87 research outputs found
Analysis of Fermi-LAT data from Tucana-II: Possible constraints on the Dark Matter models with an intriguing hint of a signal
Tucana-II (Tuc-II), a recently discovered and confirmed Ultra Faint Dwarf
Spheroidal galaxy, has a high mass to light ratio as well as a large
line-of-sight stellar velocity dispersion, thus making it an ideal candidate
for an indirect dark matter (DM) search. In this paper, we have analyzed nine
years of -ray data obtained from the \textit{Fermi}-LAT instrument from
the direction of Tuc-II. The fact that a very weak significant -ray
excess () over the background of Tuc-II have been detected from the
location of this galaxy. We have observed that this excess of -ray
emission from the of location Tuc-II rises with longer periods of data. If WIMP
pair annihilation is assumed for this faint emission, for
annihilation channel the test statistics (TS) value peaks at DM mass 14
GeV and for annihilation channel it peaks at DM mass 4 GeV.
It is then called for an estimation of the confidence level upper limit
of the possible velocity weighted self-annihilation cross-section of the DM
particles (WIMPs) within Tuc-II by fitting the observed -ray flux with
spectra expected for DM annihilation. The estimated upper limits of the
cross-sections from Tuc-II are then compared with two other dwarf galaxies that
are considered to be good DM candidates in several studies. We have also
compared our results with the cross-sections obtained in various popular
theoretical models of the WIMPs to find that our results impose reasonable
tight constraints on the parameter spaces of those DM models. In the concluding
section, we compared our results with the similar results obtained from a
combined dSph analysis by the \textit{Fermi}-LAT collaboration as well as the
results obtained from the studies of DM in the dwarf galaxies by the major
ground-based Cherenkov experiments.Comment: 23 pages, 16 figures, 7 table
Application of artificial neural network in market segmentation: A review on recent trends
Despite the significance of Artificial Neural Network (ANN) algorithm to
market segmentation, there is a need of a comprehensive literature review and a
classification system for it towards identification of future trend of market
segmentation research. The present work is the first identifiable academic
literature review of the application of neural network based techniques to
segmentation. Our study has provided an academic database of literature between
the periods of 2000-2010 and proposed a classification scheme for the articles.
One thousands (1000) articles have been identified, and around 100 relevant
selected articles have been subsequently reviewed and classified based on the
major focus of each paper. Findings of this study indicated that the research
area of ANN based applications are receiving most research attention and self
organizing map based applications are second in position to be used in
segmentation. The commonly used models for market segmentation are data mining,
intelligent system etc. Our analysis furnishes a roadmap to guide future
research and aid knowledge accretion and establishment pertaining to the
application of ANN based techniques in market segmentation. Thus the present
work will significantly contribute to both the industry and academic research
in business and marketing as a sustainable valuable knowledge source of market
segmentation with the future trend of ANN application in segmentation.Comment: 24 pages, 7 figures,3 Table
Smart Knowledge Transfer using Google-like Search
To address the issue of rising software maintenance cost due to program
comprehension challenges, we propose SMARTKT (Smart Knowledge Transfer), a
search framework, which extracts and integrates knowledge related to various
aspects of an application in form of a semantic graph. This graph supports
syntax and semantic queries and converts the process of program comprehension
into a {\em google-like} search problem.Comment: 3 pages, 2 figures, accepted in the NDLI-UNESCO International
Symposium on Knowledge Engineering for Digital Library Design 2019 (KEDL) as
an extended abstract and poste
Investigating the region of 3C 397 in High Energy Gamma rays
We investigate the supernova remnant (SNR) 3C 397 and its neighboring pulsar
PSR J1906+0722 in high energy gamma rays by using nearly six years of archival
data of {\it Large Area Telescope} on board {\it Fermi Gamma Ray Space
Telescope} (Fermi-LAT). The off-pulse analysis of gamma-ray flux from the
location of PSR J1906+0722 reveals an excess emission which is found to be very
close to the radio location of 3C 397. Here, we present the preliminary results
of this gamma-ray analysis of 3C 397 and PSR J1906+0722.Comment: 4 pages, 3 figures, Proceeding of IAU Symposium No. 331, 201
Implementation of Mobile Technology in Academic Library of Siliguri Subdivision Govt. Aided General Degree Colleges: A Study
This paper highlights the present trends and developments for using mobile technology in academic libraries which has its grate impact on the libraries of the modern society. The library and information services are rapidly changing and it has developed in the 21st century more effectively in the digital era. Libraries have the well opportunity to extend new different types of library services to users. The digital technology has made it easy to store, use, share immediately and instantly by the users demands. The main purpose of this study is to implement mobile technology in academic library of siliguri subdivision in general degree colleges generally and particularly effective utilize in libraries and library services
Implementation of Mobile Technology in Academic Library of Siliguri Subdivision Govt. Aided General Degree Colleges: A Study
This paper highlights the present trends and developments for using mobile technology in academic libraries which has its grate impact on the libraries of the modern society. The library and information services are rapidly changing and it has developed in the 21st century more effectively in the digital era. Libraries have the well opportunity to extend new different types of library services to users. The digital technology has made it easy to store, use, share immediately and instantly by the users demands. The main purpose of this study is to implement mobile technology in academic library of siliguri subdivision in general degree colleges generally and particularly effective utilize in libraries and library services
Reduction in turbulence-induced non-linear dynamic vibration using tuned liquid damper (TLD)
In the present research work, an attempt is made to develop a coupled
non-linear turbulence-structure-damper model in a finite volume-finite
difference (FV-FD) framework. Tuned liquid damper (TLD) is used as the
additional damping system along with inherent structural damping. Real-time
simulation of flow-excited bridge box girder or chimney section and the
vibration reduction using TLD can be performed using the developed model. The
turbulent flow field around a structure is modeled using an OpenFOAM transient
PISO solver, and the time-varying drag force is calculated. This force perturbs
the structure, causing the sloshing phenomena of the attached TLD, modeled
using shallow depth approximation, damping the flow-induced vibration of the
structure. The structural motion with and without the attached TLD is modeled
involving the FD-based Newmark-Beta method using in-house MATLAB codes. The TLD
is tuned with the vortex-shedding frequency of the low-Reynolds number flows,
and it is found to be reducing the structural excitation significantly. On the
other hand, the high-Reynolds number turbulent flow exhibits a broadband
excitation, for which by tuning the TLD with few frequencies obtained through
investigations, a good reduction in vibration is observed.Comment: 6 pages, 12 figure
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