scholarly journals A vertex similarity index for better personalized recommendation

2017 ◽  
Vol 466 ◽  
pp. 607-615 ◽  
Author(s):  
Ling-Jiao Chen ◽  
Zi-Ke Zhang ◽  
Jin-Hu Liu ◽  
Jian Gao ◽  
Tao Zhou
Keyword(s):  
Similarity Index ◽  
Personalized Recommendation ◽  
Vertex Similarity

scholarly journals DEGREE CORRELATION OF BIPARTITE NETWORK ON PERSONALIZED RECOMMENDATION

2010 ◽  
Vol 21 (01) ◽  
pp. 137-147 ◽  
Author(s):  
JIAN-GUO LIU ◽  
TAO ZHOU ◽  
BING-HONG WANG ◽  
YI-CHENG ZHANG ◽  
QIANG GUO
Keyword(s):  
Hamming Distance ◽  
Similarity Index ◽  
Product Distribution ◽  
Personalized Recommendation ◽  
Bipartite Network ◽  
Recommendation Algorithm ◽  
Data Set ◽  
Statistical Property ◽  
Degree Correlation ◽  
Ranking Score

In this paper, the statistical property, namely degree correlation between users and objects, is taken into account and be embedded into the similarity index of collaborative filtering (CF) algorithm to improve the algorithmic performance. The numerical simulation on a benchmark data set shows that the algorithmic accuracy of the presented algorithm, measured by the average ranking score, is improved by 18.19% in the optimal case. The statistical analysis on the product distribution of the user and object degrees indicate that, in the optimal case, the distribution obeys the power-law and the exponential is equal to -2.33. Numerical results show that the presented algorithm can provide more diverse and less popular recommendations, for example, when the recommendation list contains 10 objects, the diversity, measured by the hamming distance, is improved by 21.90%. Since all of the real recommendation data evolving with time, this work may shed some light on the adaptive recommendation algorithm which could change its parameter automatically according to the statistical properties of the user-object bipartite network.

A Test of Three Sadism Measures

2020 ◽  
Vol 41 (4) ◽  
pp. 219-227 ◽  
Author(s):  
Bojana M. Dinić ◽  
Tara Bulut Allred ◽  
Boban Petrović ◽  
Anja Wertag
Keyword(s):  
Item Response ◽  
Social Groups ◽  
Similarity Index ◽  
Dark Triad ◽  
Hierarchical Regression ◽  
Fit Indices ◽  
Profile Similarity ◽  
Positive Attitudes ◽  
Confirmatory Factor ◽  
Positive Correlations

Abstract. The aim of this study was to evaluate psychometric properties of three sadism scales: Short Sadistic Impulse Scale (SSIS), Varieties of Sadistic Tendencies (VAST, which measures direct and vicarious sadism), and Assessment of Sadistic Personality (ASP). Sample included 443 participants (50.1% men) from the general population. Reliability based on internal consistency of all scales was good, and results of Confirmatory Factor Analysis (CFA) showed that all three scales had acceptable fit indices for the proposed structure. Results of Item Response Theory (IRT) analysis showed that all three scales had higher measurement precision (information) in above-average scores. Validity of the scales was supported through moderate to high positive correlations with the Dark Triad traits, especially psychopathy, as well as positive correlations with aggressiveness and negative with Honesty-Humility. Moreover, results of hierarchical regression analysis showed that all three measures of direct, but not vicarious sadism, contributed significantly above and beyond other Dark Triad traits to the prediction of increased positive attitudes toward dangerous social groups. The profile similarity index showed that the SSIS and the ASP were highly overlapping, while vicarious sadism seems distinct from other sadism scales.

Carabidae of Barnaul city parks: ecological characteristics and species composition

2018 ◽  
Vol 8 (2) ◽  
pp. 348-353
Author(s):  
E. A. Kuchina ◽  
N. D. Ovcharenko ◽  
L. D. Vasileva
Keyword(s):  
Species Composition ◽  
Diversity Index ◽  
Similarity Index ◽  
Life Forms ◽  
Ground Beetles ◽  
Forest Steppe ◽  
Ecological Groups ◽  
Dominant Group ◽  
Species Diversity Index ◽  
Steppe Species

<p>Anthropogenic impact on the population of ground beetles leads to a change in their numbers, structure of dominance, density, species composition, spectrum of life forms. This makes the beetles Carabidae a convenient and informative bioindicator of the ecological state of biocenoses. The material for this work was the Carabidae collections conducted in June-August 2016-2017 in the park zone of different regions of Barnaul, differing in location, area, hydrological regime, vegetation cover, purpose and anthropogenic load. When processing the material, the quantitative, species and generic composition of the carabidae was determined, calculations were made for such indicators as the Berger-Parker dominance index, the Shannon species diversity index (Hs), and the Jacquard species similarity index. The fauna (Coleoptera, Carabidae) of the park zone of Barnaul is represented by 55 species belonging to 20 genera. The dominant group is represented by species belonging to steppe, forest and polyzonal groups. Forest-steppe species of ground beetles as dominants have not been identified in any of the investigated territories. The greatest variety of ecological groups was noted on the territory of the Yubileyny рark, which is explained by the presence of zones with various microclimatic conditions, the presence of a birch grove that flows through the park with the Pivovarka River, and a wide log in the park. Registered species belong to eight groups of life forms belonging to two classes - zoophagous and myxophytophagous. On the numerical and species abundance, zoophages predominate. The spectrum of life forms corresponds to the zonal spectrum characteristic of the forest-steppe zone.</p><p> </p>

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