77,357 research outputs found
Modelling and simulation of electric drive vehicle based on space vector modulation technique and field oriented control strategy
Recently, the electric vehicle has emerged as a powerful platform for mitigating energy crisis and reducing environmental pollution in the transportation sector. The major drawbacks of electrically powered automobile that limits its competitiveness with the internal combustion engine counterpart are the vehicle driving range and battery energy capacity. Hence, limited energy storage warrants the need for an effective and efficient energy utilisation in the overall system. This paper uses Field Oriented Control algorithm and Space Vector Modulation technique to enhance and to optimise energy saving at the same time improve the vehicle induction motor efficiency. A simple electric vehicle drive with vehicle dynamic and tractive loads for motor driving load were modelled and simulated using Matlab/Simulink. Simulation results show that modelled vehicle speed satisfied the acceleration index for the electric vehicle
Base Station Switching Problem for Green Cellular Networks with Social Spider Algorithm
With the recent explosion in mobile data, the energy consumption and carbon
footprint of the mobile communications industry is rapidly increasing. It is
critical to develop more energy-efficient systems in order to reduce the
potential harmful effects to the environment. One potential strategy is to
switch off some of the under-utilized base stations during off-peak hours. In
this paper, we propose a binary Social Spider Algorithm to give guidelines for
selecting base stations to switch off. In our implementation, we use a penalty
function to formulate the problem and manage to bypass the large number of
constraints in the original optimization problem. We adopt several randomly
generated cellular networks for simulation and the results indicate that our
algorithm can generate superior performance
Scalable energy-efficient routing in mobile Ad hoc network
The quick deployment without any existing infrastructure makes mobile ad hoc networks (MANET) a striking choice for dynamic situations such as military and rescue operations, disaster recovery, and so on and so forth. However, routing remains one of the major issues in MANET due to the highly dynamic and distributed environment. Energy consumption is also a significant issue in ad hoc networks since the nodes are battery powered. This report discusses some major dominating set based approaches to perform energy efficient routing in mobile ad hoc networks. It also presents the performance results for each of these mentioned approaches in terms of throughput, average end to end delay and the life time in terms of the first node failure. Based on the simulation results, I identified the key issues in these protocols regarding network life time. In this report, I propose and discuss a new approach “Dynamic Dominating Set Generation Algorithm” (DDSG) to optimize the network life time. This algorithm dynamically selects dominating nodes during the process of routing and thus creates a smaller dominating set. DDSG algorithm thereby eliminates the energy consumption from the non-used dominating nodes. In order to further increase the network life time, the algorithm takes into consideration the threshold settings which helps to distribute the process of routing within the network. This helps to eliminate a single dominating node from getting drained out by continuous transmission and reception of packets. In this report, the detailed algorithmic design and performance results through simulation is discussed
Event-Driven Molecular Dynamics in Parallel
Although event-driven algorithms have been shown to be far more efficient
than time-driven methods such as conventional molecular dynamics, they have not
become as popular. The main obstacle seems to be the difficulty of
parallelizing event-driven molecular dynamics. Several basic ideas have been
discussed in recent years, but to our knowledge no complete implementation has
been published yet. In this paper we present a parallel event-driven algorithm
including dynamic load-balancing, which can be easily implemented on any
computer architecture. To simplify matters our explanations refer to a basic
multi-particle system of hard spheres, but can be extended easily to a wide
variety of possible models.Comment: 10 pages, 9 figure
Quantum Analogue Computing
We briefly review what a quantum computer is, what it promises to do for us,
and why it is so hard to build one. Among the first applications anticipated to
bear fruit is quantum simulation of quantum systems. While most quantum
computation is an extension of classical digital computation, quantum
simulation differs fundamentally in how the data is encoded in the quantum
computer. To perform a quantum simulation, the Hilbert space of the system to
be simulated is mapped directly onto the Hilbert space of the (logical) qubits
in the quantum computer. This type of direct correspondence is how data is
encoded in a classical analogue computer. There is no binary encoding, and
increasing precision becomes exponentially costly: an extra bit of precision
doubles the size of the computer. This has important consequences for both the
precision and error correction requirements of quantum simulation, and
significant open questions remain about its practicality. It also means that
the quantum version of analogue computers, continuous variable quantum
computers (CVQC) becomes an equally efficient architecture for quantum
simulation. Lessons from past use of classical analogue computers can help us
to build better quantum simulators in future.Comment: 10 pages, to appear in the Visions 2010 issue of Phil. Trans. Roy.
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