Unidirectional evolution equations of diffusion type

This paper is concerned with the uniqueness, existence, partial smoothing effect, comparison principle and long-time behavior of solutions to the initial-boundary value problem for a unidirectional diffusion equation. The unidirectional evolution often appears in Damage Mechanics due to the strong irreversibility of crack propagation or damage evolution. The existence of solutions is proved in an $L^2$-framework by employing a backward Euler scheme and by introducing a new method of a priori estimates based on a reduction of discretized equations to variational inequalities of obstacle type and by developing a regularity theory for such obstacle problems. The novel discretization argument will be also applied to prove the comparison principle as well as to investigate the long-time behavior of solutions.     

The Convergence Rate of Fixed-Width Sequential Confidence Intervals for a Parameter of an Exponential Distribution

In this paper we consider sequential fixed-width confidence interval estimation for a parameter = aµ + b with a and b being given constants when the location parameter µ and the scale parameter of the negative exponential distribution are unknown. We investigate the rate of convergence of the coverage probability for fixed-width sequential confidence intervals of .     

Classification of companies using maximal margin ellipsoidal surfaces

We recently proposed a data mining approach for classifying companies into several groups using ellipsoidal surfaces. This problem can be formulated as a semi-definite programming problem, which can be solved within a practical amount of computation time by using a state-of-the-art semi-definite programming software. It turned out that this method performs better for this application than earlier methods based on linear and general quadratic surfaces. In this paper we will improve the performance of ellipsoidal separation by incorporating the idea of maximal margin hyperplane developed in the field of support vector machine. It will be demonstrated that the new method can very well simulate the rating of a leading rating company of Japan by using up to 18 financial attributes of 363 companies. This paper is expected to provide another evidence of the importance of ellipsoidal separation approach in credit risk analysis.     

Leakage current and paramagnetic defects in SiCN dielectrics for copper diffusion barriers

We report the properties of paramagnetic defects in SiCN films which are used as copper diffusion barriers. Electron spin resonance (ESR) signals with a g value of 2.003 and the ΔH_PP of 1.1-1.2 mT were observed for as-grown and UV-illuminated SiCN films. These characteristics of the observed ESR signals are very similar to those of the K⁰ center in N-rich silicon nitrides. We also show that a substantial increase in the leakage current occurs by exposing the SiCN films to UV illumination. We suggest that the paramagnetic defects generated by the UV illumination are responsible for this current increase.     

A collection of subgroups for the generalized Burnside ring

In this paper, we will introduce a new collection of subgroups; which induces a generalized Burnside ring. This collection arises from the normalizers of certain p-radical subgroups.     

On the Davis inequality in Banach function spaces

We give a characterization of those Banach function spaces in which the Davis inequality for martingales is valid. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Electrophilic Activation of Iodonium Ylides by Halogen-Bond-Donor Catalysis for Cross-Enolate Coupling

The umpolung alkylation of silyl enol ethers with an iodonium(III) ylide proceeds under mild conditions to afford various 1,4-dicarbonyl compounds in high yields in the presence of a halogen-bonding catalyst. Unlike typical transition-metal activation processes of such ylide precursors, which tend to proceed via carbenoid intermediates, experimental and computational studies indicate that halogen bonding (XB) between the XB donor catalyst and the iodonium ylide plays a crucial role in promoting the reaction. The identification of a compatible Bronsted base catalyst enabled the extension of this method to enols generated in situ to give the corresponding adducts in good yields.