On Codes with w-identifiable Parent Property

A code is said to be a w-identifiable parent property code (or w-IPP code for short) if whenever d is a descendant of w (or fewer) codewords, and one can always identify at least one of the parents of d. Let C be an (N, w 1, q)-code and C* an (w 1)-color graph for C. If a graph G is a subgraph of C* and consists of w 1 edges with different colors, then G is called a (w 1)-pattern of C*. In this paper, we proved that C is a w-IPP code if and only if there exists at most one vertex with color degree more than 1 in any (w 1)-pattern of C*.     

Codes From Strongly Regular （α,β）-reguli

Strongly regular (α, β)-reguli are a class of incidence structures with given conditions which were introduced by Hamilton and Mathon. We introduce two classes of codes constructed from strongly regular (α, β)-reguli within PG(k − 1, q). The codes are related with two-weight codes intimately. Foundation item: the Scientific Research Start-up Foundation of Qingdao University of Science and Technology in China (No. 0022327)     

Influence of soaking temperature on microstructure of multi-pass compression deformation for low carbon steels

The influence of soaking temperature on microstructure of high temperature multi-pass compression deformation for two low carbon steels (steel A: w _C = 0.032% and w _Mn = 0.25%; steel B: w _C = 0.165% and w _Mn = 0.38%) is studied on the thermal-mechanical simulator in order to rationalize the hot-rolling schedule of low-carbon steel and to promote the low-temperature heating technology. The results show that the microstructures of steel A are almost not affected by reducing soaking temperature, but the acicular ferrite forms in steel B when the soaking temperature is reduced from 1 200 to 1 170°C, due to its smaller initial austenite grain size according to recrystallization kinetics theory.     

On the Existence of （v, 3 × 3,λ）-Splitting Balanced Incomplete Block Design with A between 2 to 9

Let (υ, u × c, λ)-splitting BIBD denote a (υ, u × c, λ)-splitting balanced incomplete block design of order υ with block size u × c and index λ. The necessary conditions for the existence of a (υ, u × c, λ)-splitting BIBD are υ ⩾ uc, λ(υ − 1) ≡ 0 0 mod (c(u − 1)) and λυ(υ − 1) ≡ 0 mod (c ² u(u − 1)). In this paper, for 2 ⩽ λ ⩽ 9 the necessary conditions for the existence of a (υ, 3 × 3, λ)-splitting BIBD are also sufficient with one possible exception for (υ, λ) = (39, 9). Foundation item: the National Natural Science Foundation of China (No. 10771193); the Starter Foundation for the Doctors of Zhejiang Gongshang University (No. 1020XJ030517); the Natural Science Foundation of Universities of Jiangsu Province (No. 07KJB110090); the Starter Foundation for the Doctors of Nantong University (No. 07B12)     

Synchronization research of a modified time-delayed multi-agent network model

The synchronization of time-delayed multi-agent networks with connected and directed topology is studied. Based on the correlative work about the agent synchronization, a modified model is presented, in which each communication receiver is distributed a delay τ. In addition, a proportional term k is introduced to modulate the delay range and to guarantee the synchronization of each agent. Two new parameters mentioned above are only correlative to the network topology, and a theorem about their connections is derived by both frequency domain method and geometric method. Finally, the theoretical result is illustrated by numerical simulations. Foundation item: the National Natural Science Foundation of China (No. 70571017) and the Research Foundation from Provincial Education Department of Zhejiang of China (No. 20070928)     

General admissibility for linear estimators of multivariate random regression coefficients and parameters with respect to a restricted parameter set

This paper considers the linear model effected by random disturbance, Y = XB + ɛ, where $ \left[ \begin{gathered} B \hfill \\ \varepsilon \hfill \\ \end{gathered} \right] \sim \left( {\left[ \begin{gathered} A\Theta \hfill \\ 0 \hfill \\ \end{gathered} \right],V \otimes \Sigma } \right) $ \left[ \begin{gathered} B \hfill \\ \varepsilon \hfill \\ \end{gathered} \right] \sim \left( {\left[ \begin{gathered} A\Theta \hfill \\ 0 \hfill \\ \end{gathered} \right],V \otimes \Sigma } \right) , and Θ ^T A ^T X ^T NXAΘ ⩽ Σ. It gives a definition for general admissible estimator of a linear function SΘ + GB of random regression coefficients and parameters. The necessary and sufficient conditions for LY and LY + C to be general admissible estimators of SΘ + GB in the class of both homogenous and non-homogenous linear estimators are obtained. The conclusion is not dependent of whether or not SΘ +GB is estimable.     

两类图的算术标号

对于一个（p，g）图G，如果存在一个v（G）到非负整数集N0的一个映射以称为顶点标号）满足：（1）f（u）≠f（v），其中u≠v，且u，v∈V，（c）；（2）{f（u）＋f（v）｜uv∈E（G））={k，k＋d，…，k＋（g-1）d），称图G为（k，d）-算术图。证明了图Fm．4是（d，2d）-算术图和图Fm．6是（d，3d）-算术图。     

若干合成图的星全染色

简单图G和H的合成图是指具有顶点集V（G）×V（H）的简单图G[H],它的顶点（u,v）和另一个顶点（u,v＇）相邻当且仅当或者uu＇∈E（G）,或者“u=u’且vv’∈E（H）．文中研究了n＋1阶简单图G与m阶简单图H的合成图的星全染色,其中G为Wn。,扇Fm或星Sn．得到以下结果：（1）若△（H）=2且n≥4,m≥5,则G[H]的星全色数为（2n＋1）m;（2）若x（H）=△（H）=m-1且n,m≥4,则G[H]的星全色数为2（n＋1）m-1．     

关于图的集控制数

设G是一个图,如果V(G)能划分为t个两两不交的控制集Dt(i=1,2,…,t),则称G有t-控制集划分.图G的集控制数定义为d(G)=max{ t|G有t-控制集划分}.该文主要研究乘积图与联图的集控制问题,给出其集控制数的界限,并确定一些特殊图的集控制数.     

The Dimensions of Graphs and Constructions of Their Bases

IntroductionGraph G,considered in this paper,is finiteand simple with vertex set V ( G) and edge setE( G) .Let d( x,y) denote the distance between xand y in G and W={w1,w2 ,…,wk}denote the or-dered set of V( G) .For any given v∈V( G) ,therepresentation of v with respect to W is the k- vec-tor:r( v| W) ={d( v,w1) ,d( v,w2 ) ,…,d( v,wk) }.The ordered set W is called a resolving set of G ifr( u| W) =r( v| W) implies that u=v for all pairs{u,v}of vertices of G. A resolving set of G with…     

A two-step outlier removal procedure for surface reconstruction

Outliers in point clouds affect the performance of surface reconstruction directly. Most of outlier removal methods just remove those outliers far away from the real surface and are only applied to handle watertight surface. In this paper, a two-step outlier removal procedure is proposed to filter the point clouds acquired from the gray code and line-shifting technique. The first step is to remove the outliers far away from the real surface. Some feature points are extracted from the point clouds to construct an initial surface. The points with distances to the initial surface greater than a given threshold are removed as distant outliers. The retained points are linked into lines in each structured light sheet using their Voronoi diagrams. Some of lines which are very close to the real surface are removed as near outliers in the second step. The experimental results show that the proposed method is very effective in removing outliers for surface reconstruction. Foundation item: the National Natural Science Foundation of China (No. 30470488)     

Study on rotational stabilization in a laser tracking system

The high rolling speed of a missile heavily affects the stabilizing capability of the inertial platform in the laser tracking system (LTS) of the missile. In this paper, a rotational stabilizing platform (RSP) and a fuzzy-PID controller is designed to stabilize the inertial platform. This controller integrates the advantages of both fuzzy controller and classic PID controller. A comparison study is carried out to illustrate the advantages of the proposed fuzzy-PID controller over the classic PID controller. Numerical results indicate that the fuzzy-PID controller outperforms the classic one in effectively handling nonlinear disturbances and quickly stabilizing the inertial platform at the sudden change of missile rolling speed. Foundation item: the China Aerospace Science and Innovation Foundation (No. 06CASC0407)     

Properties and electronic structure of iron under pressure up to 30GPa

The properties and electronic structure of Fe under pressures of 0–30GPa have been studied by first principles employing the density functional theory (DFT), the ultra-soft pseudo-potentials (USPP) and the generalized gradient approximation (GGA). The calculating results show that there is a structural transition from magnetic body-centered cubic (bcc) to nonmagnetic hexagonal-close-packed (hcp) structure for Fe around 11GPa pressure. There is a pseudogap both in the density of states (DOS) for bcc and hcp Fe. The pseudogap of bcc Fe is deeper and wider than that of hcp Fe. The elastic modulus is obtained by Voigt-Reuss-Hill averaging scheme. The results indicate that the elastic properties of bcc Fe enhance with pressure except for elastic stiffness constant C ₁₁, shear modulus G and elastic modulus E at the transition pressure, while the elastic properties of hcp Fe increase linearly with pressure. Magnetic bcc Fe is ductile, and hcp Fe becomes ductile from brittle around 25GPa.     

Efficient democratic group signatures with threshold traceability

Democratic group signature (DGS) is a group-oriented primitive with great flexibilities, i.e., no group manager, anonymity, and traceability. In a DGS scheme with (t, n)-threshold traceability, any subset of not less than t members can jointly reveal the identity of the signer while preserving security even in the presence of an active adversary can corrupt up to t − 1 group members. This paper proposes an efficient DGS scheme. We use publicly verifiable secret sharing (PVSS) to distribute the trapdoor via which the real signer is revealed. The computation cost and communication overhead of our DGS signatures are greatly reduced, compared with the existing work. For example, the size of the resulting signature contains only 2n + 1 elements of Z _q , except the PVSS output.     

A.Kotzig关于自补图的一个问题

A.Kotzig提出这样一个问题:对于任意正则自补图G,是否存在G的一个自补置换s,s是{1,4,4,...,4}型,定理1否定地回答了这个问题.     

图的反符号全控制数

设G=(VE)是一个无孤立顶点的图,一个函数f:V{-1,+1}称为图G的一个反符号全控制函数,如果f(N(v))≤1对任何点v V(G)成立。图G的反符号全控制数记为γrst(G)=max{f(V)|f为图G的一个反符号全控制函数}。该文对图的反符号全控制函数进行了研究,获得了一般图的反符号全控制数的若干界限,确定了完全图和完全二部图的反符号全控制数。     

ON THE EXISTENCE OF THE h-RESTRICTED EDGE CONNECTIVITY OF A GRAPH

IntroductionLet G=(V,E) be a finite,simple and undi-rected graph with vertex set V and edge set E.We' ll follow the terminology and notation of Ref.[1 ]and terms not defined here can be found inRefs.[1 ,2 ].A set S of edges of G is called an edgedisconnecting set if G - S is disconnected. Theusual edge connectivityλ(G) of G is the minimumcardinality over the all edge disconnecting sets ofG.Note that,in the above definition,absolutelyno conditions or restrictions are imposed either onthe…     

关于冠图与queens-图的若干结果

文献[3]引入了queens-图的概念.一个(0,1)-矩阵A的queens-图的点集对应于A中的1,两个点邻接当且仅当它们对应的1在A的同一条线上.一个基本问题是判断哪些图是queens-图,该文证明了两类冠图是queens-图.     

Code-aided interference suppression in direct sequence spread spectrum systems with eigenvector sign spreading code

For direct sequence spread spectrum (DSSS) communication systems suffering interference, it is known that code-aided interference suppression technique outperforms all of the previous linear or nonlinear methods. In this paper, we proposed an improved code-aided technique which can improve the system performance greatly by using the eigenvector sign (EVS) spreading sequence which depends on the statistical characteristics of the interference and the thermal noise. Foundation item: the National Natural Science Foundation of China (No. 60772100)     

Joint distortion model for progressive image transmission using error correcting arithmetic codes

A novel joint source channel distortion model was proposed, which can essentially estimate the average distortion in progressive image transmission. To improve the precision of the model, the redundancy generated by a forbidden symbol in the arithmetic codes is used to distinguish the quantization distortion and the channel distortion, all the coefficients from the first error one to the end of the sequence are set to be a value within the variance range of the coefficients instead of zero, then the error propagation coming from the entropy coding can be essentially estimated, which is disregarded in the most conventional joint source channel coding （JSCC） systems. The precision of the model in terms of average peak-signal-to-noise has been improved about 0.5 dB compared to classical works. An efficient unequal error protection system based on the model is developed, and can be used in the wireless communication systems.