ppxscal/embedding_network huggingface dataset:
Diagonal Dominance in the Parallel Partition Method forTridiagonal Systems
Authors: Chris H. Walshaw
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

The partition method for the parallel solution of tridiagonal linear systems is discussed and the coefficients of the reduced global system derived. It is shown that if the full system is diagonally dominant then the reduced system retains this property. This has important implications for the stability of calculations in this reduced system and eliminates the need for global pivoting with its expensive communication overhead.
Computer graphics education in the Czech Republic
Authors: Pavel Slavik
Venue: ACM SIGGRAPH Computer Graphics (1996)

Four years ago I wrote an article about the state of the art in the field of computer graphics education in the former Czechoslovakia. This article was published in Computer Graphics January 1992. Perhaps the most important statement in this article was the fact that computer graphics has a long tradition in this country. In the final section of this article some future plans and goals that we wanted to achieve were stated. Four years is a period of time long enough to evaluate the results achieved. The following text is information about recent developments in the Czech Republic in the field of computer graphics.
The power and performance of proof animation
Authors: Nancy J. Earle, James O. Henriksen
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The Proof Animation 2.1 product family provides our customers with the tools for animating a vast array of applications. There is a version of Proof Animation to meet any need, from small and mid-sized projects to large scale applications. This product family runs on readily available, inexpensive PC hardware without the need for special hardware. Proof Animation is ASCII file-driven and features a general purpose design. Its vector-based geometry provides a large animation canvas with the ability to zoom in or out while maintaining crisp, clear images. Proof Animation's features include post-processing for maximum performance, built-in drawing tools and CAD import/export for ease of creating animation layouts, dynamic bar graphs and plots used for displaying statistics, a multi-windowing display, and a unique presentation-making capability. Because of its open architecture, Proof Animation can serve as the animation tool for models written in a wide variety of simulation and programming languages while remaining easy to use. Proof Animation's user interface is menu-based and can be accessed using either a mouse or keyboard. Its superior power and performance assures smooth, realistic motion for animations regardless of the size, complexity, or application.
APL, dynamic programming, and the optimal control of electromagnetic brake retarders
Authors: Scott Kimbrough
Venue: ACM SIGAPL APL Quote Quad (1995)

The basis of dynamic programming is described. It is a method for finding the best way to control a system when that system can be controlled by its inputs. As an example, the optimal (or best) control of an electromagnetic brake retarder is derived. In this example the current to the brake retarder is the input being controlled. APL is shown to be a convenient language for writing a dynamic programming algorithm. A set of APL subroutines is provided for solving two-dimensional problems with one input. Adept APL programmers may enjoy the challenge of generalizing this code to problems of arbitrary dimensions.
Inductive, coinductive, and pointed types
Authors: Brian T. Howard
Venue: ACM SIGPLAN Notices (1996)

An extension of the simply-typed lambda calculus is presented which contains both well-structured inductive and coinductive types, and which also identifies a class of types for which general recursion is possible. The motivations for this work are certain natural constructions in category theory, in particular the notion of an algebraically bounded functor, due to Freyd. We propose that this is a particularly elegant core language in which to work with recursive objects, since the potential for general recursion is contained in a single operator which interacts well with the facilities for bounded iteration and coiteration.
A Strain Energy Approach to Regularization in Displacement Field Fits of Elastically Deforming Bodies
Authors: Daniel K. Bogen, David A. Rahdert
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

Current methods for regularizing displacement fields in deformation-fitting problems are sensitive to rotation. We propose a rotation-insensitive regularization functional which is the true strain energy for a rubberlike material. The deformation-fitting problem is solved iteratively using successive approximations of the body's rotation, which may be nonuniform.
Incremental maintenance of views with duplicates
Authors: Timothy Griffin, Leonid Libkin
Venue: Proceedings of the 1995 ACM SIGMOD international conference on Management of data (1995)

We study the problem of efficient maintenance of materialized views that may contain duplicates. This problem is particularly important when queries against such views involve aggregate functions, which need duplicates to produce correct results. Unlike most work on the view maintenance problem that is based on an algorithmic approach, our approach is algebraic and based on equational reasoning. This approach has a number of advantages: it is robust and easily extendible to new language constructs, it produces output that can be used by query optimizers, and it simplifies correctness proofs.We use a natural extension of the relational algebra operations to bags (multisets) as our basic language. We present an algorithm that propagates changes from base relations to materialized views. This algorithm is based on reasoning about equivalence of bag-valued expressions. We prove that it is correct and preserves a certain notion of minimality that ensures that no unnecessary tuples are computed. Although it is generally only a heuristic that computing changes to the view rather than recomputing the view from scratch is more efficient, we prove results saying that under normal circumstances one should expect, the change propagation algorithm to be significantly faster and more space efficient than complete recomputing of the view. We also show that our approach interacts nicely with aggregate functions, allowing their correct evaluation on views that change.
Achieving a full deck
Authors: H. K. Hodge
Venue: ACM SIGNUM Newsletter (1995)

While in the process of computing poker odds, the following question occurred to me: given a random number generator that returns answers from one to 52, how many calls on average need to be made before at least one of each number is found?
Prefix Computations on a Generalized Mesh-Connected Computer with Multiple Buses
Authors: Kuo-Liang Chung
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

The mesh-connected computer with multiple buses (MCCMB) is a well-known parallel organization, providing broadcast facilities in each row and each column. In this paper, we propose a 2-D generalized MCCMB (2-GMCCMB) for the purpose of increasing the efficiency of executing some important applications of prefix computations such as solving linear recurrences and tridiagonal systems, etc. A $k_1n_1 \times k_1n_2$ 2-GMCCMB is constructed from a $k_1n_1\times k_1n_2$ mesh organization by enhancing the power of each disjoint $n_1\times n_2$ submesh with multiple buses (sub-2-MCCMB). Given $n$ data, a prefix computation can be performed in $O(n^{1/10})$ time on an $n^{3/5}\times n^{2/5}$ 2-GMCCMB, where each disjoint sub-2-MCCMB is of size $n^{1/2}\times n^{3/10}$. This time bound is faster than the previous time bound of $O(n^{1/8})$ for the same computation on an $n^{5/8}\times n^{3/8}$ 2-MCCMB. Furthermore, the time bound of our parallel prefix algorithm can be further reduced to $O(n^{1/11})$ if fewer processors are used. Our result can be extended to the $d$-dimensional GMCCMB, giving a time bound of $O(n^{1/(d2^d+d)})$ for any constant $d$; here, we omit the constant factors. This time bound is less than the previous time bound of $O(n^{1/(d2^d)})$ on the $d$-dimensional MCCMB.Index Terms¿Broadcasting, mesh-connected computers, mesh-connected computers with multiple buses, parallel algorithms, prefix computation, rectangular meshes.
Data management research at the MITRE Corporation
Authors: Arnon Rosenthal, Len Seligman, Catherine McCollum, Barbara Blaustein, Bhavani Thuraisingham, Edward Lafferty
Venue: ACM SIGMOD Record (1995)

The MITRE Corporation provides technical assistance, system engineering, and acquisition support to large organizations, especially U.S. Government agencies. We help our customers to plan complex systems based on emerging technologies, and to implement systems based on commercial-off-the-shelf products. In MITRE's research program, instead of emphasizing concerns of DBMS or CASE vendors, our research emphasizes the issues of organizations who need to use such products. For example, we favor areas where we can build over commercial products, rather than changing their internals.Data management at MITRE goes beyond research, to include technology transition, system engineering, product evaluation, prototypes, tutorials, advice on customers' strategic directions, and participation in standards efforts. We use prototyping to illustrate potential improvements in customer systems, to understand vendors' capabilities, or both. There are close connections with efforts in object management, real-time systems, reengineering, artificial intelligence, and security.This paper emphasizes the research efforts, grouped into five major themes: information integration, security and privacy, active and responsive systems, metrics, and digital libraries. For each theme, we list the major questions being explored, and identify projects and contacts for further information.
The reuse of uses in Smalltalk programming
Authors: Mary Beth Rosson, John M. Carroll
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (1996)

Software reuse, a long-standing and refractory issue in software technology, has been specifically emphasized as an advantage of the object-oriented programming paradigm. We report an empirical study of expert Smalltalk programmers reusing user interface classes in small graphical applications. Our primary goal was to develop a qualitative characterization of expert reuse strategies that could be used to identify requirements for teaching and supporting reuse programming. A secondary interest was to demonstrate to these experts the Reuse View Matcher&mdash;a prototype reuse tool&mdash;and to collect some initial observations of this tool in use during reuse programming. We observed extensive &ldquo;reuse of uses&rdquo; in the programmers' work: they relied heavily on code in expample applications that provided an implicit specification for reuse of the target class. We called this implicit specification a &ldquo;usage context.&rdquo; The programmers searched for relevant usage contexts early. They repeatedly evaluated the contextualized information to develop solution plans, and they borrowed and adapted it when the sample context suited their immediate reuse goals. The process of code development was highly dynamic and incremental; analysis and implementation were tightly interleaved, frequently driven by testing and debugging. These results are considered in terms of the tradeoffs that inhere in the reuse of uses and the teaching and tool support that might improve the efficiency and accuracy of this approach to reuse.
Instruction fetching: coping with code bloat
Authors: Richard Uhlig, David Nagle, Trevor Mudge, Stuart Sechrest, Joel Emer
Venue: Proceedings of the 22nd annual international symposium on Computer architecture (1995)

Previous research has shown that the SPEC benchmarks achieve low miss ratios in relatively small instruction caches. This paper presents evidence that current software-development practices produce applications that exhibit substantially higher instruction-cache miss ratios than do the SPEC benchmarks. To represent these trends, we have assembled a collection of applications, called the Instruction Benchmark Suite (IBS), that provides a better test of instruction-cache performance. We discuss the rationale behind the design of IBS and characterize its behavior relative to the SPEC benchmark suite. Our analysis is based on trace-driven and trap-driven simulations and takes into full account both the application and operating-system components of the workloads.This paper then reexamines a collection of previously-proposed hardware mechanisms for improving instruction-fetch performance in the context of the IBS workloads. We study the impact of cache organization, transfer bandwidth, prefetching, and pipelined memory systems on machines that rely on the use of relatively small primary instruction caches to facilitate increased clock rates. We find that, although of little use for SPEC, the right combination of these techniques substantially benefits IBS. Even so, under IBS, a stubborn lower bound on the instruction-fetch CPI remains as an obstacle to improving overall processor performance.
Embedding of Complete Binary Trees into Meshes with Row-Column Routing
Authors: Sang-Kyu Lee, Hyeong-Ah Choi
Venue: IEEE Transactions on Parallel and Distributed Systems (1996)

This paper considers the problem of embedding complete binary trees into meshes using the row-column routing and obtained the following results: a complete binary tree with 2p¿ 1 nodes can be embedded 1) with link congestion one into a ${9 \over 8}\sqrt{2^p}\times {9 \over 8}\sqrt{2^p}$ mesh when p is even and a $\sqrt{{\textstyle{9 \over 8}} {2^p}}\times \sqrt{{\textstyle{9 \over 8}} {2^p}}$ mesh when p is odd, and 2) with link congestion two into a $\sqrt{2^p}\times \sqrt{2^p}$ mesh when p is even, and a $\sqrt{2^{p-1}}\times 2\sqrt{2^{p-1}}$ mesh when p is odd.
The active database management system manifesto: a rulebase of ADBMS features
Authors: Corporate Act-Net Consortium
Venue: ACM SIGMOD Record (1996)

Active database systems have been a hot research topic for quite some years now. However, while &ldquo;active functionality&rdquo; has been claimed for many systems, and notions such as &ldquo;active objects&rdquo; or &ldquo;events&rdquo; are used in many research areas (even beyond database technology), it is not yet clear which functionality a database management system must support in order to be legitimately considered as an active system. In this paper, we attempt to clarify the notion of &ldquo;active database management system&rdquo; as well as the functionality it has to support. We thereby distinguish mandatory features that are needed to qualify as an active database system, and desired features which are nice to have. Finally, we perform a classification of applications of active database systems and identify the requirements for an active database management system in order to be applicable in these application areas.
Techniques for FPGA implementation of video compression systems
Authors: Brian Schoner, John Villasenor, Steve Molloy, Rajeev Jain
Venue: Proceedings of the 1995 ACM third international symposium on Field-programmable gate arrays (1995)

Real-time video compression is a challenging subject for FPGA implementation because it typically has a large computational complexity and requires high data throughput. Previous implementations have used parallel banks of FPGAs or DSPs to meet these requirements. Using design techniques that maximize FPGA utilization, we have implemented two video compression systems, each of which uses a single FPGA. In this first system, algorithmic optimizations are made to create a low-complexity implementation that exploits the in-system programmability of the FPGA. This low-complexity implementation performs well, but is limited to a single compression algorithm. In the second system, the FPGA is augmented with an external, low-complexity, video signal processor (VSP) This combination of ASIC and FPGA is flexible enough to implement four common compression algorithms, and powerful enough to execute them in real time.
Simulation programming languages: an abridged history
Authors: Richard E. Nance
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Knowing history can be protective; we have all heard that those who do not are doomed to repeat it. Considering one well regarded expert's estimate of 137 simulation programming languages (SPLs) created by 1981, many perhaps have already duplicated the numerous mistakes of their predecessors. History can also be informative, instructive and entertaining as hopefully this abridged and differently focused approach can illustrate. Questions concerning the causes for so many SPLs, the remarkably similar parallel developments, and the role of the SPLs versus programming languages in general might admit to historical answers. At the least, sharing speculations could prove enlightening and amusing.
Transaction chopping: algorithms and performance studies
Authors: Dennis Shasha, Francois Llirbat, Eric Simon, Patrick Valduriez
Venue: ACM Transactions on Database Systems (TODS) (1995)

Chopping transactions into pieces is good for performance but may lead to nonserializable executions. Many researchers have reacted to this fact by either inventing new concurrency-control mechanisms, weakening serializability, or both. We adopt a different approach. We assume a user who&mdash;has access only to user-level tools such as (1) choosing isolation degrees 1ndash;4, (2) the ability to execute a portion of a transaction using multiversion read consistency, and (3) the ability to reorder the instructions in transaction programs; and &mdash;knows the set of transactions that may run during a certain interval (users are likely to have such knowledge for on-line or real-time transactional applications).Given this information, our algorithm finds the finest chopping of a set of transactions TranSet with the following property: If the pieces of the chopping execute serializably, then TranSet executes serializably. This permits users to obtain more concurrency while preserving correctness. Besides obtaining more intertransaction concurrency, chopping transactions in this way can enhance intratransaction parallelism.The algorithm is inexpensive, running in O(n&times;(e+m)) time, once conflicts are identified, using a naive implementation, where n is the number of concurrent transactions in the interval, e is the number of edges in the conflict graph among the transactions, and m is the maximum number of accesses of any transaction. This makes it feasible to add as a tuning knob to real systems.
Next cache line and set prediction
Authors: Brad Calder, Dirk Grunwald
Venue: Proceedings of the 22nd annual international symposium on Computer architecture (1995)

Accurate instruction fetch and branch prediction is increasingly important on today's wide-issue architectures. Fetch prediction is the process of determining the next instruction to request from the memory subsystem. Branch prediction is the process of predicting the likely out-come of branch instructions. Several researchers have proposed very effective fetch and branch prediction mechanisms including branch target buffers (BTB) that store the target addresses of taken branches. An alternative approach fetches the instruction following a branch by using an index into the cache instead of a branch target address. We call such an index a next cache line and set (NLS) predictor. A NLS predictor is a pointer into the instruction cache, indicating the target instruction of a branch.In this paper we examine the use of NLS predictors for efficient and accurate fetch and branch prediction. Previous studies associated each NLS predictor with a cache line and provided only one-bit conditional branch predictors. Our study examines the use of NLS predictors with highly accurate two-level correlated conditional branch architectures. We examine the performance of decoupling the NLS predictors from the cache line and storing them in a separate tag-less memory buffer. Our results show that the decoupled architecture performs better than associating the NLS predictors with the cache line, that the NLS architecture benefits from reduced cache miss rates, and it is particularly effective for programs containing many branches. We also provide an in-depth comparison between the NLS and BTB architectures, showing that the NLS architecture is a competitive alternative to the BTB design.
Industrial strength simulation using GPSS/H
Authors: Robert C. Crain, Douglas S. Smith
Venue: Proceedings of the 27th conference on Winter simulation (1995)

GPSS/H is a tried-and-true simulation tool whose user base, both commercial and academic, continues to grow despite the presence of so many "new" simulation technology trends. The process-interaction world view combines with the advanced features available in GPSS/H to make it one of the most powerful and flexible tools available, capable of handling the largest simulation projects with ease. In the following sections, we provide an overview of GPSS/H and its process-interaction world view. We then discuss model-building interfaces and the advantages and pitfalls of graphical modeling environments. Advanced and newly-added features of GPSS/H Release 3 are detailed. Then we describe the special-purpose simulator and features of GPSS/H which make it ideal for use as a simulator engine, including a summary of the recent developments in the run-time product line.
Twisted Extensions of Spin Models
Authors: K. Nomura
Venue: Journal of Algebraic Combinatorics: An International Journal (1995)

A spin model is one of the statistical mechanical models which were introduced by V.F.R. Jones to construct invariants of links. In this paper, we give a new construction of spin models of size 4n from a given spin model of size n. The process is similar to taking tensor product with a spin model of size four, but we add some sign exchange. This construction also gives symmetric four-weight spin models of the type introduced by E. Bannai and E. Bannai.