A General Weighted Two-Way Dissimilarity Coefficient

2000 ◽  
Vol 17 (1) ◽  
pp. 101-121 ◽  
Author(s):  
Trevor F. Cox ◽  
Michael A. A. Cox
Keyword(s):  
Dissimilarity Coefficient

scholarly journals Weighted k-Prototypes Clustering Algorithm Based on the Hybrid Dissimilarity Coefficient

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ziqi Jia ◽  
Ling Song
Keyword(s):  
Categorical Data ◽  
Clustering Algorithm ◽  
Numerical Data ◽  
Experimental Results ◽  
Cluster Center ◽  
Real Dataset ◽  
Dissimilarity Coefficient ◽  
Initial Cluster ◽  
Data Objects ◽  
Selection Of

The k-prototypes algorithm is a hybrid clustering algorithm that can process Categorical Data and Numerical Data. In this study, the method of initial Cluster Center selection was improved and a new Hybrid Dissimilarity Coefficient was proposed. Based on the proposed Hybrid Dissimilarity Coefficient, a weighted k-prototype clustering algorithm based on the hybrid dissimilarity coefficient was proposed (WKPCA). The proposed WKPCA algorithm not only improves the selection of initial Cluster Centers, but also puts a new method to calculate the dissimilarity between data objects and Cluster Centers. The real dataset of UCI was used to test the WKPCA algorithm. Experimental results show that WKPCA algorithm is more efficient and robust than other k-prototypes algorithms.

scholarly journals The Characterization and Quality of 14 Accessions of Robusta Coffee

2021 ◽  
Vol 316 ◽  
pp. 03021
Author(s):  
Budi Martono ◽  
Eko Heri Purwanto
Keyword(s):  
Leaf Shape ◽  
Fruit Shape ◽  
Leaf Color ◽  
Qualitative And Quantitative ◽  
Robusta Coffee ◽  
Caffeine Content ◽  
Dissimilarity Coefficient ◽  
Immature Leaf ◽  
Large Groups

To produce superior varieties, gene sources of high diversity are needed. The study was intended to reveal the diversity of qualitative and quantitative characters and the quality of Robusta coffee germplasm. The study conducted at Pakuwon Experimental Garden, Sukabumi Indonesia, used 14 accessions of Robusta coffee grown by a single stem system. The observed characteristics were qualitative and quantitative characteristics, caffeine content, and cup quality. The data were analyzed descriptively and grouped by cluster analysis using the PBSTAT program. The results revealed variations in the angle of insertion of primary branches, stipule shape, immature leaf color, leaf shape, leaf apex shape, young shoot color, mature leaf color, ripe fruit color, and fruit shape. The number of bunches/branch is the characteristic of the highest variation coefficient. Eleven accessions had cupping scores between 80 and 86 with a caffeine content of 1.39 - 2.06%. The accession B4-17-1 had the lowest yield, but its final cupping test score was the highest. At the dissimilarity coefficient of 0.25, 14 accessions of Robusta coffee are divided into two large groups, while at the dissimilarity coefficient of 0.15 they consist of four groups.

scholarly journals Revisiting spatial and temporal patterns of dung beetles in Brazilian Pampa: the role of β-diversity process-related components

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Pedro Giovâni da Silva
Keyword(s):  
Species Turnover ◽  
Dung Beetle ◽  
Dung Beetles ◽  
Spatial And Temporal Patterns ◽  
Spatial And Temporal Scales ◽  
Dissimilarity Coefficient ◽  
Β Diversity ◽  
Species Abundances ◽  
Forest Ecotone

β-diversity is a key measure to understand biodiversity patterns across spatial and temporal scales. In this study, two published datasets on dung beetle (Coleoptera: Scarabaeinae) from Brazilian Pampa are re-analyzed aiming to investigate the role of β-diversity process-related components based on composition- and abundance-based approaches for both spatial (grassland-forest ecotone) and temporal (samplings along a year) scales. Dung beetles were sampled in a grassland-forest ecotone in October 2006 and in a grassland area monthly during an entire year (December 2006 to November 2007), using baited pitfall traps. β-diversity was decomposed into turnover and nestedness-resultant components based on Jaccard dissimilarity coefficient, and also into balanced variation in abundance and abundance gradients based on Bray-Curtis dissimilarity coefficient. Both environmental (spatial scale) and climatic (temporal scale) differences affected dung beetles similarly in terms of species replacement and nestedness patterns, and similarly in terms of variation in abundance and abundance gradients. For both spatial and temporal approach, the species turnover and the variation in species abundances were higher, while nestedness patterns and abundance gradients were of minor relative importance.

Genetic divergence studies through microsatellite markers in pigeonpea [Cajanus cajan (L) Millsp.]

2018 ◽  
Author(s):  
Pankaj Sharma ◽  
Inderjit Singh ◽  
Asmita Sirari ◽  
Sarvjeet Singh ◽  
Gaurav Khosla
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Cajanus Cajan ◽  
Polymorphic Information Content ◽  
Germplasm Characterization ◽  
Male Sterile ◽  
Dissimilarity Coefficient ◽  
Improvement Programs ◽  
Characterization Studies ◽  
Simple Sequence

The Genetic diversity was assessed among 96 pigeonpea accessions including 15 male sterile, 13 maintainer and 68 germplasm lines using 44 Simple Sequence Repeats (SSR) markers distributed over all the 11 chromosomes. Out of 44 SSR markers, 33 were polymorphic which showed 75% polymorphism among the used markers. For an individual primer, the alleles amplified varied from 2 to 4 with an average of 2.54. The Polymorphic Information Content (PIC) values ranged from 0.26 (CCM 0183) to 0.78 (CCM 0402 and CCM 0721). Based on 112 alleles amplified by SSR markers, the 96 genotypes were alienated into eight clusters. Cluster I and cluster VII were the largest with 22 genotypes each, cluster III and cluster IV were the smallest with two genotypes each, while cluster II, cluster V, cluster VI and cluster VIII consisted of 10, 15, 14 and 9 genotypes, respectively. Genotypes Pusa 991 and ULA 11 were found to be the most distant genotypes with highest dissimilarity coefficient (32%) where as AL 112A and AL 113A were the least distant genotypes with lowest dissimilarity coefficient (2%). Thus, highly distant genotypes can be used in pigeonpea improvement programs for getting desirable segregants. The selected panel of polymorphic SSR markers performed well in detection of genetic diversity patterns and can be used for future germplasm characterization studies in pigeonpea.

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