ppxscal/embedding_network huggingface dataset:
Constraint-Based Automatic Test Data Generation
Authors: Richard A. DeMillo, A. Jefferson Offutt
Venue: IEEE Transactions on Software Engineering (1991)

A novel technique for automatically generating test data is presented. The technique is based on mutation analysis and creates test data that approximate relative adequacy. It is a fault-based technique that uses algebraic constraints to describe test cases designed to find particular types of faults. A set of tools (collectively called Godzilla) that automatically generates constraints and solves them to create test cases for unit and module testing has been implemented. Godzilla has been integrated with the Mothratesting system and has been used as an effective way to generate test data that kill program mutants. The authors present an initial list of constraints and discuss some of the problems that have been solved to develop the complete implementation of the technique.
Strategies for distributed search
Authors: Michael A. Bauer, Tong Wang
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

The problem of locating information among cooperating agents within a distributed computing environment is considered. Such collections of agents can be collectively thought of as a single distributed application providing a single set of services; the X.500 distributed directory is an example of such an application. A central problem in such applications is the cooperative search for certain information which might be located at one of the agents. One approach to this problem relies on flooding messages throughout the distributed environment, such as that which might be used in routing algorithms to locate entries. Although the use of such algorithms, in principle, takes advantage of reaching many different agents via parallel data communication paths, the additional number of messages may be a distinct disadvantage in &ldquo;higher layer&rdquo; applications. This paper presents a variant of such approaches which rely on a depth-first method of distributing messages. Results of simulations illustrating the savings in messages of this approach to one relying on traditional flooding are presented for different network configurations.
An analysis of the Neal Nelson Business Benchmark
Authors: H. Reza Taheri
Venue: ACM SIGMETRICS Performance Evaluation Review (1990)

The Neal Nelson Business Benchmark is an industry-standard benchmark which is used to evaluate the performance of UNIX computer systems. The Business Benchmark purports to give the user an idea of the performance of the machine under real business UNIX workloads. In this article we will show that the Business Benchmark stresses few components of the system with very simple tests. As such it is more suited as a component level benchmark or users who want to focus on the performance of a particular aspect of the system, rather then a system-level UNIX benchmark representative of commercial applications.
Alternative implementations of two-level adaptive branch prediction
Authors: Tse-Yu Yeh, Yale N. Patt
Venue: ACM SIGARCH Computer Architecture News (1992)

As the issue rate and depth of pipelining of high performance Superscalar processors increase, the importance of an excellent branch predictor becomes more vital to delivering the potential performance of a wide-issue, deep pipelined microarchitecture. We propose a new dynamic branch predictor (Two-Level Adaptive Branch Prediction) that achieves substantially higher accuracy than any other scheme reported in the literature. The mechanism uses two levels of branch history information to make predictions, the history of the last k branches encountered, and the branch behavior for the last s occurrences of the specific pattern of these k branches. We have identified three variations of the Two-Level Adaptive Branch Prediction, depending on how finely we resolve the history information gathered. We compute the hardware costs of implementing each of the three variations, and use these costs in evaluating their relative effectiveness. We measure the branch prediction accuracy of the three variations of two-Level Adaptive Branch Prediction, along with several other popular proposed dynamic and static prediction schemes, on the SPEC benchmarks. We show that the average prediction accuracy for Two-Level Adaptive Branch Prediction is 97 percent, while the other known schemes achieve at most 94.4 percent average prediction accuracy. We measure the effectiveness of different prediction algorithms and different amounts of history and pattern information. We measure the costs of each variation to obtain the same prediction accuracy.
CLIM: the Common Lisp interface manager
Authors: Scott McKay
Venue: Communications of the ACM (1991)

The essence of an application is a set of objects and a set of operations on those objects. The essence of the behavior of an application's user interface is similar to Lisp's read-eval-print loop: the user specifies what he or she wants to do (perhaps via a menu or a dialog or a direct manipulation), the application performs the operation, and then the result of that operation is displayed. The Common Lisp Interface Manager (CLIM) is a system for constructing portable users interfaces in a way that directly connects the objects and operations of an application to the objects of its user interface.
Scientific visualization: viewpoint on collaborations of art, science, and engineering
Authors: Marsha E. Jessup
Venue: ACM SIGBIO Newsletter (1992)

Different perspectives on scientific visualization exist. How it is being defined, the human factors constraining its progress, perspectives of those involved in the activity, and the scientific research it facilitates are but a few of the questions to which there seems to be as many different answers as the number of individuals being asked. To clarify some of the issues, as they relate to the biomedical sciences, an examnation of the makeup of some of the more successful groups involved in the activity is undertaken, and examples of some of the imagery are provided. Both geometry-based computer graphics and numerically-based imaging techniques are discussed.
Concurrency + modularity + programmability = MARS
Authors: Vadim E. Kotov
Venue: Communications of the ACM (1991)

Modern, and particularly upcoming, technology makes it possible to design concurrent computers with a wide variety of architectures. The spectrum of applications requiring high-performance computer systems is also constantly growing. One might expect these two factors to cause a significant portion of the computer market to turn away from the traditional general-purpose mainframes in favor of the more diversified specialized proprietary machines. However, economic factors, production problems and maintenance and portability of software steer computer architects toward further unification and standardization of the design principles and components, and toward minimizing the number of proprietary computers.
Clustering Without a Metric
Authors: Geoffrey Matthews, James Hearne
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

A methodology for clustering data in which a distance metric or similarity function is not used is described. Instead, clusterings are optimized based on their intended function: the accurate prediction of properties of the data. The resulting clustering methodology is applicable, without further ad hoc assumptions or transformations of the data, (1) when features are heterogeneous (both discrete and continuous) and not combinable, (2) where some data points have missing feature values, and (3) where some features are irrelevant, i.e. have large variance but little correlation with other features. Further, it provides an integral measure of the quality of the resulting clustering. A clustering program, RIFFLE, has been implemented in line with this approach, and experiments with synthetic and real data show that the clustering is, in many respects, superior to traditional methods.
A bibliography on performance issues ATM networks
Authors: I. Nikloaidis, Raif O. Onvural
Venue: ACM SIGCOMM Computer Communication Review (1992)

The Asynchronous Transfer Mode (ATM) is the transport mode of choice for B-ISDN. In order for high speed networks to become a reality, a number of performance issues has to be resolved. In recent years, there has been a growing interest in the literature in developing performance models to explore a wide range of performance problems varying from understanding the performance of a switch architecture to implementing efficient congestion control mechanisms and light weight transport protocols. In this paper, we briefly discuss various performance problems that arise in ATM networks and provide a bibliography of related papers reported in the literature.
A rapid match algorithm for continuous speech recognition
Authors: Laurence S. Gillick, Robert Roth
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

This paper describes an algorithm for performing rapid match on continuous speech that makes it possible to recognize sentences from an 842 word vocabulary on a desktop 33 megahertz 80486 computer in near real time. This algorithm relies on a combination of smoothing and linear segmentation together with the notion of word start groups. It appears that the total computation required grows more slowly than linearly with the vocabulary size, so that larger vocabularies appear feasible, with only moderately enhanced hardware. The rapid match algorithm described here is closely related to the one that is used in DragonDictate, Dragon's commercial 30,000 word discrete utterance recognizer.
Fast search algorithms for connected phone recognition using the stochastic segment model
Authors: V. Digalakis, M. Ostendorf, J. R. Rohlicek
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

In this paper we present methods for reducing the computation time of joint segmentation and recognition of phones using the Stochastic Segment Model (SSM). Our approach to the problem is twofold: first, we present a fast segment classification method that reduces computation by a factor of 2 to 4, depending on the confidence of choosing the most probable model. Second, we propose a Split and Merge segmentation algorithm as an alternative to the typical Dynamic Programming solution of the segmentation and recognition problem, with computation savings increasing proportionally with model complexity. Even though our current recognizer uses context-independent phone models, the results that we report on the TIMIT database for speaker independent joint segmentation and recognition are comparable to that of systems that use context information.
PALACE: a layout generator for SCVS logic blocks
Authors: Knut M. Just, Edgar Auer, Werner L. Schiele, Alexander Schwaferts
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

A novel approach to the automatic layout synthesis of dynamic CMOS circuits is presented. A set of logic expressions is realized in a row of cells. Taking multi-level Boolean expressions as input, logic transistors are placed and routed. Efficient solutions are achieved by permuting the variables of the expressions and by row folding. The layout is designed on a coarse grid taking timing requirements into account and afterwards adapted to the geometric design rules by a compactor. A comparison to handcrafted layouts shows that the results of PALACE are nearly equivalent. At the same time the design productivity is increased significantly.
Massively parallel computational methods in light scattering by small particles
Authors: David J. Potter, Marhall P. Cline
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

Algorithms suitable for use on parallel computers are being developed to simulate the scattering and absorption of light by small penetrable objects such as ice crystals and biological cells. The solution of the problem is based on a geometrical optics approach. Each incident ray undergoes multiple reflections and refractions as it travels through the scattering object. Since the interactions of each incident ray are independent of those of all other rays, parallel computer architectures can be used in an efficient manner. Data parallel algorithms have been developed which assign one processor to each incident ray. A massively parallel architecture consisting of 64K processors (the Connection Machine) is being used. This means that the scattering calculations for over 65,000 rays can be carried out simultaneously. Using a stochastic approach, a Monte Carlo technique is used whereby each ray is either reflected or refracted based on probabilities. The object is represented by a collection of small facets enabling almost any shaped object or objects to be modeled from any orientation.
Fault-Tolerant Clock Synchronization in Distributed Systems
Authors: Parameswaran Ramanathan, Kang G. Shin, Ricky W. Butler
Venue: Computer (1990)

Existing fault-tolerant clock synchronization algorithms are compared and contrasted. These include the following: software synchronization algorithms, such as convergence-averaging, convergence-nonaveraging, and consistency algorithms, as well as probabilistic synchronization; hardware synchronization algorithms; and hybrid synchronization. The worst-case clock skews guaranteed by representative algorithms are compared, along with other important aspects such as time, message, and cost overhead imposed by the algorithms. More recent developments such as hardware-assisted software synchronization and algorithms for synchronizing large, partially connected distributed systems are especially emphasized.
A security risk of depending on synchronized clocks
Authors: Li Gong
Venue: ACM SIGOPS Operating Systems Review (1992)

Many algorithms or protocols, in particular cryptographic protocols such as authentication protocols, use synchronized clocks and depend on them for correctness. This note describes a scenario where a clock synchronization failure renders a protocol vulnerable to an attack even after the faulty clock has been resynchronized. The attack exploits a postdated message by first suppressing it and replaying it later.
A closed form for Datalog queries with integer order (preliminary version)
Authors: Peter Z. Revesz
Venue: Proceedings of the third international conference on database theory on Database theory (1990)

The use of constraints within logic programming and within database languages promises interesting new applications. We show that Datalog queries with simple integer order constraints can be evaluated bottom-up in closed form over generalized databases.
A survey of software functional testing methods
Authors: A. A. Omar, F. A. Mohammed
Venue: ACM SIGSOFT Software Engineering Notes (1991)

Functional testing is used to find disagreement between the specifications and the actual implementation of the software systems. The method of representing the specification can help to detect inconsistency and incompleteness in it. The various specification representation schemes are outlined in the paper. The basic technique of functional testing of software systems is the black box technique. This technique generates the test data using the information contained in the program's specification, independent of the implemented program's code. Black box testing cannot discover errors contained in the functions which are not mentioned explicitly in the specification. Therefore, a program dependent testing is necessary to discover this type of errors. The paper surveys the different methods of generating test data for both techniques; the black box and the program dependent techniques.
A Lisp environment at IBM T J Watson Research
Authors: M. Mikelsons, C. N. Alberga, C. F. Skutt
Venue: ACM SIGPLAN Lisp Pointers (1990)

We give a brief description of a Common Lisp programming environment developed at the IBM TJ Watson Research Center over the past two years. The two most novel features of this environment are a program analysis tool and a visual stepper. These are described in more detail.
A Computationally Compact Divergence Measure for Speech Processing
Authors: Beth A. Carlson, Mark A. Clements
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

The directed divergence, which is a measure based on the discrimination information between two signal classes, is investigated. A simplified expression for computing the directed divergence is derived for comparing two Gaussian autoregressive processes such as those found in speech. This expression alleviates both the computational cost (reduced by two thirds) and the numerical problems encountered in computing the directed divergence. In addition, the simplified expression is compared with the Itakura-Saito distance (which asymptotically approaches the directed divergence). Although the expressions for these two distances closely resemble each other, only moderate correlations between the two were found on a set of actual speech data.
Probabilistic models of short and long distance word dependencies in running text
Authors: Julien Kupiec
Venue: Proceedings of the workshop on Speech and Natural Language (1989)

This article describes two complementary models that represent dependencies between words in local and non-local contexts. The type of local dependencies considered are sequences of part of speech categories for words. The non-local context of word dependency considered here is that of word recurrence, which is typical in a text. Both are models of phenomena that are to a reasonable extent domain independent, and thus are useful for doing prediction in systems using large vocabularies.
Optimistic Make (Software Design)
Authors: Rick Bubenik, Willy Zwaenepoel
Venue: IEEE Transactions on Computers (1992)

The notion of encapsulations is introduced as the basic construct used to support optimistic make (a software tool). The authors describe the implementation of optimistic make in the V-System on a collection of SUN workstations. Statistics measured from this implementation are used to synthesize a workload for a discrete-event simulation, and to validate the simulation's results. The simulation shows a speedup distribution over pessimistic make with a median of 1.72 and a mean of 8.28. The speedup distribution is strongly dependent on the ratio between the target out-of-date times and the command execution times. With faster machines the median of the speedup distribution grows to 5.1, and then decreases again.
A retargetable compiler for ANSI C
Authors: Christopher W. Fraser
Venue: ACM SIGPLAN Notices (1991)

lcc is a new retargetable compiler for ANSI C. Versions for the VAX, Motorola 68020, SPARC, and MIPS are in production use at Princeton University and at AT amp;T Bell Laboratories. With a few exceptions, little about lcc is unusual --- it integrates several well engineered, existing techniques --- but it is smaller and faster than most other C compilers, and it generates code of comparable quality, lcc's target-independent front end performs a few simple, but effective, optimizations that contribute to good code; examples include simulating register declarations and partitioning switch statement cases into dense tables. It also implements target-independent function tracing and expression-level profiling.
A comprehensive analytical model for garbage collection algorithms
Authors: Jürgen Heymann
Venue: ACM SIGPLAN Notices (1991)

We present an analytical model that allows to compare all known garbage collection (GC) algorithms w.r.t. various performance measures. The overhead functions are natural and accurate; natural in the sense that they are given in terms of easy to measure and tune parameters, accurate in the sense that they account for all relevant sources of time and space overhead of the different algorithms. Space overhead accounted for includes mark bits, mark stack, reference count bits/tables, entry tables for area-GC, object tables etc. as well as storage fragmentation. Time overhead components are e.g. time to mark/scan/copy nodes, update reference counts, check for forwarding pointers, synchronization costs etc.
A supplement to sampling-based methods for query size estimation in a database system
Authors: Yibei Ling, Wei Sun
Venue: ACM SIGMOD Record (1992)

Sampling-based methods for estimating relation sizes after relational operators such as selections, joins and projections have been intensively studied in recent years. Methods of this type can achieve high estimation accuracy and efficiency. Since the dominating overhead involved in a sampling-based method is the sampling cost, different variants of sampling methods are proposed so as to minimize the sampling percentage (thus reducing the sampling cost) while maintaining the estimation accuracy in terms of the confidence level and relative error (to be precisely defined later in Section 2). In order to determine the minimal sampling percentage, the overall characteristics of the data such as the mean and variance are needed. Currently, the representative sampling-based methods in literature are based on the assumption that overall characteristics of data are unavailable, and thus a significant amount of effort is dedicated to estimating these characteristics so as to approach the optimal (minimal) sampling percentage. The estimation for these characteristics incurs cost as well as suffers the estimation error. In this short essay, we point out that the exact values of these characteristics of data can be kept track of in a database system at a negligible overhead. As a result, the minimal sampling percentage while ensuring the specified relative error and confidence level can be precisely determined.
Optimal Edge Detectors for Ramp Edges
Authors: Maria Petrou, Josef Kittler
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

It is argued that the best way to model an edge is by assuming all ideal mathematical function passed through a low-pass filter and and immersed in noise. Using techniques similar to those developed by J. Canny (1983, 1986) and L.A. Spacek (1986), optimal filters are derived for ramp edges of various slopes. The optimal nonrecursive filter for ideal step edges is then derived as a limiting case of the filters for ramp edges. Because there are no step edges in images, edge detection is improved when the ramp filter is used instead of the filters developed for step edges. For practical purposes, some convolution masks are given which can be used directly for edge detection without the need to go into the details of the subject.
The computation of normalizers in permutation groups
Authors: D. F. Holt
Venue: Journal of Symbolic Computation (1991)

We describe the theory and implementation of an algorithm for computing the normalizer of a subgroup H of a group G, where G is defined as a finite permutation group. The method consists of a backtrack search through the elements of G, with a considerable number of tests for pruning branches of the search tree.