W artykule przedstawiono problematykę modelowania pracy oraz zużycia akumulatorów w pojazdach elektrycznych. Omówiono podstawowe metody modelowania pracy akumulatorów elektrochemicznych oraz szacowania ich zużycia podczas rozładowania zmiennego w czasie. Zaprezentowano symulację, w której analizowano zachowania się akumulatorów LiFeMnPO4 podczas obciążenia charakterystycznego dla pojazdów elektrycznych. Przedstawiono uzyskane wyniki i skomentowano.
EN
This paper presents issues of modelling of the operation and wear of batteries in electric vehicles. The basic methods of electrochemical batteries operation modelling and estimating of wear during discharge variable in time were discussed. The simulation was carried out to analyse the LiFeMnPO4 batteries operation during load typical for EV. The obtained results were presented and commented.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Dynamic capacity provisioning is a useful technique for handling the workload variations seen in cloud environment. In this paper, we propose a dynamic provisioning technique for multi-tier applications to allocate resources efficiently using queuing model. It dynamically increases the mean service rate of the virtual machines to avoid congestion in the multi-tier environments. An optimization model to minimize the total number of virtual machines for computing resources in each tier has been presented. Using the supplementary variable and the recursive techniques, we obtain the system-length distributions at pre-arrival and arbitrary epochs. Some important performance indicators such as blocking probability, request waiting time and number of tasks in the system and in the queue have also been investigated. Finally, computational results showing the effect of model parameters on key performance indicators are presented.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Ongoing research in Optical Burst Switching (OBS) requires more in-depth studies both in theory and in practice before the technology is realized. In OBS paradigm, traffic from access networks is groomed at edge OBS nodes in the forms of large chunks called bursts. This grooming called assembly is crucial in analyzing the overall performance of OBS networks as it affects the esign of almost all major functions of OBS nodes. The characteristics of assembled traffic and its effects on OBS performance have been already extensively studied in literature. In this work, the sembled traffic is studied using a transform-based approach, since it is a natural way of analyzing such processes where random variables are summed. The main contribution of this paper is formulation of distributions of burst length and burst inter-departure time in form of Laplace transforms, which are valid for general independent lengths and inter-arrival times of assembled ackets. The results can be subsequently inverted analytically or numerically to give full densities or serve as moment generating functions for partial characteristics. A simple method for the distribution of the number of packets in a burst based on discrete Markov chain is provided. Detailed analytical derivations with numerical results are presented for Erlangian traffic and verified by simulations to show good exactness of this approach.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.