ppxscal/embedding_network huggingface dataset:
Performance analysis of Time Warp with homogeneous processors and exponential task times
Authors: Anurag Gupta, Ian Akyildiz, Richard M. Fujimoto
Venue: ACM SIGMETRICS Performance Evaluation Review (1991)

The behavior of n interacting processors synchronized by the "Time Warp" protocol is analyzed using a discrete state continuous time Markov chain model. The performance and dynamics of the processes are analyzed under the following assumptions: exponential task times and times-tamp increments on messages, each event message generates one new message that is sent to a randomly selected process, negligible rollback, state saving, and communication delay, unbounded message buffers, and homogeneous processors that are never idle. We determine the fraction of processed events that commit, speedup, rollback probability, expected length of rollback, the probability mass function for the number of uncommitted processed events, and the probability distribution function for the virtual time of a process. The analysis is approximate, so the results have been validated through performance measurements of a Time Warp testbed (PHOLD workload model) executing on a shared memory multiprocessor.
Multi-dimensional modelling and measurement of software designs
Authors: Martin Shepperd, Darrel Ince
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

Design structure measures are example of a class of metrics that may be derived early on in a software project; they are useful indicators of design weaknesses - weaknesses which, if uncorrected, lead to problems of implementation, reliability and maintainability. Unfortunately, structure metrics are limited in their ability to model system architecture since they are insensitive to component size. Thus, architectures that trade structural complexity for very large components may not be detected. This paper has two concerns. First, we consider the problem of adequately measuring component size at design time. Various existing metrics are evaluated and found to be deficient. Consequently, a new, more flexible approach based upon the traceability from system requirements to design components, is proposed. Second, we address the issue of multi-dimensional modelling (in this case structure and size). We apply outlier analysis techniques to identify three classes of problem design component and relate our work to an empirical study of 62 modules. The results suggest that augmenting the more traditional approach of a single structure metric with an additional perspective, that of module size, considerably enhances the ability of design metrics to isolate problem components. It is our belief that far more sophisticated software modelling techniques, such as the multi-dimensional approach we present, are required, if measurement and modelling is to reach its full potential, as an integral part of software engineering processes.
Algorithms for Musical Composition: A Question of Granularity
Authors: Stephen W. Smoliar
Venue: Computer (1991)

Early approaches to computer-generated music are examined, and it is argued that making music is concerned with a higher level of granularity than that of the notes on music paper. Work in artificial intelligence shows that low-level decisions such as the selection of individual notes may actually be subordinate to a model-based control structure, the models being examples of how problems have been resolved. It is suggested that the search for algorithmic rules should be directed by two questions: how to identify units of material of the appropriate granularity, and, given a collection of those units, how to properly assemble them.
Implementation of an iteration macro
Authors: Bill van Melle
Venue: ACM SIGPLAN Lisp Pointers (1990)

This article describes the implementation of a set of iteration macros. These macros are found in the Portable Common Loops (PCL) implementation of the Common Lisp Object System, though they are not dependent on PCL in any way. The macros were designed to be more functional than the small set of iteration macros found in Common Lisp (e.g., do), while still having a "Lisp-like" syntax that is easy to understand and extend. Pavel Curtis is responsible for the essential insights about program transformation that make feasible an efficient implementation of this conceptually simple iteration form. The implementation makes extensive use of the PCL code walker, which was described in the previous issue of Lisp Pointers.
Asymptotic Expansions for Large Closed Queueing Networks with Multiple Job Classes
Authors: Charles Knessl, Charles Tier
Venue: IEEE Transactions on Computers (1992)

A closed BCMP queuing network consisting of R job classes (chains), K+1 single-server, fixed-rate nodes, and M/sub j/ class j jobs (j=1, 2, . . ., R) is considered. Asymptotic expansions are constructed for the partition function under assumptions (1) K
Adaptive Programming
Authors: Mohamed G. Gouda, Ted Herman
Venue: IEEE Transactions on Software Engineering (1991)

An adaptive program is one that changes its behavior base on the current state of its environment. This notion of adaptivity is formalized, and a logic for reasoning about adaptive programs is presented. The logic includes several composition operators that can be used to define an adaptive program in terms of given constituent programs; programs resulting from these compositions retain the adaptive properties of their constituent programs. The authors begin by discussing adaptive sequential programs, then extend the discussion to adaptive distributed programs. The relationship between adaptivity and self-stabilization is discussed. A case study for constructing an adaptive distributed program where a token is circulated in a ring of processes is presented.
Implementing Telos
Authors: Bryan M. Kramer, Vinay K. Chaudhri, Manolis Koubarakis, Thodoros Topaloglou, Huaiqing Wang, John Mylopoulos
Venue: ACM SIGART Bulletin (1991)

This paper describes experiences in implementing Telos [MBJK90, TK89], a knowledge representation scheme developed at the University of Toronto. In a nutshell, Telos is a hybrid of an object-centered representation for representing entities, a logic-based language for representing deductive rules and integrity constraints, and an interval-based language for representing time. The language is unique for its tight integration of temporal knowledge and for its meta-level capabilities which include a class/metaclass hierarchy and a reflective inference engine.
Multilevel synthesis minimizing the routing factor
Authors: P. Abouzeid, K. Sakouti, G. Saucier, F. Poirot
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

This paper presents a multilevel synthesis method on standard cells aiming at reducing both gate and wiring areas. The goal is to decrease the routing factor which is defined as the ratio between the routing area and the gate area. The wiring is taken into account during the synthesis steps (factorization and technology mapping). The approach is based on lexicographical expression of Boolean function controlling input dependency, and on kernel filtering controlling excessive factorizations responsible for wiring complexity increase.
The principles of visual rhetoric and the rhetoric of visual principles
Authors: T. R. Girill
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1992)

The basic insight of "Seeing the Text" is that as technical texts range through the continuum from the visually uninformative to those full of visible cues to their content, they change not just superficially but rather in linguistic and organizational ways that are very important rhetorically. Bernhardt advances this argument with a case study of a visually structured brochure, during which he appeals to four "laws of gestalt" to explain why the phrases, sentences, and subdivisions of the text have special "localized" features that improve their usefulness. Unfortunately, the graphics principles to which Bernhardt appeals are too vague (or sometimes insufficiently relevant) to do the explanatory job he assigns to them. A review of related work by Edward Tufte, Jill Larkin, and Herbert Simon, however, yields other principles of visual rhetoric (involving data-ink ratios and perceptual inferences) that are more relevant and specific, and that in fact entail just the localization features Bernhardt predicted. Thus, his claims about the pedagogic importance of appreciating visually informative text have been amply vindicated by parallel, independent studies on envisioning information effectively.
Constrained Restoration and the Recovery of Discontinuities
Authors: Donald Geman, George Reynolds
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

The linear image restoration problem is to recover an original brightness distribution X/sup 0/ given the blurred and noisy observations Y=KX/sup 0/+B, where K and B represent the point spread function and measurement error, respectively. This problem is typical of ill-conditioned inverse problems that frequently arise in low-level computer vision. A conventional method to stabilize the problem is to introduce a priori constraints on X/sup 0/ and design a cost functional H(X) over images X, which is a weighted average of the prior constraints (regularization term) and posterior constraints (data term); the reconstruction is then the image X, which minimizes H. A prominent weakness in this approach, especially with quadratic-type stabilizers, is the difficulty in recovering discontinuities. The authors therefore examine prior smoothness constraints of a different form, which permit the recovery of discontinuities without introducing auxiliary variables for marking the location of jumps and suspending the constraints in their vicinity. In this sense, discontinuities are addressed implicitly rather than explicitly.
Implementation of classical mutual exclusion algorithms in Ada
Authors: Faisel Saeed, K. M. George, M. H. Samadzadeh
Venue: ACM SIGAda Ada Letters (1992)

This paper presents a scheme for defining a simulation environment for n-process mutual exclusion algorithms based on an Ada virtual machine. Several algorithms have been implemented and tested in this simulation environment.
Searching on a Tape
Authors: S. W. Hornick, S. R. Maddila, E. P. Mücke, H. Rosenberger, S. S. Skiena, I. G. Tollis
Venue: IEEE Transactions on Computers (1990)

The problem of minimizing the average time to search for a key in a stored list of keys in a sequential access machine model (SAM) (e.g. a magnetic tape) is considered. The time to access a key in the list and the time to compare it to the given search key are taken into account. The time to access a key in the list is assumed proportional to the distance the head moves from its current location to reach the key. The time to read and compare the key to the search key is taken to be constant. Two classes of algorithms are analyzed and a matching lower bound on the average search time is presented. These results answer an open problem posed by S. Nishihara and H. Nishino (1987) regarding the optimal search algorithm for such a model. It is shown that the organization of the input data is crucial in determining the SAM complexity of the search problem.
A comparison of object oriented simulation languages (abstract)
Authors: Robert A. Campbell, Suzanne Jones, Rachelle Cottle
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

A network computer system was simulated as a single server queuing system using several computer languages including two object oriented languages. An initial simulation using Smalltalk-V was implemented on a Mackintosh II microcomputer. A procedure oriented Pascal program was then implemented on the Mack II machine. A HP Vectra PC was then used to implement the same problem in Pascal, with and without an object oriented option on Turbo Pascal 5.5. The programming was performed by two undergraduate computer science students with considerable programming experience, but who were using object oriented concepts for the first time. Developing the model of the network system to be simulated and implementing it in an object oriented language took several weeks. However, once the task was complete, implementing the model in the three other methods described was fairly simple. Both students found that using an object oriented system in a programming environment supplied by Smalltalk V was a little different than programming in a procedure oriented language such as Pascal. Once they became familiar with the Smalltalk environment, they both felt that they would prefer to develop simulation systems in Smalltalk. The code lengths of the programs were each about 500 lines, with Smalltalk V being somewhat less and Turbo Pascal 5.5 somewhat more. Run times were significantly different, however. Smalltalk-V run time for 10 replications of the simulation was 2.7 minutes, with structured Pascal taking 5.5 minutes, each on the Mack II microcomputer. Structured Pascal took 1.5 minutes on the HP Vectra, but Turbo 5.5 took 36 minutes. If this same ratio of times applies (i.e., the HP Vectra being 5.5/1.5 time as fast as the Mack II), then we would expect object oriented Turbo 5.5 to take 132 minutes to run on the Mack II. At least we found that the object oriented approach can be either faster or slower than a structured approach.
The relationship of application risks to application controls: a study of microcomputer-based database applications
Authors: Robert A. Schultheis, Mary Summer
Venue: ACM SIGCPR Computer Personnel (1991)

End-user computing has posed serious concerns to MIS professionals for a number of years. One of the primary concerns harbored by MIS professionals is the quality of the end-user applications that are developed by those whose primary function and training are outside the information systems field. MIS professionals are naturally apprehensive about the applications developed by relatively naive users. These professionals fear that the applications developed will not possess sufficient controls and that these poorly controlled applications will create significant risks to the users and to the organizations for which they work.
Two recent developments in tree adjoining grammars: semantics and efficient processing
Authors: Yves Schabes, Aravind K. Joshi
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

During the past year there have been two very significant developments in the area of Tree Adjoining Grammars (TAGs).The first development is a variant of TAGs, called synchronous TAGs, which allows TAG to be used beyond the confines of syntax by characterizing correspondences between languages. The formalism's intended usage is to relate expressions of natural languages to their associated semantics represented by a logical form language in TAG, or to their translates in another natural language. The formalism is incremental and inherently nondirectional. We will show by detailed examples the working of synchronous TAGs and some of its applications, for example in generation and in machine translation.The second development is the design of LR-style parsers for TAGs. LR parsing strategies evolved out of the original work of Knuth. Even though they are not powerful enough for NLP, they have found use in natural language processing (NLP) by solving by pseudo-parallelism conflicts between multiple choices. This gives rise to a class of powerful yet efficient parsers for natural language. In order to extend the LR techniques to TAGs it is necessary to find bottom-up automaton that is exactly equivalent to TAGs. This is precisely what has been achieved by the discovery of the Bottom-up Embedded Push Down Automaton (BEPDA). Using BEPDA, deterministic left to right parsers for the Tree Adjoining Languages have been developed.
Joint use of simulation and nonlinear curve fitting in compartmental models (abstract)
Authors: Meyer Katzper
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

Simulation and nonlinear fitting programs allow a greater role for human experience and judgement when used jointly in obtaining the best ranges and fit for the parameters of compartmental models. Currently available software provides graphical interfaces which make a viewing and intervention strategy attractive and efficient. This is especially the case in nonlinear models where required initial estimates can lead to false solution due to local minima. Simulations can be used which provide graphical displays for comparison with experimental data to obtain parameter ranges and initial estimates. This approach was applied to compartmental models which are used in pharmacokinetics. The models provide a useful simplified phenomenological representation of drug disposition and concentration. The resulting nonlinear equations are parameterized by clearance, volume and rate constants. The parametric values are used in making dosing and therapy decisions. The problem of determining the pharmacokinetic parameters from observations is called the identification problem. Nonlinear fitting approaches, with iterative search algorithms, are sensitive to the initial estimates assumed for the parameters. Difference equation simulations can easily represent a wide variety of compartmental models. Their results can be used to provide initial estimates for the nonlinear curve fitting programs. Possibly more importantly, comparing the model output with the experimental data will aid in deciding whether an appropriate compartmental model was specified. Current work has focused on using NONMEM (Nonlinear Mixed Effects Modeling) for population pharmacokinetics and Stella for simulation.
Interactive communication: balanced distributions, correlated files, and average-case complexity
Authors: Alon Orlitsky
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

Suppose (X,Y) is a pair of random variables distributed over a support set S. Person P/sub x/ knows X, person P/sub y/ knows Y, and both know S. Using a predetermined protocol, they exchange binary messages in order for P/sub y/ to learn X. P/sub x/ may or may not learn Y. Bounds on communication complexity are obtained and used to obtain efficient protocols for the correlated files problem where X and Y are binary strings (files) within a small edit distance from each other. The average number of bits required for P/sub y/ to learn X when at most m messages are permitted is also determined.
Distributed and parallel demand driven logic simulation
Authors: K. Subramanian, M. R. Zargham
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

Based on the demand-driven approach, distributed and parallel simulation algorithms are proposed. Demand-driven simulation tries to minimize the number of component computations by performing only those required for the watched output requests. For a specific output value request, the input line values that are required are requested from the related component. The process continues until known system input signal values are requested. We present a distributed demand-driven algorithm with an infinite memory requirement (but still the memory required by each process is not greater than that of sequential demand-driven simulation), and a parallel demand-driven simulation with reduced memory requirement. In our algorithms, each component is assigned a logical process.
On statecharts with overlapping
Authors: David Harel, Chaim-arie Kahana
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1992)

The problem of extending the language of statecharts to include overlapping states is considered. The need for such an extension is motivated and the subtlety of the problem is illustrated by exhibiting the shortcomings of naive approaches. The syntax and formal semantics of our extension are then presented, showing in the process that the definitions for conventional statecharts constitute a special case. Our definitions are rather complex, a fact that we feel points to the inherent difficulty of such an extension. We thus prefer to leave open the question of whether or not it should be adopted in practice.
Lilac: A Two-View Document Editor
Authors: Kenneth P. Brooks
Venue: Computer (1991)

A description is given of Lilac, an experimental document preparation system designed to provide the best of both the WYSIWYG (what you see is what you get) and the document compiler approaches. It does this by offering both WYSIWYG editing and language-based document description as two views side by side on the screen. The page view is a WYSIWYG editor showing a close approximation to the printed output. The source view shows a programlike description of the document in a special-purpose language. This language supports subroutines, variables, and conditional execution, and is designed to encourage the use of subroutines to embody structure. Both views are editable, but Lilac is designed with the expectation that most editing will occur in the page view.
Calling APL2 from COBOL
Authors: Don Erickson
Venue: ACM SIGAPL APL Quote Quad (1991)

This paper will discuss the reasons why a need came up for COBOL to call APL2 functions as executable modules, the methods used to complete the interface, and the benefits and concerns that arose during implementation and maintenance.
Report on the programming language Haskell: a non-strict, purely functional language version 1.2
Authors: Paul Hudak, Simon Peyton Jones, Philip Wadler, Brian Boutel, Jon Fairbairn, Joseph Fasel, María M. Guzmán, Kevin Hammond, John Hughes, Thomas Johnsson, Dick Kieburtz, Rishiyur Nikhil, Will Partain, John Peterson
Venue: ACM SIGPLAN Notices (1992)

"Some half dozen persons have written technically on combinatory logic, and most of these, including ourselves, have published something erroneous. Since some of our fellow sinners are among the most careful and competent logicians on the contemporary scene, we regard this as evidence that the subject is refractory. Thus fullness of exposition is necessory for accurary; and excessive condensation would be false economy here, even more than it is ordinarily."
Software metrics for object-oriented systems
Authors: J. Chris Coppick, Thomas J. Cheatham
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

The application of software complexity metrics within the object-oriented paradigm is examined. Several factors affecting the complexity of an object are identified and discussed. Halstead's Software Science metrics and McCabe's Cyclomatic Complexity metric are extended to an object. A limit for the cyclomatic complexity of an object is suggested.
Fine-grain parallelism in the ALPS programming language
Authors: Prasad Vishnubhotla
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

The ALPS programming language is based on a shared variable model of concurrency where the shared variables have built-in data synchronization. Two classes of shared variables that support fine-grain parallelism are provided, namely, cells and sets. A cell is a single-assignment variable which can be assigned only once but can be read several times by parallel processes. A set is a distributed data structure that can be operated by parallel processes by inserting and removing items. This paper describes the language notation for cells and sets and illustrates their use through examples.