630 research outputs found
Dividing the Indivisible: Procedures for Allocating Cabinet Ministries to Political Parties in a Parliamentary System
Political parties in Northern Ireland recently used a divisor method of apportionment to choose, in sequence, ten cabinet ministries. If the parties have complete information about each others' preferences, we show that it may not be rational for them to act sincerely by choosing their most-preferred ministry that is available. One consequence of acting sophisticatedly is that the resulting allocation may not be Pareto-optimal, making all the parties worse off. Another is nonmonotonicty-choosing earlier may hurt rather than help a party. We introduce a mechanism that combines sequential choices with a structured form of trading that results in sincere choices for two parties. Although there are difficulties in extending this mechanism to more than two parties, other approaches are explored, such as permitting parties to making consecutive choices not prescribed by an apportionment method. But certain problems, such as eliminating envy, remain.APPORTIONMENT METHODS; CABINETS; SEQUENTIAL ALLOCATION; MECHANISM DESIGN; FAIRNESS
Dividing the indivisible : procedures for allocating cabinet ministries to political parties in a parliamentary system
parliament
Strange form factors in the context of SAMPLE, HAPPEX, and A4 experiments
The strange properties of the nucleon are investigated within the framework
of the SU(3) chiral quark-soliton model assuming isospin symmetry and applying
the symmetry conserving SU(3) quantization. We present the form factors
, and the electric and magnetic strange form
factors incorporating pion and kaon asymptotics. The results
show a fairly good agreement with the recent experimental data from the SAMPLE
and HAPPEX collaborations. We also present predictions for future measurements
including the A4 experiment at MAMI (Mainz).Comment: 10 pages with four figures. RevTeX4 is used. Few lines are changed.
Accepted for publication in Phys.Rev.
Ghost D-branes
We define a ghost D-brane in superstring theories as an object that cancels
the effects of an ordinary D-brane. The supergroups U(N|M) and OSp(N|M) arise
as gauge symmetries in the supersymmetric world-volume theory of D-branes and
ghost D-branes. A system with a pair of D-brane and ghost D-brane located at
the same location is physically equivalent to the closed string vacuum. When
they are separated, the system becomes a new brane configuration. We generalize
the type I/heterotic duality by including n ghost D9-branes on the type I side
and by considering the heterotic string whose gauge group is OSp(32+2n|2n).
Motivated by the type IIB S-duality applied to D9- and ghost D9-branes, we also
find type II-like closed superstrings with U(n|n) gauge symmetry.Comment: 49 pages, 6 figures, harvmac. v2: references and acknowledgements
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The prediction of preference for unfamiliar urban places
Preferences for unfamiliar urban environments were studied as a function of urban categories, viewing time, and four predictor variables: complexity, coherence, identifiability, and mystery. A nonmetric factor analysis of the preference ratings for the longest viewing-time condition yielded five dimensions: Contemporary Life, Alley/Factory, Urban Nature, Unusual Architecture, and Older Buildings. The five categories differed significantly in preference, with Urban Nature by far the most preferred and Alley/Factory distinctly disliked. The combination of low coherence and high complexity characterizes the least liked Alley/Factory category, while the role of mystery in the urban setting is highlighted by the most preferred Urban Nature category. The results point to various ways in which the urban environment could be more responsive to people's preferences.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43513/1/11111_2005_Article_BF01359051.pd
Conference Discussion of the Nuclear Force
Discussion of the nuclear force, lead by a round table consisting of T.
Cohen, E. Epelbaum, R. Machleidt, and F. Gross (chair). After an invited talk
by Machleidt, published elsewhere in these proceedings, brief remarks are made
by Epelbaum, Cohen, and Gross, followed by discussion from the floor moderated
by the chair. The chair asked the round table and the participants to focus on
the following issues: (i) What does each approach (chiral effective field
theory, large Nc, and relativistic phenomenology) contribute to our knowledge
of the nuclear force? Do we need them all? Is any one transcendent? (ii) How
important for applications (few body, nuclear structure, EMC effect, for
example) are precise fits to the NN data below 350 MeV? How precise do these
fits have to be? (iii) Can we learn anything about nonperturbative QCD from
these studies of the nuclear force? The discussion presented here is based on a
video recording made at the conference and transcribed afterward.Comment: Discussion at the 21st European Conference on Few Body Problems
(EFP21) held at Salamanca, Spain, 30 Aug - 3 Sept 201
Electroweak Radiative Corrections to Parity-Violating Electroexcitation of the
We analyze the degree to which parity-violating (PV) electroexcitation of the
resonance may be used to extract the weak neutral axial vector
transition form factors. We find that the axial vector electroweak radiative
corrections are large and theoretically uncertain, thereby modifying the
nominal interpretation of the PV asymmetry in terms of the weak neutral form
factors. We also show that, in contrast to the situation for elastic electron
scattering, the axial PV asymmetry does not vanish at the photon
point as a consequence of a new term entering the radiative corrections. We
argue that an experimental determination of these radiative corrections would
be of interest for hadron structure theory, possibly shedding light on the
violation of Hara's theorem in weak, radiative hyperon decays.Comment: RevTex, 76 page
A CsI(Tl) Scintillating Crystal Detector for the Studies of Low Energy Neutrino Interactions
Scintillating crystal detector may offer some potential advantages in the
low-energy, low-background experiments. A 500 kg CsI(Tl) detector to be placed
near the core of Nuclear Power Station II in Taiwan is being constructed for
the studies of electron-neutrino scatterings and other keV-MeV range neutrino
interactions. The motivations of this detector approach, the physics to be
addressed, the basic experimental design, and the characteristic performance of
prototype modules are described. The expected background channels and their
experimental handles are discussed.Comment: 34 pages, 11 figures, submitted to Nucl. Instrum. Method
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