scholarly journals Preference patterns for skewed gambles in rhesus monkeys

2013 ◽  
Vol 9 (6) ◽  
pp. 20130902 ◽  
Author(s):  
Caleb E. Strait ◽  
Benjamin Y. Hayden
Keyword(s):  
Rhesus Monkeys ◽  
Risky Choice ◽  
Process Models ◽  
Statistical Moments ◽  
The Third ◽  
Mean And Variance ◽  
Standard Models ◽  
Preference Patterns ◽  
Third Moment

While standard models of risky choice account for the first and second statistical moments of reward outcome distributions (mean and variance, respectively), they often ignore the third moment, skewness. Determining a decision-maker's attitude about skewness is useful because it can help constrain process models of the mental steps involved in risky choice. We measured three rhesus monkeys’ preferences for gambles whose outcome distributions had almost identical means and variances but differed in skewness. We tested five distributions of skewness: strong negative, weak negative, normal, weak positive and strong positive. Monkeys preferred positively skewed gambles to negatively skewed ones and preferred strongly skewed and normal (i.e. unskewed) gambles to weakly skewed ones. This pattern of preferences cannot be explained solely by monotonic deformations of the utility curve or any other popular single account, but can be accounted for by multiple interacting factors.

Monte Carlo Algorithms for Moments of Transition Arrays

1988 ◽  
Vol 102 ◽  
pp. 79-81
Author(s):  
A. Goldberg ◽  
S.D. Bloom
Keyword(s):  
Monte Carlo ◽  
State Vector ◽  
Basis Vector ◽  
Collective State ◽  
Dispersion Characteristics ◽  
Dipole Strength ◽  
The Third ◽  
Monte Carlo Algorithms ◽  
Third Moment ◽  
Very High

AbstractClosed expressions for the first, second, and (in some cases) the third moment of atomic transition arrays now exist. Recently a method has been developed for getting to very high moments (up to the 12th and beyond) in cases where a “collective” state-vector (i.e. a state-vector containing the entire electric dipole strength) can be created from each eigenstate in the parent configuration. Both of these approaches give exact results. Herein we describe astatistical(or Monte Carlo) approach which requires onlyonerepresentative state-vector |RV> for the entire parent manifold to get estimates of transition moments of high order. The representation is achieved through the random amplitudes associated with each basis vector making up |RV>. This also gives rise to the dispersion characterizing the method, which has been applied to a system (in the M shell) with≈250,000 lines where we have calculated up to the 5th moment. It turns out that the dispersion in the moments decreases with the size of the manifold, making its application to very big systems statistically advantageous. A discussion of the method and these dispersion characteristics will be presented.

scholarly journals PHL 417: a zirconium-rich pulsating hot subdwarf (V366 Aquarid) discovered in K2 data

2020 ◽  
Vol 499 (3) ◽  
pp. 3738-3748
Author(s):  
R H Østensen ◽  
C S Jeffery ◽  
H Saio ◽  
J J Hermes ◽  
J H Telting ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Helium Abundance ◽  
The Sun ◽  
The Third ◽  
Short Period ◽  
Standard Models ◽  
Hot Subdwarfs ◽  
Amplitude Mode ◽  
Rare Group

ABSTRACT The Kepler spacecraft observed the hot subdwarf star PHL 417 during its extended K2 mission, and the high-precision photometric light curve reveals the presence of 17 pulsation modes with periods between 38 and 105 min. From follow-up ground-based spectroscopy, we find that the object has a relatively high temperature of 35 600 K, a surface gravity of $\log g / {\rm cm\, s^{-2}}\, =\, 5.75$ and a supersolar helium abundance. Remarkably, it also shows strong zirconium lines corresponding to an apparent +3.9 dex overabundance compared with the Sun. These properties clearly identify this object as the third member of the rare group of pulsating heavy-metal stars, the V366-Aquarii pulsators. These stars are intriguing in that the pulsations are inconsistent with the standard models for pulsations in hot subdwarfs, which predicts that they should display short-period pulsations rather than the observed longer periods. We perform a stability analysis of the pulsation modes based on data from two campaigns with K2. The highest amplitude mode is found to be stable with a period drift, $\dot{P}$, of less than 1.1 × 10−9 s s−1. This result rules out pulsations driven during the rapid stages of helium flash ignition.

scholarly journals Prospect Theory Reflects Selective Allocation of Attention

2017 ◽  
Author(s):  
Thorsten Pachur ◽  
Michael Schulte-Mecklenbeck
Keyword(s):  
Information Processing ◽  
Individual Differences ◽  
Loss Aversion ◽  
Weighting Function ◽  
Risky Choice ◽  
Process Models ◽  
Attention Allocation ◽  
Psychological Constructs ◽  
Probability Information ◽  
As If

There is a disconnect in the literature between analyses of risky choice based on cumulativeprospect theory (CPT) and work on predecisional information processing. One likely reason is that for expectation models (e.g., CPT) it is often assumed that people only behaved as if they conducted the computations leading to the predicted choice, and that the models are thus mute with regard to information processing. We suggest that key psychological constructs in CPT, such as loss aversion and outcome and probability sensitivity, can be interpreted in terms of attention allocation. In two experiments, we tested hypotheses about specific links between CPT parameters and attentional regularities. Experiment 1 used process tracing to monitor participants’ predecisional attention allocation to outcome and probability information. As hypothesized, individual differences in CPT’s loss-aversion, outcome-sensitivity, and probability-sensitivity parameters (estimated from participants’ choices) were systematically associated with individual differences in attention allocation to outcome and probability information. For instance, loss aversion was associated with the relative attention allocated to loss and gain outcomes, and a more strongly curved weighting function was associated with less attention allocated to probabilities. Experiment 2 manipulated participants’ attention to losses or gains, causing systematic differences in CPT’s loss aversion parameter. This result indicates that attention allocation can to some extent cause choice regularities that are captured by CPT. Our findings demonstrate an “as-if” model’s capacity to reflect characteristics of information processing. We suggest that the observed CPT–attention links can be harnessed to inform the development of process models of risky choice.

Some renewal process models for single neuron discharge

1971 ◽  
Vol 8 (4) ◽  
pp. 802-808 ◽  
Author(s):  
Howard G. Hochman ◽  
Stephen E. Fienberg
Keyword(s):  
Single Neuron ◽  
Interspike Interval ◽  
Poisson Processes ◽  
Process Models ◽  
Recurrence Time ◽  
The Laplace Transform ◽  
Mean And Variance ◽  
The Mean ◽  
Interspike Interval Distribution ◽  
Interval Distribution

Leslie (1969) obtained the Laplace transform for the recurrence time of clusters of Poisson processes, which can be thought of as yielding the interspike interval distribution for a neuron that receives Poisson excitatory inputs subject to decay. Here, several extensions of this model are derived, each including Poisson inhibitory inputs. Expressions for the mean and variance are derived for each model, and the results for the different models are compared.

The significance of the third moment in the apparent size method

2000 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Lu Zhang ◽  
R. Bahreini ◽  
J.W. Gentry
Keyword(s):  
Apparent Size ◽  
The Third ◽  
Third Moment

The Assessment of Nocturnal Oxygen Saturation

1983 ◽  
Vol 65 (5) ◽  
pp. 507-513
Author(s):  
C. I. Meanock ◽  
A. R. Guyatt ◽  
G. Cumming
Keyword(s):  
Oxygen Saturation ◽  
Air Flow ◽  
Digital Processing ◽  
Moment Analysis ◽  
Good Reproducibility ◽  
The Third ◽  
Simple Index ◽  
The Mean ◽  
Single Figure ◽  
Third Moment

1. Existing methods of assessing nocturnal episodic hypoxaemia are either insensitive or ignore the majority of the available data. 2. We describe a method of analysis using offline digital processing. A distribution of oxygen saturation (Sao2) with time is produced from all the available data, and subjected to moment analysis to produce a simple index which describes an entire night's Sao2. 3. Our results suggest that the mean and the coefficient of skew fully described a night's Sao2. However, in subjects with chronic air-flow obstruction, the third moment about 100% oxygen saturation (M3100), a single figure, has the same descriptive power as mean and skew. 4. In 17 subjects with chronic air-flow obstruction a significant correlation was found between both daytime Sao2 and Paco2 when plotted against either the M3100 or the skew. 5. Measurements made on two occasions in seven subjects showed good reproducibility for the skew and M3100 indices.

scholarly journals Model of qubits as devices to detect the third moment of current fluctuations

2006 ◽  
Vol 74 (2) ◽  
Author(s):  
Valentina Brosco ◽  
Rosario Fazio ◽  
F. W. J. Hekking ◽  
J. P. Pekola
Keyword(s):  
Current Fluctuations ◽  
The Third ◽  
Third Moment

Determination of relevant “average” properties for tubular filler materials used in composites

2011 ◽  
Vol 31 (4) ◽  
Author(s):  
Patrick M. Piccione
Keyword(s):  
Carbon Nanotubes ◽  
Average Diameter ◽  
Weighting Factor ◽  
Filler Materials ◽  
Cross Sectional ◽  
The Third ◽  
Materials Used ◽  
Third Moment ◽  
Calculation Procedures

Abstract To obtain the best estimate of the average diameter and number of walls of tubular objects such as carbon nanotubes, which are used as filler materials in composites, both inner and outer diameters must be taken into consideration. The appropriate weighting factor is calculated from the cross-sectional circular shell area. In the case of cylindrical objects, the formulae simplify considerably and the average diameter and wall thickness are the third moment of their distribution function. Two examples illustrate the numerical effects of these calculation procedures.

Probabilistic Model of Corrosion in Reinforced Concrete Structures Considering Coupling Effects of Influence Factors

2013 ◽  
Vol 671-674 ◽  
pp. 740-745
Author(s):  
Xiao Gang Zhang ◽  
Jiao Wang
Keyword(s):  
Probabilistic Model ◽  
Moment Method ◽  
Influence Factors ◽  
Concrete Structures ◽  
Chloride Concentration ◽  
Corrosion Process ◽  
Chloride Ingress ◽  
Coupling Effects ◽  
The Third ◽  
Third Moment

A probabilistic model of the chloride-induced corrosion process is provided in this paper. Based on the Third-moment method, the uncertainty of various influence factors and the coupling effects of them are concerned. Considering the corrosion process as a statistic process, the probability of corrosion initiation at certain time can be obtained. Moreover, the effect of micro-crack in chloride ingress is taken into account, too. Due to the results of stochastic analysis, the surface chloride concentration is the most important factor that affects the corrosion probability, while the thickness of concrete cover, chloride diffusion coefficient, environmental relative humidity, critical threshold chloride concentration, micro-crack rate, water-to-cement ratio and temperature are also important factors. And the Third-moment method is proved to be reasonable in the durability assessment of corrosion-induced concrete structure. The results in this paper can be used to predict the rest life of corrosion-induced concrete structures.

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