2,146 research outputs found
Current Studies and Applications of Krill Herd and Gravitational Search Algorithms in Healthcare
Nature-Inspired Computing or NIC for short is a relatively young field that
tries to discover fresh methods of computing by researching how natural
phenomena function to find solutions to complicated issues in many contexts. As
a consequence of this, ground-breaking research has been conducted in a variety
of domains, including synthetic immune functions, neural networks, the
intelligence of swarm, as well as computing of evolutionary. In the domains of
biology, physics, engineering, economics, and management, NIC techniques are
used. In real-world classification, optimization, forecasting, and clustering,
as well as engineering and science issues, meta-heuristics algorithms are
successful, efficient, and resilient. There are two active NIC patterns: the
gravitational search algorithm and the Krill herd algorithm. The study on using
the Krill Herd Algorithm (KH) and the Gravitational Search Algorithm (GSA) in
medicine and healthcare is given a worldwide and historical review in this
publication. Comprehensive surveys have been conducted on some other
nature-inspired algorithms, including KH and GSA. The various versions of the
KH and GSA algorithms and their applications in healthcare are thoroughly
reviewed in the present article. Nonetheless, no survey research on KH and GSA
in the healthcare field has been undertaken. As a result, this work conducts a
thorough review of KH and GSA to assist researchers in using them in diverse
domains or hybridizing them with other popular algorithms. It also provides an
in-depth examination of the KH and GSA in terms of application, modification,
and hybridization. It is important to note that the goal of the study is to
offer a viewpoint on GSA with KH, particularly for academics interested in
investigating the capabilities and performance of the algorithm in the
healthcare and medical domains.Comment: 35 page
Cloud Service Selection System Approach based on QoS Model: A Systematic Review
The Internet of Things (IoT) has received a lot of interest from researchers recently. IoT is seen as a component of the Internet of Things, which will include billions of intelligent, talkative "things" in the coming decades. IoT is a diverse, multi-layer, wide-area network composed of a number of network links. The detection of services and on-demand supply are difficult in such networks, which are comprised of a variety of resource-limited devices. The growth of service computing-related fields will be aided by the development of new IoT services. Therefore, Cloud service composition provides significant services by integrating the single services. Because of the fast spread of cloud services and their different Quality of Service (QoS), identifying necessary tasks and putting together a service model that includes specific performance assurances has become a major technological problem that has caused widespread concern. Various strategies are used in the composition of services i.e., Clustering, Fuzzy, Deep Learning, Particle Swarm Optimization, Cuckoo Search Algorithm and so on. Researchers have made significant efforts in this field, and computational intelligence approaches are thought to be useful in tackling such challenges. Even though, no systematic research on this topic has been done with specific attention to computational intelligence. Therefore, this publication provides a thorough overview of QoS-aware web service composition, with QoS models and approaches to finding future aspects
SkyDOT (Sky Database for Objects in the Time Domain): A Virtual Observatory for Variability Studies at LANL
The mining of Virtual Observatories (VOs) is becoming a powerful new method
for discovery in astronomy. Here we report on the development of SkyDOT (Sky
Database for Objects in the Time domain), a new Virtual Observatory, which is
dedicated to the study of sky variability. The site will confederate a number
of massive variability surveys and enable exploration of the time domain in
astronomy. We discuss the architecture of the database and the functionality of
the user interface. An important aspect of SkyDOT is that it is continuously
updated in near real time so that users can access new observations in a timely
manner. The site will also utilize high level machine learning tools that will
allow sophisticated mining of the archive. Another key feature is the real time
data stream provided by RAPTOR (RAPid Telescopes for Optical Response), a new
sky monitoring experiment under construction at Los Alamos National Laboratory
(LANL).Comment: to appear in SPIE proceedings vol. 4846, 11 pages, 5 figure
Direct Observation of Cosmic Strings via their Strong Gravitational Lensing Effect: II. Results from the HST/ACS Image Archive
We have searched 4.5 square degrees of archival HST/ACS images for cosmic
strings, identifying close pairs of similar, faint galaxies and selecting
groups whose alignment is consistent with gravitational lensing by a long,
straight string. We find no evidence for cosmic strings in five large-area HST
treasury surveys (covering a total of 2.22 square degrees), or in any of 346
multi-filter guest observer images (1.18 square degrees). Assuming that
simulations ccurately predict the number of cosmic strings in the universe,
this non-detection allows us to place upper limits on the unitless Universal
cosmic string tension of G mu/c^2 < 2.3 x 10^-6, and cosmic string density of
Omega_s < 2.1 x 10^-5 at the 95% confidence level (marginalising over the other
parameter in each case). We find four dubious cosmic string candidates in 318
single filter guest observer images (1.08 square degrees), which we are unable
to conclusively eliminate with existing data. The confirmation of any one of
these candidates as cosmic strings would imply G mu/c^2 ~ 10^-6 and Omega_s ~
10^-5. However, we estimate that there is at least a 92% chance that these
string candidates are random alignments of galaxies. If we assume that these
candidates are indeed false detections, our final limits on G mu/c^2 and
Omega_s fall to 6.5 x 10^-7 and 7.3 x 10^-6. Due to the extensive sky coverage
of the HST/ACS image archive, the above limits are universal. They are quite
sensitive to the number of fields being searched, and could be further reduced
by more than a factor of two using forthcoming HST data.Comment: 21 pages, 18 figure
Metaheuristic design of feedforward neural networks: a review of two decades of research
Over the past two decades, the feedforward neural network (FNN) optimization has been a key interest among the researchers and practitioners of multiple disciplines. The FNN optimization is often viewed from the various perspectives: the optimization of weights, network architecture, activation nodes, learning parameters, learning environment, etc. Researchers adopted such different viewpoints mainly to improve the FNN's generalization ability. The gradient-descent algorithm such as backpropagation has been widely applied to optimize the FNNs. Its success is evident from the FNN's application to numerous real-world problems. However, due to the limitations of the gradient-based optimization methods, the metaheuristic algorithms including the evolutionary algorithms, swarm intelligence, etc., are still being widely explored by the researchers aiming to obtain generalized FNN for a given problem. This article attempts to summarize a broad spectrum of FNN optimization methodologies including conventional and metaheuristic approaches. This article also tries to connect various research directions emerged out of the FNN optimization practices, such as evolving neural network (NN), cooperative coevolution NN, complex-valued NN, deep learning, extreme learning machine, quantum NN, etc. Additionally, it provides interesting research challenges for future research to cope-up with the present information processing era
Binary Quasars in the Sloan Digital Sky Survey: Evidence for Excess Clustering on Small Scales
We present a sample of 218 new quasar pairs with proper transverse
separations R_prop < 1 Mpc/h over the redshift range 0.5 < z < 3.0, discovered
from an extensive follow up campaign to find companions around the Sloan
Digital Sky Survey and 2dF Quasar Redshift Survey quasars. This sample includes
26 new binary quasars with separations R_prop < 50 kpc/h (theta < 10
arcseconds), more than doubling the number of such systems known. We define a
statistical sample of binaries selected with homogeneous criteria and compute
its selection function, taking into account sources of incompleteness. The
first measurement of the quasar correlation function on scales 10 kpc/h <
R_prop < 400 kpc/h is presented. For R_prop < 40 kpc/h, we detect an order of
magnitude excess clustering over the expectation from the large scale R_prop >
3 Mpc/h quasar correlation function, extrapolated down as a power law to the
separations probed by our binaries. The excess grows to ~ 30 at R_prop ~ 10
kpc/h, and provides compelling evidence that the quasar autocorrelation
function gets progressively steeper on sub-Mpc scales. This small scale excess
can likely be attributed to dissipative interaction events which trigger quasar
activity in rich environments. Recent small scale measurements of galaxy
clustering and quasar-galaxy clustering are reviewed and discussed in relation
to our measurement of small scale quasar clustering.Comment: 25 pages, 12 figures, 9 tables. Submitted to the Astronomical Journa
Massive Datasets in Astronomy
Astronomy has a long history of acquiring, systematizing, and interpreting
large quantities of data. Starting from the earliest sky atlases through the
first major photographic sky surveys of the 20th century, this tradition is
continuing today, and at an ever increasing rate.
Like many other fields, astronomy has become a very data-rich science, driven
by the advances in telescope, detector, and computer technology. Numerous large
digital sky surveys and archives already exist, with information content
measured in multiple Terabytes, and even larger, multi-Petabyte data sets are
on the horizon. Systematic observations of the sky, over a range of
wavelengths, are becoming the primary source of astronomical data. Numerical
simulations are also producing comparable volumes of information. Data mining
promises to both make the scientific utilization of these data sets more
effective and more complete, and to open completely new avenues of astronomical
research.
Technological problems range from the issues of database design and
federation, to data mining and advanced visualization, leading to a new toolkit
for astronomical research. This is similar to challenges encountered in other
data-intensive fields today.
These advances are now being organized through a concept of the Virtual
Observatories, federations of data archives and services representing a new
information infrastructure for astronomy of the 21st century. In this article,
we provide an overview of some of the major datasets in astronomy, discuss
different techniques used for archiving data, and conclude with a discussion of
the future of massive datasets in astronomy.Comment: 46 Pages, 21 Figures, Invited Review for the Handbook of Massive
Datasets, editors J. Abello, P. Pardalos, and M. Resende. Due to space
limitations this version has low resolution figures. For full resolution
review see http://www.astro.caltech.edu/~rb/publications/hmds.ps.g
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