We investigate optimal geographical caching in heterogeneous cellular networks, where different types of base stations (BSs) have different cache capacities. The content library contains files with different popularities. The performance metric is the total hit probability. The problem of optimally placing content in all BSs jointly is not convex in general. However, we show that when BSs are d...

Nowadays, using distributed generation (DG) resources, such as wind and solar, also improving the voltage profile in distribution companies has been considered. As optimal placement and sizing of shunt capacitors become more prevalent, utilities want to determine the impact of the various capacitors placement in distribution systems. Locating and determining the optimal capacity of shunt capaci...

This paper deals with the replica placement problem on fully homogeneous tree networks known as the Replica Placement optimization problem. The client requests are known beforehand, while the number and location of the servers are to be determined. We investigate the latter problem using the Closest access policy when adding QoS and bandwidth constraints. We propose an optimal algorithm in two ...

The experience of past prominent earthquakes establishes the fact that the structure’s catastrophes and casualties can be dramatically decreased through the use of self-centering systems. A promising post-tensioned self-centering yielding braced system (PT-SCYBS) has been developed, comprising of two main components, including the post-tensioned wires, exhibiting the desirable self-centering pr...

This paper proposes a sensor placement method for three-dimensional point source localization using multiple sensors. An observation model of multiple sensors and one source of unknown position is introduced. Given that model, the minimum number of sensors needed to localize the source is determined, and an optimal sensor placement is derived. The placement is optimal in the sense that it minim...

The analysis of power system observability and the rules of PMU placement are concisely presented. Several algorithms of PMU placement as well as their differences and relations are discussed in details: a graph-theoretic procedure based on Depth First Search can find the optimal placement the most quickly; Simulated Annealing Method can help the algorithm converge to global optimum. Base on th...

In this paper, we consider the problem of placing energy storage resources in a power network when all storage devices are optimally controlled to minimize system-wide costs. We propose a discrete optimization framework to accurately model heterogeneous storage capital and installation costs as these fixed costs account for the largest cost component in most grid-scale storage projects. Identif...