the aim of this study is to analyze the impact of industrial structure of clusters on entrepreneurship in business clusters (case study: valuable metals and precious stones of isfahan's clusters). the relevant population is isfahan clusters of valuable metals and precious stones. number of population is over than 300enterprises. according to the formula of sampling structural equation mode...

Nowadays, there is an increasing use of sampling methods in network and spatial populations. Although the most common link-tracing designs such as adaptive cluster sampling and snowball sampling have advantages over conventional sampling designs such as simple random sampling and cluster sampling, these designs still present many drawbacks. Adaptive web sampling is a new link-tracing design tha...

In this paper, we propose a cluster-based cumulative representation for cluster ensembles. Cluster labels are mapped to incrementally accumulated clusters, and a matching criterion based on maximum similarity is used. The ensemble method is investigated with bootstrap re-sampling, where the k-means algorithm is used to generate high granularity clusterings. For combining, group average hierarch...

Traditional lot quality assurance sampling (LQAS) methods require simple random sampling to guarantee valid results. However, cluster sampling has been proposed to reduce the number of random starting points. This study uses simulations to examine the classification error of two such designs, a 67x3 (67 clusters of three observations) and a 33x6 (33 clusters of six observations) sampling scheme...

Spatial patterns of Meloidogyne incognita, Tylenchorhynchus claytoni, Helicotylenchus dihystera, and Criconemella ornata were analyzed using Hill's two-term local quadrat variance method (TTLQV), spectral analysis, and spatial correlation. Data were collected according to a systematic grid sampling plan from seven tobacco fields in North Carolina. Different estimates of nematode cluster size we...

Estimating the number of false negatives for a classifier when the true outcome of the classification is ascertained only for a limited number of instances is an important problem, with a wide range of applications from epidemiology to computer/network security. The frequently applied method is random sampling. However, when the target (positive) class of the classification is rare, which is of...