121.
Mesh Routing Topologies For Multi-FPGA Systems
- Scott Hauck,Gaetano Borriello,Carl Ebeling
There is currently great interest in using fixed arrays of
FPGAs for logic emulators, custom computing devices,
and software accelerators. An important part of designing
such a system is determining the proper routing topology
to use to interconnect the FPGAs. This topology can
have a great effect on the area and delay of the resulting
system. Tree, Bipartite Graph, and Mesh interconnection
schemes have all been proposed for use in FPGA-based
systems. In this paper we examine Mesh interconnection
schemes, and propose several constructs for more efficient
topologies. These reduce inter-chip delays by more than
60% over the basic 4-way Mesh.
Introduction
In the time since they were introduced, FPGAs have
moved from being...
122.
Power Efficient Topologies for Wireless Sensor Networks
- Ayad Salhieh,Jennifer Weinmann,Manish Kochhal,Loren Schwiebert
Wireless sensor networks have become possible because
of the on-going improvements in sensor technology and
VLSI. One issue in smart sensor networks is achieving efficient
operation because of the limited available power.
For important classes of sensor networks, such as biomedical
sensors, the locations of the sensing nodes are fixed
and the placement can be pre-determined. In this paper,
we consider the topology that best supports communication
among these sensor nodes. We propose a power-aware routing
protocol and simulate the performance, showing that
our routing protocol adapts routes to the available power.
This leads to a reduction in the total power used as well as
more even power usage across nodes. We...
123.
Merging Logical Topologies Using End-to-end
- Mark Coates,Michael Rabbat,Robert Nowak
Knowledge of network topology is useful for understanding
the structure of the Internet, for developing and testing new
protocols, and as prior information to network tomography
algorithms. Building on existing techniques for inferring a
single-source tree topology using end-to-end measurements,
we address the problem of merging multiple tree topologies.
We develop a multiple source active probing methodology
and statistical framework for testing whether the paths from
two sources to two receivers branch at a common internal
node. This information can then be used to determine where
portions of the tree topology from one source to a set of receivers
overlap with the tree topology from a di#erent source
to the same set...
124.
Fundamentos de topología algebraica : un enfoque / Alberto Rafael Mejías Espinoza
- Mejías Espinoza, Alberto Rafael; Universidad de Los Andes. Núcleo Universitario del Táchira, Trabajo de ascenso, 1988
Mecanografiado
125.
Dislocated Topologies
- Pascal Hitzler,Anthony Karel Seda
this
paper are motivated by such considerations.
126.
Designing Distance-Preserving Fault-Tolerant Topologies
- Swamy K. Sitarama,Abdol-hossein Esfahanian
. In this paper we introduce and study a new family of graphs
called distance preserving graphs. A graph G is said to be k-edge distance
preserving with respect to a spanning subgraph D, if there exist
k edge-disjoint u-v paths in G of length at most dD (u; v) for every pair
of nonadjacent vertices u; v of D. We study two design 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. The focus of this paper
is on designs based on model 2. In particular, we construct distance
preserving...
127.
New Topologies for Parallel Systems With Optical Interconnections
- A. Ferreira,K. Marcus
At the present, most of the proposed architectures for interconnecting nodes in
processor networks are based on graph topologies. Very recently, renewed interest has
been shown for bus-based topologies, where (electronic/optical) buses span several processors,
implementing one-to-many communications. In this paper we study topologies
based on the hypergraph theory, taking advantage of the wavelength division muliplexing
(WDM) that allows the huge bandwidth of optical fiber to be divided into several
high-speed logical channels. We show that our topologies compare very well against
graph-based ones, in terms of maximum hop distance, fault tolerance and number of
transceivers per node (constant).
1 Introduction
Most of the proposed architectures for processor interconnection networks...
128.
Building Efficient Bluetooth Scatternet Topologies from 1-Factors
- Simon Baatz,Christoph Bieschke,Matthias Frank,Peter Martini,Christoph Scholz,Carmen K Uhl
Bluetooth introduces ad hoc connectivity into the personal area. Although only the basic single-hop star-shaped topology called piconet is currently available, Bluetooth will surely evolve towards multi-hop connectivity in the near future. These multi-hop networks (called scatternets) offer a wide range of possible topologies. In this paper it is argued that the overall efficiency of scatternets heavily depends on the specific network topology employed. Furthermore, we introduce a class of network topologies that are efficient with respect to the aggregate bandwidth possible. A distributed algorithm for automatic network establishment is outlined.
129.
Sensor and Network Topologies of Formations
- Tolga Eren,Walter Whiteley,A. Stephen Morse,Peter N. Belhumeur,Brian D. O. Anderson
Sensor and network topologies of formations of
autonomous agents are considered. The aim of the paper is to
suggest an approach for such topologies for formations with
direction, bearing and angle information between agents in the
plane and in 3-space. A number of results are translated from
prior work in this field and in the study of constraints in CAD
programming, in rigidity theory, in structural engineering and
in discrete mathematics. Some new results are presented both
for the plane and for 3-space. A number of unsolved problems
are also mentioned.
130.
Topologies for Optical Interconnection Networks Based on OTIS
- David Coudert,Afonso Ferreira,Xavier Muoz
Many results exist in the literature describing technological and theoretical advances in optical network topologies and design. However, an essential effort has yet to be done in linking those results together. In this paper, we propose a step in this direction, by giving optical layouts for several graph-theoretical topologies studied in the literature, using the Optical Transpose Interconnection System (OTIS) architecture. These topologies include the family of Partitioned Optical Passive Star (POPS) and stack-Kautz networks as well as a generalization of the Kautz and de Bruijn digraphs.
131.
Genetic Algorithms for Designing Multihop Lightwave Network Topologies
- C. Gazen,C. Ersoy
Multihop lightwave networks are a means of utilizing the large bandwidth of optical fibers. In these networks, each node has a fixed
number of transmitters and receivers connected to a common optical medium. A multihop topology is implemented logically by assigning
different wavelengths to pairs of transmitters and receivers. By using tunable lasers or receivers, it is possible to modify the topology
dynamically when node failures occur or traffic loads change. The reconfigurability of logical multihop lightwave networks requires that
optimal topologies and flow assignments be found. In this article, optimization of these logical topologies by genetic algorithms is
investigated. The genetic algorithm takes topologies...
132.
On the Origin of Power Laws in Internet Topologies
- Alberto Medina,Ibrahim Matta,John Byers
Recent empirical studies [6] have shown that Internet topologies
exhibit power laws of the form y = x
for the following relationships:
(P1) outdegree of node (domain or router) versus rank;
(P2) number of nodes versus outdegree; (P3) number of node pairs
within a neighborhood versus neighborhood size (in hops); and
(P4) eigenvalues of the adjacency matrix versus rank. However,
causes for the appearance of such power laws have not been convincingly
given. In this paper, we examine four factors in the formation
of Internet topologies. These factors are (F1) preferential
connectivity of a new node to existing nodes; (F2) incremental
growth of the network; (F3) distribution of nodes in space;...
133.
On the Origin of Power Laws in Internet Topologies
- Alberto Medina,Ibrahim Matta,John Byers
Recent empirical studies [6] have shown that Internet topologies
exhibit power laws of the form y = x
for the following relationships:
(P1) outdegree of node (domain or router) versus rank;
(P2) number of nodes versus outdegree; (P3) number of node pairs
within a neighborhood versus neighborhood size (in hops); and
(P4) eigenvalues of the adjacency matrix versus rank. However,
causes for the appearance of such power laws have not been convincingly
given. In this paper, we examine four factors in the formation
of Internet topologies. These factors are (F1) preferential
connectivity of a new node to existing nodes; (F2) incremental
growth of the network; (F3) distribution of nodes in space;...
134.
Two Topologies of the Granular Evidence-Based Adaptive
- Alexander Valishevsky,Arkady Borisov
In this paper two different topologies of the granular evidence-based adaptive network ANGIE
(Adaptive Network for Granular Information and Evidence processing) are considered. The output of the
network based on one of the topologies is more precise, while the output of the network based on alternative
architecture is less precise, at the same time the latter requires less computational power. The possibility of using
ANGIE adaptive network in solving sensitivity analysis tasks is considered as well.
135.
Optical Tree Topologies: Access Control and Wavelength Assignment
- Mario Gerla,Joseph Bannister
Fiber optic tree topologies are emerging as attractive candidates for Passive Optical Network
(PON) implementations, next to the more traditional star and bus topologies. In this paper, we
first address the "physical" properties of the optical tree topology (like layout cost, geographical
coverage, power budget and fault tolerance) and compare them to similar properties in buses
and stars. Then, we discuss the access schemes which can be implemented on a tree. We discuss
the introduction of Wavelength Division Multiplexing (WDM) in the PON and describe singlehop
and multi-hop "virtual" topologies which can be supported. Finally, we present MONET, a
Multilevel Optical Network architecture which can be efficiently...
136.
Optical Tree Topologies: Access Control and Wavelength Assignment
- Mario Gerla,Joseph Bannister
Fiber optic tree topologies are emerging as attractive candidates for Passive Optical Network
(PON) implementations, next to the more traditional star and bus topologies. In this paper, we
first address the "physical" properties of the optical tree topology (like layout cost, geographical
coverage, power budget and fault tolerance) and compare them to similar properties in buses
and stars. Then, we discuss the access schemes which can be implemented on a tree. We discuss
the introduction of Wavelength Division Multiplexing (WDM) in the PON and describe singlehop
and multi-hop "virtual" topologies which can be supported. Finally, we present MONET, a
Multilevel Optical Network architecture which can be efficiently...
137.
On the Origin of Power Laws in Internet Topologies
- Alberto Medina,Ibrahim Matta,John Byers
Recent empirical studies [7] have shown that Internet topologies exhibit power laws of the
form y = x
for the following relationships: (P1) outdegree of node (domain or router) versus
rank; (P2) number of nodes versus outdegree; (P3) number of node pairs within a neighborhood
versus neighborhood size (in hops); and (P4) eigenvalues of the adjacency matrix versus rank.
However, causes for the appearance of such power laws have not been convincingly given. In
this paper, we examine four factors in the formation of Internet topologies. These factors are
(F1) preferential connectivity of a new node to existing nodes; (F2) incremental growth of
the network; (F3) distribution of...
138.
Modelling IP Network Topologies by Emulating Network Development Processes
- Jason Spencer,Lionel Sacks
Recent developments in Internet mapping and
metrification as well as research into scale-free networks has
given us an insight into modelling inter-connected IP networks.
A number of topology generators have emerged which attempt
to generate topologies which follow the power laws discovered in
Internet topologies but don't consider the causes of the power
laws. They tend to concentrate on creating a topology that
follows the power laws on a macroscopic scale. In this paper we
present a generalisation of a topology generator which emulates
microscopic network growth decisions to generate macro-scale
topologies which may follow power-laws. The microscopic
decisions are examined further and their effect on the
macroscopic result demonstrated. The design...
139.
Estimating HMM Topologies
- Thorsten Brants
There are several ways of estimating parameters for HMMs when used for natural
language models. One can use word-n-grams and n-grams of automatically derived
categories for speech recognition. Or one can use part-of-speech n-grams for part-ofspeech
tagging, either by using a manually tagged corpus or by using the Baum-Welch
algorithm. This paper shows how to use another method for parameter estimation:
Model Merging. It exploits the advantages of the other methods, is applicable both
for speech recognition and part-of-speech tagging and, unlike other techniques, it not
only induces transition and output probabilities but also the model topology, i.e. the
number of states and their respective possible outputs. Thus...
140.
On the Origin of Power Laws in Internet Topologies
- Alberto Medina,Ibrahim Matta,John Byers
Recent empirical studies [7] have shown that Internet topologies exhibit power laws of the
form y = x
for the following relationships: (P1) outdegree of node (domain or router) versus
rank; (P2) number of nodes versus outdegree; (P3) number of node pairs within a neighborhood
versus neighborhood size (in hops); and (P4) eigenvalues of the adjacency matrix versus rank.
