ppxscal/embedding_network huggingface dataset:
Bruhat Decomposition and Numerical Stability
Authors: O. H. Odeh, D. D. Olesky, P. vanden Driessche
Venue: SIAM Journal on Matrix Analysis and Applications (1998)

For a real nonsingular n-by-n matrix A, there exists a decomposition $A=V\Pi U$, where $\Pi$ is a permutation matrix and V,U are upper triangular matrices. When $\Pi^TV\Pi$ is lower triangular and U is normalized, such a decomposition is called the left Bruhat decomposition of A. An algorithm for computing the left Bruhat decomposition is given. For classes of matrices introduced by Wilkinson and recently (from a practical application) by Foster that have an exponential growth factor when Gaussian elimination with partial pivoting (GEPP) is applied, left Bruhat decomposition has at most linear growth. A partial pivoting strategy for Bruhat decomposition is also developed, and an explicit equivalence between GEPP and Bruhat decomposition with partial pivoting (BDPP) is derived. This equivalence implies that the growth factor for GEPP on A equals the growth factor for BDPP on $\rho A^T$, where $\rho$ is the permutation matrix that reverses the rows of $A^T$. BDPP is shown to give a growth factor of at most 2 when applied to any matrix for which GEPP gives the maximal growth factor of 2 n - 1.
Perturbation Formula for Regular Free Boundaries in Elliptic and Parabolic Obstacle Problems
Authors: Srdjan Stojanovic
Venue: SIAM Journal on Control and Optimization (1997)

The perturbation formula for regular free boundaries with respect to various parameters of the obstacle problem, which has been known in the case of elliptic problems, is proved by a new method. The method introduced here extends easily to parabolic problems as well. This enables a study of optimal control of regular free boundaries in elliptic and parabolic obstacle problems.
Evaluation of scheduling techniques on a SPARC-based VLIW testbed
Authors: Seongbae Park, SangMin Shim, Soo-Mook Moon
Venue: Proceedings of the 30th annual ACM/IEEE international symposium on Microarchitecture (1997)

The performance of Very Long Instruction Word (VLIW) microprocessors depends on the close cooperation between the compiler and the architecture. This paper evaluates a set of important compilation techniques and related architectural features for VLIW machines. The evaluation is performed on a SPARC-based VLIW testbed where gcc-generated optimized SPARC code is scheduled into high-performance VLIW code. As a base scheduling compiler, we experiment with three core scheduling techniques including enhanced pipeline scheduling, all-path speculation, and renaming. We analyze the characteristics of the useful and useless ALUs in each cycle to see how many of those ALUs execute non-speculative operations, speculative operations, and copies, respectively. Then, we evaluate the following compilation techniques: software pipelining, loop unrolling, non-greedy enhanced pipeline scheduling, profile-based all-path speculation, trace-based speculation, renaming, restricted speculative loads, and memory disambiguation. Since we experiment on a uniform testbed based on a detailed analysis of ALUs, our evaluation provides an useful insight on the performance impact of these techniques.
A case study in using two-level control stores
Authors: Onat Menzilcioglu
Venue: Proceedings of the 20th annual workshop on Microprogramming (1987)

A two-level control store can reduce storage requirements of microprograms without affecting microprogrammability, which is important for a processor programmed directly in microcode. This paper presents a case study investigating how to use a two-level control store effectively. The study is based on Warp cell, a high-performance, microprogrammable processor used in a systolic array computer called Warp. Warp cell is programmed directly in microcode by an optimizing compiler and uses wide horizontal microinstructions with over 200 bits. Two methods which can increase the effectiveness of using a two-level control store have been considered. First, control store configuration can be adjusted so that the storage of an instruction can be partitioned among microstore and one or more nanostores to maximize storage efficiency. Second, it is possible to increase storage reduction of microprograms by exploiting insignificant and symmetric fields in instructions in mapping microprograms to the control store. It has been found that the average storage reduction for Warp cell programs can be increased from 41% in a straightforward two-level control store implementation to 72% by using these methods.
A Single-Chip MPEG/Audio Decoder LSI Based on a Compact DecodingAlgorithm
Authors: Masahiro Iwadare, Hideto Takano, Yoshitaka Shibuya, Hideki Sakamoto, Takeshi Kuwajima, Osamu Kitabatake, Naoko Kobayashi
Venue: Journal of VLSI Signal Processing Systems (1997)

A single-chip decoder LSI is developed for ISO/IEC MPEG (the International Organisation for Standardisation/the International Electrotechnical Commission, Moving Pictures Expert Group) audio. The applicable layers are Layer I and II of MPEG-1 and MPEG-2/Lower-Sampling-Frequency Mode. A fast calculation algorithm, which is also effective for on-chip memory reduction, is incorporated in audio signal synthesis. The reliability in bitstream synchronization is improved by including bitstream inconsistency detection. Bitstream error concealment by repeating previous audio data is supported. The decoding delay is adjustable when an optional external memory is connected to the LSI.
System level fixed-point design based on an interpolative approach
Authors: Markus Willems, Volker Bürsgens, Holger Keding, Thorsten Grötker, Heinrich Meyr
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

The design process for fixed-point implementations eitherin software or in hardware requires a bit-true specificationof the algorithm in order to analyze quantization effectson an algorithmical level, abstracting from implementationaldetails.On the other hand, system design starts froma floating-point description into a fixed-point description becomesnecessary.Within this paper we present a tool thatallows an automated, interactive transformation from floating-pointANSI-C into a bit-true specification based ona new data type fixed that is introduced as an extensionto ANSI-C.The concept is rooted in a sophisticated datadependency analysis that allows to handle control structuresas well as pointers.It is part of the fixed-point designenvironment FRIDGE which includes an advanced simulatorthat covers the extended ANSI-C syntax as well astarget specific compilers which allow to generate efficientfixed-point implementations either for HW or for SW, startingfrom the bit-true algorithm specification.
Conditions for Strong Stabilizabilities ofn-Dimensional Systems
Authors: Jiang Qian Ying
Venue: Multidimensional Systems and Signal Processing (1998)

This paper presents two computational criteria concerning the strong stabilizabilities of SISO (single-input single-output) n-D shift-invariant systems. The first one is an alternative necessary and sufficient condition for an n-D system to be stabilizable by a stable complex controller, which is an explicitly computable geometric equivalent to the topological one recently derived by Shiva Shankar. The second one is a necessary and sufficient condition for the stabilizability by a stable real controller, which can be viewed as a generalization of the well-known Youla&lsquo;s parity interlacing property for the 1-D case. Furthermore, related prolems for computational testing of the criteria are summarized and some basic ideas on potential solution methods based on the cylindrical algebraic decomposition of algebraic varieties are outlined.
A Constant-Potential Infeasible-Start Interior-Point Algorithmwith Computational Experiments and Applications
Authors: Abbas Seifi, Levent Tunçel
Venue: Computational Optimization and Applications (1998)

We present a constant-potential infeasible-start interior-point (INFCP) algorithm for linear programming (LP) problems with a worst-case iteration complexity analysis as well as some computational results.The performance of the INFCP algorithm is compared to those of practical interior-point algorithms. New features of the algorithm include a heuristic method for computing a &ldquo;good&rdquo; starting point and a procedure for solving the augmented system arising from stochastic programming with simple recourse. We also present an application to large scale planning problems under uncertainty.
Optimization method for broadband modem FIR filter design using common subexpression elimination
Authors: Robert Pasko, Patrick Schaumont, Veerle Derudder, Daniela Durackova
Venue: Proceedings of the 10th international symposium on System synthesis (1997)

An approach for broadband modem FIR filter design optimization is presented. It addresses the minimization of the number of adder-subtractors used in the hardware implementation of a FIR filter (Multiple Constant Multiplication problem). The method is based on identification and elimination of n-bit pattern common subexpressions in a set of filter coefficients by means of an exhaustive search. We give an algorithm description of our solution and demonstrate the performance on selected examples. A comparison of the results obtained by other authors is made and finally optimization and synthesis results on a realistic example, a 64-tap root-raised-cosine filter with 10 bit CSD coefficients is given.
Batching methods in simulation output analysis: what we know and what we don't
Authors: Bruce W. Schmeiser, Wheyming Tina Song
Venue: Proceedings of the 28th conference on Winter simulation (1996)

As an advanced tutorial, we discuss batching methods for determining point-estimator precision for steady-state simulation experiments. We emphasize batching methods in which each batch provides a point estimator analogous to that of the experiment, but we mention other methods that use batches, especially the more-general idea of standardized time series. Despite the preponderance of literature on confidence-interval estimation for the mean using adjacent nonoverlapping batches, we focus on estimating the point estimator's standard error and consider both general point estimators and general batching relationships. Literature on multivariate batching exists, but we focus on the univariate problem. We consider the initial-transient problem only in passing. Specific issues include form of the point estimator, definition of the batch statistics, form of the batch-statistics estimator, optimal batch size (including various definitions of optimal) and determining batch size. This paper is a short summary of the issues, with a fairly complete bibliography.
Network text editor (NTE): A scalable shared text editor for the MBone
Authors: Mark Handley, Jon Crowcroft
Venue: ACM SIGCOMM Computer Communication Review (1997)

IP Multicast, Lightweight Sessions and Application Level Framing provide guidelines by which multimedia conferencing tools can be designed, but they do not provide specific solutions. In this paper, we use these design principles to guide the design of a multicast based shared editor, and examine the consequences of taking a loose consistency approach to achieve good performance in the face of network failures and losses.
Comparing File Copies with at Most Three Disagreeing Pages
Authors: F. K. Hwang, P. J. Wan
Venue: IEEE Transactions on Computers (1997)

Recently, Metzner gave a parallel algorithm to identify two disagreeing pages in comparing two replicated file copies. We show that this algorithm can also identify three disagreeing pages, if one additional comparison is allowed to resolve some possible ambiguity. We also discuss the relation between the file-copy problem and the group testing problem which has been widely studied.
Evaluating surgical block schedules using computer simulation
Authors: Daniel R. Murphy, Steven D. Duket, Elliot Sigal
Venue: Proceedings of the 17th conference on Winter simulation (1985)

This paper describes the use of a computer simulation model in evaluating the scheduling of surgical patients in an operating room. The concepts of block scheduling are discussed. An actual application of the model is described. Example inputs, outputs, and uses of the model are presented.
Regularization of Singular Systems by Derivative and Proportional Output Feedback
Authors: D. L. Chu, H. C. Chan, D. W. C. Ho
Venue: SIAM Journal on Matrix Analysis and Applications (1998)

The problem of the regularization of singular systems by derivative and proportional output feedback is studied. Necessary and sufficient conditions are given to guarantee the existence of a derivative and proportional output feedback such that the closed-loop system is regular and of index at most 1. It is also shown that the closed-loop system becomes strongly controllable and observable by using this feedback.
Allocation of Periodic Task Modules with Precedence and Deadline Constraints in Distributed Real-Time Systems
Authors: Chao-Ju Hou, Kang G. Shin
Venue: IEEE Transactions on Computers (1997)

This paper addresses the problem of allocating (assigning and scheduling) periodic task modules to processing nodes in distributed real-time systems subject to task precedence and timing constraints. Using the branch-and-bound technique, a module allocation scheme is proposed to find an "optimal" allocation that maximizes the probability of meeting task deadlines.The task system within a planning cycle is first modeled with a task flow graph which describes computation and communication modules, as well as the precedence constraints among them. To incorporate both timing and logical correctness into module allocation, the probability of meeting task deadlines is used as the objective function. The module allocation scheme is then applied to find an optimal allocation of task modules in a distributed system. The timing aspects embedded in the objective function drive the scheme not only to assign task modules to processing nodes, but also to use a module scheduling algorithm (with polynomial time complexity) for scheduling all modules assigned to each node, so that all tasks may be completed in time.In order to speed up the branch-and-bound process and to reduce the computational complexity, a dominance relation is derived from the requirement of timely completion of tasks and use to eliminate the possibility of generating vertices in the state-space search tree, which never lead to an optimal solution, and an upper bound of the objective function is derived for every partial allocation with which the scheme determines whether or not to prune the corresponding intermediate vertex in the search tree. Several numerical examples are presented to demonstrate the effectiveness and practicality of the proposed scheme.
Performance degradation due to multiprogramming and system overheads in real workloads: case study on a shared memory multiprocessor
Authors: R. T. Dimpsey, R. K. Iyer
Venue: Proceedings of the 4th international conference on Supercomputing (1990)

In this paper, performance degradation specifically due to the multiprogramming (MP) overhead in a parallel execution environment is quantified. In addition, total system overhead is also measured. A methodology, which estimates the MP overhead present in real workloads, is illustrated with real measurements taken on an Alliant FX/80 running Xylem (Cedar's operating system). It is found that MP overhead usually consumes between 10% and 23% of the processing power available to parallel programs. Total system overhead usually consumes between 12% and 30% of the parallel environment processing power, but is found to be as high as 82.1%. The mean MP overhead is determined to be 16% which is well over half the total system overhead executed on the system (the mean system overhead is determined to be 24% of the processing power). It is found that MP overhead, total system overhead, and application completion time are all moderately correlated. Relationships between the characteristics of a workload and the overhead measurements indicate that processor utilization and to a lesser degree paging are moderately correlated with the overhead present in the workload. It is also found that MP overhead is statistically independent of the number of parallel jobs in the system, while total system overhead is not.
The TSIMMIS Approach to Mediation: Data Models and Languages
Authors: Hector Garcia-Molina, Yannis Papakonstantinou, Dallan Quass, Anand Rajaraman, Yehoshua Sagiv, Jeffrey Ullman, Vasilis Vassalos, Jennifer Widom
Venue: Journal of Intelligent Information Systems (1997)

TSIMMIS&mdash;The Stanford-IBM Manager of Multiple Information Sources&mdash;is a system for integrating information. It offers a data model and a common query language that are designed to support the combining of information from many different sources. It also offers tools for generating automatically the components that are needed to build systems for integrating information. In this paper we shall discuss the principal architectural features and their rationale.
VLSI design synthesis with testability
Authors: Catherine H. Gebotys, Mohamed I. Elmasry
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

A VLSI design synthesis approach with testability, area, and delay constraints is presented. This research differs from other synthesizers by implementing testability as part of the VLSI design solution. A binary tree data structure is used throughout the testable design search. Its bottom up and top down tree algorithms provide datapath allocation, constraint estimation, and feedback for design exploration. The partitioning and two dimensional characteristics of the binary tree structure provide VLSI design floorplans and global information for test incorporation. An elliptical wave filter example was used to illustrate the design synthesis with testability constraints methodology. Test methodologies such as multiple chain scan paths and BIST with different test schedules were explored. Design Scores comprised of area, delay, fault coverage, and test length were computed and graphed. Results show that the 'best' testable design solution is not always the same as that obtained from the 'best' design solution of an area and delay based synthesis search.
Garbage collection in generic libraries
Authors: Gor V. Nishanov, Sibylle Schupp
Venue: Proceedings of the 1st international symposium on Memory management (1998)

This paper demonstrates a unified and garbage-collector independent way to describe the information required for precise collection. Thereby it is possible to construct, a library that can be used with various garbage collectors, without modifying the code of the library or the collector itself. The library design presented applies the adaptor idiom of generic programming which guarantees no overhead incurred if the library is used with manual allocators or with garbage collectors that do not require programmer cooperation. As an illustration of our approach we provide sample adaptors for Bartlett's and CMM primary collectors. We also show that the Standard Template Library (STL) can be easily modified to become garbage-collector aware.
An interactive program to approximate double integrals: an easy to use interface for Cubpack++
Authors: Bart Maerten, Ronald Cools
Venue: ACM SIGNUM Newsletter (1997)

Using Cubpack++ to approximate a double integral requires from users that they write a small C++ program. Although example programs are provided, this still introduces a treshold. This short note describes an interface to Cubpack++ that relieves users from any need to write C++.
CHILD: A First Step Towards Continual Learning
Authors: Mark B. Ring
Venue: Machine Learning (1997)

Continual learning is the constant development of increasingly complex behaviors; the process of building more complicated skills on top of those already developed. A continual-learning agent should therefore learn incrementally and hierarchically. This paper describes CHILD, an agent capable of Continual, Hierarchical, Incremental Learning and Development. CHILD can quickly solve complicated non-Markovian reinforcement-learning tasks and can then transfer its skills to similar but even more complicated tasks, learning these faster still.
Modular object-oriented programming with units and mixins
Authors: Robert Bruce Findler, Matthew Flatt
Venue: Proceedings of the third ACM SIGPLAN international conference on Functional programming (1998)

Module and class systems have evolved to meet the demand for reuseable software components. Considerable effort has been invested in developing new module and class systems, and in demonstrating how each promotes code reuse. However, relatively little has been said about the interaction of these constructs, and how using modules and classes together can improve programs. In this paper, we demonstrate the synergy of a particular form of modules and classes---called units and mixins, respectively---for solving complex reuse problems in a natural manner.
On the power and limitations of strictness analysis
Authors: R. Sekar, I. V. Ramakrishnan, P. Mishra
Venue: Journal of the ACM (JACM) (1997)

Strictness analysis is an important technique for optimization of lazy functional languages. It is well known that all strictness analysis methods are incomplete, i.e., fail to report some strictness properties. In this paper, we provide a precise and formal characterization of the loss of information that leads to this incompletenss. Specifically, we establish the following characterization theorem for Mycroft's strictness analysis method and a generalization of this method, called ee-analysis, that reasons about exhaustive evaluation in nonflat domains: Mycroft's method will deduce a strictness property for program P iff the property is independent of any constant appearing in any evaluation of P. To prove this, we specify a small set of equations, called E-axioms, that capture the information loss in Mycroft's method and develop a new proof technique called E-rewriting. E-rewriting extends the standard notion of rewriting to permit the use of reductions using E-axioms interspersed with standard reduction steps. E-axioms are a syntactic characterization of information loss and E-rewriting provides and algorithm-independent proof technique for characterizing the power of analysis methods. It can be used to answer questions on completeness and incompleteness of Mycroft's method on certain natural classes of programs. Finally, the techniques developed in this paper provide a general principle for establishing similar results for other analysis methods such as those based on abstract interpretation. As a demonstration of the generality of our technique, we give a characterization theorem for another variation of Mycroft's method called dd-analysis.