Providing Public Goods Without Strong Sanctioning Institutions

This paper proposes a simple mechanism aimed to establish positive contributions to public goods in the absence of powerful institutions to sanction free-riders. The idea of the mechanism is to require players to commit to the public good by paying a deposit prior to the contribution stage. If all players commit in this way, those players who do not contribute their share to the public good forfeit their deposit. If there is no universal commitment, all deposits are refunded and the standard game is played. Given deposits are sufficiently high, prior commitment and full ex post contributions are part of a strict subgame perfect Nash equilibrium for the resulting game. As the mechanism obviates the need for any ex post prosecution of free-riders, it is particularly suited for situations where players do not submit to a common authority as in the case of international agreements

Providing Public Goods Without Strong Sanctioning Institutions

This paper proposes a simple mechanism aimed to establish positive contributions to public goods in the absence of powerful institutions to sanction free-riders. The idea of the mechanism is to require players to commit to the public good by paying a deposit prior to the contribution stage. If all players commit in this way, those players who do not contribute their share to the public good forfeit their deposit. If there is no universal commitment, all deposits are refunded and the standard game is played. Given deposits are sufficiently high, prior commitment and full ex post contributions are part of a strict subgame perfect Nash equilibrium for the resulting game. As the mechanism obviates the need for any ex post prosecution of free-riders, it is particularly suited for situations where players do not submit to a common authority as in the case of international agreements.public goods; cooperation; institutions; Climate-Change Treaties

Mixing and merging for spoken document retrieval

This paper describes a number of experiments that explo- red the issues surrounding the retrieval of spoken documents. Two such issues were examined. First, attempting to find the best use of speech recogniser output to produce the highest retrieval effectiveness. Second, investigating the potential problems of retrieving from a so-called "mi- xed collection", i.e. one that contains documents from both a speech recognition system (producing many errors) and from hand transcription (producing presumably near perfect documents). The result of the first part of the work found that merging the transcripts of multiple recognisers showed most promise. The investigation in the second part showed how the term weighting scheme used in a retrieval system was important in determining whether the system was affected detrimentally when retrieving from a mixed collection

Asymmetric field dependence of magnetoresistance in magnetic films

We study an asymmetric in field magnetoresistance that is frequently observed in magnetic films and, in particular, the odd longitudinal voltage peaks that appear during magnetization reversal in ferromagnetic films, with out-of-plane magnetic anisotropy. We argue that the anomalous signals result from small variation of magnetization and Hall resistivity along the sample. Experimental data can be well described by a simple circuit model, the latter being supported by analytic and numerical calculations of current and electric field distribution in films with a gradual variation of the magnetization and Hall resistance.Comment: 7 pages, 5 figures, to be published in Phys. Rev.

Modernist Pedagogies: Conrad, Woolf, Pound, and the Reading Public

"Modernist Pedagogies: Conrad, Woolf, Pound, and the Reading Public" challenges the widely held belief that modernist writers were uninterested in reaching the emerging reading public that developed as a result of the 1870 Education Act and subsequent reforms in Britain. I contend that Conrad, Woolf, and Pound were largely optimistic that, with a particular type of guidance, the reading public was capable of engaging with difficult texts. Conrad's prefaces, Woolf's lectures and BBC broadcasts, and Ezra Pound's How To Read and ABC of Reading offer varied pedagogical motivations and methods with implications for not only how we teach these major authors but also how we teach reading and writing at the university level. By challenging prevailing understandings of the modernists' attitudes toward the reading public, this study offers a more complex rendering of the modernists' relationships with the expanded reading public, thereby enabling a fuller understanding of the modernist project

Splitting between Bright and Dark excitons in Transition Metal Dichalcogenide Monolayers

The optical properties of transition metal dichalcogenide monolayers such as the two-dimensional semiconductors MoS$_2$ and WSe$_2$ are dominated by excitons, Coulomb bound electron-hole pairs. The light emission yield depends on whether the electron-hole transitions are optically allowed (bright) or forbidden (dark). By solving the Bethe Salpeter Equation on top of $GW$ wave functions in density functional theory calculations, we determine the sign and amplitude of the splitting between bright and dark exciton states. We evaluate the influence of the spin-orbit coupling on the optical spectra and clearly demonstrate the strong impact of the intra-valley Coulomb exchange term on the dark-bright exciton fine structure splitting.Comment: 6 pages, 2 figure

Studies of single top production at the Tevatron

I present the newest measurements of the production cross sections of single top quarks in pp collisions at √s = 1.96TeV in a data sample corresponding to an integrated luminosity of 5.4 fb−1 collected by the D0 detector at the Fermilab Tevatron Collider. The data is also used to extract limits on the CKM Matrix element |Vtb|