Search results for "correlation analysis"
showing 10 items of 75 documents
A Lotka-type model for oscillations in surface reactions
1997
In this paper we introduce a reaction model on a lattice which leads to oscillations. The model consists of two monomolecular and one bimolecular reaction step and is related to the Lotka model. Despite the simple evolution rules, the model shows a complex behaviour (i.e. the appearance of oscillations). This offers us the opportunity to test different types of stochastic approximations and compare them with the results of a Monte Carlo simulation. The simulation is performed on a large lattice (L = 1024) in order to take long-range correlations into account. Comparing the results of this simulation with the stochastic approaches shows that only advanced numerical approximations are able to…
Why the Universe is not a fractal
1990
L'etude du survey des redshifts CfA montre que la distribution des galaxies dans l'Univers obeit a une loi d'echelle sur des echelles de longueur inferieures a environ 5 h −1 Mpc. Cependant, l'Univers n'est pas bien represente par une fractale homogene sur ces echelles. La dependance de la longueur de correlation avec la profondeur des echantillons et la luminosite est etudiee. Une methode basee sur l'arbre maximal est presentee pour determiner la dimension de Hausdorff d'une distribution de points. Cette technique est ensuite appliquee au catalogue CfA
Gingival hyperplasia as an early manifestation of acute myeloid leukemia. A retrospective review
2019
Background We study the prevalence of acute myeloid leukemia (AML) among patients with severe gingival enlargement. Material and Methods We retrospective reviewed the clinical records of patients with severe gingival enlargement, between 2011 and 2018. The Saxer and Mühlemann index were used to measure inflammation and gingival bleeding. The degree of dental mobility was measured by the Nyman and Lindhe technique. Results A correlation analysis was carried out to test whether there were any associations among the different variables. In the sample of 117 patients the mean gingival bleeding index was ≥3 and the degree of dental mobility ≥2.3. 1.7% of patients, with severe gingival hyperplasi…
The Influence of Sales Stimulation Methods on the Behaviour of Consumers While Making the Decision on Purchase of Products in the Latvian Market
2018
The purpose of this research is the determination the extent of influence of various stimulation methods on the behaviour of consumers while making the decision on purchase of products in the Latvian market. In the course of the research approaches to development and realization of sales’ stimulation process were used which were described in scientific literature and the results of empirical researches that were made under the leadership of the authors. In the article the following research methods were used: abstract literature analysis, Latvian residents’ questionnaire (1320 respondents), and the correlation analysis. As a result the model for developing and realization of sales promotion…
THE IMPACT OF FAMILY AND INDIVIDUAL FACTORS ON 4TH GRADE STUDENTS’ SELF-CONFIDENCE IN READING LITERACY: RESULTS FROM PIRLS 2016
2021
The self-confidence of a child and an adult is associated with performance and achievement results. It is well-studied, and the correlation has been proved that higher self-efficacy leads to higher achievements and performance, including better performance in reading literacy. It is also known that both a family and a home environment have a tremendous impact on the child’s development and academic performance. This article focuses on the 4 th graders and their family factor impact on the development of a child’s self-confidence and concepts related to self-confidence. The purpose of this article is to define concepts that are closely related to self-confidence and to identify family factor…
Analysis and assessment of trace element contamination in offshore sediments of the Augusta Bay (SE Sicily): A multivariate statistical approach base…
2014
Abstract An application of multivariate statistical methods is provided to identify anthropogenic contaminants and lithogenic elements in offshore sediments collected near the heavily industrialized Augusta Bay, Sicily. An exploratory statistical technique, based on canonical correlation analysis (CCA) and mixture density estimation approach, is used for distinguishing between natural and anthropogenic contributions of trace elements in the investigated sediments. Following the intensive industrialization of Augusta area, marine sediments reveal the severe impact of local anthropogenic activities for many elements (e.g. As, Cd, Hg, Pb, and Sb), which are considered very dangerous for the en…
The Western Space Policies under the Influence of International Factors: Mutuality of Russia’s Case
2015
The research is dedicated to the problem of mutual dependence in space policies between the West, represented by great spacefaring actors the US and the EU, and Russia. In the study the correlation analysis, content analysis, and scenario-building methods were used. The conclusion of the analysis comprises consideration on the need to invest in their independence by Western countries in order to avoid unnecessary extra dependence on uncertain and unreliable regimes that supply substantial components for their space technology.
Analysing Student Performance using Sparse Data of Core Bachelor Courses
2015
Curricula for Computer Science (CS) degrees are characterized by the strong occupational orientation of the discipline. In the BSc degree structure, with clearly separate CS core studies, the learning skills for these and other required courses may vary a lot, which is shown in students' overall performance. To analyze this situation, we apply nonstandard educational data mining techniques on a preprocessed log file of the passed courses. The joint variation in the course grades is studied through correlation analysis while intrinsic groups of students are created and analyzed using a robust clustering technique. Since not all students attended all courses, there is a nonstructured sparsity…
Dynamic aphasia and the generation of language
2004
Severely reduced propositional speech in the context of intact nominal language skills (i.e., repetition, naming, comprehension, and reading) is the hallmark of dynamic aphasia (Luria, 1970). Recent evidence suggests there may be different types of dynamic aphasia as some patients do not produce any response on verbal generation tasks, whilst others are able to perform normally on verbal genera- tion tasks. For example, Robinson and colleagues (Robinson, Blair, & Cipolotti, 1998; Robinson, Shallice, & Cipolotti, 2004) reported two dynamic aphasics who failed to produce a verbal response when many verbal response options were activated by a stimulus, but not when a dominant response was avai…
Predictores cognitivos de la intención de práctica y la percepción de las relaciones en el deporte: análisis de la pasión como mediadora (Cognitive p…
2019
Este estudio analizó el papel de la inteligencia en el juego y la motivación como predictores de la intención de práctica deportiva y las relaciones sociales. Asimismo examina el papel de la motivación autodeterminada y la pasión (armoniosa y obsesiva) como mediadoras de esta relación, incorporando la percepción de conflicto. Participaron 180 jugadores adolescentes de fútbol, baloncesto y balonmano, de ambos géneros (124 chicos y 56 chicas) y de edades comprendidas entre 15 y 19 años (M= 15,9; S= 1,029). Se llevó a cabo un análisis correlacional y análisis SEM (Structural Equation Modeling) de dos modelos estructurales, uno con la pasión armoniosa y otro con la pasión obsesiva. El ajuste de…