J. S. J. Chen

Learn More
Noninvasive, easy-to-use and accurate measurements of wall shear stress (WSS) in human blood vessels have always been challenging in clinical applications. Echo particle image velocimetry (Echo PIV) has shown promise for clinical measurements of local hemodynamics and wall shear rate. Thus far, however, the method has only been validated under simple flow(More)
Abrupt climate change is a ubiquitous feature of the Late Pleistocene epoch. In particular, the sequence of Dansgaard-Oeschger events (repeated transitions between warm interstadial and cold stadial conditions), as recorded by ice cores in Greenland, are thought to be linked to changes in the mode of overturning circulation in the Atlantic Ocean. Moreover,(More)
To achieve fast turn around, appropriate performance and efficient silicon area in ASIC design, it is desirable to have the capability of generating new customized cells overnight. A design rule independent cell compiler which is capable of generating nearly optimal layout and all the desirable user interfaces such as automatic place and route database,(More)
An examination of load deflection (bulge) testing of coated and uncoated membranes by analytical and finite element methods was undertaken. The key parameters in the load-deflection behavior of a membrane were non-dimensionalized and examined to illustrate how to design test structures for materials systems of interest. Experimental and modelling procedures(More)
A solar cell relies on its ability to turn photons into current. Because short wavelength photons are typically absorbed near the top surface of a cell, the generated charge carriers recombine before being collected. But when a layer of quantum dots (nanoscale semiconductor particles) is placed on top of the cell, it absorbs short wavelength photons and(More)
Retrieval of the bianisotropic metamaterial The retrieval methods to compute the effective permittivity and permeability of metamaterials published so far deal with isotropic permittivity and permeability. However, it is known already that the metamaterials are intrinsically anisotropic because of the orientations of the rings and rods in space, and that(More)
The 6 January 1997 and 7 April 1997 halo coronal mass ejections (CMEs) were associated with interplanetary magnetic clouds observed by WIND that led to increased geomagnetic storm activity as indicated by the hourly Dst index. A recently developed storm-prediction method is retrospectively applied to these two solar wind (SW) structures. The results are(More)
Study and characterization of left-handed metamaterials Many of the basic properties of left-handed (LH) media are in constrast to those typically encountered in right-handed media. For example, using a rigourous plane wave analysis of propagation and transmission into a dispersive LH medium from a RH medium, we show that power refracts at a negative angle,(More)