H2/H∞ output information-based disturbance attenuation for differential linear repetitive processes

Repetitive processes propagate information in two independent directions where the duration of one is finite. They pose control problems that cannot be solved by application of results for other classes of 2D systems. This paper develops controller design algorithms for differential linear processes, where information in one direction is governed by a matrix differential equation and in the other by a matrix discrete equation, in an H2/H∞ setting. The objectives are stabilization and disturbance attenuation, and the controller used is actuated by the process output and hence the use of a state observer is avoided

Ear care: an update for nurses (part 1)

A healthy ear is vital not just for hearing, but for balance and for full engagement with the community. In the first of two articles, Kat Millward reviews the anatomy of the ear, outlines methods of dealing with cerumen, and discusses methods of assessment and diagnosis Our ears are essential for both hearing and balance. Up to 4% of the population will have difficulties with their ears relating to impacted cerumen and many of them will present in primary care with ear discomfort or hearing difficulties. In the first of two articles, we review the anatomy and physiology of the ear and cerumen production, followed by a discussion of the key aspects of making an assessment using the SOAP (Subjective, Objective, Assessment, Plan) mnemonic

A study of anode corrosion and its influence on cathode purity in electrolytic zinc production

Anode corrosion is a problem with which electrolytic zinc producers have been concerned from the beginning of the practice. It has been attacked here from the view of modern practice, using alloyed anodes --Introduction, page 1

The Puromycin Route to Assess Stereo- and Regiochemical Constraints on Peptide Bond Formation in Eukaryotic Ribosomes

We synthesized a series of puromycin analogues to probe the chemical specificity of the ribosome in an intact eukaryotic translation system. These studies reveal that both d-enantiomers and β-amino acid analogues can be incorporated into protein, and provide a quantitative means to rank natural and unnatural residues. Modeling of a d-amino acid analogue into the 50S ribosomal subunit indicates that steric clash may provide part of the chiral discrimination. The data presented provide one metric of the chiral and regiospecificity of mammalian ribosomes

A geometric theory for 2-D systems including notions of stabilisability

In this paper we consider the problem of internally and externally stabilising controlled invariant and output-nulling subspaces for two-dimensional (2-D) Fornasini–Marchesini models, via static feedback. A numerically tractable procedure for computing a stabilising feedback matrix is developed via linear matrix inequality techniques. This is subsequently applied to solve, for the first time, various 2-D disturbance decoupling problems subject to a closed-loop stability constraint

Detectability subspaces and observer synthesis for two-dimensional systems

The notions of input-containing and detectability subspaces are developed within the context of observer synthesis for two-dimensional (2-D) Fornasini-Marchesini models. Specifically, the paper considers observers which asymptotically estimate the local state, in the sense that the error tends to zero as the reconstructed local state evolves away from possibly mismatched boundary values, modulo a detectability subspace. Ultimately, the synthesis of such observers in the absence of explicit input information is addressed