ppxscal/embedding_network huggingface dataset:
A translator from small euclid to pascal
Authors: P. E. Pintelas, K. P. Ventouris, M. D. Papassimakopoulou
Venue: ACM SIGPLAN Notices (1989)

This paper describes the design and implementation of a translator from Small Euclid, an extended subset of the system programming language Euclid, to Pascal. The translator is built with the help of the tools LEX and YACC and consists of three different passes each of which performs some transformations to the input program. During the translation of an input program no intermediate code is generated but the translation to Pascal is direct. The translator performs lexical and syntactic checks and a restricted number of semantic checks before producing an equivalent program in Pascal. The differences between Small Euclid and Pascal are identified and translation proposals are discussed while details of the translator's internal structures and its perfonance are given.
An undergraduate parallel processing laboratory
Authors: Chris Nevison
Venue: ACM SIGCSE Bulletin (1988)

We discuss possibilities for setting up an undergraduate laboratory for parallel processing and how such a laboratory, based on transputers, can be used in a course on parallel processing.
A Method for Attribute Selection in Inductive Learning Systems
Authors: Paul W. Baim
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

A computable measure was developed that can be used to discriminate between attributes on the basis of their potential value in the formation of decision rules by the inductive learning process. This relevance measure is the product of extensions to an information-theoretic foundation that address the particular characteristics of a class of inductive learning algorithms. The measure is also conceptually compatible with approaches from pattern recognition. It is described in the context of a generalized model of the expertise development process, and an experiment is presented in which a significant reduction in the number of attributes to be considered was achieved for a complex medical domain.
Some strategies of reuse in an object-oriented programming environment
Authors: B. M. Lange, T. G. Moher
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: Wings for the mind (1989)

In a single-subject study of a software developer working in an object-oriented programming environment, we found evidence of a development style characterized by pervasive software reuse. The subject employed regular strategies for template selection and coding in her work, and avoided techniques requiring deep understanding of code details or symbolic execution whenever possible. Within the limits of the design of the study, the subject's performance is related to attributes of object-oriented programming and our interpretation of the mature mental model with which she approached her task.
Sufficient Condition for a Communication Deadlock and Distributed Deadlock Detection
Authors: B. E. Wojcik, Z. M. Wojcik
Venue: IEEE Transactions on Software Engineering (1989)

The necessary and sufficient condition for deadlock in a distributed system and an algorithm for detection of a distributed deadlock based on the sufficient condition are formulated. The protocol formulated, checks all wait-for contiguous requests in one iteration. A cycle is detected when a query message reaches the initiator. A wait-for cycle is only the necessary condition for the distributed deadlock. A no-deadlock message is expected by the query initiator to infer a deadlock-free situation if at least one wait-for cycle is present. A no-deadlock message is issued by a dependent (query intercessor) that is not waiting-for. No no-deadlock message implies a deadlock, and processes listed in the received query messages are the processes involved in a distributed deadlock. Properties of the protocol are discussed. The authors show that a replication of a requested higher-priority (or older) process can prevent a distributed deadlock (in a continuous deadlock treatment). A replication is shown to recover (in a periodical deadlock handling) a sequence of processes from an indefinite wait-die scheme.
DEBL: a knowledge-based language for specifying and debugging distributed programs
Authors: Wan-Hong S. Cheng, Virgil E. Wallentine
Venue: Communications of the ACM (1989)

DEBL provides a uniform, rigorous, and programming-language-independent environment for distributed program specification and debugging.
Complexity of computation on real algebraic numbers
Authors: Marie-Françoise Roy, Aviva Szpirglas
Venue: Journal of Symbolic Computation (1990)

This paper is devoted to a precise algorithmical and complexity study of a new polynomial time method for formal computations with polynomial inequalities and real algebraic numbers.
Discrete simulation by APL-GPSS: the best of two worlds
Authors: M. v. Baaren, F. H. D. v. Batenberg, H. P. T. v. d. Star
Venue: ACM SIGAPL APL Quote Quad (1989)

GPSS is a discrete simulation language, suitable for queuing systems.Its main advantage is that it is very easy to learn and easy to use, but its disadvantages are that it is very clumsy and also very restricted in its arithmetic (for example it is integer-valued and has very few mathematical functions).For this reasons we designed a GPSS emulator in APL which combines the simple and intuitive syntax of GPSS with the powerful calculation capabilities of APL.The product of this combination is the simulation package APL-GPSS.
Segmentation through Variable-Order Surface Fitting
Authors: P. J. Besl, R. C. Jain
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

The solution of the segmentation problem requires a mechanism for partitioning the image array into low-level entities based on a model of the underlying image structure. A piecewise-smooth surface model for image data that possesses surface coherence properties is used to develop an algorithm that simultaneously segments a large class of images into regions of arbitrary shape and approximates image data with bivariate functions so that it is possible to compute a complete, noiseless image reconstruction based on the extracted functions and regions. Surface curvature sign labeling provides an initial coarse image segmentation, which is refined by an iterative region-growing method based on variable-order surface fitting. Experimental results show the algorithm's performance on six range images and three intensity images.
A Critical-pair/completion based integration algorithm
Authors: A. C. Norman
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

In 1976 Risch [1] proposed a scheme for finding the integrals of forms built up out of transcendental functions that viewed general functions as rational forms in a suitable differential field and represented the polynomial parts of those forms in a distributed rather than recursive way. By using a data representation where all variables were (more or less) equally important this new method seemed to side-step some of the complications that had appeared in his previous scheme [2] where various side-constraints had to be propagated between the levels present in a tower of separate extensions of differential fields, otherwise seen as levels in recursive datastructures. An initial implementation of the method was prepared in the context of the SCRATCHPAD/1 algebra system and demonstrated at the 1976 SYMSAC meeting at Yorktown Heights, a subsequent version for Reduce [3][5] came after that, and made it possible to try the method on a large range of integrals. These practical studies showed up some problems with the method and its implementation. The presentation given here re-expresses the 1976 Risch method in terms of rewrite rules, and thus exposes the major problem it suffers from as a manifestation of the fact that in certain circumstances the set of rewrites generated is not confluent. This difficulty is then attacked using a critical-pair/completion (CPC) approach. For very many integrands it is then easy to see that the initial set of rewrites used in the early implementations [1] and [3] do not need any extension, and this fact explains the high level of competence of the programs involved despite their shaky theoretical foundations. For a further large collection of problems even a simple CPC scheme converges rapidly; when the techniques presented here are applied to the REDUCE integration test suite in all applicable cases a short computation succeeds in completing the set of rewrites and hence gives a secure basis for testing for integrability. This paper describes the implementation of the CPC process and discusses current limitations to and possible future extended applications of it.
Dynamic file migration in distributed computer systems
Authors: Bezalel Gavish, Olivia R. Liu Sheng
Venue: Communications of the ACM (1990)

The importance of file migration is increasing because of its potential to improve the performance of distributed office, manufacturing and hospital information systems. To encourage research in the file migration problem, the authors summarize accomplishments of researchers of the problem, provide a detailed comparison of file migration and dynamic file allocation problems, and identify important areas of research to support the development of effective file migration policies.
A new model for user services: distributed support
Authors: Michael R. Pear
Venue: Proceedings of the 16th annual ACM SIGUCCS Conference on User Services (1988)

During the 1980's, computing has become broadly available on our campuses beyond the traditional technical disciplines. Improvements in networking and data communications have made mainframe computing more accessible to users in the humanities and social sciences. And personal computers have made computing affordable to individuals and resource-poor departments. With the proliferation of computers and access, the user community which we serve has increased manyfold. Gone are the days when user services staff worked with expert users who understood programming and were willing to put up with the idiosyncrasies of a computing environment. Today, most of the computing on campuses relies on commercially available applications &mdash; not custom-built programs. While computing systems, particularly on personal computers, have become easier to use, there are still system complexities, advanced application features and new ways of thinking to make use of computing tools which go beyond the experience level (and desire to learn) of most users. Lacking depth of understanding, many computers users only slowly assimilate new methods and discover new applications. How can we deal with this larger and more diverse community effectively? I believe the answer is to establish departmentally-based user services staff balanced by a central staff of experts in areas of general interest on campus. Local staff, with a background and interest in the discipline, bring an understanding of computer technology and the applications to the discipline. In many ways, such a structure is evolving naturally as some people who began using computers as tools in their field became interested in the technology itself. These people are known to others in their departments as the local &ldquo;expert&rdquo;, and are consulted informally by others to resolve computing problems. For lack of a common title, we call these people Departmental Computing Coordinators. In this paper, I first discuss an ideal model for distributed support in campus departments. I then discuss how we at Brown are working towards such a model through our Departmental Computing Coordinator Program. I will focus on support for faculty, staff, and graduate students, i.e., those people who are generally associated with a particular unit of a university, and not on student computing.
Objects as closures: abstract semantics of object-oriented languages
Authors: Uday Reddy
Venue: Proceedings of the 1988 ACM conference on LISP and functional programming (1988)

We discuss denotational semantics of object-oriented languages, using the concept of closure widely used in (semi) functional programming to encapsulate side effects. It is shown that this denotational framework is adequate to explain classes, instantiation, and inheritance in the style of Simula as well as SMALLTALK-80. This framework is then compared with that of Kamin, in his recent denotational definition of SMALLTALK-80, and the implications of the differences between the two approaches are discussed.
An Adaptive Hierarchical Routing Protocol
Authors: W. T. Tsai, C. V. Ramamoorthy, W. K. Tsai, O. Nishiguchi
Venue: IEEE Transactions on Computers (1989)

An adaptive hierarchical routing protocol based on the extension of the new Arpanet scheme is proposed and its simulated performance is presented. The protocol can adapt to rapidly changing environments and works for arbitrarily large networks. A number of existing schemes as well as the proposed scheme are simulated under many different environments and clustering structures. The proposed protocol is found to be superior to the other protocols tested in many different types of network traffic and topological configurations. The results indicate that intercluster links must be reliable, because (1) the failure of these links can significantly degrade the routing performance, even though the protocol does not degrade as badly as the existing scheme and (2) hierarchical routing protocols usually prefer small clusters, which means that there will be many intercluster links. The tradeoff between two conflicting performance criteria, response speed and communication overhead, is shown.
Fault-Tolerant Routing in Multistage Interconnection Networks
Authors: A. Varma, C. S. Raghavendra
Venue: IEEE Transactions on Computers (1989)

The fault tolerance of multiprocessor systems with multistage interconnection networks under multiple faults in the network is studied. The fault tolerance is analyzed with respect to the criterion of dynamic full access (DFA) property of the processors in the system. A characterization of multiple faults in the Omega network is introduced and used to develop simple tests for the DFA capability under a given set of faults. It is shown that the DFA capability is maintained under a large number of faults. A maximum of three passes is shown to be sufficient for communication between any two processors in the system when the faults satisfy certain conditions which can be checked easily. For cases in which these conditions do not hold, at most log/sub 2/N-2 passes through the network are shown to be sufficient if a set of weaker conditions is satisfied. Techniques for routing data between processing elements through the faulty network are described. Extension of the results to general k-stage shuffle/exchange networks with k>log/sub 2/N is also given. These techniques allow continued operation of a multiprocessor system in the presence of network faults with full connectivity among the processing elements of the system and minimal loss of network throughput.
Quick simulation of rare events in networks
Authors: R. D. Fresnedo
Venue: Proceedings of the 21st conference on Winter simulation (1989)

We study the problem of how to simulate the occurrence of rare events on networks of queues; an interesting application is to obtain the expected time until the network buffers fill up.We show that the unique optimal (minimum variance) change of measure (importance sampling) to simulate an event is given by the law of the process conditioned on the event (rare or not).Some theory is needed to circumvent the fact that knowledge of the conditional laws implies knowledge of the solution. We present two ways to handle the problem. Boundary theory of Markov Chains provides the theoretical framework. The method sheds light on the way that rare events happen; this in turn explains why some large deviations ("LD" in what follows) heuristics (Walrand and Parekh) fail for important combinations of parameter values (optimal buffer allocation).A compactness argument and a scale-down version of the model are used to simulate successfully the chances of excessive backlogs for many M/M/1 queues in tandem and for any combination of parameters.Alternatively, we can build on the LD heuristics and, using the notion of convex combination of harmonics, we successfully treat the optimal buffer allocation case.
A temporal fixpoint calculus
Authors: M. Y. Vardi
Venue: Proceedings of the 15th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1988)

Two distinct extensions of temporal logic has been recently advocated in the literature. The first extension is the addition of fixpoint operators that enable the logic to make assertions about arbitrary regular events. The second extension is the addition of past temporal connectives that enables the logic to refer directly to the history of the computation. Both extensions are motivated by the desire to adapt temporal logic to modular, i.e., compositional, verification (as opposed to global verification). We introduce and study here the logic &mgr;TL, which is the extension of temporal logic by fixpoint operators and past temporal connectives. We extend the automata-theoretic paradigm to &mgr;TL. That is, we show how, given an &mgr;TL formula @@@@, we can produce a finite-state B&uuml;chi automaton A@@@@, whose size is at most exponentially bigger than the size of @@@@, such that A@@@@ accepts precisely the computations that satisfy @@@@. The result has immediate applications, e.g., an optimal decision procedure and a model-checking algorithm for &mgr;TL.
Mul-T: a high-performance parallel Lisp
Authors: D. A. Kranz, R. H. Halstead,  Jr., E. Mohr
Venue: ACM SIGPLAN Notices (1989)

Mul-T is a parallel Lisp system, based on Multilisp's future construct, that has been developed to run on an Encore Multimax multiprocessor. Mul-T is an extended version of the Yale T system and uses the T system's ORBIT compiler to achieve &ldquo;production quality&rdquo; performance on stock hardware &mdash; about 100 times faster than Multilisp. Mul-T shows that futures can be implemented cheaply enough to be useful in a production-quality system. Mul-T is fully operational, including a user interface that supports managing groups of parallel tasks.
Molecule: A Language Construct for Layered Development of Parallel Programs
Authors: Zhiwei Xu, Kai Hwang
Venue: IEEE Transactions on Software Engineering (1989)

A new language construct, called molecule, is described for the efficient implementation of algorithms on parallel computers. A molecule can be considered a procedure associated with a molecule type. Each molecule type characterizes a particular computation mode (sequential, pipelining, array processing, dataflow, multiprocessing, etc.). Basic concepts of molecule are introduced with a procedural language, called PAL. A concrete example is presented to illustrate layered software development using PAL on a multicomputer (the iPSC). It is concluded that high-level languages, augmented with the molecule construct, offer application flexibility, user friendliness, and efficiency in implementing parallel programs.
The SEA CAB 500 Computer
Authors: Dimitri Starynkevitch
Venue: IEEE Annals of the History of Computing (1990)

The CAB 500 was planned by SEA as a low cost, simple to use computer, primarily for scientific calculations. The technology used was magnetic amplifiers, transistors, ferrite cores, and a magnetic drum, with input/output on perforated paper tape. It could be used in two modes: as a stored program computer or as a desk calculator. It was a micro-programmed machine, and a high-level language PAF (Programmation Automatique des Formules) was developed for it. It was launched in 1960 and over 100 were sold.
Algorithms for accuracy enhancement in a hardware logic simulator
Authors: P. Agrawal, R. Tutundjian, W. Dally
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

In this paper, we describe a hardware multiple delay logic simulator that incorporates efficient timing analyses algorithms for event cancellations, spike and race analyses and oscillation detection. The algorithms are implemented on a set of reconfigurable processors, arranged in a pipelined configuration. Spike analysis is accomplished by dynamic pulse width measurement. Both zero and non-zero delay oscillations are detected. Results of simulating industrial VLSI chips are presented to illustrate the effectiveness of the algorithms with minimal performance penalty.
A Spatial Thresholding Method for Image Segmentation
Authors: K. V. Mardia, T. J. Hainsworth
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

Several model-based algorithms for threshold selection are presented, concentrating on the two-population univariate case in which an image contains an object and background. It is shown how the main ideas behind two important nonspatial thresholding algorithms follow from classical discriminant analysis. Novel thresholding algorithms that make use of available local/spatial information are then given. It is found that an algorithm using alternating mean thresholding and median filtering provides an acceptable method when the image is relatively highly contaminated, and seems to depend less on initial values than other procedures. The methods are also applicable to multispectral k-population images.
Intelligent module for planning/control of master-dependent systems
Authors: Alex Meystel
Venue: Proceedings of the 1st international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1988)

An intelligent module is proposed in this paper which is capable of performing a joint recursive planning/control operation which propagates through the intelligent module at all planning/control levels simultaneously. Each of the actuators is equipped by an intelligent module, and all of these modules are working independently and concurrently. The model of the world is being constantly updated based upon vision and a multiplicity of other available sensors, and at various resolutions is submitted to each of the intelligent modules as applied to particular properties of the link being controlled by this module. Together these intelligent modules are working as a team of the actuators controllers, and all decisions are constantly negotiated among the members of the team. Each of the resolutional levels within the actuator intelligent modules is using the following set of planning/control tools: learning rule base, learning heuristic search, and situational decision generator which are first applied simultaneously, and then one of them takes over. A neural network is collecting information about the progress and the results of planning/control processes, and is modifying heuristics, as well as enriching the system of rules. The same neural network is used for supplying the provisional analytical model required for the lowest levels of execution control. Provisional analytical models are applied in a simple form which allows for simple real-time controller operation, and the parameters of this provisional model are constantly being updated by the neural network.
Design of Knowledge-Based Systems with a Knowledge-Based Assistant
Authors: E. Schoen, R. G. Smith, B. G. Buchanan
Venue: IEEE Transactions on Software Engineering (1988)

The authors propose a model for an intelligent assistant to aid in building knowledge-based systems (KBSs) and discuss a preliminary implementation. The assistant participates in KBS construction, including acquisition of an initial model of a problem domain, acquisition of control and task-specific inference knowledge, testing and validation, and long-term maintenance of encoded knowledge. The authors present a hypothetical scenario in which the assistant and a KBS designer cooperate to create an initial domain model and then discuss five categories of knowledge the assistant requires to offer such help. They discuss two software technologies on which the assistant is based: an object-oriented programming language, and a user-interface framework.