ppxscal/embedding_network huggingface dataset:
Reducing Data Hazards on Multi-pipelined DSP Architecture with Loop Scheduling
Authors: Sissades Tongsima, Chantana Chantrapornchai, Edwin H.-M. Sha, Nelson L. Passos
Venue: Journal of VLSI Signal Processing Systems (1998)

Computation intensive DSP applications usually require parallel/pipelined processors in order to meet specific timing requirements. Data hazards are a major obstacle against the high performance of pipelined systems. This paper presents a novel efficient loop scheduling algorithm that reduces data hazards for such DSP applications. This algorithm has been embedded in a tool, called SHARP, which schedules a pipelined data flow graph to multiple pipelined units while hiding the underlying data hazards and minimizing the execution time. This paper reports significant improvement for some well-known benchmarks showing the efficiency of the scheduling algorithm and the flexibility of the simulation tool.
On Approximate Solutions in Convex Vector Optimization
Authors: Sien Deng
Venue: SIAM Journal on Control and Optimization (1997)

Necessary and sufficient conditions are obtained for the existence of $\epsilon$-weak minima for constrained convex vector optimization problems. The characterization of $\epsilon$-weak minima is given in terms of $\epsilon$-optimal solutions of the associated scalar optimization problems and $\epsilon$-directional derivatives of objective functions. The Lipschitzian continuity of $\epsilon$-weak minima is proved under mild conditions.
A generic simulator for modeling manufacturing modules
Authors: Bernard J. Schroer, Phillip A. Farrington, James J. Swain, Dawn R. Utley
Venue: Proceedings of the 28th conference on Winter simulation (1996)

This paper presents a simulator for designing and analyzing modular manufacturing lines. Included in this paper are a description of the simulator, a sample application, and the benefits of using this approach.
Analysis of Augmented Krylov Subspace Methods
Authors: Yousef Saad
Venue: SIAM Journal on Matrix Analysis and Applications (1997)

Residual norm estimates are derived for a general class of methods based on projection techniques on subspaces of the form $ K_m + {\cal W}$, where $K_m$ is the standard Krylov subspace associated with the original linear system and ${\cal W}$ is some other subspace. These "augmented Krylov subspace methods" include eigenvalue deflation techniques as well as block-Krylov methods. Residual bounds are established which suggest a convergence rate similar to one obtained by removing the components of the initial residual vector associated with the eigenvalues closest to zero. Both the symmetric and nonsymmetric cases are analyzed.
Ray Shooting Amidst Spheres in Three Dimensions and Related Problems
Authors: Shai Mohaban, Micha Sharir
Venue: SIAM Journal on Computing (1997)

We consider the problem of ray shooting amidst spheres in 3-space: given n arbitrary (possibly intersecting) spheres in 3-space and any $\epsilon$ > 0, we show how to preprocess the spheres in time $O(n^{3+\epsilon})$ into a data structure of size $O(n^{3+\epsilon})$ so that any ray-shooting query can be answered in time $O(n^\epsilon)$. Our result improves previous techniques (see [P. K. Aggarwal, L. Guibas, M. Pellegrini, and M. Sharir, "Ray shooting amidst spheres," unpublished note] and [P. K. Aggarwal and J. Matousek, Discrete Comput. Geom., 11 (1994), pp. 393-418]), where roughly $O(n^4)$ storage was required to support fast queries. Our result shows that ray shooting amidst spheres has complexity comparable with that of ray shooting amidst planes in 3-space. Our technique applies to more general (convex) objects in 3-space, and we also discuss those extensions.
Multilevel hypergraph partitioning: application in VLSI domain
Authors: George Karypis, Rajat Aggarwal, Vipin Kumar, Shashi Shekhar
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

In this paper, we present a new hypergraph partitioning algorithmthat is based on the multilevel paradigm. In the multilevel paradigm,a sequence of successively coarser hypergraphs is constructed. Abisection of the smallest hypergraph is computed and it is used toobtain a bisection of the original hypergraph by successively projectingand refining the bisection to the next level finer hypergraph.We evaluate the performance both in terms of the size of the hyper-edgecut on the bisection as well as run time on a number of VLSIcircuits. Our experiments show that our multilevel hypergraph partitioningalgorithm produces high quality partitioning in relativelysmall amount of time. The quality of the partitionings produced byour scheme are on the average 4% to 23% better than those producedby other state-of-the-art schemes. Furthermore, our partitioning algorithmissignificantly faster, often requiring 4 to 15 times less timethan that required by the other schemes. Our multilevel hypergraphpartitioning algorithm scales very well for large hypergraphs. Hypergraphswith over 100,000 vertices can be bisected in a few minuteson today's workstations. Also, on the large hypergraphs, ourscheme outperforms other schemes (in hyperedge cut) quite consistentlywith larger margins (9% to 30%).
The constrained via minimization problem for PCB and VLSI design
Authors: Xiao-Ming Xiong, Ernest S. Kuh
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

A new via minimization approach is presented for two layer routing of printed circuit boards and VLSI chips. We have analyzed and characterized different aspects of the problem and have derived an equivalent graph model for the problem from the linear programming formulation. Based on the analysis of our unified formulation, we posed a practical heuristic algorithm. The algorithm can handle both grid-based and gridless routing. Also, an arbitrary number of wires is allowed to intersect at a via and we allow both Manhattan and knock-knee routings.
Simulation in policy analysis: the transfer of facilities within the Department of Energy's Environmental Management program
Authors: Samuel M. Hart
Venue: Proceedings of the 28th conference on Winter simulation (1996)

This paper explains how process simulation can be applied as a policy analysis tool. While many simulations are used to evaluate and improve specific processes, few are currently used as a policy analysis or decision-making tool. For the purpose of choosing from several potential policy choices, a simulation model can describe the probable outcomes under each alternative in a concise and easily understood manner. Such a model can combine the work of several more traditional policy analysis tools into a single analysis that, once designed, can be performed in a fraction of the time. The specific case presented in this paper is the transfer of deactivated facilities from one organization (the Office of Nuclear Material and Facility Stabilization) to another (the Office of Environmental Restoration) within the Department of Energy's Environmental Management program. The model was developed using VENSIM, an off-the-shelf modeling software package. With the completed model, several potential policy choices regarding the rate of facility transfer were assessed to identify funding and scheduling problems with each policy.
Quasi-cubes: exploiting approximations in multidimensional databases
Authors: Daniel Barbará, Mark Sullivan
Venue: ACM SIGMOD Record (1997)

A data cube is a popular organization for summary data. A cube is simply a multidimensional structure that contains at each point an aggregate value, i.e., the result of applying an aggregate function to an underlying relation. In practical situations, cubes can require a large amount of storage. The typical approach to reducing storage cost is to materialize parts of the cube on demand. Unfortunately, this lazy evaluation can be a time-consuming operation. In this paper, we describe an approximation technique that reduces the storage cost of the cube without incurring the run time cost of lazy evaluation. The idea is to provide an incomplete description of the cube and a method of estimating the missing entries with a certain level of accuracy. The description, of course, should take a fraction of the space of the full cube and the estimation procedure should be faster than computing the data from the underlying relations. Since cubes are used to support data analysis and analysts are rarely interested in the precise values of the aggregates (but rather in trends), providing approximate answers is, in most cases, a satisfactory compromise. Alternatively, the technique can be used to implement a multiresolution system in which a tradeoff is established between the execution time of queries and the errors the user is willing to tolerate. By only going to the disk when it is necessary (to reduce the errors), the query can be executed faster. This idea can be extended to produce a system that incrementally increases the accuracy of the answer while the user is looking at it, supporting on-line aggregation.
Formal verification of the Sobel image processing chip
Authors: Paliath Narendran, Jonathan Stillman
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

We describe an approach to hardware verification in the context of our recent success in formally verifying the description of an image processing chip currently under development at Research Triangle Institute. We demonstrate that our approach, which uses an implementation of an equational approach to theorem proving developed by Kapur and Narendran, can be a viable alternative to simulation. In particular, we are able to take advantage of the &ldquo;recursive&rdquo; nature of many circuits, such as n-bit adders, and our techniques allow verification of sequential circuits. To the best of our knowledge this is the first, time a complex sequential circuit which was not designed with formal verification specifically in mind has been verified. Finally, we describe the discovery of several design errors in the circuit description, detected during the verification attempt (the actual verification could only take place once these errors were removed), and discuss directions that future work will take. A significantly more detailed description of this work can be found in [NaSt 881].
A combined unifrontal/multifrontal method for unsymmetric sparse matrices
Authors: Timothy A. Davis, Iain S. Duff
Venue: ACM Transactions on Mathematical Software (TOMS) (1999)

We discuss the organization of frontal matrices in multifrontal methods for the solution of large sparse sets of unsymmetric linear equations. In the multifrontal method, work on a frontal matrix can be suspended, the frontal matrix can be stored for later reuse, and a new frontal matrix can be generated. There are thus several frontal matrices stored during the factorization, and one or more of these are assembled (summed) when creating a new frontal matrix. Although this means that arbitrary sparsity patterns can be handled efficiently, extra work is required to sum the frontal matrices together and can be costly because indirect addressing is requred. The (uni)frontal method avoids this extra work by factorizing the matrix with a single frontal matrix. Rows and columns are added to the frontal matrix, and pivot rows and columns are removed. Data movement is simpler, but higher fill-in can result if the matrix cannot be permuted into a variable-band form with small profile. We consider a combined unifrontal/multifrontal algorithm to enable general fill-in reduction orderings to be applied without the data movement of previous multifrontal approaches. We discuss this technique in the context of a code designed for the solution of sparse systems with unsymmetric pattern.
Extension of standardized time series for continuous-time statistics
Authors: Ardavan Nozari
Venue: Proceedings of the 17th conference on Winter simulation (1985)

In steady-state computer simulation experiments continuous-time statistics play an important role. They are used to estimate a variety of different system's parameters. For example, in queueing simulations continuous-time statistics are used to estimate expected number of customers in the system, expected utilization of the server, and the expected departure rate of customers, among others. In steady-state simulation experiments we typically observe two types of continuous-time statistics: A stationary stochastic process y(t), 0&le;t&le;T, such that E[y(t)] = &mgr;, 0&le;t&le;T. A stationary increment jump process y(t), 0&le;t&le;T such that E[y(t)/t] = &mgr;, 0<t&le;T, and y(0) = 0. The objective of the experiment is typically to estimate an interval, I, which with a prespecified probability &eegr; contains &mgr;, i.e., Pr{&mgr;&egr;I} = &eegr;. The interval I is referred to as a confidence interval and is denoted by &plusmn; &mgr; H, where &mgr; is the center and H is the half-width of the interval. For the above cases, &mgr; is respectively computed by: &mgr; = T-1 &mgr;T0 y(t)dt. &mgr; = T-1 y(T). In this talk we present formulas for estimating H for each of the above cases. These formulas are developed and evaluated in Nozari [1]. The formulas are extensions of the method of &ldquo;Standardized Time Series&rdquo; developed by Schruben [2] for discrete-time observations. We give formulas for two different estimators: Area, which is the continuous-time version of the Sum estimator of Schruben, and Maximum. Also, we give formulas for combining these estimators with the classical estimator. To examine the behavior of the estimators, we present results of a Monte Carlo study. Our estimators work quite well and our results are consistent with those of Schruben for discrete-time observations.
Perfect Secret Sharing Schemes on Five Participants
Authors: Wen-Ai Jackson, Keith M. Martin
Venue: Designs, Codes and Cryptography (1996)

A perfect secret sharing scheme is a system for the protection of a secret among a number of participants in such a way that only certain subsets of these participants can reconstruct the secret, and the remaining subsets can obtain no additional information about the secret. The efficiency of a perfect secret sharing scheme can be assessed in terms of its information rates. In this paper we discuss techniques for obtaining bounds on the information rates of perfect secret sharing schemes and illustrate these techniques using the set of monotone access structures on five participants. We give a full listing of the known informtion rate bounds for all the monotone access structures on five participants.
Capabilities-Based Query Rewriting in Mediator Systems
Authors: Yannis Papakonstantinou, Ashish Gupta, Laura Haas
Venue: Distributed and Parallel Databases (1998)

Users today are struggling to integrate a broad range of information sources providing different levels of query capabilities. Currently, data sources with different and limited capabilities are accessed either by writing rich functional wrappers for the more primitive sources, or by dealing with all sources at a &ldquo;lowest common denominator&rdquo;. This paper explores a third approach, in which a mediator ensures that sources receive queries they can handle, while still taking advantage of all of the query power of the source. We propose an architecture that enables this, and identify a key component of that architecture, the Capabilities-Based Rewriter (CBR). The CBR takes as input a description of the capabilities of a data source, and a query targeted for that data source. From these, the CBR determines component queries to be sent to the sources, commensurate with their abilities, and computes a plan for combining their results using joins, unions, selections, and projections. We provide a language to describe the query capability of data sources and a plan generation algorithm. Our description language and plan generation algorithm are schema independent and handle SPJ queries. We also extend CBR with a cost-based optimizer. The net effect is that we prune without losing completeness. Finally we compare the implementation of a CBR for the Garlic project with the algorithms proposed in this paper.
Hierarchical sequence compaction for power estimation
Authors: Radu Marculescu, Diana Marculescu Massoud Pedram
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

This paper presents an effective technique forcompacting a large sequence of input vectors into a muchsmaller one such that when the two sequences are applied toany circuit, the resulting power dissipations are nearly thesame. Specifically, this paper introduces the hierarchicalmodeling of Markov chains as a flexible framework forcapturing not only complex spatiotemporal correlations, butalso dynamic changes in the characteristics of the inputsequence. The new framework has a high degree ofadaptability, i.e. the hierarchical model is dynamically grownaccording to the sequence behavior. Experimental resultsdemonstrate that large compaction ratios can be obtainedwithout a significant loss in accuracy (less than 5% on average)of power estimates.
Separators for sphere-packings and nearest neighbor graphs
Authors: Gary L. Miller, Shang-Hua Teng, William Thurston, Stephen A. Vavasis
Venue: Journal of the ACM (JACM) (1997)

A collection of n balls in d dimensions forms a k-ply system if no point in the space is covered by more than k balls. We show that for every k-ply system &Ggr;, there is a sphere S that intersects at most O(k1/dn1&minus;1/d) balls of &Ggr; and divides the remainder of &Ggr; into two parts: those in the interior and those in the exterior of the sphere S, respectively, so that the larger part contains at most (1&minus;1/(d+2))n balls. This bound of (O(k1/dn1&minus;1/d) is the best possible in both n and k. We also present a simple randomized algorithm to find such a sphere in O(n) time. Our result implies that every k-nearest neighbor graphs of n points in d dimensions has a separator of size O(k1/dn1&minus;1/d). In conjunction with a result of Koebe that every triangulated planar graph is isomorphic to the intersection graph of a disk-packing, our result not only gives a new geometric proof of the planar separator theorem of Lipton and Tarjan, but also generalizes it to higher dimensions. The separator algorithm can be used for point location and geometric divide and conquer in a fixed dimensional space.
&ldquo;Who cares about elegance?&rdquo; The role of aesthetics in programming language design
Authors: Bruce J. MacLennan
Venue: ACM SIGPLAN Notices (1997)

The crucial role played by aesthetics in programming language design and the importance of elegance in programming languages are defended on the basis of analogies with structural engineering, as presented in Billington's The Tower and the Bridge.
SYMCAD: synthesis of microprogrammed control for automated VLSI design
Authors: B. L. Priyadarshan, M. Balakrishnan, Anshul Kumar, G. S. Visweswaran
Venue: Proceedings of the 23rd annual workshop and symposium on Microprogramming and microarchitecture (1990)

This paper discusses a software package named SYMCAD, a retargetable microcode synthesizer which forms part of a microprogrammed control synthesis in the VLSI CAD system IDEAS (Integrated Design Automation System) [1]. The objective is to synthesize a microprogrammed control for a specified data part and microsequencer to realize the behavior expressed in a hardware description language. A distinctive feature of this approach is the synthesis of a customized control unit suitable for VLSI realization. Retargetable microcode generation comprises symbolic microprogram synthesis, microinstruction format generation and binary microcode generation, to map the required behavior on the specified micro-architecture.
A graph compaction approach to fault simulation
Authors: Dov Harel, Balakrishnan Krishnamurthy
Venue: Proceedings of the 25th ACM/IEEE Design Automation Conference (1988)

We describe a graph compaction based algorithm for fault simulation in combinational circuits. The algorithm consists of reducing the circuit graph by repeatedly removing non-reconvergent vertices. The algorithm have been implemented in Smalltalk and preliminary experimental results are presented. A version of the algorithm outperforms all known fault simulation algorithms on a family of hard circuits.
What is Computational Economics?
Authors: Hans M. Amman
Venue: Computational Economics (1997)

Computational Economics is rapidly evolving into an independent branche in economics. This paper describes the current and future developments within the field of Computational Economics.
IGTree: Using Trees for Compression and Classification in Lazy LearningAlgorithms
Authors: Walter Daelemans, Antal Van Den Bosch, Ton Weijters
Venue: Artificial Intelligence Review (1997)

We describe the IGTree learning algorithm, which compresses an instance base into a tree structure. The concept of information gain is used as a heuristic function for performing this compression. IGTree produces trees that, compared to other lazy learning approaches, reduce storage requirements and the time required to compute classifications. Furthermore, we obtained similar or better generalization accuracy with IGTree when trained on two complex linguistic tasks, viz. letter&ndash;phoneme transliteration and part-of-speech-tagging, when compared to alternative lazy learning and decision tree approaches (viz., IB1, information-gain-weighted IB1, and C4.5). A third experiment, with the task of word hyphenation, demonstrates that when the mutual differences in information gain of features is too small, IGTree as well as information-gain-weighted IB1 perform worse than IB1. These results indicate that IGTree is a useful algorithm for problems characterized by the availability of a large number of training instances described by symbolic features with sufficiently differing information gain values.
Finite Element Approximation of The Transport of Reactive Solutes in Porous Media. Part II: Error Estimates for Equilibrium Adsorption Processes
Authors: John W. Barrett, Peter Knabner
Venue: SIAM Journal on Numerical Analysis (1997)

In this paper we analyze a fully practical piecewise linear finite element approximation involving numerical integration, backward Euler time discretization, and possibly regularization and relaxation of the following degenerate parabolic equation arising in a model of reactive solute transport in porous media: find $u(x,t)$ such that $$ \partial_t u + \partial_t [ \p (u)] - \Delta u = f \quad {\rm in} \quad \Omega \times (0,T\,], $$ \vspace*{-12pt} $$ u = 0 \quad {\rm on} \quad \partial \Omega \times (0,T\,] \qquad u(\cdot ,0) = g(\cdot ) \quad {\rm in} \; \Omega $$ for known data $ \Omega \subset {\bf R}^d, \; 1 \leq d \leq 3 $, $f$, $g$, and a monotonically increasing $ \p \in {\rm C}^0({\bf R}) \cap {\rm C}^1(- \infty , 0] \cup (0,\infty)$ satisfying $ \p (0) = 0$, which is only locally H&ouml;lder continuous with exponent $ p \in (0,1)$ at the origin; e.g., $ \p (s) \equiv [s]_+^p $. This lack of Lipschitz continuity at the origin limits the regularity of the unique solution $u$ and leads to difficulties in the finite element error analysis.