‘The Diversity of Expression and the Wondrous Power of the Art of Photography’ in the Albums of Richard Cockle Lucas

From 1859 to 1878 the British sculptor Richard Cockle Lucas assembled at least sixteen albums containing photographs of himself in numerous guises, ranging from Shakespearean roles to embodiments of specific emotions. Lucas utilised the practice of dressing up in front of the camera in conjunction with the album format as an ongoing means of experimenting with photography’s capacity to convey human expression, and as an extension of his concerns as a sculptor. Lucas’s albums, which also include photographs of his work in sculpture, represent the first sustained pursuit of photographic self-depiction in such a wide range of roles. Read in conjunction with Lucas’s own writings on expression in photography and sculpture, the albums reveal how Lucas viewed photographic self-portraiture as a form of ‘living sculpture’ to be enacted before the camera.     

基于原模图的8环QC-LDPC码构造方法

针对当前准循环低密度奇偶校验(Quasi-Cyclic Low-Density Parity-Check, QC-LDPC)码存在短环及纠错性能不够好的问题,基于原模图提出一种新颖的QC-LDPC码构造方法。该方法选择码长码率可灵活调整的原模图作为基矩阵,再结合具有特殊性质的卢卡斯数列和等差数列,通过原模图的低译码门限和数列的特殊性质,构造校验矩阵环长至少为8,且所需存储空间少,易于硬件实现。仿真结果表明：该方法构造的PLA-QC-LDPC(2400,1200)码与同等码长码率中基于卢卡斯数列和最大公约数序列的可快速编码的非规则LG-QC-LDPC码、基于素数和乘法表构造的PM-QC-LDPC码以及基于原模图和消除基本陷阱集的非规则PL-QC-LDPC码相比,净编码增益均有一定程度的提高。     

广义高阶Fibonacci数和Lucas数的计算公式

给出了广义的Fibonacci数和Lucas数一般定义,得出了几个恒等式,并得到了经典Fi-bonacci数和Lucas数的计算公式.     

关于Lucas数的一类行列式的计算

研究了一类由Lucas数组成的行列式Ln(m,k，l)的计算问题，证明了当m≤n-2时有恒等式Ln(m，k，l)=0，当m=n-1时给出了一个计算其值的公式。     

Virtual Corpses,Figural Sections and Resonant Fields

The ‘figural section’ is one of the most potent but under used forms of architectural communication. It enables slices, extrusions, fragments and surfaces of buildings to become the media of the non-expressive and deadpan. Here Sean Griffiths of FAT looks at Venturi Scott Brown's influence in the development of the figural section and how it has evolved into a key trope in his practice's own work. Copyright © 2011 John Wiley & Sons, Ltd.     

On strong Dickson pseudoprimes

It is known that the Lucas sequenceV _n(,c)=aⁿ + bⁿ,a, b being the roots ofx ² – x + c=0 equals the Dickson polynomial .^n–2i Lidl, Müller and Oswald recently defined a number b to be a strong Dickson pseudoprime to the parameterc (shortlysDpp(c)) if [itg_n(b, c)b modn for all b. These numbers seem to be very appropriate for a fast probabilistic prime number test. In generalizing results of the above mentioned authors a criterion is derived for an odd composite number to be ansDpp(c) for fixedc. Furthermore the optimal parameterc for the prime number test is determined.     

替代LUC系统的一种新公钥系统

新公钥系统是利用Dickson的另外两类多项式,替代生成LUC系统的Lucas序列,利用一个新的算法构造的公钥系统。与LUC系统相比,新公钥系统具有相同的安全性,但是计算量减少,效率相对提高,比LUC系统实用性更强。     

Primality testing of large numbers in Maple

Primality testing of large numbers is very important in many areas of mathematics, computer science and cryptography, and in recent years, many of the modern primality testing algorithms have been incorporated in Computer Algebra Systems (CAS) such as Axiom and Maple as a standard. In this paper, we discuss primality testing of large numbers in Maple V Release 3, a Maple version newly released in 1994. Our computation experience shows that the Maple primality testing facility isprime, based on a combined use of a strong pseudoprimality test and a Lucas test, is efficient and reliable.     

关于指数Diophantine方程x^2＋2^（2m）=y^n

运用Lucas数本原素因数存在性的结果讨论方程x^2＋2^2m=y^n的正整数解（x,y,m,n）,证明了该方程仅有正整数解（x,y,m,n）=（2^（n-1）/2,2^r（rs-1）/2,s）和（2^3k.11,2^2k.5,3k＋1,3）适合n〉2,其中r和s是适合s〉2的正奇数,k是非负整数.