Relating Differential Distribution Tables to Other Properties of of Substitution Boxes

Due to the success of differential and linear attacks on a large number of encryption algorithms, it is important to investigate relationships among various cryptographic, including differential and linear, characteristics of an S-box (substitution box). After discussing a precise relationship among three tables, namely the difference, auto-correlation and correlation immunity distribution tables, of an S-box, we develop a number of results on various properties of S-boxes. More specifically, we show (1) close connections among three indicators of S-boxes, (2) a tight lower bound on the sum of elements in the leftmost column of its differential distribution table, (3) a non-trivial and tight lower bound on the differential uniformity of an S-box, and (4) two upper bounds on the nonlinearity of S-boxes (one for a general, not necessarily regular, S-box and the other for a regular S-box).     

The transcendental rank of the formulas of an S1-categorical theory

In this paper we investigate the transcendental rank introduced by Morley. We introduce the concept of a fibering and prove a series of lemmas about fibering, on the basis of which we prove the main theorems: on an estimate for the rank of a formula (Theorem 3); on the summation of ranks (Theorem 2); and a reproof of Baldwin's theorem on the finiteness of the rank of S₁-categorical theories (Theorem 1).     

Divergence of the Fourier series by generalized Haar systems at points of continuity of a function

We obtain a connection between the Dirichlet kernels and partial Fourier sums by generalized Haar and Walsh (Price) systems. Based on this, we establish an interrelation between convergence of the Fourier series by generalized Haar and Walsh (Price) systems. For any unbounded sequence we construct a model of continuous function on a group (and even on a segment [0, 1]), whose Fourier series by generalized Haar system generated by this sequence, diverges at some point.     

On simultaneous triangularization of collections of compact operators

In this paper we consider collections of compact (resp. C_p class) operators on arbitrary Banach (resp. Hilbert) spaces. For a subring R of reals, it is proved that an R-algebra of compact operators with spectra in R on an arbitrary Banach space is triangularizable if and only if every member of the algebra is triangularizable. It is proved that every triangularizability result on certain collections, e.g., semigroups, of compact operators on a complex Banach (resp. Hilbert) space gives rise to its counterpart on a real Banach (resp. Hilbert) space. We use our main results to present new proofs as well as extensions of certain classical theorems (e.g., those due to Kolchin, McCoy, and others) on arbitrary Banach (resp. Hilbert) spaces.     

关于树的代数连通度的Fiedler不等式的新证明

设T为含n个顶点的树，L(T)为其Laplace矩阵，L(T)的次小特征值α(T)称为T的代数连通度，Fiedlcr给出如下关于α(T)的界的经典结论α(Pn)≤α(T)≤α(Sn)，其中Pn，Sn分别为含有n个顶点的路和星．Merris和Mass独立地证明了：α(T)=α(Sn)当且仅当T=Sn．通过重新组合由Fiedler向量所赋予的顶点的值，本给出上述不等式的新证明，并证明了：α(T)=α(Pn)当且仅当T=Pn。     

On the restriction of vector bundles to good families of curves

Summary Here we study the restriction to suitable curves of certain vector bundles on projective varieties. We handle in particular: (a) the descent of a vector bundle for the contraction of an extremal ray on a smooth 3-fold (using Mori theory); (b) the stability or semistability (in any characteristic) of certain homogeneus vector bundles on Pⁿ and their restriction to suitable subvarieties.     

On the duration of the total eclipse of a satellite of a body

This paper solves the problem of the duration of the total eclipseof a satellite of a body, provided that (a) the body is sphericalin shape and the mass distribution inside the body is sphericallysymmetrical; (b) the satellite is a very small object; (c) thesatellite's orbit around a body is circular and the satellitecan pass through the centre of its shadow; (d) a source of lightis the source of the conical body's shadow (umbra) and it doesnot change its apparent position in the sky; (e) there are noperturbations on the satellite's orbit. The solution presentedrepresents the general discussion of the problem based on utilizationof some parts of the theory of contraction mappings.     

圈的中间图pebbling数和Graham猜想

图G的一个pebbling移动是从一个顶点移走2个pebble, 而把其中的1个pebble移到与其相邻的一个顶点上. 图G 的pebbling数f(G)是最小的正整数n, 使得不论n个pebble 如何放置在G的顶点上, 总可以通过一系列的pebbling移动, 把1个pebble移到图G的任意一个顶点上. 图G 的中间图M(G) 就是在G 的每一条边上插入一个新点, 再把G 上相邻边上的新点用一条边连接起来的图. 对于任意两个连通图G和H, Graham猜测f(G\times H)\leq f(G)f(H). 首先研究了圈的中间图的pebbling 数, 然后讨论了一些圈的中间图满足Graham猜想.     

New representations of spline-wavelet decompositions

New representations of the decomposition and reconstruction operators are obtained in the cases of an infinite flow (with a grid on an open interval) and a finite flow (with a grid on a segment) for the space of (in general, not polynomial) splines of Lagrange type. Bibliography: 12 titles.     

对非线性椭圆边值问题解的存在性的研究

利用非线性增生映射值域的扰动定理 ,研究了非线性椭圆边值问题 ( @)在 L2 (Ω )中解的存在性 .( @) -△pu +g( x,u) =f a.e.在Ω中-〈v,| u|p- 2 u〉∈βx( u( x) ) a.e.在Γ上其中 f∈ L2 (Ω )给定 ,Ω RN,N 1 ,△ pu=div( | u|p- 2 u)为 P拉普拉斯算子 ,1 2 NN +1 ,v为 Γ的外法向导数 ,g:Ω× R→ R满足 Caratheodory条件 ,对 x∈ Γ,βx是正常、凸、下半连续函数 φx=φ( x,· )的次微分 ,其中 φ:Γ×R→ R.     

Verification of hyperbolicity for attractors of some mechanical systems with chaotic dynamics

Computer verification of hyperbolicity is provided based on statistical analysis of the angles of intersection of stable and unstable manifolds for mechanical systems with hyperbolic attractors of Smale–Williams type: (i) a particle sliding on a plane under periodic kicks, (ii) interacting particles moving on two alternately rotating disks, and (iii) a string with parametric excitation of standing-wave patterns by a modulated pump. The examples are of interest as contributing to filling the hyperbolic theory of dynamical systems with physical content.     

Extensions of Modules with ACC on d-annihilators

A unitary right R-module MR satisfies acc on d-annihilators if for every sequence(a_n)_n of elements of R the ascending chain AnnM(a_1)■ AnnM(a_1 a_2)■AnnM(a_1 a_2 a_3)■… of submodules of MR stabilizes. In this paper we first investigate some triangular matrix extensions of modules with acc on d-annihilators. Then we show that under some additional conditions,the Ore extension module M[x]R[x;α,δ]over the Ore extension ring R[x;α,δ] satisfies acc on d-annihilators if and only if the module MR satisfies acc on d-annihilators. Consequently, several known results regarding modules with acc on d-annihilators are extended to a more general setting.     

局部凸空间上检验函数与广义函数空间的嵌入定理及其应用

设Y是局部凸向量空间,其上装配有GaussianRadon测度γ．A（Y）（或ε（Y）是Y上检验函数空间（或με（Y）是相应的分布函数空间·我们证明了：（或με（Y）,并由此得到μA（Y）（或με（Y））上的Fourier变换公式.其中“*”表示复共轭算子,“”表示连续稠线性嵌入.进一步还得到了A（Y）（或ε（Y））上无穷维伪微分算子A是L2（Y,γ）上连续的充要条件是其共轭算子A’满足A’（L2（Y,γ）L2（Y,γ）．     

Periodic solutions of hyperbolic partial differential equations

Summary Starting with the problem of finding a mass-distribution on a sphere, admitting in each point P a density, function of the point P and of the mass contained in a certain domain depending on P, the author proves the existence and the uniqueness of the solution of (5) under assumption (1), (2), (3). As a generalization, he also studies hyperbolic partial differential equations having solutions periodic in one of the variables with period depending on the others. To Prof. BeniaminoSegre on the occasion of his 70-th birthday. Entrata in Redazione il 24 marzo 1973.     

An improved version of the out-of-kilter method and a comparative study of computer codes

The primary objectives of this paper are: (1) to present an improved formulation of the out-of-kilter algorithm; (2) to give the results of an extensive computational comparison of a code based on this formulation with three widely-used out-of-kilter production codes; (3) to study the possible sensitivity of these programs to the type of problem being solved; and (4) to investigate the effect of advanced dual start procedures on overall solution time.The study discloses that the new formulation does indeed provide the most efficient solution procedure of those tested. This streamlined version of out-of-kilter was found to be faster than the other out-of-kilter codes tested (SHARE, BSRL and Texas Water Development Board codes) by a factor of 2–5 on small and medium size problems and by a factor of 4–15 on large problems. The streamlined method's median solution time for 1500 node networks on a CDC 6600 computer is 33 seconds with a range of 33 to 35 seconds.     

1-平面图及其子类的染色

如果图G可以嵌入在平面上,使得每条边最多被交叉1次,则称其为1-可平面图,该平面嵌入称为1-平面图.由于1-平面图G中的交叉点是图G的某两条边交叉产生的,故图G中的每个交叉点c都可以与图G中的四个顶点(即产生c的两条交叉边所关联的四个顶点)所构成的点集建立对应关系,称这个对应关系为θ.对于1-平面图G中任何两个不同的交叉点c_1与c_2(如果存在的话),如果|θ(c_1)∩θ(c_2)|≤1,则称图G是NIC-平面图;如果|θ(c_1)∩θ(c_2)|=0,即θ(c_1)∩θ(c_2)=?,则称图G是IC-平面图.如果图G可以嵌入在平面上,使得其所有顶点都分布在图G的外部面上,并且每条边最多被交叉一次,则称图G为外1-可平面图.满足上述条件的外1-可平面图的平面嵌入称为外1-平面图.现主要介绍关于以上四类图在染色方面的结果.     

几何凹函数的一个重要性质及其应用

设a0,定义在[a,b]上的函数f在(a,b)上是几何凹函数,将证明F(x)=∫xaf(t)dt在(a,b)也为几何凹函数,并用实例说明其应用.     

A Numerical Method of Local Energy Decay for the Boundary Controllability of Time-Reversible Distributed Parameter Systems

This paper deals with the numerical computation of the boundary controls of linear, time-reversible, second-order evolution systems. Based on a method introduced by Russell ( Stud. Appl. Math. LII(3) (1973)) for the wave equation, a numerical algorithm is proposed for solving this type of problems. The convergence of the method is based on the local energy decay of the solution of a suitable Cauchy problem associated with the original control system. The method is illustrated with several numerical simulations for the Klein–Gordon and the Euler–Bernoulli equations in 1D, the wave equation on a rectangle, and the plate equation on a disk.     

m-循环复形范畴的Bridgeland-Hall代数的余代数结构

设A是一个遗传Abel范畴且■是A的投射对象构成的满子范畴.本文主要研究胁循环复形范畴C_m(■)的Bridgeland-Hall代数的余代数结构(其中m≥2).受Yanagida工作的启发,我们在C_m(■)上定义一个新的正合结构,由此得到了其Bridgeland-Hall代数的余代数结构.同时,证明了存在A的扩展Ringel-Hall代数到m-循环复形范畴C_m(■)的Bridgeland-Hall代数的余代数嵌入.     

Mappings preserving the idempotency of products of operators

We obtain a general form of a surjective (not assumed additive) mapping φ, preserving the nonzero idempotency of a certain product, being defined (a) on the algebra of all bounded linear operators B(X), where X is at least three-dimensional real or complex Banach space, (b) on the set of all rank-one idempotents in B(X) and (c) on the set of all idempotents in B(X). In any of the cases it turns out that φ is additive and either multiplicative or antimultiplicative.