2,296 research outputs found
On the identity and systematic placement of Onthophagus viriditinctus Reitter, 1892 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini)
A re-description and new records of Onthophagus viriditinctus Reitter, 1892 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini), an uncommon species from Iran, are provided. The taxonomic position and some nomenclatural problems are discussed. The placement in the subgenus Exonthophagus Kabakov, 2006 is proposed. Images of the male, female, aedeagus and drawings of lamella copulatrix of Onthophagus viriditinctus and Onthophagus haroldi Ballion, 1871, the only other species included in the subgenus, are supplied. A key for distinguishing the two species is provided
An efficient segmentation method to price American Put options
A segmentation strategy to price different groups of American standard Put options with different methods is presented and discussed. The method, which exploits the properties of the odd waves of the BI adjusted evaluations introduced by Gaudenzi and Pressacco, proves to be very efficient in particular, to price critical in the money options.American put plain vanilla options; tree evaluation methods; American quality; segmentation
Bilateral symmetry and modified Pascal triangles in Parsimonious games
We discuss the prominent role played by bilateral symmetry and modified
Pascal triangles in self twin games, a subset of constant sum homogeneous
weighted majority games. We show that bilateral symmetry of the free
representations unequivocally identifies and characterizes this class of games
and that modified Pascal triangles describe their cardinality for combinations
of m and k, respectively linked through linear transforms to the key parameters
n, number of players and h, number of types in the game. Besides, we derive the
whole set of self twin games in the form of a genealogical tree obtained
through a simple constructive procedure in which each game of a generation,
corresponding to a given value of m, is able to give birth to one child or two
children (depending on the parity of m), self twin games of the next
generation. The breeding rules are, given the parity of m, invariant through
generations and quite simple.Comment: pp. 2
Taxonomic notes on Onthophagus (Palaeonthophagus) lemuroides d’Orbigny, 1898 and O. (P.) fortigibber Reitter, 1909 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini)
The taxonomic position of Onthophagus (Palaeonthophagus) lemuroides d’Orbigny, 1898 and Onthophagus
(Palaeonthophagus) fortigibber Reitter, 1909 is discussed (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini).
A key to the species is given. Photos of type specimens of the two taxa and significant chromatic varieties, and
drawings of aedeagi are presented
Twin relationships in Parsimonious Games: some results
In a vintage paper concerning Parsimonious games, a subset of constant sum
homogeneous weighted majority games, Isbell introduced a twin relationship
based on transposition properties of the incidence matrices upon minimal
winning coalitions of such games. A careful investigation of such properties
allowed the discovery of some results on twin games presented in this paper. In
detail we show that a) twin games have the same minimal winning quota and b)
each Parsimonious game admits a unique balanced lottery on minimal winning
coalitions, whose probabilities are given by the individual weights of its twin
game
Access to Population-Level Signaling as a Source of Inequality
We identify and explore differential access to population-level signaling
(also known as information design) as a source of unequal access to
opportunity. A population-level signaler has potentially noisy observations of
a binary type for each member of a population and, based on this, produces a
signal about each member. A decision-maker infers types from signals and
accepts those individuals whose type is high in expectation. We assume the
signaler of the disadvantaged population reveals her observations to the
decision-maker, whereas the signaler of the advantaged population forms signals
strategically. We study the expected utility of the populations as measured by
the fraction of accepted members, as well as the false positive rates (FPR) and
false negative rates (FNR).
We first show the intuitive results that for a fixed environment, the
advantaged population has higher expected utility, higher FPR, and lower FNR,
than the disadvantaged one (despite having identical population quality), and
that more accurate observations improve the expected utility of the advantaged
population while harming that of the disadvantaged one. We next explore the
introduction of a publicly-observable signal, such as a test score, as a
potential intervention. Our main finding is that this natural intervention,
intended to reduce the inequality between the populations' utilities, may
actually exacerbate it in settings where observations and test scores are
noisy
K-Fibonacci sequences and minimal winning quota in Parsimonious game
Parsimonious games are a subset of constant sum homogeneous weighted majority
games unequivocally described by their free type representation vector. We show
that the minimal winning quota of parsimonious games satisfies a second order,
linear, homogeneous, finite difference equation with nonconstant coefficients
except for uniform games. We provide the solution of such an equation which may
be thought as the generalized version of the polynomial expansion of a proper
k-Fibonacci sequence. In addition we show that the minimal winning quota is a
symmetric function of the representation vector; exploiting this property it is
straightforward to prove that twin Parsimonious games, i.e. a couple of games
whose free type representations are each other symmetric, share the same
minimal winning quota
AFM probe for the signatures of Wigner correlations in the conductance of a one-dimensional quantum dot
The transport properties of an interacting one-dimensional quantum dot
capacitively coupled to an atomic force microscope probe are investigated. The
dot is described within a Luttinger liquid framework which captures both
Friedel and Wigner oscillations. In the linear regime, we demonstrate that both
the conductance peak position and height oscillate as the tip is scanned along
the dot. A pronounced beating pattern in the conductance maximum is observed,
connected to the oscillations of the electron density. Signatures of the
effects induced by a Wigner molecule are clearly identified and their stability
against the strength of Coulomb interactions are analyzed. While the
oscillations of the peak position due to Wigner get enhanced at strong
interactions, the peak height modulations are suppressed as interactions grow.
Oscillations due to Friedel, on the other hand, are robust against interaction.Comment: 9 figure
Probing Wigner correlations in a suspended carbon nanotube
The influence of the electron-vibron coupling on the transport properties of
a strongly interacting quantum dot built in a suspended carbon nanotube is
analyzed. The latter is probed by a charged AFM tip scanned along the axis of
the CNT which induces oscillations of the chemical potential and of the linear
conductance. These oscillations are due to the competition between finite-size
effects and the formation of a Wigner molecule for strong interactions. Such
oscillations are shown to be suppressed by the electron-vibron coupling. The
suppression is more pronounced in the regime of weak Coulomb interactions,
which ensures that probing Wigner correlations in such a system is in principle
possible
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