Heping Ma

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In this paper, sharp a posteriori error estimators are derived for a class of distributed elliptic optimal control problems. These error estimators are shown to be useful in adaptive finite element approximation for the optimal control problems and are implemented in the adaptive approach. Our numerical results indicate that the sharp error estimators work(More)
We present a single-chip tuner RFIC for the newly established Chinese Mobile Multimedia Broadcasting (CMMB) standard. This mobile digital TV tuner covers the CMMB frequencies from 2.635GHz to 2.660GHz. Implemented in a 0.35um SiGe technology with 4mm 2 die size, this tuner IC achieves noise figure of 2dB, input sensitivity of-100dBm, IIP3 of 17dBm, and(More)
Hermite spectral methods are investigated for linear diffusion equations and the viscous Burgers' equation in unbounded domains. When the solution domain is unbounded, the diffusion operator no longer has a compact resolvent, which makes the Hermite spectral methods unstable. To overcome this difficulty, a time-dependent scaling factor is employed in the(More)
In this paper, we examine the discontinuous Galerkin (DG) finite element approximation to convex distributed optimal control problems governed by linear parabolic equations, where the discontinuous finite element method is used for the time discretization and the conforming finite element method is used for the space discretization. We derive a posteriori(More)
Sodium reabsorption through the epithelial sodium channel (ENaC) at the distal segment of the kidney plays an important role in salt-sensitive hypertension. We reported previously that hydrogen peroxide (H2O2) stimulates ENaC in A6 distal nephron cells via elevation of phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) in the apical membrane. Here we(More)