Hadamard (or complete $CAT(0)$) spaces are complete, non-positive curvature, metric spaces. Here, we prove a nonlinear ergodic theorem for continuous non-expansive semigroup in these spaces as well as a strong convergence theorem for the commutative case. Our results extend the standard non-linear ergodic theorems for non-expansive maps on real Hilbert spaces, to non-expansive maps on Ha...

A new formulation for the non-dimensional dynamic influence function method, which was developed by the authors, is proposed to efficiently extract eigenvalues and mode shapes of clamped plates with arbitrary shapes. Compared with the finite element and boundary element methods, the non-dimensional dynamic influence function method yields highly accurate solutions in eigenvalue analysis problem...

Micro-Channel Heat Sink is a heat exchanger which is used to control the temperature of electronic devices with high heat flux. A comprehensive thermal model for the micro-channels should include three dimensional conduction analysis in the solid body together with three dimensional developing fluid flow as well as heat transfer analyses in the fluid section. This paper reports on a research ...

We investigate how accurate different methods of the spectral line shape analysis work in two-dimensional correlation spectroscopy (2D CS) for systems with non-gaussian dynamics. A direct link is established between the frequency dependent correlation functions and a number of line shape metrics. Two model systems are constructed mimicking a typical molecular system with conventional gaussian a...

A novel method for the design of two-dimensional (2-D) and three-dimensional (3-D) arrays with frequency invariant beam patterns is proposed. By suitable substitutions, the beam pattern of a 2-D or 3-D arrays can be regarded as the 3-D or 4-D Fourier transform of its spatial and temporal parameters. Since frequency invariance can be easily imposed in the Fourier domain, a simple design method i...

The 3ω method for measurement of thermal conductivity of a solid usually consists of a strip heater above a substrate, and the method is based on an approximate solution of the heat conduction problem in which the heater thickness is neglected. We establish a two-dimensional heat conduction model for the heater-on-substrate 3ω method which takes into account the finite thickness of the heater. ...

The shock wave–turbulent boundary layer interaction over a compression corner is studied using global stability analysis (GSA) and resolvent based on separation of scales between the low-frequency, large-scale motions turbulent fluctuations. GSA identifies leading stationary mode, which becomes globally unstable as ramp angle beyond critical value. For stable flows, captures two-dimensional thr...