Intra-cluster Variation Research Articles

Development Of A Web-Based Supply Chain Management System At The Minahasa Cooperatives And Umkm Service Using The K-Means Algorithm

The development of Micro, Small and Medium Enterprises (MSMEs) plays a very important role in the regional economy. Therefore, a Supply Chain Management (SCM) system is a very important aspect of business operations that involves coordinating the activities involved in the production and delivery of goods and services to customers. SCM can be applied to small and medium enterprises (MSMEs) in the Minahasa Cooperatives and UMKM Department to improve their performance and competitiveness. SCM aims to efficiently manage the flow of goods, information and capital from suppliers to end consumers. This research aims to design and develop a web-based Supply Chain Management system for the Department of Cooperatives and MSMEs by applying the k-means algorithm for customer segmentation. In this research, the K-Means algorithm is used to group similar data points. This algorithm works by defining clusters so that the total intra-cluster variation (known as total within-cluster variation) is minimized. The results of this research can help increase the efficiency and effectiveness of supply chain management. In developing this system, customer, supplier and product data were successfully grouped into several groups based on similar characteristics using the k-means algorithm. Apart from that, the system that has been developed can also help facilitate the SCM process by utilizing information technology.

Confidence interval methods for antimicrobial resistance surveillance data

BackgroundAntimicrobial resistance (AMR) is one of the greatest global health challenges today, but burden assessment is hindered by uncertainty of AMR prevalence estimates. Geographical representation of AMR estimates typically pools data collected from several laboratories; however, these aggregations may introduce bias by not accounting for the heterogeneity of the population that each laboratory represents.MethodsWe used AMR data from up to 381 laboratories in the United States from The Surveillance Network to evaluate methods for estimating uncertainty of AMR prevalence estimates. We constructed confidence intervals for the proportion of resistant isolates using (1) methods that account for the clustered structure of the data, and (2) standard methods that assume data independence. Using samples of the full dataset with increasing facility coverage levels, we examined how likely the estimated confidence intervals were to include the population mean.ResultsMethods constructing 95% confidence intervals while accounting for possible within-cluster correlations (Survey and standard methods adjusted to employ cluster-robust errors), were more likely to include the sample mean than standard methods (Logit, Wilson score and Jeffreys interval) operating under the assumption of independence. While increased geographical coverage improved the probability of encompassing the mean for all methods, large samples still did not compensate for the bias introduced from the violation of the data independence assumption.ConclusionGeneral methods for estimating the confidence intervals of AMR rates that assume data are independent, are likely to produce biased results. When feasible, the clustered structure of the data and any possible intra-cluster variation should be accounted for when calculating confidence intervals around AMR estimates, in order to better capture the uncertainty of prevalence estimates.

Genetic diversity analysis through cluster constellation in Brinjal (Solanum melongena L.)

In present investigation, 110 locally developed genotypes from different breeding programmes in brinjal were classified into eleven clusters on the basis of their D2 values computed from Mahalanobis D2 statistics of twelve morphological traits, wherein inter-and intra-cluster distances highlighted the genetic divergence of the genotypes grouped among and within different clusters. Among all, fourth cluster was the largest with 33 genotypes; however, each of second, fifth, ninth, tenth and eleventh clusters contained only single genotype. The genotypes of eighth and tenth clusters were highly diverse (1584.40) followed by third and eighth (1431.31), eighth and ninth (1302.69), sixth and eighth (1126.33) and first and eighth (1042.91) clusters. Intra-cluster (within cluster) variation was the highest in seventh cluster (74.43) followed by eighth (61.20) and sixth (54.36) that described the diverse nature of eighteen, five and nineteen genotypes in these groups, respectively. However, PBL-268, PBGL-401, PBL-243, PSR 308 and PBOB-518 were grouped individually in IInd, Vth, IXth, Xth and XIth clusters, respectively. Overall, fifth cluster had most vigorous and high yielding ((2.82 kg/plant) genotype (PBGL-405); eighth cluster included genotypes with big round fruits and maximum fruit weight (317.43g); and tenth cluster had the earliest genotype (PSR-308) with the maximum number of fruits per plant (43.17). Out of twelve morphological traits, 94.19% diversity was brought by average fruit weight (67.86%), number of fruits per plant (17.26%), fruit yield per plant (5.37%) and fruit breadth (3.70%), however, other traits had negligible share towards the variation. This study created the foundation for future hybridization programmes in brinjal, where the parents can be selected on the basis of highly diverse groups as well as traits.

On the Complexity of SomeMax–Min Clustering Problems

Two similar problems of searching for a family of disjoint subsets (clusters) in a finite set of points in Euclidean space are considered. In these problems, the size of the smallest cluster should be maximized so that in each cluster the intracluster quadratic variation of the points with respect to the center of the cluster would not exceed a given (constant) fraction of the total quadratic variation of the points of the input set with respect to its centroid. In the first problem, the centers of intracluster variations are arbitrary points of the space given at the input. In the second problem, the centers of the intracluster variation are unknown (to be found) but must lie in the input set. Both problems are proved to be NP-hard even on the real line both in the general case when the number of the clusters is a part of the input and in the parametric case when the number of the clusters is fixed.

Estimation of phenotypic divergence in a collection of muskmelon germplasm, including Indian and exotic populations

Seventy melon genotypes, comprising of landraces, inbred lines and cultivars collected from diverse geographical locations, were evaluated for 17 morphological traits for determining the patterns of genetic diversity and relationship among genotypes. The genetic diversity based on quantitative and qualitative characters of genotypes was assessed by D2 analysis. The Euclidean’s distance-based clustering divided the germplasm in to nine clusters. Though the analysis of 17 descriptors distinctly separated momordica and wild accessions from cantalupensis, reticulatus, inodorus accessions, but it was not able to differentiate cantalupensis, reticulatus, inodorus group accessions. The inter-cluster distance varied from 759.6 between clusters 1 and 2 to 5194.5 between clusters 4 and 8. The maximum intra-cluster distance matrix was observed in cluster 9 (728.5), while cluster 6 exhibited the minimum intracluster variation (344.0). Maximum number of genotypes was grouped in cluster 1 and 7 i.e. 15 in each group. The genotype “Canary Yellow-2” present in cluster 4 did not grouped in any cluster. Overall, the clustering patterns exhibited great diversity in the germplasm for certain traits(fruit morphology and quality characteristics) which can be utilized for broadening the genetic base of muskmelon germplasm and for developing specialty melon cultivars/ hybrids with unique traits such as high beta carotene, sweetness and extended shelf life.

Spatiotemporal Analysis of Diurnal Temperature Range: Effect of Urbanization, Cloud Cover, Solar Radiation, and Precipitation

High daily temperatures in the Mediterranean and Europe have been documented in observation and modeling studies. Long-term temperature data, from 1988 to 2017, from a suburban station and an urban station in Nicosia, Cyprus have been analyzed, and the diurnal temperature range (DTR) trend was investigated. The seasonal Mann–Kendall test revealed a decreasing DTR trend of −0.24 °C/decade at the urban station and −0.36 °C/decade at the suburban station, which were attributed to an increase in the daily minimum temperature. Variations in precipitation, longwave radiation, ultraviolet-A (UVA), ultraviolet-B (UVB), cloud cover, water vapor, and urbanization were used to assess their possible relationship with regional DTR. The clustering of daytime and night-time data showed a strong relationship between the DTR and observed cloud cover, net longwave radiation, and precipitation. Clouds associated with smaller shortwave and net longwave radiation reduce the DTR by decreasing the surface solar radiation, while atmospheric absolute humidity denotes an increased daytime surface evaporative cooling and higher absorption of the short and longwave radiation. The intra-cluster variation could be reduced, and the inter-cluster variance increased by the addition of other meteorological parameters and anthropogenic sources that affect DTR in order to develop a quantitative basis for assessing DTR variations.

Genomic characterization of GII.3 noroviruses isolated from children in Zhengzhou city, China, 2015/16.

In this study, we isolated, amplified and sequenced GII.3 norovirus (NoV) strains from children admitted to a department of pediatric gastroenterology presenting with acute gastroenteritis from September 2015 to March 2016. A total of 35 stool samples were collected and eight were GII.3 NoV positive, based on sequencing. The complete genome sequences were determined for two strains while partial genome sequences, encompassing approximately 3.2 kb of the 3´end, were generated for the six other strains. Genotyping analysis of all strains indicated that they belonged to GII P12/GII.3. Phylogenetic analysis indicated that these isolated strains could be divided into two clusters. Strains in cluster IV were the most frequently isolated and exhibited less intra-cluster variation in nucleotide sequences. Our study demonstrated that the GII.P12/GII.3 recombinant strain was the dominant GII.3 NoVs in Zhengzhou city.

Generalising Ward's Method for Use with Manhattan Distances.

The claim that Ward’s linkage algorithm in hierarchical clustering is limited to use with Euclidean distances is investigated. In this paper, Ward’s clustering algorithm is generalised to use with l1 norm or Manhattan distances. We argue that the generalisation of Ward’s linkage method to incorporate Manhattan distances is theoretically sound and provide an example of where this method outperforms the method using Euclidean distances. As an application, we perform statistical analyses on languages using methods normally applied to biology and genetic classification. We aim to quantify differences in character traits between languages and use a statistical language signature based on relative bi-gram (sequence of two letters) frequencies to calculate a distance matrix between 32 Indo-European languages. We then use Ward’s method of hierarchical clustering to classify the languages, using the Euclidean distance and the Manhattan distance. Results obtained from using the different distance metrics are compared to show that the Ward’s algorithm characteristic of minimising intra-cluster variation and maximising inter-cluster variation is not violated when using the Manhattan metric.

All Anglos are alike? A study of whinging Poms and bloody-minded Aussies

Cross-cultural service research is an important topic with a rich array of empirical evidence for differences in customer perceptions, attitudes and behaviours. However, the extant literature is almost exclusively focused on differences between cultures at each end of the diversity spectrum (most commonly East vs. West). Contemporary researchers have observed that existing studies fail to acknowledge the substantially greater levels of intra-cluster variation that exist. A cultural cluster is a group of countries that reflect values, attitudes and beliefs stemming from a common cultural ancestry. This seems surprising given the anecdotal evidence and stereotypes that are portrayed in popular culture, media and art. One area where intra-cluster variation may be evident is consumer complaint behaviour and in particular within the Anglo-cultural cluster in countries. A cultural cluster is a group of countries that reflect values, attitudes and beliefs stemming from a common cultural ancestry. The aim of this study is therefore to explore and elucidate the nature of differences in consumer complaint behaviour between cultures traditionally conceived and operationalised as identical. This study presents a qualitative study of 60 in-depth interviews with consumers in the United Kingdom and Australia and identifies differences in complaining styles, parental influence and the conceptualisation of complaining.

A new metric space incorporating radon-222 for generation of back trajectory clusters in atmospheric pollution studies

A novel metric space for the clustering of back trajectories to be used in fine particle aerosol data analysis was proposed and evaluated. The metric is based on spatial and non-spatial variables incorporating great-circle distance, altitude and radon-222. Its performance was examined using the intra-cluster variation of measured and fingerprint apportioned aerosol mass as the quantitative criterion. The new metric was demonstrated to perform better than those based on great-circle distance, or a great-circle distance and altitude alone. The same criterion was applied to investigate the clustering performance as a function of the length of its back trajectories. The optimum back trajectory length was found to be dependent on the pollution source being considered. Performance tests, as well as the application of the new metric space to re-analysis of previously published results, were based on a three year long dataset comprising co-located aerosol fine particles (PM 2.5) collection and hourly measurements of radon-222 concentration. The new metric space can easily be redefined to include other trace species.

Bacterial diversity in Adélie penguin, Pygoscelis adeliae, guano: molecular and morpho-physiological approaches

The total number of bacteria and culturable bacteria in Adélie penguin ( Pygoscelis adeliae) guano was determined during 42 days of decomposition in a location adjacent to the rookery in Admiralty Bay, King George Island, Antarctica. Of the culturable bacteria, 72 randomly selected colonies were described using 49 morpho-physiological tests, 27 of which were subsequently considered significant in characterizing and differentiating the isolates. On the basis of the nucleotide sequence of a fragment of the 16S rRNA gene in each of 72 pure isolates, three major phylogenetic groups were identified, namely the Moraxellaceae/ Pseudomonadaceae (29 isolates), the Flavobacteriaceae (14), and the Micrococcaceae (29). Grouping of the isolates on the basis of morpho-physiological tests (whether 49 or 27 parameters) showed similar results to those based on 16S rRNA gene sequences. Clusters were characterized by considerable intra-cluster variation in both 16S rRNA gene sequences and morpho-physiological responses. High diversity in abundance and morphometry of total bacterial communities during penguin guano decomposition was supported by image analysis of epifluorescence micrographs. The results indicate that the bacterial community in penguin guano is not only one of the richest in Antarctica, but is extremely diverse, both phylogenetically and morpho-physiologically.

Onchocerca volvulus: Genetic Diversity of Parasite Isolates from Sudan

Higazi, T. B., Katholi, C. R., Mahmoud, B. M., Baraka, O. Z., Mukhtar, M. M., Qubati, Y. A., and Unnasch, T. R. 2001. Onchocerca volvulus: Genetic diversity of parasite isolates from Sudan. Experimental Parasitology97, 24–34. Onchocerciasis in Sudan exists in three distinct foci which exhibit differing clinical presentations. Previous studies have demonstrated that a tandemly repeated Onchocerca sequence family with a unit repeat length of 150 bp (the O-150 family) is a useful marker for deducing relationships among different O. volvulus populations. In the current study, the O-150 repeat families of O. volvulus from Sudan were analyzed and compared to each other and to those of parasites from West Africa. Similar to West African and American O. volvulus, the O-150 families of the Sudanese parasites could be divided into clusters within which little or no intracluster variation was evident, suggesting that the O-150 family in these parasites was subject to the forces of concerted evolution. Statistical analysis of the O-150 families from the different Sudanese parasite isolates, employing a nested algorithm based on an analysis of variance, revealed that O. volvulus endemic to the northern focus at Abu Hamed were significantly different from all other O. volvulus populations examined to date. In contrast, parasites from the southern and eastern foci of Sudan were indistinguishable from those endemic to the West African savanna. The significance of these data are discussed in light of knowledge of the biogeography and biology of transmission of O. volvulus in Africa.

An investigation of intracluster variation of the galaxy luminosity function in Abell clusters

La fonction de luminosite dans les amas d'Abell est etudiee a partir d'un echantillon de neuf amas d'Abell. La variation de la fonction de luminosite est analysee par rapport a la distribution spatiale des galaxies, le nombre de galaxies brillantes dans chaque amas et differentes densites avec un modele theorique

Calcium abundances in giant stars of the globular clusters M3, M13, M15, and M92

view Abstract Citations (64) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Calcium abundances in giant stars of the globular clusters M 3, M 13, M 15 and M 92. Suntzeff, N. B. Abstract The average calcium II H and K line strengths of giant stars in M3, Ml 3, Ml 5, and M92 are found to be closely correlated with the [Fe/H] of the cluster. Simple physical arguments are provided to show the observed average line strengths reproduce the difference in [Fe/H] between the clusters. The observed dispersion in H and K line strengths yields an upper limit of 0.15 dex for M 15 and M92, and 0.11 dex for M3 + M 13 for the average intracluster variation of [Ca/H], provided [Ca/H] = [Fe/H]. The dispersions drop to half these values if the calcium abundance varies independently of the iron peak abundances. Publication: The Astronomical Journal Pub Date: April 1980 DOI: 10.1086/112689 Bibcode: 1980AJ.....85..408S Keywords: Abundance; Calcium; Giant Stars; Globular Clusters; Line Spectra; Stellar Spectra; H Lines; K Lines; Rayleigh Scattering; Astrophysics full text sources ADS | data products SIMBAD (62)