We give a new LP-rounding 1.724-approximation algorithm for the metric Fault-Tolerant Uncapacitated Facility Location problem. This improves on the previously best known 2.076-approximation algorithm of Shmoys & Swamy. Our work applies a dependent-rounding technique in the domain of facility location. The analysis of our algorithm benefits from, and extends, methods developed for Uncapacitated ...

because of urgent needs of groundwater resources in the tochal region of north tehran, an integration of electric and electromagnetic methods was applied to investigate the location and the direction of water bearing fractures. first, the vlf electromagnetic profiling was performed on suitable places and two locations were detected for supplementary resistivity surveys. then, a number of vertic...

This paper presents a novel approach for fault type estimation in power systems. The Fault type estimation is the first step to estimate instantaneous voltage, voltage sag magnitude and duration in a three-phase system at fault duration. The approach is based on time-domain state estimation where redundant measurements are available. The current based model allows a linear mapping between the m...

Spectrum-based fault localization (SBFL), which utilizes spectrum information of test cases to calculate the suspiciousness each statement in a program, can reduce developers’ effort. However, applying redundant from suite incurs heavy burden, especially restricted resource environment, and it is expensive infeasible inspect results input. Prioritizing/selecting appropriate important enable pra...

The location of ground faults in railway electric lines in 2 × 5 kV railway power supply systems is a difficult task. In both 1 × 25 kV and transmission power systems it is common practice to use distance protection relays to clear ground faults and localize their positions. However, in the particular case of this 2 × 25 kV system, due to the widespread use of autotransformers, the relation bet...

Teed lines are widely used in rural power networks in China. The paper theoretically analyzes the voltages and currents when a single line-to-ground fault occurs, constructs a new mathematical model for fault location on the teed lines, performs corresponding MATLAB simulations. Simulation results show that currents near the source (bus M) are almost independent of fault positions and fault res...