Minimal realizations of three-port resistive networks

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Realization of biquadratic impedances with at most four elements

This paper considers the realizability problem of biquadratic impedances with at most four elements. To solve the problem, the necessary and sufficient realizability condition for no more than three elements is obtained by some topological properties derived previously. Furthermore, the constraints on the possible realizations are used to find out the networks which can cover all the cases, and they are classified as several quartets. Finally, investigating one of the networks in each quartet yields the necessary and sufficient condition for a network to be realized with at most four elements.published_or_final_versio

Generalized series-parallel RLC synthesis without minimization for biquadratic impedances

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Realization of a special class of admittances with one damper and one inerter for mechanical control

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Adaptive group consensus of coupled harmonic oscillators with multiple leaders

In this paper, we investigate the group consensus of coupled harmonic oscillators with multiple leaders in an undirected fixed network. Unlike many existing algorithms for group consensus of multi-agent systems or cluster synchronization of complex dynamical networks, which require global information of the underlying network such as the eigenvalues of the coupling matrix or centralized control protocols, we propose a novel decentralized adaptive group consensus algorithm for coupled harmonic oscillators. By using the decentralized adaptive group consensus algorithm and without using any global information of the underlying network, all agents in the same group asymptotically synchronize with the corresponding leader even when only one agent in each group has access to the information of the corresponding leader. Numerical simulation results are presented to illustrate the theoretical results. © 2012 IEEE.published_or_final_versio

Realizability of n-port resistive networks with 2n terminals

In this paper, we consider the realizability problem of n-port resistive networks containing 2n terminals. A necessary and sufficient condition for any real symmetric matrix to be realizable as the admittance of an n-port resistive network containing 2n terminals is obtained. The condition is based on the existence of a parameter matrix. We then focus on a three-port resistive network containing six terminals. A necessary and sufficient condition is derived for any real symmetric matrix to be realizable as the admittance of a three-port resistive network containing six terminals and at most five positive elements, whose topological structure is properly restricted. © 2013 IEEE.published_or_final_versio

A chiral HPLC-MS/MS method for simultaneous quantification of warfarin enantiomers and its major hydroxylation metabolites of CYP2C9 and CYP3A4 in human plasma

Warfarin is an oral anticoagulant that requires frequent therapeutic drug monitoring due to a narrow therapeutic window, considerable interindividual variability in drug response, and susceptibility to drug-drug and drug-diet interactions. Enantiomeric separation and quantification of warfarin enantiomers and clinically important major hydroxylation metabolites are essential for drug interaction studies and phenotypic characterization of CYP2C9 and CYP3A4, the major Cytochrome P450 (CYP) enzymes involved in warfarin metabolism. Here, we describe the development and validation of a chiral high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)-based quantification of R-warfarin, S-warfarin, S-7-hydroxywarfarin (the major CYP2C9metabolite) and (9R; 10S)-10-hydroxywarfarin (the CYP3A4 metabolite) in human plasma. Simple protein precipitation-based extraction showed good recovery of analytes (82.9 - 96.9%). The developed method exhibited satisfactory intra-day and inter-day accuracy and precision. The lower limits of detection were 0.25nM (or ~0.08 ng/ml) for the warfarin enantiomers and 0.1nM (or ~0.04 ng/mL) for S-7-hydroxywarfarinand (9R; 10S)-10-hydroxywarfarin using only 50μL plasma during extraction. The validated method was successfully applied to analyze plasma samples obtained from a healthy human subject who enrolled in a clinical drug interaction study involving warfarin