4,112 research outputs found
A comparison of two trusses for the space station structure
The structural performance of two truss configurations, the orthogonal tetrahedral and a Warren-type, are compared using finite element models representing the November Reference Phase 1 Space Station. The truss torsional stiffness properties and fundamental torsion frequency are determined using cantilever truss-beam models. Frequencies, mode shapes, transient response, and truss strut compressive loads are compared for the two space station models. The performance benefit resulting from using a high modulus truss strut is also presented. Finally, assembly and logistics characteristics of the two truss configurations are evaluated
Psychological pressure in competitive environments: Evidence from a randomized natural experiment: Comment
Apesteguia and Palacios-Huerta (forthcoming) report for a sample of 129 shootouts from various seasons in ten different competitions that teams kicking first in soccer penalty shootouts win significantly more often than teams kicking second. Collecting data for the entire history of six major soccer competitions we cannot replicate their result. Teams kicking first win only 53.4% of 262 shootouts in our data, which is not significantly different from random. Our findings have two implications: (1) Apesteguia and Palacios-Huerta’s results are not generally robust. (2) Using specific subsamples without a coherent criterion for data selection might lead to non-representative findings
Revealed Distributional Preferences: Individuals vs. Teams
We compare experimentally the revealed distributional preferences of individuals and teams in allocation tasks. We find that teams are significantly more benevolent than individuals in the domain of disadvantageous inequality while the benevolence in the domain of advantageous inequality is similar across decision makers. A consequence for the frequency of preference types is that while a substantial fraction of individuals is classified as inequality averse, this type disappears completely in teams. Spiteful types are markedly more frequent among individuals than among teams. On the other hand, by far more teams than individuals are classified as efficiency lovers
Psychological pressure in competitive environments: Evidence from a randomized natural experiment: Comment
Apesteguia and Palacios-Huerta (forthcoming) report for a sample of 129 shootouts from various seasons in ten different competitions that teams kicking first in soccer penalty shootouts win significantly more often than teams kicking second. Collecting data for the entire history of six major soccer competitions we cannot replicate their result. Teams kicking first win only 53.4% of 262 shootouts in our data, which is not significantly different from random. Our findings have two implications: (1) Apesteguia and Palacios-Huerta's results are not generally robust. (2) Using specific subsamples without a coherent criterion for data selection might lead to non-representative findings.Tournament, first-mover advantage, psychological pressure, field experiment, soccer, penalty shootouts
El auge de China y la continuidad de la hegemonía de EEUU en Asia
En este ARI el autor afirma que la fortaleza de China como potencia emergente en Asia se ha sobrevalorado, mientras que el poder y la influencia general de EEUU en la zona no ha declinado.
Este análisis se plantea como respuesta a la gran variedad de valoraciones y opiniones de los medios, especialistas y expertos que describen un orden asiático emergente encabezado por una China en auge y que relegan a EEUU –que ha mantenido durante largo tiempo el liderazgo en la zona– a un papel cada vez más secundario. En él se demuestra que estas valoraciones y comentarios tienden a sobrevalorar tanto la fuerza de la potencia emergente, China, como la debilidad de EEUU. Este planteamiento es similar al adoptado en otras ocasiones de la historia reciente y que condujo a valoraciones muy erróneas del desafío al liderazgo norteamericano en Asia que representaron la Unión Soviética a finales de la década de los 70 y el auge de Japón durante la década de los 80
Psychological Pressure in Competitive Environments: Evidence from a Randomized Natural Experiment: Comment
Apesteguia and Palacios-Huerta (forthcoming) report for a sample of 129 shootouts from various seasons in ten different competitions that teams kicking first in soccer penalty shootouts win significantly more often than teams kicking second. Collecting data for the entire history of six major soccer competitions we cannot replicate their result. Teams kicking first win only 53.4% of 262 shootouts in our data, which is not significantly different from random. Our findings have two implications: (1) Apesteguia and Palacios-Huerta's results are not generally robust. (2) Using specific subsamples without a coherent criterion for data selection might lead to non-representative findings.tournament, first-mover advantage, psychological pressure, field experiment, soccer, penalty shootouts
Psychological pressure in competitive environments: Evidence from a randomized natural experiment: Comment
Apesteguia and Palacios-Huerta (forthcoming) report for a sample of 129 shootouts from various seasons in ten different competitions that teams kicking first in soccer penalty shootouts win significantly more often than teams kicking second. Collecting data for the entire history of six major soccer competitions we cannot replicate their result. Teams kicking first win only 53.4% of 262 shootouts in our data, which is not significantly different from random. Our findings have two implications: (1) Apesteguia and Palacios-Huerta?s results are not generally robust. (2) Using specific subsamples without a coherent criterion for data selection might lead to non-representative findings.Tournament, first-mover advantage, psychological pressure, field experiment, soccer, penalty shootouts
Psychological pressure in competitive environments: Evidence from a randomized natural experiment: Comment
Apesteguia and Palacios-Huerta (forthcoming) report for a sample of 129 shootouts from various seasons in ten different competitions that teams kicking first in soccer penalty shootouts win significantly more often than teams kicking second. Collecting data for the entire history of six major soccer competitions we cannot replicate their result. Teams kicking first win only 53.4% of 262 shootouts in our data, which is not significantly different from random. Our findings have two implications: (1) Apesteguia and Palacios-Huerta’s results are not generally robust. (2) Using specific subsamples without a coherent criterion for data selection might lead to non-representative findings.Tournament; first-mover advantage; psychological pressure; field experiment; soccer; penalty shootouts
Impatience and Uncertainty: Experimental Decisions Predict Adolecents' Field Behavior
We study risk attitudes, ambiguity attitudes, and time preferences of 661 children and
adolescents, aged ten to eighteen years, in an incentivized experiment. We relate experimental
choices to field behavior. Experimental measures of impatience are found to be significant
predictors of health related field behavior and saving decisions. In particular, more impatient
children and adolescents are more likely to spend money on alcohol and cigarettes, have a higher
body mass index (BMI) and are less likely to save money. Experimental measures for risk and
ambiguity attitudes are only weak predictors of field behavior
A variational approach to moment-closure approximations for the kinetics of biomolecular reaction networks
Approximate solutions of the chemical master equation and the chemical
Fokker-Planck equation are an important tool in the analysis of biomolecular
reaction networks. Previous studies have highlighted a number of problems with
the moment-closure approach used to obtain such approximations, calling it an
ad-hoc method. In this article, we give a new variational derivation of
moment-closure equations which provides us with an intuitive understanding of
their properties and failure modes and allows us to correct some of these
problems. We use mixtures of product-Poisson distributions to obtain a flexible
parametric family which solves the commonly observed problem of divergences at
low system sizes. We also extend the recently introduced entropic matching
approach to arbitrary ansatz distributions and Markov processes, demonstrating
that it is a special case of variational moment closure. This provides us with
a particularly principled approximation method. Finally, we extend the above
approaches to cover the approximation of multi-time joint distributions,
resulting in a viable alternative to process-level approximations which are
often intractable.Comment: Minor changes and clarifications; corrected some typo
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