iran is facing dust storms every year and frequently. this phenomenon has affected, especially in recent years, various aspects of people's lives. the aim of this research is iran’s seasonal clustering in terms of dust storms frequency with visibility less than 1000 and 500 m for the period of 1987–2008. for this purpose, we used the data of 87 synoptic stations that had suitable spatial d...

A Simple logarithmic approximation This problem can be formulated as a set cover problem. Given an instance (D,F, f, d) of the facility location problem, it can be transformed into an instance of a set cover problem (X,S, cost) by • setting X = D, and • setting S = {(i, A) : i ∈ F,A ⊆ D}. (i, A) covers elements of the set A. The cost of the set (i, A) is fi + ∑ j∈A dij . We can then use the sta...

Understanding the dynamics of evolving social or infrastructure networks is a challenge in applied areas such as epidemiology, viral marketing, or urban planning. During the past decade, data has been collected on such networks but has yet to be fully analyzed. We propose to use information on the dynamics of the data to find stable partitions of the network into groups. For that purpose, we in...

In the maximum facility location problem, we are given a set of clients C and facilities F . Assigning a client u to a facility v incurs a cost w uv and each facility has an associated interval I v on the real line. Our goal is to assign as many clients to open facilities in order to maximise the cost of assignment, subject to the constraint that open facilities cannot have their respective int...

Facility location decisions are a critical element in strategic planning for a wide range of private and public ®rms. The rami®cations of siting facilities are broadly based and long-lasting, impacting numerous operational and logistical decisions. High costs associated with property acquisition and facility construction make facility location or relocation projects long-term investments. To ma...

We present a deterministic kinetic data structure for the facility location problem that maintains a subset of the moving points as facilities such that, at any point of time, the accumulated cost for the whole point set is at most a constant factor larger than the current optimal cost. At any point of time, the cost that arise for a point depends on the status and the position of the point. In...

In recent years exemplar clustering has become a popular tool for applications in document and video summarization, active learning, and clustering with general similarity, where cluster centroids are required to be a subset of the data samples rather than their linear combinations. The problem is also well-known as facility location in the operations research literature. While the problem has ...

traditional leveraging statistical methods for analyzing today’s large volumes of spatial data have high computational burdens. to eliminate the deficiency, relatively modern data mining techniques have been recently applied in different spatial analysis tasks with the purpose of autonomous knowledge extraction from high-volume spatial data. fortunately, geospatial data is considered a proper s...