Hongwei Cheng

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We describe a wideband version of the Fast Multipole Method for the Helmholtz equation in three dimensions. It unifies previously existing versions of the FMM for high and low frequencies into an algorithm which is accurate and efficient for any frequency, having a CPU time of O(N) if low-frequency computations dominate, or O(N logN) if high-frequency(More)
OBJECTIVE We undertook this study to quantitate differences in the degree of calcification between symptomatic and asymptomatic plaques removed at carotid endarterectomy (CEA) and to determine associated extent of plaque macrophage infiltration, a histopathologic feature of plaque instability. METHODS CEA plaques (n = 48) were imaged at 1.25-mm intervals(More)
A long-standing area of materials science research has been the study of electrostatic, magnetic, and elastic fields in composites with densely packed inclusions whose material properties differ markedly from that of the background. While powerful tools exist for dilute suspensions, accurate calculations in the close-to-touching case have been carried out(More)
OBJECTIVE To identify features on B-mode ultrasonography (US) prevalent in symptomatic plaques and correlate these findings with histopathologic markers of plaque instability. METHODS Carotid endarterectomy (CEA) plaques from symptomatic and asymptomatic patients with critical stenoses (>70%) were qualitatively assessed using preoperative B-mode US for(More)
The synthesis of a multiblock poly(ether ester urethane)s comprising poly(ε-caprolactone), poly(ethylene glycol), and poly(propylene glycol) segments is described. We found that this polymer possessed a critical thermo-gelation concentration of 4wt%. Molecular characterization of the polymer was performed in terms of molecular weight determination, chemical(More)
The inflammatory response plays a significant role in neuronal cell death and functional deficits after Traumatic brain injury (TBI). Importantly, anti-inflammatory agents have neuroprotective effects. To date, however, no studies have investigated the neuroprotective effects of Saikosaponin a (SSa) after TBI. In the present study, rats with controlled(More)
Wireless link quality prediction (LQP) is the foundation for proactive operations and is therefore a key technique in alleviating network performance degradation. However, accurate LQP is difficult because of the dynamic nature of wireless environments. A recent study found that fluctuations in intermediate quality links often show dynamics on a sub-second(More)