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1.
Construction and count of multi-output rotation symmetric resilient functions with 8 input variables
The value ranges of the number of output variables were determined respectively under the existence of multi-output rotation symmetric balanced functions and resilient functions with 2rinput variables.Based on the equivalence between the resilient functions and large sets of orthogonal arrays,some results on the construction and count of multi-output rotation symmetric balanced functions with 8 input variables were presented according to the different dimensions of output vectors,and construction and count of multi-output rotation symmetric 1-resilient functions with 8 input variables were also studied.Besides,constructions of multi-output rotation symmetric resilient functions are transformed into the problem of solving a system of equations. 相似文献
2.
《电子学报:英文版》2017,(6):1276-1283
This paper studies the properties of orbit matrix and gives a formula to compute the number of these orbit matrices on 4p variables, where p is an odd prime. It has been demonstrated that the construction of 1-resilient Rotation symmetric Boolean functions (RSBFs) on 4p variables is equivalent to solving an equation system. By the proposed method, all 1-resilient RSBFs on 12 variables can be constructed. We present a counting formula for the total number of all 1-resilient RSBFs on 4p variables. As application of our method, some 1-resilient RSBFs on 12 variables are presented. 相似文献
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Multicast connections are used in broad-band switching networks as well as in parallel processing. We consider wide-sense and strict-sense nonblocking conditions for multi-log2 N switching networks with multicast connections. We prove that such networks are wide-sense nonblocking if they are designed by vertically stacking at least t · 2n-t-1 + 2 n-2t-1 planes of a log2 N networks together, where 1 ⩽ t ⩽ [n/2] and t defines the size of a blocking window K = 2t. For t = [n/2] and n even, and for [n/2] ⩽ t ⩽ n the number of planes must be at least t · 2n-t-1 + 1 and 2t + (n - t - 1) · 2n-t-1 - 22t-n-1 + 1, respectively. In the case of strict-sense nonblocking switching networks, the number of planes is at least N/2. The results obtained in this paper show that in many cases number of planes in wide-sense nonblocking switching networks is less than those for t = [n/2] considered by Tscha and Lee (see ibid., vol.47, p.1425-31, Sept. 1999). The number of planes given in the paper is the minimum number of planes needed for wide-sense nonblocking operation provided that Algorithm 1 is used for setting up connections. The minimum number of planes for such operation in general is still open issue 相似文献
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证明了代数次数为 的偶变元平衡旋转对称布尔函数不存在非零线性结构这个公开问题,给出了代数次数为 的奇变元旋转对称布尔函数不存在非零线性结构这个公开问题成立的充分条件和不成立的必要条件。 相似文献
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Zhang Z. Yeung R.W. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1997,43(6):1982-1986
Given n discrete random variables Ω={X1,…,Xn}, associated with any subset α of {1,2,…,n}, there is a joint entropy H(Xα) where Xα={Xi: i∈α}. This can be viewed as a function defined on 2{1,2,…,n} taking values in [0, +∞). We call this function the entropy function of Ω. The nonnegativity of the joint entropies implies that this function is nonnegative; the nonnegativity of the conditional joint entropies implies that this function is nondecreasing; and the nonnegativity of the conditional mutual information implies that this function is two-alternative. These properties are the so-called basic information inequalities of Shannon's information measures. An entropy function can be viewed as a 2n -1-dimensional vector where the coordinates are indexed by the subsets of the ground set {1,2,…,n}. As introduced by Yeng (see ibid., vol.43, no.6, p.1923-34, 1997) Γn stands for the cone in IR(2n-1) consisting of all vectors which have all these properties. Let Γn* be the set of all 2n -1-dimensional vectors which correspond to the entropy functions of some sets of n discrete random variables. A fundamental information-theoretic problem is whether or not Γ¯n*=Γn. Here Γ¯n * stands for the closure of the set Γn*. We show that Γ¯n* is a convex cone, Γ2*=Γ2, Γ3*≠Γ3, but Γ¯3 *=Γ3. For four random variables, we have discovered a conditional inequality which is not implied by the basic information inequalities of the same set of random variables. This lends an evidence to the plausible conjecture that Γ¯n*≠Γn for n>3 相似文献
9.
A generalized model for 3-μm (4I 11/2 →4I 13/2)Er lasers is proposed. The essential energy transfer processes present in the single-doped Er 3+ systems (up-conversion from 4I 13/2, up-conversion from 4 I 11/2, cross-relaxation from 4S 3/2), as well as those present in Cr3+ codoped Er 3+ systems, are taken into account. In the frame of this model, the main features of 3 μm Er3+ lasers, such as long pulse or CW operation, the change of emission wavelength as a function of pumping conditions, and the effects of codoping with Ho3+ or Tm3+ ions, are explained 相似文献
10.
Ultraviolet (UV) emission has been observed in the reactions of XeF2+F2+SiH4 and XeF2+F2+F+B2H6. The emission spectra have been identified with the B 2Σ→X 2Σ transition of XeF. The emission intensity has also been examined as functions of the XeF2, F2, SiH4, and Ar concentrations. Possible mechanisms of XeF(B ) production are discussed 相似文献
11.
An almost k -wise independent sample space is a small subset of m bit sequences in which any k bits are ``almost independent'. We show that this idea has close relationships with useful cryptologic notions such as
multiple authentication codes (multiple A -codes), almost strongly universal hash families, almost k -resilient functions, almost correlation-immune functions, indistinguishable random variables and k -wise decorrelation bias of block ciphers.
We use almost k -wise independent sample spaces to construct new efficient multiple A -codes such that the number of key bits grows linearly as a function of k (where k is the number of messages to be authenticated with a single key). This improves on the construction of Atici and Stinson
\cite{AS96}, in which the number of key bits is Ω (k
2
) .
We introduce the concepts of ɛ -almost k -resilient functions and almost correlation-immune functions, and give a construction for almost k -resilient functions that has parameters superior to k -resilient functions. We also point out the connection between almost k -wise independent sample spaces and pseudorandom functions that can be distinguished from truly random functions, by a distinguisher
limited to k oracle queries, with only a small probability. Vaudenay \cite{Vaudenay99} has shown that such functions can be used to construct
block ciphers with a small decorrelation bias.
Finally, new bounds (necessary conditions) are derived for almost k -wise independent sample spaces, multiple A -codes and balanced ɛ -almost k -resilient functions.
Received September 1999 and revised January 2001 Online publication 29 August 2001 相似文献
12.
From the motivation of algebraic attacks on stream and block ciphers,the concept of algebraic immunity(AI) of a Boolean function was introduced and studied extensively.High algebraic immunity is a necessary condition for resisting algebraic attacks.In this paper,we give some lower bounds on the algebraic immunity of Boolean functions.The results are applied to give lower bounds on the AI of symmetric Boolean functions and rotation symmetric Boolean functions.Some balanced rotation symmetric Boolean functions with their AI near the maximum possible value「n/2」are constructed. 相似文献
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This paper presents a unified analytical method for computing the average E[g(x/(Sigmak=1 K yk + b))] of some arbitrary function g(.) when x is a gamma random variable and independent of the arbitrary random variables y1, y2, ..., yk. This leads to new explicit expressions for the averages of some specific functions including, erfc(radicz), exp(-z), zn, and In(1 + z), in terms of the moment generating functions of y1, y2, ..., yK. 相似文献
14.
Low complexity affine MMSE detector for iterative detection-decoding MIMO OFDM systems 总被引:1,自引:0,他引:1
Iterative turbo processing between detection and decoding shows near-capacity performance on a multiple-antenna system. Combining iterative processing with optimum front-end detection is particularly challenging because the front-end maximum a posteriori (MAP) algorithm has a computational complexity that is exponential. Sub-optimum detector such as the soft interference cancellation linear minimum mean square error (SIC-LMMSE) detector with near front-end MAP performance has been proposed in the literature. The asymptotic computational complexity of SIC-LMMSE is O(nt 2nr + ntnr 3 + ntMc2Mc) per detection-decoding cycle where nt is number of transmit antenna, nr is number of receive antenna, and Mc is modulation size. A lower complexity detector is the hard interference cancellation LMMSE (HIC-LMMSE) detector. HIC-LMMSE has asymptotic complexity of O(nt 2nr + ntMc2Mc) but suffers extra performance degradation. In this paper, two front-end detection algorithms are introduced that not only achieve asymptotic computational complexity of O(nt 2nr + ntnr 2 [Gamma (beta) + 1] + ntMc2Mc) where Gamma(beta) is a function with discrete output {-1, 2, 3, ...,nt} and O(ntMc2Mc) respectively. Simulation results demonstrate that the proposed low complexity detection algorithms offer exactly same performance as their full complexity counterpart in an iterative receiver while being computational more efficient. 相似文献
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Satyanarayana J.H. Parhi K.K. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2000,8(2):148-159
This paper presents a novel analytical approach to compute the switching activity in digital circuits at the word level in the presence of glitching and correlation. The proposed approach makes use of signal statistics such as mean, variance, and autocorrelation. It is shown that the switching activity αf at the output node f of any arbitrary circuit in the presence of glitching and correlation is computed as αf=Σi=1S-1α(f i,i+1)=Σi=1S- 1p(fi+1)(1-p(fi))(1-ρ(fi,i+1 )) (1) where ρ(fi,i+1)=ρ(fi,i+1)=(E[fi(Sn)f i+1(Sn)]- p(fi)p(fi+1))/(√(p(f i)-p(fi)2)(p(fi+1)- p(fi+12))) (2). S number of time slots in a cycle; ρ(fi,+1) time-slot autocorrelation coefficient; E[x]=expected value of x; px=probability of the signal x being “one”. The switching activity analysis of a signal at the word level is computed by summing the activities of all the individual bits constituting the signal. It is also shown that if the correlation coefficient of the higher order bits of a normally distributed signal x is ρ(xc), then the bit P0 where the correlation begins and the correlation coefficient is related hy ρ(xc)=erfc{(2(P0-1)-1)/(√2σx )} where erfc(x)=complementary error function; σx=variance of x. The proposed approach can estimate the switching activity in less than a second which is orders of magnitude faster than simulation-based approaches. Simulation results show that the errors using the proposed approach are about 6.1% on an average and that the approach is well suited even for highly correlated speech and music signals 相似文献
16.
Calderbank A.R. McGuire G. Kumar V.P. Helleseth T. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1996,42(1):217-226
Certain nonlinear binary codes contain more codewords than any comparable linear code presently known. These include the Kerdock (1972) and Preparata (1968) codes that can be very simply constructed as binary images, under the Gray map, of linear codes over Z4 that are defined by means of parity checks involving Galois rings. This paper describes how Fourier transforms on Galois rings and elementary symmetric functions can be used to derive lower bounds on the minimum distance of such codes. These methods and techniques from algebraic geometry are applied to find the exact minimum distance of a family of Z 4. Linear codes with length 2m (m, odd) and size 2(2m+1-5m-2). The Gray image of the code of length 32 is the best (64, 237) code that is presently known. This paper also determines the exact minimum Lee distance of the linear codes over Z4 that are obtained from the extended binary two- and three-error-correcting BCH codes by Hensel lifting. The Gray image of the Hensel lift of the three-error-correcting BCH code of length 32 is the best (64, 232) code that is presently known. This code also determines an extremal 32-dimensional even unimodular lattice 相似文献
17.
Cheng Tung Huang Tan Fu Lei 《Electron Devices, IEEE Transactions on》1997,44(4):601-606
A new technology for forming a titanium-silicide shallow junction by combining germanium implantation with an amorphous-silicon (or a poly-silicon) buffer layer has been proposed for MOSFETs. The use of a buffer layer between Ti and Si can avoid the consumption of bulk-silicon and the recession of TiSi2 film into the source/drain junctions during the silicidation process. In this study, the important role of germanium-implantation on the formation of TiSi2 contacted p+/n junctions was examined. After subsequent implantation of Ge+ and B+ into the TiSi2 film, samples were annealed at different temperatures to form p +/n junctions and C54-TiSi2. Since the penetration of titanium atoms was suppressed due to the germanium-implantation, the periphery leakage and the generation leakage were improved and TiSi2/Si interfaces were even smooth. Therefore, p+/n junctions with a very low leakage current (0.192 nA/cm 2 at -5 V) and an excellent forward ideality factor (n≈1.002) can be obtained. From the secondary ion mass spectrometry (SIMS) analysis, the junction depth is 400 相似文献
18.
We present the dynamical Faraday rotation of a terbium metaborate glass (25Tb2O3-75B2O3) modified with Mn2+ ions using pulsed magnetic fields, which reached up to ~16 T. The superexchange couplings of Tb3+-O 2--Tb3+ or Tb3+-O2--Mn2+ were magnetooptically observed at lower temperature. In particular, the enhancement of the Faraday rotation effect was obtained at 15 K with repetitional operation of the 16-T pulsed magnetic fields, resulting in the destruction of the dimer couplings. When the operated glasses were heated back to 300 K, only the Tb2O3-B2O3:Mn2+ exhibited a significant change in the Faraday rotation 相似文献
19.
Yongtao Wang Khurram Muhammad Kaushik Roy 《Signal Processing, IEEE Transactions on》2007,55(2):677-683
This paper addresses the design of sigma-delta modulators with arbitrary signal and noise transfer functions using a genetic algorithm (GA)-based search method. The objective function is defined to include the difference D between the magnitude of the frequency responses of the designed transfer functions and the ideal one, the quantizer gain lambdacritical for which the poles of the modulator start moving out of the unit circle, and the spread of the coefficients S. Stability can be improved by reducing lambdacritical while a smaller S reduces the implementation complexity. A GA searches for poles/zeros of the transfer functions to minimize the objective function D+w1*lambdacritical+w2*S, where w1 and w2 are two weighing factors. Numerical results demonstrate the effectiveness of the proposed method 相似文献
20.
On ternary complementary sequences 总被引:1,自引:0,他引:1
Gavish A. Lempel A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1994,40(2):522-526
A pair of real-valued sequences A=(a1,a2,...,aN) and B=(b1,b 2,...,bN) is called complementary if the sum R(·) of their autocorrelation functions RA(·) and RB(·) satisfies R(τ)=RA(τ)+R B(τ)=Σi=1N$ -τaiai+τ+Σj=1 N-τbjbj+τ=0, ∀τ≠0. In this paper we introduce a new family of complementary pairs of sequences over the alphabet α3=+{1,-1,0}. The inclusion of zero in the alphabet, which may correspond to a pause in transmission, leads both to a better understanding of the conventional binary case, where the alphabet is α2={+1,-1}, and to new nontrivial constructions over the ternary alphabet α3. For every length N, we derive restrictions on the location of the zero elements and on the form of the member sequences of the pair. We also derive a bound on the minimum number of zeros necessary for the existence of a complementary pair of length N over α3. The bound is tight, as it is met by some of the proposed constructions, for infinitely many lengths 相似文献