scholarly journals Analysis of hourly road accident counts using hierarchical clustering and cophenetic correlation coefficient (CPCC)

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Sachin Kumar ◽  
Durga Toshniwal
2019 ◽  
pp. 1625-1630
Author(s):  
Angela Vacaro de Souza ◽  
Fernando Ferrari Putti ◽  
Marcos Ribeiro da Silva Vieira ◽  
Rogério Lopes Vieites

The objective of this study was to investigate the relations between the amount of anthocyanins, carotenoids and the antioxidant activity measured by the FRAP and TEAC methods. Furthermore, pigments and the coloration of blackberry harvested fruits were measured at 3 different collection points then fruits stored in refrigerated environment and the jelly made from them, preserved in hermetically sealed glasses, without contact with light and temperature of 25ºC. In order to investigate the relations between the study variables (content of anthocyanins and carotenoids, antioxidant activity and coloration using digital colorimeter), Pearson’s correlation analysis was adopted, which indicates the existence of a positive or negative relation between two variables. The α = 5% (correlation coefficient) was used to verify the significance of the correlation. The Mahalanobis (D2) generalized distance for the clustering analysis by the mean linkage method between group of blackberry fruits and jellies was applied. Furthermore, the cophenetic correlation coefficient and multivariate analysis using major components were applied to verify the grouping of different responses of harvesting points of fresh blackberry fruit in natura and jellies. The results showed that there was correlation between the content of anthocyanins and carotenoids in fruits (0.99*) and between the same parameters in jellies. However, this behavior was not clearly observed between the pigments and the antioxidant activity. There was a positive correlation between the factors involved in the coloring of chroma fruits ‘L’, ‘a’, ‘b’ and ºHue in fruits and jellies. Blackberry jellies presented as good sources of anthocyanins and carotenoids.


Author(s):  
Mária Režňáková ◽  
Jaromír Jedlička

Companies, as well as financial institutions, deal with the same problem – verification of credibility of and enterprise. How can they identify enterprises with real threat of insolvency? One of the ways are various scoring models oriented on evaluation of the failure probability. This possibility is, however, very demanding on information about financial behaviour of a given subject. Our article discusses the utilisation of cluster analysis to identify similarities of companies and their distribution into groups. The aim of this contribution is to show what possibility are hidden in utilization of the cluster analysis and test by using of cophenetic correlation coefficient. The firms’ distribution in the class may be used to determine strategy for granting trade credits.


2004 ◽  
Vol 61 (3) ◽  
pp. 303-306 ◽  
Author(s):  
Valmor João Bianchi ◽  
Silviero Sansavini ◽  
José Carlos Fachinello

Cultivar characterization for fruit trees certification requires fast, efficient and reliable techniques. Microsatellite markers (SSR) were used in the molecular characterization of 29 Prunus spp. rootstocks. The DNA from the rootstocks was analyzed using five pre-selected SSR primers (UDP96-005, UDP96-008, UDP96-013, UDP96-18 and UDP98-414) and revealed 81 alleles, which allowed each genotype to be identified. The UDP96-005 marker generated the most information, i.e., 23 well-distributed, polymorphic alleles among all genotypes. The 21 polymorphisms produced by UDP96-013 occurred mainly as a result of high degree of variability among genotypes of the Prunophora subgenus. In the dendrogram, the five markers allowed the 29 rootstocks to be grouped into subgroups corresponding to the subgenus they belong to, either Prunophora or Amygdalus. Suitable cophenetic correlation coefficient (r=0.82) and good bootstrapping fitting value among the Prunophora subgroup cultivars were obtained. SSR markers proved to be efficient and reliable for the molecular characterization of Prunus spp. rootostocks.


2013 ◽  
Vol 48 (6) ◽  
pp. 589-596 ◽  
Author(s):  
Anderson Rodrigo da Silva ◽  
Carlos Tadeu dos Santos Dias

The objective of this work was to propose a way of using the Tocher's method of clustering to obtain a matrix similar to the cophenetic one obtained for hierarchical methods, which would allow the calculation of a cophenetic correlation. To illustrate the obtention of the proposed cophenetic matrix, we used two dissimilarity matrices - one obtained with the generalized squared Mahalanobis distance and the other with the Euclidean distance - between 17 garlic cultivars, based on six morphological characters. Basically, the proposal for obtaining the cophenetic matrix was to use the average distances within and between clusters, after performing the clustering. A function in R language was proposed to compute the cophenetic matrix for Tocher's method. The empirical distribution of this correlation coefficient was briefly studied. For both dissimilarity measures, the values of cophenetic correlation obtained for the Tocher's method were higher than those obtained with the hierarchical methods (Ward's algorithm and average linkage - UPGMA). Comparisons between the clustering made with the agglomerative hierarchical methods and with the Tocher's method can be performed using a criterion in common: the correlation between matrices of original and cophenetic distances.


1987 ◽  
Vol 65 (8) ◽  
pp. 1756-1767 ◽  
Author(s):  
Denis Barabé ◽  
Yves Bergeron ◽  
Gilles Vincent

By using numerical methods, the authors have analyzed correlations between vegetative and floral characters within the Hamamelididae subclass to determine which characters prevail in the characterization of each group of families. The cophenetic correlation coefficient, topological difference, cluster membership divergence, subtree membership divergence, and partition membership divergence show very little congruence between the vegetative and floral characters; this is explained by the heterobathmic evolution of the characters. In Hamamelididae, characters that best delimit groups are also those which play an important role in phylogeny. When both vegetative and floral characters indicate the same delimitations, the classification can be considered natural. The best discriminating characters at the structural level are generally the most important in a cladistic analysis because of their variability. If the character correlation principle is considered, an exhaustive analysis of the classification can help to solve phylogenetic problems.


2017 ◽  
Vol 32 (2) ◽  
pp. 141 ◽  
Author(s):  
Jaqueline De Oliveira Castro ◽  
Tadayuki Yanangi Junior ◽  
Patrícia Ferreira Ponciano Ferraz ◽  
Édison José Fassani

A coturnicultura tem crescido de forma considerável nos últimos anos no Brasil, deixando de ser uma atividade voltada para a subsistência e tornando-se uma atividade altamente tecnificada e rentável. Apesar do crescimento, os coturnicultores ainda encontram barreiras que dificultam a maximização da produção. Dentre as barreiras pode-se citar o ambiente de produção, que exerce influência direta sobre o comportamento das codornas, podendo este ser usado na avaliação do seu bem-estar. Assim, o presente estudo teve como objetivo avaliar o comportamento de codornas japonesas em postura submetidas a diferentes temperaturas do ar, por meio do método agrupamento hierárquico aglomerativo. As codornas foram submetidas às temperaturas de 20°C, 22°C, 24°C, 26°C, 28°C, 30°C e 32°C. Os comportamentos avaliados foram: presença no comedouro, presença no bebedouro, comportamento caracterizando estresse, sendo eles bicando, montando sobre outras codornas, repetidos movimentos com a cabeça e correndo dentro da gaiola, e comportamento de ócio, em que as codornas permaneciam paradas. Os comportamentos foram quantificados de acordo com a frequência de ocorrência em porcentagem. Os resultados foram avaliados por meio do método agrupamento hierárquico aglomerativo e coeficiente de correlação cofenético. Quando submetidos a temperaturas de 20°C as codornas apresentaram comportamento mais distinto dentre as temperaturas avaliadas. A frequência de ocorrência dos comportamentos de estresse e presença no bebedouro foi similar. O comportamento estresse apresentou maior frequência de ocorrência nas temperaturas mais baixas. O comportamento de ócio foi o de maior frequência em todas as temperaturas. O coeficiente de correlação cofenético para os comportamentos agrupados dentro das temperaturas foi 0,85 e para as temperaturas dentro dos comportamentos isolados 0,96. O intervalo de conforto térmico, obtido com base na análise comportamental de codornas japonesas em fase de postura, foi de 22°C a 24°C.  As codornas japonesas apresentaram reações condizentes com o estresse térmico, quando foram submetidas à temperatura ambiente igual a 20°C.  O método de Agrupamento Hierárquico Aglomerativo mostrou-se uma ferramenta eficaz na avaliação comportamental na área de produção animal.PALAVRAS-CHAVE: Agrupamento hierárquico aglomerativo, avaliação comportamental, coturnicultura JAPANESE LAYING QUAILS BEHAVIOR UNDER DIFFERENT TEMPERATURES ABSTRACT: The quail production has grown considerably in recent years in Brazil, from being a subsistence activity and becoming a technological and profitable activity. Despite the growth, farmers still encounter barriers that make it difficult to maximize production. Among the barriers it can be mentioned, the environment production, which exerts a direct influence on the quails behavior, that can be used to evaluate their well-being. Thus, the present study aimed to evaluate the behavior of Japanese laying quails submitted to different air dry-bulb temperatures by the clustering method. The quails were subjected to temperatures of 20°C, 22°C, 24°C, 26°C, 28°C 30°C, and 32°C. The assessed behaviors were: presence in the feeder, presence in the drinker, behavior characterizing stress, they were pecking, riding on other quail, repeated movements with the head and running inside the cage, and idle behavior, in which quails remained standing. The results were evaluated by the clustering method and cophenetic correlation coefficient.  At 20°C, quails presented more distinct behavior among the evaluated temperatures. The frequency of occurrence of stress behaviors and presence at the drinker were similar. The higher frequency of occurrence of stress behavior was in lower temperatures. The leisure behavior was the highest frequency at all air temperatures when compared to other behaviors. The cophenetic correlation coefficient for behaviors within the grouped temperatures was 0.85 and the temperature within the isolated behaviors was 0.96.  The thermal comfort interval, based on behavioral analysis of Japanese laying quails, was from 22 ° C to 24 ° C. Japanese quails presented reactions consistent with thermal stress at 20 ° C. The clustering method showed to be an effective tool in the behavioral evaluation in the area of animal production.KEYWORDS: Clustering method, behavioral evaluation, quail production. 


Author(s):  
Priscilla Ramos Carvalho ◽  
Casimiro Sepúlveda Munita ◽  
André Luiz Lapolli

The literature presents many methods for partitioning of data set, and is difficult choose which is the most suitable, since the various combinations of methods based on different measures of dissimilarity can lead to different patterns of grouping and false interpretations. Nevertheless, little effort has been expended in evaluating these methods empirically using an archaeological data set. In this way, the objective of this work is make a comparative study of the different cluster analysis methods and identify which is the most appropriate. For this, the study was carried out using a data set of 45 samples of ceramic fragments, analyzed by instrumental neutron activation analysis (INAA). The methods used for this study were: Single linkage, Complete linkage, Average linkage, Centroid and Ward. The validation was done using the cophenetic correlation coefficient and comparing these values the average linkage method obtained better results. A script of the statistical program R with some functions was created to obtain the cophenetic correlation. By means of these values was possible to choose the most appropriate method to be used in the data set.


2006 ◽  
Vol 131 (5) ◽  
pp. 622-631 ◽  
Author(s):  
E.J. Parks ◽  
J.W. Moyer ◽  
J.H. Lyerly

Fluorescent amplified fragment length polymorphism (F-AFLP) and microsatellites (SSRs) were used to evaluate new guinea impatiens (Impatiens hawkeri W. Bull) cultivars. Ninety-five quality-selected polymorphic fragments from 10 F-AFLP+3 primer combinations were used to evaluate 100 cultivars representing a variety of colors, forms, and breeding programs. Jaccard similarities and unweighted pair-group method of the arithmetic average (UPGMA) clustering formed a dendrogram with three cultivar groups, to a large extent clustering the cultivars by breeder with a high cophenetic correlation coefficient. A small insert genomic library was created and 442 kb of new guinea impatiens sequence was screened for repetitive motifs, resulting in 14 microsatellite markers. A subset of 46 cultivars representing five commercial breeding companies and 11 cultivar series was selected for microsatellite analysis. Seven loci were polymorphic, with two to six alleles per locus. Although both methods were equally effective in distinguishing the cultivars from one another, the topologies of the dendrograms for the two methods were different. The topology of the AFLP dendrogram reflected possible relationships based on cultivar series and breeding company, while the SSR dendrogram did not. The objectives of this research were to develop and validate both F-AFLP and SSR methodologies for new guinea impatiens, identify markers that can be reliably used for fingerprinting, and create a database for future cultivar comparisons.


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