ppxscal/embedding_network huggingface dataset:
Centaur: the system
Authors: P. Borras, D. Clement, Th. Despeyroux, J. Incerpi, G. Kahn, B. Lang, V. Pascual
Venue: Proceedings of the third ACM SIGSOFT/SIGPLAN software engineering symposium on Practical software development environments (1989)

This paper describes the organization of the CENTAUR system and its main components. The system is a generic interactive environment. When given the formal specification of a particular programming language-including syntax and semantics &mdash; it produces a language specific environment. This resulting environment includes a structure editor, an interpreter/debugger and other tools, all of which have graphic interfaces. CENTAUR is made of three parts: a database component, that provides standardized representation and access to formal objects and their persistent storage; a logical engine that is used to execute formal specifications; an object-oriented man-machine interface that gives easy access to the system's functions. CENTAUR is essentially written in Lisp (Le_Lisp). The logical engine is Prolog (Mu-Prolog). The man-machine interface is built on top of the virtual graphics facility of Le_Lisp, itself primarily implemented on top of X-Windows.
Interviews with Edward Teller and Eugene P. Wigner
Authors: J. R. Brink, C. R. Haden
Venue: IEEE Annals of the History of Computing (1989)

No abstract available.
A Systolic Accelerator for the Iterative Solution of Sparse Linear Systems
Authors: R. Melhem
Venue: IEEE Transactions on Computers (1989)

The idea of grouping the nonzero elements of a sparse matrix into a few stripes that are almost parallel is applied to the design of a systolic accelerator for sparse matrix operations. This accelerator is then integrated into a complete systolic system for the solution of large sparse linear systems of equations. The design demonstrates that the application of systolic arrays is not limited to regular computations, and that computationally irregular problems can be solved on systolic networks if local storage is provided in each systolic cell for buffering the irregularity in the data movement and for absorbing the irregularity in the computation.
Improving register allocation for subscripted variables
Authors: David Callahan, Steve Carr, Ken Kennedy
Venue: ACM SIGPLAN Notices (1990)

Most conventional compilers fail to allocate array elements to registers because standard data-flow analysis treats arrays like scalars, making it impossible to analyze the definitions and uses of individual array elements. This deficiency is particularly troublesome for floating-point registers, which are most often used as temporary repositories for subscripted variables. In this paper, we present a source-to-source transformation, called scalar replacement, that finds opportunities for reuse of subscripted variables and replaces the references involved by references to temporary scalar variables. The objective is to increase the likelihood that these elements will be assigned to registers by the coloring-based register allocators found in most compilers. In addition, we present transformations to improve the overall effectiveness of scalar replacement and show how these transformations can be applied in a variety of loop nest types. Finally, we present experimental results showing that these techniques are extremely effective&mdash;capable of achieving integer factor speedups over code generated by good optimizing compilers of conventional design.
Techniques for Calibration of the Scale Factor and Image Center for High Accuracy 3-D Machine Vision Metrology
Authors: R. K. Lenz, R. Y. Tsai
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

Techniques are described for calibrating certain intrinsic camera parameters for machine vision. The parameters to be calibrated are the horizontal scale factor, and the image center. The scale factor calibration uses a one-dimensional fast Fourier transform and is accurate and efficient. It also permits the use of only one coplanar set of calibration points for general camera calibration. Three groups of techniques for center calibration are presented: Group I requires using a laser and a four-degree-of-freedom adjustment of its orientation, but is simplest in concept and is accurate and reproducible; Group II is simple to perform, but is less accurate than the other two; and the most general, Group II, is accurate and efficient, but requires a good calibration plate and accurate image feature extraction of calibration points. Group II is recommended most highly for machine vision applications. Results of experiments are presented and compared with theoretical predictions. Accuracy and reproducibility of the calibrated parameters are reported, as well as the improvement in actual 3-D measurement due to center calibration.
Parallel compilation for a parallel machine
Authors: T. Gross, A. Sobel, M. Zolg
Venue: Proceedings of the ACM SIGPLAN 1989 Conference on Programming language design and implementation (1989)

An application for a parallel computer with multiple, independent processors often includes different programs (functions) for the individual processors; compilation of such functions can proceed independently. We implemented a compiler that exploits this parallelism by partitioning the input program for parallel translation. The host system for the parallel compiler is an Ethernet-based network of workstations, and different functions of the application program are compiled in parallel on different workstations. For typical programs in our environment, we observe a speedup ranging from 3 to 6 using not more than 9 processors. The paper includes detailed measurements for this parallel compiler; we report the system overhead, implementation overhead, as well as the speedup obtained when compared with sequential compilation.
Dynamic voting algorithms for maintaining the consistency of a replicated database
Authors: S. Jajodia, David Mutchler
Venue: ACM Transactions on Database Systems (TODS) (1990)

There are several replica control algorithms for managing replicated files in the face of network partitioning due to site or communication link failures. Pessimistic algorithms ensure consistency at the price of reduced availability; they permit at most one (distinguished) partition to process updates at any given time. The best known pessimistic algorithm, voting, is a &ldquo;static&rdquo; algorithm, meaning that all potential distinguished partitions can be listed in advance. We present a dynamic extension of voting called dynamic voting. This algorithm permits updates in a partition provided it contains more than half of the up-to-date copies of the replicated file. We also present an extension of dynamic voting called dynamic voting with linearly ordered copies (abbreviated as dynamic-linear). These algorithms are dynamic because the order in which past distinguished partitions were created plays a role in the selection of the next distinguished partition. Our algorithms have all the virtues of ordinary voting, including its simplicity, and provide improved availability as well. We provide two stochastic models to support the latter claim. In the first (site) model, sites may fail but communication links are infallible; in the second (link) model the reverse is true. We prove that under the site model, dynamic-linear has greater availability than any static algorithm, including weighted voting, if there are four or more sites in the network. In the link model, we consider all biconnected five-site networks and a wide variety of failure and repair rates. In all cases considered, dynamic-linear had greater availability than any static algorithm.
Predictability of Process Resource Usage: A Measurement-Based Study on UNIX
Authors: M. V. Devarakonda, R. K. Iyer
Venue: IEEE Transactions on Software Engineering (1989)

A statistical approach is developed for predicting the CPU time, the file I/O, and the memory requirements of a program at the beginning of its life, given the identity of the program. Initially, statistical clustering is used to identify high-density regions of process resource usage. The identified regions form the states for building a state-transition model to characterize the resource usage of each program in its past executions. The prediction scheme uses the knowledge of the program's resource usage in its last execution together with its state-transition model to predict the resource usage in its next execution. The prediction scheme is shown to work using process resource-usage data collected from a VAX 11/780 running 4.3 BSD Unix. The results show that the predicted values correlate strongly with the actual; the coefficient of correlation between the predicted and actual values for CPU time is 0.84. The errors in prediction are mostly small and are heavily skewed toward small values.
The Performance of Parallel Prolog Programs
Authors: Barry S. Fagin, Alvin M. Despain
Venue: IEEE Transactions on Computers (1990)

Performance results are presented for a parallel execution model for Prolog that supports AND-parallelism, OR-parallelism, and intelligent backtracking. The results show that restricted AND-parallelism is of limited benefit for small programs, but produced speedups from 7-10 on two large programs. OR-parallelism was found to be generally not useful for the benchmarks examined if the semantics of Prolog were preserved. Of particular interest is the phenomenon of super-multiplicative behavior, in which the performance improvement obtained when more than one technique is used is greater than the product of the performance improvements due to each technique individually. The implications of the performance results for parallel Prolog systems are discussed, and directions for future work are indicated.
An expert autonomous vacuum cleaner robot
Authors: Goh Wee Lang
Venue: Proceedings of the 1st international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1988)

This paper describes the design of a Prolog-based expert system for real-time control of an autonomous vacuum cleaner robot. The system has been tested on simple navigational problems such as path finding, world mapping and obstacle avoidance. The robot is capable of responding to a dynamically changeing environment in real time as is the case when furniture in a room, for example, is shifted while the robot is in action.
Optimizing Joins in Fragmented Database Systems on a Broadcast Local Network
Authors: Jason S. J. Chen, Victor O. K. Li
Venue: IEEE Transactions on Software Engineering (1989)

The problem of optimizing joins between two fragmented relations on a broadcast local network is analyzed. Data redundancy is considered. Semantic information associated with fragments are used to eliminate necessary processing. More than one physical copies of a fragment is allowed to be used in a strategy to achieve more parallelism. Join-analysis graphs are introduced to represent joins on two fragmented relations. The problem of optimizing a join is mapped into an equivalent problem of finding a minimum-weight vertex cover for the corresponding join-analysis graph. This problem is proved to be NP-hard. A four-phase approach for processing joins is proposed.
Compression of concordances in full-text retrieval systems
Authors: Y. Choueka, A. S. Fraenkel, S. T. Klein
Venue: Proceedings of the 11th annual international ACM SIGIR conference on Research and development in information retrieval (1988)

The concordance of a full-text information retrieval system contains for every different word W of the data base, a list L(W) of &ldquo;coordinates&rdquo;, each of which describes the exact location of an occurrence of W in the text. The concordance should be compressed, not only for the savings in storage space, but also in order to reduce the number of I/O operations, since the file is usually kept in secondary memory. Several methods are presented, which efficiently compress concordances of large fulltext retrieval systems. The methods were tested on the concordance of the Responsa Retrieval Project and yield savings of up to 49% relative to the non-compressed file; this is a relative improvement of about 27% over the currently used prefix-omission compression technique.
Remote operation calls in a heterogeneous environment
Authors: T. Patrick Martin, David T. Barnard, Ian A. Macleod, Brent Nordin, R. Mark Fleming
Venue: Proceedings of the 1988 ACM SIGSMALL/PC symposium on ACTES (1988)

Remote Operation Calls (ROC's) are a mechanism for remote execution in a network of personal computers. This paper describes the implementation of a version of ROC's that function in a heterogeneous environment consisting of a network of personal computers and SUN/UNIX machines.
A decision procedure for conjunctive query disjointness
Authors: C. Elkan
Venue: Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1989)

This paper presents an algorithm that decides whether two conjunctive query expressions always describe disjoint sets of tuples. The decision procedure solves an open problem identified by Blakeley, Coburn, and Larson: how to check whether an explicitly stored view relation must be recomputed after an update, taking into account functional dependencies. For nonconjunctive queries, the disjointness problem is NP-hard. For conjunctive queries, the time complexity of the algorithm given cannot be improved unless the reachability problem for directed graphs can be solved in sublinear time. The algorithm is novel in that it combines separate decision procedures for the theory of functional dependencies and for the theory of dense orders. Also, it uses tableaux that are capable of representing all six comparison operators <, &le;, =, &ge;, >, and &ne;.
Sheaved memory: architectural support for state saving and restoration in pages systems
Authors: M. E. Staknis
Venue: ACM SIGARCH Computer Architecture News (1989)

The concept of read-one/write-many paged memory is introduced and given the name sheaved memory. It is shown that sheaved memory is useful for efficiently maintaining checkpoints in main memory and for providing state saving and state restoration for software that includes recovery blocks or similar control structures. The organization of sheaved memory is described in detail, and a design is presented for a prototype sheaved-memory module that can be built easily from inexpensive, off-the-shelf components. The module can be incorporated within many available computers without altering the computers' hardware design. The concept of sheaved memory is simple and appealing, and its potential for use in a number of software contexts is foreseen.
Flagship: a parallel architecture for declarative programming
Authors: I. Watson, V. Woods, P. Watson, R. Banach, M. Greenberg
Venue: ACM SIGARCH Computer Architecture News (1988)

The Flagship project aims to produce a computing technology based on the declarative style of programming. A major component of that technology is the design for a parallel machine which can efficiently exploit the implicit parallelism in declarative programs. This paper describes the computational models which expose this implicit parallelism, and outlines an architecture designed to exploit it. The operational issues, such as dynamic load balancing, which arise in such a system are discussed, and the mechanisms being used to evaluate the architecture are described.
Context and orientation in hypermedia networks
Authors: Kenneth Utting, Nicole Yankelovich
Venue: ACM Transactions on Information Systems (TOIS) (1989)

The core of hypermedia's power lies in the complex networks of links that can be created within and between documents. However, these networks frequently overwhelm the user and become a source of confusion. Within Intermedia, we have developed the Web View-a tool for viewing and navigating such networks with a minimum of user confusion and disorientation. The key factors in the Web View's success are a display that combines a record of the user's path through the network with a map of the currently available links; a scope line that summarizes the number of documents and links in the network; and a set of commands that permit the user to open documents directly from the Web View.
Pattern match reduction for Relational Production Language in the USL MMDBS
Authors: L. M. L. Delcambre, J. Waramahaputi, J. N. Etheredge
Venue: ACM SIGMOD Record (1989)

The Relational Production Language, RPL, is a rule language where both the condition and action part of a rule is expressed in a relational language. This makes RPL a natural choice for expert database systems. In this paper, the performance of the RPL interpreter is addressed through the use of Pattern Match Reduction, PMR, within the context of the USL main memory database system, the USL MMDBS. PMR provides a generalization of relational view materialization by supporting relationally complete queries and by allowing the materialization of any/all intermediate nodes in a query tree. The USL MMDBS supports PMR because of its performance characteristics for query processing (due to a linear sort/join algorithm) and because intermediate query results are stored as &ldquo;first class&rdquo; relations. Thus the materialization required by PMR is directly supported. This paper introduces PMR and the USL MMDBS and presents preliminary performance results.
Polymorphic-Torus Network
Authors: H. Li, M. Maresca
Venue: IEEE Transactions on Computers (1989)

An interconnection network is presented for a massively parallel fine-grained single-instruction, multiple-data (SIMD) system, called the polymorphic-torus, whose design goal is to provide high communication bandwidth under a packaging constraint. This goal is achieved by the polymorphic principle, which injects switches with circuit-switching capability into every node of a base network (e.g. a two-dimensional torus). The polymorphic approach maintains wiring complexity of the base network but effectively increases the communication bandwidth due to its flexibility in reconfiguring the switches individually and dynamically to match the algorithm graph. Formal analysis on interpackage wiring (the flux) and the intrapackage wiring (the fluid) is given for the polymorphic-torus and the related torus networks. Three algorithms, namely, the Boolean, the max/min, and the sum operations, are developed to illustrate the use of the polymorphic principle in enhancing the communication bandwidth with no penalty of the interpackage wiring complexity.
Index scans using a finite LRU buffer: a validated I/O model
Authors: Lothar F. Mackert, Guy M. Lohman
Venue: ACM Transactions on Database Systems (TODS) (1989)

Indexes are commonly employed to retrieve a portion of a file or to retrieve its records in a particular order. An accurate performance model of indexes is essential to the design, analysis, and tuning of file management and database systems, and particularly to database query optimization. Many previous studies have addressed the problem of estimating the number of disk page fetches when randomly accessing k records out of N given records stored on T disk pages. This paper generalizes these results, relaxing two assumptions that usually do not hold in practice: unlimited buffer and unique records for each key value. Experiments show that the performance of an index scan is very sensitive to buffer size limitations and multiple records per key value. A model for these more practical situations is presented and a formula derived for estimating the performance of an index scan. We also give a closed-form approximation that is easy to compute. The theoretical results are validated using the R* distributed relational database system. Although we use database terminology throughout the paper, the model is more generally applicable whenever random accesses are made using keys.
An object-oriented query algebras
Authors: Gail M. Shaw, Stanley B. Zdonik
Venue: Proceedings of the second international workshop on Database programming languages (1989)

We define a query algebra for object-oriented databases that fully supports abstract data types and object identity while providing associative access to objects, including a join capability that respects the discipline of data abstraction. The structure of the algebra and the abstract access to objects offer opportunities for query optimization. The algebraic operations take an abstract view of objects and access typed collections of objects only through the public interface defined for the type. The algebra supports access to relationships implied by the structure of the objects, ai well as the definition and creation of new relationships between objects. We introduce two notions of object equality to support the creation of new objects by the algebraic operations.
A Maximum Likelihood Framework for Determining Moving Edges
Authors: P. Bouthemy
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

The determination of moving edges in an image sequence is discussed. An approach is proposed that relies on modeling principles and likely hypothesis testing techniques. A spatiotemporal edge in an image sequence is modeled as a surface patch in a 3-D spatiotemporal space. A likelihood ratio test enables its detection as well as simultaneous estimation of its related attributes. It is shown that the computation of this test leads to convolving the image sequence with a set of predetermined masks. The emphasis is on a restricted but widely relevant and useful case of surface patch, namely the planar one. In addition, an implementation of the procedure whose computation cost is merely equivalent to a spatial gradient operator is presented. This method can be of interest for motion-analysis schemes, not only for supplying spatiotemporal segmentation, but also for extracting local motion information. Moreover, it can cope with occlusion contours and important displacement magnitude. Experiments have been carried out with both synthetic and real images.
A Fault-Tolerant Mapping Scheme for a Configurable Multiprocessor System
Authors: Woei Lin, Chuan-Lin Wu
Venue: IEEE Transactions on Computers (1989)

A fault-tolerant mapping scheme for a configurable multiprocessor system using multistage interconnection networks is presented. By adapting its interprocessor connections, the multiprocessor system can provide many regular topological configurations suitable for a variety of parallel computation applications. The configurability of the system is achieved by applying a set of configuration procedures to a linear address space of the system. The central idea behind the scheme is the use of two transformations to restore the linear address space in the presence of processor failures. The fault-tolerant mapping scheme is composed of three algorithms. The algorithms adaptively use the two transformations to handle three different types of faults: single faults, double faults, and triple or greater faults. It is shown that when there are a few processor failures, the algorithms can effectively achieve fault-free linear subspaces with graceful degradation.
V-Pascal: an automatic vectorizing compiler for Pascal with no language extensions
Authors: T. Tsuda, Y. Kunieda
Venue: Proceedings of the 1988 ACM/IEEE conference on Supercomputing (1988)

Detailed anatomy of automatic vectorizing compiler V-Pascal (Version 1, now operational) is given. With no language extensions, V-Pascal efficiently vectorizes the whole of arbitrarily given multiply nested for loops using the mechanism of vector indirect addressing. Higher functions of V-Pascal, such as (a) vectorization of while-do and recursive calls, (b) vectorization of relational operations on relational database defined by record-type data structures, and (c) automatic parallel decomposition for multiprocessor environments, are considered for Version 2 and are now in the process of design and implementation.