Accomplishing Accomplishment

The concepts of knowledge and accomplishment are duals. There are many parallels between them. In this paper I discuss the "AA" thesis, which is dual to the well known KK thesis. The KK thesis claims that if someone knows something, then she knows that she knows it. This is generally thought to be false, and there are powerful reasons for rejecting it. The AA thesis claims that if someone accomplishes something, then she accomplishes that she accomplishes it. I argue that this, too, is false, and that the reasons it is false parallel reasons for the falsity of the KK thesis.     

Capturing preferences for inequality aversion in decision support

We investigate the situation where there is interest in ranking distributions (of income, of wealth, of health, of service levels) across a population, in which individuals are considered preferentially indistinguishable and where there is some limited information about social preferences. We use a natural dominance relation, generalised Lorenz dominance, used in welfare comparisons in economic theory. In some settings there may be additional information about preferences (for example, if there is policy statement that one distribution is preferred to another) and any dominance relation should respect such preferences. However, characterising this sort of conditional dominance relation (specifically, dominance with respect to the set of all symmetric increasing quasiconcave functions in line with given preference information) turns out to be computationally challenging. This challenge comes about because, through the assumption of symmetry, any one preference statement (“I prefer giving $100 to Jane and $110 to John over giving $150 to Jane and $90 to John”) implies a large number of other preference statements (“I prefer giving $110 to Jane and $100 to John over giving $150 to Jane and $90 to John”; “I prefer giving $100 to Jane and $110 to John over giving $90 to Jane and $150 to John”). We present theoretical results that help deal with these challenges and present tractable linear programming formulations for testing whether dominance holds between any given pair of distributions. We also propose an interactive decision support procedure for ranking a given set of distributions and demonstrate its performance through computational testing.     

On the control of quantum statistical systems

The problem of preparing a system in some initial configuration is discussed for quantum statistical systems whose dynamics are generated by Markovian semigroups. The system is regulated by a set of controls and the central problem is to determine how the controls should be varied in order to bring the system as close as possible to the desired configuration in a fixed finite time. General equations are derived which allow one to determine how the controls should be regulated. The application of the result to a simple system is outlined.     

On continuum thermodynamics with mutual body forces and internal radiation

Zusammenfassung In diesem Artikel betrachten wir Stoffe, in denen innere Volumenkräfte und innere Wärmestrahlung vorkommen können. Wir zeigen auf welche Weise der zweite Hauptsatz der Thermodynamik die Form der Stoffgleichungen einschränkt. Zum Beispiel ergibt es sich, dass die Volumenkraft ein Potential hat und dass dieses Potential zur inneren Energie beiträgt.     

On the thermodynamics of non-simple elastic materials with two temperatures

Zusammenfassung Diese Arbeit behandelt eine thermodynamische Theorie von nichteinfachen, elastischen Stoffen. Es wird gezeigt, dass Substanzen vom Grade höher als eins vorkommen können; vorausgesetzt, dass man das eventuelle Vorhandensein zweier verschiedener Temperaturen in Betracht zieht.     

A melt depth prediction model for quality control of laser surface glazing of inhomogeneous materials

This paper reports on an investigation into the development of an analytical model for the quality control of laser marking/engraving of clay tiles using a high-power diode laser (HPDL). An analytical model for the laser melting of inhomogeneous workpieces with parabolic melt pool geometry being assumed was developed. The theoretical results were compared with the experimental data. The predicted melt pool depth and the experimental values were in close correlation with the parameter for values less than 15 Wmm⁻¹ s^−1/2, in spite of simplifications introduced in the model. At the relatively large values of parameter the assumption of parabolic melt pool shape and one-dimensional heat transfer no longer holds true.     

Fission and emission of H and He in the reactions of 215 MeV16O with181Ta,208Pb and238U

The reactions of 215 MeV¹⁶O with¹²C,¹⁸¹Ta,²⁰⁸Pb and²³⁸U have been studied. Inclusive measurements for⁴He emission are given from each target, and for fission and^1,2,3H from Ta, Pb and U. For H/He a high-energy, forward-peaked component is observed with characteristics similar to those reported by others. At backward angles a low-energy, nearly-isotropic component is also observed for⁴He that cannot be accounted for by emission from fully accelerated fission products. The spectral shapes for this evaporative component are compared with statistical model calculations, and information is obtained concerning the effective barriers to emission. For the reactions of¹⁶O with¹²C, complete fusion seems to be overwhelmed by incomplete fusion. Fission angular distributions and cross sections are also presented and discussed.