ppxscal/embedding_network huggingface dataset:
CLASS simulation of real time, highly compressed video transmission through an interference limited environment
Authors: R. Godfrey, R. Avant, D. Lai, J. Wang
Venue: Proceedings of the 21st conference on Winter simulation (1989)

CLASS (Communication Link Analysis and Simulation System) has been modified to predict the performance of digital video telemetry systems in remotely controlled spacecraft robotics applications where the communications link may be highly corrupted by RFI (radio frequency interference). Unlike previous functional type simulations which use statistical models to characterize the steady-state channel, this new CLASS tool is an emulation type simulator which is capable of modeling both transient and steady-state conditions in the channel. The system architecture uses sequential tasking to simulate bit-by-bit signal processing through each successive component of the channel. Subsystems are: 1) the digital video data compression and reconstruction subsystem; 2) the Reed-Solomon Codec subsystem; and 3) the TDRSS Link subsystem. Subsystems 2 3 form a concatenated coded channel using a Reed-Solomon outer code and a convolutional inner code. The novel features of the software package are: 1) the modular design offers easy modification of the system configuration; 2) it provides extensive performance characterizations of channel components and subsystems including loss of synchronization and reacquisition; 3) through statistical reduction and transformation of emulation type simulation data bases, the simulator may be reconfigured to a speedy, efficient functional type simulation. This paper describes the capabilities, structure and modeling techniques of this new version of the CLASS as it is used in modeling the Orbital Maneuvering Vehicle (OMV) video telemetry return (VDTLMRTN) channel.
A Linear Algebraic Model of Algorithm-Based Fault Tolerance
Authors: J. Anfinson, F. T. Luk
Venue: IEEE Transactions on Computers (1988)

A linear algebraic interpretation is developed for previously proposed algorithm-based fault tolerance schemes. The concepts of distance, code space, and the definitions of detection and correction in the vector space R/sup n/ are explained. The number of errors that can be detected or corrected for a distance-(d+1) code is derived. It is shown why the correction scheme does not work for general weight vectors, and a novel fast-correction algorithm for a weighted distance-5 code is derived.
The use of forward difference equations in animation of physical phenomena
Authors: Sandra J. Cynar
Venue: ACM SIGNUM Newsletter (1988)

In the entertainment industry graphical images are often produced without adherence to physically accurate models. This is usually the case because there is a need to reduce production time and costs. The physical scientist, on the other hand, must produce graphical images that are accurate simulations of the physical phenomena they are attempting to visualize. Frequently the data that an accurate simulation produces can be difficult to use for rendering the animation. This paper describes the use of numerical methods to minimize the number of keyframes for an accurate animation.
Integrated Concurrency-Coherency Controls for Multisystem Data Sharing
Authors: D. M. Dias, B. R. Iyer, John T. Robinson, P. S. Yu
Venue: IEEE Transactions on Software Engineering (1989)

The authors propose an integrated control mechanism and analyze the performance gain due to its use. An extension to the data sharing system structure is examined in which a shared intermediate memory is used for buffering and for early commit processing. Read-write-synchronization and write-serialization problems arise. The authors show how the integrated concurrency protocol can be used to overcome both problems. A queueing model is used to quantify the performance improvement. Although using intermediate memory as a buffering device produces a moderate performance benefit, the analysis shows that more substantial gains can be realized when this technique is combined with the use of an integrated concurrency-coherency control protocol.
Design and implementation of the interface to compiled languages in APL*PLUS II
Authors: James G. Wheeler
Venue: ACM SIGAPL APL Quote Quad (1990)

APL*PLUS II is a second-generation 32-bit APL interpreter that runs under the MS DOS operating system. A recent release has introduced two new system functions &mdash; ONA and OMLOAD &mdash; that enable APL to dynamically load and execute programs written in compiled languages such as C and Fortran. These enhancements presented both design and implementation challenges. On the design side, it was necessary to make it as easy as possible for the APL programmer to integrate non-APL routines into applications. The implementation side required considerable technical creativity and invention, since the MS DOS environment provides no built-in functions for dynamic loading and execution of programs.
Symbolic and algebraic manipulation for formulae of interpolation and quadrature
Authors: Q.-S. Tao
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

Computer Algebra has been used for construction and analysis of algorithms of numerical computation. In this paper, an attempt has been made to derive the formulae of interpolation and quadrature with Computer Algebra. In REDUCE language, the formula manipulation system for interpretation INTEP and for quadrature QUADRAT are developed. The two formula manipulators can be used to derive LaGrange, Hermite and Birkhoff interpolation formulae with any degree of polynomials and to derive Newton-Cotes quadrature formulae and the quadrature formulae involving the derivatives of the integrand.
Systolic s/sup 2/-Way Merge Sort is Optimal
Authors: Hartmut Schmeck, Heiko Schröder, Christoph Starke
Venue: IEEE Transactions on Computers (1989)

The time complexity of Thompson and Kung's (1977) s/sup 2/-way merge sort is analyzed and shown to be asymptotically optimal with respect to the recently improved lower bound on sorting on a mesh-connected n*n array. New lower bounds for systolic sorting are derived. A systolic version of s/sup 2/-way merge sort is systematically constructed and shown to be asymptotically optimal as well.
Priority-driven, preemptive I/O controllers for real-time systems
Authors: B. Sprunt, D. Kirk, L. Sha
Venue: ACM SIGARCH Computer Architecture News (1988)

Current I/O controller architectures inhibit the use of priority-driven preemptive scheduling algorithms that can guarantee hard deadlines in real-time systems. This paper examines the effect of three I/O controller architectures upon schedulable utilization, which is the highest attainable resource utilization at or below which all deadlines can be guaranteed. FIFO request queueing, priority queueing, and priority queueing with preemptable service are simulated for a range of CPU computation to I/O traffic ratios. The results show that, for I/O bound tasks sets and zero preemption costs, priority queueing with preemptable service can provide a level of schedulable utilization 35% higher than that attainable with FIFO queueing and 20% higher than priority queueing and nonpreemptable service. Although the potential gain for priority queueing with preemptable service is large, further simulations that incorporate a time penalty for each preemption show that the gain is very sensitive to preemption cost. With preemption cost represented as a ratio of preemption time to the minimum task period, the level of schedulable utilization for priority queueing with preemptable service degrades to that of priority queueing with nonpreemptable service, for a preemption cost ratio of 0.04. A high level design of a preemptable I/O controller is described and the issues determining preemption cost are detailed along with techniques for its minimization.*
The user's role in a simulation based scheduling system
Authors: F. H. Grant, R. G. Lagoni
Venue: Proceedings of the 21st conference on Winter simulation (1989)

This paper focuses on the role of the production scheduler in developing and using a computer simulation based scheduling system. As the scheduling system end user, the production scheduler is responsible for developing schedules which support the business goals of the manufacturing facility. To do so, he must balance many conflicting objectives relating to work-in-process inventory levels, resource utilizations, and customer service. During any single scheduling period, the desired balance may vary with time or across production resources. Simulation based scheduling does not provide an optimum solution, but provides visibility into the effects of decisions. The production scheduler uses this information to perform analyses and to identify opportunities to improve the plan. His participation during system development ensures that the model and reports fully support these activities. While the schedule generation and revision process can be automated, the final analysis of the value of the resulting schedule requires human involvement. A FACTOR scheduling software application is reviewed to illustrate the role of the user in this dynamic environment.
Integrating noninterfering versions of programs
Authors: Susan Horwitz, Jan Prins, Thomas Reps
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1989)

The need to integrate several versions of a program into a common one arises frequently, but it is a tedious and time consuming task to integrate programs by hand. To date, the only available tools for assisting with program integration are variants of text-based differential file comparators; these are of limited utility because one has no guarantees about how the program that is the product of an integration behaves compared to the programs that were integrated. This paper concerns the design of a semantics-based tool for automatically integrating program versions. The main contribution of the paper is an algorithm that takes as input three programs A, B, and Base, where A and B are two variants of Base. Whenever the changes made to Base to create A and B do not &ldquo;interfere&rdquo; (in a sense defined in the paper), the algorithm produces a program M that integrates A and B. The algorithm is predicated on the assumption that differences in the behavior of the variant programs from that of Base, rather than differences in the text, are significant and must be preserved in M. Although it is undecidable whether a program modification actually leads to such a difference, it is possible to determine a safe approximation by comparing each of the variants with Base. To determine this information, the integration algorithm employs a program representation that is similar (although not identical) to the dependence graphs that have been used previously in vectorizing and parallelizing compilers. The algorithm also makes use of the notion of a program slice to find just those statements of a program that determine the values of potentially affected variables. The program-integration problem has not been formalized previously. It should be noted, however, that the integration problem examined here is a greatly simplified one; in particular, we assume that expressions contain only scalar variables and constants, and that the only statements used in programs are assignment statements, conditional statements, and while-loops.
Object oriented languages and actors: which language for a distributed approach?
Authors: F. Carre, P. Clere
Venue: ACM SIGPLAN Notices (1989)

In the last years, hardware research has produced new parallel architectures. Now, it is time to define a language adapted to run applications in Artificial Intelligence area on these architectures.
Reflective facilities in Smalltalk-80
Authors: B. Foote, R. E. Johnson
Venue: ACM SIGPLAN Notices (1989)

Computational reflection makes it easy to solve problems that are otherwise difficult to address in Smalltalk-80, such as the construction of monitors, distributed objects, and futures, and can allow experimentation with new inheritance, delegation, and protection schemes. Full reflection is expensive to implement. However, the ability to override method lookup can bring much of the power of reflection to languages like Smalltalk-80 at no cost in efficiency.
A sequencing-based taxonomy of I/0 systems and review of historical machines
Authors: M. Smotherman
Venue: ACM SIGARCH Computer Architecture News (1989)

A new taxonomy for I/O systems is proposed that is based on the program sequencing necessary for the control of I/O devices. A review of historical machines demonstrates the need for a more comprehensive categorization than previously published and reveals the historical firsts of I/O interrupts in the NBS DYSEAC, DMA in the IBM SAGE (AN/FSQ-7), the interrupt vector concept in the Lincoln Labs TX-2, and fully symmetric I/O in the Burroughs D-825 multiprocessor.
Cache considerations for multiprocessor programmers
Authors: Mark D. Hill, James R. Larus
Venue: Communications of the ACM (1990)

Although caches in most computers are invisible to programmers, they significantly affect program performance. This is particularly true for cache-coherent, shared-memory multiprocessors. This article presents recent research into the performance of parallel programs and its implications for programmers who may know little about caches.
Simultaneous Parameter Estimation and Segmentation of Gibbs Random Fields Using Simulated Annealing
Authors: S. Lakshmanan, H. Derin
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

An adaptive segmentation algorithm is developed which simultaneously estimates the parameters of the underlying Gibbs random field (GRF)and segments the noisy image corrupted by additive independent Gaussian noise. The algorithm, which aims at obtaining the maximum a posteriori (MAP) segmentation is a simulated annealing algorithm that is interrupted at regular intervals for estimating the GRF parameters. Maximum-likelihood (ML) estimates of the parameters based on the current segmentation are used to obtain the next segmentation. It is proven that the parameter estimates and the segmentations converge in distribution to the ML estimate of the parameters and the MAP segmentation with those parameter estimates, respectively. Due to computational difficulties, however, only an approximate version of the algorithm is implemented. The approximate algorithm is applied on several two- and four-region images with different noise levels and with first-order and second-order neighborhoods.
Correlation-induction techniques for fitting second-order metamodels in simulation experiments
Authors: J. D. Tew
Venue: Proceedings of the 21st conference on Winter simulation (1989)

This paper identifies two correlation-based strategies for designing a simulation experiment to estimate a second-order metamodel of the relationship between the levels of the input factors and the response of interest. Both strategies are shown to be superior to the method of independent random number streams. In the past, correlation-based strategies for metamodel estimation in simulation experiments has focused on first-order metamodels. However, in many simulation experiments it is reasonable to expect that the relationship between the levels of the input factors and the response of interest is better approximated by a second-order metamodel. Thus second-order metamodels are, typically, of more interest to the simulation analyst. Both proposed strategies use the variance reduction technique of common random numbers to induce positive correlations between responses across design points and antithetic variates across replicates. For a large class of experimental designs and with respect to a variety of optimality criteria, both strategies are shown to give better estimates of the vector of unknown coefficients in the metamodel than the method of independent random number streams across all design points. A numerical example is given to illustrate this point and to show that in practice, the second strategy yields better metamodel estimates than the first strategy.
Logic programming as constructivism: a formalization and its application to databases
Authors: F. Bry
Venue: Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1989)

The features of logic programming that seem unconventional from the viewpoint of classical logic can be explained in terms of constructivistic logic. We motivate and propose a constructivistic proof theory of non-Horn logic programming. Then, we apply this formalization for establishing results of practical interest. First, we show that 'stratification' can be motivated in a simple and intuitive way. Relying on similar motivations, we introduce the larger classes of 'loosely stratified' and 'constructively consistent' programs. Second, we give a formal basis for introducing quantifiers into queries and logic programs by defining 'constructively domain independent' formulas. Third, we extend the Generalized Magic Sets procedure to loosely stratified and constructively consistent programs, by relying on a 'conditional fixpoint' procedure.
Task-oriented parsing - a diagnostic method to be used adaptive systems
Authors: H. U. Hoppe
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1988)

In order to be able to show context-dependent responses to the user's actual needs, adaptive systems have to be provided with models of possible task contexts. Existing methods for the representation of tasks in HCI are insufficient for this purpose as they do not support task-oriented parsing (i.e. analysing the input stream in terms of higher level task units). This paper presents a Prolog implementation of a task-oriented parser (+ generator) based on a grammar notation called LEXITAS. As an application, an online coach for a UNIX-like file management system is described. Further applications, such as automated macro detection from given interaction protocols, are discussed.
All example of using pseudofields to eliminate version shuffling in horizontal code compaction
Authors: J. L. Linn, C. D. Ardoin
Venue: Proceedings of the 22nd annual workshop on Microprogramming and microarchitecture (1989)

This paper first reviews the version shuffling problem for microcode compaction. Next, a somewhat representative compaction problem involving asymmetric ALUs and a port-limited register file is presented. Finally, the paper shows how to model the architecture in a microcode compiler using the concept of pseudofields. While the modeling process is nontrivial, it is seen that this approach solves the version shuffling problem without introducing early-binding inefficiencies in the compiled code.
An Eigendecomposition Approach to Weighted Graph Matching Problems
Authors: S. Umeyama
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

An approximate solution to the weighted-graph-matching problem is discussed for both undirected and directed graphs. The weighted-graph-matching problem is that of finding the optimum matching between two weighted graphs, which are graphs with weights at each arc. The proposed method uses an analytic instead of a combinatorial or iterative approach to the optimum matching problem. Using the eigendecompositions of the adjacency matrices (in the case of the undirected-graph-matching problem) or Hermitian matrices derived from the adjacency matrices (in the case of the directed-graph-matching problem), a matching close to the optimum can be found efficiently when the graphs are sufficiently close to each other. Simulation results are given to evaluate the performance of the proposed method.
IRX: an information retrieval system for experimentation and user applications
Authors: D. Harman, D. Benson, L. Fitzpatrick, R. Huntzinger, C. Goldstein
Venue: ACM SIGIR Forum (1988)

IRX is a text retrieval system designed to be a testbed for conducting information retrieval research on statistically-based retrieval strategies in either batch or interactive modes. The modular structure of IRX has permitted major changes in components of the system (e.g., ranking algorithms, parsers, interfaces; without redesign. As an interactive system IRX is in use at the Johns Hopkins University and the Lister Hill Center providing access to databases in human and molecular genetics.
Why simulation works
Authors: A. Alan B. Pritsker
Venue: Proceedings of the 21st conference on Winter simulation (1989)

Simulation works because it deals with reality. We simulate models of real systems. We get closer to the system than any other type of modeler. We study the old system, collect data, understand first principles about the system, check out procedures in use before we start modeling, and we test proposed solutions against current operations or baseline designs. We do not force a system into a preconceived normative model. We strive to have our models used and our best alternatives implemented. We stay with a problem until a solution is implemented. We recognize that the model upon which we make our recommendations contains additional information and insights that are useful during implementation.
The standard factor
Authors: P. Billingsley
Venue: ACM SIGCHI Bulletin (1989)

This quarter's column focuses on standard user interfaces, as opposed to user interface standards. User interface standards attempt to ensure that certain minimum software usability criteria are met, regardless of the specific type or style of user interface implemented. A standard user interface, on the other hand, is based on a set of design rules, guidelines, or conventions that describe the specific appearance and behavior of interface elements. In theory, if developers adhere to these specifications, the user interfaces they design will be consistent with all others designed under the same constraints. The following article, reprinted with permission of the author and IEEE, discusses many of the difficulties associated with standard user interfaces from a human factors perspective. It is precisely because of these difficulties that, even if the entire industry agreed to adopt one standard user interface, there would still be a need for higher-level user interface standards.
DVI&mdash;a digital multimedia technology
Authors: G. David Ripley
Venue: Communications of the ACM (1989)

A digital presentation technology that manages anything from text to full-motion video has the potential of expanding the usefulness of personal computers, while rendering them less intimidating.
A Generalized Expert System for Database Design
Authors: A. Dogac, Birol Yürüten, Stefano Spaccapietra
Venue: IEEE Transactions on Software Engineering (1989)

Generalized Expert System for Database Design (GESDD) is a compound expert system made up of two parts: (1) an expert system for generating methodologies for database design, called ESGM; and (2) an expert system for database design, called ESDD. ESGM provides a tool for the database design expert to specify different design methodologies or to modify existing ones. The database designer uses ESDD in conjunction with one of these methodologies to design a database starting from the requirement specification phase and producing a logical schema in one of the well-known data models, namely, the hierarchical data model, the network data model, or the relational data model. The system is evolutive in the sense that an existing methodology can be modified or a novel methodology can be added to the existing ones. GESDD is a menu-driven system and it is coded in Prolog.