673 research outputs found
When Do Campaigns Matter? Informed Votes, the Heteroscedastic Logit and the Responsiveness of Electoral Outcomes
Previous research suggests that voters in mass elections tend to be badly informed. If these voters do not know enough about the relationship between the policy consequences of electoral outcomes and their own interests, then electoral outcomes may not provide meaningful expressions of voter interests. Can campaign activity affect the relationship between voter interests and electoral outcomes? To answer this question, we use survey data from 35 comparable elections and a new empirical methodology (Dubin and Zeng's [1991] heteroscedastic logit). The new methodology allows us to estimate the joint effect of voter information and interests on voting behavior in a way that is both theoretically justifiable and better at explaining the available data than traditional methods. We find that campaign activity increases the likelihood that electoral outcomes are responsive to (perhaps, otherwise badly informed) voter interests, when campaigners are able to exert costly and observable effort, are able to make credible statements and have the opportunity to engage in a vigorous and competitive campaign
Properties of Factorial Cumulant to Factorial Moment Ratio
It is shown that the ratio of factorial cumulant moments to factorial moments
for a multiplicity distribution truncated in the tail reveals oscillations in
sign similar to those observed in experimental data. It is suggested that this
effect be taken into account in the analysis of data in order to obtain correct
physical information on the multiplicity distributions.Comment: (LaTeX + epsfig, 8 pages including 3 PostScript figures, all encoded
via uufiles), DFTT 46/9
Clan Structure in Rapidity Intervals
We present a cascading model for a single jet, inspired to QCD and to the
phenomenological analysis of multiplicity distributions. The model, describing
as it does a two dimensional evolution in virtuality and rapidity, allows
analytical predictions for clan analysis parameters to be made.Comment: Talk presented by R. Ugoccioni at XXV Multiparticle Dynamics, Stara
Lesna, Slovakia, Sept. 1995. LaTeX with epsfig, 11 pages, 3 figures.
Postscript file available through
http://www.thep.lu.se/tf2/hep/article.hep.htm
Maps of zeroes of the grand canonical partition function in a statistical model of high energy collisions
Theorems on zeroes of the truncated generating function in the complex plane
are reviewed. When examined in the framework of a statistical model of high
energy collisions based on the negative binomial (Pascal) multiplicity
distribution, these results lead to maps of zeroes of the grand canonical
partition function which allow to interpret in a novel way different classes of
events in pp collisions at LHC c.m. energies.Comment: 17 pages, figures (ps included); added references, some figures
enlarged. To appear in J. Phys.
Clan Properties in Parton Showers
By considering clans as genuine elementary subprocesses, i.e., intermediate
parton sources in the Simplified Parton Shower model, a generalized version of
this model is defined. It predicts analytically clan properties at parton level
in agreement with the general trends observed experimentally at hadronic level
and in Monte Carlo simulations both at partonic and hadronic level. In
particular the model shows a linear rising in rapidity of the average number of
clans at fixed energy of the initial parton and its subsequent bending for
rapidity intervals at the border of phase space, and approximate energy
independence of the average number of clans in fixed rapidity intervals. The
energy independence becomes stricter by properly normalizing the average number
of clans.Comment: (27 pages in Plain TeX plus 10 Postscript Figures, all compressed via
uufiles) DFTT 7/9
A combinatorial approach to angiosperm pollen morphology
Angiosperms (flowering plants) are strikingly diverse. This is clearly expressed in the morphology of their pollen grains, which are characterized by enormous variety in their shape and patterning. In this paper, I approach angiosperm pollen morphology from the perspective of enumerative combinatorics. This involves generating angiosperm pollen morphotypes by algorithmically combining character states and enumerating the results of these combinations. I use this approach to generate 3 643 200 pollen morphotypes, which I visualize using a parallel-coordinates plot. This represents a raw morphospace. To compare real-world and theoretical morphologies, I map the pollen of 1008 species of Neotropical angiosperms growing on Barro Colorado Island (BCI), Panama, onto this raw morphospace. This highlights that, in addition to their well-documented taxonomic diversity, Neotropical rainforests also represent an enormous reservoir of morphological diversity. Angiosperm pollen morphospace at BCI has been filled mostly by pollen morphotypes that are unique to single plant species. Repetition of pollen morphotypes among higher taxa at BCI reflects both constraint and convergence. This combinatorial approach to morphology addresses the complexity that results from large numbers of discrete character combinations and could be employed in any situation where organismal form can be captured by discrete morphological characters
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