ppxscal/embedding_network huggingface dataset:
Directional Gossip: Gossip in a Wide Area Network
Authors: Meng Lin, Keith Marzullo
Venue:  (1999)

We study the problem of reliable dissemination information in a wide area network. Traditional reliable broadcast protocols provide high reliability but do not scale well. Gossip-based protocols appear to be a viable approach. They have been developed to address scalability while still providing high reliability of message delivery. However, gossip protocols either ignore the topology of the wide-area network and thus incur a large load on some network elements or can suffer from a low reliability because they do not take the connectivity of the wide-area network into account. We present a new gossip protocol, called {\em directional gossip}, that uses flooding when necessary to attain good reliability and that uses gossip when flooding (and hence its inherent high overhead) is not needed. The determination of when to use flooding or gossip is done dynamically.
Isotach Networks
Authors: Paul F. Reynolds,  Jr., Craig Williams, Raymond R. Wagner,  Jr.
Venue:  (1995)

We introduce a class of networks called isotach networks designed to reduce the cost of concurrency control in asynchronous computations. Isotach networks support several properties important to the correct execution of parallel and distributed computations: atomicity, causal message delivery, sequential consistency, and memory coherence in systems in which shared data can replicate and migrate. They allow processes to execute atomic actions without locks and to pipeline memory accesses without sacrificing sequential consistency. Isotach networks can be implemented in a wide variety of configurations, including NUMA (non-uniform memory access) multiprocessors and distributed as well as parallel systems. Networks that implement isotach time systems are characterized not by their topology, but by the guarantees they make about the relative order in which messages appear to be delivered. These guarantees are expressed in logical time, not physical time. Physical time guarantees would be prohibitively expensive, whereas logical time guarantees can be enforced cheaply, using purely local knowledge, and yet are powerful enough to support efficient techniques for coordinating asynchronously executing processes. Empirical and analytic studies of isotach systems show that they outperform conventional systems under realistic workloads, in some cases by an order of magnitude or more.
Metrics for Evaluating Database Selection Techniques
Authors: James C. French, Allison L. Powell
Venue:  (1999)

The increasing availability of online databases and other information resources in digital libraries has created the need for efficient and effective algorithms for selecting databases to search. A number of techniques have been proposed for query routing or database selection. We have developed a methodology and metrics that can be used to directly compare competing techniques. They can also be used to isolate factors that influence the performance of these techniques so that we can better understand performance issues. In this paper we describe the methodology we have used to examine the performance of database selection algorithms such as gGlOSS and CORI. In addition we develop the theory behind a ``random'''' database selection algorithm and show how it can be used to help analyze the behavior of realistic database selection algorithms.
Assaulting the Tower of Babel: Experiences with a Translator Writing System
Authors: Harvey Abramson, W. F. Appelbe, M. S. Johnson
Venue:  (1977)

TRUST is a translator writing system (TWS) which evolved from several available TWS components, including an LR (k) parser generator and a lexical scanner generator. The design and historical development of TRUST are briefly presented, but the paper is primarily concerned with relating critically the experiences gained in applying the TWS to various practical software projects and to the classroom environment. These experiences lead to a discussion of how a modular TWS should be designed and implemented.
A Model-Based Vision System for Manipulator Position Sensing
Authors: I. J Mulligan, Alan K. Mackworth, Lawrence
Venue:  (1989)

The task and design requirements for a vision system for manipulator position sensing in a telerobotic system are described. Model-based analysis-by-synthesis techniques offer generally applicable methods with the potential to meet the system''s requirement for accurate, fast and reliable results. Edge-based chamfer matching allows efficient computation of a measure, E, of the local difference between the real image and a synthetic image generated from arm and camera models. Gradient descent techniques are used to minimize E by adjusting joint angles. The dependence of each link position on the position of the link preceding it allows the search to be broken down into lower dimensional problems. Intensive exploitation of geometric constraints on the possible position and orientation of manipulator components results in a correct and efficient solution to the problem. Experimental results demonstrate the use of the implemented prototype system to locate the boom, stick and bucket of an excavator, given a single video image.
Learning Fixed-Dimension Linear Thresholds from Fragmented Data
Authors: Paul W. Goldberg
Venue:  (1999)

We investigate PAC-learning in a situation in which examples (consisting of an input vector and 0/1 label) have some of the components of the input vector concealed from the learner. This is a special case of Restricted Focus of Attention (RFA) learning. Our interest here is in 1-RFA learning, where only a single component of an input vector is given, for each example. We argue that 1-RFA learning merits special consideration within the wider field of RFA learning. It is the most restrictive form of RFA learning (so that positive results apply in general), and it models a typical ``datafusion'''' scenario, where we have sets of observations from a number of separate sensors, but these sensors are uncorrelated sources. Within this setting we study the well-known class of linear threshold functions, the characteristic functions of Euclidean half-spaces. The sample complexity (i.e. sample-size requirement as a function of the parameters) of this learning problem is affected by the input distribution. We show that the sample complexity is always finite, for any given input distribution, but we also exhibit methods for defining ``bad'''' input distributions for which the sample complexity can grow arbitrarily fast. We identify fairly general sufficient conditions for an input distribution to give rise to sample complexity that is polynomial in the PAC parameters e-1 and d-1. We give an algorithm (using an empirical e-cover) whose sample complexity is polynomial in these parameters and the dimension (number of inputs), for input distributions that satisfy our conditions. The runtime is polynomial in e-1 and d-1 provided that the dimension is any constant. We show how to adapt the algorithm to handle uniform misclassification noise.
PRODUCING A CORRECT CALL-STACK TRACE IN THEOCCASIONAL ABSENCE OF FRAME POINTERS
Authors: Max Copperman
Venue:  (1990)

Optimizing compilers produce code that impedes debugging. An important facility for an interactive debugger of optimized programs is to be able to provide a call-stack trace, listing active subroutines in reverse order of their invocations. This facility relies on information provided by code within each called routine. This paper describes an alternative way to support this facility in the circumstance that this code is optimized away.
Parallel Watershed Algorithm Based on Sequential Scanning
Authors: A. N. Moga, T. Viero, M. Gabbouj, Michael Nolle, Gerald Schreiber, Hans Burkhardt
Venue:  (1995)

The watershed transformation is widely used in morphological image segmentation [1], e.g., in industrial, and biomedical applications, where digital pictures of 512 x 512 pixels, 1K x 1K, or even larger are not uncommon. Therefore, large amount of data and, consequently, complex analysis, entail parallel algorithms. In this paper, a fast SPMD (Single Program Multiple Data) watershed algorithm based on a sequential scannings is rendered. The task performed by the present algorithm is to compute the watershed image by integrating the morphological gradient of the original image. The technique, iterative by nature, is implemented on a multitransputer system (with the Bruijn interconnection network) by repeated scans and message passing among processors until the computation stabilizes. The algorithm is well suited for SIMD (Single Instruction Multiple Data) computers since no ordered queues (see [1,4]) are used. Speedup evaluates the quality of the parallel algorithm.
ON-LINE LEARNING OF LINEAR FUNCTIONS
Authors: Nicholas Littlestone, Philip M. Long, Manfred K. Warmuth
Venue:  (1991)

We present an algorithm for the on-line learning of linear functions which is optimal to within a constant factor with respect to bounds on the sum of squared errors for a worst case sequence of trials. The bounds are logarithmic in the number of variables. Furthermore, the algorithm is shown to be optimally robust with respect to noise in the data (again to within a constant factor). We also discuss an application of our methods to the iterative solution of sparse systems of linear equations.
Mechanical and thermal fatigue of curved composite beams
Authors: L. Figiel, M. Kamiński
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

The main goal of this paper is presentation of computer modeling of the layered composite fatigue delamination under thermal cycling and cyclic compressive shear with the constant amplitude. The considered composite material consists of two components with transversely isotropic linear elastic properties. The fatigue delamination problem is solved using the Linear Elastic Fracture Mechanics (LEFM) approach for interfacial cracks and referred to interface fatigue crack propagation. Then, the problem is analyzed numerically thanks to Finite Element Method (FEM) displacement-based program ANSYS. The number of cycles to composite failure under mechanical load is approximated by the modified Paris-Erdogan law implemented in this program together with the number of thermal cycles required to hold up the fatigue crack growth.
Graph Layout Using Queues
Authors: Lenwood S. Heath, Arnold L. Rosenberg
Venue:  (1989)

We study the problem of laying out the edges of a graph using queues. In a k queue layout, vertices of the graph are placed in some linear order and each edge is assigned to exactly one of the k queues so that the edges assigned to each queue obey a first-in/first-out discipline. This layout problem abstracts a design problem of fault-tolerant processor arrays and a problem of sorting with parallel queues. We relate the queue layout problem to the corresponding stack layout problem using stacks (the book embedding problem) and immediately derive some asymptomic bounds for d-valent graph. We show that every 1-queue graph is a 2-stack graph and that every 1-stack graph is a 2-queue graph. We characterize the 1-queue graphs (they are almost leveled-planar graphs) and prove that the problem of recognizing 1-queue graphs is NP-complete. We give some queue layouts for specific classes of graphs. Relationships to cutwidth, bandwidth, and bifurcators are presented. We show a tradeoff between queuenumber and stacknumber for a fixed linear order of the vertices of G.
AMP: A BUS-BASED PACKET SWITCH DESIGN USING MCM TECHNOLOGY (M.S. thesis)
Authors: Martin Taylor
Venue:  (1991)

AMP is a bus based packet switch implemented as a *silicon-on-silicon* Multi-Chip Module (MCM). The AMP switch system architecture is a special case of a *multi-bus* switching scheme. Such an architecture allows an efficient use of buffering and switching hardware. The implementation targeted MCM technology from the beginning. The fabrication, testing and assembly were done utilizing services which should be made available to academic and research establishments as a MOSIS type brokerage service in the future. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Minimal Parameter Homotopies for the L2 Optimal Model Order Reduction Problem
Authors: Yuzhen Ge, Emmanuel G. Collins, Layne T. Watson, L. D. Davis
Venue:  (1992)

The problem of finding a reduced order model, optimal in the L2 sense, to a given system model is a fundamental one in control system analysis and design. The problem is very difficult without the global convergence of homotopy methods, and a number of homotopy based approaches have been proposed. The issues are the number of degrees of freedom, the well posedness of the finite dimensional optimization problem, and the numerical robustness of the resulting homotopy algorithm. Homotopy algorithms based on several formulations are developed and compared here. The main conclusions are that dimensionality is inversely related to numerical well conditioning and algorithmic efficiency is inversely related to robustness of the algorithm.
Multi-objective evolutionary algorithms: introducing bias among Pareto-optimal solutions
Authors: Kalyanmoy Deb
Venue: Advances in evolutionary computing: theory and applications (2003)

Since the beginning of the 1990s, research and application of muitiobjective evolutionary algorithms (MOEAs) have attracted increasing attention. This is mainly due to the ability of evolutionary algorithms to find multiple Pareto-optimal solutions in one single simulation run. In this chapter, we present an overview of MOEAs and then discuss a particular algorithm in detail. Although MOEAs can find multiple Pareto-optimal solutions, often, users need to impose a particular order of priority to objectives. In this chapter, we present a few classical techniques to identify a preferred or a compromise solution, and finally suggest a biased sharing technique which can be used during the optimization phase to find a biased distribution of Pareto-optimal solutions in the region of interest. The results are encouraging and suggest further application of the proposed strategy to more complex multi-objective optimization problems.
Rotational Position Optimization (RPO) Disk Scheduling
Authors: Walter Burkhard, John Palmer
Venue:  (2001)

Rotational position optimization disk scheduling algorithms utilize seek distance versus rotational distance information implemented as rpo tables (arrays) which are stored in flashmemory within each disk drive. We consider a novel representation scheme for this information reducing the required flashmemory by a factor of more than thirty thereby reducing the manufacturing cost per drive. We present simulation results showing the throughput for conservative and aggressive versions of the scheme as well as comparative results with the standard production drives not using these results.
Target-specific Global Code Improvement: Principles and Applications
Authors: Manuel E. Benitez, Jack W. Davidson
Venue:  (1994)

Current and future high-performance systems require language processors that can generate code that fully exploits the power of the underlying architecture. A key and necessary component of such language processors is a global code improver. This article describes the key principles behind the design and implementation of a global code improver that has been use to construct several high-quality compilers and other program transformation and analysis tools. The code improver, called vpo, employs a paradigm of compilation that has proven to be flexible and adaptableall code improving transformations are performed on a target-specific representation of the program. The aggressive use of this paradigm yields a code improver with several valuable properties. Four properties stand out. First, vpo is language and compiler independent. That is, it has been used to implement compilers for several different computer languages. For the C programming language, it has been used with several front ends each of which generates a different intermediate language. Second, because all code improvements are applied to a single low-level intermediate representation, phase ordering programs are minimized. Third, vpo is easily retargeted and handles a wide variety of architectures. In particular, vpo''s structure allows new architectures and new implementations of existing architectures to be accommodated quickly and easily. Fourth and finally, because of its flexible structure, vpo has several other interesting uses in addition to its primary use in an optimizing compiler. This article describes the principles that have driven the design of vpo and the implications of these principles on vpo''s implementation. The article concludes with a brief description of vpo''s use as a back end with front ends for several different languages, and its use as a key component for the realization of several other applications.
Reduction Operations in Parallel Discrete Event Simulation (PhD Dissertation)
Authors: Carmen Pancerella
Venue:  (1994)

Building on Reynolds''s hardware/software framework for parallel discrete event simulation (PDES), we establish a number of novel and best known results based on the use of reduction-based computing to support PDES. We demonstrate the utility of reduction-based computing to a spectrum of well-known PDES synchronization protocols, such as conservative techniques and Time Warp. We enhance the hardware portion of Reynolds''s framework at three levels: 1) we define a virtual computation model, 2) we develop a functional design, and 3) we present a detailed implementation of this design. Each of the preceding steps is based on correctness criteria we establish here. We develop novel algorithms for performing reduction-based message acknowledgments. We prove the correctness of one of them, a single phase acknowledgment algorithm that takes advantage of the existence of global virtual time. Finally, we introduce target- specific reductions, a very promising strategy for disseminating near-perfect state information in PDES''s. A target-specific reduction is one where each logical process receives synchronization information (reduced values) only from those logical processes on which it is logically dependent. We demonstrate that the computation of target-specific values can have a sub-quadratic sequential time complexity. Supporting empirical results clearly demonstrate that target-specific reductions will provide significant time and space savings in PDES''s.
Query-by-structure approach for the web
Authors: Michael Johnson, Farshad Fotouhi, Sorin Draghici
Venue: Data mining: opportunities and challenges (2003)

This chapter presents three systems that incorporate document structure information into a search of the Web. These systems extend existing Web searches by allowing the user to request documents containing not only specific search words, but also to specify that documents be of a certain type. In addition to being able to search a local database (DB), all three systems are capable of dynamically querying the Web. Each system applies a query-by-structure approach that captures and utilizes structure information as well as content during a query of the Web. Two of the systems also employ neural networks (NNs) to organize the information based on relevancy of both the content and structure. These systems utilize a supervised Hamming NN and an unsupervised competitive NN, respectively. Initial testing of these systems has shown promising results when compared to straight keyword searches.
LogGP: Incorporating Long Messages into the LogP Model --- One step closer towards a realistic model for parallel computation
Authors: Albert Alexandrov, Mihai F. Ionescu, Klaus E. Schauser, Chris Scheiman
Venue:  (1995)

We present a new model of parallel computation---the LogGP model---and use it to analyze a number of algorithms, most notably, the single node scatter (one-to-all personalized broadcast). The LogGP model is an extension of the LogP model for parallel computation which abstracts the communication of fixed-sized short messages through the use of four parameters: the communication latency (L), overhead (o), bandwidth (g), and the number of processors (P). As evidenced by experimental data, the LogP model can accurately predict communication performance when only short messages are sent (as on the CM-5). However, many existing parallel machines have special support for long messages and achieve a much higher bandwidth for long messages compared to short messages (e.g., IBM SP-2, Paragon, Meiko CS-2, Ncube/2). We extend the basic LogP model with a linear model for long messages. This combination, which we call the LogGP model of parallel computation, has one additional parameter, G, which captures the bandwidth obtained for long messages. Experimental data collected on the Meiko CS-2 shows that this simple extension of the LogP model can quite accurately predict communication performance for both short and long messages. This paper discusses algorithm design and analysis under the new model, examining the all-to-all remap, FFT, and radix sort. We also examine, in more detail, the single node scatter problem. We derive solutions for this problem and prove their optimality under the LogGP model. These solutions are qualitatively different from those obtained under the simpler LogP model, reflecting the importance of capturing long messages in a model.
The Case for Feedback Control Real-Time Scheduling
Authors: John A. Stankovic, Chenyang Lu, Sang H. Son
Venue:  (1998)

Despite the significant body of results in real-time scheduling, many real world problems are not easily supported. While algorithms such as Earliest Deadline First, Rate Monotonic, and the Spring scheduling algorithm can support sophisticated task set characteristics (such as deadlines, precedence constraints, shared resources, jitter, etc.), they are all "open loop" scheduling algorithms. Open loop refers to the fact that once schedules are created they are not "adjusted" based on continuous feedback. While open-loop scheduling algorithms can perform well in static or dynamic systems in which the workloads can be accurately modeled, they can perform poorly in unpredictable dynamic systems, i.e., systems whose workloads cannot be accurately modeled. Unfortunately, many real-world complex systems are dynamic and unpredictable. In addition, most scheduling paradigms assume that timing requirements are known and fixed, while in real systems timing requirements are more flexible. For example, instead of a single fixed deadline for a task, a deadline range might be acceptable to the physical system. If this range was passed to the scheduling system, more robust scheduling could be possible. In this paper, we present a new scheduling paradigm, which we call feedback control real-time scheduling. Feedback control real-time scheduling will define error terms for schedules, monitor the error, and continuously adjust the schedules to maintain stable performance. Feedback control real-time scheduling will be able to deal with dynamic systems that are both resource insufficient and with unpredictable workload. It can also be integrated with flexible real-time requirements. In this paradigm, the scheduling algorithms regard the computer system as a control system with the scheduler as the controller, and integrate practical feedback control techniques into scheduling algorithms. This paper presents a practical feedback control real-time scheduling algorithm, FC-EDF, which is a starting point in the long-term endeavor of creating a theory and practice of feedback control scheduling. Research results will apply to many real world systems including real-time database applications, defense applications, agile manufacturing, and distributed multimedia.