Betweenness Centrality – Incremental and Faster

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Cooperative approaches for dymanic wireless charging of Electric Vehicles in a smart city

In this paper, a method of electric vehicles charging with the use of large truck/bus vehicles moving along national highways and provincial roads is proposed and described. The method relies on charging vehicles from trucks while moving either with plug in electric connection or by electromagnetic induction via loosely coupled coils. Open research challenges and several avenues or opportunities for future research on Electric Vehicles Charging are outlined. The proposed method overcomes the disadvantages of the so far known techniques. The advantages of this method compared to the so far proposed methods are a) economical, easy and safe procedure, b) increase of the energy transfer efficiency factor, c) minimization of the delay in vehicle movement during the charging procedure and d) reduction of the environmental contamination with CO2 or electromagnetic radiation. © 2014 IEEE

The Ground Effect and the Mirror Effect in small air gaps

In the present paper we investigate the Ground Effect of small rod-rod air gaps, in connection to the Mirror Effect of rod-plate air gaps. The Ground Effect is a phenomenon, which is observed due to the fact that in air gap arrangements one of the two electrodes is usually at earth potential (grounded). The Mirror Effect is valid in rod-plate air gaps when the plate's diameter is very big. The field distribution along the axis of the gaps is analyzed with the Finite Element Method. The maximum values of the field strength in the gap are recorded for the two different arrangements the one with one electrode grounded, and the other with symmetrical charging of the electrodes. The distribution of the field along the axis of the gap is strongly affected by the gap length, the geometry of the arrangement, and the electrode, chosen to be at earth potential (grounded). The Mirror Effect establishes equivalence between the rod-plate and rod-rod arrangements. It is resulted that the Ground Effect and the Mirror Effect influence the corona onset and the breakdown voltage of the air gaps analogically. It is intense in small air gaps, while the influence of the corona current appears in longer air gaps and overlaps the Ground Effect. The principle of action-reaction is valid

Optimization of corona effects in small air gaps stressed by DC voltages

In the present paper methods of minimizing or maximizing the values of the Corona onset voltage and the Corona current in small rod-plate air gaps are investigated. The geometry and the way of grounding and charging the electrodes, (Ground Effect), the gap length, the existence of barrier in the gap (Barrier Effect), and the conditions of the air in the gap, are some factors, which influence greatly the distribution of the electric field in the gap, and hence the above values. Combining experimental and simulation-theoretical work, it is resulted that: a) the electrode chosen to be ground, strongly influences the distribution of the field and hence the Corona onset voltage and the corona current in rod-plate air gaps. When the rod is grounded the value of the corona onset voltage is higher and the corona current is significantly smaller. b) A dielectric barrier, when placed in specific positions in the gap, increases the Corona onset voltage to a maximum value, and annihilates the Corona Current. © 2012 IEEE

The Ground Effect and the Mirror Effect in small air gaps

In the present paper we investigate the Ground Effect of small rod-rod air gaps, in connection to the Mirror Effect of rod-plate air gaps. The Ground Effect is a phenomenon, which is observed due to the fact that in air gap arrangements one of the two electrodes is usually at earth potential (grounded). The Mirror Effect is valid in rod-plate air gaps when the plate's diameter is very big. The field distribution along the axis of the gaps is analyzed with the Finite Element Method. The maximum values of the field strength in the gap are recorded for the two different arrangements the one with one electrode grounded, and the other with symmetrical charging of the electrodes. The distribution of the field along the axis of the gap is strongly affected by the gap length, the geometry of the arrangement, and the electrode, chosen to be at earth potential (grounded). The Mirror Effect establishes equivalence between the rod-plate and rod-rod arrangements. It is resulted that the Ground Effect and the Mirror Effect influence the corona onset and the breakdown voltage of the air gaps analogically. It is intense in small air gaps, while the influence of the corona current appears in longer air gaps and overlaps the Ground Effect. The principle of action-reaction is valid

The Ground Effect and the Mirror Effect in small air gaps

In the present paper we investigate the Ground Effect of small rod-rod air gaps, in connection to the Mirror Effect of rod-plate air gaps. The Ground Effect is a phenomenon, which is observed due to the fact that in air gap arrangements one of the two electrodes is usually at earth potential (grounded). The Mirror Effect is valid in rod-plate air gaps when the plate's diameter is very big. The field distribution along the axis of the gaps is analyzed with the Finite Element Method. The maximum values of the field strength in the gap are recorded for the two different arrangements the one with one electrode grounded, and the other with symmetrical charging of the electrodes. The distribution of the field along the axis of the gap is strongly affected by the gap length, the geometry of the arrangement, and the electrode, chosen to be at earth potential (grounded). The Mirror Effect establishes equivalence between the rod-plate and rod-rod arrangements. It is resulted that the Ground Effect and the Mirror Effect influence the corona onset and the breakdown voltage of the air gaps analogically. It is intense in small air gaps, while the influence of the corona current appears in longer air gaps and overlaps the Ground Effect. The principle of action-reaction is valid