15,384 research outputs found
Spartan Daily, February 6, 2018
Volume 150, Issue 5https://scholarworks.sjsu.edu/spartan_daily_2018/1004/thumbnail.jp
Phylogenetic Networks Do not Need to Be Complex: Using Fewer Reticulations to Represent Conflicting Clusters
Phylogenetic trees are widely used to display estimates of how groups of
species evolved. Each phylogenetic tree can be seen as a collection of
clusters, subgroups of the species that evolved from a common ancestor. When
phylogenetic trees are obtained for several data sets (e.g. for different
genes), then their clusters are often contradicting. Consequently, the set of
all clusters of such a data set cannot be combined into a single phylogenetic
tree. Phylogenetic networks are a generalization of phylogenetic trees that can
be used to display more complex evolutionary histories, including reticulate
events such as hybridizations, recombinations and horizontal gene transfers.
Here we present the new CASS algorithm that can combine any set of clusters
into a phylogenetic network. We show that the networks constructed by CASS are
usually simpler than networks constructed by other available methods. Moreover,
we show that CASS is guaranteed to produce a network with at most two
reticulations per biconnected component, whenever such a network exists. We
have implemented CASS and integrated it in the freely available Dendroscope
software
Experimental Study of Remote Job Submission and Execution on LRM through Grid Computing Mechanisms
Remote job submission and execution is fundamental requirement of distributed
computing done using Cluster computing. However, Cluster computing limits usage
within a single organization. Grid computing environment can allow use of
resources for remote job execution that are available in other organizations.
This paper discusses concepts of batch-job execution using LRM and using Grid.
The paper discusses two ways of preparing test Grid computing environment that
we use for experimental testing of concepts. This paper presents experimental
testing of remote job submission and execution mechanisms through LRM specific
way and Grid computing ways. Moreover, the paper also discusses various
problems faced while working with Grid computing environment and discusses
their trouble-shootings. The understanding and experimental testing presented
in this paper would become very useful to researchers who are new to the field
of job management in Grid.Comment: Fourth International Conference on Advanced Computing & Communication
Technologies (ACCT), 201
Spartan Daily, March 26, 2019
Volume 152, Issue 26https://scholarworks.sjsu.edu/spartan_daily_2019/1025/thumbnail.jp
Piecewise Latent Variables for Neural Variational Text Processing
Advances in neural variational inference have facilitated the learning of
powerful directed graphical models with continuous latent variables, such as
variational autoencoders. The hope is that such models will learn to represent
rich, multi-modal latent factors in real-world data, such as natural language
text. However, current models often assume simplistic priors on the latent
variables - such as the uni-modal Gaussian distribution - which are incapable
of representing complex latent factors efficiently. To overcome this
restriction, we propose the simple, but highly flexible, piecewise constant
distribution. This distribution has the capacity to represent an exponential
number of modes of a latent target distribution, while remaining mathematically
tractable. Our results demonstrate that incorporating this new latent
distribution into different models yields substantial improvements in natural
language processing tasks such as document modeling and natural language
generation for dialogue.Comment: 19 pages, 2 figures, 8 tables; EMNLP 201
A high-resolution pointing system for fast scanning platforms: The EBEX example
The E and B experiment (EBEX) is a balloon-borne telescope designed to
measure the polarization of the cosmic microwave background with 8' resolution
employing a gondola scanning with speeds of order degree per second. In January
2013, EBEX completed 11 days of observations in a flight over Antarctica
covering 6000 square degrees of the sky. The payload is equipped with
two redundant star cameras and two sets of three orthogonal gyroscopes to
reconstruct the telescope attitude. The EBEX science goals require the pointing
to be reconstructed to approximately 10" in the map domain, and in-flight
attitude control requires the real time pointing to be accurate to
0.5 . The high velocity scan strategy of EBEX coupled to its float
altitude only permits the star cameras to take images at scan turnarounds,
every 40 seconds, and thus requires the development of a pointing system
with low noise gyroscopes and carefully controlled systematic errors. Here we
report on the design of the pointing system and on a simulation pipeline
developed to understand and minimize the effects of systematic errors. The
performance of the system is evaluated using the 2012/2013 flight data, and we
show that we achieve a pointing error with RMS=25" on 40 seconds azimuth
throws, corresponding to an error of 4.6" in the map domain.Comment: 14 pages, Proceedings of the 2015 IEEE Aerospace Conferenc
Are economic ideas a sustainable commons? A study of the exchange of creative economics
In this essay I claim that productive markets need not necessarily involve clearly defined and enforced property rights, upon which a price system can be used to allocate resources. I shall pursue this thought by an examination of the mechanisms that facilitate the exchange of economic ideas, and link academic norms to the emerging theoretical justification for open source software, and “free culture”.economic ideas, commons, free culture, journals
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