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89
The synchronization of periodic routing messages
 IEEE/ACM Transactions on Networking
, 1994
"... Abstract — The paper considers a network with many apparentlyindependent periodic processes and discusses one method by which these processes can inadvertent Iy become synchronized. In particular, we study the synchronization of periodic routing messages, and offer guidelines on how to avoid inadve ..."
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Cited by 281 (11 self)
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Abstract — The paper considers a network with many apparentlyindependent periodic processes and discusses one method by which these processes can inadvertent Iy become synchronized. In particular, we study the synchronization of periodic routing messages, and offer guidelines on how to avoid inadvertent synchronization. Using simulations and analysis, we study the process of synchronization and show that the transition from unsynchronized to synchronized traffic is not one of gradual degradation but is instead a very abrupt ‘phase transition’: in general, the addition of a single router will convert a completely unsynchronized traffic stream into a completely synchronized one. We show that synchronization can be avoided by the addition of randomization to the tra~c sources and quantify how much randomization is necessary. In addition, we argue that the inadvertent synchronization of periodic processes is likely to become an increasing problem in computer networks.
An Implementation of Interprocedural Bounded Regular Section Analysis
 IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS
, 1991
"... Optimizing compilers should produce efficient code even in the presence of highlevel language constructs. However, current programming support systems are significantly lacking in their ability to analyze procedure calls. This deficiency complicates parallel programming, because loops with calls ca ..."
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Cited by 221 (27 self)
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Optimizing compilers should produce efficient code even in the presence of highlevel language constructs. However, current programming support systems are significantly lacking in their ability to analyze procedure calls. This deficiency complicates parallel programming, because loops with calls can be a significant source of parallelism. We describe an implementation of regular section analysis, which summarizes interprocedural side effects on subarrays in a form useful to dependence analysis while avoiding the complexity of prior solutions. The paper gives the results of experiments on the Linpack library and a small set of scientific codes.
Adaptive Software Cache Management for Distributed Shared Memory Architectures
 In Proceedings of the 17th Annual International Symposium on Computer Architecture
, 1990
"... An adaptive cache coherence mechanism exploits semantic information about the expected or observed access behavior of particular data objects. We contend that, in distributed shared memory systems, adaptive cache coherence mechanisms will outperform static cache coherence mechanisms. We have examine ..."
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Cited by 128 (15 self)
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An adaptive cache coherence mechanism exploits semantic information about the expected or observed access behavior of particular data objects. We contend that, in distributed shared memory systems, adaptive cache coherence mechanisms will outperform static cache coherence mechanisms. We have examined the sharing and synchronization behavior of a variety of shared memory parallel programs. We have found that the access patterns of a large percentage of shared data objects fall in a small number of categories for which efficient software coherence mechanisms exist. In addition, we have performed a simulation study that provides two examples of how an adaptive caching mechanism can take advantage of semantic information. 1 Introduction We are developing Munin [4], a system that will allow programs written for shared memorymultiprocessors to be executed efficiently on distributed memory machines. What distinguishes Munin from previous distributed shared memory systems [6, 12, 14] is the ...
Interprocedural Symbolic Analysis
, 1994
"... Compiling for efficient execution on advanced computer architectures requires extensive program analysis and transformation. Most compilers limit their analysis to simple phenomena within single procedures, limiting effective optimization of modular codes and making the programmer's job harder. ..."
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Cited by 48 (1 self)
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Compiling for efficient execution on advanced computer architectures requires extensive program analysis and transformation. Most compilers limit their analysis to simple phenomena within single procedures, limiting effective optimization of modular codes and making the programmer's job harder. We present methods for analyzing array side effects and for comparing nonconstant values computed in the same and different procedures. Regular sections, described by rectangular bounds and stride, prove as effective in describing array side effects in Linpack as more complicated summary techniques. On a set of six programs, regular section analysis of array side effects gives 0 to 39 percent reductions in array dependences at call sites, with 10 to 25 percent increases in analysis time. Symbolic analysis is essential to data dependence testing, array section analysis, and other highlevel program manipulations. We give methods for building symb...
Automatic Data Layout for Distributed Memory Machines
, 1995
"... The goal of languages like Fortran D or High Performance Fortran (HPF) is to provide a simple yet efficient machineindependent parallel programming model. Besides the algorithm selection, the data layout choice is the key intellectual challenge in writing an efficient program in such languages. The ..."
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Cited by 35 (5 self)
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The goal of languages like Fortran D or High Performance Fortran (HPF) is to provide a simple yet efficient machineindependent parallel programming model. Besides the algorithm selection, the data layout choice is the key intellectual challenge in writing an efficient program in such languages. The performance of a data layout depends on the target compilation system, the target machine, the problem size, and the number of available processors. This makes the choice of a good layout extremely difficult for most users of such languages. This thesis discusses the design and implementation of a data layout selection tool that generates Fortran D or HPF style data layout specifications automatically. Because the tool is not embedded in the target compiler and will be run only a few times during the tuning phase of an application, it can use techniques that may be considered too computationally expensive for inclusion in today's compilers. The proposed framework for automatic data layout s...
Equivariant constrained symplectic integration
 J. Nonlinear Sci
, 1995
"... We use recent results on symplectic integration of Hamiltonian systems with constraints to construct symplectic integrators on cotangent bundles of manifolds by embedding the manifold in a linear space. We also prove that these methods are equivariant under cotangent lifts of a symmetry group acting ..."
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Cited by 27 (3 self)
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We use recent results on symplectic integration of Hamiltonian systems with constraints to construct symplectic integrators on cotangent bundles of manifolds by embedding the manifold in a linear space. We also prove that these methods are equivariant under cotangent lifts of a symmetry group acting linearly on the ambient space and consequently preserve the corresponding momentum. These results provide an elementary construction of symplectic integrators for LiePoisson systems and other Hamiltonian systems with symmetry. The methods are illustrated on the free rigid body, the heavy top, and the double spherical pendulum. 1.
GALOIS GROUPS OF SCHUBERT PROBLEMS Via Homotopy Computation
, 2009
"... Numerical homotopy continuation of solutions to polynomial equations is the foundation for numerical algebraic geometry, whose development has been driven by applications of mathematics. We use numerical homotopy continuation to investigate the problem in pure mathematics of determining Galois grou ..."
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Cited by 22 (18 self)
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Numerical homotopy continuation of solutions to polynomial equations is the foundation for numerical algebraic geometry, whose development has been driven by applications of mathematics. We use numerical homotopy continuation to investigate the problem in pure mathematics of determining Galois groups in the Schubert calculus. For example, we show by direct computation that the Galois group of the Schubert problem of 3planes in C 8 meeting 15 fixed 5planes nontrivially is the full symmetric group S6006.
A covolume method based on rotated bilinears for the generalized Stokes problem
 SIAM J Numer Anal
, 1998
"... This Article is brought to you for free and open access by the Mathematics and Statistics at ScholarWorks@BGSU. It has been accepted for inclusion in Mathematics and Statistics Faculty Publications by an authorized administrator of ScholarWorks@BGSU. ..."
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Cited by 16 (7 self)
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This Article is brought to you for free and open access by the Mathematics and Statistics at ScholarWorks@BGSU. It has been accepted for inclusion in Mathematics and Statistics Faculty Publications by an authorized administrator of ScholarWorks@BGSU.