Search results for "Correlation"
showing 10 items of 2282 documents
Lock-In Signal Post-Processing Techniques in Infra-Red Thermography for Materials Structural Evaluation
2013
This paper describes the potential of off-line thermographic signal processing by means of Lock-In Correlation algorithms, in order to implement structural health monitoring and stress analysis techniques. Thermal datasets acquired by infrared thermocameras are locked-in and correlated numerically with opportune reference signals, and amplitude and phase values of various harmonics retrieved by means of a Fast Fourier Transform and time averaging based filtering. This information is then processed for NDT defect probing and for evaluating the Thermoelastic Effect induced temperature changes. Two case studies in particular are discussed, implementing the proposed signal lock-in processing: a…
Nonlinear morphological correlation: optoelectronic implementation
2008
An optoelectronic implementation of the nonlinear morphological correlation by use of a threshold-decomposition technique and a joint transform correlator architecture is presented. This nonlinear morphological correlation provides improved image detection compared with standard linear optical pattern-recognition correlation methods. It also offers a more robust detection of low-intensity images in the presence of high-intensity patterns to be rejected.
Three-dimensional dynamic light scattering
1999
Abstract We describe the employment of a novel light-scattering scheme for the decorrelation of multiple scattering in strongly turbid samples. The three-dimensional scheme, which has been proposed already theoretically, shows certain advantages compared with the two-colour apparatus, which is commercially available. We describe our set-up in detail; features are the use of modern semiconductor laser diodes and contemporary single-mode fibre receivers. We show experimentally that the optimal signal-to-noise ratio (or intercept) β opt = 0.20, which is obtainable with our set-up, can be quantitatively calculated from the measured uncertainties in the alignment. In particular, we give a detail…
Qualitative and quantitative characterization of the in vitro dehydration process of hydrogel contact lenses
2007
Purpose: To investigate the in vitro dehydration process of conventional hydrogel and silicone-hydrogel contact lens materials. Methods: Eight conventional hydrogel and five silicone-hydrogel contact lenses were dehydrated under controlled environmental conditions on an analytical balance. Data were taken at 1-min intervals and dehydration curves of cumulative dehydration (CD), valid dehydration (VD), and dehydration rate (DR) were obtained. Several quantitative descriptors of the dehydration process were obtained by further processing of the information. Results: Duration of phase I (r 2 5 0.921), CD at end of phase I (r 2 5 0.971), time to achieve a DR of � 1%/min (r 2 5 0.946) were stron…
Rational-experiential thinking style and rational intergroup cooperation: the moderating role of intergroup conflict / Estilos de pensamiento raciona…
2016
AbstractCooperative relationships between groups are difficult because of the high human capability to differentiate between in-group vs. out-group members. This obstacle exists even when the groups can obtain benefits for themselves from cooperation with other groups (rational cooperation). Based on an interactionist approach, the authors propose that personal (individual differences) and situational (conflicts) factors contribute to rational intergroup cooperation. The authors conducted a preliminary correlational study (Study 1) and an experimental investigation (Study 2). In Study 1, the authors examined, with 105 participants, the psychometric properties of the Spanish version of the R…
The relationship between positive and negative affect in the Positive and Negative Affect Schedule
2002
Abstract The Positive and Negative Affect Schedule (PANAS; Watson, Clark, & Tellegen, 1988 ) is one of the most widely used affect scales. Nevertheless, the relation between its two scales, positive affect (PA) and negative affect (NA), is still controversial. Previous results that suggest independence between NA and PA were limited to manifest variables. In this study, the relation between PA and NA for both state and trait instructions was analyzed by means of structural equation modeling. Two hundred ninety-two participants responded to the PANAS at three occasions of measurement. No association was found between trait PA and NA, but significant negative correlations between state PA and…
The correlation between right-wing authoritarianism and social dominance orientation: The moderating effects of political and religious identity
2008
In a secondary analysis performed on a representative sample of the Italian population (N = 887), we examined the correlation between right-wing authoritarianism (RWA) and social dominance orientation (SDO), analyzing the moderating effect exerted on such correlation by political interest and religion importance. RWA and SDO showed a positive, significant correlation (r = .38), moderated by political interest (which heightened it) and religion importance (which lowered it). Limits, implications, and possible developments of the research are discussed.
Correlations among Game of Thieves and other centrality measures in complex networks
2021
Social Network Analysis (SNA) is used to study the exchange of resources among individuals, groups, or organizations. The role of individuals or connections in a network is described by a set of centrality metrics which represent one of the most important results of SNA. Degree, closeness, betweenness and clustering coefficient are the most used centrality measures. Their use is, however, severely hampered by their computation cost. This issue can be overcome by an algorithm called Game of Thieves (GoT). Thanks to this new algorithm, we can compute the importance of all elements in a network (i.e. vertices and edges), compared to the total number of vertices. This calculation is done not in…
Cross-lagged associations between problem behaviors and teacher-student relationships in early adolescence
2017
This study investigated the cross-lagged associations between teacher-student relationships and problem behaviors in a sample of 440 Finnish students (half of them identified as being at risk of reading difficulties). The degree to which these associations were moderated by a child’s gender, academic performance, risk for reading difficulties, parental education, and having the same teacher over 2 years was examined. The teachers evaluated the students’ problem behaviors and reported closeness and conflict with a particular student. The results showed that the higher the students scored on externalizing problems in Grade 4, the more conflict teachers reported 2 years later. Moderator analy…
Explaining Method Effects Associated With Negatively Worded Items in Trait and State Global and Domain-Specific Self-Esteem Scales
2013
Several investigators have interpreted method effects associated with negatively worded items in a substantive way. This research extends those studies in different ways: (a) it establishes the presence of methods effects in further populations and particular scales, and (b) it examines the possible relations between a method factor associated with negatively worded items and several covariates. Two samples were assessed: 592 high school students from Valencia (Spain), and 285 batterers from the same city. The self-esteem scales used were Rosenberg's Self-Esteem Scale, the State Self-Esteem Scale, and Self-Esteem 17. Anxiety was also assessed with the State-Trait Anxiety Inventory, and gend…