COMPARATIVE BATTERY EFFICIENCY ANALYSIS FOR HYBRID ELECTRIC VEHICLES BASED ON MATLAB MODELLING

The present paper introduces a new comparative analysis method that is applied on different hev battery types, with the scope of enhancing the energy efficiency. The research is based on matlab modeling and hardware in the loop approach. The study considers a set of critical parameters that influence the system performance. The added value is given by the comparative overview as a result of the applied analysis. This method identifies also the set of parameter values needed for a better performance that can be afterwards considered in developing future battery types. A set of 4 case studies are proposed and the efficiency of the analysis method is proven through a series of simulation results. The motivation of the research is given by the fact that the battery is one of the most important components in hybrid electric vehicles architecture. A good understanding of different battery behavior helps in using the best suited battery system for a certain architecture resulting in a better control strategy, better energy efficiency and better costs. The advantage of this method is that the battery performance can be assessed in an early stage of development. The results contribute to the practical need of developing new battery control systems at higher quality standards

COMPARATIVE BATTERY EFFICIENCY ANALYSIS FOR HYBRID ELECTRIC VEHICLES BASED ON MATLAB MODELLING

The present paper introduces a new comparative analysis method that is applied on different hev battery types, with the scope of enhancing the energy efficiency. The research is based on matlab modeling and hardware in the loop approach. The study considers a set of critical parameters that influence the system performance. The added value is given by the comparative overview as a result of the applied analysis. This method identifies also the set of parameter values needed for a better performance that can be afterwards considered in developing future battery types. A set of 4 case studies are proposed and the efficiency of the analysis method is proven through a series of simulation results. The motivation of the research is given by the fact that the battery is one of the most important components in hybrid electric vehicles architecture. A good understanding of different battery behavior helps in using the best suited battery system for a certain architecture resulting in a better control strategy, better energy efficiency and better costs. The advantage of this method is that the battery performance can be assessed in an early stage of development. The results contribute to the practical need of developing new battery control systems at higher quality standards

Analysis of Linear Block Codes as Sources with Memory

4 pagesInternational audienceThe linear, binary, block codes with no equally likely probabilities for the binary symbols are analyzed. The encoding graph for systematic linear block codes is proposed. These codes are seen as sources with memory and the information quantities H(S,X), H(S), H(X), H(X|S), H(S|X), I(S,X) are derived. On the base of these quantities, the code performances are analyzed

Infinite anti-uniform sources

6 pagesInternational audienceIn this paper we consider the class of anti-uniform Huffman (AUH) codes for sources with infinite alphabet. Poisson, negative binomial, geometric and exponential distributions lead to infinite anti-uniform sources for some ranges of their parameters. Huffman coding of these sources results in AUH codes. We prove that as a result of this encoding, we obtain sources with memory. For these sources we attach the graph and derive the transition matrix between states, the state probabilities and the entropy. If c0 and c1 denote the costs for storing or transmission of symbols "0" and "1", respectively, we compute the average cost for these AUH codes

INFINITE ANTI - UNIFORM SOURCES WITH GEOMETRIC DISTRIBUTION

11 pagesInternational audienceIn this paper we consider the class of anti-uniform Huffman (AUH) codes for sources with infinite alphabet generated by geometric distribution. Huffman encoding of these sources results in AUH codes. As a result of this encoding, we obtain sources with memory. The entropy and average cost of these sources with memory are derived. We perform an analogy between sources with memory and discrete memoryless channels, showing that the entropy of the source with memory is similar to the mean error of the discrete memoryless channel. The information quantity I(X,S) specifies for AUH codes whether they are with memory or not, as it differs from zero or is equal to zero, respectively

Frequency content oriented modification of quantization matrix in DCT-based compression

In order to improve the compression rate for comparable values of error metrics, we propose a method to modify the standard quantization matrix used in JPEG, according to image frequency content. Unlike the method which allows varying levels of image compression and quality, by scaling all the elements in the quantization matrix by the same factor, we propose a way to modify differently the quantization step for low and high frequencies, respectively

Analysis of cubic permutation polynomials for turbo codes

Quadratic permutation polynomials (QPPs) have been widely studied and used as interleavers in turbo codes. However, less attention has been given to cubic permutation polynomials (CPPs). This paper proves a theorem which states sufficient and necessary conditions for a cubic permutation polynomial to be a null permutation polynomial. The result is used to reduce the search complexity of CPP interleavers for short lengths (multiples of 8, between 40 and 352), by improving the distance spectrum over the set of polynomials with the largest spreading factor. The comparison with QPP interleavers is made in terms of search complexity and upper bounds of the bit error rate (BER) and frame error rate (FER) for AWGN and for independent fading Rayleigh channels. Cubic permutation polynomials leading to better performance than quadratic permutation polynomials are found for some lengths.Comment: accepted for publication to Wireless Personal Communications (19 pages, 4 figures, 5 tables). The final publication is available at springerlink.co

When Is the Number of True Different Permutation Polynomials Equal to 0?

In this paper, we have obtained the prime factorization form of positive integers N for which the number of true different fourth- and fifth-degree permutation polynomials (PPs) modulo N is equal to zero. We have also obtained the prime factorization form of N so that the number of any degree PPs nonreducible at lower degree PPs, fulfilling Zhao and Fan (ZF) sufficient conditions, is equal to zero. Some conclusions are drawn comparing all fourth- and fifth-degree permutation polynomials with those fulfilling ZF sufficient conditions