1,565 research outputs found
Semantic Query Optimisation with Ontology Simulation
Semantic Web is, without a doubt, gaining momentum in both industry and
academia. The word "Semantic" refers to "meaning" - a semantic web is a web of
meaning. In this fast changing and result oriented practical world, gone are
the days where an individual had to struggle for finding information on the
Internet where knowledge management was the major issue. The semantic web has a
vision of linking, integrating and analysing data from various data sources and
forming a new information stream, hence a web of databases connected with each
other and machines interacting with other machines to yield results which are
user oriented and accurate. With the emergence of Semantic Web framework the
na\"ive approach of searching information on the syntactic web is clich\'e.
This paper proposes an optimised semantic searching of keywords exemplified by
simulation an ontology of Indian universities with a proposed algorithm which
ramifies the effective semantic retrieval of information which is easy to
access and time saving
C-Planarity Testing of Embedded Clustered Graphs with Bounded Dual Carving-Width
For a clustered graph, i.e, a graph whose vertex set is recursively
partitioned into clusters, the C-Planarity Testing problem asks whether it is
possible to find a planar embedding of the graph and a representation of each
cluster as a region homeomorphic to a closed disk such that 1. the subgraph
induced by each cluster is drawn in the interior of the corresponding disk, 2.
each edge intersects any disk at most once, and 3. the nesting between clusters
is reflected by the representation, i.e., child clusters are properly contained
in their parent cluster. The computational complexity of this problem, whose
study has been central to the theory of graph visualization since its
introduction in 1995 [Qing-Wen Feng, Robert F. Cohen, and Peter Eades.
Planarity for clustered graphs. ESA'95], has only been recently settled
[Radoslav Fulek and Csaba D. T\'oth. Atomic Embeddability, Clustered Planarity,
and Thickenability. To appear at SODA'20]. Before such a breakthrough, the
complexity question was still unsolved even when the graph has a prescribed
planar embedding, i.e, for embedded clustered graphs.
We show that the C-Planarity Testing problem admits a single-exponential
single-parameter FPT algorithm for embedded clustered graphs, when
parameterized by the carving-width of the dual graph of the input. This is the
first FPT algorithm for this long-standing open problem with respect to a
single notable graph-width parameter. Moreover, in the general case, the
polynomial dependency of our FPT algorithm is smaller than the one of the
algorithm by Fulek and T\'oth. To further strengthen the relevance of this
result, we show that the C-Planarity Testing problem retains its computational
complexity when parameterized by several other graph-width parameters, which
may potentially lead to faster algorithms.Comment: Extended version of the paper "C-Planarity Testing of Embedded
Clustered Graphs with Bounded Dual Carving-Width" to appear in the
Proceedings of the 14th International Symposium on Parameterized and Exact
Computation (IPEC 2019
The TimeGeo modeling framework for urban motility without travel surveys
Well-established fine-scale urban mobility models today depend on detailed but cumbersome and expensive travel surveys for their calibration. Not much is known, however, about the set of mechanisms needed to generate complete mobility profiles if only using passive datasets with mostly sparse traces of individuals. In this study, we present a mechanistic modeling framework (TimeGeo) that effectively generates urban mobility patterns with resolution of 10 min and hundreds of meters. It ties together the inference of home and work activity locations from data, with the modeling of flexible activities (e.g., other) in space and time. The temporal choices are captured by only three features: the weekly home-based tour number, the dwell rate, and the burst rate. These combined generate for each individual: (i) stay duration of activities, (ii) number of visited locations per day, and (iii) daily mobility networks. These parameters capture how an individual deviates from the circadian rhythm of the population, and generate the wide spectrum of empirically observed mobility behaviors. The spatial choices of visited locations are modeled by a rank-based exploration and preferential return (r-EPR) mechanism that incorporates space in the EPR model. Finally, we show that a hierarchical multiplicative cascade method can measure the interaction between land use and generation of trips. In this way, urban structure is directly related to the observed distance of travels. This framework allows us to fully embrace the massive amount of individual data generated by information and communication technologies (ICTs) worldwide to comprehensively model urban mobility without travel surveys
Room Temperature Intrinsic Ferromagnetism in Epitaxial Manganese Selenide Films in the Monolayer Limit
Monolayer van der Waals (vdW) magnets provide an exciting opportunity for
exploring two-dimensional (2D) magnetism for scientific and technological
advances, but the intrinsic ferromagnetism has only been observed at low
temperatures. Here, we report the observation of room temperature
ferromagnetism in manganese selenide (MnSe) films grown by molecular beam
epitaxy (MBE). Magnetic and structural characterization provides strong
evidence that in the monolayer limit, the ferromagnetism originates from a vdW
manganese diselenide (MnSe) monolayer, while for thicker films it could
originate from a combination of vdW MnSe and/or interfacial magnetism of
-MnSe(111). Magnetization measurements of monolayer MnSe films on
GaSe and SnSe epilayers show ferromagnetic ordering with large saturation
magnetization of ~ 4 Bohr magnetons per Mn, which is consistent with density
functional theory calculations predicting ferromagnetism in monolayer
1T-MnSe. Growing MnSe films on GaSe up to high thickness (~ 40 nm)
produces -MnSe(111), and an enhanced magnetic moment (~ 2x) compared to
the monolayer MnSe samples. Detailed structural characterization by
scanning transmission electron microscopy (STEM), scanning tunneling microscopy
(STM), and reflection high energy electron diffraction (RHEED) reveal an abrupt
and clean interface between GaSe(0001) and -MnSe(111). In particular,
the structure measured by STEM is consistent with the presence of a MnSe
monolayer at the interface. These results hold promise for potential
applications in energy efficient information storage and processing
Redesigning Pricing Systems for E-Commerce Platforms: A Case Study in Backend Optimization
The dynamic nature of e-commerce requires adaptable and efficient pricing systems to meet the demands of competitive markets. This study presents a comprehensive approach to redesigning pricing systems for e-commerce platforms with a focus on backend optimization. By analyzing the limitations of traditional pricing architectures, we propose a robust framework that leverages microservices, scalable databases, and machine learning algorithms to enhance pricing accuracy and agility. The redesign emphasizes modularity, enabling real-time price adjustments based on market trends, inventory levels, and consumer behavior. A case study of an e-commerce platform\u27s transition to the proposed system demonstrates significant improvements in performance metrics, including reduced latency, increased system reliability, and enhanced revenue growth. This research highlights the importance of integrating advanced technologies and streamlined backend processes to sustain a competitive edge in the e-commerce industry. The findings serve as a guide for businesses aiming to modernize their pricing systems and align them with evolving market dynamics
Genome-Wide Profiling of Pluripotent Cells Reveals a Unique Molecular Signature of Human Embryonic Germ Cells
Human embryonic germ cells (EGCs) provide a powerful model for identifying molecules involved in the pluripotent state when compared to their progenitors, primordial germ cells (PGCs), and other pluripotent stem cells. Microarray and Principal Component Analysis (PCA) reveals for the first time that human EGCs possess a transcription profile distinct from PGCs and other pluripotent stem cells. Validation with qRT-PCR confirms that human EGCs and PGCs express many pluripotency-associated genes but with quantifiable differences compared to pluripotent embryonic stem cells (ESCs), induced pluripotent stem cells (IPSCs), and embryonal carcinoma cells (ECCs). Analyses also identified a number of target genes that may be potentially associated with their unique pluripotent states. These include IPO7, MED7, RBM26, HSPD1, and KRAS which were upregulated in EGCs along with other pluripotent stem cells when compared to PGCs. Other potential target genes were also found which may contribute toward a primed ESC-like state. These genes were exclusively up-regulated in ESCs, IPSCs and ECCs including PARP1, CCNE1, CDK6, AURKA, MAD2L1, CCNG1, and CCNB1 which are involved in cell cycle regulation, cellular metabolism and DNA repair and replication. Gene classification analysis also confirmed that the distinguishing feature of EGCs compared to ESCs, ECCs, and IPSCs lies primarily in their genetic contribution to cellular metabolism, cell cycle, and cell adhesion. In contrast, several genes were found upregulated in PGCs which may help distinguish their unipotent state including HBA1, DMRT1, SPANXA1, and EHD2. Together, these findings provide the first glimpse into a unique genomic signature of human germ cells and pluripotent stem cells and provide genes potentially involved in defining different states of germ-line pluripotency
- …
