Numerical solutions of 2× 2 semilinear systems of elliptic boundary value problems, whose nonlinearities are of quasimonotone nondecreasing, quasimonotone nonincreasing, or mixed quasimonotone types, are computed. At each step of the (quasi) monotone iteration, the solution is represented by a simple-layer potential plus a domain integral; the simple-layer density is then discretized by boundar...

We deal with a system of Lotka-Volterra competition-diffusion equations on R, which is a competing two species model with diffusion. It is known that the equations allow traveling waves with monotone profile. In this article we prove the existence of an entire solution which behaves as two monotone waves propagating from both sides of x-axis, where an entire solution is meant by a classical sol...

We establish new existence results for the Einstein constraint equations for mean extrinsic curvature arbitrarily far from constant. The results hold for rescaled background metric in the positive Yamabe class, with freely specifiable parts of the data sufficiently small, and with matter energy density not identically zero. Two technical advances make these results possible: A new topological f...

This paper derives the optimal debt ratio and dividend payment strategies for an insurance company. Taking into account the impact of reinsurance policies and claims from the credit derivatives, the surplus process is stochastic that is jointly determined by the reinsurance strategies, debt levels, and unanticipated shocks. The objective is to maximize the total expected discounted utility of d...

general, any n-sequence determines a multiset of (= n!/k!(n-k)!) k-sequences. "J Suppose, conversely, that we are given a multiset 01 k-sequences. Does that multiset come from some sequence? If so, is the source sequence unique? Such questions are reminiscent of the problem of reconstructing graphs from vertex-deleted sub raphs, which has received a great deal of attention in the last twent yea...

The paper deals with a new technique of fragile image watermarking. Proposed technique exploits inter-subband dependencies in order to minimize the influence of inserted watermark on the host image quality. Using the unique watermark based on the low-frequency subband, proposed scheme is resistant against attacks based on series of images analysis. Tampering detection ability of the proposed te...

Let G be an additive finite abelian group with exponent exp(G). Let S = g1 · . . . · gl be a sequence over G and k(S) = ord(g1)+· · ·+ord(gl) be its cross number. Let η(G) (resp. t(G)) be the smallest integer t such that every sequence of t elements (repetition allowed) from G contains a non-empty zero-sum subsequence T of length |T | ≤ exp(G) (resp. k(T ) ≤ 1). It is easy to see that t(G) ≥ η(...

Classification of blocks of subband samples according to their energy and variable bit allocation within the subsequent classes has demonstrated considerable gains in coding efficiency. The gains due to classification increase as smaller blocks are used; however, this increases the overheads for transmitting the classification information. In this paper, a quadtree based method is proposed. Thi...

The use of subband coding on image data is discussed. An overviev~ of siibbai~d coding is given. Advantages of subbanding for browsing and progressive resol~itiori ar-e presented. Implementations for lossless and lossy coding are discussed. Algorithn~ considerations and simple implementations of subband systems are given.