ppxscal/embedding_network huggingface dataset:
On the Asymptotical Optimality of Multilayered Decentralized Consensus Protocol
Authors: Cheng-Ru Lin, Ming-Syan Chen
Venue: IEEE Transactions on Parallel and Distributed Systems (2002)

A decentralized consensus protocol refers to a process for all nodes in a distributed system to collect the information/status from every other node and reach a consensus among them. Two classes of decentralized consensus protocols have been studied before: the one without an initiator and the one with an initiator. While the one without an initiator has been well studied in the literature, it is noted that the prior protocols with an initiator mainly relied upon the one without an initiator and thus did not fully exploit the intrinsic properties of having an initiator. By exploiting the concept of multilayered execution, we develop in this paper an efficient multilayered decentralized consensus protocol for a distributed system with an initiator. By adapting itself to the number of nodes in the system, the proposed protocol can determine a proper layer for execution and reach the consensus in the minimal numbers of message steps while incurring a much smaller number of messages than required by prior works. Several illustrative examples are given and performance analysis of the proposed algorithm is conducted to provide many insights into the problem studied. It is shown that the decentralized consensus protocols developed in this paper for the case of having an initiator significantly outperform prior schemes. Specifically, it is proven that 1) the ratio of the average number of messages incurred by the proposed algorithm to that by the prior method approaches zero as the number of nodes increases and 2) the proposed algorithm is asymptotically optimal in the sense that the message number required by the proposed algorithm and that of the optimal one are asymptotically of the same complexity with respect to the number of nodes in the system, showing the very important advantage of the proposed algorithm.
Developing Highly Reliable Software
Authors: R. m. Suresh babu, B. b. Biswas, G. Govindarajan
Venue: IEEE Micro (1997)

With growing application of microcomputers for safety critical systems there is a need to assure high reliability of the software used in hese systems. This article describes our experience in development of one such highly reliable software: a real-time executive for safety critical systems of Nuclear Power Plants. The most practical method to assure software quality is by controlling the software development process. Advanced planning and reviews help to ensure that the software objectives are satisfied t all intermediate stages of the development. Statistical quality assurance demonstrates quality of the software product as well as the development process; this enhances confidence in the software. The article concludes by summarizing the results of evaluation of the software development approach used in this project.
Quasi-linear sequence transformations and their construction
Authors: A. Lembarki
Venue: Applied Numerical Mathematics (2002)

Regular quasi-linear sequence transformations are characterized by means of a system of two linear partial differential equations. The general solution is obtained and the class of linear solutions is specified. Construction of quasi-linear processes is interpreted as a Cauchy problem.
The D editor: a new interactive parallel programming tool
Authors: Seema Hiranandani, Ken Kennedy, Chau Wen Tseng, Scott Warren
Venue: Proceedings of the 1994 ACM/IEEE conference on Supercomputing (1994)

Fortran D and High Performance Fortran are languages designed to support efficient data-parallel programming on a variety of parallel architectures. The goal of the D Editor is to provide a tool that allows scientists to use these languages efficiently. The D Editor combines analyses for shared-memory machines and compiler optimizations for distributed-memory machines. By cooperating with the underlying compiler, it can provide novel information on partitioning, parallelism, and communication based on compile-time analysis at the level of the original Fortran program. The D Editor uses color coding and a collection of graphical displays to help the user to zoom in on portions of the program containing sequentialized code or expensive communication. The prototype implementation is useful for interactively displaying the results of compile-time analysis; however, it has a number of shortcomings that must be addressed. Future enhancements will provide additional advice and transformation capabilities. We believe the D Editor is representative of a new generation of tools that will be needed to assist scientists to fully exploit languages such as High Performance Fortran.
Natural Majorization of the Quantum Fourier Transformation in Phase-Estimation Algorithms
Authors: Román Orús, José I. Latorre, Miguel A. Martín-Delgado
Venue: Quantum Information Processing (2002)

We prove that majorization relations hold step by step in the Quantum Fourier Transformation (QFT) for phase-estimation algorithms. Our result relies on the fact that states which are mixed by Hadamard operators at any stage of the computation only differ by a phase. This property is a consequence of the structure of the initial state and of the QFT, based on controlled-phase operators and a single action of a Hadamard gate per qubit. The detail of our proof shows that Hadamard gates sort the probability distribution associated to the quantum state, whereas controlled-phase operators carry all the entanglement but are immaterial to majorization. We also prove that majorization in phase-estimation algorithms follows in a most natural way from unitary evolution, unlike its counterpart in Grover's algorithm.PACS: 03.67.-a, 03.67.Lx
Lyapunov Equation for the Stability of 2-D Systems
Authors: Pierre-Alexandre Bliman
Venue: Multidimensional Systems and Signal Processing (2002)

An analogue of the characterization of asymptotic stability of the 1-D systems by the solvability of associated Lyapunov equation is proposed here for 2-D systems. It is shown that internal stability of Roesser model is equivalent to the feasibility of some linear matrix inequality (LMI), related to quadratic Lyapunov functions.
Rule-Based Inferencing Functions for APL Applications
Authors: Yonathan Bard
Venue: IEEE Expert: Intelligent Systems and Their Applications (1988)

The inclusion of inferencing capabilities in applications written in APL is discussed. A set of routines called APLPIE (APL programmed inference engine) that provide such facilities is described. It is shown how to write and prepare rules for use by the inferencing functions, and the functions and methods used when searching for conclusions are examined. Features that enhance inferencing and features for tracing its sessions, to facilitate testing and debugging and to explain its conclusions, are also described. Some examples are given.
A Tutorial on CRC Computations
Authors: Tenkasi V. Ramabadran, Sunil S. Gaitonde
Venue: IEEE Micro (1988)

The theory of cyclic redundancy codes (CRS) is reviewed. Four software algorithms for performing CRC computations are described: table lookup, reduced table lookup, on-the-fly, and wordwise. They are compared in terms of their speeds and storage requirements.
Connective Fault Tolerance in Multiple-Bus Systems
Authors: Hung-Kuei Ku, John P. Hayes
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

We present an efficient approach to characterizing the fault tolerance of multiprocessor systems that employ multiple shared buses for interprocessor communication. Of concern is connective fault tolerance, which is defined as the ability to maintain communication between any two fault-free processors in the presence of faulty processors, buses, or processor-bus links. We introduce a model called processor-bus-link (PBL) graphs to represent a multiple-bus system's interconnection structure. The model is more general than previously proposed models, and has the advantages of simple representation, broad application, and the ability to model partial bus failures. The PBL graph implies a set of component adjacency graphs that highlights various connectivity features of the system. Using these graphs, we propose a method for analyzing the maximum number of faults a multiple-bus system can tolerate, and for identifying every minimum set of faulty components that disconnects the processors of the system. We also analyze the connective fault tolerance of several proposed multiple-bus systems to illustrate the application of our method.
A Dynamic Priority Assignment Technique for Streams with (m, k)-Firm Deadlines
Authors: Parameswaran Ramanathan, Moncef Hamdaoui
Venue: IEEE Transactions on Computers (1995)

The problem of scheduling multiple streams of real-time customers. is addressed in this paper. The paper first introduces the notion of (m, k)-firm deadlines to better characterize the timing constraints of real-time streams. More specifically, a stream is said to have (m, k)-firm deadlines if at least m out of any k consecutive customers must meet their deadlines. A stream with (m, k)-firm deadlines experiences a dynamic failure if fewer than m out of any k consecutive customers meet their deadlines.The paper then proposes a priority-based policy for scheduling N such streams on a single server to reduce the probability of dynamic failure. The basic idea is to assign higher priorities to customers from streams that are closer to a dynamic failure so as to improve their chances of meeting their deadlines. The paper proposes a heuristic for assigning these priorities. The effectiveness of this approach is evaluated through simulation under various customer arrival and service patterns. The scheme is compared to a conventional scheme where all customers are serviced at the same priority level and to an imprecise computation model approach. The evaluation shows that substantial reductions in the probability of dynamic failure are achieved when the proposed policy is used.
NMR Nomenclature: nuclear spin properties and conventions for chemical shifts (IUPAC Recommendations 2001)
Authors: Robin K. Harris, Edwin D. Becker, Sonia M. Cabral De Menezes, Robin Goodfellow, Pierre Granger
Venue: Concepts in Magnetic Resonance: an Educational Journal (2002)

A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, Ξ, of the resonance frequency of a given nuclide to that of the primary reference, the 1H resonance of tetramethylsilane (TMS) in dilute solution (volume fraction, φ > 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples and values of Ξ for secondary references on the unified scale are listed, many of which are the results of new measurements. Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, δ, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic-angle spinning. In all, nine new recommendations relating to chemical shifts are made. Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with non-zero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and linewidth factors (where appropriate).
Massively Parallel Algorithms for Trace-Driven Cache Simulations
Authors: D. M. Nicol, A. G. Greenberg, B. D. Lubachevsky
Venue: IEEE Transactions on Parallel and Distributed Systems (1994)

Considers the use of massively parallel architectures to execute a trace-driven simulation of a single cache set. A method is presented for the least-recently-used (LRU) policy, which, regardless of the set size C, runs in time O(log N) using N processors on the EREW (exclusive read, exclusive write) parallel model. A simpler LRU simulation algorithm is given that runs in O(C log N) time using N/log N processors. We present timings of this algorithm's implementation on the MasPar MP-1, a machine with 16384 processors. A broad class of reference-based line replacement policies are considered, which includes LRU as well as the least-frequently-used (LFU) and random replacement policies. A simulation method is presented for any such policy that, on any trace of length N directed to a C line set, runs in O(C log N) time with high probability using N processors on the EREW model. The algorithms are simple, have very little space overhead, and are well suited for SIMD implementation.
Reduction of quantum decoherence in non-local resistance measurement
Authors: K. Kobayashi, H. Aikawa, S. Katsumoto, Y. Iye
Venue: Microelectronic Engineering (2002)

We have found that the coherence of electrons is better retained in a non-local resistance measurement compared to in the conventional four-terminal resistance setup which is pervasively used. The observed configuration-dependent decoherence poses an important question on pictures of the mechanism of quantum decoherence.
Neural Net and Boolean Satisfiability Models of Logic Circuits
Authors: Srimat Chakradhar, Vishwani Agrawal, Michael Bushnell, Thomas Truong
Venue: IEEE Design Test (1990)

Two recently proposed models of digital circuits that are useful in parallel test-generation methods are described. In the neural net model, the input and output signal states of a logic gate are related through an energy function. In the Boolean satisfiability model, a logic gate is represented by a truth expression. How the equivalence of these models offers the flexibility of using the same algorithm in two different environments is shown. The models can be used in parallel methods for solving CAD problems such as simulation and test generation.
REQUIREMENTS: Requirements and Testing: Seven Missing-Link Myths
Authors: Dorothy Graham
Venue: IEEE Software (2002)

Testing expert Dorothy Graham asserts that we can save a great deal of time and money if testers are involved in testing requirements.If the requirements have some consistent quality criteria, testers can raise questions and find problems before we turn them into code.
Probability Intervals Over Influence Diagrams
Authors: K. W. Fertig, J. S. Breese
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1993)

A mechanism for performing probabilistic reasoning in influence diagrams using interval rather than point-valued probabilities is described. Procedures for operations corresponding to conditional expectation and Bayesian conditioning in influence diagrams are derived where lower bounds on probabilities are stored at each node. The resulting bounds for the transformed diagram are shown to be the tightest possible within the class of constraints on probability distributions that can be expressed exclusively as lower bounds on the component probabilities of the diagram. Sequences of these operations can be performed to answer probabilistic queries with indeterminacies in the input and for performing sensitivity analysis on an influence diagram. The storage requirements and computational complexity of this approach are comparable to those for point-valued probabilistic inference mechanisms.
Real-Time Image Processing on a Custom Computing Platform
Authors: Peter M. Athanas, A. Lynn Abbott
Venue: Computer (1995)

Hardware designers typically must perform extensive behavioral testing of a new concept before proceeding with an implementation. Due to the enormous processing time required to simulate a complex image-processing system executing a VHDL model with a representative data set even on a fast workstation is not practical. Days even weeks, are commonly needed to simulate the processing of a full-sized image. And since some applications process sequences of images, designers may need several hundred image simulations to adequately analyze only a few seconds of data. Because of this, they may be forced into a trade-off between how much testing can be afforded versus an acceptable risk in allowing a silicon iteration. The authors discuss an alternative, automated approach: transforming the structural representation (or transforming a behavioral model) into a real-time implementation. With their VTSplash custom computing platform, a designer can proceed from a behavioral description of the image-processing task to a functioning prototype that can perform the task at full speed (rapid prototyping). Reconfiguration from one image-processing task to another takes just seconds. The authors explore the utility of custom computing machinery for accelerating the development, testing, and prototyping of a diverse set of image-processing applications. They describe several implemented image-processing tasks and conclude with task performance evaluation.
System Complexity and Integrated Diagnostics
Authors: William R. Simpson, John W. Sheppard
Venue: IEEE Design Test (1991)

An overview of a complete approach to integrated diagnostics is given. The approach is centered around an information-flow model and incorporates techniques from information fusion and artificial intelligence to guide analyses. The concept of integrated diagnosis is explained, and the model is examined. The authors show how to analyze testability, evaluate fault diagnosis, and create maintenance aids.
A Correlation-Relaxation-Labeling Framework for Computing Optical Flow - Template Matching from a New Perspective
Authors: Qing X. Wu
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

Optical flow estimation is discussed based on a model for time-varying images more general than that implied in the work of Horn and Schunk [21]. The emphasis is on applications where low contrast imagery, non-rigid or evolving object patterns movement, as well as large interframe displacements are encountered. Template matching is identified as having advantages over point correspondence and the gradient-based approach in dealing with such applications. The two fundamental uncertainties in feature matching procedures, whether it is template matching or feature point correspondences, are discussed. Correlation template matching procedures are established based on likelihood measurement. A new method for determining optical flow is developed by combining template matching and relaxation labeling. In this method, a number of candidate displacements for each template and their respective likelihood measures are first determined. Then, relaxation labeling is employed to iteratively update each candidate¿s likelihood by requiring smoothness within a motion field. Real cloud images taken from meteorological satellites are used to test the usefulness of this method. It is shown in this application that the new method can deal effectively with the uncertainty of multiple peak (multi-modal) correlation surfaces encountered in template matching. The results show significant improvement when compared to that of the maximum cross correlation (MCC), which has been operationally used for cloud tracking, and to that of the method of Barnard and Thompson, which estimates displacements based on combining point correspondences with relaxation labeling.
The WALRAS Algorithm: A Convergent Distributed Implementation of General Equilibrium Outcomes
Authors: John Q. Cheng, Michael P. Wellman
Venue: Computational Economics (1998)

The WALRAS algorithm calculates competitive equilibria via a distributed tatonnement-like process, in which agents submit single-good demand functions to market-clearing auctions. The algorithm is asynchronous and decentralized with respect to both agents and markets, making it suitable for distributed implementation. We present a formal description of this algorithm, and prove that it converges under the standard assumption of gross substitutability. We relate our results to the literature on general equilibrium stability and some more recent work on decentralized algorithms. We present some experimental results as well, particularly for cases where the assumptions required to guarantee convergence do not hold. Finally, we consider some extensions and generalizations to the WALRAS algorithm.
Compile-Time Techniques for Data Distribution in Distributed Memory Machines
Authors: J. Ramanujam, P. Sadayappan
Venue: IEEE Transactions on Parallel and Distributed Systems (1991)

A solution to the problem of partitioning data for distributed memory machines is discussed. The solution uses a matrix notation to describe array accesses in fully parallel loops, which allows the derivation of sufficient conditions for communication-free partitioning (decomposition) of arrays. A series of examples that illustrate the effectiveness of the technique for linear references, the use of loop transformations in deriving the necessary data decompositions, and a formulation that aids in deriving heuristics for minimizing a communication when communication-free partitions are not feasible are presented.
Microprocessors, Microcontrollers, and Systems in the New Millennium
Authors: Chris Herring
Venue: IEEE Micro (2000)

Next-generation architectures must become more flexible to meet the inevitable changes to market and customer requirements. To ensure flexibility, architects and designers need to face these realities.
Convergence of Semi-Lagrangian Approximations to Convex Hamilton-Jacobi Equations under (Very) Large Courant Numbers
Authors: Roberto Ferretti
Venue: SIAM Journal on Numerical Analysis (2002)

We consider a class of semi-Lagrangian high-order approximation schemes for convex Hamilton--Jacobi equations. In this framework, we prove that under certain restrictions on the relationship between $\Delta x$ and $\Delta t$, the sequence of approximate solutions is uniformly Lipschitz continuous and hence, by consistency, that it converges to the exact solution. The argument is suitable for most reconstructions of interest, including high-order polynomials and ENO reconstructions.
Maintaining Temporal Consistency: Pessimistic vs. Optimistic Concurrency Control
Authors: Xiaohui (Carol) Song, Jane W. S. Liu
Venue: IEEE Transactions on Knowledge and Data Engineering (1995)

We study the performance of concurrency control algorithms in maintaining temporal consistency of shared data in hard real-time systems. In our model, a hard real-time system consists of periodic tasks which are either write-only, read-only or update transactions. Transactions may share data. Data objects are temporally inconsistent when their ages and dispersions are greater than the absolute and relative thresholds allowed by the application. Real-time transactions must read temporally consistent data in order to deliver correct results. Based on this model, we have evaluated the performance of two well-known classes of concurrency control algorithms that handle multiversion data: the two-phase locking and the optimistic algorithms, as well as the rate-monotonic and earliest-deadline-first scheduling algorithms. The effects of using the priority inheritance and stack-based protocols with lock-based concurrency control are also studied.