A new closed-form evaluation of layered medium Green'S function

A new closed-form evaluation of layered medium Green's function is proposed in this paper. The discrete complex image method (DCIM) is extended to sampling along the Sommerfeld branch cut, to capture the far field interaction. Contour deformation technique is applied to decompose the Green's function into radiation modes (branch cut integration) and guided modes (surface-wave poles). The matrix pencil method is implemented to get a closed-form solution, with the help of an alternative Sommerfeld identity. Numerical results are presented to demonstrate the accuracy of this method. © 2011 IEEE.published_or_final_versionThe 2011 IEEE International Symposium on Antennas and Propagation (APSURSI), Spokane, WA., 3-8 July 2011. In IEEE Antennas and Propagation Society. International Symposium, 2011, p. 3211-321

A new green's function formulation for modeling homogeneous objects in layered medium

A new Green's function formulation is developed systematically for modeling general homogeneous (dielectric or magnetic) objects in a layered medium. The dyadic form of the Green's function is first derived based on the pilot vector potential approach. The matrix representation in the moment method implementation is then derived by applying integration by parts and vector identities. The line integral issue in the matrix representation is investigated, based on the continuity property of the propagation factor and the consistency of the primary term and the secondary term. The extinction theorem is then revisited in the inhomogeneous background and a surface integral equation for general homogeneous objects is set up. Different from the popular mixed potential integral equation formulation, this method avoids the artificial definition of scalar potential. The singularity of the matrix representation of the Green's function can be made as weak as possible. Several numerical results are demonstrated to validate the formulation developed in this paper. Finally, the duality principle of the layered medium Green's function is discussed in the appendix to make the formulation succinct. © 1963-2012 IEEE.published_or_final_versio

An optical coherence tomography (OCT)-based air jet indentation system for measuring the mechanical properties of soft tissues

2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Modeling electrically small structures in layered medium with augmented EFIE method

Electrically small structures embedded in a planarly layered medium are modeled by the augmented electric field integral equation (EFIE) method in this paper. By separating charge as extra unknown list, and enforcing the current continuity equation, an augmented EFIE (A-EFIE) can be setup. The matrix-friendly formulation of layered medium Green's function is applied and the frequency scaling of the impedance matrix in the moment method is analyzed when the frequency tends to zero. Rank deficiency and the charge neutrality enforcement is also discussed in detail. Numerical results show that the low frequency breakdown of electrically small structures embedded in a layered medium can be effectively remedied by this A-EFIE method. © 2011 IEEE.published_or_final_versionThe 2011 IEEE International Symposium on Antennas and Propagation (APSURSI), Spokane, WA., 3-8 July 2011. In IEEE APSURSI Digest, 2011, p. 3218-322

Continuous monitoring of sonomyography, electromyography and torque generated by normal upper arm muscles during isometric contraction : sonomyography assessment for arm muscles

2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A novel implementation of discrete complex image method for layered medium Green's function

A novel implementation of discrete complex image method (DCIM) based on the Sommmerfeld branch cut is proposed to accurately capture the far-field behavior of the layered medium Green's function as a complement to the traditional DCIM. By contour deformation, the Green's function can be naturally decomposed into branch-cut integration (radiation modes) and pole contributions (guided modes). For branch-cut integration, matrix pencil method is applied, and the alternative Sommerfeld identity in terms of k z integration is utilized to get a closed-form solution. The guided modes are accounted for with a pole-searching algorithm. Both one-branch-cut and two-branch-cut cases are studied. Several numerical results are presented to validate this method. © 2011 IEEE.published_or_final_versio

Sonomyography : monitoring morphological changes of forearm muscles in actions with the feasibility for the control of powered prosthesis

Author name used in this publication: Y. P. ZhengAuthor name used in this publication: M. M. Fa. ChanAuthor name used in this publication: J. ShiAuthor name used in this publication: X. ChenAuthor name used in this publication: Q. H. Huang2006-2007 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

A new adaptive interpolation algorithm for 3D ultrasound imaging with speckle reduction and edge preservation

Author name used in this publication: Qinghua HuangAuthor name used in this publication: Yongping ZhengAuthor name used in this publication: Minhua Lu2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Study on spontaneous emission in complex multilayered plasmonic system via surface integral equation approach with layered medium Green's function

A rigorous surface integral equation approach is proposed to study the spontaneous emission of a quantum emitter embedded in a multi-layered plasmonic structure with the presence of arbitrarily shaped metallic nanoscatterers. With the aid of the Fermi's golden rule, the spontaneous emission of the emitter can be calculated from the local density of states, which can be further expressed by the imaginary part of the dyadic Green's function of the whole electromagnetic system. To obtain this Green's function numerically, a surface integral equation is established taking into account the scattering from the metallic nanoscatterers. Particularly, the modeling of the planar multilayered structure is simplified by applying the layered medium Green's function to reduce the computational domain and hence the memory requirement. Regarding the evaluation of Sommerfeld integrals in the layered medium Green's function, the discrete complex image method is adopted to accelerate the evaluation process. This work offers an accurate and efficient simulation tool for analyzing complex multilayered plasmonic system, which is commonly encountered in the design of optical elements and devices. © 2012 Optical Society of America.published_or_final_versio

Dynamic monitoring of forearm muscles using one-dimensional sonomyography system

2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe