We consider the analysis of spectral clustering algorithms for community detection under a stochastic block model (SBM). A general spectral clustering algorithm consists of three steps: (1) regularization of an appropriate adjacency or Laplacian matrix (2) a form of spectral truncation and (3) a k-means type algorithm in the reduced spectral domain. By varying each step, one can obtain differen...

Clustering aims at grouping of data into clusters based on the similarity between them. It is the pattern of the data that governs grouping. In this paper, we propose method for clustering that is based on finding closeness between the data series. A novel method referred as Clustering with Closeness factor (CCF) is proposed that works in two phases and is not pre-bound with clusters numbers. T...

We develop a three-step fuzzy logic-based algorithm for clustering categorical attributes, and we apply it to analyze cultural data. In the first step the algorithm employs an entropy-based clustering scheme, which initializes the cluster centers. In the second step we apply the fuzzy c-modes algorithm to obtain a fuzzy partition of the data set, and the third step introduces a novel cluster va...

To accomplish analyses on the properties of neuronal populations it is mandatory that each unit activity is identified within the overall noise background and the other unit signals merged in the same trace. The problem, addressed as a clustering one, is particularly difficult as no assumption can be made on the prior data distribution. We propose an algorithm that achieves this goal by a two-p...

High-accuracy location identification is the basis of location awareness and location services. However, because of the influence of GPS signal loss, data drift and repeated access in the individual trajectory data, the efficiency and accuracy of existing algorithms have some deficiencies. Therefore, we propose a two-step clustering approach to extract individuals’ locations according to their ...

We examine the formation of giant elliptical galaxies using their globular cluster (GC) systems as probes of their evolutionary history. The bimodal distributions of GC metallicities in such galaxies are often cited as evidence for the formation of giant elliptical galaxies through mergers involving gas-rich spirals, with the metal-rich GCs forming during the merger process. We explore an alter...

We study the stability of the giant gravitons in the string theory background with NSNS B field. We consider the perturbation of giant gravitons formed by a probe D(8− p) brane in the background generated by D(p− 2)D(p) branes for 2 ≤ p ≤ 5. We use the quadratic approximation to the brane action to find the equations of motion. The vibration modes for ρ , φ and r are coupled, while those of xk’...

Paying off the mortgage, once a widespread rite of passage for homeowners approaching retirement, has become less common in recent years. Concerns are mounting that the increased prevalence of housing debt among older homeowners could compromise financial security in retirement by expanding housing affordability problems, crimping essential nonhousing spending, increasing vulnerability to home ...