The station location problem consists of placing new stations along the railway tracks of an existing network in order to increase the number of users. In this paper we consider the problem for a railway network consisting of two intersecting lines forming an angle α. An approach for solving the problem in polynomial time for sufficiently large angles α is presented.

The problem of finding optimal locations of base stations, their pilot powers and channel assignments in UMTS mobile networks belongs to a class of NP-hard problems, and hence, metaheuristics optimization algorithms are widely used for this task. Invasive Weed Optimization (IWO) algorithm is relatively novel and succussed in several real-world applications. Our experiments demonstrate that the ...

The most sensitive and reliable methods for locating small-magnitude regional seismic events using records from a single, three-component station require knowledge of the near-station and along-path crustal structure. Unfortunately, obtaining information about crustal structure is time-consuming and may be costly. Furthermore, different location methods may be required depending on the lateral ...

A new computer-based ELF/VLF system for locating lightning discharges has been developed. Both the arrival azimuths of atmospherics and the distances to their sources are estimated. The direction-finding technique uses the Poynting vector calculated directly in the time domain over the full band pass of the receiver. Both the distance of the lightning discharge and the ionospheric height can be...

We consider the following location problem. New 5G networks are deployed by two competitive operators (called resp. O1 and O2), which we refer to as a leader and a follower due to their sequential entering the market. They compete to serve clients by installing and configuring base stations (BS). We assume that the leader had already made a decision and operating a 5G network. Follower arrives ...

Radio planning and coverage optimization are critical issues when deploying and expanding third generation cellular systems. We investigate mixed integer programming models for locating and configuring base stations in UMTS networks so as to maximize coverage and minimize installation costs. The overall model considers both uplink and downlink directions, that we studied separately in Amaldi et...

The emergency service station (ESS) location problem has been widely studied in the literature since 1970s. There has been a growing interest in the subject especially after 1990s. Various models with different objective functions and constraints have been proposed in the academic literature and efficient solution techniques have been developed to provide good solutions in reasonable times. How...

Background:A critical environmental impact of the petroleum industry is the contamination of soil by oil and other related products which are highly toxic and exhibit molecular recalcitrance. Therefore, this study focused on investigating the total amount of petroleum hydrocarbons (TPHs) in soil of urban fuel stations in Hamedan City, Iran. Methods:Thirteen high traffic urban fuel stations ...

Wireless sensor networks are widely used to monitor valuable objects such as rare animals or armies. Once an object is detected, the source, i.e., the sensor nearest to the object, generates and periodically sends a packet about the object to the base station. Since attackers can capture the object by localizing the source, many protocols have been proposed to protect source location. Instead o...