650 research outputs found
Implementation of Democratic Social Choice Functions
A social choice function is said to be implementable if and only if there exists a game form such that for all preference profiles an equilibrium strategy n-tuple exists and any equilibrium strategy n-tuples of the game yield outcomes in the social choice set. A social choice function is defined to be minimally democratic if and only if whenever there exists an alternative which is ranked first by n-1 voters and is no lower than second for the last voter, then the social choice must be uniquely that alternative. No constraints are placed on the social choice function for other preference profiles.
Using the usual definitions of equilibria for n-person gamesânamely Nash and strong equilibriaâit is shown here that over unrestricted preference domains, no minimally democratic social choice function is implementable. The same result holds in certain restricted domains of the type assumed by economists over public goods spaces. We then show that a different notion of equilibriumânamely that of sophisticated equilibriumâallows for implementation of democratic social choice functions also having further appealing properties. The implication is that models of democratic political processes cannot be based on the standard equilibrium notions of Nash or strong equilibria
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Measurement of Circumsolar Radiation. Status Report
The major accomplishments of this project include the design, construction, and deployment of four complete circumsolar telescope systems. The telescopes have been maintained and data have been collected from a total of nine sites over the past two years. The data upon reaching LBL have been compiled, validated and analyzed for dissemination to DOE and other users. LBL has been collaborating with other national laboratories to quantify the impact of circumsolar radiation on specific solar collector designs. Requests for data from a wide variety of solar users have been fulfilled
Occupational Health and Safety Prevention Plan in Water Treatment Plant
The research was carried out at the "El Guarumo" drinking water plant located in Santa Ana, province of ManabĂ, Ecuador. The objective of the investigation was the proposal of a plan of prevention of occupational risks that allows the management of the labor risks in said plant. The main tools used were: survey, interview, checklist, LEST questionnaire for the diagnosis of the current situation in terms of working conditions, the risk identification matrix and the binary method of risk assessment. The main results obtained were the identification of the risks in their different categories, observing that the critical risk factors are related to the physical overexertion, the uncomfortable postures and the manual lifting of the load. Among the important risks are falling objects, skin contact with toxic substances and mental overwork, closely related to work pressures and job security? It was possible to carry out the proposal of preventive and corrective measures in order to properly manage the risks and contribute to the safety and health of the workers
Detection Of KOI-13.01 Using The Photometric Orbit
We use the KOI-13 transiting star-planet system as a test case for the
recently developed BEER algorithm (Faigler & Mazeh 2011), aimed at identifying
non-transiting low-mass companions by detecting the photometric variability
induced by the companion along its orbit. Such photometric variability is
generated by three mechanisms, including the beaming effect, tidal ellipsoidal
distortion, and reflection/heating. We use data from three Kepler quarters,
from the first year of the mission, while ignoring measurements within the
transit and occultation, and show that the planet's ephemeris is clearly
detected. We fit for the amplitude of each of the three effects and use the
beaming effect amplitude to estimate the planet's minimum mass, which results
in M_p sin i = 9.2 +/- 1.1 M_J (assuming the host star parameters derived by
Szabo et al. 2011). Our results show that non-transiting star-planet systems
similar to KOI-13.01 can be detected in Kepler data, including a measurement of
the orbital ephemeris and the planet's minimum mass. Moreover, we derive a
realistic estimate of the amplitudes uncertainties, and use it to show that
data obtained during the entire lifetime of the Kepler mission, of 3.5 years,
will allow detecting non-transiting close-in low-mass companions orbiting
bright stars, down to the few Jupiter mass level. Data from the Kepler Extended
Mission, if funded by NASA, will further improve the detection capabilities.Comment: Accepted to AJ on October 4, 2011. Kepler Q5 Long Cadence data will
become publicly available on MAST by October 23. Comments welcome (V2: minor
changes, to reflect proof corrections
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I owe you: age-related similarities and differences in associative memory for gains and losses
Older adults often experience associative memory impairments but can sometimes remember important information. The current experiments investigate potential age-related similarities and differences associate memory for gains and losses. Younger and older participants were presented with faces and associated dollar amounts, which indicated how much money the person âowedâ the participant, and were later given a cued recall test for the dollar amount. Experiment 1 examined face-dollar amount pairs while Experiment 2 included negative dollar amounts to examine both gains and losses. While younger adults recalled more information relative to older adults, both groups were more accurate in recalling the correct value associated with high value faces compared to lower value faces and remembered gist-information about the values. However, negative values (losses) did not have a strong impact on recall among older adults versus younger adults, illustrating important associative memory differences between younger and older adults
PHL 5038: a spatially resolved white dwarf + brown dwarf binary
A near-infrared excess is detected at the white dwarf PHLâ5038 in UKIDSS photometry, consistent with the presence of a cool, substellar companion. We have obtained H- and K-grism spectra and images of PHLâ5038 using NIRI on Gemini North. The target is spatially and spectrally resolved into two components: an 8000 K DA white dwarf, and a likely L8 brown dwarf companion, separated by 0.94\arcsec. The spectral type of the secondary was determined using standard spectral indices for late L and T dwarfs. The projected orbital separation of the binary is 55 AU, so it becomes only the second known wide WD+dL binary to be found after GDâ165AB. This object could potentially be used as a benchmark for testing substellar evolutionary models at intermediate to older ages
Clues to the nature of the Delta^*(1700) resonance from pion- and photon-induced reactions
We make a study of the (pi^- p --> K^0 pi^0 Lambda), (pi^+ p --> K^+ pi^+
Lambda), (K^+\bar{K}^0 p), (K^+ pi^+ Sigma^0), (K^+ pi^0 Sigma^+), and (eta
pi^+ p) reactions, in which the basic dynamics is given by the excitation of
the Delta^*(1700) resonance which subsequently decays into (K Sigma^*(1385)) or
(Delta(1232) eta). In a similar way we also study the (gamma p --> K^0 pi^+
Lambda), (K^+ pi^- Sigma^+), (K^+ pi^+ Sigma^-), (K^0 pi^0 Sigma^+), and (eta
pi^0 p) related reactions. The cross sections are proportional to the square of
the coupling of Delta^*(1700) to (Sigma^*K), (Delta eta) for which there is no
experimental information but which is provided in the context of coupled
channels chiral unitary theory where the Delta^*(1700) is dynamically
generated. Within present theoretical and experimental uncertainties one can
claim a global qualitative agreement between theory and experiment. We provide
a list of items which need to be improved in order to make further progress
along these lines.Comment: 11 pages, 5 figure
Modeling the variability of shapes of a human placenta
While it is well-understood what a normal human placenta should look like, a
deviation from the norm can take many possible shapes. In this paper we propose
a mechanism for this variability based on the change in the structure of the
vascular tree
Photo- and Electron-Production of Mesons on Nucleons and Nuclei
In these lectures I will show some results obtained with the chiral unitary
approach applied to the photo and electroproduction of mesons. The results for
photoproduction of and , together with
related reactions will be shown, having with common denominator the excitation
of the resonance which is one of those dynamically generated in
the chiral unitary approach. Then I will show results obtained for the reaction which reproduce the bulk of the data except for a
pronounced peak, giving support to a new mesonic resonance, X(2175). Results
will also be shown for the electromagnetic form factors of the
resonance, also dynamically generated in this approach. Finally, I will show
some results on the photoproduction of the in nuclei, showing that
present experimental results claiming a shift of the mass in the
medium are tied to a particular choice of background and are not conclusive.
One the other hand, the same experimental results show unambiguously a huge
increase of the width in the nuclear medium.Comment: Lecture at the "International School of Nuclear Physics", 29th Course
Quarks in Hadrons and Nuclei, Erice, Italy, September 2007. Note added in
Proofs concerning the mixed events technique and other comments on omega
productio
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