We analyze the security of the SEED block cipher against di erential attacks. SEED is a 16-round Feistel cipher developed by the Korea Information Security Agency. The SEED proposers estimated their cipher against di erential cryptanalysis in a self-estimation document and found a six-round di erential characteristic with probability 2 130 . We present an improved method of examining the di ere...

In this paper, the problem of the stability analysis for neutral delay-di€ erential systems with nonlinear perturbations is investigated. Using the L yapunov method, we present new su cient conditions for the stability, in terms of the linear matrix inequality (LMI), which can be easily solved by various convex optimization algorithms. Numerical examples are given to illustrate the application...

We consider cyclic nearest neighbor systems of di erential delay equations, in which the coupling between neighbors possesses a monotonicity property. Using a discrete (integer-valued) Lyapunov function, we prove that the Poincar e-Bendixson theorem holds for such systems. We also obtain results on piecewise monotonicity and stability of periodic solutions of such systems.

-260 Archimedes mathematically works out the principle of the lever and discovers the principle of buoyancy 60 Hero of Alexandria writes Metrica, Mechanics, and Pneumatics 1490 Leonardo da Vinci describes capillary action 1581 Galileo Galilei notices the timekeeping property of the pendulum 1589 Galileo Galilei uses balls rolling on inclined planes to show that di erent weights fall with the sa...

In this paper we deene a compositional semantics for a generalized composition operator on logic programs. Static and dynamic inheritance as well as composition by union of clauses can all be obtained by specializing the general operator. The semantics is based on the notion of diierential programs, logic programs annotated with declarations that establish the programs' external interfaces.

First order neutral di¤erential equations are studied and su‰cient conditions are derived for every solution to be oscillatory. Our approach is to reduce the oscillation of neutral di¤erential equations to the nonexistence of eventually positive solutions of non-neutral di¤erential inequalities. Our results extend and improve several known results in the literature.

We consider an optimal stopping problem for a Hilbert-space valued di usion. We prove that the value function of the problem is the unique viscosity solution of an obstacle problem for the associated parabolic partial di erential equation in the Hilbert space. The results are applied to investigate the pricing of American interest rate options in the lognormal Heath-Jarrow-Morton model of yield...

Multigrid methods originated earlier this century, in the personnel computing era. Someone who needed to compute an approximation to the solution of a partial di erential equation during that era would ll a room with people. After using very simple mechanical calculators to compute parts of the approximation, these people would pass their parts to the other people in the room who needed them. E...

Hybrid transition systems in their full generality describe continuous behaviour by a set of equations in each mode { an algebraic or di erential equation for each state variable in terms of inputs and other state variables. Each discrete transition may be taken according to a (non-deterministic) time constraint. In this paper we restrict this model to time-deterministic discrete transitions. T...

| Four schemes for linearizing the transconductance of the basic di erential pair in subthreshold CMOS are examined. They are: source degeneration via (1) diode-connected transistors, (2) a single di usor and (3) symmetric di usors, and (4) multiple asymmetric di erential pairs. We derive equations for the di erential output current for each linearizing technique. We apply a maximally at optimi...