81.
Topologias m-adicas e aneis de series de potencias
- Rosane Tomi Monroy Ushirobira
Not informed
82.
Bohr Topologies and Partition Theorems for Vector Spaces
- Kenneth Kunen
We prove a Ramsey-style theorem for sequences of vectors in an
infinite-dimensional vector space over a finite field. As an application
of this theorem, we prove that there are countably infinite Abelian
groups whose Bohr topologies are not homeomorphic.
1 Introduction
This paper does two things. First, we prove a partition theorem for sequences
of vectors in a vector space. Second, we apply this theorem to study the Bohr
topologies for these vector spaces.
The partition theorem involves sequences, X = hx s : s 2 [!]
n
i, in some
vector space, V, over a finite field. If Vitself is finite, then Ramsey's Theorem
says that for some infinite A `...
83.
Inverse Automata And Profinite Topologies On A Free Group
- Benjamin Steinberg
This paper gives an elementary, self-contained proof that a finite product of finitely generated subgroups of a free group is closed in the profinite topology. The proof uses inverse automata (immersions) and inverse monoid theory. Generalizations are given to other topologies. In particular, we obtain the new result that for arborescent pseudovarieties, the product of two closed finitely generated subgroups is again closed. An application to monoid theory is given.
84.
Generating Network Topologies That Obey Power Laws
- Christopher R. Palmer,J. Gregory Steffan
Recent studies have shown that Internet graphs and other
network systems follow power-laws. Do artificial network
topologies commonly used in network simulation studies obey
these power-laws? In this paper we show that current topology
generators do not obey all of the power-laws, and we present
two new topology generators that do. Finally, we re-evaluate
a multicast study to demonstrate the impact of power-law
topologies.
1 Introduction
Recent studies have shown that Internet graphs follow
power laws [5]---i.e., certain graph metrics follow the
distribution y / x
ff
. This phenomenon has been observed
in router topology, inter-domain topology [5], and the
world-wide-web [1, 2, 6, 7, 8]. Previous metrics used to
characterize Internet graphs have focussed...
85.
Generating Network Topologies That Obey Power Laws
- Christopher R. Palmer,J. Gregory Steffan
Recent studies have shown that Internet graphs and other network systems follow power-laws. Are these laws obeyed by the artificial network topologies used in network simulations? Does it matter? In this paper we show that current topology generators do not obey all of the power-laws, and we present two new topology generators that do. We also re-evaluate a multicast study to show the impact of using power-law topologies. I. Introduction Recent studies have shown that Internet graphs follow power laws [1]---i.e., certain graph metrics follow the distribution y / x ff . This phenomenon has been observed in router topology,...
86.
An Analysis of Bluetooth Scatternet Topologies
- Rohit Kapoor,M. Y. Medy Sanadidi,Mario Gerla
Bluetooth "scatternets" are targeting wider
geographical area applications in factories, warehouses,
shopping malls and various sensor network applications.
Though some earlier work has looked at scatternet formation
and scheduling issues, less attention has been given to
optimizing scatternet topologies. We consider in this paper
topological design of scatternets, taking into consideration
application traffic requirements. We study appropriate
topologies, and size the network in terms of piconets. We
develop a scatternet queuing model and use it to compare the
delay-throughput characteristics of various topologies. We
find that the best topology is application dependent. The
analytical model is also used to determine the optimal point to
operate a scatternet, i.e., the traffic load that saturates...
87.
¿Qué es la topología?
- Macho Stadler, Marta
La autora del artículo nos lleva a través de los tópicos más clasicos de una parte nueva de las matemáticas, como es la topología. Para leer el artículo se requiere de una sólida formación matemática.
88.
Topologies for the Set of Disjunctive omega-Words
- Ludwig Staiger
An infinite sequence (!-word) is referred to as disjunctive provided
it contains every finite word as infix (factor). As Jrgensen
and Thierrin [JT83] observed the set of disjunctive !-words, D,
has a trivial syntactic monoid but is not accepted by a finite automaton.
In this paper we derive some topological properties of the set
of disjunctive !-words. We introduce two non-standard topologies
on the set of all !-words and show that D fulfills some special
properties with respect to these topologies:
In the first topology -- the so-called topology of forbidden words --
D is the smallest nonempty G -set, and in the second one D is the
set of...
89.
Basics of Network Topologies
tch
# wide switches are not available --- small clusters
21 September 2000 7
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Class 4: Switch Fabric
# hierarchical switching fabric --- higher latency than a single switch
21 September 2000 8
Mathematics Department AHPCC Workshop '2000 Ateneo de Manila University
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Class 5: Channel Bonding
# used in original Beouwulf Project --- switch fabric latency still high
21 September 2000 9
Mathematics Department AHPCC Workshop '2000 Ateneo de Manila University
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Class 6: Flat Neighborhood Network
# single switch latency and asymmetric --- routing is very complex
21 September 2000 10
Mathematics Department AHPCC Workshop '2000 Ateneo de Manila University
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KLAT2 -- Kentucky Linux Athlon Testbed
90.
Interconnection Topologies for Parallel Processing Systems
- Gabriele Kotsis,Bitnet Adau Awiuni
Introduction
The growing demand for more computing power at increasing speed in many scientific
and engineering applications made it necessary to develop advanced computer architectures
based on the concept of parallel processing. In general a parallel computer
system consists of various processing and memory units and other (shared) resources.
A critical issue in design and analysis of parallel systems is the way in which the system
components are connected together, since this interconnection network determines the
performance of the whole system [Bhuy 87]. The network topology, defined as the abstract
representation of the connections in the network [?], is a key factor in determing
a suitable architectural structure. A...
91.
Task Assignment in Cayley Interconnection Topologies
- W. J. Gutjahr,M. Hitz,T. A. Mueck
Based on the Cayley graph framework for the generation
and application independent evaluation of multiprocessor interconnection
topologies, an application dependent task mapping
problem is addressed. In particular, we start from an interconnection
topology considered attractive from a graph theoretical
point of view which is produced by an applicationindependent
Cayley graph approach. Given such a graph
together with an application dependent task communication
profile, the problem addressed in this paper is to find an
optimal task-to-processor assignment. Such a mapping yields for
the given graph and the given profile a minimal expected
communication path length and therefore a minimal number
of data transfer steps between the physical processing
elements of a multiprocessor machine.
At first,...
92.
Designing Distance-Preserving Fault-Tolerant Topologies
- Swamy K. Sitarama,Abdol-hossein Esfahanian
In this paper, we consider designing "optimal" fault-tolerant topologies that preserve
distance between every pair of nonadjacent nodes in presence of edge failures. A graph G
is said to preserve distance with respect to a spanning subgraph D, if there exists a path
in G of length at most dD (u; v) joining every nonadjacent vertices u; v of D. We study
two models each with a different optimality criterion. In the first model, minimizing
the overall redundancy is considered. The second model considers regular fault-tolerant
topologies with minimum regularity. Preserving distance is particularly applicable in
communication networks where distance between communicating processors is critical.
Keywords: Fault-tolerance; Distance;...
93.
Scalable Sparse Topologies with Small Spectrum
- R. Elsasser,R. Kralovic,B. Monien
. One of the fundamental properties of a graph is the number of distinct
eigenvalues of its adjacency or Laplacian matrix. Determining this number is of
theoretical interest and also of practical impact. Graphs with small spectra exhibit
many symmetry properties and are well suited as interconnection topologies. Especially
load balancing can be done on such interconnection topologies in a small
number of steps. In this paper we are interested in graphs with maximal degree
O(log n), where n is the number of vertices, and with a small number of distinct
eigenvalues. Our goal is to find scalable families of such graphs with polylogarithmic
spectrum in the number...
94.
Power Efficient Topologies for Wireless Sensor Networks
- Ayad Salhieh,Loren Schwiebert
ering
self-organization of the sensor nodes into a network, we address efficient placement of fixed nodes.
Some of these networks that can be installed in a building to monitor the building or in an assembly. Where the use of
regular topology will have better advantage than mobile. In a fixed topology we can place the nodes so they can give better
coverage . Also the use of regular topology or mesh topologies, a node also function as a router and can relay messages for
its neighbors. Those networks offers multiple redundant communications paths throughout the network. If one node die or fail
other nodes can be...
95.
Forming Connected Topologies in Bluetooth Adhoc Networks
- R. Guerin,J. Rank,S. Sarkar,E. Vergetis
This paper explores the problem of forming
connected topologies, in adhoc networks built on the Bluetooth
technology. Providing connectivity, when feasible, is
the most basic requirement for any system aimed at allowing
devices to communicate with each other. In this paper,
we illustrate that this seemingly innocuous goal gives rise to
many significant challenges in the context of the Bluetooth
technology. The paper first provides a brief overview of
Bluetooth and its operation, and then identifies some of the
major problems the technology faces when it is used to build
adhoc networks. The paper's contributions are in identifying
some basic algorithmic problems when building connected
Bluetooth networks, and in developing and evaluating
several...
96.
On Efficient Topologies for Bluetooth Scatternets
- Daniele Mior,Arianna Trainito,Andrea Zanella
In this paper we investigate the relationship between network capacity
and topology for Bluetooth scatternets. We start by considering the intrinsic
capacity limits of a scatternet structure, and we show that limiting capacity may
be achieved for very local traffic and under specific conditions on the scatternet
structure. Then, we provide a description of the performance achievable with
two basic scatternet configurations, namely star and closed--loop topologies, and
show the role played by inter--piconet interference in the choice of efficient configurations.
97.
Topologies, Migration Rates, and Multi-Population Parallel Genetic Algorithms
This paper presents an analysis of parallel genetic algorithms (GAs) with multiple populations
(demes). The analysis makes explicit the relation between the probability of reaching a
desired solution with the deme size, the migration rate, and the degree of the connectivity graph.
The analysis considers arbitrary topologies with a fixed number of neighbors per deme. The
demes evolve in isolation until each converges to a unique solution. Then, the demes exchange
an arbitrary number of individuals and restart their execution. An accurate deme-sizing equation
is derived, and it is used to determine the optimal configuration of an arbitrary number of
demes that minimizes the execution time of...
98.
Topologies, Migration Rates, and Multi-Population Parallel Genetic Algorithms
This paper presents an analysis of parallel genetic algorithms (GAs) with multiple populations
(demes). The analysis makes explicit the relation between the probability of reaching a
desired solution with the deme size, the migration rate, and the degree of the connectivity graph.
The analysis considers arbitrary topologies with a fixed number of neighbors per deme. The
demes evolve in isolation until each converges to a unique solution. Then, the demes exchange
an arbitrary number of individuals and restart their execution. An accurate deme-sizing equation
is derived, and it is used to determine the optimal configuration of an arbitrary number of
demes that minimizes the execution time of...
99.
Design of Logical Topologies in Wavelength-Routed IP Networks
In this paper we discuss the optimal design of logical topologies in wavelength-routed IP over WDM networks supporting both
unicast and multicast transfer of IP datagrams under deterministic and stochastic traffic patterns. The paper brings mainly three
original contributions: i) it provides a MILP formalization of the optimal Logical Topology Design (LTD) problem in presence
of multicast traffic under a perfectly known (deterministic) traffic pattern and proposes sub-optimal greedy and metaheuristic
algorithms for its solution; ii) it derives novel, tight optimistic bounds that allow the assessment of the performance of the proposed
algorithms; iii) it investigates the optimal logical topology design problem, when traffic patterns...
100.
Network Topologies for Scalable Multi-User Virtual Environments
- Thomas A. Funkhouser
This paper investigates trade-offs of different network
topologies and messaging protocols for multi-uservirtual
environment systems. We present message distribution
techniques appropriate for constructing scalable
multi-user systems for a variety of network characteristics.
Hierarchical system designs utilizing servers
that manage message distribution for entities in separate
regions of a virtual environment are described that
scale to arbitrary numbers of simultaneous users. Experimental
results show that the rate of messages processed
by server workstations in this system design are
less than using previously described approaches.
1. Introduction
With the recent increases in network bandwidth
and graphics performance in desktop computers, there
is a growing interest in distributed visual simulation
systems that allow multiple users to interact in a
shared...
