Minimum embedding of P3‐designs into (K4—e)‐designs

A (K₄ ? e)‐design on v + w points embeds a P₃‐design on v points if there is a subset of v points on which the K₄ ? e blocks induce the blocks of a P₃‐design. It is shown that w ≥ ¾(v ? 1). When equality holds, the embedding design is easily constructed. In this paper, the next case, when w = ¾v, is settled with finitely many exceptions. © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 352–366, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jcd.10044     

Classification of two-orbit varieties

We obtain the classification of two-orbit varieties, i.e. the normal complete complex algebraic varieties on which a reductive complex algebraic group acts with two orbits. We prove also Luna's conjecture saying that these varieties are spherical, i.e. admit a dense orbit of a Borel subgroup. Received: September 1, 2000     

Galois averages

In this paper, we introduce a notion of “Galois average” which allows us to give a suitable answer to the question: how can one extend a finite Galois extension E/F by a prime degree extension N/E to get a Galois extension N/F? Here, N/E is not necessarily a Kummer extension.     

Global solutions of the non‐linear problem describing Joule's heating in three space dimensions

The existence of global‐in‐time weak solutions to the Joule problem modelling heating or cooling in a current and heat conductive medium is proved via the Faedo–Galerkin method. The existence proof entails some a priori estimates that together with the monotonicity and compactness methods make up a main tool to prove the desired result. Under appropriate hypotheses on the data, it will be shown the boundedness in L_∞(Q_T) of the absolute temperature of the medium and of the t‐derivative of this temperature, which is achieved by means of the Gagliardo–Nirenberg theorem, the Sobolev embedding theorem and the method of Stampacchia. The paper is some extension of our investigation initiated in (Math. Meth. Appl. Sci. 1998; 23 :1275–1291). This extension includes relaxing some assumptions in (Math. Meth. Appl. Sci. 1998; 23 :1275–1291) and employing some new methods to establish the result. Copyright © 2005 John Wiley & Sons, Ltd.     

AACS-compatible multimedia joint encryption and fingerprinting: Security issues and some solutions

In this paper, a new multimedia joint encryption and fingerprinting (JEF) scheme embedded into the advanced access content system (AACS) is proposed for multimedia transmission over networks. AACS is selected because it has been jointly developed by many famous companies and has been considered as the leading technology in content access control and multimedia distribution. In this framework, many attack points exist and can be exploited to defeat it. Furthermore, multiple attack points can be combined to form multi-point collusion attacks, which also endanger the proposed system. In this paper, we address the security concerns toward AACS-compatible JEF system in its entirety and propose solutions to cope with some security threats. The contributions of this paper include: (i) applying multimedia encryption at different points to resist some attacks points; (ii) proposing rewritable fingerprint embedding (RFE) to deal with some multi-point collusion attacks; (iii) designing a perceptual security spectrum metric (PSSM) to evaluate the degree of security when multiple encryptions are applied. The feasibility of the proposed AACS-compatible JEF method is further demonstrated through simulation results.     

Embedding of analytic function spaces with given mean growth of the derivative

If ? is a positive function defined in [0, 1) and 0 < p < ∞, we consider the space ??(p, ?) which consists of all functions f analytic in the unit disc ?? for which the integral means of the derivative M _p (r, f ′) = 0 < r < 1, satisfy M _p (r, f ′) = O(? (r)), as r → 1. In this paper, for any given p ∈ (0, 1), we characterize the functions ?, among a certain class of weight functions, to be able to embedd ??(p, ?) into classical function spaces. These results complement other previously obtained by the authors for p ≥ 1. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Addendum to “A definable nonstandard enlargement”

?o?'s theorem for bounded D ‐ultrapowers, D being the ultrafilter introduced by Kanovei and Shelah [4], is established. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Linear complementarity and discounted switching controller stochastic games

The class of discounted switching controller stochastic games can be solved in one step by a linear complementarity program (LCP). Following the proof of this technical result is a discussion of a special formulation and initialization of a standard LCP pivoting algorithm which has, in numerical experiments, always terminated in a complementary solution. That the LCP algorithm as formulated always finds a complementary solution has not yet been proven, but these theoretical and experimental results have the potential to provide an alternative proof of the ordered field property for these games. Numerical experimentation with the reformulated LCP is reviewed.     

Gas composition dependence of silicon nitride used as gallium diffusion barrier during GaAs molecular beam epitaxy growth on Si complementary metal oxide semiconductor

We have measured the effect of deposition parameters upon the utility of plasma enhanced chemical vapor depositon silicon nitride as a gallium diffusions barrier during molecular beam epitaxy growth of gallium arsenide on silicon submicron complementary metal oxide semiconductor electronics. It was found that the conditions under which the silicon nitride is deposited severely impact the ability of these films to be used as a diffusion barrier, with the most critical dependence upon the silane to nitrogen gas ratio.