Revistas académicas de la Universidad Católica del Norte
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Branch duplication in trees: uniqueness of seeds and enumeration of seeds
No full textBy the process of branch duplication, any tree may be generated from a type of tree called a seed. We describe the correspondence between trees and seeds by showing that each tree grows from a unique seed and giving an algorithm to produce this seed. Using results about the structure of seeds, we enumerate the seeds of a given diameter
Zk-magic labeling of star of graphs
No full textFor any non-trivial abelian group A under addition a graph G is said to be A-magic if there exists a labeling f : E(G) → A − {0} such that, the vertex labeling f + defined as f +(v) = Pf(uv) taken over all edges uv incident at v is a constant. An A-magic graph G is said to be Zk-magic graph if the group A is Zk, the group of integers modulo k and these graphs are referred to as k-magic graphs. In this paper we prove that the graphs such as star of cycle, flower, double wheel, shell, cylinder, gear, generalised Jahangir, lotus inside a circle, wheel, closed helm graph are Zk-magic graphs
Edge irregularity strength of certain families of comb graph
No full textEdge irregular mapping or vertex mapping h : V (U ) −→ {1, 2, 3, 4, ..., s} is a mapping of vertices in such a way that all edges have distinct weights. We evaluate weight of any edge by using equation wth(cd) = h(c)+h(d), ∀c, d ∈ V (U ) and ∀cd ∈ E(U ). Edge irregularity strength denoted by es(U ) is a minimum positive integer use to label vertices to form edge irregular labeling. In this paper, we find exact value of edge irregularity strength of different families of comb graph
Topological properties of four types of porphyrin dendrimers
No full textA chemical compound can be represented as a chemical graph. A topological index of a (chemical) graph is a numeric value of a graph which characterize its topology and is usually graph invariant. The Zagreb indices, Randić index and sum-connectivity indices are useful in the study of anti-inflammatory activities, boiling point, molecular complexity heterosystems of certain chemical instances, and in elsewhere. In this paper, we calculate the mentioned topological indices of some infinite classes of prophyrin dendrimers
Cognitive test anxiety scale: Propriedades psicométricas no contexto brasileiro
Get PDFPrevious: Cognitive anxiety refers to excessive worries before, during and after of the tests, interfering in the performance and causing academic failure, and is positively associated with neuroticism and depression. Objective: The objective was to gather evidence of psychometric quality of the Cognitive Test Anxiety Scale (CTAS) in Brazil. Method: Two studies were conducted: In study 1, 210 university students from the city of Parnaíba, Piauí, Brazil (Average age = 21.7; SD = 3.73) participated, most of them studying Psychology (60%) and women (58.6%). They answered CTAS and demographic questions. An exploratory factor analysis suggested a one-dimensional solution that explained 46.94% of the total variance of the items. Reliability was evaluated by Cronbach's alpha (?) and McDonald's omega (?) indicators equal to .92. In Study 2, 274 university students from different Brazilian regions participated (Average age = 21.7; SD = 3.73), most of the state of Piauí (60%), studying Psychology (60.4%). A confirmatory factor analysis indicated adequate indicators (CFI = .96; TLI = .95; RMSEA = .06). The reliability was satisfactory: (?) and (?) equal to .94. Conclusion: Psychometric evidence was found for Brazil, and CTAS may be useful for those interested in investigating the theme and its correlates.Antecedentes: La ansiedad cognitiva se refiere a preocupaciones excesivas antes, durante y después a los exámenes, que interfieren con el rendimiento y causan fracaso académico, y se asocia positivamente con el neuroticismo y la depresión. Objetivo: El objetivo fue reunir evidencia de la calidad psicométrica de la Cognitive Test Anxiety Scale (CTAS) en Brasil. Método: Se realizaron dos estudios: en el estudio 1, participaron 210 estudiantes universitarios de la ciudad de Parnaíba, Piauí, Brasil (Medad = 21.7; SD = 3.73), la mayoría de ellos estudiando Psicología (60%) y mujeres (58.6%). Respondieron a la CTAS y a preguntas demográficas. El análisis factorial exploratorio sugirió una solución unidimensional, que explicaba el 46.94% de la varianza total de los ítems. La fiabilidad se evaluó mediante los indicadores alfa de Cronbach (α) y omega de McDonald (ω) iguales a 0.92. En el Estudio 2, participaron 274 estudiantes universitarios de diferentes regiones brasileñas (Medad = 21.7; SD = 3.73), la mayoría del estado de Piauí (60%), estudiando Psicología (60.4%). Un análisis factorial confirmatorio apuntó indicadores adecuados (CFI = 0.96; TLI = 0.95; RMSEA = 0.06). La fiabilidad fue satisfactoria: (α) y (ω) iguales a 0,94. Conclusión: Se encontró evidencia psicométrica para Brasil, y CTAS puede ser útil para aquellos interesados en investigar el tema y sus correlatos.Antecendentes: A ansiedade cognitiva refere-se a preocupações excessivas, antes, durante e depois das avaliações, interferindo no desempenho e ocasionando o fracasso acadêmico, além de estar associada positivamente o com neuroticismo e a depressão.
Objetivou:Objetivou-se reunir evidências de qualidade psicométrica da Cognitive Test Anxiety Scale(CTAS) no Brasil. Método: Foram realizadosdois estudos: No estudo 1 participaram 210 universitários da cidade de Parnaíba, Piauí, Brasil (Medade=21,7; DP=3,73), a maioriacursando Psicologia (60%) e mulheres (58,6%).Responderam a CTAS e questões demográficas. RESULTADOS: A análise fatorialexploratória sugeriu uma solução unidimensional, que explicou 46,94% da variância total dos itens. A confiabilidade foi avaliada pelosindicadores alfa de Cronbach (α) e ômega de McDonald (ω) iguais a 0,92. No Estudo 2, participaram 274 universitários de diferentesregiões brasileiras (Miedad=21,7; DP=3,73), a maioria do estado do Piauí (60%), cursando Psicologia (60,4%). Uma análise fatorialconfirmatória apontou indicadores adequados (CFI=0,96; TLI=0,95; RMSEA=0,06). A confiabilidade foi satisfatória: (α) e (ω) iguais a0,94.
Conclusão: Foram encontradas evidências psicométricas para o Brasil, podendo a CTAS serútil para interessados em investigar a temática e seus correlatos
Discussion on relation-theoretic for JS-quasi-contractions of uni/milti-dimensional mappings with transitivity
No full textWe introduce the notion of a JSR quasi-contraction mapping, where R is a binary relation on its domain. Also, we prove some fixed point results for such contractions in complete metric spaces endowed with a transitive relation. An example is given to substantiate our obtained theorems. In addition, we introduce a JSRN -quasicontraction and also establish fixed point of N-order theorems for such contractions
Fuzzy δ∗-almost continuous and fuzzy δ∗-continuous functions in mixed fuzzy ideal topological spaces
No full textIn this paper we introduce two new classes of functions between mixed fuzzy topological spaces, namely fuzzy δ∗-almost continuous and fuzzy δ∗-continuous functions and investigate some of their properties.
The description of these two types of functions facilitated by the introduction of generalized open sets, called fuzzy δ-preopen sets, fuzzy δ-precluster point, fuzzy preopen sets, fuzzy δ-pre-q-neighbourhoods
Non-linear new product A*B-B*A derivations on *-algebras
No full textLet A be a prime ∗-algebra with unit I and a nontrivial projection. Then the map Φ : A → A satisfies in the following condition
Φ(A ⋄ B) = Φ(A) ⋄ B + A ⋄ Φ(B)
where A⋄ B = A∗B −B∗A for all A, B ∈ A, is additive. Moreover, if Φ(αI) is self-adjoint operator for α ∈ {1, i} then Φ is a ∗-derivation
The essential norm of multiplication operators acting on Orlicz sequence spaces
No full textWe calculate the measure of non-compactness or the essential norm of the multiplication operator Mu acting on Orlicz sequence spaces lϕ. As a consequence of our result, we obtain a known criteria for the compactness of multiplication operator acting on lϕ
Caracterizaciones adicionales de la propiedad y algunas aplicaciones
No full textWe carry out characterizations with techniques provided by the local spectral theory of bounded linear operators T L(X), X infinite dimensional complex Banach space, which verify property (V-sub Pi) introduced by Sanabria et al. (Open Math. 16(1) (2018), 289-297). We also carry out the study for polaroid operators and Drazin invertible operators that verify the property mentioned above