181.
Initial studies of SCI LAN topologies for local area clustering
- Haakon Bryhni
A Local Area Network (LAN) can be built using the
ANSI/IEEE Standard 1592-1992 Scalable Coherent Interface
(SCI) as the underlying hardware protocol. For the LAN, SCI
will act as a new physical layer, and traditional protocols (as
e.g. TCP/IP) may be run on top of SCI. In a first approach, SCI
is used to implement message passing while new protocols and
functions that take advantage of the shared memory functionality
can be developed. In this paper we do initial studies of
throughput and latency at the physical layer for some SCI
LAN candidate topologies. This performance will be a hard
upper bound for application performance. SCI LANs based on
ring, switched...
182.
Chromatic Numbers and Bohr Topologies
We use chromatic numbers of hypergraphs to study the Bohr topology
on discrete abelian groups. In particular, if K is an in
nite
abelian group of a given prime exponent, we show that G
are
homeomorphic i G is the product of K and some
nite group. Also,
if K is of
nite exponent and G is not of
nite exponent, then G
never topologically embeddable in K
.
183.
Distributed Maintenance of Resource Efficient Wireless Network Topologies (Extended Abstract)
- Matthias Grunewald,Tamas Lukovszki,Christian Schindelhauer,Klaus Volbert
Multiple hop routing in mobile ad hoc networks can minimize energy consumption and increase data throughput. Yet, the problem of radio interferences remains. However if the routes are restricted to a basic network based on local neighborhoods, these interferences can be reduced such that standard routing algorithms can be applied. We compare different network topologies...
184.
Topologies for SCI-based systems with up to a few hundred nodes
- Bothner Johnweding,Hulaas Trondivar
In this paper we wish to show some of the possible ways in which small SCI-rings can be connected together to form large systems of switches, processors and memories. Choosing a topology is very much dependent of the use of the network. A general multiprocessor requires an entirely different system than for example a data acquisition system. The topologies mentioned in this paper are relevant to general multiprocessors. The authors are currently implementing a simulation model for some of these topologies as part of their thesis.
185.
Topologies, Continuity And Bisimulations
- J. M. Davoren
. The notion of a bisimulation relation is of basic importance
in many areas of computation theory and logic. Of late, it has come
to take a particular significance in work on the formal analysis and
verification of hybrid control systems, where system properties are expressible
by formulas of the modal -calculus or weaker temporal logics.
Our purpose here is to give an analysis of the concept of bisimulation,
starting with the observation that the zig-zag conditions are suggestive
of some form of continuity. We give a topological characterization of
bisimularity for preorders, and then use the topology as a route to examining
the algebraic semantics for the -calculus,...
186.
Topologies, Continuity And Bisimulations
- J. M. Davoren
. The notion of a bisimulation relation is of basic importance
in many areas of computation theory and logic. Of late, it has
come to take a particular significance in work on the formal analysis
and verification of hybrid control systems, where system properties
are expressible by formulas of the modal -calculus or weaker temporal
logics. Our purpose here is to give an analysis of the concept
of bisimulation, starting with the observation that the zig-zag conditions
are suggestive of some form of continuity. We give a topological
characterization of bisimularity for preorders, and then use the topology
as a route to examining the algebraic semantics for the -calculus,
developedinrecentworkofKwiatkowskaet...
187.
Interconnection Topologies and Routing
- Gabriele Kotsis
this article no explicit name for the topology was given so I decided to call it F-tree
188.
Optimal Design of Logical Topologies in Wavelength-Routed Optical Networks with Multicast Traffic
- M. Ajmone Marsan
In this paper we discuss the optimal design of logical topologies in
wavelength-routed WDM networks supporting unicast and multicast transfer of IP
datagrams. We first explain the key aspects of the problem, emphasizing the fact
that in IP networks the routing algorithms are an input to the optimization problem,
not an optimization target. We then provide a mixed integer linear programming
formulation of the optimization problem, which however leads to unacceptably high
complexity for networks of non-trivially small size. We then propose both greedy
and metaheuristic approaches for the sub-optimal design of logical topologies with
acceptable complexity. Finally, we derive lower bounds that allow the assessment
of the performance...
189.
Multicast Tree Construction in Network Topologies with Asymmetric Link Loads
- Shridhar B. Shukla,Eric B. Boyer,J. Eric Klinker
This paper addresses the problem of constructing multicast trees with reservation of resources. The
main features of the approach described are that it tolerates asymmetric traffic loads on network links and
algorithmically locates data distribution centers for every multiparticipant interaction. A fast and scalable
algorithm for locating distribution centers based on the network load and a priori knowledge of participant's
locations and resource requirements is given. To explicitly handle cases of disjoint send and receive paths
between two nodes, a protocol to build separate send-trees and receive-trees around the centers located in the
above manner is given. Simulation results on various topologies are presented showing that,...
190.
Blocking in Wavelength Routing Networks, Part II: Mesh Topologies
- Yuhong Zhu,George N. Rouskas,Harry G. Perros
We study a class of circuit switched wavelength routing networks with fixed or alternate
routing and with random wavelength allocation. We present an iterative path decomposition
algorithm to accurately and efficiently evaluate the blocking performance of such networks with
and without wavelength converters. Our iterative algorithm analyzes the original network by decomposing
it into single path sub-systems. These sub-systems are analyzed in isolation by using
our previous algorithms for a single path of a wavelength routing network, and the individual
results are appropriately combined to obtain a solution for the overall network. The path decomposition
approach can naturally capture the correlation of both link loads and link...
191.
Multiresolution Surfaces Having Arbitrary Topologies by a Reverse Doo Subdivision Method
- Faramarz F. Samavati,Nezam Mahdavi-amiri,Richard H. Bartels
We have shown how to construct multiresolution structures for reversing subdivision rules using global least
squares models
7
. As a result, semiorthogonal wavelet systems have also been generated. To construct a multiresolution
surface of an arbitrary topology, however, biorthogonal wavelets are needed. In
1
we introduced local least
squares models for reversing subdivision rules to construct multiresolution curves and tensor product surfaces,
noticing that the resulting wavelets were biorthogonal (under a an induced inner product). Here, we construct
multiresolution surfaces of arbitrary topologies by locally reversing the Doo subdivision scheme. In a Doo subdivision,
a coarse surface is converted into a fine one by the contraction of coarse faces...
192.
Design of Logical Topologies in Wavelength-Routed IP Networks
- M. Ajmone Marsan A. Grosso,E. Leonardi,M. Mellia,A. Nucci
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 know (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...
193.
Otimização em dois níveis da orientação e da topologia de cascas laminadas
- Souza, Carlos Eduardo de
Este trabalho é uma contribuição para o conhecimento de metodologias de projeto de estruturas de material composto, aplicando métodos de otimização estrutural a cascas laminadas e apresentando uma estratégia em dois níveis. No primeiro nível é realizada a minimização da flexibilidade da estrutura, tendo como variável de projeto a orientação de cada lâmina da estrutura. Utiliza-se Programação Linear Seqüencial (SLP) e direção de tensão principal para otimização da orientação. No segundo nível minimiza-se o volume de cada lâmina, usando a flexibilidade total da estrutura como restrição e a densidade relativa como variável de projeto, também através de SLP. Para evitar...
194.
On locally convex topologies in sequence spaces (II).
- Tort Pinilla, Manuel
En el presente volumen se publican solamente los dos últimos capítulos de este artículo. Los tres restantes aparecieron en el número anterior
195.
Search for slepton pair production in Gauge Mediated SUSY breaking topologies in e
A search has been performed for topologies characteristic of slepton pair production in Gauge
Mediated SUSY breaking scenarios using 237 pb -1 of data collected with the ALEPH detector at
centre-of-mass energies between 192 and 202 GeV. No evidence of any signal is observed and a 95%
confidence level lower limit on the stau-right mass is obtained independent of its lifetime.
PRELIMINARY
ALEPH contribution to Winter 2000 conferences.
Contact person: Chris.Booth (Chris.Booth@cern.ch)
1
1 Introduction
This note presents preliminary results of a search for slepton pair production in Gauge Mediated SUSY
breaking theories where a slepton is the NLSP in data samples of 28.9 pb -1 , 79.9 pb -1...
196.
Adaptive Routing of QoS-constrained Media Streams over Scalable Overlay Topologies
- Gerald Fry,Richard West
Current research on Internet-based distributed systems
emphasizes the scalability of overlay topologies for efficient
search and retrieval of data items, as well as routing
amongst peers. However, most existing approaches fail to
address the transport of data across these logical networks
in accordance with quality of service (QoS) constraints.
Consequently, this paper investigates the use of scalable
overlay topologies for routing real-time media streams between
publishers and potentially many thousands of subscribers.
Specifically, we analyze the costs of using kary
n-cubes for QoS-constrained routing. Given a number
of nodes in a distributed system, we calculate the optimal
k-ary n-cube structure for minimizing the average
distance between any pair of nodes. Using this structure,
we...
197.
Formal Topologies on the Set of First-Order Formulae
- Thierry Coquand,Sara Sadocco,Giovanni Sambin,Jan M. Smith
this paper that the question has a simple negative answer. This
raised further natural questions on what can be said about the points of these
two topologies; we give some answers.
The observation that topological models for first-order theories can expressed
in the framework of locales appears, for instance, in Fourman and
Grayson [6], where the analogy between points of a locale and models of a
theory is emphasised; the identification of formal points with Henkin sets, gives
a precise form to this analogy. We replace the use of locales by formal topology,
which can be expressed in a predicative framework such as Martin-Lof's type
theory. Proof-theoretic issues are...
198.
Clustering Wide-Contexts and HMM Topologies for Spontaneous Speech Recognition
- Izhak Shafran,Mari Ostendorf,Je Bilmes,William Byrne
In most speech recognition systems today, all the acoustic variation associated with a phoneme is characterized in terms of the identity of its neighboring phonemes. The neighbors influence only the state observation density of a fixed Hidden Markov Model. Other sources of variation are captured implicitly by using Gaussian mixture models for the state observations. Consequently, these models can be very broad, particularly for casual spontaneous speech. In this thesis, we explore conditioning of phonemes on higher level linguistic structure, specifically syllable- and word-level structure to learn models for phonemes that are more specific to the context, reporting experimental results...
199.
Topologie Virtuelle pour Réseaux Hybrides
- Topologie Virtuelle; Topologie Virtuelle; Rseaux Hybrides; Rseaux Hybrides; Fabrice Theoleyre; Fabrice Theoleyre; Fabrice Valois; Fabrice Valois
Hybrid networks are heterogeneous networks merging wireless nodes, ad hoc nodes and where the interconnection to IP world is an important topic through gateways called AP (access point). Indeed, each node can be contacted and can contact another node in Internet. To reach that, architectures to support mobility management will be study. The solutions inspired by wired networks are not particularly suited to hybrid networks. We propose to use a virtual dynamic infrastructure including both backbone and clusters. A backbone is suited to spare energy, optimize control tra#c di#usion, hierarchize participants, . . . The clusters are intended to create...
200.
Performance of Multihop Communications Using Logical Topologies on Optical Torus Networks
- X. Yuan,R. Melhem,R. Gupta
We consider multihop communications on optical torus
networks with time--division multiplexing where logical
topologies are realized on top of the physical network to improve
the communication performance. The logical topologies
reduce the number of intermediate hops at the cost of
a larger multiplexing degree. On the one hand, the larger
multiplexing degree increases the packet communication
time between hops. On the other hand, reducing the number
of intermediate hops reduces the time spent at intermediate
hops. We study the trade--off between the multiplexing degree
and the number of intermediate hops. Specifically, we
study four logical topologies ranging from the most dense
logical all--to--all connections to the simplest logical torus
topology on top of...
