An analytic solution to the Busemann-Petty problem on sections of convex bodies

We derive a formula connecting the derivatives of parallel section functions of an origin-symmetric star body in R^n with the Fourier transform of powers of the radial function of the body. A parallel section function (or (n-1)-dimensional X-ray) gives the ((n-1)-dimensional) volumes of all hyperplane sections of the body orthogonal to a given direction. This formula provides a new characterization of intersection bodies in R^n and leads to a unified analytic solution to the Busemann-Petty problem: Suppose that K and L are two origin-symmetric convex bodies in R^n such that the ((n-1)-dimensional) volume of each central hyperplane section of K is smaller than the volume of the corresponding section of L; is the (n-dimensional) volume of K smaller than the volume of L? In conjunction with earlier established connections between the Busemann-Petty problem, intersection bodies, and positive definite distributions, our formula shows that the answer to the problem depends on the behavior of the (n-2)-nd derivative of the parallel section functions. The affirmative answer to the Busemann-Petty problem for n\le 4 and the negative answer for n\ge 5 now follow from the fact that convexity controls the second derivatives, but does not control the derivatives of higher orders.Comment: 13 pages, published versio

Global Commodity Markets - Price Volatility and Financialisation

A significant increase in the level and volatility of many commodity prices over the past decade has led to a debate about what has driven these developments. A particular focus has been on the extent to which they have been driven by increased financial investment in commodity derivatives markets. This article examines the factors behind the increase in the level and volatility of commodity prices. The available evidence suggests that while financial investors can affect the short-run price dynamics for some commodities, the level and volatility of commodity prices appear to be primarily determined by fundamental factors.Commodity; Commodities; Commodity prices; Commodity price; volatility; Speculation; Oil prices; Financialisation; Financialization; G-20; G20; CRB; Derivatives

An Experimental and Analytical Approach to Understanding the Dynamic Leaching from Municipal Solid Waste Combustion Residue

This paper describes an experimental technique involving the use of small columns for generating significant quantities of leachate data from municipal solid waste (MSW) solid residues within a relatively short amount of time. Data analysis using the discretized mass balance equations descriptive of the system results in best estimates of governing transport parameters that can, in turn, be used to predict the long-term release of leachable components (As, Cd, Cu, Fe, Ni, Pb, Zn, Ca, Mg, Na, K, Cl, SO4) from the solid matrix. Results indicate that both chemical solubility and physical transport are important factors affecting the flux of contaminants from the solid to the solution phase

Entre escuchar y sonar: explorando los límites de los instrumentos aumentados

This paper explores some of the changed relationships between body and environment that occur when instruments are augmented by electronic or digital circuits. Taking Gregory Bateson’s theorisation of the schizophrenic body (1973) as its starting point, the paper explores situations in which the relationship between the performer, body, and instrument takes on increasingly separate communicational modes, in which the body and its meanings come to resemble the ‘unlabelled metaphor’ of the schizophrenic. A series of instrument/personas are brought before us, representing both the ‘norm’ of acoustic instrumental performances and the extreme limits of instrumental identity, offering critical insight into the space that augmented instruments occupy and transform.  In considering some of these changes, and in reaching towards their extremities, attention is paid to the friction or awkwardness that accompanies the metamorphosis. In the same way that the ability of a language to ‘point’ is fraught with inconsistencies and potentials for misunderstanding, so the transformation in instrumental identities does not happen in a smooth and transparent way. However, the changes do create the potential for new sensibilities and forms of critical and ethical awareness.Este artículo explora algunos de los cambios en las relaciones entre cuerpo y ambiente que ocurren cuando los instrumentos son aumentados por circuitos electrónicos o digitales. Tomando como punto de partida las teorías de Gregory Bateson sobre el cuerpo esquizofrénico (1973), este texto pone en escena una serie de situaciones donde la relación entre ejecutor, cuerpo e instrumento toma formas de comunicación cada vez más separadas en las cuales el cuerpo y sus significados pueden parecer una ‘metáfora no etiquetada’ de esquizofrenia. Para recorrer este proceso, una serie de instrumentos/personas se nos presentan como representantes de la ‘norma’ en la ejecución de los instrumentos acústicos y los límites extremos de identidad instrumental, y ofrecen una perspectiva crítica en el espacio que los instrumentos aumentados ocupan y transforman. Explorando algunos de estos cambios y alcanzando sus extremos, se hace hincapié en la fricción o incomodidad que acompaña esta metamorfosis. Así como el lenguaje tiene la habilidad de ‘indicar’ y el posicionamiento de una ‘auto-icona’ en su interior se revela un proceso complejo cargado de inconsistencias y potenciales malentendidos, la transformación de las identidades instrumentales no ocurre de una manera transparente y fluida, sino que deja vestigios importantes de estados previos latentes en los nuevos

Module Reflections from ACUE Course in Effective Teaching Practices

Five Module Reflections from ACUE Course in Effective Teaching Practices (1E) Planning an Effective Class Session: use an engagement trigger (3C) Delivering an Effective Lecture: end with an effective closing (3D) Planning Effective Class Discussions: sequence questions to progress toward higher-order thinking (3E) Facilitating Engaging Class Discussions: manage the dominant talker (4B) Using Concept Maps and Other Visual Tools: integrate visual tools in a class sessio

Advanced Computer Program Models : A Talking Textbook Based on Three Languages

The purpose of this dissertation was to develop a learning instrument, to be used by programmers preparing for the Data Processing Management Association Test as a self study book, or by college business programming and computer science students who have completed a course in data processing and a course in programming a higher level language. The mathematical ability requirement was minimized by developing the algorithms in parallel with the programs. The learner should experience _emphasis in the following .areas: l. The type of activities required to pass the DPMA test (the programming part) 2. Data Structures 3. Fortran (at the level of the DPMA test) I 4. RPG (at the level of the DPMA test) 5. Flow chart reading and writing Fortran and RPG (Report Program Generator) languages were used, since their proficiency is required for the DPMA test; however a subset of IBM Basic Assembler language was used, because the author believed that a person who is more than superficially interested in computers should demonstrate a proficiency with a machine language. An important part of this method of presentation are the cassette recordings which allow the learner to progress outside the classroom. The recordings plus the hard copy of the actual programs, diminished in size, give the learner material which he can move to any location and study without the presence of the instructor

Chloride transport through concrete and implications for rapid chloride testing

Word processed copy. Includes bibliographical references (leaves 171-182)

A Pacifist’s Point: William Warder Cadbury, His Mission in Canton, and Public Health Initiatives 1909–1937

This paper examines the mission of William Warder Cadbury (1877–1959) to Canton from 1909 to 1937. As a Quaker medical missionary, Cadbury had the freedom to move around Canton and engage himself in the projects that interested him. He used this to engage in a number of public health projects. He had more power to do this inside of Lingnan University than out of it, mapping the limits of private individuals to bring about public health and the way in which Cadbury himself inserted into a debate about the future of Chinese modernity

The effect of electronically mediated sound on group musical interaction: A case study of the practice and development of the Automatic Writing Circle

The interaction between musicians has been one of the traditional strengths of music: it stretches to include an audience and ritual participants but has its origins in group activity, the interpersonal responses of one musician to another. This thesis examines the way that electronic media have transformed the interactions between musicians, particularly in the context of live performance. A central theme is the way in which mediatisation creates new splits within previously integrated musical situations and also merges differences usually defined by physical boundaries. The theories of Gregory Bateson on schizophrenia and Irving Goffman on Situationism are brought together to create a new understanding of the term "schizophonia". This rehabilitated concept is proposed as the key to a creative exploration of new situations and discontinuities which make up group performance in a mediatised environment. In practical terms the exploration of new musical situations is documented in the following projects: the material created for the group "Automatic Writing Circle" during its evolution over a period of six years (compositions, software, instruments), development of the Ouija Board and accompanying software, composition of the piece Lipsync and the earlier piece I slept by numbers for flute and live electronics