ppxscal/embedding_network huggingface dataset:
Information Resources Management in Heterogeneous, Distributed Environments: A Metadatabase Approach
Authors: Cheng Hsu, M'hamed Bouziane, Laurie Rattner, Lester Yee
Venue: IEEE Transactions on Software Engineering (1991)

The core structure of a metadatabase system for information integration in heterogeneous and distributed environments, the global information resources dictionary (GIRD) model for unified metadata representation and management (both data and knowledge), is discussed. Overviews of metadatabase systems and the two-stage entity relationship (TSER) representation method are presented. To illustrate some major properties of the metadatabase model, and to show how the GIRD elements fit together to deliver these properties, manufacturing information management examples are given. The GIRD and the information resources dictionary system (IRDS) standard are compared.
On the semantic equivalence of heterogeneous representations in multimodel multidatabase systems
Authors: Dipayan Gangopadhyay
Venue: ACM SIGMOD Record (1991)

We present in this paper an extensible metalevel system, called M(DM), in which the syntax and the semantics of data models, schemas, and databases can be uniformly described. We show with examples how to derive in M(DM) the semantic equivalence (or lack thereof) of symbols across different reresentation systems. We argue that, because of the inherent incompleteness of legacy databases, semantic equivalence must in general be ascertained by additional a posteriori assertions that are external to the representation under consideration.
A course in software portability
Authors: James D. Mooney
Venue: Proceedings of the twenty-third SIGCSE technical symposium on Computer science education (1992)

This paper describes an experimental course on the topic of software portability, and initial experience in teaching this course. With the continuing proliferation of both applications and computing environments, the need for portability is being increasingly recognized. A large proportion of the software now being developed will eventually need to be ported to new environments. Yet this topic is missing from most computer science and software engineering curricula. The course described here was designed to explore practical issues in the development of portable software. Lectures and discussions on portability topics are combined with the ongoing development of a simple software project designed to expose a variety of portability problems. During the course the project is ported to several environments and redesigned to improve its portability. This course has been taught experimentally with encouraging results. Student assignments have used novel and effective methods to overcome portability barriers. Feedback from student indicates that they have become more aware of portability issues to be considered in software development, and have gained experience with system interface issues in several programming environments.
Parameterised compression for sparse bitmaps
Authors: Alistair Moffat, Justin Zobel
Venue: Proceedings of the 15th annual international ACM SIGIR conference on Research and development in information retrieval (1992)

Full-text retrieval systems often use either a bitmap or an inverted file to identify which documents contain which terms, so that the documents containing any combination of query terms can be quickly located. Bitmaps of term occurrences are large, but are usually sparse, and thus are amenable to a variety of compression techniques. Here we consider techniques in which the encoding of each bitvector within the bitmap is parameterised, so that a different code can be used for each bitvector. Our experimental results show that the new methods yield better compression than previous techniques.
Recognition by Linear Combinations of Models
Authors: Shimon Ullman, Ronen Basri
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

An approach to visual object recognition in which a 3D object is represented by the linear combination of 2D images of the object is proposed. It is shown that for objects with sharp edges as well as with smooth bounding contours, the set of possible images of a given object is embedded in a linear space spanned by a small number of views. For objects with sharp edges, the linear combination representation is exact. For objects with smooth boundaries, it is an approximation that often holds over a wide range of viewing angles. Rigid transformations (with or without scaling) can be distinguished from more general linear transformations of the object by testing certain constraints placed on the coefficients of the linear combinations. Three alternative methods of determining the transformation that matches a model to a given image are proposed.
Less complex elementary functions
Authors: Henry G. Baker
Venue: ACM SIGPLAN Notices (1992)

The "textbook" definitions of complex elementary functions---e.g., sin(z)---are usually given in terms of formulae which involve complex operations. In this paper, we give formulae for complex elementary functions in which the real and imaginary parts can be computed separately using only real operations. Many of these formulae are obvious, but some---e.g., asin(z), acos(z), atan(z), asinh(z), acosh(z), atanh(z)---are not obvious and/or not well-known.
A Highly Robust Estimator Through Partially Likelihood Function Modeling and Its Application in Computer Vision
Authors: Xinhua Zhuang, Tao Wang, Peng Zhang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

The authors present a highly robust estimator, known as the model fitting (MF) estimator for general regression. They explain that high robustness becomes possible through partially but completely modeling the unknown log likelihood function. The partial modeling takes place by taking the Bayesian statistical decision rule and a number of important heuristics into consideration while maximizing the log likelihood function. Applications include the automatic selection of multiple thresholds, single rigid motion estimation or multiple rigid motion segmentation, and estimation from two perspective views. It is believed that the proposed MF estimator will aid in solving many robust estimation problems that demand an estimator that is either highly robust or capable of handling contaminated Gaussian mixture models.
Walking an unknown street with bounded detour
Authors: Rolf Klein
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

A polygon with two distinguished vertices, s and g, is called a street if the two boundary chains from s to g are mutually weakly visible. For a mobile robot with onboard vision, a strategy for finding a short path from s to g in a street not known in advance is described, and it is proved that the length of the path created does not exceed 1+3 pi /2 times the length of the shortest path from s to g. Experiments suggest that the strategy is much better than this, as no ratio bigger than 1.8 has yet been observed. This is complemented by a lower bound of 1.41 for the relative detour each strategy can be forced to generate.
Implementation machine paradigm for parallel programming
Authors: Manohar Rao, Zary Segall, Dalibor Vrsalovic
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

Most supercomputers today are parallel computers. In this paper, an approach for efficiently mapping parallel applications onto parallel MIMD machine architectures is introduced. The applicability of this approach to uniform memory access multiprocessors is demonstrated. The paper shows that an intermediate layer of abstraction between the application level and the parallel architecture level is conducive to not only a better software productivity, but also to performance efficient programs. The intermediate layer consists of a set of commonly used parallel programming paradigms (implementation machines). A mathematical representation and a pragmatic representation are provided for each implementation machine (IM). The user maps the application on to one or a set of IMs and the system implements the IMs efficiently on the underlying parallel machine. To illustrate the power of the above concept two different ways of parallelizing a molecular dynamics algorithm (master-slave and pipeline) on a shared memory multiprocessor are presented. Mathematical models and pragmatic representations are developed for both these implementation machines. The utility of the IM approach to parallel programming is demonstrated. Students in a graduate course on parallel processing were asked to write parallel programs using the IM approach. The results of this experiment indicate that the IM approach indeed leads to performance efficient parallel programs.
An object-oriented Tower Of Babel
Authors: Michael L. Nelson
Venue: ACM SIGPLAN OOPS Messenger (1991)

Like many new ideas, object-oriented programming (OOP) does not yet have a universally accepted definition. Even the terminology of OOP can vary greatly from one system to another. One might even say that we have created something of an object-oriented 'Tower of Babel'.While it is expected that the syntax will vary from one language to another, there is no logical reason for using identical terminology in completely differently ways. If OOP is to be accepted by the computer science community in general, then it is time to put our idiosyncrasies aside and at least agree on the basics.
Test Generation for Iterative Logic Arrays Based on an N-Cube of Cell States Model
Authors: Abhijit Chatterjee, Jacob A. Abraham
Venue: IEEE Transactions on Computers (1991)

The authors present a novel approach to the test generation problem for a more general class of two-dimensional iterative logic arrays (ILAs) than considered by previous researchers. For certain ILAs it is possible to find a test set whose size remains fixed irrespective of the size of the ILA, while for others it varies with array size. Given an arbitrary ILA cell truth table and a cell interconnection structure, the goal is to determine if a fixed-size test can be found. If not, then a test set whose size grows as slowly as possible with the size of the array should be found. The authors propose a new model, called the n-cube of cell states model, for representing the cell truth table and interconnection structure. The test generation problem is shown to be related to certain properties of cycles in a set of graphs obtained from this model. By careful analysis of these cycles, efficient testing schedules can be obtained. The proposed technique can be applied to unilateral as well as regular bilateral ILAs in which the bilateral direction of signal flow are restricted to lie along the horizontal axis.
Reducing edge connectivity to vertex connectivity
Authors: Zvi Galil, Giuseppe F. Italiano
Venue: ACM SIGACT News (1991)

We show how to reduce edge connectivity to vertex connectivity. Using this reduction, we obtain a linear-time algorithm for deciding whether an undirected graph is 3-edge-connected, and for computing the 3-edge-connected components of an undirected graph.
A Four Russians algorithm for regular expression pattern matching
Authors: Gene Myers
Venue: Journal of the ACM (JACM) (1992)

Given a regular expression R of length P and a word A of length N, the membership problem is to determine if A is in the language denoted by R. An O(PN/lgN) time algorithm is presented that is based on a lgN speedup of the standard O(PN) time simulation of R's nonderministic finite automaton on A using a combination of the node-listing and &ldquo;Four-Russians&rdquo; paradigms. This result places a new worst-case upper bound on regular expression pattern matching. Moreover, in practice the method provides an implementation that is faster than existing software for small regular expressions.
A Method for Software Reliability Analysis and Prediction Application to the TROPICO-R Switching System
Authors: Karama Kanoun, Marta Rettelbusch de Bastos Martini, Jorge Moreira de Souza
Venue: IEEE Transactions on Software Engineering (1991)

An evaluation method which allows existing reliability growth models to provide better predictions of software behavior is presented. The method is primarily based on the analysis of the trend exhibited by the data collected on the program (which is determined by reliability growth tests). Reliability data are then partitioned according to the trend, and two types of reliability growth models can be applied: when the data exhibit reliability decrease followed by reliability growth, an S-shaped model can be applied, and in case of reliability growth, most of the other existing reliability growth models can be applied. The hyperexponential model is shown to allow prediction of the software residual failure rate in operation, and this failure rate is used as a qualification index for the software product. The method is illustrated through its application to the Brazilian electronic switching system TROPICO-R.
Instruction-level parallelism from execution interlock collapsing
Authors: Nadeem Malik, Richard J. Eickemeyer, Stamatis Vassiliadis
Venue: ACM SIGARCH Computer Architecture News (1992)

An innovative technique has been developed that permits the collapsing of execution interlocks between integer ALU operations as well as between address generation operations, allowing parallel execution of two instructions, having true dependencies, in a single cycle. Given that the proposed scheme has been shown not to increase the machine cycle time, it potentially provides an attractive means for increasing the instruction--level parallelism. Preliminary results show that within the basic blocks, the geometric mean of the speedup from this new design technique is up to 10% in the integer SPEC Benchmarks. The geometric mean of the speedup including floating point benchmarks is up to 6%. The results also suggest that depending on the application environment this new design may be used as an alternative to the relatively more expensive out--of--order instruction issue approach.
A model of authorization for next-generation database systems
Authors: Fausto Rabitti, Elisa Bertino, Won Kim, Darrell Woelk
Venue: ACM Transactions on Database Systems (TODS) (1991)

The conventional models of authorization have been designed for database systems supporting the hierarchical, network, and relational models of data. However, these models are not adequate for next-generation database systems that support richer data models that include object-oriented concepts and semantic data modeling concepts. Rabitti, Woelk, and Kim [14] presented a preliminary model of authorization for use as the basis of an authorization mechanism in such database systems. In this paper we present a fuller model of authorization that fills a few major gaps that the conventional models of authorization cannot fill for next-generation database systems. We also further formalize the notion of implicit authorization and refine the application of the notion of implicit authorization to object-oriented and semantic modeling concepts. We also describe a user interface for using the model of authorization and consider key issues in implementing the authorization model.
Eiffel Linda: an object-oriented Linda dialect
Authors: Robert Jellinghaus
Venue: ACM SIGPLAN Notices (1990)

Eiffel is a statically-typed object-oriented language which supports good software engineering techniques but provides no support for concurrency; Linda is a parallel programming model which provides a uniform semantics for coordination and communication among multiple processes. This paper describes an Eiffel Linda which injects the Linda operations into the Eiffel language. The resulting synthesis extends both Eiffel and Linda; the implications of the synergy between the two systems are examined, and suggestions for future work are proposed.We begin with an examination of the Eiffel execution model, with particular reference to its emphasis on the correct construction of software systems. We briefly describe the Linda language, and compare it to other parallelism models. The unified Eiffel Linda language is then presented, with discussion of the semantic issues which were considered in the course of its evolution, and details of the interesting features of our particular implementation. Comparisons to past work in Linda and in object-oriented concurrency are offered. In conclusion, we reflect on the significance of Eiffel Linda, and consider its relevance to future work in object-based concurrency.
Modelling context dependency in acoustic-phonetic and lexical representations
Authors: Michael Phillips, James Glass, Victor Zue
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

In 1989, our group first reported on the development of SUMMIT, a segment-based speaker-independent continuous-speech recognition system [13]. The initial version of SUMMIT made use of fairly simple context-independent models for the lexical labels. Recently, we have begun to incorporate more complex models of lexical labels that take into account a variety of contextual factors. These changes, along with an improved corrective training procedure for adapting pronunciation are weights and a larger set of training data, have resulted in the reduction of error rate by almost a factor of two on the Resource Management task.
A simple taxonomy for distributed mutual exclusion algorithms
Authors: Michel Raynal
Venue: ACM SIGOPS Operating Systems Review (1991)

This short paper examines the two basic principles from which distributed mutual exclusion algorithms are designed : permission-based and token-based principles. This presentation is done in a pedagogical way and is illustrated by references to existing algorithms.
Making radiosity usable: automatic preprocessing and meshing techniques for the generation of accurate radiosity solutions
Authors: Daniel R. Baum, Stephen Mann, Kevin P. Smith, James M. Winget
Venue: Proceedings of the 18th annual conference on Computer graphics and interactive techniques (1991)

Generating accurate radiosity solutions of real world environments is user-intensive and requires significant knowledge of the method. As a result, few end-users such as architects and designers use it. The output of most commercial modeling packages must be substantially "cleaned up" to satisfy the geometrical and topological criteria imposed by radiosity solution algorithms. Furthermore, the mesh used as the basis of the radiosity computation must meet several additional requirements for the solution to be accurate.A set of geometrical and topological requirements is formalized that when satisfied yields an accurate radiosity solution. A series of algorithms is introduced that automatically processes raw model databases to meet these requirements. Thus, the end-user can concentrate on the design rather than on the details of the radiosity solution process. These algorithms are generally independent of the radiosity solution technique used, and thus apply to all mesh based radiosity methods.
A Window Protocol for Transmission of Time-Constrained Messages
Authors: Wei Zhao, John A. Stankovic, Krithi Ramamritham
Venue: IEEE Transactions on Computers (1990)

The authors propose and study a window protocol suitable for transmitting time-constrained messages in a multiaccess network. The protocol differs from traditional window protocols in that it explicitly takes time constraints into account. The window is formed on the basis of the latest time to send a message (LS). A major advantage of the window protocol is that a newly arriving message is immediately considered for transmission if its LS is less than that of all pending messages in the system. As a result, the protocol closely approximates the optimal minimum-laxity-first policy. A performance evaluation through simulation shows that the protocol performs well in a wide range of environments, including under overloaded conditions.
Distributed Representations, Simple Recurrent Networks, And Grammatical Structure
Authors: Jeffrey L. Elman
Venue: Machine Learning (1991)

In this paper three problems for a connectionist account of language are considered:1. What is the nature of linguistic representations?2. How can complex structural relationships such as constituent structure be represented?3. How can the apparently open-ended nature of language be accommodated by a fixed-resource system?Using a prediction task, a simple recurrent network (SRN) is trained on multiclausal sentences which contain multiply-embedded relative clauses. Principal component analysis of the hidden unit activation patterns reveals that the network solves the task by developing complex distributed representations which encode the relevant grammatical relations and hierarchical constituent structure. Differences between the SRN state representations and the more traditional pushdown store are discussed in the final section.
Boundary Finding with Parametrically Deformable Models
Authors: Lawrence H. Staib, James S. Duncan
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

Segmentation using boundary finding is enhanced both by considering the boundary as a whole and by using model-based global shape information. The authors apply flexible constraints, in the form of a probabilistic deformable model, to the problem of segmenting natural 2-D objects whose diversity and irregularity of shape make them poorly represented in terms of fixed features or form. The parametric model is based on the elliptic Fourier decomposition of the boundary. Probability distributions on the parameters of the representation bias the model to a particular overall shape while allowing for deformations. Boundary finding is formulated as an optimization problem using a maximum a posteriori objective function. Results of the method applied to real and synthetic images are presented, including an evaluation of the dependence of the method on prior information and image quality.
An adaptive tenuring policy for generation scavengers
Authors: David Ungar, Frank Jackson
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1992)

One of the more promising automatic storage reclamation techniques, generation scavenging, suffers poor performance if many objects live for a fairly long time and then die. We have investigated the severity of this problem by simulating a two-generation scavenger using traces taken from actual 4-h sessions. There was a wide variation in the sample runs, with garbage-collection overhead ranging from insignificant, during three of the runs, to severe, during a single run. All runs demonstrated that performance could be improved with two techniques: segregating large bitmaps and strings, and adapting the scavenger's tenuring policy according to demographic feedback. We therefore incorporated these ideas into a commercial Smalltalk implementation. These two improvements deserve consideration for any storage reclamation strategy that utilizes a generation scavenger.
Efficient Tridiagonal Solvers on Multicomputers
Authors: Xian-He Sun, Hong Zhang, Lionel M. Ni
Venue: IEEE Transactions on Computers (1992)

Three parallel algorithms, namely, the parallel partition LU (PPT) algorithm, the parallel partition hybrid (PPH) algorithm, and the parallel diagonal dominant (PDD) algorithm, are proposed for solving tridiagonal linear systems on multicomputers. These algorithms are based on the divide-and-conquer parallel computation model. The PPT and PPH algorithms support both pivoting and nonpivoting. The PPT algorithm is good when the number of processors is small; otherwise, the PPH algorithm is better. When the system is diagonal dominant, the PDD algorithm is highly parallel and provides an approximate solution which equals the exact solution within machine accuracy. Computation and communication complexities of the three algorithms are presented. All three methods have been implemented on a 64-node nCUBE-1 multicomputer. The analytic results closely match the results measured from the nCUBE-1 machine.