In wireless networks, coded caching is an effective technique to reduce network congestion during peak traffic times. Recently, a new concept called placement delivery array (PDA) was proposed to characterize the coded caching scheme. So far, only one class of PDAs by Maddah-Ali and Niesen is known to be optimal. In this paper, we mainly focus on constructing optimal PDAs. Firstly, we derive so...

The most costly operation in the oil exploration is the well network drilling. One of the most effective ways to reduce the cost of drilling networks is decreasing the number of the required wells by selecting the optimum situation of the rig placement. In this paper, Balas algorithm is used as a model for optimizing the cost function in oil well network, where the vertical and directional dril...

In this paper, we consider the problem of optimally placing a given number of wavelength converters on a path to minimize the call blocking probability. Using a simple performance model, we first prove that uniform spacing of converters is optimal for the end-to-end performance when link loads are uniform and statistically independent. We then show that significant gains are achievable with opt...

This paper studies the optimal placement of web files for en-route web caching. It is shown that existing placement policies are all solving restricted partial problems of the file placement problem, and therefore give only sub-optimal solutions. A dynamic programming algorithm of low complexity which computes the optimal solution is presented. It is shown both analytically and experimentally t...

Distributed generators are beneficial in reducing the losses effectively compared to other methods of loss reduction. In this paper optimal DG unit placement using fuzzy logic is discussed. The optimal size of the DG unit is calculated analytically using approximate reasoning suitable nodes are determined for DG unit placement. Voltage and power loss reduction indices of distribution system nod...

Please cite this article in press as: Rostam (2008), doi:10.1016/j.compeleceng.2008 We consider an incremental optimal label placement in a closed-2PM map containing points each attached with a label. Labels are assumed to be axis-parallel square-shaped and have to be pairwise disjoint with maximum possible length each attached to its corresponding point on one of its horizontal edges. Such a l...

es wird gezeigt, dass bei der standiger zunahme der production von roheisen ,die fast ausschliesslich in hochofen erfolgt, der gestelldurchmesser und die ofeneinheit zunimmt demgegenuber der spezifische brennstoffverbrauch abnimmt. weiterhin wird die entwicklungsrichtung der stahlerzeungsverfanren wegen der wirtschaftlichen und technischen hinsicht untersucht und festgestellt, dass nuter versch...

die kultur eines jeden landes kann als ein nicht in sich abgeschlossenes system angesehen werden, das durch das handeln der menschen, durch anpassung, ubernahme, bereicherung etc. mit unterschiedlichem grad der dynamik, st?ndig im wandel ist. als eine ihrer auspr?gungen, werden in der literatur verschiedener kulturkreise die interkulturellen gemeinsamkeiten deutlich sichtbar. der ursprung vorha...

This paper studies the optimal placement of web files for en-route web caching. It is shown that existing placement policies are all solving restricted partial problems of the file placement problem, and therefore give only sub-optimal solutions. A dynamic programming algorithm of low complexity which computes the optimal solution is presented. It is shown both analytically and experimentally t...