353 research outputs found
Modeling cultural change: computational models of interpersonal influence dynamics can yield new insights about how cultures change, which cultures change more rapidly than others, and why
Cultural change can occur as an emergent consequence of social influence dynamics within cultural populations. These influence dynamics are complex, and formal modeling methods-such as agent-based models-are a useful means of predicting implications for cultural change. These models may be especially useful if they not only model the psychological outcomes of interpersonal influence, but also model social network structures within a culture. When combined, these components provide a flexible modeling framework that allows other variables to also be modeled for the purposes of predicting plausible implications for cultural change. The article illustrates this approach by summarizing recent research that used these methods to model cross-cultural differences in the pace of cultural change. The article then identifies additional variables that could potentially be modeled within this conceptual framework, to produce additional insights-and additional new hypotheses-about different circumstances associated with different patterns of cultural change
Are collectivistic cultures more prone to rapid transformation? Computational models of cross-cultural differences, social network structure, dynamic social influence, and cultural change
Societies differ in susceptibility to social influence and in the social network structure through which individuals influence each other. What implications might these cultural differences have for changes in cultural norms over time? Using parameters informed by empirical evidence, we computationally modeled these cross-cultural differences to predict two forms of cultural change: consolidation of opinion majorities into stronger majorities, and the spread of initially unpopular beliefs. Results obtained from more than 300,000 computer simulations showed that in populations characterized by greater susceptibility to social influence, there was more rapid consolidation of majority opinion and also more successful spread of initially unpopular beliefs. Initially unpopular beliefs also spread more readily in populations characterized by less densely connected social networks. These computational outputs highlight the value of computational modeling methods as a means to specify hypotheses about specific ways in which cross-cultural differences may have long-term consequences for cultural stability and cultural change
Don't cut to the chase: hunting experiences for zoo animals and visitors
This workshop explores different ways to use technology to facilitate hunting behaviour enrichment for zoo-housed animals and parallel gaming experiences for zoo visitors
Dynamical Friction on Star Clusters near the Galactic Center
Numerical simulations of the dynamical friction suffered by a star cluster
near the Galactic center have been performed with a parallelized tree code.
Gerhard (2001) has suggested that dynamical friction, which causes a cluster to
lose orbital energy and spiral in towards the galactic center, may explain the
presence of a cluster of very young stars in the central parsec, where star
formation might be prohibitively difficult owing to strong tidal forces. The
clusters modeled in our simulations have an initial total mass of 10^5-10^6
Msun and initial galactocentric radii of 2.5-30 pc. We have identified a few
simulations in which dynamical friction indeed brings a cluster to the central
parsec, although this is only possible if the cluster is either very massive
(~10^6 Msun), or is formed near the central parsec (<~ 5 pc). In both cases,
the cluster should have an initially very dense core (> 10^6 Msun pc-3). The
initial core collapse and segregation of massive stars into the cluster core,
which typically happens on a much shorter time scale than that characterizing
the dynamical inspiral of the cluster toward the Galactic center, can provide
the requisite high density. Furthermore, because it is the cluster core which
is most likely to survive the cluster disintegration during its journey
inwards, this can help account for the observed distribution of presumably
massive HeI stars in the central parsec.Comment: Accepted for publication in Ap
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Degenerative Cervical Myelopathy: A Brief Review of Past Perspectives, Present Developments, and Future Directions.
Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord injury in developed countries; its prevalence is increasing due to the ageing of the population. DCM causes neurological dysfunction and is a significant cause of disability in the elderly. It has important negative impacts on the quality of life of those affected, as well as on their caregivers. DCM is triggered by a variety of degenerative changes in the neck, which affect one or more anatomical structures, including intervertebral discs, vertebrae, and spinal canal ligaments. These changes can also lead to structural abnormalities, leading to alterations in alignment, mobility, and stability. The principle unifying problem in this disease, regardless of the types of changes present, is injury to the spinal cord due to compression by static and/or dynamic forces. This review is partitioned into three segments that focus on key elements of the past, the present, and the future in the field, which serve to introduce the focus issue on "Degenerative Cervical Myelopathy and the Aging Spine". Emerging from this review is that tremendous progress has been made in the field, particularly in recent years, and that there are exciting possibilities for further advancements of patient care
Developing close combat behaviors for simulated soldiers using genetic programming techniques.
Genetic programming is a powerful methodology for automatically producing solutions to problems in a variety of domains. It has been used successfully to develop behaviors for RoboCup soccer players and simple combat agents. We will attempt to use genetic programming to solve a problem in the domain of strategic combat, keeping in mind the end goal of developing sophisticated behaviors for compound defense and infiltration. The simplified problem at hand is that of two armed agents in a small room, containing obstacles, fighting against each other for survival. The base case and three changes are considered: a memory of positions using stacks, context-dependent genetic programming, and strongly typed genetic programming. Our work demonstrates slight improvements from the first two techniques, and no significant improvement from the last
Sequential Kibble-Zurek dynamics in the anisotropic Ising model of the Si(001) surface
As a simplified description of the non-equilibrium dynamics of buckled dimers
on the Si(001) surface, we consider the anisotropic 2D Ising model and study
the freezing of spatial correlations during a cooling quench across the
critical point. The dependence of the frozen correlation lengths and
on the cooling rate obtained numerically matches the Kibble-Zurek
scaling quite well. However, we also find that the ratio of
their frozen values deviates significantly from the ratio in equilibrium.
Supported by analytical arguments, we explain this difference by the fact that
the deviation from equilibrium in the weakly coupled direction occurs earlier
than in the strongly coupled direction.Comment: 4+2+1 pages, 3 figure
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