7,475 research outputs found
Innovative spatial timber structures: workshops with physical modeling explorations from small to full scale
Architects and Engineers are educated and work within two separate cultures yet
they are both concerned with conceptual structural design. The collaboration between
the professions is especially important when designing buildings where the structure to
a great degree forms the spaces, as in the cases of form generating structures such as
gridshells, reciprocal frames, space trusses etc . This paper describes several specialist
research based workshops developed at KA over the last two years that use physical
modelling of 1:1 innovative timber load-bearing structures such as gridshells and
reciprocal frames
Supernova Blastwaves in Low-density Hot Media: a Mechanism for Spatially Distributed Heating
Most supernovae are expected to explode in low-density hot media,
particularly in galactic bulges and elliptical galaxies. The remnants of such
supernovae, though difficult to detect individually, can be profoundly
important in heating the media on large scales. We characterize the evolution
of this kind of supernova remnants, based on analytical approximations and
hydrodynamic simulations. We generalize the standard Sedov solution to account
for both temperature and density effects of the ambient media. Although cooling
can be neglected, the expansion of such a remnant deviates quickly from the
standard Sedov solution and asymptotically approaches the ambient sound speed
as the swept-up thermal energy becomes important. The relatively steady and
fast expansion of the remnants over large volumes provides an ideal mechanism
for spatially distributed heating, which may help to alleviate the over-cooling
problem of hot gas in groups and clusters of galaxies as well as in galaxies
themselves. The simulations were performed with the FLASH code.Comment: 12 pages, 3 figures, 1 table, accepted for ApJ, uses aaste
Universally Consistent Latent Position Estimation and Vertex Classification for Random Dot Product Graphs
In this work we show that, using the eigen-decomposition of the adjacency
matrix, we can consistently estimate latent positions for random dot product
graphs provided the latent positions are i.i.d. from some distribution. If
class labels are observed for a number of vertices tending to infinity, then we
show that the remaining vertices can be classified with error converging to
Bayes optimal using the -nearest-neighbors classification rule. We evaluate
the proposed methods on simulated data and a graph derived from Wikipedia
Scalability of Hydrodynamic Simulations
Many hydrodynamic processes can be studied in a way that is scalable over a
vastly relevant physical parameter space. We systematically examine this
scalability, which has so far only briefly discussed in astrophysical
literature. We show how the scalability is limited by various constraints
imposed by physical processes and initial conditions. Using supernova remnants
in different environments and evolutionary phases as application examples, we
demonstrate the use of the scaling as a powerful tool to explore the
interdependence among relevant parameters, based on a minimum set of
simulations. In particular, we devise a scaling scheme that can be used to
adaptively generate numerous seed remnants and plant them into 3D hydrodynamic
simulations of the supernova-dominated interstellar medium.Comment: 12 pages, 1 figure, submitted to MNRAS; comments are welcom
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