In object oriented database management systems, clustering has proven to be one of the most effective performance enhancement techniques. Existing clustering algorithms are mainly static, that is re-clustering the object base when the database is off-line. However, this type of re-clustering cannot be used when 24-hour database access is required. In such situations dynamic clustering is necess...

We propose a dynamic clustering model for uncovering latent time-varying group structures in multivariate panel data. The is three ways. First, the cluster location and scale matrices are to track gradual changes characteristics over time. Second, all units can transition between clusters based on Hidden Markov (HMM). Finally, HMM’s matrix depend lagged distances as well economic covariates. Mo...

Researchers have observed that multistage clustering can accelerate convergence and improve clustering quality. Two-stage and two-phase fuzzy C-means (FCM) algorithms have been reported. In this paper, we demonstrate that the FCM clustering algorithm can be improved by the use of static and dynamic single-pass incremental FCM procedures. Keywords-Clustering; Fuzzy C-Means Clustering; Incrementa...

Due to the resource constraint and dynamic parameters, reducing energy consumption became the most important issues of wireless sensor networks topology design. All proposed hierarchy methods cluster a WSN in different cluster layers in one step of evolutionary algorithm usage with complicated parameters which may lead to reducing efficiency and performance. In fact, in WSNs topology, increasin...

Permeability can be directly measured using cores taken from the reservoir in the laboratory. Due to high cost associated with coring, cores are available in a limited number of wells in a field. Many empirical models, statistical methods, and intelligent techniques were suggested to predict permeability in un-cored wells from easy-to-obtain and frequent data such as wireline logs. The main obj...

Algorithms or target functions for graph clustering rarely admit quality guarantees or optimal results in general. Based on properties of minimum-cut trees, a clustering algorithm by Flake et al. does however yield such a provable guarantee, which ensures the quality of bottlenecks within the clustering. We show that the structure of minimum s-t-cuts in a graph allows for an efficient dynamic u...

We consider a context-based dynamic pricing problem of online products, which have low sales. Sales data from Alibaba, major global retailer, illustrate the prevalence low-sale products. For these existing single-product algorithms do not work well due to insufficient samples. To address this challenge, we propose policies that concurrently perform clustering over product demand and set individ...