In text analytics (Srivastava & Sahami 2009), document clustering refers to the problem of automatically grouping documents into different groups (known as clusters), such that documents in one cluster are similar to each other while being dissimilar from the ones in a different cluster. Typically, the dataset is represented using the vector model in which a set of m documents with n unique wor...

Clustered matrix data is very popular data structure, and therefore various visualization techniques for such data have been already presented. However, some of the data in our daily life or work are very sparse, and therefore the usage of display spaces is not always reasonable while using existing table or matrix data visualization techniques. Many past visualization studies have attempted to...

This paper presents a novel reliable hierarchical location-allocation model where facilities are subject to the risk of disruptions. Based on the relationship between various levels of system, a multi-level multi-flow hierarchy is considered. The heterogeneous probabilistic disruptions are investigated in which the constructed facilities have different site-dependent and independent failure rat...

Due to the increase of users the efficient usage of spectrum plays an important role in digital terrestrial television networks. In digital video broadcasting, local and global content are transmitted by single frequency network and multifrequency network respectively. Multifrequency network support transmission of global content and it consumes large spectrum. Similarly local content are well ...

the purpose of this article is to examine the relationship between organizational culture and leadership styles. organizational culture is important factor that can be influence organizational performance and also leadership is one of the key parts that can be affected organizational success. however, recognition about the relationship between these two effective factors on organizational perfo...

in this paper, a hierarchical p-hub median problem is considered that all the nodes and arcs on the network have limited capacities. proposed model has three-level where the complete network at the top level consists of the central hubs. the second and third levels consist of hub and demand nodes respectively, which are connected through star networks. also, delivery time restriction is taken i...