'King Lear' by William Shakespeare

Critical Edition, with full sources, notes and commentary, of William Shakespeare, King Lear.

On discrimination algorithms for ill-posed problems with an application to magnetic tomography

In this paper we explore classification techniques for ill-posed problems. Two classes are linearly separable in some Hilbert space X if they can be separated by a hyperplane. We investigate stable separability, i.e. the case where we have a positive distance between two separating hyperplanes. When the data in the space Y is generated by a compact operator A applied to the system states ∈ X, we will show that in general we do not obtain stable separability in Y even if the problem in X is stably separable. In particular, we show this for the case where a nonlinear classification is generated from a non-convergent family of linear classes in X. We apply our results to the problem of quality control of fuel cells where we classify fuel cells according to their efficiency. We can potentially classify a fuel cell using either some external measured magnetic field or some internal current. However we cannot measure the current directly since we cannot access the fuel cell in operation. The first possibility is to apply discrimination techniques directly to the measured magnetic fields. The second approach first reconstructs currents and then carries out the classification on the current distributions. We show that both approaches need regularization and that the regularized classifications are not equivalent in general. Finally, we investigate a widely used linear classification algorithm Fisher's linear discriminant with respect to its ill-posedness when applied to data generated via a compact integral operator. We show that the method cannot stay stable when the number of measurement points becomes large.

‘The Making of the Book’: Roy Fisher, the Circle Press and the poetics of book art

Between 1972 and 2001, the English late-modernist poet Roy Fisher provided the text for nine separate artist's books produced by Ron King at the Circle Press. Taken together, as Andrew Lambirth has written, the Fisher-King collaborations represent a sustained investigation of the various ways in which text and image can be integrated, breaking the mould of the codex or folio edition, and turning the book into a sculptural object. From the three-dimensional pop-up designs of Bluebeard's Castle (1973), each representing a part of the edifice (the portcullis, the armoury and so on), to ‘alphabet books’ such as The Half-Year Letters (1983), held in an ingenious french-folded concertina which can be stretched to over a metre long or compacted to a pocketbook, the project of these art books is to complicate their own bibliographic codes, and rethink what a book can be. Their folds and reduplications give a material form to the processes by which meanings are produced: from the discovery, in Top Down, Bottom Up (1990), of how to draw on both sides of the page at the same time, to the developments of The Left-Handed Punch (1987) and Anansi Company (1992), where the book becomes first a four-dimensional theatre space, in which a new version of Punch and Judy is played out by twelve articulated puppets, and then a location for characters that are self-contained and removable, in the form of thirteen hand-made wire and card rod-puppets. Finally, in Tabernacle (2001), a seven-drawer black wooden cabinet that stands foursquare like a sculpture (and sells to galleries and collectors for over three thousand pounds), the conception of the book and the material history of print are fully undone and reconstituted. This paper analyses how the King-Fisher art books work out their radically material poetics of the book; how their emphasis on collaboration, between artist and poet, image and text, and also book and reader – the construction of meaning becoming a co-implicated process – continuously challenges hierarchies and fixities in our conception of authorship; and how they re-think the status of poetic text and the construction of the book as material object.

Classification and fault detection methods for fuel cell monitoring and quality control

In this paper, various types of fault detection methods for fuel cells are compared. For example, those that use a model based approach or a data driven approach or a combination of the two. The potential advantages and drawbacks of each method are discussed and comparisons between methods are made. In particular, classification algorithms are investigated, which separate a data set into classes or clusters based on some prior knowledge or measure of similarity. In particular, the application of classification methods to vectors of reconstructed currents by magnetic tomography or to vectors of magnetic field measurements directly is explored. Bases are simulated using the finite integration technique (FIT) and regularization techniques are employed to overcome ill-posedness. Fisher's linear discriminant is used to illustrate these concepts. Numerical experiments show that the ill-posedness of the magnetic tomography problem is a part of the classification problem on magnetic field measurements as well. This is independent of the particular working mode of the cell but influenced by the type of faulty behavior that is studied. The numerical results demonstrate the ill-posedness by the exponential decay behavior of the singular values for three examples of fault classes.