Letter to Bichler and Nitzan: points of agreement and disagreement on the labour theory of value and on power

Commentary on and critique of Bichler and Nitzan’s power theory of value and capital accumulation

LS Penrose’s limit theorem: Tests by simulation

LS Penrose’s limit theorem (PLT) – which is implicit in Penrose [5, p. 72] and for which he gave no rigorous proof – says that, in simple weighted voting games, if the number of voters increases indefinitely while existing voters retain their weights and the relative quota is pegged, then – under certain conditions – the ratio between the voting powers of any two voters converges to the ratio between their weights. Lindner and Machover [3] prove some special cases of PLT; and conjecture that the theorem holds, under rather general conditions, for large classes of weighted voting games, various values of the quota, and with respect to several measures of voting power. We use simulation to test this conjecture. It is corroborated w.r.t. the Penrose–Banzhaf index for a quota of 50% but not for other values; w.r.t. the Shapley–Shubik index the conjecture is corroborated for all values of the quota (short of 100%).limit theorems, majority games, simulation, weighted voting games

Experimental investigation on spark ignition of annular premixed combustors

The ignition behaviour of a multiple-burner annular combustion chamber consisting of 12 or 18 bluff-body premixed methane-air swirl burners was investigated experimentally. The study focusses on the mechanism of lightround, namely the burner-to-burner flame propagation. Side visualization of the spreading flame by 5 kHz OH* chemiluminescence showed that propagation from burner to burner did not follow a purely azimuthal direction, but a sawtooth pattern with downstream and sideways motion from one burner to the following, bringing flame to the downstream part of the recirculation zone of the adjacent burner before being convected upstream leading to full burner ignition. This pattern was more pronounced when the burners where fitted with swirlers. Top visualization and image processing were used to quantify the speed of lightround as a function of inter-burner spacing, bulk velocity, equivalence ratio, and swirling feature. It was found that flame spread from burner to burner following two balanced modes of propagation. These are turbulent flame propagation combined with volumetric expansion in the inter-burner region and convection within the next un-ignited burner. The results presented in this paper bring new insights into the ignition of realistic gas turbines.The authors acknowledge financial assistance from EPSRC and Rolls–Royce Group

The Category of Node-and-Choice Forms, with Subcategories for Choice-Sequence Forms and Choice-Set Forms

The literature specifies extensive-form games in many styles, and eventually I hope to formally translate games across those styles. Toward that end, this paper defines $\mathbf{NCF}$, the category of node-and-choice forms. The category's objects are extensive forms in essentially any style, and the category's isomorphisms are made to accord with the literature's small handful of ad hoc style equivalences. Further, this paper develops two full subcategories: $\mathbf{CsqF}$ for forms whose nodes are choice-sequences, and $\mathbf{CsetF}$ for forms whose nodes are choice-sets. I show that $\mathbf{NCF}$ is "isomorphically enclosed" in $\mathbf{CsqF}$ in the sense that each $\mathbf{NCF}$ form is isomorphic to a $\mathbf{CsqF}$ form. Similarly, I show that $\mathbf{CsqF_{\tilde a}}$ is isomorphically enclosed in $\mathbf{CsetF}$ in the sense that each $\mathbf{CsqF}$ form with no-absentmindedness is isomorphic to a $\mathbf{CsetF}$ form. The converses are found to be almost immediate, and the resulting equivalences unify and simplify two ad hoc style equivalences in Kline and Luckraz 2016 and Streufert 2019. Aside from the larger agenda, this paper already makes three practical contributions. Style equivalences are made easier to derive by [1] a natural concept of isomorphic invariance and [2] the composability of isomorphic enclosures. In addition, [3] some new consequences of equivalence are systematically deduced.Comment: 43 pages, 9 figure

Playing fast and loose with music recognition

We report lessons from iteratively developing a music recognition system to enable a wide range of musicians to embed musical codes into their typical performance practice. The musician composes fragments of music that can be played back with varying levels of embellishment, disguise and looseness to trigger digital interactions. We collaborated with twenty-three musicians, spanning professionals to amateurs and working with a variety of instruments. We chart the rapid evolution of the system to meet their needs as they strove to integrate music recognition technology into their performance practice, introducing multiple features to enable them to trade-off reliability with musical expression. Collectively, these support the idea of deliberately introducing ‘looseness’ into interactive systems by addressing the three key challenges of control, feedback and attunement, and highlight the potential role for written notations in other recognition-based systems

PROSECUTING ALLEGED ISRAELI WAR CRIMINALS IN ENGLAND AND WALES

The criminal justice system in England & Wales is faced with allegations made by Palestinians of Israeli war crimes contrary to the Geneva Conventions Act 1957 (and which in some cases also involve allegations of torture contrary to s134 Criminal Justice Act 1988) – how will it cope with this challenge