ppxscal/embedding_network huggingface dataset:
On planning assemblies
Authors: B. K. Natarajan
Venue: Proceedings of the fourth annual symposium on Computational geometry (1988)

This paper concerns the problem of assembling composite objects. We study the problem on two fronts; Firstly we study the complexity of deciding the existence of an assembly sequence and show that this is PSPACE-hard in general. Secondly we define a new measure of complexity, one that attempts to measure the minimum number of hands required to assemble a given composite. We analyze various classes of composite objects with respect to this measure.
The mythical task
Authors: Chris Hallgren
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1990)

We confront a time in society when phrases such as &ldquo;information anxiety&rdquo; have become cliches. As documentation developers, we have a mission to sort information into structures that help users perform their work on computers. Task-based documentation has emerged as one of the most popular models for explaining the principals of sorting information into useful instructions or learning materials. This paper deals with environments where standard task-analysis flounders, either due to the conflicts between different audiences who use the same task elements in different ways, or the complexity of the domain, which makes discrete task modules nearly impossible to define. Under these conditions, we equate the definition of clear tasks with myth -- meaning a symbolic goal more than a real possibility. This paper will explore ways to track down the mythical tasks in the information that describes a large, open computer graphics system. This discussion will also serve as a model for analyzing the use of open systems. First we supply the technological history that has led to this information breakdown. Then we present two models from the computer graphics field to use as examples in the application of the theories in this paper. Following this, the paper discusses Tour Books, Tool Books, Job Books, and the importance of both precise and alternate terminology. Finally, it will discuss the usefulness and limitations of indexes, cross references, alphabetic references and hyper text (extended indexes and cross references).
A Compiler that Increases the Fault Tolerance of Asynchronous Protocols
Authors: B. A. Coan
Venue: IEEE Transactions on Computers (1988)

A compiler that increases the fault tolerance of certain asynchronous protocols is presented. Specifically, it transforms a source protocol that is resilient to crash faults into an object protocol that is resilient to Byzantine faults. The compiler simplifies the design of protocols for the Byzantine fault model because it allows the design process to be broken in two steps. The first step is to design a protocol for the crash fault model. The second step, which is completely mechanical, is to compile the protocol into one for the Byzantine fault model. The compiler is used to produce an asynchronous approximate agreement protocol that operates in the Byzantine fault model and improves in several respects on the performance of the asynchronous approximate agreement protocol of D. Dolev et al. (1986).
A simulation study of two-level caches
Authors: R. T. Short, H. M. Levy
Venue: ACM SIGARCH Computer Architecture News (1988)

We report on a trace-driven simulation study to examine the effect of a two-level cache hierarchy in uniprocessors. A simulation model of a multiple-cycle-per-instruction processor was constructed to estimate the total cycles required to execute a synthetic benchmark. Results show that a second-level cache can be used to increase system performance when main memory access times are large relative to CPU cycle time. For example, the addition of a 4-cycle, 64K second-level cache following a 1-cycle, 8K first-level cache increases performance by 15 percent when used in a system with a 15-cycle primary memory. Second level caches are shown to be particularly effective when used behind small on-chip caches; adding an 8K second-level to a 1K first-level increases performance by 26 percent, assuming similar parameters. We also evaluate the performance impact of different write strategies and separate I and D caches.
Unified Approach for Early-Phase Image Understanding Using a General Decision Criterion
Authors: D. S. Jeong, P. M. Lapsa
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

Two types of approaches for computer vision are combined to model images or portions thereof, parametrically. These approaches, namely those based on polynomial models and those based on random-field models, are combined based on a general decision criterion for dealing with a variety of modeling strategies. Selection among alternative model structures is in accordance with the tradeoff between sample size and model complexity. Experiments with synthesized images and natural images such as Brodatz textures illustrate some identification and segmentation uses of this unified approach. The implemented segmentation algorithm achieves early-phase region extraction without relying on any contextual or high-level assumptions. A natural result of this is a list of regions, suitable as input for higher-level stages of image understanding in addition to a pixel-labeled image.
A multicast transport protocol
Authors: J. Crowcroft, K. Paliwoda
Venue: Symposium proceedings on Communications architectures and protocols (1988)

This paper presents the design of a reliable multicast transport protocol. The aim of the protocol is to provide a service equivalent to a sequence of reliable sequential unicasts between a client and a number of servers, whilst using the broadcast nature of some networks to reduce both the number of packets transmitted and the overall time needed to collect replies. The service interface of the protocol offers several types of service, ranging from the collection of a single reply from any one of a set of servers to the collection of all replies from all known servers. The messages may be of effectively arbitrary size, and the number of servers may be quite large. To support this service over real networks, special flow control mechanisms are used to avoid multiple replies overrunning the client. Reliable delivery is ensured using timeouts and a distributed acknowledgement scheme. The protocol is implemented over a network layer which support multicast destination addressing and packet delivery. The behaviour of the protocol over both LANs and LANs interconnected by WAN lines is discussed. We also include some notions for possible future support from network interface hardware.
Network Resilience: A Measure of Network Fault Tolerance
Authors: Walid Najjar, Jean-Luc Gaudiot
Venue: IEEE Transactions on Computers (1990)

A probabilistic measure of network fault tolerance expressed as the probability of a disconnection is proposed. Qualitative evaluation of this measure is presented. As expected, the single-node disconnection probability is the dominant factor irrespective of the topology under consideration. The authors derive an analytical approximation to the disconnection probability and verify it with a Monte Carlo simulation. On the basis of this model, the measures of network resilience and relative network resilience are proposed as probabilistic measures of network fault tolerance. These are used to evaluate the effects of the disconnection probability on the reliability of the system.
The C Information Abstraction System
Authors: Yih-Farn Chen, Michael Y. Nishimoto, C. V. Ramamoorthy
Venue: IEEE Transactions on Software Engineering (1990)

A system for analyzing program structures is described. The system extracts relational information from C programs according to a conceptual model and stores the information in a database. It is shown how several interesting software tasks can be performed by using the relational views. These tasks include generation of graphical views, subsystem extraction, program layering, dead code elimination and binding analysis.
Information structures in language directed architectures
Authors: R. Katti, L. Manwaring
Venue: Proceedings of the 22nd annual workshop on Microprogramming and microarchitecture (1989)

Only recently has the design of computer architectures deviated from the Von Neumann style. Most architectures based on the Von Neumann architecture suffer from what is called 'the semantic gap'. This means that the objects and operations in a high level language (HLL) are not closely related to the objects and operations in the architectures that execute the HLL [1]. This paper addresses the issues involved in the semantic gap problem, by formulating a framework based on 'information structures' that would aid in the design of HLL architectures. First digital computers are defined based on 'information structures'. Execution of a program in an HLL is defined in terms of transformations on information structures. An architecture design methodology is proposed and some comments about performance are made. Finally different ways of implementing information structures are considered.
The use of bottleneck starvation avoidance with queue predictions in shop floor control
Authors: C. R. Glassey, R. G. Petrakian
Venue: Proceedings of the 21st conference on Winter simulation (1989)

The accurate estimation of lead times and the use of factory-wide information can improve the performance of dynamic shop floor control. This paper presents a dispatching policy that is based on the concept of bottleneck starvation avoidance and relies on frequently updated queue predictions for all workstations. The queue predictions are used to dynamically estimate the lead times required for lots to reach workstations on their routes, particularly the bottleneck workstation. Object-oriented simulation experiments were run for several wafer fab configurations with results showing a consistantly good behavior of the computationally intensive control mechanism presented here.
Adaptive information retrieval: using a connectionist representation to retrieve and learn about documents
Authors: R. K. Belew
Venue: ACM SIGIR Forum (1989)

AIR represents a connectionist approach to the task of information retrieval. The system uses relevance feedback from its users to change its representation of authors, index terms and documents so that, over time, AIR improves at its task. The result is a representation of the consensual meaning of keywords and documents shared by some group of users. The central focus goal of this paper is to use our experience with AIR to highlight those characteristics of connectionist representations that make them particularly appropriate for IR applications. We argue that this associative representation is a natural generalization of traditional IR techniques, and that connectionist learning techniques are effective in this setting.
Task-Level Planning of Pick-and-Place Robot Motions
Authors: T. Lozano-Pérez, E. Mazer, J. L. Jones, P. A. O'Donnell
Venue: Computer (1989)

A task-level robot system named Handey, which is under development, is described. The current system is limited to pick-and-place operations, and it has successfully carried out dozens of such operations involving a variety of parts in relatively complex environments. The pick-and-place problem is described, and approximate approaches to the problem are examined. Heuristic motion planning in Handey is then discussed.
A parsing algorithm for unification grammar
Authors: Andrew Haas
Venue: Computational Linguistics (1989)

We describe a table-driven parser for unification grammar that combines bottom-up construction of phrases with top-down filtering. This algorithm works on a class of grammars called depth-bounded grammars, and it is guaranteed to halt for any input string. Unlike many unification parsers, our algorithm works directly on a unification grammar---it does not require that we divide the grammar into a context-free "backbone" and a set of feature agreement constraints. We give a detailed proof of correctness. For the case of a pure bottom-up parser, our proof does not rely on the details of unification---it works for any pattern-matching technique that satisfies certain simple conditions.
Partial order programming (extended abstract)
Authors: D. S. Parker
Venue: Proceedings of the 16th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

We introduce a programming paradigm in which statements are constraints over partial orders. A partial order programming problem has the form minimize u subject to u1 &sqsupe; v1, u2 &sqsupe; v2, &middot;&middot;&middot; where u is the goal, and u1 &sqsupe; v1, u2 &sqsupe; v2, &middot;&middot;&middot; is a collection of constraints called the program. A solution of the problem is a minimal value for u determined by values for u1, v1, etc. satisfying the constraints. The domain of values here is a partial order, a domain D with ordering relation &sqsupe;. The partial order programming paradigm has interesting properties: It generalizes mathematical programming and also computer programming paradigms (logic, functional, and others) cleanly, and offers a foundation both for studying and combining paradigms. It takes thorough advantage of known results for continuous functionals on complete partial orders, when the constraints involve expressions using only continuous and monotone operators. The semantics of these programs coincide with recent results on the relaxation solution method for constraint problems. It presents a framework that may be effective in modeling, or knowledge representation, of complex systems.
GTS: parallelization and vectorization of tight recurrences
Authors: E. Ayguadé, J. Labarta, J. Torres, P. Borensztejn
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

In this paper we present a new method for extracting the maximum parallelism or vector operations out of DO loops with tight recurrences using sequential programming languages. We have named the method Graph Traverse Scheduling (GTS). It is devised to produce code for shared memory multiprocessors or vector machines. When parallelizing, hardware support for fast synchronization is assumed. The method is presented for single nested loops including one or several recurrences and we show how parallel and vector code is generated. Based on the dependence graph of a loop, we first evaluate its parallelism and vector length of statements. Then we apply GTS to distribute loop iterations between tasks or to generate vector operations of a given length. When this method is applied for parallel code generation, dependencies not included in the sequential execution of each task must be explicitly synchronized. A method to minimize the number of explicit synchronizations is also presented. We also present how to compute the synchronization-free parallelism obtaining fully independent tasks. When GTS is applied for vector code generation, a sequential loop of vector operations is obtained.
A fast Las Vegas algorithm for triangulating a simple polygon
Authors: K. L. Clarkson, R. E. Tarjan, C. J. Van Wyk
Venue: Proceedings of the fourth annual symposium on Computational geometry (1988)

We present an algorithm that triangulates a simple polygon on n vertices in &Ogr;(n log* n) expected time. The algorithm uses random sampling on the input, and its running time does not depend on any assumptions about a probability distribution from which the polygon is drawn.
On Liouvillian solutions of homogeneous linear differential equations
Authors: F. Ulmer, J. Calmet
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

This paper deals with the problem of finding Liouvillian solutions of an nth order homogeneous linear differential equation L(y)=0 with coefficients in a differential field k whose field of constants is C. For second order linear differential equations such an algorithm has been given by J. Kovacic and implemented. A general decision procedure for finding Liouvillian solutions of nth order equations has been given by M.F. Singer, but the resulting algorithm, although constructive, is not in implementable form even for second order equations. The algorithm uses the fact that, if L(y)=0 has a Liouvillian solution, then, L(y)=0 has a solution z such that u=z&prime;/z is algebraic over k, which means that L(y) has a solution z of the form e&int;u, where u is algebraic over k. Since the logarithmic derivative u=z&prime;/z of a solution z is a solution of the Riccati equation R(y)=0 associated to L(y)=0, the problem thus reduces to find an algebraic solution u of R(y)=0. This task is now split into two parts: to find the set DEG(n) of possible degrees N for the minimal polynomial P(x)=0 of u over k. to compute, for each possible degree of P(x), the possible coefficients of P(x). If we denote c(ii) the complexity of the second step and #DEG(n) the size of the set DEG(n), we see that the complexity of the whole procedure is of the form c(ii)#DEG(n) and thus exponential in #DEG(n). This shows that the only way to make the procedure effective is to get sharp bounds on the size of the set DEG(n), which is the scope of this paper. Initially, we construct, using representation theory of linear groups, a set DEG(n) where all N are of bounded size and only divisible by a small set of primes. Because of the divisibility condition the size of the set DEG(n) is asymptotically small. We derive the upper bound 2n4&middot;&pgr;(n+1) for #DEG(n), where n is the degree of L(y)=0 and &pgr;(n) denotes the number of primes less or equal to n. This improves the bound of #DEG(n) from Jordan's theorem. The bound on the size of the primes that divide N is also a bound for the primes that divide the algebraic degree of the logarithmic derivative of at least one solution of L(y)=0. From the conditions on the size of the primes, some structure of the differential galois group can also be derived. Next, we study the action of the differential galois group on u to get sharp bounds for #DEG(n). The resulting set DEG(n) is the best possible one for n=2 and probably small enough to allow an implementation of the Singer-algorithm for n=3. We show that, for an algebraic solution u of R(u)=0, the degree N of the minimal polynomial P(x) of u equals the size of the orbit of u under the action of the differential galois group of L(y)=0. We then bound the size of the orbit of u by a value that can be effectively computed from a classification of the finite subgroups of PGL(n,C).
Complexity of factoring and calculating the GCD of linear ordinary differential operators
Authors: D. Yu. Grigor'ev
Venue: Journal of Symbolic Computation (1990)

Let L=@?0@?k@?n(f"k/f)d^kd^kx be a linear differential operator with rational coefficients, where f"k,f@?@?@?[X] and @?@? is the field of algebraic numbers. Let deg@?"x(L)=max@?0@?k@?n{deg@?"x(f"k),deg@?"x(f)} and let N be an upper bound on deg"x(L"j) for all possible factorizations of the form L = L"1 L"2 L"3, where the operators L"j are of the same kind as L and L"2, L"3, are normalized to have leading coefficient 1. An algorithm is described that factors L within time (N @?)^0^(^n^^^4^) where @? is the bit size of L. Moreover, a bound N @? exp((@?2^n)^2^n) is obtained. We also exhibit a polynomial time algorithm for calculating the greatest common (right) divisor of a family of operators.
Conceptual graphs as a visual language for knowledge acquisition in architectural expert systems
Authors: L. F. Pau, S. S. Nielsen
Venue: Issue 108 (April 1989) (1989)

The EKSPRO expert system on PC/AT is based on a 3-D CAD system (Scribe modeller), linked to a solar irradiation calculation package (Sun Code), to PASCAL material and equipment data bases, and to a Prolog II based inference engine. It allows architects to revise office room shapes, materials, lighting sources, thermal control devices, window locations and sizes. Building engineers can select the same specifically for a given design, in view of thermal comfort requirements (daily temperature variation ranges), energy consumption requirements, and building regulations (see also [1] [2]). Needless to say, the above involves extensive knowledge acquisition by tapping off architects for architectural selection rules, and engineers for compliance constraints, both represented as attributed conceptual graphs. The approach below was found extremely useful by allowing for elicitation from examples (cases of special office designs) but also from design principles.
Embedding Rectangular Grids into Square Grids with Dilation Two
Authors: Rami G. Melhem, Ghil-Young Hwang
Venue: IEEE Transactions on Computers (1990)

A novel technique, the multiple ripple propagation technique, is presented for mapping and h*w grid into a w*h grid such that the dilation cost is 2, i.e. such that any two neighboring nodes in the first grid are mapped onto two nodes in the second grid that are separated by a distance of at most 2. The technique is then used as a basic tool for mapping any rectangular source grid into a square target grid with the dilation two property preserved. The ratio of the number of nodes in the source grid to the number of nodes in the target grid, called the expansion cost, is shown to be always less than 1.2. This is a significant improvement over the previously suggested techniques, where the expansion cost could be bounded by 1.2 only if the dilation cost was allowed to be as high as 18.
Parallel Testing for Pattern-Sensitive Faults in Semiconductor Random-Access Memories
Authors: P. Mazumder, J. K. Patel
Venue: IEEE Transactions on Computers (1989)

A design strategy is presented for efficient and comprehensive parallel testing of high-density, MOS random-access memories (RAMs). Parallel test algorithms for RAMs have been developed on the basis of this design-for-testability approach for a broad class of pattern-sensitive faults. Two algorithms which are significantly more efficient than previous approaches are examined. The first algorithm detects the static and dynamic pattern-sensitive faults over a neighborhood of five cells. The second algorithm tests the symmetric pattern-sensitive faults over a neighborhood of nine cells. It tests an n-bit RAM organized as a square root n* square root n array in 97 square root n memory cycles. The design-for-testability approach modifies the existing RAM architecture very little, so that it can be implemented very easily. The additional overhead is only about 2 square root n transistors. The low overhead allows high reliability, and the additional circuit for each bit line can fit within the 3 lambda -to-6 lambda pitch width in a high-density, single-transistor dynamic RAM. Although the algorithm is designed to detect pattern-sensitive faults, the modified architecture can be readily used to speed up other conventional algorithms of linear complexity by a factor of O( square root n).
Validating Halstead's Theory for Pascal Programs
Authors: L. Felician, G. Zalateu
Venue: IEEE Transactions on Software Engineering (1989)

M.H. Halstead's theory (1977) has been validated for different languages, but Pascal programs seem to fit only partially with the theory. D.B. Johnston and A.M. Lister (1981) first recognized the lack of operators due to the structure of this language and proposed a modification of Halstead's formula. The article confirms their results but suggests a correction to their formula, which is particularly necessary for large programs. Experimental results, obtained by examining about 550 Pascal programs, represent the widest test to date of Halstead theory with regard to Pascal programs.
CASE productivity perceptions of software engineering professionals
Authors: Ronald J. Norman, Jay F. Nunamaker,  Jr.
Venue: Communications of the ACM (1989)

Computer-aided software engineering (CASE) is moving into the problem-solving domain of the systems analyst. The authors undertook a study to investigate the various functional and behavioral aspects of CASE and determine the impact it has over manual methods of software engineering productivity.