concepts 'surface colours' and 'illumination colours' are part of the data format of two different representational primitives. Thus, the internal concept of 'colour' is not a unitary one but rather refers to two different types of 'data structure', each with its own proprietary types of parameters and relations. The relation of these representational structures is modulated by a class of parameterised transformations whose effects are mirrored in the idealised computational achievements of illumination invariance of colour codes, on the one hand, and scene invariance, on the other hand. Because the same characteristics of a light array reaching the eye can be physically produced in many different ways, the visual system, then, has to make an 'inference' whether a chromatic deviation of the space-averaged colour codes from the neutral point is due to a 'non-normal', ie chromatic, illumination or due to an imbalanced spectral reflectance composition. We provide evidence that the visual system uses second-order statistics of chromatic codes of a single view of a scene in order to modulate corresponding transformations. In our experiments we used centre surround configurations with inhomogeneous surrounds given by a random structure of overlapping circles, referred to as Seurat configurations. Each family of surrounds has a fixed space-average of colour codes, but differs with respect to the covariance matrix of colour codes of pixels that defines the chromatic variance along some chromatic axis and the covariance between luminance and chromatic channels. We found that dominant wavelengths of red-green equilibrium settings of the infield exhibited a stable and strong dependence on the chromatic variance of the surround. High variances resulted in a tendency towards 'scene invariance', low variances in a tendency towards 'illumination invariance' of the infield.

Projection Operators and Moment Invariants to Image Blurring

Czech Academy of Sciences Publication Activity Database

Flusser, Jan; Suk, Tomáš; Boldyš, Jiří; Zitová, Barbara

2015-01-01

Roč. 37, č. 4 (2015), s. 786-802 ISSN 0162-8828 R&D Projects: GA ČR GA13-29225S; GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Blurred image * N-fold rotation symmetry * projection operators * image moments * moment invariants * blur invariants * object recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 6.077, year: 2015 http://library.utia.cas.cz/separaty/2014/ZOI/flusser-0434521.pdf

On the properties of quartet and quintet invariants and triplet seminvariants and their application in direct methods for X-ray structure determination

International Nuclear Information System (INIS)

Putten, N. van der.

1980-01-01

Expressions for the estimation of five-phase structure invariants and enantiomorph-sensitive three-phase (semin)variants and their applications in enantiomorph specific phase determination are presented. (Auth.)

Brazil-Portugal Transcultural Adaptation of the UWES-9: Internal Consistency, Dimensionality, and Measurement Invariance.

Science.gov (United States)

Sinval, Jorge; Pasian, Sonia; Queirós, Cristina; Marôco, João

2018-01-01

The aim of this paper is to present a revision of international versions of the Utrecht Work Engagement Scale and to describe the psychometric properties of a Portuguese version of the UWES-9 developed simultaneously for Brazil and Portugal, the validity evidence related with the internal structure, namely, Dimensionality, measurement invariance between Brazil and Portugal, and Reliability of the scores. This is the first UWES version developed simultaneously for both countries, and it is an important instrument for understanding employees' work engagement in the organizations, allowing human resources departments to better use workforces, especially when they are migrants. A total of 524 Brazilian workers and 522 Portuguese workers participated in the study. Confirmatory Factor Analysis, group comparisons, and Reliability estimates were used. The use of workers who were primarily professionals or administrative support, according to ISCO-08, reinforced the need to collect data on other professional occupations. Confirmatory factor analysis showed acceptable fit for the UWES-9 original three-factor solution, and a second-order factor structure has been proposed that presented an acceptable fit. Full-scale invariance was obtained between the Portuguese and Brazilian samples, both for the original three-factor first-order and second-order models. Data revealed that Portuguese and Brazilian workers didn't show statistically significant differences in the work engagement dimensions. This version allows for direct comparisons of means and, consequently, for performance of comparative and cross-cultural studies between these two countries.

Brazil-Portugal Transcultural Adaptation of the UWES-9: Internal Consistency, Dimensionality, and Measurement Invariance

Directory of Open Access Journals (Sweden)

Jorge Sinval

2018-03-01

Full Text Available The aim of this paper is to present a revision of international versions of the Utrecht Work Engagement Scale and to describe the psychometric properties of a Portuguese version of the UWES-9 developed simultaneously for Brazil and Portugal, the validity evidence related with the internal structure, namely, Dimensionality, measurement invariance between Brazil and Portugal, and Reliability of the scores. This is the first UWES version developed simultaneously for both countries, and it is an important instrument for understanding employees' work engagement in the organizations, allowing human resources departments to better use workforces, especially when they are migrants. A total of 524 Brazilian workers and 522 Portuguese workers participated in the study. Confirmatory Factor Analysis, group comparisons, and Reliability estimates were used. The use of workers who were primarily professionals or administrative support, according to ISCO-08, reinforced the need to collect data on other professional occupations. Confirmatory factor analysis showed acceptable fit for the UWES-9 original three-factor solution, and a second-order factor structure has been proposed that presented an acceptable fit. Full-scale invariance was obtained between the Portuguese and Brazilian samples, both for the original three-factor first-order and second-order models. Data revealed that Portuguese and Brazilian workers didn't show statistically significant differences in the work engagement dimensions. This version allows for direct comparisons of means and, consequently, for performance of comparative and cross-cultural studies between these two countries.

On the hierarchy of partially invariant submodels of differential equations

OpenAIRE

Golovin, Sergey V.

2007-01-01

It is noticed, that partially invariant solution (PIS) of differential equations in many cases can be represented as an invariant reduction of some PIS of the higher rank. This introduce a hierarchic structure in the set of all PISs of a given system of differential equations. By using this structure one can significantly decrease an amount of calculations required in enumeration of all PISs for a given system of partially differential equations. An equivalence of the two-step and the direct ...

Invariant and semi-invariant probabilistic normed spaces

Energy Technology Data Exchange (ETDEWEB)

Ghaemi, M.B. [School of Mathematics Iran, University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)], E-mail: mghaemi@iust.ac.ir; Lafuerza-Guillen, B. [Departamento de Estadistica y Matematica Aplicada, Universidad de Almeria, Almeria E-04120 (Spain)], E-mail: blafuerz@ual.es; Saiedinezhad, S. [School of Mathematics Iran, University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)], E-mail: ssaiedinezhad@yahoo.com

2009-10-15

Probabilistic metric spaces were introduced by Karl Menger. Alsina, Schweizer and Sklar gave a general definition of probabilistic normed space based on the definition of Menger . We introduce the concept of semi-invariance among the PN spaces. In this paper we will find a sufficient condition for some PN spaces to be semi-invariant. We will show that PN spaces are normal spaces. Urysohn's lemma, and Tietze extension theorem for them are proved.

Global self-esteem and method effects: competing factor structures, longitudinal invariance, and response styles in adolescents.

Science.gov (United States)

Urbán, Róbert; Szigeti, Réka; Kökönyei, Gyöngyi; Demetrovics, Zsolt

2014-06-01

The Rosenberg Self-Esteem Scale (RSES) is a widely used measure for assessing self-esteem, but its factor structure is debated. Our goals were to compare 10 alternative models for the RSES and to quantify and predict the method effects. This sample involves two waves (N =2,513 9th-grade and 2,370 10th-grade students) from five waves of a school-based longitudinal study. The RSES was administered in each wave. The global self-esteem factor with two latent method factors yielded the best fit to the data. The global factor explained a large amount of the common variance (61% and 46%); however, a relatively large proportion of the common variance was attributed to the negative method factor (34 % and 41%), and a small proportion of the common variance was explained by the positive method factor (5% and 13%). We conceptualized the method effect as a response style and found that being a girl and having a higher number of depressive symptoms were associated with both low self-esteem and negative response style, as measured by the negative method factor. Our study supported the one global self-esteem construct and quantified the method effects in adolescents.

Global self-esteem and method effects: competing factor structures, longitudinal invariance and response styles in adolescents

Science.gov (United States)

Urbán, Róbert; Szigeti, Réka; Kökönyei, Gyöngyi; Demetrovics, Zsolt

2013-01-01

The Rosenberg Self-Esteem Scale (RSES) is a widely used measure for assessing self-esteem, but its factor structure is debated. Our goals were to compare 10 alternative models for RSES; and to quantify and predict the method effects. This sample involves two waves (N=2513 ninth-grade and 2370 tenth-grade students) from five waves of a school-based longitudinal study. RSES was administered in each wave. The global self-esteem factor with two latent method factors yielded the best fit to the data. The global factor explained large amount of the common variance (61% and 46%); however, a relatively large proportion of the common variance was attributed to the negative method factor (34 % and 41%), and a small proportion of the common variance was explained by the positive method factor (5% and 13%). We conceptualized the method effect as a response style, and found that being a girl and having higher number of depressive symptoms were associated with both low self-esteem and negative response style measured by the negative method factor. Our study supported the one global self-esteem construct and quantified the method effects in adolescents. PMID:24061931

Time-varying and time-invariant dimensions of depression in children and adolescents: Implications for cross-informant agreement.

Science.gov (United States)

Cole, David A; Martin, Joan M; Jacquez, Farrah M; Tram, Jane M; Zelkowitz, Rachel; Nick, Elizabeth A; Rights, Jason D

2017-07-01

The longitudinal structure of depression in children and adolescents was examined by applying a Trait-State-Occasion structural equation model to 4 waves of self, teacher, peer, and parent reports in 2 age groups (9 to 13 and 13 to 16 years old). Analyses revealed that the depression latent variable consisted of 2 longitudinal factors: a time-invariant dimension that was completely stable over time and a time-varying dimension that was not perfectly stable over time. Different sources of information were differentially sensitive to these 2 dimensions. Among adolescents, self- and parent reports better reflected the time-invariant aspects. For children and adolescents, peer and teacher reports better reflected the time-varying aspects. Relatively high cross-informant agreement emerged for the time-invariant dimension in both children and adolescents. Cross-informant agreement for the time-varying dimension was high for adolescents but very low for children. Implications emerge for theoretical models of depression and for its measurement, especially when attempting to predict changes in depression in the context of longitudinal studies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

On local invariants of singular symplectic forms

Science.gov (United States)

Domitrz, Wojciech

2017-04-01

We find a complete set of local invariants of singular symplectic forms with the structurally stable Martinet hypersurface on a 2 n-dimensional manifold. In the C-analytic category this set consists of the Martinet hypersurface Σ2, the restriction of the singular symplectic form ω to TΣ2 and the kernel of ω n - 1 at the point p ∈Σ2. In the R-analytic and smooth categories this set contains one more invariant: the canonical orientation of Σ2. We find the conditions to determine the kernel of ω n - 1 at p by the other invariants. In dimension 4 we find sufficient conditions to determine the equivalence class of a singular symplectic form-germ with the structurally smooth Martinet hypersurface by the Martinet hypersurface and the restriction of the singular symplectic form to it. We also study the singular symplectic forms with singular Martinet hypersurfaces. We prove that the equivalence class of such singular symplectic form-germ is determined by the Martinet hypersurface, the canonical orientation of its regular part and the restriction of the singular symplectic form to its regular part if the Martinet hypersurface is a quasi-homogeneous hypersurface with an isolated singularity.

Galilei-invariant theory of low energy pion-nucleus scattering

International Nuclear Information System (INIS)

Mach, R.

1980-01-01

The scattering of a particle by a system of bound scatterers is investigated and reasons are given why the optical model and other models based on the standard impulse approximation violate the Galilei invariance. It is shown how this deficiency can be removed. Further, the validity of factojzation approximation is studied. In the case of Galilei-invariant models, there exists a unique combination of effective target particle momenta in the initial and final states, by means of which the optical potential can be expressed in factorized form (elementary scattering matrix by form factor of the composed target) while the error caused by the factorization procedure is of the order of projectile over target particle mass squared

Factor structure and gender stability in the multidimensional condom attitudes scale.

Science.gov (United States)

Starosta, Amy J; Berghoff, Christopher R; Earleywine, Mitch

2015-06-01

Sexually transmitted infections continue to trouble the United States and can be attenuated through increased condom use. Attitudes about condoms are an important multidimensional factor that can affect sexual health choices and have been successfully measured using the Multidimensional Condom Attitudes Scale (MCAS). Such attitudes have the potential to vary between men and women, yet little work has been undertaken to identify if the MCAS accurately captures attitudes without being influenced by underlying gender biases. We examined the factor structure and gender invariance on the MCAS using confirmatory factor analysis and item response theory, within-subscale differential item functioning analyses. More than 770 participants provided data via the Internet. Results of differential item functioning analyses identified three items as differentially functioning between the genders, and removal of these items is recommended. Findings confirmed the previously hypothesized multidimensional nature of condom attitudes and the five-factor structure of the MCAS even after the removal of the three problematic items. In general, comparisons across genders using the MCAS seem reasonable from a methodological standpoint. Results are discussed in terms of improving sexual health research and interventions. © The Author(s) 2014.

Assessing the factor structures of the 55- and 22-item versions of the conformity to masculine norms inventory.

Science.gov (United States)

Owen, Jesse

2011-03-01

The current study examined the psychometric properties of the abbreviated versions, 55- and 22-items, of the Conformity to Masculine Norms Inventory (CMNI). The authors tested the factor structure for the 11 subscales of the CMNI-55 and the global masculinity factor for the CMNI-55 and the CMNI-22. In a clinical sample of men and women (n=522), the results supported the 11-factor model. Furthermore, the factor structure was invariant for men and women. The higher order model, which tested the utility of the global masculine score, demonstrated marginal fit. The factor structures for the global masculinity score for the CMNI-22 demonstrated poor fit. Collectively, the results suggest that the CMNI-55 is better represented in a multidimensional construct. The subscales' alpha levels and factor loadings were, generally, within acceptable limits. Gender and ethnic mean level differences are also reported. © The Author(s) 2011

Testing measurement invariance of the schizotypal personality questionnaire-brief scores across Spanish and Swiss adolescents.

Directory of Open Access Journals (Sweden)

Javier Ortuño-Sierra

Full Text Available BACKGROUND: Schizotypy is a complex construct intimately related to psychosis. Empirical evidence indicates that participants with high scores on schizotypal self-report are at a heightened risk for the later development of psychotic disorders. Schizotypal experiences represent the behavioural expression of liability for psychotic disorders. Previous factorial studies have shown that schizotypy is a multidimensional construct similar to that found in patients with schizophrenia. Specifically, using the Schizotypal Personality Questionnaire-Brief (SPQ-B, the three-dimensional model has been widely replicated. However, there has been no in-depth investigation of whether the dimensional structure underlying the SPQ-B scores is invariant across countries. METHODS: The main goal of this study was to examine the measurement invariance of the SPQ-B scores across Spanish and Swiss adolescents. The final sample was made up of 261 Spanish participants (51.7% men; M = 16.04 years and 241 Swiss participants (52.3% men; M = 15.94 years. RESULTS: The results indicated that Raine et al.'s three-factor model presented adequate goodness-of-fit indices. Moreover, the results supported the measurement invariance (configural and partial strong invariance of the SPQ-B scores across the two samples. Spanish participants scored higher on Interpersonal dimension than Swiss when latent means were compared. DISCUSSION: The study of measurement equivalence across countries provides preliminary evidence for the Raine et al.'s three-factor model and of the cross-cultural validity of the SPQ-B scores in adolescent population. Future studies should continue to examine the measurement invariance of the schizotypy and psychosis-risk syndromes across cultures.

Rotationally invariant correlation filtering

International Nuclear Information System (INIS)

Schils, G.F.; Sweeney, D.W.

1985-01-01

A method is presented for analyzing and designing optical correlation filters that have tailored rotational invariance properties. The concept of a correlation of an image with a rotation of itself is introduced. A unified theory of rotation-invariant filtering is then formulated. The unified approach describes matched filters (with no rotation invariance) and circular-harmonic filters (with full rotation invariance) as special cases. The continuum of intermediate cases is described in terms of a cyclic convolution operation over angle. The angular filtering approach allows an exact choice for the continuous trade-off between loss of the correlation energy (or specificity regarding the image) and the amount of rotational invariance desired

Properties of invariant modelling and invariant glueing of vector fields

International Nuclear Information System (INIS)

Petukhov, V.R.

1987-01-01

Invariant modelling and invariant glueing of both continuous (rates and accelerations) and descrete vector fields, gradient and divergence cases are considered. The following appendices are discussed: vector fields in crystals, crystal disclinations, topological charges and their fields

Implicit leadership theories in applied settings: factor structure, generalizability, and stability over time.

Science.gov (United States)

Epitropaki, Olga; Martin, Robin

2004-04-01

The present empirical investigation had a 3-fold purpose: (a) to cross-validate L. R. Offermann, J. K. Kennedy, and P. W. Wirtz's (1994) scale of Implicit Leadership Theories (ILTs) in several organizational settings and to further provide a shorter scale of ILTs in organizations; (b) to assess the generalizability of ILTs across different employee groups, and (c) to evaluate ILTs' change over time. Two independent samples were used for the scale validation (N1 = 500 and N2 = 439). A 6-factor structure (Sensitivity, Intelligence, Dedication, Dynamism, Tyranny, and Masculinity) was found to most accurately represent ELTs in organizational settings. Regarding the generalizability of ILTs, although the 6-factor structure was consistent across different employee groups, there was only partial support for total factorial invariance. Finally, evaluation of gamma, beta, and alpha change provided support for ILTs' stability over time.

On the construction of translationally invariant deformed wave functions

International Nuclear Information System (INIS)

Guardiola, R.

1975-01-01

Translationally invariant nuclear wave functions are constructed from deformed harmonic oscillator shell-model wave functions, with an exact projection of angular momentum quantum numbers. It is shown that the computation of matrix elements with the translationally invariant wave functions is as simple as the standard calculation, and formulae are obtained for (i) the potential energy, (ii) the kinetic energy and rms radius, and (iii) the charge form factor. (Auth.)

Invariance of Parent Ratings of the ADHD Symptoms in Australian and Malaysian, and North European Australian and Malay Malaysia Children: A Mean and Covariance Structures Analysis Approach

Science.gov (United States)

Gomez, Rapson

2009-01-01

Objective: This study used the mean and covariance structures analysis approach to examine the equality or invariance of ratings of the 18 ADHD symptoms. Method: 783 Australian and 928 Malaysian parents provided ratings for an ADHD rating scale. Invariance was tested across these groups (Comparison 1), and North European Australian (n = 623) and…

QUIPS: Time-dependent properties of quasi-invariant self-gravitating polytropes

International Nuclear Information System (INIS)

Munier, A.; Feix, M.R.

1983-01-01

Quasi-invariance, a method based on group tranformations, is used to obtain time-dependent solutions for the expansion and/or contraction of a self-gravitating sphere of perfect gas with polytopic index n. Quasi-invariance transforms the equations of hydrodynamics into ''dual equations'' exhibiting extra terms such as a friction, a mass source or sink term, and a centripetal/centrifugal force. The search for stationary solutions in this ''dual space'' leads to a new class of time-dependent solutions, the QUIP (for Quasi-invariant polytrope), which generalizes Emden's static model and introduces a characteristic frequency a related to Jean's frequency. The second order differential equation describing the solution is integrated numerically. A critical point is seen always to exist for nnot =3. Solutions corresponding in the ''dual space'' to a time-dependent generalization of Eddington's standard model (n = 3) are discussed. These solutions conserve both the total mass and the energy. A transition between closed and open structures is seen to take place at a particular frequency a/sub c/. For n = 3, no critical point arises in the ''dual space'' due to the self-similar motion of the fluid. A new time-dependent mass-radius relation and a generalized Betti-Ritter relation are obtained. Conclusions about the existence of a minimum Q-factor are presented

Isomorph invariance of Couette shear flows simulated by the SLLOD equations of motion

DEFF Research Database (Denmark)

Separdar, Leila; Bailey, Nicholas; Schrøder, Thomas

2013-01-01

fluctuations of virial and potential energy. Such systems have good isomorphs (curves in the thermodynamic phase diagram along which structural, dynamical, and some thermodynamic quantities are invariant when expressed in reduced units). The SLLOD equations of motion were used to simulate Couette shear flows......Non-equilibrium molecular dynamics simulations were performed to study the thermodynamic, structural, and dynamical properties of the single-component Lennard-Jones and the Kob-Andersen binary Lennard-Jones liquids. Both systems are known to have strong correlations between equilibrium thermal...... of the two systems. We show analytically that these equations are isomorph invariant provided the reduced strain rate is fixed along the isomorph. Since isomorph invariance is generally only approximate, a range of strain rates were simulated to test for the predicted invariance, covering both the linear...

Q-phonons, Q-invariants, and company

International Nuclear Information System (INIS)

Brentano, P. von; Gade, A.; Pietralla, N.; Werner, V.

2002-01-01

The paper discusses the concept of Q-phonons and its connection to the concept of Q-invariants and the shape parameters of nuclei. It will also discuss some useful relations between Q-invariants and observables. These relations allow one to determine crucial nuclear observables such as the square of the quadrupole moment of the first 2+ state from lifetime data of the gamma- and ground band which may have applications, in future measurements with rare isotopes beams. These concepts are discussed for the Barium, Xenon and Cerium nuclei with mass numbers around A = 130, because some of these concepts were either introduced or at least heavily used in the discussion of the nuclear structure of these nuclei

Remarks on the E-invariant and the Casson invariant

International Nuclear Information System (INIS)

Seade, J.

1991-08-01

In this work a framed manifold means a pair (M,F) consisting of a closed C ∞ , stably parallelizable manifold M, together with a trivialization F of its stable tangent bundle. The purpose of this work is to understand and determine in higher dimensions the invariant h(M,F) appearing in connection with the Adams e-invariants. 28 refs

Factor Analysis for Finding Invariant Neural Descriptors of Human Emotions

Directory of Open Access Journals (Sweden)

Vitor Pereira

2018-01-01

Full Text Available A major challenge in decoding human emotions from electroencephalogram (EEG data is finding representations that are invariant to inter- and intrasubject differences. Most of the previous studies are focused in building an individual discrimination model for every subject (subject dependent model. Building subject-independent models is a harder problem due to the high data variability between different subjects and different experiments with the same subject. This paper explores, for the first time, the Factor Analysis as an efficient technique to extract temporal and spatial EEG features suitable to build brain-computer interface for decoding human emotions across various subjects. Our findings show that early waves (temporal window of 200–400 ms after the stimulus onset carry more information about the valence of the emotion. Also, spatial location of features, with a stronger impact on the emotional valence, occurs in the parietal and occipital regions of the brain. All discrimination models (NN, SVM, kNN, and RF demonstrate better discrimination rate of the positive valence. These results match closely experimental psychology hypothesis that, during early periods after the stimulus presentation, the brain response—to images with highly positive valence—is stronger.

Measurement invariance of the Portrait Values Questionnaire across 25 European countries

DEFF Research Database (Denmark)

Scholderer, Joachim

The Portrait Values Questionnaire (PVQ) is tested for cross-cultural validity. Measurement characteristics are compared across representative consumer samples from 25 European countries (total N = 37,592) using multi-group confirmatory factor analysis with structured means. The results suggest....... Hence, most direct comparisons of PVQ raw scores and sample statistics between European countries are valid without correction. Furthermore, it can be concluded that the ten values measured by the PVQ are invariant across European countries in terms of their relative position on the quasi......-circumplex hypothesised by the theory of basic human values....

Geometrical aspects of operator ordering terms in gauge invariant quantum models

International Nuclear Information System (INIS)

Houston, P.J.

1990-01-01

Finite-dimensional quantum models with both boson and fermion degrees of freedom, and which have a gauge invariance, are studied here as simple versions of gauge invariant quantum field theories. The configuration space of these finite-dimensional models has the structure of a principal fibre bundle and has defined on it a metric which is invariant under the action of the bundle or gauge group. When the gauge-dependent degrees of freedom are removed, thereby defining the quantum models on the base of the principal fibre bundle, extra operator ordering terms arise. By making use of dimensional reduction methods in removing the gauge dependence, expressions are obtained here for the operator ordering terms which show clearly their dependence on the geometry of the principal fibre bundle structure. (author)

On density of the Vassiliev invariants

DEFF Research Database (Denmark)

Røgen, Peter

1999-01-01

The main result is that the Vassiliev invariants are dense in the set of numeric knot invariants if and only if they separate knots.Keywords: Knots, Vassiliev invariants, separation, density, torus knots......The main result is that the Vassiliev invariants are dense in the set of numeric knot invariants if and only if they separate knots.Keywords: Knots, Vassiliev invariants, separation, density, torus knots...

Scale-invariant entropy-based theory for dynamic ordering

International Nuclear Information System (INIS)

Mahulikar, Shripad P.; Kumari, Priti

2014-01-01

Dynamically Ordered self-organized dissipative structure exists in various forms and at different scales. This investigation first introduces the concept of an isolated embedding system, which embeds an open system, e.g., dissipative structure and its mass and/or energy exchange with its surroundings. Thereafter, scale-invariant theoretical analysis is presented using thermodynamic principles for Order creation, existence, and destruction. The sustainability criterion for Order existence based on its structured mass and/or energy interactions with the surroundings is mathematically defined. This criterion forms the basis for the interrelationship of physical parameters during sustained existence of dynamic Order. It is shown that the sufficient condition for dynamic Order existence is approached if its sustainability criterion is met, i.e., its destruction path is blocked. This scale-invariant approach has the potential to unify the physical understanding of universal dynamic ordering based on entropy considerations

Multi-clues image retrieval based on improved color invariants

Science.gov (United States)

Liu, Liu; Li, Jian-Xun

2012-05-01

At present, image retrieval has a great progress in indexing efficiency and memory usage, which mainly benefits from the utilization of the text retrieval technology, such as the bag-of-features (BOF) model and the inverted-file structure. Meanwhile, because the robust local feature invariants are selected to establish BOF, the retrieval precision of BOF is enhanced, especially when it is applied to a large-scale database. However, these local feature invariants mainly consider the geometric variance of the objects in the images, and thus the color information of the objects fails to be made use of. Because of the development of the information technology and Internet, the majority of our retrieval objects is color images. Therefore, retrieval performance can be further improved through proper utilization of the color information. We propose an improved method through analyzing the flaw of shadow-shading quasi-invariant. The response and performance of shadow-shading quasi-invariant for the object edge with the variance of lighting are enhanced. The color descriptors of the invariant regions are extracted and integrated into BOF based on the local feature. The robustness of the algorithm and the improvement of the performance are verified in the final experiments.

Verification of Java Programs using Symbolic Execution and Invariant Generation

Science.gov (United States)

Pasareanu, Corina; Visser, Willem

2004-01-01

Software verification is recognized as an important and difficult problem. We present a norel framework, based on symbolic execution, for the automated verification of software. The framework uses annotations in the form of method specifications an3 loop invariants. We present a novel iterative technique that uses invariant strengthening and approximation for discovering these loop invariants automatically. The technique handles different types of data (e.g. boolean and numeric constraints, dynamically allocated structures and arrays) and it allows for checking universally quantified formulas. Our framework is built on top of the Java PathFinder model checking toolset and it was used for the verification of several non-trivial Java programs.

Cohomological invariants in Galois cohomology

CERN Document Server

Garibaldi, Skip; Serre, Jean Pierre

2003-01-01

This volume is concerned with algebraic invariants, such as the Stiefel-Whitney classes of quadratic forms (with values in Galois cohomology mod 2) and the trace form of �tale algebras (with values in the Witt ring). The invariants are analogues for Galois cohomology of the characteristic classes of topology. Historically, one of the first examples of cohomological invariants of the type considered here was the Hasse-Witt invariant of quadratic forms. The first part classifies such invariants in several cases. A principal tool is the notion of versal torsor, which is an analogue of the universal bundle in topology. The second part gives Rost's determination of the invariants of G-torsors with values in H^3(\\mathbb{Q}/\\mathbb{Z}(2)), when G is a semisimple, simply connected, linear group. This part gives detailed proofs of the existence and basic properties of the Rost invariant. This is the first time that most of this material appears in print.

Translationally invariant self-consistent field theories

International Nuclear Information System (INIS)

Shakin, C.M.; Weiss, M.S.

1977-01-01

We present a self-consistent field theory which is translationally invariant. The equations obtained go over to the usual Hartree-Fock equations in the limit of large particle number. In addition to deriving the dynamic equations for the self-consistent amplitudes we discuss the calculation of form factors and various other observables

Donaldson invariants in algebraic geometry

International Nuclear Information System (INIS)

Goettsche, L.

2000-01-01

In these lectures I want to give an introduction to the relation of Donaldson invariants with algebraic geometry: Donaldson invariants are differentiable invariants of smooth compact 4-manifolds X, defined via moduli spaces of anti-self-dual connections. If X is an algebraic surface, then these moduli spaces can for a suitable choice of the metric be identified with moduli spaces of stable vector bundles on X. This can be used to compute Donaldson invariants via methods of algebraic geometry and has led to a lot of activity on moduli spaces of vector bundles and coherent sheaves on algebraic surfaces. We will first recall the definition of the Donaldson invariants via gauge theory. Then we will show the relation between moduli spaces of anti-self-dual connections and moduli spaces of vector bundles on algebraic surfaces, and how this makes it possible to compute Donaldson invariants via algebraic geometry methods. Finally we concentrate on the case that the number b + of positive eigenvalues of the intersection form on the second homology of the 4-manifold is 1. In this case the Donaldson invariants depend on the metric (or in the algebraic geometric case on the polarization) via a system of walls and chambers. We will study the change of the invariants under wall-crossing, and use this in particular to compute the Donaldson invariants of rational algebraic surfaces. (author)

Moment invariants for particle beams

International Nuclear Information System (INIS)

Lysenko, W.P.; Overley, M.S.

1988-01-01

The rms emittance is a certain function of second moments in 2-D phase space. It is preserved for linear uncoupled (1-D) motion. In this paper, the authors present new functions of moments that are invariants for coupled motion. These invariants were computed symbolically using a computer algebra system. Possible applications for these invariants are discussed. Also, approximate moment invariants for nonlinear motion are presented

Conformal invariance and conserved quantities of Appell systems under second-class Mei symmetry

International Nuclear Information System (INIS)

Yi-Ping, Luo; Jing-Li, Fu

2010-01-01

In this paper we introduce the new concept of the conformal invariance and the conserved quantities for Appell systems under second-class Mei symmetry. The one-parameter infinitesimal transformation group and infinitesimal transformation vector of generator are described in detail. The conformal factor in the determining equations under second-class Mei symmetry is found. The relationship between Appell system's conformal invariance and Mei symmetry are discussed. And Appell system's conformal invariance under second-class Mei symmetry may lead to corresponding Hojman conserved quantities when the conformal invariance satisfies some conditions. Lastly, an example is provided to illustrate the application of the result. (general)

Measurement invariance of big-five factors over the life span: ESEM tests of gender, age, plasticity, maturity, and la dolce vita effects.

Science.gov (United States)

Marsh, Herbert W; Nagengast, Benjamin; Morin, Alexandre J S

2013-06-01

This substantive-methodological synergy applies evolving approaches to factor analysis to substantively important developmental issues of how five-factor-approach (FFA) personality measures vary with gender, age, and their interaction. Confirmatory factor analyses (CFAs) conducted at the item level often do not support a priori FFA structures, due in part to the overly restrictive assumptions of CFA models. Here we demonstrate that exploratory structural equation modeling (ESEM), an integration of CFA and exploratory factor analysis, overcomes these problems with the 15-item Big Five Inventory administered as part of the nationally representative British Household Panel Study (N = 14,021; age: 15-99 years, Mage = 47.1). ESEM fitted the data substantially better and resulted in much more differentiated (less correlated) factors than did CFA. Methodologically, we extended ESEM (introducing ESEM-within-CFA models and a hybrid of multiple groups and multiple indicators multiple causes models), evaluating full measurement invariance and latent mean differences over age, gender, and their interaction. Substantively the results showed that women had higher latent scores for all Big Five factors except for Openness and that these gender differences were consistent over the entire life span. Substantial nonlinear age effects led to the rejection of the plaster hypothesis and the maturity principle but did support a newly proposed la dolce vita effect in old age. In later years, individuals become happier (more agreeable and less neurotic), more self-content and self-centered (less extroverted and open), more laid back and satisfied with what they have (less conscientious, open, outgoing and extroverted), and less preoccupied with productivity. PsycINFO Database Record (c) 2013 APA, all rights reserved

Maximal overlap with a fully separable state and translational invariance for multipartite entangled states

International Nuclear Information System (INIS)

Cui, H. T.; Yuan Di; Tian, J. L.

2010-01-01

The maximal overlap with the fully separable state for the multipartite entangled pure state with translational invariance is studied explicitly by some exact and numerical evaluations, focusing on the one-dimensional qubit system and some representative types of translational invariance. The results show that the translational invariance of the multipartite state could have an intrinsic effect on the determination of the maximal overlap and the nearest fully separable state for multipartite entangled states. Furthermore, a hierarchy of the basic entangled states with translational invariance is found, from which one could readily find the maximal overlap and a related fully separable state for the multipartite state composed of different translational invariance structures.

Feedback-Driven Dynamic Invariant Discovery

Science.gov (United States)

Zhang, Lingming; Yang, Guowei; Rungta, Neha S.; Person, Suzette; Khurshid, Sarfraz

2014-01-01

Program invariants can help software developers identify program properties that must be preserved as the software evolves, however, formulating correct invariants can be challenging. In this work, we introduce iDiscovery, a technique which leverages symbolic execution to improve the quality of dynamically discovered invariants computed by Daikon. Candidate invariants generated by Daikon are synthesized into assertions and instrumented onto the program. The instrumented code is executed symbolically to generate new test cases that are fed back to Daikon to help further re ne the set of candidate invariants. This feedback loop is executed until a x-point is reached. To mitigate the cost of symbolic execution, we present optimizations to prune the symbolic state space and to reduce the complexity of the generated path conditions. We also leverage recent advances in constraint solution reuse techniques to avoid computing results for the same constraints across iterations. Experimental results show that iDiscovery converges to a set of higher quality invariants compared to the initial set of candidate invariants in a small number of iterations.

Measurement invariance of an instrument assessing sustainability of school-based universal behavior practices.

Science.gov (United States)

Mercer, Sterett H; McIntosh, Kent; Strickland-Cohen, M Kathleen; Horner, Robert H

2014-06-01

The purpose of the study was to examine the extent to which the School-Wide Universal Behavior Sustainability Index: School Teams (SUBSIST; McIntosh, Doolittle, Vincent, Horner, & Ervin, 2009), a measure of school and district contextual factors that promote the sustainability of school practices, demonstrated measurement invariance across groups of schools that differed in length of time implementing school-wide Positive Behavioral Interventions and Supports (PBIS; Sugai & Horner, 2009), student ethnic composition, and student socioeconomic status (SES). School PBIS team members and district coaches representing 860 schools in 14 U.S. states completed the SUBSIST. Findings supported strong measurement invariance, for all items except 1, of a model with two school-level factors (School Priority and Team Use of Data) and 2 district-level factors (District Priority and Capacity Building) across groups of schools at initial implementation, institutionalization, and sustainability phases of PBIS implementation. Schools in the sustainability phase were rated significantly higher on School Priority and Team Use of Data than schools in initial implementation. Strong measurement invariance held across groups of schools that differed in student ethnicity and SES. The findings regarding measurement invariance are important for future longitudinal investigations of factors that may promote the sustained implementation of school practices. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Assessing Measurement Invariance of the Children's Depression Inventory in Chinese and Italian Primary School Student Samples

Science.gov (United States)

Wu, Wenfeng; Lu, Yongbiao; Tan, Furong; Yao, Shuqiao; Steca, Patrizia; Abela, John R. Z.; Hankin, Benjamin L.

2012-01-01

This study tested the measurement invariance of Children's Depression Inventory (CDI) and compared its factorial variance/covariance and latent means among Chinese and Italian children. Multigroup confirmatory factor analysis of the original five factors identified by Kovacs revealed that full measurement invariance did not hold. Further analysis…

Short Is Beautiful: Dimensionality and Measurement Invariance in Two Length of the Basic Psychological Need Satisfaction at Work Scale

Directory of Open Access Journals (Sweden)

Mårten Eriksson

2018-06-01

Full Text Available Self-determination theory proposes that all humans have three intrinsic psychological needs: the needs for Autonomy, Competence, and Relatedness. These needs take different forms in different areas of life. The present study examines the psychometric properties of a Swedish version of the Basic Psychological Need Satisfaction at Work (BPNS-W scale. The fit of 10-factor structures previously suggested for related versions of the scale were compared. Cross-sectional data from 1,200 participants were examined in a confirmatory factor analysis framework. Both the original 21-item version and a reduced 12-item version of the BPNS-W were examined. The General Health Questionnaire was used for validation. The results supported a three-factor solution with correlated error variances for the reversed items. Invariance testing of the long and short scales gave best support to the short scale, for which partial scalar invariance was achieved. The external validity of the short scale was supported by a hierarchical regression analysis in which each need made a unique contribution in predicting psychological well-being. In conclusion, the results corroborate a three-factor structure of BPNS-W. Although not perfect the short scale should, it is argued, be preferred over the long version. Directions for the future development of the scale are discussed.

Structure of N = 2 superconformally invariant unitary ''minimal'' theories: Operator algebra and correlation functions

International Nuclear Information System (INIS)

Kiritsis, E.B.

1987-01-01

N = 2 superconformal-invariant theories are studied and their general structure is analyzed. The geometry of N = 2 complex superspace is developed as a tool to study the correlation functions of the theories above. The Ward identities of the global N = 2 superconformal symmetry are solved, to restrict the form of correlation functions. Advantage is taken of the existence of the degenerate operators to derive the ''fusion'' rules for the unitary minimal systems with c<1. In particular, the closure of the operator algebra for such systems is shown. The c = (1/3 minimal system is analyzed and its two-, three-, and four-point functions as well as its operator algebra are calculated explicitly

Analytic stochastic regularization and gange invariance

International Nuclear Information System (INIS)

Abdalla, E.; Gomes, M.; Lima-Santos, A.

1986-05-01

A proof that analytic stochastic regularization breaks gauge invariance is presented. This is done by an explicit one loop calculation of the vaccum polarization tensor in scalar electrodynamics, which turns out not to be transversal. The counterterm structure, Langevin equations and the construction of composite operators in the general framework of stochastic quantization, are also analysed. (Author) [pt

Gauge invariance rediscovered

International Nuclear Information System (INIS)

Moriyasu, K.

1978-01-01

A pedagogical approach to gauge invariance is presented which is based on the analogy between gauge transformations and relativity. By using the concept of an internal space, purely geometrical arguments are used to teach the physical ideas behind gauge invariance. Many of the results are applicable to general gauge theories

Improved test of Lorentz invariance in electrodynamics

International Nuclear Information System (INIS)

Wolf, Peter; Bize, Sebastien; Clairon, Andre; Santarelli, Giorgio; Tobar, Michael E.; Luiten, Andre N.

2004-01-01

We report new results of a test of Lorentz invariance based on the comparison of a cryogenic sapphire microwave resonator and a hydrogen-maser. The experimental results are shown together with an extensive analysis of systematic effects. Previously, this experiment has set the most stringent constraint on Kennedy-Thorndike type violations of Lorentz invariance. In this work we present new data and interpret our results in the general Lorentz violating extension of the standard model of particle physics (SME). Within the photon sector of the SME, our experiment is sensitive to seven SME parameters. We marginally improve present limits on four of these, and by a factor seven to ten on the other three

Webs on surfaces, rings of invariants, and clusters.

Science.gov (United States)

Fomin, Sergey; Pylyavskyy, Pavlo

2014-07-08

We construct and study cluster algebra structures in rings of invariants of the special linear group action on collections of 3D vectors, covectors, and matrices. The construction uses Kuperberg's calculus of webs on marked surfaces with boundary.

Conformal field theory on surfaces with boundaries and nondiagonal modular invariants

International Nuclear Information System (INIS)

Bern, Z.; Dunbar, D.C.

1990-01-01

This paper shows that the operator content of a conformal field theory defined on surfaces with boundaries and crosscaps is more restricted when the periodic sector is described by nondiagonal modular invariants than in the case of diagonal modular invariants. By tensoring, the restrictions can be alleviated, leading to a rich structure. Such constrictions are useful, for example, in lower- dimensional open superstring models

High Energy Astrophysics Tests of Lorentz Invariance and Quantum Gravity Models

Science.gov (United States)

Stecker, Floyd W.

2012-01-01

High energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approx.10(exp -35) m. I will discuss the possible signatures of Lorentz invariance violation (LIV) that can be manifested by observing of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) on the fraction of LIV at a Lorentz factor of approx. 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space-based detection techniques to improve searches for LIV in the future. I will also discuss how the LIV formalism casts doubt on the OPERA superluminal neutrino claim.

Construct validity, dimensionality and factorial invariance of the Rosenberg Self Esteem Scale: A bifactor modelling approach among children of prisoners

OpenAIRE

Sharratt, Kathryn; Boduszek, Daniel; Jones, Adele; Gallagher, Bernard

2014-01-01

Background The Rosenberg Self-Esteem Scale (RSES) has traditionally been conceptualised as a unidimensional measure of self-esteem, but empirical evidence is equivocal, with some studies supporting a one-factor solution and others favouring multidimensional models. Participants and procedure The aim of this study was to examine the factor structure, factorial invariance and composite reliability of the RSES within a European sample of children affected by parental imprison...

Factor structure and psychometric properties of english and spanish versions of the edinburgh postnatal depression scale among Hispanic women in a primary care setting.

Science.gov (United States)

Hartley, Chelsey M; Barroso, Nicole; Rey, Yasmin; Pettit, Jeremy W; Bagner, Daniel M

2014-12-01

Although a number of studies have examined the factor structure of the Edinburgh Postnatal Depression Scale (EPDS) in predominately White or African American samples, no published research has reported on the factor structure among Hispanic women who reside in the United States. The current study examined the factor structure of the EPDS among Hispanic mothers in the United States. Among 220 Hispanic women, drawn from a pediatric primary care setting, with an infant aged 0 to 10 months, 6 structural models guided by the empirical literature were evaluated using confirmatory factor analysis. Results supported a 2-factor model of depression and anxiety as the best fitting model. Multigroup models supported the factorial invariance across women who completed the EDPS in English and Spanish. These findings provide initial support for the 2-factor structure of the EPDS among Hispanic women in the United States. © 2014 Wiley Periodicals, Inc.

Rotation Invariance Neural Network

OpenAIRE

Li, Shiyuan

2017-01-01

Rotation invariance and translation invariance have great values in image recognition tasks. In this paper, we bring a new architecture in convolutional neural network (CNN) named cyclic convolutional layer to achieve rotation invariance in 2-D symbol recognition. We can also get the position and orientation of the 2-D symbol by the network to achieve detection purpose for multiple non-overlap target. Last but not least, this architecture can achieve one-shot learning in some cases using thos...

The Formalization of Fairness: Issues in Testing for Measurement Invariance Using Subtest Scores

Science.gov (United States)

Molenaar, Dylan; Borsboom, Denny

2013-01-01

Measurement invariance is an important prerequisite for the adequate comparison of group differences in test scores. In psychology, measurement invariance is typically investigated by means of linear factor analyses of subtest scores. These subtest scores typically result from summing the item scores. In this paper, we discuss 4 possible problems…

Renormalization-scheme-invariant QCD and QED: The method of effective charges

International Nuclear Information System (INIS)

Grunberg, G.

1984-01-01

We review, extend, and give some further applications of a method recently suggested to solve the renormalization-scheme-dependence problem in perturbative field theories. The use of a coupling constant as a universal expansion parameter is abandoned. Instead, to each physical quantity depending on a single scale variable is associated an effective charge, whose corresponding Stueckelberg--Peterman--Gell-Mann--Low function is identified as the proper object on which perturbation theory applies. Integration of the corresponding renormalization-group equations yields renormalization-scheme-invariant results free of any ambiguity related to the definition of the kinematical variable, or that of the scale parameter Λ, even though the theory is not solved to all orders. As a by-product, a renormalization-group improvement of the usual series is achieved. Extension of these methods to operators leads to the introduction of renormalization-group-invariant Green's function and Wilson coefficients, directly related to effective charges. The case of nonzero fermion masses is discussed, both for fixed masses and running masses in mass-independent renormalization schemes. The importance of the scale-invariant mass m is emphasized. Applications are given to deep-inelastic phenomena, where the use of renormalization-group-invariant coefficient functions allows to perform the factorization without having to introduce a factorization scale. The Sudakov form factor of the electron in QED is discussed as an example of an extension of the method to problems involving several momentum scales

The Dynamical Invariant of Open Quantum System

OpenAIRE

Wu, S. L.; Zhang, X. Y.; Yi, X. X.

2015-01-01

The dynamical invariant, whose expectation value is constant, is generalized to open quantum system. The evolution equation of dynamical invariant (the dynamical invariant condition) is presented for Markovian dynamics. Different with the dynamical invariant for the closed quantum system, the evolution of the dynamical invariant for the open quantum system is no longer unitary, and the eigenvalues of it are time-dependent. Since any hermitian operator fulfilling dynamical invariant condition ...

Synthesizing Modular Invariants for Synchronous Code

Directory of Open Access Journals (Sweden)

Pierre-Loic Garoche

2014-12-01

Full Text Available In this paper, we explore different techniques to synthesize modular invariants for synchronous code encoded as Horn clauses. Modular invariants are a set of formulas that characterizes the validity of predicates. They are very useful for different aspects of analysis, synthesis, testing and program transformation. We describe two techniques to generate modular invariants for code written in the synchronous dataflow language Lustre. The first technique directly encodes the synchronous code in a modular fashion. While in the second technique, we synthesize modular invariants starting from a monolithic invariant. Both techniques, take advantage of analysis techniques based on property-directed reachability. We also describe a technique to minimize the synthesized invariants.

Reducing Lookups for Invariant Checking

DEFF Research Database (Denmark)

Thomsen, Jakob Grauenkjær; Clausen, Christian; Andersen, Kristoffer Just

2013-01-01

This paper helps reduce the cost of invariant checking in cases where access to data is expensive. Assume that a set of variables satisfy a given invariant and a request is received to update a subset of them. We reduce the set of variables to inspect, in order to verify that the invariant is still...

Obsessive-compulsive symptoms in a normative Chinese sample of youth: prevalence, symptom dimensions, and factor structure of the Leyton Obsessional Inventory--Child Version.

Science.gov (United States)

Sun, Jing; Boschen, Mark J; Farrell, Lara J; Buys, Nicholas; Li, Zhan-Jiang

2014-08-01

Chinese adolescents face life stresses from multiple sources, with higher levels of stress predictive of adolescent mental health outcomes, including in the area of obsessive-compulsive disorders (OCD). Valid assessment of OCD among this age group is therefore a critical need in China. This study aims to standardise the Chinese version of the Leyton short version scale for adolescents of secondary schools in order to assess this condition. Stratified randomly selected adolescents were selected from four high schools located in Beijing, China. The Chinese version of the Leyton scale was administered to 3221 secondary school students aged between 12 and 18 years. A high response rate was achieved, with 3185 adolescents responding to the survey (98.5 percent). Exploratory factor analysis (EFA) extracted four factors from the scale: compulsive thoughts, concerns of cleanliness, lucky number, repetitiveness and repeated checking. The four-factor structures were confirmed using Confirmatory Factor Analysis (CFA). Overall the four-factor structure had a good model fit and high levels of reliability for each individual dimension and reasonable content validity. Invariance analyses in unconstrained, factor loading, and error variance models demonstrated that the Leyton scale is invariant in relation to the presence or absence OCD, age and gender. Discriminant validity analysis demonstrated that the four-factor structure scale also had excellent ability to differentiate between OCD and non-OCD students, male and female students, and age groups. The dataset was a non-clinical sample of high school students, rather than a sample of individuals with OCD. Future research may examine symptom structure in clinical populations to assess whether this structure fits into both clinical and community population. The structure derived from the Leyton short version scale in a non-clinical secondary school sample of adolescents, suggests that a four-factor solution can be utilised as a

The Italian Version of the Inventory of Interpersonal Problems (IIP-32): Psychometric Properties and Factor Structure in Clinical and Non-clinical Groups.

Science.gov (United States)

Lo Coco, Gianluca; Mannino, Giuseppe; Salerno, Laura; Oieni, Veronica; Di Fratello, Carla; Profita, Gabriele; Gullo, Salvatore

2018-01-01

All versions of the Inventory of Interpersonal Problems (IIP) are broadly used to measure people's interpersonal functioning. The aims of the current study are: (a) to examine the psychometric properties and factor structure of the Italian version of the Inventory of Interpersonal Problems-short version (IIP-32); and (b) to evaluate its associations with core symptoms of different eating disorders. One thousand two hundred and twenty three participants ( n = 623 non-clinical and n = 600 clinical participants with eating disorders and obesity) filled out the Inventory of Interpersonal Problems-short version (IIP-32) along with measures of self-esteem (Rosenberg Self-Esteem Scale, RSES), psychological functioning (Outcome Questionnaire, OQ-45), and eating disorders (Eating Disorder Inventory, EDI-3). The present study examined the eight-factor structure of the IIP-32 with Confirmatory Factor Analysis (CFA) and Exploratory Structural Equation Modeling (ESEM). ESEM was also used to test the measurement invariance of the IIP-32 across clinical and non-clinical groups. It was found that CFA had unsatisfactory model fit, whereas the corresponding ESEM solution provided a better fit to the observed data. However, six target factor loadings tend to be modest, and ten items showed cross-loadings higher than 0.30. The configural and metric invariance as well as the scalar and partial strict invariance of the IIP-32 were supported across clinical and non-clinical groups. The internal consistency of the IIP-32 was acceptable and the construct validity was confirmed by significant correlations between IIP-32, RSES, and OQ-45. Furthermore, overall interpersonal difficulties were consistently associated with core eating disorder symptoms, whereas interpersonal styles that reflect the inability to form close relationships, social awkwardness, the inability to be assertive, and a tendency to self-sacrificing were positively associated with general psychological maladjustment

The Italian Version of the Inventory of Interpersonal Problems (IIP-32: Psychometric Properties and Factor Structure in Clinical and Non-clinical Groups

Directory of Open Access Journals (Sweden)

Gianluca Lo Coco

2018-03-01

Full Text Available All versions of the Inventory of Interpersonal Problems (IIP are broadly used to measure people's interpersonal functioning. The aims of the current study are: (a to examine the psychometric properties and factor structure of the Italian version of the Inventory of Interpersonal Problems—short version (IIP-32; and (b to evaluate its associations with core symptoms of different eating disorders. One thousand two hundred and twenty three participants (n = 623 non-clinical and n = 600 clinical participants with eating disorders and obesity filled out the Inventory of Interpersonal Problems—short version (IIP-32 along with measures of self-esteem (Rosenberg Self-Esteem Scale, RSES, psychological functioning (Outcome Questionnaire, OQ-45, and eating disorders (Eating Disorder Inventory, EDI-3. The present study examined the eight-factor structure of the IIP-32 with Confirmatory Factor Analysis (CFA and Exploratory Structural Equation Modeling (ESEM. ESEM was also used to test the measurement invariance of the IIP-32 across clinical and non-clinical groups. It was found that CFA had unsatisfactory model fit, whereas the corresponding ESEM solution provided a better fit to the observed data. However, six target factor loadings tend to be modest, and ten items showed cross-loadings higher than 0.30. The configural and metric invariance as well as the scalar and partial strict invariance of the IIP-32 were supported across clinical and non-clinical groups. The internal consistency of the IIP-32 was acceptable and the construct validity was confirmed by significant correlations between IIP-32, RSES, and OQ-45. Furthermore, overall interpersonal difficulties were consistently associated with core eating disorder symptoms, whereas interpersonal styles that reflect the inability to form close relationships, social awkwardness, the inability to be assertive, and a tendency to self-sacrificing were positively associated with general psychological

Phylogenetic mixtures and linear invariants for equal input models.

Science.gov (United States)

Casanellas, Marta; Steel, Mike

2017-04-01

The reconstruction of phylogenetic trees from molecular sequence data relies on modelling site substitutions by a Markov process, or a mixture of such processes. In general, allowing mixed processes can result in different tree topologies becoming indistinguishable from the data, even for infinitely long sequences. However, when the underlying Markov process supports linear phylogenetic invariants, then provided these are sufficiently informative, the identifiability of the tree topology can be restored. In this paper, we investigate a class of processes that support linear invariants once the stationary distribution is fixed, the 'equal input model'. This model generalizes the 'Felsenstein 1981' model (and thereby the Jukes-Cantor model) from four states to an arbitrary number of states (finite or infinite), and it can also be described by a 'random cluster' process. We describe the structure and dimension of the vector spaces of phylogenetic mixtures and of linear invariants for any fixed phylogenetic tree (and for all trees-the so called 'model invariants'), on any number n of leaves. We also provide a precise description of the space of mixtures and linear invariants for the special case of [Formula: see text] leaves. By combining techniques from discrete random processes and (multi-) linear algebra, our results build on a classic result that was first established by James Lake (Mol Biol Evol 4:167-191, 1987).

The Gauge-Invariant Angular Momentum Sum-Rule for the Proton

CERN Document Server

Shore, G.M.

2000-01-01

We give a gauge-invariant treatment of the angular momentum sum-rule for the proton in terms of matrix elements of three gauge-invariant, local composite operators. These matrix elements are decomposed into three independent form factors, one of which is the flavour singlet axial charge. We further show that the axial charge cancels out of the sum-rule, so that it is unaffacted by the axial anomaly. The three form factors are then related to the four proton spin components in the parton model, namely quark and gluon intrinsic spin and orbital angular momentum. The renormalisation of the three operators is determined to one loop from which the scale dependence and mixing of the spin components is derived under the constraint that the quark spin be scale-independent. We also show how the three form factors can be measured in experiments.

Algorithms in invariant theory

CERN Document Server

Sturmfels, Bernd

2008-01-01

J. Kung and G.-C. Rota, in their 1984 paper, write: "Like the Arabian phoenix rising out of its ashes, the theory of invariants, pronounced dead at the turn of the century, is once again at the forefront of mathematics". The book of Sturmfels is both an easy-to-read textbook for invariant theory and a challenging research monograph that introduces a new approach to the algorithmic side of invariant theory. The Groebner bases method is the main tool by which the central problems in invariant theory become amenable to algorithmic solutions. Students will find the book an easy introduction to this "classical and new" area of mathematics. Researchers in mathematics, symbolic computation, and computer science will get access to a wealth of research ideas, hints for applications, outlines and details of algorithms, worked out examples, and research problems.

Empirical evidence for a four factor framework of personality disorder organization: multigroup confirmatory factor analysis of the Millon Clinical Multiaxial Inventory - III Personality Disorder Scales across Belgian and Danish data samples

DEFF Research Database (Denmark)

Rossi, Gina; Elklit, Ask; Simonsen, Erik

2010-01-01

factor models, a priori specified using structures found by Dyce, O’Connor, Parkins, and Janzen (1997), were fitted to the data. The best fitting model was a four factor structure (RMSEA = .066, GFI = .98, CFI = .93) with partially invariant factor loadings. The robustness of this four-factor model...

Factor structure of the pictorial scale of perceived competence and social acceptance with two pre-elementary samples.

Science.gov (United States)

Mantzicopoulos, Panayota; French, Brian F; Maller, Susan J

2004-01-01

Competing models of the factorial structure of the Pictorial Scale of Perceived Competence and Social Acceptance (PSPCSA) were tested for fit using multisample confirmatory factor analysis. The best fitting model was tested for invariance (a) across samples of middle-class (n = 251) and economically disadvantaged (Head Start, n = 117) kindergarten children (whose ages ranged from 67 to 86 months), and (b) over time (at the end of preschool and kindergarten) for the Head Start sample. For kindergarten children, regardless of socioeconomic status, the factor structure of the PSPCSA was consistent with the 2-factor model of Competence and Acceptance. This model also fit reasonably well for Head Start children at the end of their preschool year. However, in addition to providing broad support for the dimensionality of the measure, our findings highlight important concerns about the PSPCSA. Copyright 2004 Society for Research in Child Development, Inc.

Examining Differences in Within- and Between-Person Simple Structures of an Engineering Qualification Test Using Multilevel MIMIC Structural Equation Modeling

Directory of Open Access Journals (Sweden)

Ioannis Tsaousis

2018-02-01

Full Text Available The current study sought to meet three aims: (a to understand the optimal factor structure of the Professional Engineering (ProfEng test, a measure aiming to assess competency in engineering, within a multilevel (nested perspective; (b to examine the psychometric measurement invariance of the ProfEng test across levels due to nesting and across gender at the person level, and, (c to examine the internal consistency of the engineering competency measure at both levels in the analysis. Data involved 1,696 individuals across 21 universities who took a national licensure test as part of the professional accreditation process to obtain a work permit and practice the engineering profession in the Kingdom of Saudi Arabia. Data were analyzed by use of Multilevel Structural Equation Modeling (MLSEM. Results indicated that a 2-factor model at both levels of analysis provided the best fit to the data. We also examined violation of measurement invariance across clusters (cluster bias. Results showed that all factor loadings were invariant across levels, suggesting the presence of strong measurement invariance. Last, invariance across gender was tested by use of the MIMIC multilevel model. Results pointed to the existence of significant differences between genders on levels of personal and professional skills with females having higher levels on personal skills and males on professional. Estimates of internal consistency reliability also varied markedly due to nesting. It is concluded that ignoring a multilevel structure is associated with errors and inaccuracies in the measurement of person abilities as both measurement wise and precision wise the multilevel model provides increased accuracy at each level in the analysis.

Discover potential in a search for time-reversal invariance violation in nuclei

Energy Technology Data Exchange (ETDEWEB)

Gudkov, Vladimir, E-mail: gudkov@sc.edu; Song, Young-Ho [University of South Carolina, Department of Physics and Astronomy (United States)

2013-03-15

Time reversal invariance violating (TRIV) effects in low energy physics could be very important in searching for new physics, being complementary to neutron and atomic electric dipole moment (EDM) measurements. In this relation, we discuss a sensitivity of some TRIV observables to different models of time-reversal (CP) violation and their dependencies on nuclear structure. As a measure of a sensitivity of TRIV effects to the value of TRIV nucleon coupling constant, we introduce a coefficient of a 'discovery potential', which shows a possible factor for improving the current limits of the EDM experiments by measuring nuclear TRIV effects.

Cartan invariants and event horizon detection

Science.gov (United States)

Brooks, D.; Chavy-Waddy, P. C.; Coley, A. A.; Forget, A.; Gregoris, D.; MacCallum, M. A. H.; McNutt, D. D.

2018-04-01

We show that it is possible to locate the event horizon of a black hole (in arbitrary dimensions) by the zeros of certain Cartan invariants. This approach accounts for the recent results on the detection of stationary horizons using scalar polynomial curvature invariants, and improves upon them since the proposed method is computationally less expensive. As an application, we produce Cartan invariants that locate the event horizons for various exact four-dimensional and five-dimensional stationary, asymptotically flat (or (anti) de Sitter), black hole solutions and compare the Cartan invariants with the corresponding scalar curvature invariants that detect the event horizon.

Invariant protection of high-voltage electric motors of technological complexes at industrial enterprises at partial single-phase ground faults

Science.gov (United States)

Abramovich, B. N.; Sychev, Yu A.; Pelenev, D. N.

2018-03-01

Development results of invariant protection of high-voltage motors at incomplete single-phase ground faults are observed in the article. It is established that current protections have low action selectivity because of an inadmissible decrease in entrance signals during the shirt circuit occurrence in the place of transient resistance. The structural functional scheme and an algorithm of protective actions where correction of automatic zero sequence currents signals of the protected accessions implemented according to the level of incompleteness of ground faults are developed. It is revealed that automatic correction of zero sequence currents allows one to provide the invariance of sensitivity factor for protection under the variation conditions of a transient resistance in the place of damage. Application of invariant protection allows one to minimize damages in 6-10 kV electrical installations of industrial enterprises for a cause of infringement of consumers’ power supply and their system breakdown due to timely localization of emergency of ground faults modes.

Moment forms invariant to rotation and blur in arbitrary number of dimensions

Czech Academy of Sciences Publication Activity Database

Flusser, Jan; Boldyš, Jiří; Zitová, Barbara

2003-01-01

Roč. 25, č. 2 (2003), s. 234-246 ISSN 0162-8828 R&D Projects: GA ČR GA102/00/1711; GA ČR GP102/01/P065 Institutional research plan: CEZ:AV0Z1075907 Keywords : blur invariants * rotation invariants * group representation theory Subject RIV: JD - Computer Applications, Robotics Impact factor: 3.823, year: 2003 http://library.utia.cas.cz/prace/20030006.pdf

Mass generation within conformal invariant theories

International Nuclear Information System (INIS)

Flato, M.; Guenin, M.

1981-01-01

The massless Yang-Mills theory is strongly conformally invariant and renormalizable; however, when masses are introduced the theory becomes nonrenormalizable and weakly conformally invariant. Conditions which recover strong conformal invariance are discussed in the letter. (author)

Testing measurement invariance of composites using partial least squares

NARCIS (Netherlands)

Henseler, Jörg; Ringle, Christian M.; Sarstedt, Marko

2016-01-01

Purpose Research on international marketing usually involves comparing different groups of respondents. When using structural equation modeling (SEM), group comparisons can be misleading unless researchers establish the invariance of their measures. While methods have been proposed to analyze

Coordinate-invariant regularization

International Nuclear Information System (INIS)

Halpern, M.B.

1987-01-01

A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt Superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed. copyright 1987 Academic Press, Inc

The Basic Psychological Needs at Work Scale: Measurement Invariance between Canada and France.

Science.gov (United States)

Brien, Maryse; Forest, Jacques; Mageau, Geneviève A; Boudrias, Jean-Sébastien; Desrumaux, Pascale; Brunet, Luc; Morin, Estelle M

2012-07-01

The purpose of this study is to develop and validate the Basic Psychological Needs at Work Scale (BPNWS) in French, but items are also provided in English in the article. The BPNWS is a work-related self-report instrument designed to measure the degree to which the needs for autonomy, competence, and relatedness, as identified by Self-Determination Theory (Deci & Ryan, 2000), are satisfied at work. Using exploratory and confirmatory factor analysis, the first study examines the structure of the BPNWS in a group of 271 workers. The second study tests the measurement invariance of the scale in a group of 851 teachers from two different cultures, Canada and France. Results support the three-factor structure and show adequate internal consistency, as well as nomological validity across samples. © 2012 The Authors. Applied Psychology: Health and Well-Being © 2012 The International Association of Applied Psychology.

Gamma-Ray, Cosmic Ray and Neutrino Tests of Lorentz Invariance and Quantum Gravity Models

Science.gov (United States)

Stecker, Floyd

2011-01-01

High-energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10(exp -35) m. I will discuss here the possible signatures of Lorentz invariance violation (LIV) from observations of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) to the amount of LIV of at a proton Lorentz factor of approximately 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space based detection techniques to improve searches for LIV in the future.

What's hampering measurement invariance : Detecting non-invariant items using clusterwise simultaneous component analysis

NARCIS (Netherlands)

De Roover, K.; Timmerman, Marieke; De Leersnyder, J.; Mesquita, B.; Ceulemans, Eva

2014-01-01

The issue of measurement invariance is ubiquitous in the behavioral sciences nowadays as more and more studies yield multivariate multigroup data. When measurement invariance cannot be established across groups, this is often due to different loadings on only a few items. Within the multigroup CFA

A confining and asymptotically free solution for the renormalization group invariant charge

International Nuclear Information System (INIS)

Kellett, B.H.

1978-01-01

The central role of the invariant charge in applications of the renormalization group to quantum chromodynamics is discussed. The general structure of the invariant charge is examined, and it is shown to be a non-singular function of q 2 for all finite non-zero q 2 . At q 2 = 0 and q 2 = +or- infinity shows that QCD is asymptotically free. Some applications of these general results are discussed

Single-subject structural networks with closed-form rotation invariant matching mprove power in developmental studies of the cortex.

Science.gov (United States)

Kandel, Benjamin M; Wang, Danny J J; Gee, James C; Avants, Brian B

2014-01-01

Although much attention has recently been focused on single-subject functional networks, using methods such as resting-state functional MRI, methods for constructing single-subject structural networks are in their infancy. Single-subject cortical networks aim to describe the self-similarity across the cortical structure, possibly signifying convergent developmental pathways. Previous methods for constructing single-subject cortical networks have used patch-based correlations and distance metrics based on curvature and thickness. We present here a method for constructing similarity-based cortical structural networks that utilizes a rotation-invariant representation of structure. The resulting graph metrics are closely linked to age and indicate an increasing degree of closeness throughout development in nearly all brain regions, perhaps corresponding to a more regular structure as the brain matures. The derived graph metrics demonstrate a four-fold increase in power for detecting age as compared to cortical thickness. This proof of concept study indicates that the proposed metric may be useful in identifying biologically relevant cortical patterns.

Z3 - invariant effective theory of deconfining phase transition

International Nuclear Information System (INIS)

So, Hiroto

1986-01-01

A Z 3 -invariant scalar model is proposed as an effective theory of deconfining phase transition of QCD. Coupling constants in the potential are determined by Monte Carlo methods. The structure of renormalization trajectories for coupling constants is investigated. (author)

Validity of the Internet Addiction Test for Adolescents and Older Children (IAT-A): Tests of Measurement Invariance and Latent Mean Differences

Science.gov (United States)

Teo, Timothy; Kam, Chester

2014-01-01

Following the call to ensure the validity of instruments used to assess users' level of Internet usage, this study examined the factor structure of the Internet Addiction Test-Adolescence version (IAT-A) when applied to a sample of young children in a multicultural society and assessed whether the items in the IAT-A were invariant by gender and,…

Confirmatory factor analysis reveals a latent cognitive structure common to bipolar disorder, schizophrenia, and normal controls.

Science.gov (United States)

Schretlen, David J; Peña, Javier; Aretouli, Eleni; Orue, Izaskun; Cascella, Nicola G; Pearlson, Godfrey D; Ojeda, Natalia

2013-06-01

We sought to determine whether a single hypothesized latent factor structure would characterize cognitive functioning in three distinct groups. We assessed 576 adults (340 community controls, 126 adults with bipolar disorder, and 110 adults with schizophrenia) using 15 measures derived from nine cognitive tests. Confirmatory factor analysis (CFA) was conducted to examine the fit of a hypothesized six-factor model. The hypothesized factors included attention, psychomotor speed, verbal memory, visual memory, ideational fluency, and executive functioning. The six-factor model provided an excellent fit for all three groups [for community controls, root mean square error of approximation (RMSEA) schizophrenia, RMSEA = 0.06 and CFI = 0.98]. Alternate models that combined fluency with processing speed or verbal and visual memory reduced the goodness of fit. Multi-group CFA results supported factor invariance across the three groups. Confirmatory factor analysis supported a single six-factor structure of cognitive functioning among patients with schizophrenia or bipolar disorder and community controls. While the three groups clearly differ in level of performance, they share a common underlying architecture of information processing abilities. These cognitive factors could provide useful targets for clinical trials of treatments that aim to enhance information processing in persons with neurological and neuropsychiatric disorders. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Robust D-optimal designs under correlated error, applicable invariantly for some lifetime distributions

International Nuclear Information System (INIS)

Das, Rabindra Nath; Kim, Jinseog; Park, Jeong-Soo

2015-01-01

In quality engineering, the most commonly used lifetime distributions are log-normal, exponential, gamma and Weibull. Experimental designs are useful for predicting the optimal operating conditions of the process in lifetime improvement experiments. In the present article, invariant robust first-order D-optimal designs are derived for correlated lifetime responses having the above four distributions. Robust designs are developed for some correlated error structures. It is shown that robust first-order D-optimal designs for these lifetime distributions are always robust rotatable but the converse is not true. Moreover, it is observed that these designs depend on the respective error covariance structure but are invariant to the above four lifetime distributions. This article generalizes the results of Das and Lin [7] for the above four lifetime distributions with general (intra-class, inter-class, compound symmetry, and tri-diagonal) correlated error structures. - Highlights: • This paper presents invariant robust first-order D-optimal designs under correlated lifetime responses. • The results of Das and Lin [7] are extended for the four lifetime (log-normal, exponential, gamma and Weibull) distributions. • This paper also generalizes the results of Das and Lin [7] to more general correlated error structures

Electromagnetic Transition Form Factor of the η meson with WASA-at-COSY

Science.gov (United States)

Goswami, A.

2016-11-01

In this work we present a study of the Dalitz decay η → γe+e-. The aim of this work is to measure the transition form factor of the η meson. The transition form factor of the η meson describes the electromagnetic structure of the meson. The study of the Dalitz decay helps to calculate the transition form factor of the η meson. When a particle is point-like it's decay rate can be calculated within QED. However, the complex structure of the meson modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. For this study data on proton-proton reaction at a beam energy of 1.4 GeV has been collected with WASA-at-COSY detector at Forschungszentrum Juelich, Germany. In the higher invariant mass region recent theoretical calculations slightly deviate from the fit to the data. We expect better results in the higher invariant mass region than previous measurements. The preliminary results of the analysis will be presented.

Electromagnetic Transition Form Factor of the η meson with WASA-at-COSY

Directory of Open Access Journals (Sweden)

Goswami A.

2016-01-01

Full Text Available In this work we present a study of the Dalitz decay η → γe+e−. The aim of this work is to measure the transition form factor of the η meson. The transition form factor of the η meson describes the electromagnetic structure of the meson. The study of the Dalitz decay helps to calculate the transition form factor of the η meson. When a particle is point-like it’s decay rate can be calculated within QED. However, the complex structure of the meson modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. For this study data on proton-proton reaction at a beam energy of 1.4 GeV has been collected with WASA-at-COSY detector at Forschungszentrum Juelich, Germany. In the higher invariant mass region recent theoretical calculations slightly deviate from the fit to the data. We expect better results in the higher invariant mass region than previous measurements. The preliminary results of the analysis will be presented.

Electromagnetic transition form factor of the η meson with WASA-at-COSY

Energy Technology Data Exchange (ETDEWEB)

Goswami, Ankita [Indian Institute of Technology Indore, Indore (India); Collaboration: WASA-at-COSY-Collaboration

2015-07-01

The aim of this work is to measure the transition form factor of the η meson. The transition form factor describes the internal structure of a particle. The precise determination of the transition form factor of the η meson is possible through the η→γe{sup +} e{sup -} Dalitz decay. When a particle is point-like then its decay rate can be calculated within QED. However, the complex structure of the particle modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. η mesons are produced using the reaction pp→ppη at a beam kinetic energy of 1.4 GeV at the COSY accelerator of Forschungszentrum Juelich and decay particles of the η meson are detected with the WASA detector. In the higher invariant mass region recent theoretical calculations slightly deviate from the the data. With the high statistics dataset we expect precise results in the higher invariant mass region. The status of the analysis is reported.

Motivational Climate Sport Youth Scale: Measurement Invariance Across Gender and Five Different Sports.

Science.gov (United States)

Monteiro, Diogo; Borrego, Carla Chicau; Silva, Carlos; Moutão, João; Marinho, Daniel Almeida; Cid, Luís

2018-03-01

The aim of this study was to analyze the psychometric properties of the Portuguese version of the Motivational Climate Sport Youth Scale (MCSYSp) and invariance across gender and different sports (swimming, soccer, handball, basketball, futsal). A total of 4,569 athletes (3,053 males, 1,516 females) from soccer (1,098), swimming (1,049), basketball (1,754), futsal (340), and handball (328) participated in this study, with ages between 10 and 20 years (M = 15.13; SD = 1.95). The results show that the original model (two factors/12 items) did not adjust to the data in a satisfactory way; therefore, it was necessary to change the model by removing four items (two from each factor). Subsequently, the model adjusted to the data in a satisfactory way (χ 2 = 499.84; df = 19; χ 2 /df = 26.30; p sports (soccer, handball, basketball, futsal) (ΔCFK≤.01); however, it was not invariant between swimming and team sports (soccer, handball, basketball, futsal) (ΔCFI ≥ .01). In conclusion, the MCSYSp (two factors/eight items) is a valid and reliable choice that is transversal not only to gender, but also to the different studied team sports to measure the perception of the motivational climate in athletes. Future studies can research more deeply the invariance analysis between individual sports to better understand the invariance of the model between individual and team sports.

Assessing cross-cultural differences through use of multiple-group invariance analyses.

Science.gov (United States)

Stein, Judith A; Lee, Jerry W; Jones, Patricia S

2006-12-01

The use of structural equation modeling in cross-cultural personality research has become a popular method for testing measurement invariance. In this report, we present an example of testing measurement invariance using the Sense of Coherence Scale of Antonovsky (1993) in 3 ethnic groups: Chinese, Japanese, and Whites. In a series of increasingly restrictive constraints on the measurement models of the 3 groups, we demonstrate how to assess differences among the groups. We also provide an example of construct validation.

Colour and rotation invariant textural features based on Markov random fields

Czech Academy of Sciences Publication Activity Database

Vácha, Pavel; Haindl, Michal; Suk, Tomáš

2011-01-01

Roč. 32, č. 6 (2011), s. 771-779 ISSN 0167-8655 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image modelling * colour texture * Illumination invariance * Markov random field * rotation invariance Subject RIV: BD - Theory of Information Impact factor: 1.034, year: 2011 http://library.utia.cas.cz/separaty/2011/RO/vacha-0357314.pdf

Structure of Pioncare covariant tensor operators in quantum mechanical models

International Nuclear Information System (INIS)

Polyzou, W.N.; Klink, W.H.

1988-01-01

The structure of operators that transform covariantly in Poincare invariant quantum mechanical models is analyzed. These operators are shown to have an interaction dependence that comes from the geometry of the Poincare group. The operators can be expressed in terms of matrix elements in a complete set of eigenstates of the mass and spin operators associated with the dynamical representation of the Poincare group. The matrix elements are factored into geometrical coefficients (Clebsch--Gordan coefficients for the Poincare group) and invariant matrix elements. The geometrical coefficients are fixed by the transformation properties of the operator and the eigenvalue spectrum of the mass and spin. The invariant matrix elements, which distinguish between different operators with the same transformation properties, are given in terms of a set of invariant form factors. copyright 1988 Academic Press, Inc

Exploring the Measurement Properties of the eHealth Literacy Scale (eHEALS) Among Baby Boomers: A Multinational Test of Measurement Invariance.

Science.gov (United States)

Sudbury-Riley, Lynn; FitzPatrick, Mary; Schulz, Peter J

2017-02-27

The eHealth Literacy Scale (eHEALS) is one of only a few available measurement scales to assess eHealth literacy. Perhaps due to the relative paucity of such measures and the rising importance of eHealth literacy, the eHEALS is increasingly a choice for inclusion in a range of studies across different groups, cultures, and nations. However, despite its growing popularity, questions have been raised over its theoretical foundations, and the factorial validity and multigroup measurement properties of the scale are yet to be investigated fully. The objective of our study was to examine the factorial validity and measurement invariance of the eHEALS among baby boomers (born between 1946 and 1964) in the United States, United Kingdom, and New Zealand who had used the Internet to search for health information in the last 6 months. Online questionnaires collected data from a random sample of baby boomers from the 3 countries of interest. The theoretical underpinning to eHEALS comprises social cognitive theory and self-efficacy theory. Close scrutiny of eHEALS with analysis of these theories suggests a 3-factor structure to be worth investigating, which has never before been explored. Structural equation modeling tested a 3-factor structure based on the theoretical underpinning to eHEALS and investigated multinational measurement invariance of the eHEALS. We collected responses (N=996) to the questionnaires using random samples from the 3 countries. Results suggest that the eHEALS comprises a 3-factor structure with a measurement model that falls within all relevant fit indices (root mean square error of approximation, RMSEA=.041, comparative fit index, CFI=.986). Additionally, the scale demonstrates metric invariance (RMSEA=.040, CFI=.984, ΔCFI=.002) and even scalar invariance (RMSEA=.042, CFI=.978, ΔCFI=.008). To our knowledge, this is the first study to demonstrate multigroup factorial equivalence of the eHEALS, and did so based on data from 3 diverse nations and

Structure, longitudinal invariance, and stability of the Child Behavior Checklist 1½-5's Diagnostic and Statistical Manual of Mental Disorders-Autism Spectrum Disorder scale: Findings from Generation R (Rotterdam).

Science.gov (United States)

Rescorla, Leslie A; Ghassabian, Akhgar; Ivanova, Masha Y; Jaddoe, Vincent Wv; Verhulst, Frank C; Tiemeier, Henning

2017-11-01

Although the Child Behavior Checklist 1½-5's 12-item Diagnostic and Statistical Manual of Mental Disorders-Autism Spectrum Problems Scale (formerly called Pervasive Developmental Problems scale) has been used in several studies as an autism spectrum disorder screener, the base rate and stability of its items and its measurement model have not been previously studied. We therefore examined the structure, longitudinal invariance, and stability of the Child Behavior Checklist 1½-5's Diagnostic and Statistical Manual of Mental Disorders-Autism Spectrum Problems Scale in the diverse Generation R (Rotterdam) sample based on mothers' ratings at 18 months ( n = 4695), 3 years ( n = 4571), and 5 years ( n = 5752). Five items that seemed especially characteristic of autism spectrum disorder had low base rates at all three ages. The rank order of base rates for the 12 items was highly correlated over time ( Qs ⩾ 0.86), but the longitudinal stability of individual items was modest (phi coefficients = 0.15-0.34). Confirmatory factor analyses indicated that the autism spectrum disorder scale model manifested configural, metric, and scalar longitudinal invariance over the time period from 18 months to 5 years, with large factor loadings. Correlations over time for observed autism spectrum disorder scale scores (0.25-0.50) were generally lower than the correlations across time of the latent factors (0.45-0.68). Results indicated significant associations of the autism spectrum disorder scale with later autism spectrum disorder diagnoses.

National and Gender Measurement Invariance of the Utrecht-Management of Identity Commitments Scale (U-MICS): A 10-Nation Study With University Students.

Science.gov (United States)

Crocetti, Elisabetta; Cieciuch, Jan; Gao, Cheng-Hai; Klimstra, Theo; Lin, Ching-Ling; Matos, Paula Mena; Morsünbül, Ümit; Negru, Oana; Sugimura, Kazumi; Zimmermann, Grégoire; Meeus, Wim

2015-12-01

The purpose of this study was to examine the psychometric properties of the Utrecht-Management of Identity Commitments Scale (U-MICS), a self-report measure aimed at assessing identity processes of commitment, in-depth exploration, and reconsideration of commitment. We tested its factor structure in university students from a large array of cultural contexts, including 10 nations located in Europe (i.e., Italy, the Netherlands, Poland, Portugal, Romania, and Switzerland), Middle East (i.e., Turkey), and Asia (i.e., China, Japan, and Taiwan). Furthermore, we tested national and gender measurement invariance. Participants were 6,118 (63.2% females) university students aged from 18 to 25 years (Mage = 20.91 years). Results indicated that the three-factor structure of the U-MICS fitted well in the total sample, in each national group, and in gender groups. Furthermore, national and gender measurement invariance were established. Thus, the U-MICS can be fruitfully applied to study identity in university students from various Western and non-Western contexts. © The Author(s) 2015.

Gauge-invariant cosmological density perturbations

International Nuclear Information System (INIS)

Sasaki, Misao.

1986-06-01

Gauge-invariant formulation of cosmological density perturbation theory is reviewed with special emphasis on its geometrical aspects. Then the gauge-invariant measure of the magnitude of a given perturbation is presented. (author)

Tokunaga self-similarity arises naturally from time invariance

Science.gov (United States)

Kovchegov, Yevgeniy; Zaliapin, Ilya

2018-04-01

The Tokunaga condition is an algebraic rule that provides a detailed description of the branching structure in a self-similar tree. Despite a solid empirical validation and practical convenience, the Tokunaga condition lacks a theoretical justification. Such a justification is suggested in this work. We define a geometric branching process G (s ) that generates self-similar rooted trees. The main result establishes the equivalence between the invariance of G (s ) with respect to a time shift and a one-parametric version of the Tokunaga condition. In the parameter region where the process satisfies the Tokunaga condition (and hence is time invariant), G (s ) enjoys many of the symmetries observed in a critical binary Galton-Watson branching process and reproduces the latter for a particular parameter value.

Identification of invariant measures of interacting systems

International Nuclear Information System (INIS)

Chen Jinwen

2004-01-01

In this paper we provide an approach for identifying certain mixture representations of some invariant measures of interacting stochastic systems. This is related to the problem of ergodicity of certain extremal invariant measures that are translation invariant. Corresponding to these, results concerning the existence of invariant measures and certain weak convergence of the systems are also provided

Factor structure and reliability of the childhood trauma questionnaire and prevalence estimates of trauma for male and female street youth.

Science.gov (United States)

Forde, David R; Baron, Stephen W; Scher, Christine D; Stein, Murray B

2012-01-01

This study examines the psychometric properties of the Childhood Trauma Questionnaire short form (CTQ-SF) with street youth who have run away or been expelled from their homes (N = 397). Internal reliability coefficients for the five clinical scales ranged from .65 to .95. Confirmatory Factor Analysis (CFA) was used to test the five-factor structure of the scales yielding acceptable fit for the total sample. Additional multigroup analyses were performed to consider items by gender. Results provided only evidence of weak factorial invariance. Constrained models showed invariance in configuration, factor loadings, and factor covariances but failed for equality of intercepts. Mean trauma scores for street youth tended to fall in the moderate to severe range on all abuse/neglect clinical scales. Females reported higher levels of abuse and neglect. Prevalence of child maltreatment of individual forms was very high with 98% of street youth reporting one or more forms; 27.4% of males and 48.9% of females reported all five forms. Results of this study support the viability of the CTQ-SF for screening maltreatment in a highly vulnerable street population. Caution is recommended when comparing prevalence estimates for male and female street youth given the failure of the strong factorial multigroup model.

Modularization of biochemical networks based on classification of Petri net t-invariants.

Science.gov (United States)

Grafahrend-Belau, Eva; Schreiber, Falk; Heiner, Monika; Sackmann, Andrea; Junker, Björn H; Grunwald, Stefanie; Speer, Astrid; Winder, Katja; Koch, Ina

2008-02-08

Structural analysis of biochemical networks is a growing field in bioinformatics and systems biology. The availability of an increasing amount of biological data from molecular biological networks promises a deeper understanding but confronts researchers with the problem of combinatorial explosion. The amount of qualitative network data is growing much faster than the amount of quantitative data, such as enzyme kinetics. In many cases it is even impossible to measure quantitative data because of limitations of experimental methods, or for ethical reasons. Thus, a huge amount of qualitative data, such as interaction data, is available, but it was not sufficiently used for modeling purposes, until now. New approaches have been developed, but the complexity of data often limits the application of many of the methods. Biochemical Petri nets make it possible to explore static and dynamic qualitative system properties. One Petri net approach is model validation based on the computation of the system's invariant properties, focusing on t-invariants. T-invariants correspond to subnetworks, which describe the basic system behavior.With increasing system complexity, the basic behavior can only be expressed by a huge number of t-invariants. According to our validation criteria for biochemical Petri nets, the necessary verification of the biological meaning, by interpreting each subnetwork (t-invariant) manually, is not possible anymore. Thus, an automated, biologically meaningful classification would be helpful in analyzing t-invariants, and supporting the understanding of the basic behavior of the considered biological system. Here, we introduce a new approach to automatically classify t-invariants to cope with network complexity. We apply clustering techniques such as UPGMA, Complete Linkage, Single Linkage, and Neighbor Joining in combination with different distance measures to get biologically meaningful clusters (t-clusters), which can be interpreted as modules. To find

Modularization of biochemical networks based on classification of Petri net t-invariants

Directory of Open Access Journals (Sweden)

Grunwald Stefanie

2008-02-01

Full Text Available Abstract Background Structural analysis of biochemical networks is a growing field in bioinformatics and systems biology. The availability of an increasing amount of biological data from molecular biological networks promises a deeper understanding but confronts researchers with the problem of combinatorial explosion. The amount of qualitative network data is growing much faster than the amount of quantitative data, such as enzyme kinetics. In many cases it is even impossible to measure quantitative data because of limitations of experimental methods, or for ethical reasons. Thus, a huge amount of qualitative data, such as interaction data, is available, but it was not sufficiently used for modeling purposes, until now. New approaches have been developed, but the complexity of data often limits the application of many of the methods. Biochemical Petri nets make it possible to explore static and dynamic qualitative system properties. One Petri net approach is model validation based on the computation of the system's invariant properties, focusing on t-invariants. T-invariants correspond to subnetworks, which describe the basic system behavior. With increasing system complexity, the basic behavior can only be expressed by a huge number of t-invariants. According to our validation criteria for biochemical Petri nets, the necessary verification of the biological meaning, by interpreting each subnetwork (t-invariant manually, is not possible anymore. Thus, an automated, biologically meaningful classification would be helpful in analyzing t-invariants, and supporting the understanding of the basic behavior of the considered biological system. Methods Here, we introduce a new approach to automatically classify t-invariants to cope with network complexity. We apply clustering techniques such as UPGMA, Complete Linkage, Single Linkage, and Neighbor Joining in combination with different distance measures to get biologically meaningful clusters (t

Electromagnetic properties of off-shell particles and gauge invariance

NARCIS (Netherlands)

Nagorny, S. I.; Dieperink, A. E. L.

1998-01-01

Abstract: Electromagnetic properties of off-shell particles are discussed on the basis of a purely electromagnetic reaction: virtual Compton scattering off a proton. It is shown that the definition of off-shell electromagnetic form factors is not gauge invariant and that these cannot be investigated

Factor structure and psychometric properties of a Spanish translation of the Body Appreciation Scale-2 (BAS-2).

Science.gov (United States)

Swami, Viren; García, Antonio Alías; Barron, David

2017-09-01

We examined the psychometric properties of a Spanish translation of the Body Appreciation Scale-2 (BAS-2) in a community sample of 411 women and 389 men in Almería, Spain. Participants completed the 10-item BAS-2 along with measures of appearance evaluation, body areas satisfaction, self-esteem, life satisfaction, and self-reported body mass index (BMI). Exploratory factor analyses with one split-half subsample revealed that BAS-2 scores had a one-dimensional factor structure in women and men. Confirmatory factor analysis with a second split-half subsample showed the one-dimensional factor structure had acceptable fit and was invariant across sex. There were no significant sex differences in BAS-2 scores. BAS-2 scores were significantly and positively correlated with appearance evaluation, body areas satisfaction, self-esteem, and life satisfaction. Body appreciation was significantly and negatively correlated with BMI in men, but associations in women were only significant in the second subsample. Results suggest that the Spanish BAS-2 has adequate psychometric properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Constructing Invariant Fairness Measures for Surfaces

DEFF Research Database (Denmark)

Gravesen, Jens; Ungstrup, Michael

1998-01-01

of the size of this vector field is used as the fairness measure on the family.Six basic 3rd order invariants satisfying two quadratic equations are defined. They form a complete set in the sense that any invariant 3rd order function can be written as a function of the six basic invariants together...

On logarithmic extensions of local scale-invariance

International Nuclear Information System (INIS)

Henkel, Malte

2013-01-01

Ageing phenomena far from equilibrium naturally present dynamical scaling and in many situations this may be generalised to local scale-invariance. Generically, the absence of time-translation-invariance implies that each scaling operator is characterised by two independent scaling dimensions. Building on analogies with logarithmic conformal invariance and logarithmic Schrödinger-invariance, this work proposes a logarithmic extension of local scale-invariance, without time-translation-invariance. Carrying this out requires in general to replace both scaling dimensions of each scaling operator by Jordan cells. Co-variant two-point functions are derived for the most simple case of a two-dimensional logarithmic extension. Their form is compared to simulational data for autoresponse functions in several universality classes of non-equilibrium ageing phenomena

Nonlocal, yet translation invariant, constraints for rotationally invariant slave bosons

Science.gov (United States)

Ayral, Thomas; Kotliar, Gabriel

The rotationally-invariant slave boson (RISB) method is a lightweight framework allowing to study the low-energy properties of complex multiorbital problems currently out of the reach of more comprehensive, yet more computationally demanding methods such as dynamical mean field theory. In the original formulation of this formalism, the slave-boson constraints can be made nonlocal by enlarging the unit cell and viewing the quantum states enclosed in this new unit cell as molecular levels. In this work, we extend RISB to constraints which are nonlocal while preserving translation invariance. We apply this extension to the Hubbard model.

E7 type modular invariant Wess-Zumino theory and Gepner's string compactification

International Nuclear Information System (INIS)

Kato, Akishi; Kitazawa, Yoshihisa

1989-01-01

The report addresses the development of a general procedure to study the structure of operator algebra in off-diagonal modular invariant theories. An effort is made to carry out this procedure in E 7 type modular invariant Wess-Zumino-Witten theory and explicitly check the closure of operator product algebra, which is required for any consistent conformal field theory. The conformal field theory is utilized to construct perturbative vacuum in string theory. Apparently quite nontrivial vacuums can be constructed out of minimal models of the N = 2 superconformal theory. Here, an investigation made of the Yukawa couplings of such a model which uses E 7 type off-diagonal modular invariance. Phenomenological properties of this model is also discussed. Although off-diagonal modular invariant theories are rather special, realistic models seem to require very special manifolds. Therefore they may enhance the viability of string theory to describe real world. A study is also made on Verlinde's fusion algebra in E 7 modular invariant theory. It is determined in the holomorphic sector only. Furthermore the indicator is given by the modular transformation matrix. A pair of operators which operate on the characters play a crucial role in this theory. (Nogami, K.)

The Chinese Intelligence Scale for Young Children: Testing Factor Structure and Measurement Invariance Using the Framework of the Wechsler Intelligence Tests

Science.gov (United States)

Guo, Boliang; Aveyard, Paul; Dai, Xiaoyang

2009-01-01

The Wechsler intelligence test has four factors representing four components of intellectual function. In China, there are marked cultural, educational, and economic disparities between rural and urban dwellers, which could lead to cultural bias. The aim of this study was to apply the four-factor structure to responses to the Chinese Intelligence…

The extended local gauge invariance and the BRS symmetry in stochastic quantization of gauge fields

International Nuclear Information System (INIS)

Nakazawa, Naohito.

1989-05-01

We investigate the BRS invariance of the first-class constrained systems in the context of the stochastic quantization. For the first-class constrained systems, we construct the nilpotent BRS transformation and the BRS invariant stochastic effective action based on the D+1 dimensional field theoretical formulation of stochastic quantization. By eliminating the multiplier field of the gauge fixing condition and an auxiliary field, it is shown that there exists a truncated BRS transformation which satisfies the nilpotency condition. The truncated BRS invariant stochastic action is also derived. As the examples of the general formulation, we investigate the BRS invariant structure in the massless and massive Yang-Mills fields in stochastic quantization. (author)

Scale invariants from Gaussian-Hermite moments

Czech Academy of Sciences Publication Activity Database

Yang, B.; Kostková, Jitka; Flusser, Jan; Suk, Tomáš

2017-01-01

Roč. 132, č. 1 (2017), s. 77-84 ISSN 0165-1684 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Scale invariants * Gaussian–Hermite moments * Variable modulation * Normalization * Zernike moments Subject RIV: JD - Computer Applications, Robotics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 3.110, year: 2016 http://library.utia.cas.cz/separaty/2016/ZOI/flusser-0466031.pdf

Invariant measures of mass migration processes

Czech Academy of Sciences Publication Activity Database

Fajfrová, Lucie; Gobron, T.; Saada, E.

2016-01-01

Roč. 21, č. 1 (2016), s. 1-52, č. článku 60. ISSN 1083-6489 R&D Projects: GA ČR GAP201/12/2613; GA ČR(CZ) GA16-15238S Institutional support: RVO:67985556 Keywords : interacting particle systems * product invariant measures * zero range process * target process * mass migration process * condensation Subject RIV: BA - General Mathematics Impact factor: 0.904, year: 2016 http://library.utia.cas.cz/separaty/2016/SI/fajfrova-0464455.pdf

Psychometric properties of the Perceived Stress Scale (PSS: measurement invariance between athletes and non-athletes and construct validity

Directory of Open Access Journals (Sweden)

Yi-Hsiang Chiu

2016-12-01

Full Text Available Background Although Perceived Stress Scale (PSS, Cohen, Kamarack & Mermelstein, 1983 has been validated and widely used in many domains, there is still no validation in sports by comparing athletes and non-athletes and examining related psychometric indices. Purpose The purpose of this study was to examine the measurement invariance of PSS between athletes and non-athletes, and examine construct validity and reliability in the sports contexts. Methods Study 1 sampled 359 college student-athletes (males = 233; females = 126 and 242 non-athletes (males = 124; females = 118 and examined factorial structure, measurement invariance and internal consistency. Study 2 sampled 196 student-athletes (males = 139, females = 57, Mage = 19.88 yrs, SD = 1.35 and examined discriminant validity and convergent validity of PSS. Study 3 sampled 37 student-athletes to assess test-retest reliability of PSS. Results Results found that 2-factor PSS-10 fitted the model the best and had appropriate reliability. Also, there was a measurement invariance between athletes and non-athletes; and PSS positively correlated with athletic burnout and life stress but negatively correlated with coping efficacy provided evidence of discriminant validity and convergent validity. Further, the test-retest reliability for PSS subscales was significant (r = .66 and r = .50. Discussion It is suggested that 2-factor PSS-10 can be a useful tool in assessing perceived stress either in sports or non-sports settings. We suggest future study may use 2-factor PSS-10 in examining the effects of stress on the athletic injury, burnout, and psychiatry disorders.

A more general model for testing measurement invariance and differential item functioning.

Science.gov (United States)

Bauer, Daniel J

2017-09-01

The evaluation of measurement invariance is an important step in establishing the validity and comparability of measurements across individuals. Most commonly, measurement invariance has been examined using 1 of 2 primary latent variable modeling approaches: the multiple groups model or the multiple-indicator multiple-cause (MIMIC) model. Both approaches offer opportunities to detect differential item functioning within multi-item scales, and thereby to test measurement invariance, but both approaches also have significant limitations. The multiple groups model allows 1 to examine the invariance of all model parameters but only across levels of a single categorical individual difference variable (e.g., ethnicity). In contrast, the MIMIC model permits both categorical and continuous individual difference variables (e.g., sex and age) but permits only a subset of the model parameters to vary as a function of these characteristics. The current article argues that moderated nonlinear factor analysis (MNLFA) constitutes an alternative, more flexible model for evaluating measurement invariance and differential item functioning. We show that the MNLFA subsumes and combines the strengths of the multiple group and MIMIC models, allowing for a full and simultaneous assessment of measurement invariance and differential item functioning across multiple categorical and/or continuous individual difference variables. The relationships between the MNLFA model and the multiple groups and MIMIC models are shown mathematically and via an empirical demonstration. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Substance Use and Depression Symptomatology: Measurement Invariance of the Beck Depression Inventory (BDI-II among Non-Users and Frequent-Users of Alcohol, Nicotine and Cannabis.

Directory of Open Access Journals (Sweden)

Ashlee A Moore

Full Text Available Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.

Substance Use and Depression Symptomatology: Measurement Invariance of the Beck Depression Inventory (BDI-II) among Non-Users and Frequent-Users of Alcohol, Nicotine and Cannabis.

Science.gov (United States)

Moore, Ashlee A; Neale, Michael C; Silberg, Judy L; Verhulst, Brad

2016-01-01

Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II) in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.

Analytic invariants of boundary links

OpenAIRE

Garoufalidis, Stavros; Levine, Jerome

2001-01-01

Using basic topology and linear algebra, we define a plethora of invariants of boundary links whose values are power series with noncommuting variables. These turn out to be useful and elementary reformulations of an invariant originally defined by M. Farber.

Status of time reversal invariance

International Nuclear Information System (INIS)

Henley, E.M.

1989-01-01

Time Reversal Invariance is introduced, and theories for its violation are reviewed. The present experimental and theoretical status of Time Reversal Invariance and tests thereof will be presented. Possible future tests will be discussed. 30 refs., 2 figs., 1 tab

Summational invariants

International Nuclear Information System (INIS)

Mackrodt, C.; Reeh, H.

1997-01-01

General summational invariants, i.e., conservation laws acting additively on asymptotic particle states, are investigated within a classical framework for point particles with nontrivial scattering. copyright 1997 American Institute of Physics

Link invariants for flows in higher dimensions

International Nuclear Information System (INIS)

Garcia-Compean, Hugo; Santos-Silva, Roberto

2010-01-01

Linking numbers in higher dimensions and their generalization including gauge fields are studied in the context of BF theories. The linking numbers associated with n-manifolds with smooth flows generated by divergence-free p-vector fields, endowed with an invariant flow measure, are computed in the context of quantum field theory. They constitute invariants of smooth dynamical systems (for nonsingular flows) and generalize previous proposals of invariants. In particular, they generalize Arnold's asymptotic Hopf invariant from three to higher dimensions. This invariant is generalized by coupling with a non-Abelian gauge flat connection with nontrivial holonomy. The computation of the asymptotic Jones-Witten invariants for flows is naturally extended to dimension n=2p+1. Finally, we give a possible interpretation and implementation of these issues in the context of 11-dimensional supergravity and string theory.

Improved medical image fusion based on cascaded PCA and shift invariant wavelet transforms.

Science.gov (United States)

Reena Benjamin, J; Jayasree, T

2018-02-01

In the medical field, radiologists need more informative and high-quality medical images to diagnose diseases. Image fusion plays a vital role in the field of biomedical image analysis. It aims to integrate the complementary information from multimodal images, producing a new composite image which is expected to be more informative for visual perception than any of the individual input images. The main objective of this paper is to improve the information, to preserve the edges and to enhance the quality of the fused image using cascaded principal component analysis (PCA) and shift invariant wavelet transforms. A novel image fusion technique based on cascaded PCA and shift invariant wavelet transforms is proposed in this paper. PCA in spatial domain extracts relevant information from the large dataset based on eigenvalue decomposition, and the wavelet transform operating in the complex domain with shift invariant properties brings out more directional and phase details of the image. The significance of maximum fusion rule applied in dual-tree complex wavelet transform domain enhances the average information and morphological details. The input images of the human brain of two different modalities (MRI and CT) are collected from whole brain atlas data distributed by Harvard University. Both MRI and CT images are fused using cascaded PCA and shift invariant wavelet transform method. The proposed method is evaluated based on three main key factors, namely structure preservation, edge preservation, contrast preservation. The experimental results and comparison with other existing fusion methods show the superior performance of the proposed image fusion framework in terms of visual and quantitative evaluations. In this paper, a complex wavelet-based image fusion has been discussed. The experimental results demonstrate that the proposed method enhances the directional features as well as fine edge details. Also, it reduces the redundant details, artifacts, distortions.

Dynamical topological invariant after a quantum quench

Science.gov (United States)

Yang, Chao; Li, Linhu; Chen, Shu

2018-02-01

We show how to define a dynamical topological invariant for one-dimensional two-band topological systems after a quantum quench. By analyzing general two-band models of topological insulators, we demonstrate that the reduced momentum-time manifold can be viewed as a series of submanifolds S2, and thus we are able to define a dynamical topological invariant on each of the spheres. We also unveil the intrinsic relation between the dynamical topological invariant and the difference in the topological invariant of the initial and final static Hamiltonian. By considering some concrete examples, we illustrate the calculation of the dynamical topological invariant and its geometrical meaning explicitly.

Age-related invariance of abilities measured with the Wechsler Adult Intelligence Scale-IV.

Science.gov (United States)

Sudarshan, Navaneetham J; Bowden, Stephen C; Saklofske, Donald H; Weiss, Lawrence G

2016-11-01

Assessment of measurement invariance across populations is essential for meaningful comparison of test scores, and is especially relevant where repeated measurements are required for educational assessment or clinical diagnosis. Establishing measurement invariance legitimizes the assumption that test scores reflect the same psychological trait in different populations or across different occasions. Examination of Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) U.S. standardization samples revealed that a first-order 5-factor measurement model was best fitting across 9 age groups from 16 years to 69 years. Strong metric invariance was found for 3 of 5 factors and partial intercept invariance for the remaining 2. Pairwise comparisons of adjacent age groups supported the inference that cognitive-trait group differences are manifested by group differences in the test scores. In educational and clinical settings these findings provide theoretical and empirical support to interpret changes in the index or subtest scores as reflecting changes in the corresponding cognitive abilities. Further, where clinically relevant, the subtest score composites can be used to compare changes in respective cognitive abilities. The model was supported in the Canadian standardization data with pooled age groups but the sample sizes were not adequate for detailed examination of separate age groups in the Canadian sample. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Quantifying Translation-Invariance in Convolutional Neural Networks

OpenAIRE

Kauderer-Abrams, Eric

2017-01-01

A fundamental problem in object recognition is the development of image representations that are invariant to common transformations such as translation, rotation, and small deformations. There are multiple hypotheses regarding the source of translation invariance in CNNs. One idea is that translation invariance is due to the increasing receptive field size of neurons in successive convolution layers. Another possibility is that invariance is due to the pooling operation. We develop a simple ...

Replication of a Modified Factor Structure for the Eating Disorder Examination-Questionnaire: Extension to Clinical Eating Disorder and Non-clinical Samples in Portugal.

Science.gov (United States)

Machado, Paulo P P; Grilo, Carlos M; Crosby, Ross D

2018-01-01

Psychometric investigations of the Eating Disorder Examination-Questionnaire (EDE-Q) have generally not supported the original scale structure. The present study tested an alternative brief factor structure in two large Portuguese samples: (1) a non-clinical sample of N = 4117 female students and (2) a treatment-seeking sample of N = 609 patients diagnosed with eating disorders. Confirmatory factor analysis revealed a poor fit for the original EDE-Q structure in both the non-clinical and the clinical samples but revealed a good fit for the alternative 7-item 3-factor structure (dietary restraint, shape/weight overvaluation and body dissatisfaction). Factor loadings were invariant across samples and across the different specific eating disorder diagnoses in the clinical sample. These confirmatory factor analysis findings, which replicate findings from studies with diverse predominately overweight/obese samples, supported a modified 7-item, 3-factor structure for the EDE-Q. The reliable findings across different non-clinical and clinical eating disorder groups provide confidence regarding the potential utility of this brief version. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Effect of silhouetting and inversion on view invariance in the monkey inferotemporal cortex.

Science.gov (United States)

Ratan Murty, N Apurva; Arun, S P

2017-07-01

We effortlessly recognize objects across changes in viewpoint, but we know relatively little about the features that underlie viewpoint invariance in the brain. Here, we set out to characterize how viewpoint invariance in monkey inferior temporal (IT) neurons is influenced by two image manipulations-silhouetting and inversion. Reducing an object into its silhouette removes internal detail, so this would reveal how much viewpoint invariance depends on the external contours. Inverting an object retains but rearranges features, so this would reveal how much viewpoint invariance depends on the arrangement and orientation of features. Our main findings are 1 ) view invariance is weakened by silhouetting but not by inversion; 2 ) view invariance was stronger in neurons that generalized across silhouetting and inversion; 3 ) neuronal responses to natural objects matched early with that of silhouettes and only later to that of inverted objects, indicative of coarse-to-fine processing; and 4 ) the impact of silhouetting and inversion depended on object structure. Taken together, our results elucidate the underlying features and dynamics of view-invariant object representations in the brain. NEW & NOTEWORTHY We easily recognize objects across changes in viewpoint, but the underlying features are unknown. Here, we show that view invariance in the monkey inferotemporal cortex is driven mainly by external object contours and is not specialized for object orientation. We also find that the responses to natural objects match with that of their silhouettes early in the response, and with inverted versions later in the response-indicative of a coarse-to-fine processing sequence in the brain. Copyright © 2017 the American Physiological Society.

New approach to invariant-embedding methods in reactor physics calculations

International Nuclear Information System (INIS)

Forsbacka, M.J.; Rydin, R.A.

1997-01-01

Invariant-embedding methods offer an alternative approach to modeling physical phenomena and solving mathematical problems. Invariant embedding allows one to express traditional boundary-value problems as initial-value problems. In doing this, one effectively reformulates a problem to be solved in terms of an embedding parameter. In this paper, a hybrid method that consists of Monte Carlo-generated response functions that describe the neutronic properties of local spatial cells are coupled together in a global reactor model using the invariant embedding methodology, where the system multiplication factor k eff is used as the embedding parameter. Thus, k eff is computed directly rather than as the result of a secondary eigenvalue calculation. Because the response functions can represent any arbitrary material distribution within a local cell, this method shows promise to accurately assess the change in reactivity due to core disruptive accidents and other changes in system configuration such as changing control rod positions. This paper reports a series of proof-of-concept calculations that assess this method

Invariant measures in brain dynamics

International Nuclear Information System (INIS)

Boyarsky, Abraham; Gora, Pawel

2006-01-01

This note concerns brain activity at the level of neural ensembles and uses ideas from ergodic dynamical systems to model and characterize chaotic patterns among these ensembles during conscious mental activity. Central to our model is the definition of a space of neural ensembles and the assumption of discrete time ensemble dynamics. We argue that continuous invariant measures draw the attention of deeper brain processes, engendering emergent properties such as consciousness. Invariant measures supported on a finite set of ensembles reflect periodic behavior, whereas the existence of continuous invariant measures reflect the dynamics of nonrepeating ensemble patterns that elicit the interest of deeper mental processes. We shall consider two different ways to achieve continuous invariant measures on the space of neural ensembles: (1) via quantum jitters, and (2) via sensory input accompanied by inner thought processes which engender a 'folding' property on the space of ensembles

Longitudinal and dynamic measurement invariance of the FACIT-Fatigue scale: an application of the measurement model of derivatives to ECOG-ACRIN study E2805.

Science.gov (United States)

Estabrook, Ryne; Cella, David; Zhao, Fengmin; Manola, Judith; DiPaola, Robert S; Wagner, Lynne I; Haas, Naomi B

2018-03-05

While quality of life measures may be used to assess meaningful change and group differences, their scaling and validation often rely on a single occasion of measurement. Using the 13-item FACIT-Fatigue questionnaire at three timepoints, this study tests whether individual items change together in ways consistent with a general fatigue factor. The measurement model of derivatives (MMOD) is a novel method for measurement evaluation that directly assesses whether a given factor structure accurately describes how individual test items change over time. MMOD transforms item-level longitudinal data into a set of orthogonal change scores, each one representing either a within-person longitudinal mean or a different type of longitudinal change. These change scores are then factor analyzed and tested for invariance. This approach is applied to the FACIT-Fatigue scale in a sample of patients with renal cell carcinoma treated on 'ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) study 2805. Analyses revealed strong evidence of unidimensionality, and apparent factorial invariance using traditional techniques. MMOD revealed a small but statistically significant difference in factor structure ([Formula: see text], [Formula: see text]), where factor loadings were weaker and more variable for measuring longitudinal change. The differences in factor structure were not large enough to substantially affect scale usage in this application, but they do reveal some variability across items in the FACIT-Fatigue in their ability to detect change. Future applications should consider differential sensitivity of individual items in multi-item scales, and perhaps even capitalize upon these differences by selecting items that are more sensitive to change.

Renormalization scheme invariant predictions for deep-inelastic scattering and determination of ΛQCD

International Nuclear Information System (INIS)

Vovk, V.I.

1989-01-01

Theoretical aspects of the renormalization scheme (RS) ambiguity problem and the approaches to its solution are discussed from the point of view of QCD phenomenology and the scale Λ determination. The method of RS-invariant perturbation theory (RSIPT) as a sound basis for describing experiment in QCD is advocated. To this end the method is developed for the non-singlet structure functions (SF) of deep-inelastic scattering and recent high precision data on SF's are analyzed in a RS-invariant way. It is shown that RSIPT leads to a more accurate and reliable determination of the QCD scale Λ, which is consistent with the theoretical assumption of a better convergence of RS-invariant perturbative series. 24 refs.; 1 tab

Search for Structure in the Bs0 π± Invariant Mass Spectrum

NARCIS (Netherlands)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; Everse, LA; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J.E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Batsukh, B.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Betti, F.; Bettler, M-O.; Van Beuzekom, Martin; Bezshyiko, I.; Bifani, S.; Billoir, P.; Bird, T.D.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Borgheresi, A.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S-F.; Chobanova, V.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, C.R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Dall'Occo, E.; Dalseno, J.; David, P. N.Y.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; de Miranda, J. M.; Paula, L.E.; De Serio, M.; De Simone, P.; Dean, C-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dungs, K.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Déléage, N.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T. M.; Falabella, A.; Farley, N.; Farry, S.; Fay, R.; Fazzini, D.; Ferguson, D.; Fernandez Albor, V.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, Mark; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Furfaro, E.; Färber, C.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Carvalho-Gaspar, M.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T. J.; Ghez, Ph; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.Q.; Gorelov, I. V.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Griffith, P.; Grillo, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hatch, M.J.; He, J.; Head, T.; Heister, A.J.G.A.M.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hussain, N.; Hutchcroft, D. E.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kecke, M.; Kelsey, M. H.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.M.; Klimaszewski, K.; Koliiev, S.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kozachuk, A.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G. D.; Lai, A.; Lambert, D.M.; Lanfranchi, G.; Langenbruch, C.; Latham, T. E.; Lazzeroni, C.; Le Gac, R.; Van Leerdam, J.; Lees, J. P.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Lindner, R.; Linn, S.C.; Lionetto, F.; Liu, B.; Liu, X.; Loh, D.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli-Boneschi, F.; Martinez-Santos, D.; Martinez-Vidal, F.; Martins Tostes, D.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; Mcnab, A.; McNulty, R.; Meadows, B. T.; Meier, F.; Meissner, M.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Minard, M. N.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Mussini, M.; Müller, D.; Müller, J.; Müller, Karl; von Müller, L.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J.G.; Otalora Goicochea, J. M.; Otto, E.A.; Owen, R.P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L.L.; Parker, W.S; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, D.A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Popov, A.; Popov, D.; Popovici, B.; Poslavskii, S.; Potterat, C.; Price, M. E.; Price, J.D.; Prisciandaro, J.; Pritchard, C.A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, Y.W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Raven, G.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, Jennifer S; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, L.E.T.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Rogozhnikov, A.; Roiser, S.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, R. H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubert, K.; Schubiger, M.; Schune, M. H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sergi, A; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stevenson-Moore, P.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; Van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M. N.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Toriello, F.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Traill, M.; Tran, N.T.M.T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, M.A.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valat, S.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel-Plandsoen, M.M.; Velthuis, M.J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Vernet, M.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Volkov, V.; Vollhardt, A.; Voneki, B.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; De Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, John; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M.P.; Williams, M.; Williams, T.; Wilson, James F; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wright, S.J.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yin, H; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhokhov, A.; Zhu, X.; Zhukov, V.; Zucchelli, S.

2016-01-01

The Bs0π± invariant mass distribution is investigated in order to search for possible exotic meson states. The analysis is based on a data sample recorded with the LHCb detector corresponding to 3 fb-1 of pp collision data at s=7 and 8 TeV. No significant excess is found, and upper limits are set on

The usage of color invariance in SURF

Science.gov (United States)

Meng, Gang; Jiang, Zhiguo; Zhao, Danpei

2009-10-01

SURF (Scale Invariant Feature Transform) is a robust local invariant feature descriptor. However, SURF is mainly designed for gray images. In order to make use of the information provided by color (mainly RGB channels), this paper presents a novel colored local invariant feature descriptor, CISURF (Color Invariance based SURF). The proposed approach builds the descriptors in a color invariant space, which stems from Kubelka-Munk model and provides more valuable information than the gray space. Compared with the conventional SURF and SIFT descriptors, the experimental results show that descriptors created by CISURF is more robust to the circumstance changes such as the illumination direction, illumination intensity, and the viewpoints, and are more suitable for the deep space background objects.

The classification problem for von Neumann factors

DEFF Research Database (Denmark)

Sasyk, R.; Törnquist, Asger Dag

2009-01-01

We prove that it is not possible to classify separable von Neumann factors of types II, II or III, 0 ≤ λ ≤ 1, up to isomorphism by a Borel measurable assignment of "countable structures" as invariants. In particular the isomorphism relation of type II factors is not smooth. We also prove...... that the isomorphism relation for von Neumann II factors is analytic, but is not Borel....

Anisotropic Weyl invariance

Energy Technology Data Exchange (ETDEWEB)

Perez-Nadal, Guillem [Universidad de Buenos Aires, Buenos Aires (Argentina)

2017-07-15

We consider a non-relativistic free scalar field theory with a type of anisotropic scale invariance in which the number of coordinates ''scaling like time'' is generically greater than one. We propose the Cartesian product of two curved spaces, the metric of each space being parameterized by the other space, as a notion of curved background to which the theory can be extended. We study this type of geometries, and find a family of extensions of the theory to curved backgrounds in which the anisotropic scale invariance is promoted to a local, Weyl-type symmetry. (orig.)

The invariant theory of matrices

CERN Document Server

Concini, Corrado De

2017-01-01

This book gives a unified, complete, and self-contained exposition of the main algebraic theorems of invariant theory for matrices in a characteristic free approach. More precisely, it contains the description of polynomial functions in several variables on the set of m\\times m matrices with coefficients in an infinite field or even the ring of integers, invariant under simultaneous conjugation. Following Hermann Weyl's classical approach, the ring of invariants is described by formulating and proving the first fundamental theorem that describes a set of generators in the ring of invariants, and the second fundamental theorem that describes relations between these generators. The authors study both the case of matrices over a field of characteristic 0 and the case of matrices over a field of positive characteristic. While the case of characteristic 0 can be treated following a classical approach, the case of positive characteristic (developed by Donkin and Zubkov) is much harder. A presentation of this case...

A cognitive-affective system theory of personality: reconceptualizing situations, dispositions, dynamics, and invariance in personality structure.

Science.gov (United States)

Mischel, W; Shoda, Y

1995-04-01

A theory was proposed to reconcile paradoxical findings on the invariance of personality and the variability of behavior across situations. For this purpose, individuals were assumed to differ in (a) the accessibility of cognitive-affective mediating units (such as encodings, expectancies and beliefs, affects, and goals) and (b) the organization of relationships through which these units interact with each other and with psychological features of situations. The theory accounts for individual differences in predictable patterns of variability across situations (e.g., if A then she X, but if B then she Y), as well as for overall average levels of behavior, as essential expressions or behavioral signatures of the same underlying personality system. Situations, personality dispositions, dynamics, and structure were reconceptualized from this perspective.

Rotation invariants of vector fields from orthogonal moments

Czech Academy of Sciences Publication Activity Database

Yang, B.; Kostková, Jitka; Flusser, Jan; Suk, Tomáš; Bujack, R.

2018-01-01

Roč. 74, č. 1 (2018), s. 110-121 ISSN 0031-3203 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Vector field * Total rotation * Invariants * Gaussian–Hermite moments * Zernike moments * Numerical stability Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.582, year: 2016 http://library.utia.cas.cz/separaty/2017/ZOI/flusser-0478329.pdf

Scale invariant Volkov–Akulov supergravity

Energy Technology Data Exchange (ETDEWEB)

Ferrara, S., E-mail: sergio.ferrara@cern.ch [Th-Ph Department, CERN, CH-1211 Geneva 23 (Switzerland); INFN – Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044 Frascati (Italy); Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Porrati, M., E-mail: mp9@nyu.edu [Th-Ph Department, CERN, CH-1211 Geneva 23 (Switzerland); CCPP, Department of Physics, NYU, 4 Washington Pl., New York, NY 10003 (United States); Sagnotti, A., E-mail: sagnotti@sns.it [Th-Ph Department, CERN, CH-1211 Geneva 23 (Switzerland); Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, 56126 Pisa (Italy)

2015-10-07

A scale invariant goldstino theory coupled to supergravity is obtained as a standard supergravity dual of a rigidly scale-invariant higher-curvature supergravity with a nilpotent chiral scalar curvature. The bosonic part of this theory describes a massless scalaron and a massive axion in a de Sitter Universe.

On the invariance principle

Energy Technology Data Exchange (ETDEWEB)

Moller-Nielsen, Thomas [University of Oxford (United Kingdom)

2014-07-01

Physicists and philosophers have long claimed that the symmetries of our physical theories - roughly speaking, those transformations which map solutions of the theory into solutions - can provide us with genuine insight into what the world is really like. According to this 'Invariance Principle', only those quantities which are invariant under a theory's symmetries should be taken to be physically real, while those quantities which vary under its symmetries should not. Physicists and philosophers, however, are generally divided (or, indeed, silent) when it comes to explaining how such a principle is to be justified. In this paper, I spell out some of the problems inherent in other theorists' attempts to justify this principle, and sketch my own proposed general schema for explaining how - and when - the Invariance Principle can indeed be used as a legitimate tool of metaphysical inference.

A functional LMO invariant for Lagrangian cobordisms

DEFF Research Database (Denmark)

Cheptea, Dorin; Habiro, Kazuo; Massuyeau, Gwénaël

2008-01-01

Lagrangian cobordisms are three-dimensional compact oriented cobordisms between once-punctured surfaces, subject to some homological conditions. We extend the Le–Murakami–Ohtsuki invariant of homology three-spheres to a functor from the category of Lagrangian cobordisms to a certain category...... of Jacobi diagrams. We prove some properties of this functorial LMO invariant, including its universality among rational finite-type invariants of Lagrangian cobordisms. Finally, we apply the LMO functor to the study of homology cylinders from the point of view of their finite-type invariants....

Testing Measurement Invariance Using MIMIC: Likelihood Ratio Test with a Critical Value Adjustment

Science.gov (United States)

Kim, Eun Sook; Yoon, Myeongsun; Lee, Taehun

2012-01-01

Multiple-indicators multiple-causes (MIMIC) modeling is often used to test a latent group mean difference while assuming the equivalence of factor loadings and intercepts over groups. However, this study demonstrated that MIMIC was insensitive to the presence of factor loading noninvariance, which implies that factor loading invariance should be…

Continuous Integrated Invariant Inference, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed project will develop a new technique for invariant inference and embed this and other current invariant inference and checking techniques in an...

Test of charge conjugation invariance

International Nuclear Information System (INIS)

Nefkens, B.M.K.; Prakhov, S.; Gaardestig, A.; Clajus, M.; Marusic, A.; McDonald, S.; Phaisangittisakul, N.; Price, J.W.; Starostin, A.; Tippens, W.B.; Allgower, C.E.; Spinka, H.; Bekrenev, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Briscoe, W.J.; Shafi, A.; Comfort, J.R.

2005-01-01

We report on the first determination of upper limits on the branching ratio (BR) of η decay to π 0 π 0 γ and to π 0 π 0 π 0 γ. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(η→π 0 π 0 γ) -4 at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(η→π 0 π 0 π 0 γ) -5 at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions

The Tripod School Climate Index: An Invariant Measure of School Safety and Relationships.

Science.gov (United States)

Phillips, Sarah Fierberg; Rowley, Jacob F S

2016-03-01

Recently revised standards for social work practice in schools encourage data-informed school climate interventions that implicitly require invariant measures of school climate. Invariant measures have the same meaning, scale, and origin across different groups of respondents. Although noninvariant measures bias statistical analyses and can lead users to erroneous conclusions, most school climate measures have not been tested for invariance. This study examines the invariance of the Tripod School Climate Index. Exploratory, confirmatory, and multiple-group confirmatory factor analyses were conducted on data collected from 66,531 students across 222 schools. Results indicate that the index is an excellent fit for the data and invariant by student grade level, demographic background, prior achievement, and dropout risk. Results imply that student responses can be validly aggregated to create school-level scores. The index will not bias studies of school climate interventions or bivariate analyses comparing perceptions of school climate across subgroups of students attending the same school. Given the centrality of school climate interventions to social work practice in schools and the consequences of noninvariance, the development of an index with these properties is an important contribution to the field.

Testing measurement invariance of the Learning Programme Management and Evaluation scale across academic achievement

Directory of Open Access Journals (Sweden)

Maelekanyo C. Mulaudzi

2016-10-01

Full Text Available Orientation: Measurement invariance is one of the most precarious aspects of the scale development process without which the interpretation of research findings on population subgroups may be ambiguous and even invalid. Besides tests for validity and reliability, measurement invariance represents the hallmark for psychometric compliance of a new measuring instrument and provides the basis for inference of research findings across a range of relevant population sub-groups. Research purpose: This study tested the measurement invariance of a Learning Programme Management and Evaluation (LPME scale across levels of academic achievement. Motivation for the study: It is important for any researcher involved in new scale development to ensure that the measurement instrument and its underlying constructs have proper structural alignment and that they both have the same level of meaning and significance across comparable heterogeneous groups. Research design, approach and method: A quantitative, non-experimental, cross-sectional survey design was used, and data were obtained from 369 participants who were selected from three public sector organisations using a probabilistic simple random sampling technique. The Statistical Package for Social Sciences and Analysis of Moment Structures software (versions 21.0.0 were used to analyse the data. Main findings: The findings show that all the four invariance models tested have achieved acceptable goodness-of-fit indices. Furthermore, the findings show that the factorial structure of the LPME scale and the meaning of its underlying constructs are invariant across different levels of academic achievement for human resource development (HRD practitioners and learners or apprentices involved in occupational learning programmes. Practical implications: The findings of this study suggest practical implications for HRD scholars as they are enabled to make informed decisional balance comparisons involving educational

Psychometric evaluation and sex invariance of the Spanish version of the Body and Appearance Self-Conscious Emotions Scale.

Science.gov (United States)

Alcaraz-Ibáñez, Manuel; Sicilia, Alvaro

2018-06-01

This study examined the psychometric properties of a Spanish translation of the Body and Appearance Self-Conscious Emotions Scale (BASES; Castonguay et al., 2014) in a sample of university Spanish students. A total of 815 participants enrolled in two public universities located in Almería and Elche, Spain, completed the BASES along with measures of social physique anxiety and positive/negative affect. Exploratory and confirmatory factor analyses showed that one item failed to load clearly on the hypothesized factor (guilt). Once it was removed, results supported the hypothesized four-factor structure. Evidence of invariance of the four-factor structure across sex was obtained. Scores on the BASES showed adequate internal consistency and acceptable convergent validity. Compared to men, women reported significantly higher body and appearance-related guilt and shame, and significant lower authentic and hubristic pride. Preliminary evidence supporting the validity and reliability of the Spanish translation of the BASES is provided. Copyright © 2018 Elsevier Ltd. All rights reserved.

Scale invariant Volkov–Akulov supergravity

Directory of Open Access Journals (Sweden)

S. Ferrara

2015-10-01

Full Text Available A scale invariant goldstino theory coupled to supergravity is obtained as a standard supergravity dual of a rigidly scale-invariant higher-curvature supergravity with a nilpotent chiral scalar curvature. The bosonic part of this theory describes a massless scalaron and a massive axion in a de Sitter Universe.

Measurement invariance of the Emotion Regulation Questionnaire (ERQ) : A cross-national validity study

NARCIS (Netherlands)

Sala, M.N.; Molina, P.; Abler, B.; Kessler, H.; Vanbrabant, L.G.F.|info:eu-repo/dai/nl/355587327; Van de Schoot, R.|info:eu-repo/dai/nl/304833207

2012-01-01

The goal of this research was to examine the measurement invariance of the Emotion Regulation Questionnaire (ERQ; Gross & John, 2003) across two European nations. Participants were Italian and German undergraduate students. First, confirmatory factor analysis was used to test for the two-factor

Charge conjugation invariance of the spectator equations

International Nuclear Information System (INIS)

Gross, F.

1999-01-01

In response to recent criticism, the authors show how to define the spectator equations for negative energies so that charge conjugation invariance is preserved. The result, which emerges naturally from the application of spectator principles to systems of particles with negative energies, is to replace all factors of the external energies W iota by √ W 2 iota , insuring that the amplitudes are independent of the sign of the energies W iota

Generalized operator canonical formalism and gauge invariance

International Nuclear Information System (INIS)

Fradkina, T.E.

1988-01-01

A direct proof is given in the functional representation of the invariance of the S-matrix constructed in the framework of the generalized operator canonical formalism. We find the traditional functional expression for the S-matrix (without point-splitting in the time factor) in the generalized phase space, as well as in the ghost configuration space. An explicit expression is obtained for the effective unitarizing Hamiltonian for gauge theories with constraints of arbitrary rank

Structure of four executive functioning tests in healthy older adults.

Science.gov (United States)

de Frias, Cindy M; Dixon, Roger A; Strauss, Esther

2006-03-01

The authors examined the factor structure of 4 indicators of executive functioning derived from 2 new (i.e., Hayling and Brixton) and 2 traditional (i.e., Stroop and Color Trails) tests. Data were from a cross-sectional sample of 55- to 85-year-old healthy adults (N=427) from the Victoria Longitudinal Study. Confirmatory factor analysis (LISREL 8.52) tested both a 2-factor model of Inhibition (Hayling, Stroop) and Shifting (Brixton, Color Trails) and a single-factor model. The 2-factor model did not fit the data because the covariance matrix of the factors was not positive definite. The single-factor model fit the data well, chi(2)(2, N=427)=0.32, p=.85, root-mean-square error of approximation (RMSEA)=.00, comparative fit index (CFI)=1.00, goodness-of-fit index (GFI)=1.00. Moreover, the single-factor structure of executive functioning was invariant (configural and metric) across gender, and invariant (configural with limited metric) across age. Structural relations showed that poorer executive functioning performance was related to older age and lower fluid intelligence, chi(2)(11, N=418)=23.04, p=.02, RMSEA=.05, CFI=.97, GFI=.98.

Can Parental Bonding Be Assessed in Children? Factor Structure and Factorial Invariance of the Parental Bonding Instrument (PBI) between Adults and Children

Science.gov (United States)

Tsaousis, Ioannis; Mascha, Katerina; Giovazolias, Theodoros

2012-01-01

This study examined the factorial structure of the Parental Bonding Instrument (PBI) in the Greek population. Using confirmatory factor analysis different proposed models of the basic dimensions of PBI were evaluated. The results indicated that Kendler's three-factor (i.e. care, protectiveness and authoritarianism) solution was found to be more…

Computation of partially invariant solutions for the Einstein Walker manifolds' identifying equations

Science.gov (United States)

Nadjafikhah, Mehdi; Jafari, Mehdi

2013-12-01

In this paper, partially invariant solutions (PISs) method is applied in order to obtain new four-dimensional Einstein Walker manifolds. This method is based on subgroup classification for the symmetry group of partial differential equations (PDEs) and can be regarded as the generalization of the similarity reduction method. For this purpose, those cases of PISs which have the defect structure δ=1 and are resulted from two-dimensional subalgebras are considered in the present paper. Also it is shown that the obtained PISs are distinct from the invariant solutions that obtained by similarity reduction method.

Factor structure and psychometric properties of the Anxiety Sensitivity Index-3 in an Italian community sample

Directory of Open Access Journals (Sweden)

Marta eGhisi

2016-02-01

Full Text Available Anxiety Sensitivity (AS is defined as the fear of anxiety and of arousal-related bodily sensations, arising from erroneous beliefs that these sensations will have adverse consequences. AS plays a key role both in the onset and in the maintenance of several disorders, particularly anxiety disorders. To date, only two studies on American samples have examined the bifactor structure of the Anxiety Sensitivity Index-3 (ASI-3; therefore, findings on different cultures are needed. The main purpose of the present study was to assess the factor structure and psychometric properties of the ASI-3 in an Italian community sample. Participants were recruited from the general population (N=1507. The results of a series of confirmatory factor analyses indicated that the bifactor structure fitted the data better than the most commonly accepted structure for the measure and that it was invariant across gender. Moreover, the current study provided evidence regarding the ASI-3’s reliability and its convergent and divergent validity. Lastly, results pertaining incremental validity of the ASI-3 Physical and Cognitive Concerns subscales above and beyond the total showed that the former was not associated with a measure of physiological anxiety, whereas the latter was weakly associated with a measure of worry.Findings suggest that the ASI-3 is comprised of a dominant general factor and three specific independent factors; given the dominance of the general factor, the use of the ASI-3 total score as a measure of the general fear of anxiety is recommended in both clinical and research settings.

Multidimensional Inventory of Hypochondriacal Traits: An Examination of a Bifactor Model and Measurement Invariance Between Those With and Without a Self-Reported Medical Condition.

Science.gov (United States)

Bardeen, Joseph R; Fergus, Thomas A

2017-08-01

The Multidimensional Inventory of Hypochondriacal Traits (MIHT) is a self-report measure that assesses four interrelated domains of health anxiety (i.e., Cognitive, Behavioral, Perceptual, Affective). Prior research has supported a correlated four-factor model, as well as a hierarchical model, in which each of the four factors load onto the higher order health anxiety construct. However, a bifactor modeling approach has yet to be used to examine the factor structure of the MIHT. Results supported a bifactor model of the MIHT in three different samples (i.e., unselected based on current medical status [ n = 824], and those with [ n = 348] and without [ n = 354] a self-reported medical condition). The MIHT appears to be strongly multidimensional, with three of the four subscales providing substantive value. Confirmatory factor analysis supported the configural and metric/scalar invariance of the bifactor model between those with and without a self-reported medical condition. Results provide support for a bifactor conceptualization of the MIHT and the invariance of that model across levels of current health status.

Exposing region duplication through local geometrical color invariant features

Science.gov (United States)

Gong, Jiachang; Guo, Jichang

2015-05-01

Many advanced image-processing softwares are available for tampering images. How to determine the authenticity of an image has become an urgent problem. Copy-move is one of the most common image forgery operations. Many methods have been proposed for copy-move forgery detection (CMFD). However, most of these methods are designed for grayscale images without any color information used. They are usually not suitable when the duplicated regions have little structure or have undergone various transforms. We propose a CMFD method using local geometrical color invariant features to detect duplicated regions. The method starts by calculating the color gradient of the inspected image. Then, we directly take the color gradient as the input for scale invariant features transform (SIFT) to extract color-SIFT descriptors. Finally, keypoints are matched and clustered before their geometrical relationship is estimated to expose the duplicated regions. We evaluate the detection performance and computational complexity of the proposed method together with several popular CMFD methods on a public database. Experimental results demonstrate the efficacy of the proposed method in detecting duplicated regions with various transforms and poor structure.

Recent progress in invariant pattern recognition

Science.gov (United States)

Arsenault, Henri H.; Chang, S.; Gagne, Philippe; Gualdron Gonzalez, Oscar

1996-12-01

We present some recent results in invariant pattern recognition, including methods that are invariant under two or more distortions of position, orientation and scale. There are now a few methods that yield good results under changes of both rotation and scale. Some new methods are introduced. These include locally adaptive nonlinear matched filters, scale-adapted wavelet transforms and invariant filters for disjoint noise. Methods using neural networks will also be discussed, including an optical method that allows simultaneous classification of multiple targets.

Precision tests of CPT invariance with single trapped antiprotons

Energy Technology Data Exchange (ETDEWEB)

Ulmer, Stefan [RIKEN, Ulmer Initiative Research Unit, Wako, Saitama (Japan); Collaboration: BASE-Collaboration

2015-07-01

The reason for the striking imbalance of matter and antimatter in our Universe has yet to be understood. This is the motivation and inspiration to conduct high precision experiments comparing the fundamental properties of matter and antimatter equivalents at lowest energies and with greatest precision. According to theory, the most sensitive tests of CPT invariance are measurements of antihydrogen ground-state hyperfine splitting as well as comparisons of proton and antiproton magnetic moments. Within the BASE collaboration we target the latter. By using a double Penning trap we performed very recently the first direct high precision measurement of the proton magnetic moment. The achieved fractional precision of 3.3 ppb improves the currently accepted literature value by a factor of 2.5. Application of the method to a single trapped antiproton will improve precision of the particles magnetic moment by more than a factor of 1000, thus providing one of the most stringent tests of CPT invariance. In my talk I report on the status and future perspectives of our efforts.

Factorial Structure and Age-Related Psychometrics of the MIDUS Personality Adjective Items across the Lifespan

Science.gov (United States)

Zimprich, Daniel; Allemand, Mathias; Lachman, Margie E.

2014-01-01

The present study addresses issues of measurement invariance and comparability of factor parameters of Big Five personality adjective items across age. Data from the Midlife in the United States (MIDUS) survey were used to investigate age-related developmental psychometrics of the MIDUS personality adjective items in two large cross-sectional samples (exploratory sample: N = 862; analysis sample: N = 3,000). After having established and replicated a comprehensive five-factor structure of the measure, increasing levels of measurement invariance were tested across ten age groups. Results indicate that the measure demonstrates strict measurement invariance in terms of number of factors and factor loadings. Also, we found that factor variances and covariances were equal across age groups. By contrast, a number of age-related factor mean differences emerged. The practical implications of these results are discussed and future research is suggested. PMID:21910548

Finite type invariants and fatgraphs

DEFF Research Database (Denmark)

Andersen, Jørgen Ellegaard; Bene, Alex; Meilhan, Jean-Baptiste Odet Thierry

2010-01-01

–Murakami–Ohtsuki of the link invariant of Andersen–Mattes–Reshetikhin computed relative to choices determined by the fatgraph G; this provides a basic connection between 2d geometry and 3d quantum topology. For each fixed G, this invariant is shown to be universal for homology cylinders, i.e., G establishes an isomorphism...

Ermakov–Lewis invariants and Reid systems

Energy Technology Data Exchange (ETDEWEB)

Mancas, Stefan C., E-mail: stefan.mancas@erau.edu [Department of Mathematics, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICyT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico)

2014-06-13

Reid's mth-order generalized Ermakov systems of nonlinear coupling constant α are equivalent to an integrable Emden–Fowler equation. The standard Ermakov–Lewis invariant is discussed from this perspective, and a closed formula for the invariant is obtained for the higher-order Reid systems (m≥3). We also discuss the parametric solutions of these systems of equations through the integration of the Emden–Fowler equation and present an example of a dynamical system for which the invariant is equivalent to the total energy. - Highlights: • Reid systems of order m are connected to Emden–Fowler equations. • General expressions for the Ermakov–Lewis invariants both for m=2 and m≥3 are obtained. • Parametric solutions of the Emden–Fowler equations related to Reid systems are obtained.

Scoring correction for MMPI-2 Hs scale with patients experiencing a traumatic brain injury: a test of measurement invariance.

Science.gov (United States)

Alkemade, Nathan; Bowden, Stephen C; Salzman, Louis

2015-02-01

It has been suggested that MMPI-2 scoring requires removal of some items when assessing patients after a traumatic brain injury (TBI). Gass (1991. MMPI-2 interpretation and closed head injury: A correction factor. Psychological assessment, 3, 27-31) proposed a correction procedure in line with the hypothesis that MMPI-2 endorsement may be affected by symptoms of TBI. This study assessed the validity of the Gass correction procedure. A sample of patients with a TBI (n = 242), and a random subset of the MMPI-2 normative sample (n = 1,786). The correction procedure implies a failure of measurement invariance across populations. This study examined measurement invariance of one of the MMPI-2 scales (Hs) that includes TBI correction items. A four-factor model of the MMPI-2 Hs items was defined. The factor model was found to meet the criteria for partial measurement invariance. Analysis of the change in sensitivity and specificity values implied by partial measurement invariance failed to indicate significant practical impact of partial invariance. Overall, the results support continued use of all Hs items to assess psychological well-being in patients with TBI. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Noise-invariant Neurons in the Avian Auditory Cortex: Hearing the Song in Noise

Science.gov (United States)

Moore, R. Channing; Lee, Tyler; Theunissen, Frédéric E.

2013-01-01

Given the extraordinary ability of humans and animals to recognize communication signals over a background of noise, describing noise invariant neural responses is critical not only to pinpoint the brain regions that are mediating our robust perceptions but also to understand the neural computations that are performing these tasks and the underlying circuitry. Although invariant neural responses, such as rotation-invariant face cells, are well described in the visual system, high-level auditory neurons that can represent the same behaviorally relevant signal in a range of listening conditions have yet to be discovered. Here we found neurons in a secondary area of the avian auditory cortex that exhibit noise-invariant responses in the sense that they responded with similar spike patterns to song stimuli presented in silence and over a background of naturalistic noise. By characterizing the neurons' tuning in terms of their responses to modulations in the temporal and spectral envelope of the sound, we then show that noise invariance is partly achieved by selectively responding to long sounds with sharp spectral structure. Finally, to demonstrate that such computations could explain noise invariance, we designed a biologically inspired noise-filtering algorithm that can be used to separate song or speech from noise. This novel noise-filtering method performs as well as other state-of-the-art de-noising algorithms and could be used in clinical or consumer oriented applications. Our biologically inspired model also shows how high-level noise-invariant responses could be created from neural responses typically found in primary auditory cortex. PMID:23505354

Noise-invariant neurons in the avian auditory cortex: hearing the song in noise.

Science.gov (United States)

Moore, R Channing; Lee, Tyler; Theunissen, Frédéric E

2013-01-01

Given the extraordinary ability of humans and animals to recognize communication signals over a background of noise, describing noise invariant neural responses is critical not only to pinpoint the brain regions that are mediating our robust perceptions but also to understand the neural computations that are performing these tasks and the underlying circuitry. Although invariant neural responses, such as rotation-invariant face cells, are well described in the visual system, high-level auditory neurons that can represent the same behaviorally relevant signal in a range of listening conditions have yet to be discovered. Here we found neurons in a secondary area of the avian auditory cortex that exhibit noise-invariant responses in the sense that they responded with similar spike patterns to song stimuli presented in silence and over a background of naturalistic noise. By characterizing the neurons' tuning in terms of their responses to modulations in the temporal and spectral envelope of the sound, we then show that noise invariance is partly achieved by selectively responding to long sounds with sharp spectral structure. Finally, to demonstrate that such computations could explain noise invariance, we designed a biologically inspired noise-filtering algorithm that can be used to separate song or speech from noise. This novel noise-filtering method performs as well as other state-of-the-art de-noising algorithms and could be used in clinical or consumer oriented applications. Our biologically inspired model also shows how high-level noise-invariant responses could be created from neural responses typically found in primary auditory cortex.

Noise-invariant neurons in the avian auditory cortex: hearing the song in noise.

Directory of Open Access Journals (Sweden)

R Channing Moore

Full Text Available Given the extraordinary ability of humans and animals to recognize communication signals over a background of noise, describing noise invariant neural responses is critical not only to pinpoint the brain regions that are mediating our robust perceptions but also to understand the neural computations that are performing these tasks and the underlying circuitry. Although invariant neural responses, such as rotation-invariant face cells, are well described in the visual system, high-level auditory neurons that can represent the same behaviorally relevant signal in a range of listening conditions have yet to be discovered. Here we found neurons in a secondary area of the avian auditory cortex that exhibit noise-invariant responses in the sense that they responded with similar spike patterns to song stimuli presented in silence and over a background of naturalistic noise. By characterizing the neurons' tuning in terms of their responses to modulations in the temporal and spectral envelope of the sound, we then show that noise invariance is partly achieved by selectively responding to long sounds with sharp spectral structure. Finally, to demonstrate that such computations could explain noise invariance, we designed a biologically inspired noise-filtering algorithm that can be used to separate song or speech from noise. This novel noise-filtering method performs as well as other state-of-the-art de-noising algorithms and could be used in clinical or consumer oriented applications. Our biologically inspired model also shows how high-level noise-invariant responses could be created from neural responses typically found in primary auditory cortex.

Conformal invariance in the long-range Ising model

Directory of Open Access Journals (Sweden)

Miguel F. Paulos

2016-01-01

Full Text Available We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.

Conformal Invariance in the Long-Range Ising Model

CERN Document Server

Paulos, Miguel F; van Rees, Balt C; Zan, Bernardo

2016-01-01

We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.

Conformal invariance in the long-range Ising model

Energy Technology Data Exchange (ETDEWEB)

Paulos, Miguel F. [CERN, Theory Group, Geneva (Switzerland); Rychkov, Slava, E-mail: slava.rychkov@lpt.ens.fr [CERN, Theory Group, Geneva (Switzerland); Laboratoire de Physique Théorique de l' École Normale Supérieure (LPTENS), Paris (France); Faculté de Physique, Université Pierre et Marie Curie (UPMC), Paris (France); Rees, Balt C. van [CERN, Theory Group, Geneva (Switzerland); Zan, Bernardo [Institute of Physics, Universiteit van Amsterdam, Amsterdam (Netherlands)

2016-01-15

We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.

BRDF invariant stereo using light transport constancy.

Science.gov (United States)

Wang, Liang; Yang, Ruigang; Davis, James E

2007-09-01

Nearly all existing methods for stereo reconstruction assume that scene reflectance is Lambertian and make use of brightness constancy as a matching invariant. We introduce a new invariant for stereo reconstruction called light transport constancy (LTC), which allows completely arbitrary scene reflectance (bidirectional reflectance distribution functions (BRDFs)). This invariant can be used to formulate a rank constraint on multiview stereo matching when the scene is observed by several lighting configurations in which only the lighting intensity varies. In addition, we show that this multiview constraint can be used with as few as two cameras and two lighting configurations. Unlike previous methods for BRDF invariant stereo, LTC does not require precisely configured or calibrated light sources or calibration objects in the scene. Importantly, the new constraint can be used to provide BRDF invariance to any existing stereo method whenever appropriate lighting variation is available.

Variance composition, measurement invariance by gender, and construct validity of the Femininity Ideology Scale-Short Form.

Science.gov (United States)

Levant, Ronald F; Alto, Kathleen M; McKelvey, Daniel K; Richmond, Katherine A; McDermott, Ryon C

2017-11-01

The current study extended prior work on the Femininity Ideology Scale (FIS), a multidimensional measure of traditional femininity ideology (TFI), in several ways. First, we conducted exploratory factor and bifactor analyses, which revealed a general TFI factor and 3 specific factors: dependence/deference, purity, and emotionality/traditional roles. Second, based on these results we developed the 12-item FIS-Short Form (FIS-SF). Third, we assessed the FIS-SF using confirmatory factor analysis on a separate sample, finding that the items loaded on the general factor and 3 specific factors as hypothesized, and that the bifactor model fit better than common factors and unidimensional models. Fourth, model-based reliability estimates tentatively support the use of raw scores to represent the general TFI factor and the emotionality/traditional roles specific factor, but the other 2 specific factors are best measured using SEM or by ipsatizing their scores. Fifth, we assessed measurement invariance across 2 gender groups, finding evidence for configural invariance for all factors, and for partial metric invariance for the specific factors. Sixth, we found evidence for the convergent construct validity of the FIS-SF general factor and the emotionality/traditional roles specific factors by examining relationships with the latent variables of several constructs in the nomological network. The results are discussed in relationship to prior literature, future research directions, applications to counseling practice, and limitations. Data (N = 1,472, 907 women, 565 men, 530 people of color) were from community and college participants who responded to an online survey. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Metric invariance in object recognition: a review and further evidence.

Science.gov (United States)

Cooper, E E; Biederman, I; Hummel, J E

1992-06-01

Phenomenologically, human shape recognition appears to be invariant with changes of orientation in depth (up to parts occlusion), position in the visual field, and size. Recent versions of template theories (e.g., Ullman, 1989; Lowe, 1987) assume that these invariances are achieved through the application of transformations such as rotation, translation, and scaling of the image so that it can be matched metrically to a stored template. Presumably, such transformations would require time for their execution. We describe recent priming experiments in which the effects of a prior brief presentation of an image on its subsequent recognition are assessed. The results of these experiments indicate that the invariance is complete: The magnitude of visual priming (as distinct from name or basic level concept priming) is not affected by a change in position, size, orientation in depth, or the particular lines and vertices present in the image, as long as representations of the same components can be activated. An implemented seven layer neural network model (Hummel & Biederman, 1992) that captures these fundamental properties of human object recognition is described. Given a line drawing of an object, the model activates a viewpoint-invariant structural description of the object, specifying its parts and their interrelations. Visual priming is interpreted as a change in the connection weights for the activation of: a) cells, termed geon feature assemblies (GFAs), that conjoin the output of units that represent invariant, independent properties of a single geon and its relations (such as its type, aspect ratio, relations to other geons), or b) a change in the connection weights by which several GFAs activate a cell representing an object.

Construction of time-dependent dynamical invariants: A new approach

International Nuclear Information System (INIS)

Bertin, M. C.; Pimentel, B. M.; Ramirez, J. A.

2012-01-01

We propose a new way to obtain polynomial dynamical invariants of the classical and quantum time-dependent harmonic oscillator from the equations of motion. We also establish relations between linear and quadratic invariants, and discuss how the quadratic invariant can be related to the Ermakov invariant.

Wavelet-based moment invariants for pattern recognition

Science.gov (United States)

Chen, Guangyi; Xie, Wenfang

2011-07-01

Moment invariants have received a lot of attention as features for identification and inspection of two-dimensional shapes. In this paper, two sets of novel moments are proposed by using the auto-correlation of wavelet functions and the dual-tree complex wavelet functions. It is well known that the wavelet transform lacks the property of shift invariance. A little shift in the input signal will cause very different output wavelet coefficients. The autocorrelation of wavelet functions and the dual-tree complex wavelet functions, on the other hand, are shift-invariant, which is very important in pattern recognition. Rotation invariance is the major concern in this paper, while translation invariance and scale invariance can be achieved by standard normalization techniques. The Gaussian white noise is added to the noise-free images and the noise levels vary with different signal-to-noise ratios. Experimental results conducted in this paper show that the proposed wavelet-based moments outperform Zernike's moments and the Fourier-wavelet descriptor for pattern recognition under different rotation angles and different noise levels. It can be seen that the proposed wavelet-based moments can do an excellent job even when the noise levels are very high.

Rosenberg Self-Esteem Scale: Method Effects, Factorial Structure and Scale Invariance Across Migrant Child and Urban Child Populations in China.

Science.gov (United States)

Wu, Yang; Zuo, Bin; Wen, Fangfang; Yan, Lei

2017-01-01

Using confirmatory factor analyses, this study examined the method effects on a Chinese version of the Rosenberg Self-Esteem Scale (RSES; Rosenberg, 1965 ) in a sample of migrant and urban children in China. In all, 982 children completed the RSES, and 9 models and 9 corresponding variants were specified and tested. The results indicated that the method effects are associated with both positively and negatively worded items and that Item 8 should be treated as a positively worded item. Additionally, the method effects models were invariant across migrant and urban children in China.

Frozen reaction fronts in steady flows: A burning-invariant-manifold perspective

Science.gov (United States)

Mahoney, John R.; Li, John; Boyer, Carleen; Solomon, Tom; Mitchell, Kevin A.

2015-12-01

The dynamics of fronts, such as chemical reaction fronts, propagating in two-dimensional fluid flows can be remarkably rich and varied. For time-invariant flows, the front dynamics may simplify, settling in to a steady state in which the reacted domain is static, and the front appears "frozen." Our central result is that these frozen fronts in the two-dimensional fluid are composed of segments of burning invariant manifolds, invariant manifolds of front-element dynamics in x y θ space, where θ is the front orientation. Burning invariant manifolds (BIMs) have been identified previously as important local barriers to front propagation in fluid flows. The relevance of BIMs for frozen fronts rests in their ability, under appropriate conditions, to form global barriers, separating reacted domains from nonreacted domains for all time. The second main result of this paper is an understanding of bifurcations that lead from a nonfrozen state to a frozen state, as well as bifurcations that change the topological structure of the frozen front. Although the primary results of this study apply to general fluid flows, our analysis focuses on a chain of vortices in a channel flow with an imposed wind. For this system, we present both experimental and numerical studies that support the theoretical analysis developed here.

Novel topological invariants and anomalies

International Nuclear Information System (INIS)

Hirayama, M.; Sugimasa, N.

1987-01-01

It is shown that novel topological invariants are associated with a class of Dirac operators. Trace formulas which are similar to but different from Callias's formula are derived. Implications of these topological invariants to anomalies in quantum field theory are discussed. A new class of anomalies are calculated for two models: one is two dimensional and the other four dimensional

Wilson loop invariants from WN conformal blocks

Directory of Open Access Journals (Sweden)

Oleg Alekseev

2015-12-01

Full Text Available Knot and link polynomials are topological invariants calculated from the expectation value of loop operators in topological field theories. In 3D Chern–Simons theory, these invariants can be found from crossing and braiding matrices of four-point conformal blocks of the boundary 2D CFT. We calculate crossing and braiding matrices for WN conformal blocks with one component in the fundamental representation and another component in a rectangular representation of SU(N, which can be used to obtain HOMFLY knot and link invariants for these cases. We also discuss how our approach can be generalized to invariants in higher-representations of WN algebra.

Invariants of triangular Lie algebras

International Nuclear Information System (INIS)

Boyko, Vyacheslav; Patera, Jiri; Popovych, Roman

2007-01-01

Triangular Lie algebras are the Lie algebras which can be faithfully represented by triangular matrices of any finite size over the real/complex number field. In the paper invariants ('generalized Casimir operators') are found for three classes of Lie algebras, namely those which are either strictly or non-strictly triangular, and for so-called special upper triangular Lie algebras. Algebraic algorithm of Boyko et al (2006 J. Phys. A: Math. Gen.39 5749 (Preprint math-ph/0602046)), developed further in Boyko et al (2007 J. Phys. A: Math. Theor.40 113 (Preprint math-ph/0606045)), is used to determine the invariants. A conjecture of Tremblay and Winternitz (2001 J. Phys. A: Math. Gen.34 9085), concerning the number of independent invariants and their form, is corroborated

Local topology via the invariants of the velocity gradient tensor within vortex clusters and intense Reynolds stress structures in turbulent channel flow

International Nuclear Information System (INIS)

Buchner, Abel-John; Kitsios, Vassili; Atkinson, Callum; Soria, Julio; Lozano-Durán, Adrián

2016-01-01

Previous works have shown that momentum transfer in the wall–normal direction within turbulent wall–bounded flows occurs primarily within coherent structures defined by regions of intense Reynolds stress [1]. Such structures may be classified into wall–attached and wall–detached structures with the latter being typically weak, small–scale, and isotropically oriented, while the former are larger and carry most of the Reynolds stresses. The mean velocity fluctuation within each structure may also be used to separate structures by their dynamic properties. This study aims to extract information regarding the scales, kinematics and dynamics of these structures within the topological framework of the invariants of the velocity gradient tensor (VGT). The local topological characteristics of these intense Reynolds stress structures are compared to the topological characteristics of vortex clusters defined by the discriminant of the velocity gradient tensor. The alignment of vorticity with the principal strain directions within these structures is also determined, and the implications of these findings are discussed. (paper)

On the algebra of local unitary invariants of pure and mixed quantum states

International Nuclear Information System (INIS)

Vrana, Peter

2011-01-01

We study the structure of the inverse limit of the graded algebras of local unitary invariant polynomials using its Hilbert series. For k subsystems, we show that the inverse limit is a free algebra and the number of algebraically independent generators with homogenous degree 2m equals the number of conjugacy classes of index m subgroups in a free group on k - 1 generators. Similarly, we show that the inverse limit in the case of k-partite mixed state invariants is free and the number of algebraically independent generators with homogenous degree m equals the number of conjugacy classes of index m subgroups in a free group on k generators. The two statements are shown to be equivalent. To illustrate the equivalence, using the representation theory of the unitary groups, we obtain all invariants in the m = 2 graded parts and express them in a simple form both in the case of mixed and pure states. The transformation between the two forms is also derived. Analogous invariants of higher degree are also introduced.

Action priors for learning domain invariances

CSIR Research Space (South Africa)

Rosman, Benjamin S

2015-04-01

Full Text Available behavioural invariances in the domain, by identifying actions to be prioritised in local contexts, invariant to task details. This information has the effect of greatly increasing the speed of solving new problems. We formalise this notion as action priors...

Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines

International Nuclear Information System (INIS)

Cherednikov, Igor O.

2017-01-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.

Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines

Energy Technology Data Exchange (ETDEWEB)

Cherednikov, Igor O. [Antwerpen Univ. (Belgium). Dept. Fysica; Veken, Frederik F. van der [CERN, Geneva (Switzerland)

2017-05-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.

Formal structures, the concepts of covariance, invariance, equivalent reference frames, and the principle Relativity

Science.gov (United States)

Rodrigues, W. A.; Scanavini, M. E. F.; de Alcantara, L. P.

1990-02-01

In this paper a given spacetime theory T is characterized as the theory of a certain species of structure in the sense of Bourbaki [1]. It is then possible to clarify in a rigorous way the concepts of passive and active covariance of T under the action of the manifold mapping group G M . For each T, we define also an invariance group G I T and, in general, G I T ≠ G M . This group is defined once we realize that, for each τ ∈ ModT, each explicit geometrical object defining the structure can be classified as absolute or dynamical [2]. All spacetime theories possess also implicit geometrical objects that do not appear explicitly in the structure. These implicit objects are not absolute nor dynamical. Among them there are the reference frame fields, i.e., “timelike” vector fields X ∈ TU,U subseteq M M, where M is a manifold which is part of ST, a substructure for each τ ∈ ModT, called spacetime. We give a physically motivated definition of equivalent reference frames and introduce the concept of the equivalence group of a class of reference frames of kind X according to T, G X T. We define that T admits a weak principle of relativity (WPR) only if G X T ≠ identity for some X. If G X T = G I T for some X, we say that T admits a strong principle of relativity (PR). The results of this paper generalize and clarify several results obtained by Anderson [2], Scheibe [3], Hiskes [4], Recami and Rodrigues [5], Friedman [6], Fock [7], and Scanavini [8]. Among the novelties here, there is the realization that the definitions of G I T and G X T can be given only when certain boundary conditions for the equations of motion of T can be physically realizable in the domain U U subseteq M M, where a given reference frame is defined. The existence of physically realizable boundary conditions for each τ ∈ ModT (in ∂ U), in contrast with the mathematically possible boundary condition, is then seen to be essential for the validity of a principle of relativity for T

(Invariability in the Samoan syntax/prosody interface and consequences for syntactic parsing

Directory of Open Access Journals (Sweden)

Kristine M. Yu

2017-10-01

Full Text Available While it has long been clear that prosody should be part of the grammar influencing the action of the syntactic parser, how to bring prosody into computational models of syntactic parsing has remained unclear. The challenge is that prosodic information in the speech signal is the result of the interaction of a multitude of conditioning factors. From this output, how can we factor out the contribution of syntax to conditioning prosodic events? And if we are able to do that factorization and define a production model from the syntactic grammar to a prosodified utterance, how can we then define a comprehension model based on that production model? In this case study of the Samoan morphosyntax-prosody interface, we show how to factor out the influence of syntax on prosody in empirical work and confirm there is invariable morphosyntactic conditioning of high edge tones. Then, we show how this invariability can be precisely characterized and used by a parsing model that factors the various influences of morphosyntax on tonal events. We expect that models of these kinds can be extended to more comprehensive perspectives on Samoan and to languages where the syntax/prosody coupling is more complex.

Gauge-invariant formulation of SU(2) gluodynamics

International Nuclear Information System (INIS)

Simonov, Yu.A.

1984-01-01

The internal structure of a double asymmetric rotator is revealed in vector potential Asub(μa) via a proposed polar representation (PR). In the functional integral a natural gauge choice exists in PR not accompanied by Faddeev-Popov ghosts and Gribov ambiguities. Classical equations in PR are written in terms of only gauge invariant quantities. Instantons and magnetic monopoles in the Bogolmolny-Prasad-Sommerfield limit as well as the color-magnetic field of the 'tHooft-Polyakov monopole are studied in PR

Observation of structure in invariant-mass distributions from ν and antiν interactions

International Nuclear Information System (INIS)

Benvenuti, A.; Cline, D.; Ford, W.T.; Imlay, R.; Ling, T.Y.; Mann, A.K.; Reeder, D.D.; Rubbia, C.; Stefanski, R.; Sulak, L.; Wanderer, P.

1976-01-01

New data on the inelastic scattering of ν and antiν by nucleons show a significant excess of antiν events at large invariant mass (W), reflecting the high-y anomaly and an enhancement in ν scattering centered at W=2.2 +- 0.3 GeV with properties consistent with the production of new baryon states

Quantum field theoretic properties of nonabelian phase factors

International Nuclear Information System (INIS)

Wieczorek, E.

1984-01-01

The paper is concerned with quantum field theoretical properies of nonabelian phase factors. The phase factors defining parallel transport in fiber bundle space are the necessary tool for the construction of gauge invariant nonlocal operators describing bound states in QCD. General structures of such operators are discussed and renormalization properties as well as relations between meson and baryon operators are obtained from a study of the underlying phase factors

On stabilisability of 2-D MIMO shift-invariant systems

Czech Academy of Sciences Publication Activity Database

Augusta, Petr; Augustová, Petra

2013-01-01

Roč. 350, č. 10 (2013), s. 2949-2966 ISSN 0016-0032 R&D Projects: GA ČR GPP103/12/P494 Institutional support: RVO:67985556 Keywords : spatially invariant system * stabilisation * multiple-input-multiple-output system, * positive polynomial Subject RIV: BC - Control Systems Theory Impact factor: 2.260, year: 2013 http://library.utia.cas.cz/separaty/2013/TR/augusta-0398772.pdf

Invariant measures for stochastic nonlinear beam and wave equations

Czech Academy of Sciences Publication Activity Database

Brzezniak, Z.; Ondreját, Martin; Seidler, Jan

2016-01-01

Roč. 260, č. 5 (2016), s. 4157-4179 ISSN 0022-0396 R&D Projects: GA ČR GAP201/10/0752 Institutional support: RVO:67985556 Keywords : stochastic partial differential equation * stochastic beam equation * stochastic wave equation * invariant measure Subject RIV: BA - General Mathematics Impact factor: 1.988, year: 2016 http://library.utia.cas.cz/separaty/2016/SI/ondrejat-0453412.pdf

Local invariants in non-ideal flows of neutral fluids and two-fluid plasmas

Science.gov (United States)

Zhu, Jian-Zhou

2018-03-01

The main objective is the locally invariant geometric object of any (magneto-)fluid dynamics with forcing and damping (nonideal), while more attention is paid to the untouched dynamical properties of two-fluid fashion. Specifically, local structures, beyond the well-known "frozen-in" to the barotropic flows of the generalized vorticities, of the two-fluid model of plasma flows are presented. More general non-barotropic situations are also considered. A modified Euler equation [T. Tao, "Finite time blowup for Lagrangian modifications of the three-dimensional Euler equation," Ann. PDE 2, 9 (2016)] is also accordingly analyzed and remarked from the angle of view of the two-fluid model, with emphasis on the local structures. The local constraints of high-order differential forms such as helicity, among others, find simple formulation for possible practices in modeling the dynamics. Thus, the Cauchy invariants equation [N. Besse and U. Frisch, "Geometric formulation of the Cauchy invariants for incompressible Euler flow in flat and curved spaces," J. Fluid Mech. 825, 412 (2017)] may be enabled to find applications in non-ideal flows. Some formal examples are offered to demonstrate the calculations, and particularly interestingly the two-dimensional-three-component (2D3C) or the 2D passive scalar problem presents that a locally invariant Θ = 2θζ, with θ and ζ being, respectively, the scalar value of the "vertical velocity" (or the passive scalar) and the "vertical vorticity," may be used as if it were the spatial density of the globally invariant helicity, providing a Lagrangian prescription to control the latter in some situations of studying its physical effects in rapidly rotating flows (ubiquitous in atmosphere of astrophysical objects) with marked 2D3C vortical modes or in purely 2D passive scalars.

Conformal invariance and two-dimensional physics

International Nuclear Information System (INIS)

Zuber, J.B.

1993-01-01

Actually, physicists and mathematicians are very interested in conformal invariance: geometric transformations which keep angles. This symmetry is very important for two-dimensional systems as phase transitions, string theory or node mathematics. In this article, the author presents the conformal invariance and explains its usefulness

Pattern recognition: invariants in 3D

International Nuclear Information System (INIS)

Proriol, J.

1992-01-01

In e + e - events, the jets have a spherical 3D symmetry. A set of invariants are defined for 3D objects with a spherical symmetry. These new invariants are used to tag the number of jets in e + e - events. (K.A.) 3 refs

A test for ordinal measurement invariance

NARCIS (Netherlands)

Ligtvoet, R.; Millsap, R.E.; Bolt, D.M.; van der Ark, L.A.; Wang, W.-C.

2015-01-01

One problem with the analysis of measurement invariance is the reliance of the analysis on having a parametric model that accurately describes the data. In this paper an ordinal version of the property of measurement invariance is proposed, which relies only on nonparametric restrictions. This

Inflation in a Scale Invariant Universe

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Pedro G. [Oxford U.; Hill, Christopher T. [Fermilab; Noller, Johannes [Zurich U.; Ross, Graham G. [Oxford U., Theor. Phys.

2018-02-16

A scale-invariant universe can have a period of accelerated expansion at early times: inflation. We use a frame-invariant approach to calculate inflationary observables in a scale invariant theory of gravity involving two scalar fields - the spectral indices, the tensor to scalar ratio, the level of isocurvature modes and non-Gaussianity. We show that scale symmetry leads to an exact cancellation of isocurvature modes and that, in the scale-symmetry broken phase, this theory is well described by a single scalar field theory. We find the predictions of this theory strongly compatible with current observations.

Adiabatic invariants of the extended KdV equation

Energy Technology Data Exchange (ETDEWEB)

Karczewska, Anna [Faculty of Mathematics, Computer Science and Econometrics, University of Zielona Góra, Szafrana 4a, 65-246 Zielona Góra (Poland); Rozmej, Piotr, E-mail: p.rozmej@if.uz.zgora.pl [Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, Szafrana 4a, 65-246 Zielona Góra (Poland); Infeld, Eryk [National Centre for Nuclear Research, Hoża 69, 00-681 Warszawa (Poland); Rowlands, George [Department of Physics, University of Warwick, Coventry, CV4 7A (United Kingdom)

2017-01-30

When the Euler equations for shallow water are taken to the next order, beyond KdV, momentum and energy are no longer exact invariants. (The only one is mass.) However, adiabatic invariants (AI) can be found. When the KdV expansion parameters are zero, exact invariants are recovered. Existence of adiabatic invariants results from general theory of near-identity transformations (NIT) which allow us to transform higher order nonintegrable equations to asymptotically equivalent (when small parameters tend to zero) integrable form. Here we present a direct method of calculations of adiabatic invariants. It does not need a transformation to a moving reference frame nor performing a near-identity transformation. Numerical tests show that deviations of AI from constant values are indeed small. - Highlights: • We suggest a new and simple method for calculating adiabatic invariants of second order wave equations. • It is easy to use and we hope that it will be useful if published. • Interesting numerics included.

Reliability, convergent validity and factor structure of the DASS-21 in a sample of Vietnamese adolescents.

Science.gov (United States)

Le, Minh Thi Hong; Tran, Thach Duc; Holton, Sara; Nguyen, Huong Thanh; Wolfe, Rory; Fisher, Jane

2017-01-01

To assess the internal consistency, latent structure and convergent validity of the Depression, Anxiety and Stress Scale-21 (DASS-21) among adolescents in Vietnam. An anonymous, self-completed questionnaire was conducted among 1,745 high school students in Hanoi, Vietnam between October, 2013 and January, 2014. Confirmatory factor analyses were performed to assess the latent structure of the DASS-21. Factorial invariance between girls and boys was examined. Cronbach alphas and correlation coefficients between DASS-21 factor scores and the domain scores of the Duke Health Profile Adolescent Vietnamese validated version (ADHP-V) were calculated to assess DASS-21 internal consistency and convergent validity. A total of 1,606/ 1,745 (92.6%) students returned the questionnaire. Of those, 1,387 students provided complete DASS-21 data. The scale demonstrated adequate internal consistency (Cronbach α: 0.761 to 0.906). A four-factor model showed the best fit to the data. Items loaded significantly on a common general distress factor, the depression, and the anxiety factors, but few on the stress factor (pDASS-21 convergent validity was confirmed with moderate correlation coefficients (-0.47 to -0.66) between its factor scores and the ADHP-V mental health related domains. The DASS-21 is reliable and suitable for use to assess symptoms of common mental health problems, especially depression and anxiety among Vietnamese adolescents. However, its ability in detecting stress among these adolescents may be limited. Further research is warrant to explore these results.

Gromov-Witten invariants and localization

Science.gov (United States)

Morrison, David R.

2017-11-01

We give a pedagogical review of the computation of Gromov-Witten invariants via localization in 2D gauged linear sigma models. We explain the relationship between the two-sphere partition function of the theory and the Kähler potential on the conformal manifold. We show how the Kähler potential can be assembled from classical, perturbative, and non-perturbative contributions, and explain how the non-perturbative contributions are related to the Gromov-Witten invariants of the corresponding Calabi-Yau manifold. We then explain how localization enables efficient calculation of the two-sphere partition function and, ultimately, the Gromov-Witten invariants themselves. This is a contribution to the review issue ‘Localization techniques in quantum field theories’ (ed V Pestun and M Zabzine) which contains 17 chapters, available at [1].

Invariant Theory for Dispersed Transverse Isotropy: An Efficient Means for Modeling Fiber Splay

Science.gov (United States)

Freed, alan D.; Einstein, Daniel R.; Vesely, Ivan

2004-01-01

Most soft tissues possess an oriented architecture of collagen fiber bundles, conferring both anisotropy and nonlinearity to their elastic behavior. Transverse isotropy has often been assumed for a subset of these tissues that have a single macroscopically-identifiable preferred fiber direction. Micro-structural studies, however, suggest that, in some tissues, collagen fibers are approximately normally distributed about a mean preferred fiber direction. Structural constitutive equations that account for this dispersion of fibers have been shown to capture the mechanical complexity of these tissues quite well. Such descriptions, however, are computationally cumbersome for two-dimensional (2D) fiber distributions, let alone for fully three-dimensional (3D) fiber populations. In this paper, we develop a new constitutive law for such tissues, based on a novel invariant theory for dispersed transverse isotropy. The invariant theory is based on a novel closed-form splay invariant that can easily handle 3D fiber populations, and that only requires a single parameter in the 2D case. The model is polyconvex and fits biaxial data for aortic valve tissue as accurately as the standard structural model. Modification of the fiber stress-strain law requires no re-formulation of the constitutive tangent matrix, making the model flexible for different types of soft tissues. Most importantly, the model is computationally expedient in a finite-element analysis.

Holography beyond conformal invariance and AdS isometry?

CERN Document Server

Barvinsky, A.O.

2015-01-01

We suggest that the principle of holographic duality can be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem from the bulk spacetime. This relation holds for operators of general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous $O(N^0)$ tests of AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies and conformal anomalies. The generalized holographic duality is discussed within the concept of the "double-trace" deformation of the boundary theory, which is responsible in the case of large $N$ CFT coupled to the tower of higher spin gauge fields for t...

Noncommutative field theory and violation of translation invariance

International Nuclear Information System (INIS)

Bertolami, Orfeu; Guisado, Luis

2003-01-01

Noncommutative field theories with commutator of the coordinates of the form [x μ , x ν ] = i Λ μν ω x ω with nilpotent structure constants are studied and shown that a free quantum field theory is not affected. Invariance under translations is broken and the conservation of energy-momentum is violated, obeying a new law which is expressed by a Poincare-invariant equation. The resulting new kinematics is studied and applied to simple examples and to astrophysical puzzles, such as the observed violation of the GZK cutoff. The λΦ 4 quantum field theory is also considered in this context. In particular, self interaction terms violate the usual conservation of energy-momentum and, hence, the radiative correction to the propagator is altered. The correction to first order in λ is calculated. The usual UV divergent terms are still present, but a new type of term also emerges, which is IR divergent, violates momentum conservation and implies a correction to the dispersion relation. (author)

Trait Emotional Intelligence and Personality: Gender-Invariant Linkages Across Different Measures of the Big Five.

OpenAIRE

Siegling, A. B.; Furnham, A.; Petrides, K. V.

2015-01-01

This study investigated if the linkages between trait emotional intelligence (trait EI) and the Five-Factor Model of personality were invariant between men and women. Five English-speaking samples (N = 307-685) of mostly undergraduate students each completed a different measure of the Big Five personality traits and either the full form or short form of the Trait Emotional Intelligence Questionnaire (TEIQue). Across samples, models predicting global TEIQue scores from the Big Five were invari...

Invariance identities associated with finite gauge transformations and the uniqueness of the equations of motion of a particle in a classical gauge field

International Nuclear Information System (INIS)

Rund, H.

1984-01-01

A certain class of geometric objects is considered against the background of a classical gauge field associated with an arbitrary structural Lie group. It is shown that the necessary and sufficient conditions for the invariance of the given objects under a finite gauge transformation are embodied in a set of three relations involving the derivatives of their components. As a special case these so-called invariance identities indicate that there cannot exist a gauge-invariant Lagrangian that depends on the gauge potentials, the interaction parameters, and the 4-velocity components of a test particle. However, the requirement that the equations of motion that result from such a lagrangian be gauge-invariant, uniquely determines the structure of these equations. (author)

Evaluation of the Gratitude Questionnaire in a Chinese Sample of Adults: Factorial Validity, Criterion-Related Validity, and Measurement Invariance Across Sex.

Science.gov (United States)

Kong, Feng; You, Xuqun; Zhao, Jingjing

2017-01-01

The Gratitude Questionnaire (GQ; McCullough et al., 2002) is one of the most widely used instruments to assess dispositional gratitude. The purpose of this study was to validate a Chinese version of the GQ by examining internal consistency, factor structure, convergent validity, and measurement invariance across sex. A total of 1151 Chinese adults were recruited to complete the GQ, Positive Affect and Negative Affect Scales, and Satisfaction with Life Scale. Confirmatory factor analysis indicated that the original unidimensional model fitted well, which is in accordance with the findings in Western populations. Furthermore, the GQ had satisfactory composite reliability and criterion-related validity with measures of life satisfaction and affective well-being. Evidence of configural, metric and scalar invariance across sex was obtained. Tests of the latent mean differences found females had higher latent mean scores than males. These findings suggest that the Chinese version of GQ is a reliable and valid tool for measuring dispositional gratitude and can generally be utilized across sex in the Chinese context.

The Hierarchical Factor Model of ADHD: Invariant across Age and National Groupings?

Science.gov (United States)

Toplak, Maggie E.; Sorge, Geoff B.; Flora, David B.; Chen, Wai; Banaschewski, Tobias; Buitelaar, Jan; Ebstein, Richard; Eisenberg, Jacques; Franke, Barbara; Gill, Michael; Miranda, Ana; Oades, Robert D.; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph; Sonuga-Barke, Edmund; Steinhausen, Hans-Christoph; Thompson, Margaret; Tannock, Rosemary; Asherson, Philip; Faraone, Stephen V.

2012-01-01

Objective: To examine the factor structure of attention-deficit/hyperactivity disorder (ADHD) in a clinical sample of 1,373 children and adolescents with ADHD and their 1,772 unselected siblings recruited from different countries across a large age range. Hierarchical and correlated factor analytic models were compared separately in the ADHD and…

Gauge-invariant dynamical quantities of QED with decomposed gauge potentials

International Nuclear Information System (INIS)

Zhou Baohua; Huang Yongchang

2011-01-01

We discover an inner structure of the QED system; i.e., by decomposing the gauge potential into two orthogonal components, we obtain a new expansion of the Lagrangian for the electron-photon system, from which, we realize the orthogonal decomposition of the canonical momentum conjugate to the gauge potential with the canonical momentum's two components conjugate to the gauge potential's two components, respectively. Using the new expansion of Lagrangian and by the general method of field theory, we naturally derive the gauge invariant separation of the angular momentum of the electron-photon system from Noether theorem, which is the rational one and has the simplest form in mathematics, compared with the other four versions of the angular momentum separation available in literature. We show that it is only the longitudinal component of the gauge potential that is contained in the orbital angular momentum of the electron, as Chen et al. have said. A similar gauge invariant separation of the momentum is given. The decomposed canonical Hamiltonian is derived, from which we construct the gauge invariant energy operator of the electron moving in the external field generated by a proton [Phys. Rev. A 82, 012107 (2010)], where we show that the form of the kinetic energy containing the longitudinal part of the gauge potential is due to the intrinsic requirement of the gauge invariance. Our method provides a new perspective to look on the nucleon spin crisis and indicates that this problem can be solved strictly and systematically.

Affine invariants of convex polygons.

Science.gov (United States)

Flusser, Jan

2002-01-01

In this correspondence, we prove that the affine invariants, for image registration and object recognition, proposed recently by Yang and Cohen (see ibid., vol.8, no.7, p.934-46, July 1999) are algebraically dependent. We show how to select an independent and complete set of the invariants. The use of this new set leads to a significant reduction of the computing complexity without decreasing the discrimination power.

Notes on algebraic invariants for non-commutative dynamical systems

Energy Technology Data Exchange (ETDEWEB)

Longo, R [Rome Univ. (Italy). Istituto di Matematica

1979-11-01

We consider an algebraic invariant for non-commutative dynamical systems naturally arising as the spectrum of the modular operator associated to an invariant state, provided certain conditions of mixing type are present. This invariant turns out to be exactly the annihilator of the invariant T of Connes. Further comments are included, in particular on the type of certain algebras of local observables

On the factor structure of the Rosenberg (1965) General Self-Esteem Scale.

Science.gov (United States)

Alessandri, Guido; Vecchione, Michele; Eisenberg, Nancy; Łaguna, Mariola

2015-06-01

Since its introduction, the Rosenberg General Self-Esteem Scale (RGSE, Rosenberg, 1965) has been 1 of the most widely used measures of global self-esteem. We conducted 4 studies to investigate (a) the goodness-of-fit of a bifactor model positing a general self-esteem (GSE) factor and 2 specific factors grouping positive (MFP) and negative items (MFN) and (b) different kinds of validity of the GSE, MFN, and MFP factors of the RSGE. In the first study (n = 11,028), the fit of the bifactor model was compared with those of 9 alternative models proposed in literature for the RGSE. In Study 2 (n = 357), the external validities of GSE, MFP, and MFN were evaluated using objective grade point average data and multimethod measures of prosociality, aggression, and depression. In Study 3 (n = 565), the across-rater robustness of the bifactor model was evaluated. In Study 4, measurement invariance of the RGSE was further supported across samples in 3 European countries, Serbia (n = 1,010), Poland (n = 699), and Italy (n = 707), and in the United States (n = 1,192). All in all, psychometric findings corroborate the value and the robustness of the bifactor structure and its substantive interpretation. (c) 2015 APA, all rights reserved).

The Impact of Partial Measurement Invariance on Testing Moderation for Single and Multi-Level Data.

Science.gov (United States)

Hsiao, Yu-Yu; Lai, Mark H C

2018-01-01

Moderation effect is a commonly used concept in the field of social and behavioral science. Several studies regarding the implication of moderation effects have been done; however, little is known about how partial measurement invariance influences the properties of tests for moderation effects when categorical moderators were used. Additionally, whether the impact is the same across single and multilevel data is still unknown. Hence, the purpose of the present study is twofold: (a) To investigate the performance of the moderation test in single-level studies when measurement invariance does not hold; (b) To examine whether unique features of multilevel data, such as intraclass correlation (ICC) and number of clusters, influence the effect of measurement non-invariance on the performance of tests for moderation. Simulation results indicated that falsely assuming measurement invariance lead to biased estimates, inflated Type I error rates, and more gain or more loss in power (depends on simulation conditions) for the test of moderation effects. Such patterns were more salient as sample size and the number of non-invariant items increase for both single- and multi-level data. With multilevel data, the cluster size seemed to have a larger impact than the number of clusters when falsely assuming measurement invariance in the moderation estimation. ICC was trivially related to the moderation estimates. Overall, when testing moderation effects with categorical moderators, employing a model that accounts for the measurement (non)invariance structure of the predictor and/or the outcome is recommended.

Cross-cultural measurement invariance in the satisfaction with food-related life scale in older adults from two developing countries.

Science.gov (United States)

Schnettler, Berta; Miranda-Zapata, Edgardo; Lobos, Germán; Lapo, María; Grunert, Klaus G; Adasme-Berríos, Cristian; Hueche, Clementina

2017-05-30

Nutrition is one of the major determinants of successful aging. The Satisfaction with Food-related Life (SWFL) scale measures a person's overall assessment regarding their food and eating habits. The SWFL scale has been used in older adult samples across different countries in Europe, Asia and America, however, there are no studies that have evaluated the cross-cultural measurement invariance of the scale in older adult samples. Therefore, we evaluated the measurement invariance of the SWFL scale across older adults from Chile and Ecuador. Stratified random sampling was used to recruit a sample of older adults of both genders from Chile (mean age = 71.38, SD = 6.48, range = 60-92) and from Ecuador (mean age = 73.70, SD = 7.45, range = 60-101). Participants reported their levels of satisfaction with food-related life by completing the SWFL scale, which consists of five items grouped into a single dimension. Confirmatory factor analysis (CFA) was used to examine cross-cultural measurement invariance of the SWFL scale. Results showed that the SWFL scale exhibited partial measurement invariance, with invariance of all factor loadings, invariance in all but one item's threshold (item 1) and invariance in all items' uniqueness (residuals), which leads us to conclude that there is a reasonable level of partial measurement invariance for the CFA model of the SWFL scale, when comparing the Chilean and Ecuadorian older adult samples. The lack of invariance in item 1 confirms previous studies with adults and emerging adults in Chile that suggest this item is culture-sensitive. We recommend revising the wording of the first item of the SWFL in order to relate the statement with the person's life. The SWFL scale shows partial measurement invariance across older adults from Chile and Ecuador. A 4-item version of the scale (excluding item 1) provides the basis for international comparisons of satisfaction with food-related life in older adults from developing

Soil water content evaluation considering time-invariant spatial pattern and space-variant temporal change

Science.gov (United States)

Hu, W.; Si, B. C.

2013-10-01

Soil water content (SWC) varies in space and time. The objective of this study was to evaluate soil water content distribution using a statistical model. The model divides spatial SWC series into time-invariant spatial patterns, space-invariant temporal changes, and space- and time-dependent redistribution terms. The redistribution term is responsible for the temporal changes in spatial patterns of SWC. An empirical orthogonal function was used to separate the total variations of redistribution terms into the sum of the product of spatial structures (EOFs) and temporally-varying coefficients (ECs). Model performance was evaluated using SWC data of near-surface (0-0.2 m) and root-zone (0-1.0 m) from a Canadian Prairie landscape. Three significant EOFs were identified for redistribution term for both soil layers. EOF1 dominated the variations of redistribution terms and it resulted in more changes (recharge or discharge) in SWC at wetter locations. Depth to CaCO3 layer and organic carbon were the two most important controlling factors of EOF1, and together, they explained over 80% of the variations in EOF1. Weak correlation existed between either EOF2 or EOF3 and the observed factors. A reasonable prediction of SWC distribution was obtained with this model using cross validation. The model performed better in the root zone than in the near surface, and it outperformed conventional EOF method in case soil moisture deviated from the average conditions.

Psychometric evaluation of Persian Nomophobia Questionnaire: Differential item functioning and measurement invariance across gender.

Science.gov (United States)

Lin, Chung-Ying; Griffiths, Mark D; Pakpour, Amir H

2018-03-01

Background and aims Research examining problematic mobile phone use has increased markedly over the past 5 years and has been related to "no mobile phone phobia" (so-called nomophobia). The 20-item Nomophobia Questionnaire (NMP-Q) is the only instrument that assesses nomophobia with an underlying theoretical structure and robust psychometric testing. This study aimed to confirm the construct validity of the Persian NMP-Q using Rasch and confirmatory factor analysis (CFA) models. Methods After ensuring the linguistic validity, Rasch models were used to examine the unidimensionality of each Persian NMP-Q factor among 3,216 Iranian adolescents and CFAs were used to confirm its four-factor structure. Differential item functioning (DIF) and multigroup CFA were used to examine whether males and females interpreted the NMP-Q similarly, including item content and NMP-Q structure. Results Each factor was unidimensional according to the Rach findings, and the four-factor structure was supported by CFA. Two items did not quite fit the Rasch models (Item 14: "I would be nervous because I could not know if someone had tried to get a hold of me;" Item 9: "If I could not check my smartphone for a while, I would feel a desire to check it"). No DIF items were found across gender and measurement invariance was supported in multigroup CFA across gender. Conclusions Due to the satisfactory psychometric properties, it is concluded that the Persian NMP-Q can be used to assess nomophobia among adolescents. Moreover, NMP-Q users may compare its scores between genders in the knowledge that there are no score differences contributed by different understandings of NMP-Q items.

The astigmatism factor for semiconductor injection lasers

International Nuclear Information System (INIS)

Zhao Yiguang; Guo Changzhi

1988-03-01

The relations between the astigmatism factor and the waveguide structure, working conditions etc. were accurately calculated, using a method for deriving a self-consistent solution of the optical field equation and the carrier diffusion equation. Various theoretical models regarding the spontaneous emission factor were analyzed and compared. The results show that there is a difference between astigmatism factors of semiconductor lasers with different waveguide structures. W. Streifer's results, for a model having an invariable distribution of the complex refractive index, are larger by a factor of 6 to 80 than the accurate calculated value. K. Petermann's theory regarding the spontaneous emission factor is more appropriate than other theories. (author). 19 refs, 6 figs

Examination of Longitudinal Invariance on a Framework for Observing and Categorizing Instructional Strategies

Science.gov (United States)

Ryoo, Ji Hoon; Tai, Robert H.; Skeeles-Worley, Angela D.

2018-02-01

In longitudinal studies, measurement invariance is required to conduct substantive comparisons over time or across groups. In this study, we examined measurement invariance on a recently developed instrument capturing student preferences for seven instructional strategies related to science learning and career interest. We have labeled these seven instructional strategies as Collaborating, Competing, Caretaking, Creating/Making, Discovering, Performing, and Teaching. A better understanding of student preferences for particular instructional strategies can help educators, researchers, and policy makers deliberately tailor programmatic instructional structure to increase student persistence in the STEM pipeline. However, simply confirming the relationship between student preferences for science instructional strategies and their future career choices at a single time point is not sufficient to clarify our understanding of the relationship between instructional strategies and student persistence in the STEM pipeline, especially since preferences for instructional strategies are understood to vary over time. As such, we sought to develop a measure that invariantly captures student preference over a period of time: the Framework for Observing and Categorizing Instructional Strategies (FOCIS). We administered the FOCIS instrument over four semesters over two middle school grades to 1009 6th graders and 1021 7th graders and confirmed the longitudinal invariance of the FOCIS measure. This confirmation of longitudinal invariance will allow researchers to examine the relationship between student preference for certain instructional strategies and student persistence in the STEM pipeline.

Quantum tunneling, adiabatic invariance and black hole spectroscopy

Science.gov (United States)

Li, Guo-Ping; Pu, Jin; Jiang, Qing-Quan; Zu, Xiao-Tao

2017-05-01

In the tunneling framework, one of us, Jiang, together with Han has studied the black hole spectroscopy via adiabatic invariance, where the adiabatic invariant quantity has been intriguingly obtained by investigating the oscillating velocity of the black hole horizon. In this paper, we attempt to improve Jiang-Han's proposal in two ways. Firstly, we once again examine the fact that, in different types (Schwarzschild and Painlevé) of coordinates as well as in different gravity frames, the adiabatic invariant I_adia = \\oint p_i dq_i introduced by Jiang and Han is canonically invariant. Secondly, we attempt to confirm Jiang-Han's proposal reasonably in more general gravity frames (including Einstein's gravity, EGB gravity and HL gravity). Concurrently, for improving this proposal, we interestingly find in more general gravity theories that the entropy of the black hole is an adiabatic invariant action variable, but the horizon area is only an adiabatic invariant. In this sense, we emphasize the concept that the quantum of the black hole entropy is more natural than that of the horizon area.

Gauge-invariant approach and infrared behaviour of the spinor propagator

International Nuclear Information System (INIS)

Sisakyan, A.N.; Skachkov, N.B.; Solovtsov, I.L.; Shevchenko, O.Yu.

1989-01-01

Infrared behaviour of the gauge-invariant spinor propagator is studied. It is proved that infrared peculiarities of such a propagator can be factorized in a form of the Wilson loop that includes only the slowly varying component of electromagnetic field and accumulates all the dependence of the initial Green function of the form of the path

Invariant length scale in relativistic kinematics: lessons from Dirichlet branes

International Nuclear Information System (INIS)

Schuller, Frederic P.; Pfeiffer, Hendryk

2004-01-01

Dirac-Born-Infeld theory is shown to possess a hidden invariance associated with its maximal electric field strength. The local Lorentz symmetry O(1,n) on a Dirichlet-n-brane is thereby enhanced to an O(1,n)xO(1,n) gauge group, encoding both an invariant velocity and acceleration (or length) scale. The presence of this enlarged gauge group predicts consequences for the kinematics of observers on Dirichlet branes, with admissible accelerations being bounded from above. An important lesson is that the introduction of a fundamental length scale into relativistic kinematics does not enforce a deformation of Lorentz boosts, as one might assume naively. The exhibited structures further show that Moffat's non-symmetric gravitational theory qualifies as a candidate for a consistent Born-Infeld type gravity with regulated solutions

Modular invariance, chiral anomalies and contact terms

International Nuclear Information System (INIS)

Kutasov, D.

1988-03-01

The chiral anomaly in heterotic strings with full and partial modular invariance in D=2n+2 dimensions is calculated. The boundary terms which were present in previous calculations are shown to be cancelled in the modular invariant case by contact terms, which can be obtained by an appropriate analytic continuation. The relation to the low energy field theory is explained. In theories with partial modular invariance, an expression for the anomaly is obtained and shown to be non zero in general. (author)

Strong coupling in a gauge invariant field theory

Energy Technology Data Exchange (ETDEWEB)

Johnson, K. [Physics Department, Massachusetts Institute of Technology, Cambridge, MA (United States)

1963-01-15

I would like to discuss some approximations which may be significant in the domain of strong coupling in a field system analogous to quantum electrodynamics. The motivation of this work is the idea that the strong couplings and elementary particle spectrum may be the consequence of the dynamics of a system whose underlying description is in terms of a set of Fermi fields gauge invariantly coupled to a single (''bare'') massless neutral vector field. The basis of this gauge invariance would of course be the exact conservation law of baryons or ''nucleonic charge''. It seems to me that a coupling scheme based on an invariance principle is most attractive if that invariance is an exact one. It would then be nice to try to account for the approximate invariance principles in the same way one would describe ''accidental degeneracies'' in any quantum system.

Structure and clinical correlates of obsessive–compulsive symptoms in a large sample of children and adolescents

DEFF Research Database (Denmark)

Højgaard, D. R M A; Mortensen, E. L.; Ivarsson, Tord

2017-01-01

/cleaning. The factor structure was invariant for age and gender across subgroups. Factor one was significantly correlated with anxiety, and factor two with depression and anxiety. Factor three was negatively correlated with tic disorder and attention-deficit/hyperactivity disorder (ADHD). Females had higher scores...

Invariant and partially-invariant solutions of the equations describing a non-stationary and isentropic flow for an ideal and compressible fluid in (3 + 1) dimensions

Science.gov (United States)

Grundland, A. M.; Lalague, L.

1996-04-01

This paper presents a new method of constructing, certain classes of solutions of a system of partial differential equations (PDEs) describing the non-stationary and isentropic flow for an ideal compressible fluid. A generalization of the symmetry reduction method to the case of partially-invariant solutions (PISs) has been formulated. We present a new algorithm for constructing PISs and discuss in detail the necessary conditions for the existence of non-reducible PISs. All these solutions have the defect structure 0305-4470/29/8/019/img1 and are computed from four-dimensional symmetric subalgebras. These theoretical considerations are illustrated by several examples. Finally, some new classes of invariant solutions obtained by the symmetry reduction method are included. These solutions represent central, conical, rational, spherical, cylindrical and non-scattering double waves.

Comparing the Psychometric Properties of Two Physical Activity Self-Efficacy Instruments in Urban, Adolescent Girls: Validity, Measurement Invariance, and Reliability

Science.gov (United States)

Voskuil, Vicki R.; Pierce, Steven J.; Robbins, Lorraine B.

2017-01-01

Aims: This study compared the psychometric properties of two self-efficacy instruments related to physical activity. Factorial validity, cross-group and longitudinal invariance, and composite reliability were examined. Methods: Secondary analysis was conducted on data from a group randomized controlled trial investigating the effect of a 17-week intervention on increasing moderate to vigorous physical activity among 5th–8th grade girls (N = 1,012). Participants completed a 6-item Physical Activity Self-Efficacy Scale (PASE) and a 7-item Self-Efficacy for Exercise Behaviors Scale (SEEB) at baseline and post-intervention. Confirmatory factor analyses for intervention and control groups were conducted with Mplus Version 7.4 using robust weighted least squares estimation. Model fit was evaluated with the chi-square index, comparative fit index, and root mean square error of approximation. Composite reliability for latent factors with ordinal indicators was computed from Mplus output using SAS 9.3. Results: Mean age of the girls was 12.2 years (SD = 0.96). One-third of the girls were obese. Girls represented a diverse sample with over 50% indicating black race and an additional 19% identifying as mixed or other race. Both instruments demonstrated configural invariance for simultaneous analysis of cross-group and longitudinal invariance based on alternative fit indices. However, simultaneous metric invariance was not met for the PASE or the SEEB instruments. Partial metric invariance for the simultaneous analysis was achieved for the PASE with one factor loading identified as non-invariant. Partial metric invariance was not met for the SEEB. Longitudinal scalar invariance was achieved for both instruments in the control group but not the intervention group. Composite reliability for the PASE ranged from 0.772 to 0.842. Reliability for the SEEB ranged from 0.719 to 0.800 indicating higher reliability for the PASE. Reliability was more stable over time in the control

Translation invariance, commutation relations and ultraviolet/infrared mixing

International Nuclear Information System (INIS)

Galluccio, Salvatore; Lizzi, Fedele; Vitale, Patrizia

2009-01-01

We show that the Ultraviolet/Infrared mixing of noncommutative field theories with the Groenewold-Moyal product, whereby some (but not all) ultraviolet divergences become infrared, is a generic feature of translationally invariant associative products. We find, with an explicit calculation that the phase appearing in the nonplanar diagrams is the one given by the commutator of the coordinates, the semiclassical Poisson structure of the non commutative spacetime. We do this with an explicit calculation for represented generic products.

Quantum Hall Conductivity and Topological Invariants

Science.gov (United States)

Reyes, Andres

2001-04-01

A short survey of the theory of the Quantum Hall effect is given emphasizing topological aspects of the quantization of the conductivity and showing how topological invariants can be derived from the hamiltonian. We express these invariants in terms of Chern numbers and show in precise mathematical terms how this relates to the Kubo formula.

Gender Invariance of Family, School, and Peer Influence on Volunteerism Scale

Science.gov (United States)

Law, Ben; Shek, Daniel; Ma, Cecilia

2015-01-01

Objective: This article examines the measurement invariance of "Family, School, and Peer Influence on Volunteerism Scale" (FSPV) across genders using the mean and covariance structure analysis approach. Method: A total of 2,845 Chinese high school adolescents aged 11 to 15 years completed the FSPV scale. Results: Results of the…

Quantized gauge invariant periodic TDHF solutions

International Nuclear Information System (INIS)

Kan, K.-K.; Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.

1979-01-01

Time-dependent Hartree-Fock (TDHF) is used to study steady state large amplitude nuclear collective motions, such as vibration and rotation. As is well known the small amplitude TDHF leads to the RPA equation. The analysis of periodicity in TDHF is not trivial because TDHF is a nonlinear theory and it is not known under what circumstances a nonlinear theory can support periodic solutions. It is also unknown whether such periodic solution, if they exist, form a continuous or a discrete set. But, these properties may be important in obtaining the energy spectrum of the collective states from the TDHF description. The periodicity and Gauge Invariant Periodicity of solutions are investigated for that class of models whose TDHF solutions depend on time through two parameters. In such models TDHF supports a continuous family of periodic solutions, but only a discrete subset of these is gauge invariant. These discrete Gauge Invariant Periodic solutions obey the Bohr-Summerfeld quantization rule. The energy spectrum of the Gauge Invariant Periodic solutions is compared with the exact eigenergies in one specific example

Classification of simple current invariants

CERN Document Server

Gato-Rivera, Beatriz

1992-01-01

We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)

Fully Numerical Methods for Continuing Families of Quasi-Periodic Invariant Tori in Astrodynamics

Science.gov (United States)

Baresi, Nicola; Olikara, Zubin P.; Scheeres, Daniel J.

2018-01-01

Quasi-periodic invariant tori are of great interest in astrodynamics because of their capability to further expand the design space of satellite missions. However, there is no general consent on what is the best methodology for computing these dynamical structures. This paper compares the performance of four different approaches available in the literature. The first two methods compute invariant tori of flows by solving a system of partial differential equations via either central differences or Fourier techniques. In contrast, the other two strategies calculate invariant curves of maps via shooting algorithms: one using surfaces of section, and one using a stroboscopic map. All of the numerical procedures are tested in the co-rotating frame of the Earth as well as in the planar circular restricted three-body problem. The results of our numerical simulations show which of the reviewed procedures should be preferred for future studies of astrodynamics systems.

Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students

DEFF Research Database (Denmark)

Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo

2017-01-01

This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non......-probabilistic longitudinal sampling, 114 university students (65.8% female, mean age: 22.5) completed the SWFL questionnaire three times, over intervals of approximately one year. Confirmatory factor analysis was used to examine longitudinal measurement invariance. Two types of analysis were conducted: first, a longitudinal...... students of both sexes, and among those older and younger than 22 years. Generally, these findings suggest that the SWFL scale has satisfactory psychometric properties for longitudinal measurement invariance in university students with similar characteristics as the students that participated...

Psychometric properties and measurement invariance of the Beck hopelessness scale (BHS): results from a German representative population sample.

Science.gov (United States)

Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar

2018-04-25

The Beck Hopelessness Scale (BHS) has been the most frequently used instrument for the measurement of hopelessness in the past 40 years. Only recently has it officially been translated into German. The psychometric properties and factor structure of the BHS have been cause for intensive debate in the past. Based on a representative sample of the German population (N = 2450) item analysis including item sensitivity, item-total correlation and item difficulty was performed. Confirmatory factor analyses (CFA) for several factor solutions from the literature were performed. Multiple group factor analysis was performed to assess measurement invariance. Construct validity was assessed via the replication of well-established correlations with concurrently assessed measures. Most items exhibited adequate properties. Items #4, #8 and #13 exhibited poor item characteristics- each of these items had previously received negative evaluations in international studies. A one-dimensional factor solution, favorable for the calculation and interpretation of a sum score, was regarded as adequate. A bi-factor model with one content factor and two method factors (defined by positive/negative item coding) resulted in an excellent model fit. Cronbach's alpha in the current sample was .87. Hopelessness, as measured by the BHS, significantly correlated in the expected direction with suicidal ideation (r = .36), depression (r = .53) and life satisfaction (r = -.53). Strict measurement invariance could be established regarding gender and depression status. Due to limited research regarding the interpretation of fit indices with dichotomous data, interpretation of CFA results needs to remain tentative. The BHS is a valid measure of hopelessness in various subgroups of the general population. Future research could aim at replicating these findings using item response theory and cross-cultural samples. A one-dimensional bi-factor model seems appropriate even in a non

Shape, smoothness and invariant stratification of an attracting set for delayed monotone positive feedback

CERN Document Server

Krisztin, Tibor; Wu, Jianhong

1998-01-01

This book contains recent results about the global dynamics defined by a class of delay differential equations which model basic feedback mechanisms and arise in a variety of applications such as neural networks. The authors describe in detail the geometric structure of a fundamental invariant set, which in special cases is the global attractor, and the asymptotic behavior of solution curves on it. The approach makes use of advanced tools which in recent years have been developed for the investigation of infinite-dimensional dynamical systems: local invariant manifolds and inclination lemmas f

Measurement invariance of the Mental Health Continuum-Short Form (MHC-SF) across three cultural groups

NARCIS (Netherlands)

Joshanloo, Mohsen; Wissing, Marie P.; Khumalo, Itumeleng P.; Lamers, S.M.A.

2013-01-01

This study investigated the factorial structure and invariance of the Mental Health Continuum-Short Form (MHC-SF) across cultural groups from three nations, namely, the Netherlands, South Africa, and Iran (N = 1120). The three-dimensional structure of mental well-being was supported in all the

The Whiteley Index-6: An Examination of Measurement Invariance Among Self-Identifying Black, Latino, and White Respondents in Primary Care.

Science.gov (United States)

Fergus, Thomas A; Kelley, Lance P; Griggs, Jackson O

2018-03-01

Brief measures that are comparable across disparate groups are particularly likely to be useful in primary care settings. Prior research has supported a six-item short form of the Whiteley Index (WI), a commonly used measure of health anxiety, among English-speaking respondents. This study examined the measurement invariance of the WI-6 among Black ( n = 183), Latino ( n = 173), and White ( n = 177) respondents seeking treatment at a U.S. community health center. Results supported a bifactor model of the WI-6 among the composite sample ( N = 533), suggesting the presence of a general factor and two domain-specific factors. Results supported the incremental validity of one of the domain-specific factors in accounting for unique variance in somatic symptom severity scores beyond the general factor. Multiple-groups confirmatory factor analysis supported the configural, metric, ands scalar invariance of the bifactor WI-6 model across the three groups of respondents. Results provide support for the measurement invariance of the WI-6 among Black, Latino, and White respondents. The potential use of the WI-6 in primary care, and broader, settings is discussed.

Quantum tunneling, adiabatic invariance and black hole spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Li, Guo-Ping; Zu, Xiao-Tao [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Pu, Jin [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); China West Normal University, College of Physics and Space Science, Nanchong (China); Jiang, Qing-Quan [China West Normal University, College of Physics and Space Science, Nanchong (China)

2017-05-15

In the tunneling framework, one of us, Jiang, together with Han has studied the black hole spectroscopy via adiabatic invariance, where the adiabatic invariant quantity has been intriguingly obtained by investigating the oscillating velocity of the black hole horizon. In this paper, we attempt to improve Jiang-Han's proposal in two ways. Firstly, we once again examine the fact that, in different types (Schwarzschild and Painleve) of coordinates as well as in different gravity frames, the adiabatic invariant I{sub adia} = circular integral p{sub i}dq{sub i} introduced by Jiang and Han is canonically invariant. Secondly, we attempt to confirm Jiang-Han's proposal reasonably in more general gravity frames (including Einstein's gravity, EGB gravity and HL gravity). Concurrently, for improving this proposal, we interestingly find in more general gravity theories that the entropy of the black hole is an adiabatic invariant action variable, but the horizon area is only an adiabatic invariant. In this sense, we emphasize the concept that the quantum of the black hole entropy is more natural than that of the horizon area. (orig.)

Evaluating measurement invariance across assessment modes of phone interview and computer self-administered survey for the PROMIS measures in a population-based cohort of localized prostate cancer survivors.

Science.gov (United States)

Wang, Mian; Chen, Ronald C; Usinger, Deborah S; Reeve, Bryce B

2017-11-01

To evaluate measurement invariance (phone interview vs computer self-administered survey) of 15 PROMIS measures responded by a population-based cohort of localized prostate cancer survivors. Participants were part of the North Carolina Prostate Cancer Comparative Effectiveness and Survivorship Study. Out of the 952 men who took the phone interview at 24 months post-treatment, 401 of them also completed the same survey online using a home computer. Unidimensionality of the PROMIS measures was examined using single-factor confirmatory factor analysis (CFA) models. Measurement invariance testing was conducted using longitudinal CFA via a model comparison approach. For strongly or partially strongly invariant measures, changes in the latent factors and factor autocorrelations were also estimated and tested. Six measures (sleep disturbance, sleep-related impairment, diarrhea, illness impact-negative, illness impact-positive, and global satisfaction with sex life) had locally dependent items, and therefore model modifications had to be made on these domains prior to measurement invariance testing. Overall, seven measures achieved strong invariance (all items had equal loadings and thresholds), and four measures achieved partial strong invariance (each measure had one item with unequal loadings and thresholds). Three measures (pain interference, interest in sexual activity, and global satisfaction with sex life) failed to establish configural invariance due to between-mode differences in factor patterns. This study supports the use of phone-based live interviewers in lieu of PC-based assessment (when needed) for many of the PROMIS measures.

Darboux invariants of integrable equations with variable spectral parameters

International Nuclear Information System (INIS)

Shin, H J

2008-01-01

The Darboux transformation for integrable equations with variable spectral parameters is introduced. Darboux invariant quantities are calculated, which are used in constructing the Lax pair of integrable equations. This approach serves as a systematic method for constructing inhomogeneous integrable equations and their soliton solutions. The structure functions of variable spectral parameters determine the integrability and nonlinear coupling terms. Three cases of integrable equations are treated as examples of this approach

Scale invariance, killing vectors, and the size of the fifth dimension

International Nuclear Information System (INIS)

Ross, D.K.

1986-01-01

An analysis is made of the classical five-dimensional sourceless Kaluza-Klein equations with the existence of the usual α/α/PSI/ Killing vector not assumed, where /PSI/ is the coordinate of the fifth dimension. The physical distance around the fifth dimension D 5 , needed for the calculation of the fine structure constant α, is not calculable in the usual theory because the equations have a global scale invariance. In the present case, the Killing vector and the global scale invariance are not present, but it is found rather generally that D 5 = 0. This indicates that quantum gravity is a necessary ingredient if α is to be calculated. It also provides an alternate explanation of why the universe appears four-dimensional

Dimuon Level-1 invariant mass in 2017 data

CERN Document Server

CMS Collaboration

2018-01-01

This document shows the Level-1 (L1) dimuon invariant mass with and without L1 muon track extrapolation to the collision vertex and how it compares with the offline reconstructed dimuon invariant mass. The plots are made with the data sample collected in 2017. The event selection, the matching algorithm and the results of the L1 dimuon invariant mass are described in the next pages.

A Balanced Comparison of Object Invariances in Monkey IT Neurons.

Science.gov (United States)

Ratan Murty, N Apurva; Arun, Sripati P

2017-01-01

Our ability to recognize objects across variations in size, position, or rotation is based on invariant object representations in higher visual cortex. However, we know little about how these invariances are related. Are some invariances harder than others? Do some invariances arise faster than others? These comparisons can be made only upon equating image changes across transformations. Here, we targeted invariant neural representations in the monkey inferotemporal (IT) cortex using object images with balanced changes in size, position, and rotation. Across the recorded population, IT neurons generalized across size and position both stronger and faster than to rotations in the image plane as well as in depth. We obtained a similar ordering of invariances in deep neural networks but not in low-level visual representations. Thus, invariant neural representations dynamically evolve in a temporal order reflective of their underlying computational complexity.

Reliability, convergent validity and factor structure of the DASS-21 in a sample of Vietnamese adolescents.

Directory of Open Access Journals (Sweden)

Minh Thi Hong Le

Full Text Available To assess the internal consistency, latent structure and convergent validity of the Depression, Anxiety and Stress Scale-21 (DASS-21 among adolescents in Vietnam.An anonymous, self-completed questionnaire was conducted among 1,745 high school students in Hanoi, Vietnam between October, 2013 and January, 2014. Confirmatory factor analyses were performed to assess the latent structure of the DASS-21. Factorial invariance between girls and boys was examined. Cronbach alphas and correlation coefficients between DASS-21 factor scores and the domain scores of the Duke Health Profile Adolescent Vietnamese validated version (ADHP-V were calculated to assess DASS-21 internal consistency and convergent validity.A total of 1,606/ 1,745 (92.6% students returned the questionnaire. Of those, 1,387 students provided complete DASS-21 data. The scale demonstrated adequate internal consistency (Cronbach α: 0.761 to 0.906. A four-factor model showed the best fit to the data. Items loaded significantly on a common general distress factor, the depression, and the anxiety factors, but few on the stress factor (p<0.05. DASS-21 convergent validity was confirmed with moderate correlation coefficients (-0.47 to -0.66 between its factor scores and the ADHP-V mental health related domains.The DASS-21 is reliable and suitable for use to assess symptoms of common mental health problems, especially depression and anxiety among Vietnamese adolescents. However, its ability in detecting stress among these adolescents may be limited. Further research is warrant to explore these results.

The structure of emotional and cognitive anxiety symptoms

DEFF Research Database (Denmark)

Kristensen, Ann Suhl; Mortensen, Erik Lykke; Mors, Ole

2009-01-01

A sample of 327 patients with primary panic disorder or social phobia completed a questionnaire comprising 77 emotional and cognitive anxiety symptoms from which 12 index scales were constructed. Explorative factor analysis yielded two factors, but confirmatory factor analysis indicated...... that the factor solution was not invariant across diagnoses. Nevertheless, the two-factor structures fitting data from patients with panic disorder and social phobia, respectively, had similarities in content. The first factor, emotions and cognitive-social concerns, comprised emotional expressions (sadness, fear...

Riemann quasi-invariants

International Nuclear Information System (INIS)

Pokhozhaev, Stanislav I

2011-01-01

The notion of Riemann quasi-invariants is introduced and their applications to several conservation laws are considered. The case of nonisentropic flow of an ideal polytropic gas is analysed in detail. Sufficient conditions for gradient catastrophes are obtained. Bibliography: 16 titles.

Does Gender-Specific Differential Item Functioning Affect the Structure in Vocational Interest Inventories?

Science.gov (United States)

Beinicke, Andrea; Pässler, Katja; Hell, Benedikt

2014-01-01

The study investigates consequences of eliminating items showing gender-specific differential item functioning (DIF) on the psychometric structure of a standard RIASEC interest inventory. Holland's hexagonal model was tested for structural invariance using a confirmatory methodological approach (confirmatory factor analysis and randomization…

Modular categories and 3-manifold invariants

International Nuclear Information System (INIS)

Tureav, V.G.

1992-01-01

The aim of this paper is to give a concise introduction to the theory of knot invariants and 3-manifold invariants which generalize the Jones polynomial and which may be considered as a mathematical version of the Witten invariants. Such a theory was introduced by N. Reshetikhin and the author on the ground of the theory of quantum groups. here we use more general algebraic objects, specifically, ribbon and modular categories. Such categories in particular arise as the categories of representations of quantum groups. The notion of modular category, interesting in itself, is closely related to the notion of modular tensor category in the sense of G. Moore and N. Seiberg. For simplicity we restrict ourselves in this paper to the case of closed 3-manifolds

Knot invariants and higher representation theory

CERN Document Server

Webster, Ben

2018-01-01

The author constructs knot invariants categorifying the quantum knot variants for all representations of quantum groups. He shows that these invariants coincide with previous invariants defined by Khovanov for \\mathfrak{sl}_2 and \\mathfrak{sl}_3 and by Mazorchuk-Stroppel and Sussan for \\mathfrak{sl}_n. The author's technique is to study 2-representations of 2-quantum groups (in the sense of Rouquier and Khovanov-Lauda) categorifying tensor products of irreducible representations. These are the representation categories of certain finite dimensional algebras with an explicit diagrammatic presentation, generalizing the cyclotomic quotient of the KLR algebra. When the Lie algebra under consideration is \\mathfrak{sl}_n, the author shows that these categories agree with certain subcategories of parabolic category \\mathcal{O} for \\mathfrak{gl}_k.

Measurement invariance of the Yale Food Addiction Scale 2.0 across gender and racial groups.

Science.gov (United States)

Carr, Meagan M; Catak, Pelin D; Pejsa-Reitz, Megan C; Saules, Karen K; Gearhardt, Ashley N

2017-08-01

Food addiction describes a psychological and behavioral eating pattern that is similar to the experience of those compulsively taking drugs of abuse. Recent developments related to food addiction, including the development and validation of an updated measure (Yale Food Addiction Scale 2.0; Gearhardt, Corbin, & Brownell, 2016), have increased knowledge as to the prevalence and associated correlates of food addiction. However, less is known about the phenomenological experience of food addiction in diverse samples or how the existing measure of food addiction performs in heterogeneous samples. In a cross-sectional survey design, using a diverse sample of undergraduate students (N = 642) tests of measurement invariance were performed. Confirmatory factor analysis supported the hypothesized factor structure, indicating a single latent construct of food addiction modeled by 11 dichotomous indicators, in samples of White and Black participants as well as samples of men and women. Measurement invariance testing across the various demographic groups broadly provided good psychometric support for use of the measure. However, a single indicator related to attempts to cut down on highly palatable food varied across men and women. Thus, when using the measure in mixed gender samples researchers may consider obtaining additional information regarding gender and its relative impact on the experience of food addiction, particularly with respect to efforts to quit or cut down intake of highly palatable foods. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Renormalization group, principle of invariance and functional automodelity

International Nuclear Information System (INIS)

Shirkov, D.V.

1981-01-01

There exists a remarkable identity of functional equations describing the property of functional automodelity in diverse branches of physics: renormalization group equations in quantum field theory, functional equations of the invariance principle of the one-dimensional transport theory and some others. The origin of this identity is investigated. It is shown that the structure of these equations reflects the simple and general property of transitivity with respect to the way of fixatio of initial on effective degrees of freedom [ru

Existence of a last invariant of conservative motion

International Nuclear Information System (INIS)

Hall, L.S.

1982-01-01

A general theory of integrable systems in two dimensions is formulated and applied. (The theory also has applications to more dimensions). The constraints are found which admit to general integrability of the orbits for magnetic forces as well as for forces derivable from a potential. When a system admits a given invariant, the invariant is found. A number of examples including known and apparently previously unknown invariants are given. The theory of exact integrals of the motion also can be extended to the derivation of approximate invariants. The general theory admits a variational principle, among other approximation techniques, for the computation of a best approximate invariant. The problem of the general cubic potential with one symmetric coordinate, V = 1/2 Ax 2 + 1/2 By 2 + Cx 2 y + 1/3 Dy 3 (of which the well-studied Henon-Heiles potential is the special case for A = B and C = -D), is examined in detail

Knot invariants derived from quandles and racks

OpenAIRE

Kamada, Seiichi

2002-01-01

The homology and cohomology of quandles and racks are used in knot theory: given a finite quandle and a cocycle, we can construct a knot invariant. This is a quick introductory survey to the invariants of knots derived from quandles and racks.

The Cross-Cultural Invariance of Creative Cognition: A Case Study of Creative Writing in U.S. and Russian College Students

Science.gov (United States)

Kornilov, Sergey A.; Kornilova, Tatiana V.; Grigorenko, Elena L.

2016-01-01

Unlike intelligence, creativity has rarely been investigated from the standpoint of cross-cultural invariance of the structure of the instruments used to measure it. In the study reported in this article, we investigated the cross-cultural invariance of expert ratings of creative stories written by undergraduate students from the Russian…

Invariant approach to CP in unbroken Δ(27

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Gustavo C. Branco

2015-10-01

Full Text Available The invariant approach is a powerful method for studying CP violation for specific Lagrangians. The method is particularly useful for dealing with discrete family symmetries. We focus on the CP properties of unbroken Δ(27 invariant Lagrangians with Yukawa-like terms, which proves to be a rich framework, with distinct aspects of CP, making it an ideal group to investigate with the invariant approach. We classify Lagrangians depending on the number of fields transforming as irreducible triplet representations of Δ(27. For each case, we construct CP-odd weak basis invariants and use them to discuss the respective CP properties. We find that CP violation is sensitive to the number and type of Δ(27 representations.

Joint survival probability via truncated invariant copula

International Nuclear Information System (INIS)

Kim, Jeong-Hoon; Ma, Yong-Ki; Park, Chan Yeol

2016-01-01

Highlights: • We have studied an issue of dependence structure between default intensities. • We use a multivariate shot noise intensity process, where jumps occur simultaneously and their sizes are correlated. • We obtain the joint survival probability of the integrated intensities by using a copula. • We apply our theoretical result to pricing basket default swap spread. - Abstract: Given an intensity-based credit risk model, this paper studies dependence structure between default intensities. To model this structure, we use a multivariate shot noise intensity process, where jumps occur simultaneously and their sizes are correlated. Through very lengthy algebra, we obtain explicitly the joint survival probability of the integrated intensities by using the truncated invariant Farlie–Gumbel–Morgenstern copula with exponential marginal distributions. We also apply our theoretical result to pricing basket default swap spreads. This result can provide a useful guide for credit risk management.

Invariance as a Tool for Ontology of Information

Directory of Open Access Journals (Sweden)

Marcin J. Schroeder

2016-03-01

Full Text Available Attempts to answer questions regarding the ontological status of information are frequently based on the assumption that information should be placed within an already existing framework of concepts of established ontological statuses related to science, in particular to physics. However, many concepts of physics have undetermined or questionable ontological foundations. We can look for a solution in the recognition of the fundamental role of invariance with respect to a change of reference frame and to other transformations as a criterion for objective existence. The importance of invariance (symmetry as a criterion for a primary ontological status can be identified in the methodology of physics from its beginnings in the work of Galileo, to modern classifications of elementary particles. Thus, the study of the invariance of the theoretical description of information is proposed as the first step towards ontology of information. With the exception of only a few works among publications which set the paradigm of information studies, the issues of invariance were neglected. Orthodox analysis of information lacks conceptual framework for the study of invariance. The present paper shows how invariance can be formalized for the definition of information and, accompanying it, mathematical formalism proposed by the author in his earlier publications.

Classification of compact homogeneous spaces with invariant G(2)-structures

Czech Academy of Sciences Publication Activity Database

Le, Hong-Van; Munir, M.

2012-01-01

Roč. 12, č. 2 (2012), s. 303-328 ISSN 1615-715X R&D Projects: GA AV ČR IAA100190701 Institutional support: RVO:67985840 Keywords : compact homogeneous space * G(2)-structure Subject RIV: BA - General Mathematics Impact factor: 0.371, year: 2012 http://www.degruyter.com/view/j/advg.2012.12.issue-2/advgeom.2011.054/advgeom.2011.054. xml

Slow feature analysis: unsupervised learning of invariances.

Science.gov (United States)

Wiskott, Laurenz; Sejnowski, Terrence J

2002-04-01

Invariant features of temporally varying signals are useful for analysis and classification. Slow feature analysis (SFA) is a new method for learning invariant or slowly varying features from a vectorial input signal. It is based on a nonlinear expansion of the input signal and application of principal component analysis to this expanded signal and its time derivative. It is guaranteed to find the optimal solution within a family of functions directly and can learn to extract a large number of decorrelated features, which are ordered by their degree of invariance. SFA can be applied hierarchically to process high-dimensional input signals and extract complex features. SFA is applied first to complex cell tuning properties based on simple cell output, including disparity and motion. Then more complicated input-output functions are learned by repeated application of SFA. Finally, a hierarchical network of SFA modules is presented as a simple model of the visual system. The same unstructured network can learn translation, size, rotation, contrast, or, to a lesser degree, illumination invariance for one-dimensional objects, depending on only the training stimulus. Surprisingly, only a few training objects suffice to achieve good generalization to new objects. The generated representation is suitable for object recognition. Performance degrades if the network is trained to learn multiple invariances simultaneously.

Renormalization-group-invariant 1/N corrections to nontrival φ4 theory

International Nuclear Information System (INIS)

Smekal, L.v.; Langfeld, K.; Reinhardt, H.; Langbein, R.F.

1994-01-01

In the framework of path integral linearization techniques, the effective potential and the master field equation for massless φ 4 theory, in the modified loop expansion around the mean field, are derived up to next to leading order. In the O(N)-symmetric theory, these equations are equivalent to a subsummation of O(N) and order 1 diagrams. A renormalization prescription is proposed which is manifestly renormalization group invariant. The numerical results for the potential in next to leading order agree qualitatively well with the leading order ones. In particular, the nontrivial phase structure remains unchanged. Quantitatively, the corrections ar small for N much-gt 8, but even for N as small as one their essential effect is to modify the scaling coefficient β 0 in the Callan-Symanzik β function, in accordance with conventional loop expansions. The numerical results are best parametrized by scaling improved mean field formulas. Dimensional transmutation renders the overall (physical) mass scale M 0 , generated by a dynamical breaking of scale invariance, the only adjustable parameter of the theory. Renormalization group invariance of the numerical results is explicitly verified

The Impact of Partial Measurement Invariance on Testing Moderation for Single and Multi-Level Data

Directory of Open Access Journals (Sweden)

Yu-Yu Hsiao

2018-05-01

Full Text Available Moderation effect is a commonly used concept in the field of social and behavioral science. Several studies regarding the implication of moderation effects have been done; however, little is known about how partial measurement invariance influences the properties of tests for moderation effects when categorical moderators were used. Additionally, whether the impact is the same across single and multilevel data is still unknown. Hence, the purpose of the present study is twofold: (a To investigate the performance of the moderation test in single-level studies when measurement invariance does not hold; (b To examine whether unique features of multilevel data, such as intraclass correlation (ICC and number of clusters, influence the effect of measurement non-invariance on the performance of tests for moderation. Simulation results indicated that falsely assuming measurement invariance lead to biased estimates, inflated Type I error rates, and more gain or more loss in power (depends on simulation conditions for the test of moderation effects. Such patterns were more salient as sample size and the number of non-invariant items increase for both single- and multi-level data. With multilevel data, the cluster size seemed to have a larger impact than the number of clusters when falsely assuming measurement invariance in the moderation estimation. ICC was trivially related to the moderation estimates. Overall, when testing moderation effects with categorical moderators, employing a model that accounts for the measurement (noninvariance structure of the predictor and/or the outcome is recommended.

Universal happiness? Cross-cultural measurement invariance of scales assessing positive mental health.

Science.gov (United States)

Bieda, Angela; Hirschfeld, Gerrit; Schönfeld, Pia; Brailovskaia, Julia; Zhang, Xiao Chi; Margraf, Jürgen

2017-04-01

Research into positive aspects of the psyche is growing as psychologists learn more about the protective role of positive processes in the development and course of mental disorders, and about their substantial role in promoting mental health. With increasing globalization, there is strong interest in studies examining positive constructs across cultures. To obtain valid cross-cultural comparisons, measurement invariance for the scales assessing positive constructs has to be established. The current study aims to assess the cross-cultural measurement invariance of questionnaires for 6 positive constructs: Social Support (Fydrich, Sommer, Tydecks, & Brähler, 2009), Happiness (Subjective Happiness Scale; Lyubomirsky & Lepper, 1999), Life Satisfaction (Diener, Emmons, Larsen, & Griffin, 1985), Positive Mental Health Scale (Lukat, Margraf, Lutz, van der Veld, & Becker, 2016), Optimism (revised Life Orientation Test [LOT-R]; Scheier, Carver, & Bridges, 1994) and Resilience (Schumacher, Leppert, Gunzelmann, Strauss, & Brähler, 2004). Participants included German (n = 4,453), Russian (n = 3,806), and Chinese (n = 12,524) university students. Confirmatory factor analyses and measurement invariance testing demonstrated at least partial strong measurement invariance for all scales except the LOT-R and Subjective Happiness Scale. The latent mean comparisons of the constructs indicated differences between national groups. Potential methodological and cultural explanations for the intergroup differences are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Finally! A valid test of configural invariance using permutation in multigroup CFA

NARCIS (Netherlands)

Jorgensen, T.D.; Kite, B.A.; Chen, P.-Y.; Short, S.D.; van der Ark, L.A.; Wiberg, M.; Culpepper, S.A.; Douglas, J.A.; Wang, W.-C.

2017-01-01

In multigroup factor analysis, configural measurement invariance is accepted as tenable when researchers either (a) fail to reject the null hypothesis of exact fit using a χ2 test or (b) conclude that a model fits approximately well enough, according to one or more alternative fit indices (AFIs).

Perturbation to Unified Symmetry and Adiabatic Invariants for Relativistic Hamilton Systems

International Nuclear Information System (INIS)

Zhang Mingjiang; Fang Jianhui; Lu Kai; Pang Ting; Lin Peng

2009-01-01

Based on the concept of adiabatic invariant, the perturbation to unified symmetry and adiabatic invariants for relativistic Hamilton systems are studied. The definition of the perturbation to unified symmetry for the system is presented, and the criterion of the perturbation to unified symmetry is given. Meanwhile, the Noether adiabatic invariants, the generalized Hojman adiabatic invariants, and the Mei adiabatic invariants for the perturbed system are obtained. (general)

Group-invariant solutions of nonlinear elastodynamic problems of plates and shells

International Nuclear Information System (INIS)

Dzhupanov, V.A.; Vassilev, V.M.; Dzhondzhorov, P.A.

1993-01-01

Plates and shells are basic structural components in nuclear reactors and their equipment. The prediction of the dynamic response of these components to fast transient loadings (e.g., loadings caused by earthquakes, missile impacts, etc.) is a quite important problem in the general context of the design, reliability and safety of nuclear power stations. Due to the extreme loading conditions a more adequate treatment of the foregoing problem should rest on a suitable nonlinear shell model, which would allow large deflections of the structures regarded to be taken into account. Such a model is provided in the nonlinear Donnell-Mushtari-Vlasov (DMV) theory. The governing system of equations of the DMV theory consists of two coupled nonlinear fourth order partial differential equations in three independent and two dependent variables. It is clear, as the case stands, that the obtaining solutions to this system directly, by using any of the general analytical or numerical techniques, would involve considerable difficulties. In the present paper, the invariance of the governing equations of DMV theory for plates and cylindrical shells relative to local Lie groups of local point transformations will be employed to get some advantages in connection with the aforementioned problem. First, the symmetry of a functional, corresponding to the governing equations of DMV theory for plates and cylindrical shells is studied. Next, the densities in the corresponding conservation laws are determined on the basis of Noether theorem. Finally, we study a class of invariant solutions of the governing equations. As is well known, group-invariant solutions are often intermediate asymptotics for a wider class of solutions of the corresponding equations. When such solutions are considered, the number of the independent variables can be reduced. For the class of invariant solutions studied here, the system of governing equations converts into a system of ordinary differential equations

Formulation of invariant functional integrals and applications to the quantization of gauge theories

International Nuclear Information System (INIS)

Botelho, L.C.L.

1985-01-01

Introducting a metrical structure into the Configuration Space of Quantum Field Theories with Infinite-Dimensional symetry group, a formulation of Invariant Functional Integrals suitable for their quantization, is obtained. It is apllied to Gauge Theories of Yang-Mills and Polyakov's Bosonic String; obtaining several new facts about them, as well as reproducing some well known results. By following the general idea of invariant functional measures; a fermionic (chiral) change of variables in the fermionic sector of two-dimensional massless Quantum-Chromodynamics is implemented obtaining by the first time, a pure gluonic effective action for the model. In adittion, the complete solution for the Rothe-Stamatesu Model, is obtained. (author) [pt

Examination of Measurement Invariance across Culture and Gender on the RCMAS-2 Short Form among Singapore and U.S. Adolescents

Science.gov (United States)

Lowe, Patricia A.; Ang, Rebecca P.

2016-01-01

Tests of measurement invariance were conducted across culture and gender on the Revised Children's Manifest Anxiety Scale-Second Edition (RCMAS-2) Short Form in a sample of 1,003 Singapore and U.S. adolescents. The results of multi-group confirmatory factor analyses across culture and gender supported at least partial measurement invariance. ANOVA…

Dark coupling and gauge invariance

International Nuclear Information System (INIS)

Gavela, M.B.; Honorez, L. Lopez; Mena, O.; Rigolin, S.

2010-01-01

We study a coupled dark energy-dark matter model in which the energy-momentum exchange is proportional to the Hubble expansion rate. The inclusion of its perturbation is required by gauge invariance. We derive the linear perturbation equations for the gauge invariant energy density contrast and velocity of the coupled fluids, and we determine the initial conditions. The latter turn out to be adiabatic for dark energy, when assuming adiabatic initial conditions for all the standard fluids. We perform a full Monte Carlo Markov Chain likelihood analysis of the model, using WMAP 7-year data

Dark Coupling and Gauge Invariance

CERN Document Server

Gavela, M B; Mena, O; Rigolin, S

2010-01-01

We study a coupled dark energy-dark matter model in which the energy-momentum exchange is proportional to the Hubble expansion rate. The inclusion of its perturbation is required by gauge invariance. We derive the linear perturbation equations for the gauge invariant energy density contrast and velocity of the coupled fluids, and we determine the initial conditions. The latter turn out to be adiabatic for dark energy, when assuming adiabatic initial conditions for all the standard fluids. We perform a full Monte Carlo Markov Chain likelihood analysis of the model, using WMAP 7-year data.

Original article Construct validity, dimensionality and factorial invariance of the Rosenberg Self-Esteem Scale: a bifactor modelling approach among children of prisoners

Directory of Open Access Journals (Sweden)

Kathryn Sharratt

2014-12-01

Full Text Available Background The Rosenberg Self-Esteem Scale (RSES has traditionally been conceptualised as a unidimensional measure of self-esteem, but empirical evidence is equivocal, with some studies supporting a one-factor solution and others favouring multidimensional models. Participants and procedure The aim of this study was to examine the factor structure, factorial invariance and composite reliability of the RSES within a European sample of children affected by parental imprisonment (N = 724. The study specified and tested six alternative factor models using conventional confirmatory factor analytic (CFA techniques and a confirmatory bifactor modelling approach. Results The RSES was most effectively represented by a bifactor model including a general self-esteem factor comprising all ten scale items and separate method effects for the positively and negatively phrased items. This model was found to be factorially invariant among boys and girls. Composite reliability indicated good internal consistency for the general self-esteem dimension but slightly less so for the positive and negative method effects. Conclusions It follows that the calculation of a total RSES score is appropriate for children of prisoners, providing that the presence of method effects is taken into consideration to avoid giving rise to false interpretations. This study demonstrated the application of a bifactorial modeling approach as a potential solution.

Spin foam diagrammatics and topological invariance

International Nuclear Information System (INIS)

Girelli, Florian; Oeckl, Robert; Perez, Alejandro

2002-01-01

We provide a simple proof of the topological invariance of the Turaev-Viro model (corresponding to simplicial 3D pure Euclidean gravity with cosmological constant) by means of a novel diagrammatic formulation of the state sum models for quantum BF theories. Moreover, we prove the invariance under more general conditions allowing the state sum to be defined on arbitrary cellular decompositions of the underlying manifold. Invariance is governed by a set of identities corresponding to local gluing and rearrangement of cells in the complex. Due to the fully algebraic nature of these identities our results extend to a vast class of quantum groups. The techniques introduced here could be relevant for investigating the scaling properties of non-topological state sums, proposed as models of quantum gravity in 4D, under refinement of the cellular decomposition

Second-order gauge-invariant perturbations during inflation

International Nuclear Information System (INIS)

Finelli, F.; Marozzi, G.; Vacca, G. P.; Venturi, G.

2006-01-01

The evolution of gauge invariant second-order scalar perturbations in a general single field inflationary scenario are presented. Different second-order gauge-invariant expressions for the curvature are considered. We evaluate perturbatively one of these second order curvature fluctuations and a second-order gauge-invariant scalar field fluctuation during the slow-roll stage of a massive chaotic inflationary scenario, taking into account the deviation from a pure de Sitter evolution and considering only the contribution of super-Hubble perturbations in mode-mode coupling. The spectra resulting from their contribution to the second order quantum correlation function are nearly scale-invariant, with additional logarithmic corrections with respect to the first order spectrum. For all scales of interest the amplitude of these spectra depends on the total number of e-folds. We find, on comparing first and second order perturbation results, an upper limit to the total number of e-folds beyond which the two orders are comparable

Field transformations, collective coordinates and BRST invariance

International Nuclear Information System (INIS)

Alfaro, J.; Damgaard, P.H.

1989-12-01

A very large class of general field transformations can be viewed as a field theory generalization of the method of collective coordinates. The introduction of new variables induces a gauge invariance in the transformed theory, and the freedom left in gauge fixing this new invariance can be used to find equivalent formulations of the same theory. First the Batalin-Fradkin-Vilkovisky formalism is applied to the Hamiltonian formulation of physical systems that can be described in terms of collective coordinates. We then show how this type of collective coordinate scheme can be generalized to field transformations, and discuss the War Identities of the associated BRST invariance. For Yang-Mills theory a connection to topological field theory and the background field method is explained in detail. In general the resulting BRST invariance we find hidden in any quantum field theory can be viewed as a consequence of our freedom in choosing a basis of coordinates φ(χ) in the action S[φ]. (orig.)

Modified dispersion relations, inflation, and scale invariance

Science.gov (United States)

Bianco, Stefano; Friedhoff, Victor Nicolai; Wilson-Ewing, Edward

2018-02-01

For a certain type of modified dispersion relations, the vacuum quantum state for very short wavelength cosmological perturbations is scale-invariant and it has been suggested that this may be the source of the scale-invariance observed in the temperature anisotropies in the cosmic microwave background. We point out that for this scenario to be possible, it is necessary to redshift these short wavelength modes to cosmological scales in such a way that the scale-invariance is not lost. This requires nontrivial background dynamics before the onset of standard radiation-dominated cosmology; we demonstrate that one possible solution is inflation with a sufficiently large Hubble rate, for this slow roll is not necessary. In addition, we also show that if the slow-roll condition is added to inflation with a large Hubble rate, then for any power law modified dispersion relation quantum vacuum fluctuations become nearly scale-invariant when they exit the Hubble radius.

Approaches to linear local gauge-invariant observables in inflationary cosmologies

Czech Academy of Sciences Publication Activity Database

Fröb, M. B.; Hack, T.-P.; Khavkine, Igor

2018-01-01

Roč. 35, č. 11 (2018), č. článku 115002. ISSN 0264-9381 R&D Projects: GA ČR(CZ) GA18-07776S Institutional support: RVO:67985840 Keywords : Gauge-invariant observables * cosmological perturbations * single field inflation Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 3.119, year: 2016 http://iopscience.iop.org/article/10.1088/1361-6382/aabcb7/meta

Measurement Invariance of the Short Version of the Problematic Mobile Phone Use Questionnaire (PMPUQ-SV) across Eight Languages.

Science.gov (United States)

Lopez-Fernandez, Olatz; Kuss, Daria J; Pontes, Halley M; Griffiths, Mark D; Dawes, Christopher; Justice, Lucy V; Männikkö, Niko; Kääriäinen, Maria; Rumpf, Hans-Jürgen; Bischof, Anja; Gässler, Ann-Kathrin; Romo, Lucia; Kern, Laurence; Morvan, Yannick; Rousseau, Amélie; Graziani, Pierluigi; Demetrovics, Zsolt; Király, Orsolya; Schimmenti, Adriano; Passanisi, Alessia; Lelonek-Kuleta, Bernadeta; Chwaszcz, Joanna; Chóliz, Mariano; Zacarés, Juan José; Serra, Emilia; Dufour, Magali; Rochat, Lucien; Zullino, Daniele; Achab, Sophia; Landrø, Nils Inge; Suryani, Eva; Hormes, Julia M; Terashima, Javier Ponce; Billieux, Joël

2018-06-08

The prevalence of mobile phone use across the world has increased greatly over the past two decades. Problematic Mobile Phone Use (PMPU) has been studied in relation to public health and comprises various behaviours, including dangerous, prohibited, and dependent use. These types of problematic mobile phone behaviours are typically assessed with the short version of the Problematic Mobile Phone Use Questionnaire (PMPUQ⁻SV). However, to date, no study has ever examined the degree to which the PMPU scale assesses the same construct across different languages. The aims of the present study were to (i) determine an optimal factor structure for the PMPUQ⁻SV among university populations using eight versions of the scale (i.e., French, German, Hungarian, English, Finnish, Italian, Polish, and Spanish); and (ii) simultaneously examine the measurement invariance (MI) of the PMPUQ⁻SV across all languages. The whole study sample comprised 3038 participants. Descriptive statistics, correlations, and Cronbach's alpha coefficients were extracted from the demographic and PMPUQ-SV items. Individual and multigroup confirmatory factor analyses alongside MI analyses were conducted. Results showed a similar pattern of PMPU across the translated scales. A three-factor model of the PMPUQ-SV fitted the data well and presented with good psychometric properties. Six languages were validated independently, and five were compared via measurement invariance for future cross-cultural comparisons. The present paper contributes to the assessment of problematic mobile phone use because it is the first study to provide a cross-cultural psychometric analysis of the PMPUQ-SV.

Real-time trajectory analysis using stacked invariance methods

OpenAIRE

Kitts, B.

1998-01-01

Invariance methods are used widely in pattern recognition as a preprocessing stage before algorithms such as neural networks are applied to the problem. A pattern recognition system has to be able to recognise objects invariant to scale, translation, and rotation. Presumably the human eye implements some of these preprocessing transforms in making sense of incoming stimuli, for example, placing signals onto a log scale. This paper surveys many of the commonly used invariance methods, and asse...

Invariant subsets under compact quantum group actions

OpenAIRE

Huang, Huichi

2012-01-01

We investigate compact quantum group actions on unital $C^*$-algebras by analyzing invariant subsets and invariant states. In particular, we come up with the concept of compact quantum group orbits and use it to show that countable compact metrizable spaces with infinitely many points are not quantum homogeneous spaces.

Borromean surgery formula for the Casson invariant

DEFF Research Database (Denmark)

Meilhan, Jean-Baptiste Odet Thierry

2008-01-01

It is known that every oriented integral homology 3-sphere can be obtained from S3 by a finite sequence of Borromean surgeries. We give an explicit formula for the variation of the Casson invariant under such a surgery move. The formula involves simple classical invariants, namely the framing...

Translationally invariant and non-translationally invariant empirical effective interactions

International Nuclear Information System (INIS)

Golin, M.; Zamick, L.

1975-01-01

In this work empirical deficiencies of the core-renormalized realistic effective interactions are examined and simple corrective potentials are sought. The inability of the current realistic interactions to account for the energies of isobaric analog states is noted, likewise they are unable to reproduce the changes in the single-particle energies, as one goes from one closed shell to another. It is noted that the Schiffer interaction gives better results for these gross properties and this is attributed to a combination of several facts. First, to the inclusion of long range terms in the Schiffer potential, then to the presence of relative p-state terms (l=1), in addition to the usual relative s-state terms (l=0). The strange shape of the above interaction is further attributed to the fact that it is translationally invariant whereas the theory of core-polarization yields non-translationally invariant potentials. Consequently, as a correction to the monopole deficiencies of the realistic interactions the term Vsub(mon)=ar 2 (1)r 2 (2)+r 2 (1)+β[r 4 (1)r 2 (2)r 4 (2) ] is proposed. (Auth.)