Extropy: Complementary Dual of Entropy

This article provides a completion to theories of information based on entropy, resolving a longstanding question in its axiomatization as proposed by Shannon and pursued by Jaynes. We show that Shannon's entropy function has a complementary dual function which we call "extropy." The entropy and the extropy of a binary distribution are identical. However, the measure bifurcates into a pair of distinct measures for any quantity that is not merely an event indicator. As with entropy, the maximum extropy distribution is also the uniform distribution, and both measures are invariant with respect to permutations of their mass functions. However, they behave quite differently in their assessments of the refinement of a distribution, the axiom which concerned Shannon and Jaynes. Their duality is specified via the relationship among the entropies and extropies of course and fine partitions. We also analyze the extropy function for densities, showing that relative extropy constitutes a dual to the Kullback-Leibler divergence, widely recognized as the continuous entropy measure. These results are unified within the general structure of Bregman divergences. In this context they identify half the $L_2$ metric as the extropic dual to the entropic directed distance. We describe a statistical application to the scoring of sequential forecast distributions which provoked the discovery.Comment: Published at http://dx.doi.org/10.1214/14-STS430 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Field Guide to Nonindigenous Marine Fishes of Florida

The purpose of this field guide is to provide information on nonindigenous (i.e., non-native) fishes that have been observed in Florida’s marine waters. Introductions of non-native marine fishes into Florida’s waters could be intentional or unintentional, and are likely from a variety of sources, including aquarium releases, escape from aquaculture, loss due to extreme weather events (e.g., flooding from hurricanes), and possibly transfer with ballast water or hull-fouling. Presently the lionfishes (Pterois volitans and P. miles) are the only non-native marine fish species known to be established along the coast of Florida. All other marine fishes in this guide (except the euryhaline species, see below) have infrequent occurrences, occur singly or in small groups, and have not yet become self-sustaining populations. Aquarium releases are one of the major pathways whereby nonindigenous fishes gain access to new environments (Ruiz et al. 1997; Fuller et al. 1999). Most of the nonindigenous marine fishes found in Florida’s waters are thought to be aquarium fishes that either were illegally released into the ocean or escaped captivity (e.g., during severe storm/flooding events). Indeed, south Florida is a hotspot for nonindigenous marine aquarium fishes (Semmens et al. 2004). Increased public awareness of the problems caused by released or escaped aquarium fishes may aid in stemming the frequency of releases. For example, HabitattitudeTM (www.habitattitude.net) is a national public awareness and partnership campaign that encourages aquarists and water gardeners to prevent the release of unwanted aquarium plants, fish and other animals. It prompts hobbyists to adopt alternative actions when dealing with these aquatic plants and animals. (PDF file contains 133 pages.

A computational method for simulating dispersed two-phase flows using the PDF approach

The thesis presents a Probability Density Function (PDF)-derived Eulerian/Eulerian model for the prediction of dispersed two-phase (solid/gas) flows. Continuum equations for the dispersed phase are formulated from the Kinetic Model (KM) PDF transport equations. The Kinetic stresses of the dispersed phase are determined from an algebraic stress model (ASM) together with a KM-based transport equation for the fluctuating kinetic energy. The continuum equations for the continuous phase are assumed to be the same as those in the Eulerian two-fluid model except for the interfacial momentum and energy transfer terms. Closures for these terms are derived from the PDF KM and mirror their counterparts in the dispersed phase equations. Also, the carrier phase turbulence is modelled by the standard k-ε model. These transport equations are solved using the numerical framework of an existing two-fluid approach. Furthermore, the current two-fluid model practice of applying wall functions to impose boundary conditions is adapted for application to the particulate phase. Such wall functions are calculated from the PDF KM itself. In this approach, the PDF equations are pre-integrated using the fully developed flow assumption along the wall to relate wall fluxes to values of the relevant variables in the interior of the flow. Such integration is utilised to create a wall functions database for a range of mean flow conditions. The model is validated against a range of both unbounded and bounded flow cases. Comparisons are made with experimental data as well as the results of other computational methods. It was found that the proposed model performs very well in capturing particulate behaviour and improves, in certain aspects, on the performance of traditional two-fluid models while retaining the practicality of the latter model for industrial applications. In particular, a reasonable capture of the particulate dispersion was observed within jet flows. Improvements were also seen in the prediction of mass flux distribution in shear layers and an accurate capture of near-wall mass distributions in bounded flows

Use of radiation in preparative chemistry

A summary and updating of previous work on the use of radiation chemistry for the preparation of pure materials are presented. Work was chiefly concerned with the reduction of metal salts in solution to the free metal using 2 MeV electrons. Metals deposited from aqueous solution are copper, silver, zinc, cadmium, thallium, tin, lead, antimony, iron, nickel, cobalt, and palladium. Dry organic solvents were evaluated for the deposition of metals based on a study involving deposition of antimony from soltions of antimony (III) chloride. The use of organic liquids for the preparation of anhydrous metal halides is also presented. Reaction mechanisms for both organic liquids and aqueous system are discussed

Further Studies on Inhibition of Growth of Spores of Penicillium Sp. and Aspergillus Sp. Isolated from the White Molds of Silages

Author Institution: Department of Chemistry and Department of Biology, Fenn College, Cleveland, OhioFinely powdered commercial sulfur does not inhibit appreciably the growth of spores of the white mold, Penicillium sp. and Aspergillus sp. Diethyl sulfite in concentration of 7.38 grams/liter is found to be toxic to the spores of the white mold, and its toxicity is markedly increased by addition of lactic acid. Infrared absorption spectra studies of mixtures of sodium metabisulfite and sodium lactate indicate no interaction between the sulfite and the lactate ions. The use of a solution of lactic acid and sodium bisulfite on heating silage in the silo gave considerable reduction in the temperature

Film in the city: a report on the film & video sub-Sector in London

The movie business, and the distribution of films through the associated cinema and home video sectors is a truly global phenomenon. In terms of both production and distribution, Hollywood has traditionally dominated international markets, however, with radical innovations in information and digital technologies and the spread of the Internet, it has become increasingly easier to make and distribute films around the world . Coupled with this is the ‘runaway production’ concept, whereby Hollywood productions are no longer tied to site-specific studios and can choose to shoot and edit their (usually high-budget) movies in locations around the globe. This has created an international market where cities, such as Vancouver, Sydney, Brisbane, Prague, Cape Town, London and many more, compete for big movie business. London has a thriving film and video sub-sector and a highly competitive infrastructure, nurtured by a host of supporting institutions, which together create a powerful creative network of players capable of competing at a global scale. The physical geography of the city also matters to the film industry, not only in terms of shooting locations, but also in determining where to locate, pitch or exhibit the final creative product. Consequently, the location and interconnected value chain of producers, post-production, financiers, sales agents and distributors, cinemas and theatres, as well as the myriad of specialised and highly skilled workforce is key to the industry’s success. The co-location and clustering tendencies of individuals and institutions located at close proximity in London and highlighted in this report are evidence of the intense social networking that characterises the industry

Thermal degradation of the tensile strength of unidirectional boron/aluminum composites

The variation of ultimate tensile strength with thermal treatment of B-Al composite materials and of boron fibers chemically removed from these composites in an attempt to determine the mechanism of the resulting strength degradation was studied. Findings indicate that thermally cycling B-Al represents a more severe condition than equivalent time at temperature. Degradation of composite tensile strength from about 1.3 GN/m squared to as low as 0.34 GN/m squared was observed after 3,000 cycles to 420 C for 203 micrometers B-1100 Al composite. In general, the 1100 Al matrix composites degraded somewhat more than the 6061 matrix material studied. Measurement of fiber strengths confirmed a composite strength loss due to the degradation of fiber strength. Microscopy indicated a highly flawed fiber surface

Collaborative Standards, Voluntary Codes and Industry Self-regulation

In a complex, global economy, firms seek a range of mechanisms for addressing regulatory and social movement pressures. This requires an evolution beyond our current models of response to regulation and control. This paper offers ideas on collaborative control and industry self-regulation as alternative mechanisms for addressing regulatory complexity. It explores a range of self-regulatory practices worldwide, proposes a framework for examining its use, potential and limits, and discusses the critical role of third-party organisations in the process