The problem of maximal hub covering as a challenging problem in operation research. Transportation programming seeks to find an optimal location of a set of hubs to reach maximum flow in a network. Since the main structure's parameters of the problem such as origin-destination flows, costs and travel time, change periodically in the real world applications, new issues arise in handling it. In t...

Location-allocation problems arise in several contexts, including supply chain and data mining. In its most common interpretation, the basic problem consists of optimally locating facilities and allocating customers to facilities so as to minimize the total cost. The standard approach to solving location-allocation problems is to model alternative location sites and customers as discrete entiti...

Natural disasters, such as earthquakes, affect thousands of people and can cause enormous financial loss. Therefore, an efficient response immediately following a natural disaster is vital to minimize the aforementioned negative effects. This research paper presents a network design model for humanitarian logistics which will assist in location and allocation decisions for multiple disaster per...

The channel allocation is one of the key problems in the design of the wireless network, as it greatly influences the throughput and performance of the network. Firstly we introduce the channel propagation model, which is able to accurately reflect the signal attenuation, the network interference and other factors in the actual environment. Based on this work, we put forward the channel allocat...

In this paper we address the issue of locating hierarchical facilities in the presence of congestion. Two hierarchical models are presented, where lower level servers attend requests first, and then, some of the served customers are referred to higher level servers. In the first model, the objective is to find the minimum number of servers and their locations that will cover a given region with...

The dust extinction towards bright H ii region-sin NGC 598 and NGC 5457 has been studied in detail by forming line ratios of Balmer and Paschen emission lines covering a large wavelength range. Three homogeneous models of the geometrical distribution of the emitting sources and the obscuring dust have been tested. Only for low extinctions can the data be fit by a homogeneous slab. For most of t...

Web services are independent programmable application components which scatter over the Internet. Due to the improvement on local computing power and development on high-speed Internet, network latency has a significant impact on determining the service response time. Thus, physical locations of web services and users should be taken into account for web service composition. In this paper, we p...

The allocation of facilities and customers is a key problem in the design of supply chains of companies. In this paper, this issue is approached by partitioning the territory in areas where the distribution points are allocated. The demand is modelled through a set of continuous functions based on the population density of the geographic units of the territory. Because the partitioning problem ...

The main aim of this research is to develop and apply location optimization formulations in conjunction with a geographic information system (GIS) to allocate police patrol vehicles such that the police car road coverage in a specific area is maximized. We will demonstrate this using a case study based on the interurban road network of Northern Israel. Currently it is standard practice around t...

In this paper we consider the problem of locating N new facilities with respect to M existing facilities in the plane and in the presence of polyhedral barriers. We assume that a barrier is a region where neither facility location nor traveling is permitted. For the resulting multi-dimensional mixed-integer optimization problem two different alternate location and allocation procedures are deve...