57,874 research outputs found
Instant topological relationships hidden in the reality
In most applications of general topology, topology usually is not the first,
primary structure, but the information which finally leads to the construction of
the certain, for some purpose required topology, is filtered by more or less
thick filter of the other mathematical structures. This fact has two main
consequences:
(1) Most important applied constructions may be done in the primary
structure, bypassing the topology.
(2) Some topologically important information from the reality may be lost
(filtered out by the other, front-end mathematical structures).
Thus some natural and direct connection between topology and the reality
could be useful. In this contribution we will discuss a pointless topological
structure which directly reflects relationship between various locations which
are glued together by possible presence of a physical object or a virtual
``observer"
Robustness and Reliability for Virtual Topologies in Wireless Multihop Access Networks
International audienceMobile ad hoc networks (MANet) are a spontaneous collection of mobile terminals. Each node must collaborate in order to structure information exchange. An hybrid network is a MANet connected to Internet via an Access Point (AP). We propose to organize MANet and hybrid networks through a virtual topology. We consider a virtual topology as a hierarchical organization based on the integration of both backbone and clusters. Construction and maintenance procedures of such a virtual topology are detailed and deal with robustness and reliability issues. We present a proactive gratuitous maintenance for our backbone and a new maintenance algorithm for clusters presenting a reduced overhead. Moreover, this improved solution allows to integrate multiple APs in hybrid networks , deleting the previous single point of failure. A method to interconnect backbones is described, which is useful for many applications
Representability of algebraic topology for biomolecules in machine learning based scoring and virtual screening
This work introduces a number of algebraic topology approaches, such as
multicomponent persistent homology, multi-level persistent homology and
electrostatic persistence for the representation, characterization, and
description of small molecules and biomolecular complexes. Multicomponent
persistent homology retains critical chemical and biological information during
the topological simplification of biomolecular geometric complexity.
Multi-level persistent homology enables a tailored topological description of
inter- and/or intra-molecular interactions of interest. Electrostatic
persistence incorporates partial charge information into topological
invariants. These topological methods are paired with Wasserstein distance to
characterize similarities between molecules and are further integrated with a
variety of machine learning algorithms, including k-nearest neighbors, ensemble
of trees, and deep convolutional neural networks, to manifest their descriptive
and predictive powers for chemical and biological problems. Extensive numerical
experiments involving more than 4,000 protein-ligand complexes from the PDBBind
database and near 100,000 ligands and decoys in the DUD database are performed
to test respectively the scoring power and the virtual screening power of the
proposed topological approaches. It is demonstrated that the present approaches
outperform the modern machine learning based methods in protein-ligand binding
affinity predictions and ligand-decoy discrimination
Unsolved Problems in Virtual Knot Theory and Combinatorial Knot Theory
This paper is a concise introduction to virtual knot theory, coupled with a
list of research problems in this field.Comment: 65 pages, 24 figures. arXiv admin note: text overlap with
arXiv:math/040542
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Dynamic virtual private network provisioning from multiple cloud infrastructure service providers
The Cloud infrastructure service providers currently provision basic virtualized computing resources as on demand and dynamic services but there is no common framework in existence that allows the seamless provisioning of even these basic services across multiple cloud service providers, although this is not due to any inherent incompatibility or proprietary nature of the foundation technologies on which these cloud platforms are built. We present a solution idea which aims to provide a dynamic and service oriented provisioning of secure virtual private networks on top of multiple cloud infrastructure service providers. This solution leverages the benefits of peer to peer overlay networks, i.e., the flexibility and scalability to handle the churn of nodes joining and leaving the VPNs and can adapt the topology of the VPN as per the requirements of the applications utilizing its intercloud secure communication framework
Polyfolds: A First and Second Look
Polyfold theory was developed by Hofer-Wysocki-Zehnder by finding
commonalities in the analytic framework for a variety of geometric elliptic
PDEs, in particular moduli spaces of pseudoholomorphic curves. It aims to
systematically address the common difficulties of compactification and
transversality with a new notion of smoothness on Banach spaces, new local
models for differential geometry, and a nonlinear Fredholm theory in the new
context. We shine meta-mathematical light on the bigger picture and core ideas
of this theory. In addition, we compiled and condensed the core definitions and
theorems of polyfold theory into a streamlined exposition, and outline their
application at the example of Morse theory.Comment: 62 pages, 2 figures. Example 2.1.3 has been modified. Final version,
to appear in the EMS Surv. Math. Sc
Virtual Knot Theory --Unsolved Problems
This paper is an introduction to the theory of virtual knots and links and it
gives a list of unsolved problems in this subject.Comment: 33 pages, 7 figures, LaTeX documen
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