Preface to Second Edition

Abstract

Since the publication of the second edition of this book, in 2006, several important changes have occurred in the domain of computer arithmetic. First, a new version of the IEEE-754 Standard for Floating-Point Arithmetic was adopted in June 2008. This new version was merged with the previous binary (754) and "radix independent" (854) standards, resolved some ambiguities of the previous release, standardized the fused multiplyadd (FMA) instruction, and included new formats (among them, the bina-ry128 format, previously called "quad precision"). An appendix to this new IEEE 754-2008 standard also makes some important recommendations concerning the elementary functions. New tools have been released that make much easier the work of a programmer eager to implement very accurate functions. A typical example is Sollya. 1 Sollya offers, among many interesting features, a certified supremum norm of the difference between a polynomial and a function. It also computes very good polynomial approximations with constraints (such as requiring the coefficients to be exactly representable in a given format). Another example is Gappa, 2 which simplifies the calculation of error bounds for small "straight-line" numerical programs (such as those designed for evaluating elementary functions), and makes it possible to use proof checkers such as Coq for certifying these bounds. FloPoCo 3 is a wonderful tool for implementing floating-point functions on FPGAs. Research in this area is still very active. To cite a few examples: Harrison designed clever techniques for implementing decimal transcendental functions using the binary functions; Chevillard, Harrison, Joldes, and Lauter introduced a new algorithm for computing certified supremum norms of approximation errors; Johansson designed new algorithms for implementing functions in the "medium precision" range; Brunie et al. designed code generators for mathematical functions; several authors (especially de Dinechin) introduced hardware-oriented techniques targeted at FPGA implementation; Brisebarre and colleagues introduced methods for rigorous polynomial approximation. 1

Materials and Device Design for Epidermal UV Sensors with Real‐Time, Skin‐Color Specific, and Naked‐Eye Quasi‐Quantitative Monitoring Capabilities

“…SINO and TPSO belong to the spirobenzoyran derivatives and spirobenzoyrans are a widely studied chemical class of compounds that exhibit photochromism. [ 27 ] They consist structurally of a pyran ring, usually a 2H‐1benzopyran, linked via a common spiro group to another heterocyclic ring. With higher energy irradiation of UV light (UV range of the 200 to 400 nm) the colorless spirobenzopyran causes heterolytic cleavage of the carbon–oxygen bond, forming the colored merocyanine ring‐opened isomers (blue color for SINO and magenta color for TPSO in this work).…”

A series of viologen complexes containing thiophene and Br− dual fluorescent chromophores for continuous visual sensing of pH and Hg2+

“…[24][25][26][27] The process occurs without bond breakage/formation, resulting in minimal disturbance to the molecular and crystal structure, which facilitates the reversibility of the discoloration process. [28][29][30][31] In this case, more and more attention has been devoted to the development of coordination polymer (CP) or metal organic frameworks (MOF) using viologen-derived ligands. Therefore, the introduction of viologen is expected to achieve colour modulation and they can be better combined with chemical sensors to achieve colour analysis.…”

Chromic textiles: Colour fastness properties and irreversible colour change behaviour of textiles screen printed with thermochromic, photochromic and hydrochromic colourants

“…Interactive coloured textiles can be developed by means of chromic materials, a class of smart materials that exhibit chromatic variation in response to a stimulus that each colourant type reacts to. This dynamic and interactive behaviour is reversible and it is based on the variation of the substances' microstructure or electronic state 1 …”