ppxscal/embedding_network huggingface dataset:
Optimization of a subclass of conjunctive queries (extended abstract)
Authors: Pratul Dublish, Joachim Biskup
Venue: Proceedings of the third international conference on database theory on Database theory (1990)

The optimization problem for a subclass of conjunctive queries which is formed by the union of the class of fan-out free queries and a subclass of typed fan-out queries is investigated. The typed fan-out queries in this class are obtained from simple tableaux by allowing at most one attribute to violate the simple-tableau property. The optimization problem for several restricted subsets of typed fan-out queries is already known to be NP-hard. It is shown that the queries under consideration possess several useful properties which are then used to obtain an O(n2) optimization algorithm based on the implication graph technique. The optimization of typed fan-out queries, obtained from simple tableaux by allowing at most two attributes to violate the simple tableau property, is shown to be NP-hard.
Applications of best approximation
Authors: Charles Dunham
Venue: ACM SIGNUM Newsletter (1991)

We attempt to classify the known applications of the theory of best approximation so that attention can be focused on useful problems.
Wimps and nerds: an extended view of the user interface
Authors: Mark H. Chignell, John A. Waterworth
Venue: ACM SIGCHI Bulletin (1991)

Since the introduction of the Xerox Star computer and its more popular successor, the Apple Macintosh, the so-called WIMP interface has become predominant in software interfaces. In this paper we discuss the fact that the WIMP interface handles the physical, but not the cognitive interface to software. We propose to supplement the WIMP model of the physical interface with the NERD model of the cognitive interface. Like the WIMP model, the NERD model is designed to enhance interface consistency and to increase the power of the user while reducing cognitive load associated with the task.
Generalized implicit functions for computer graphics
Authors: Stan Sclaroff, Alex Pentland
Venue: ACM SIGGRAPH Computer Graphics (1991)

We describe a method of generalizing implicit functions by use of modal deformations and displacement maps. Modal deformations, also known as free vibration modes, are used to describe the overall shape of a solid, while displacement maps provide local and fine surface detail by offsetting the surface of the solid along its surface normals. The advantage of this approach to geometric description is that collision detection and dynamic simulation become simple and inexpensive even for complex shapes. In addition, we outline an efficient method for fitting such models to three dimensional point data.
A taxonomy for programming style
Authors: Paul W. Oman, Curtis R. Cook
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

Programming style guidelines, style analyzers, and code formatters have been developed without a solid empirical or theoretical basis. In this paper we provide: (1) a justification for developing a programming style taxonomy, (2) an operational style taxonomy, (3) example applications of the taxonomy illustrating the diverse and sometimes contradictory nature of programming style guidelines, and (4) a discussion on how the taxonomy can be used to further teaching and research in programming style. The taxonomy provides a context for understanding and identifying specific style factors and empirical studies necessary to determine the effects of style on program comprehension. The results of this paper have a direct impact on programming instruction, programming standards, automated style analyzers, and code formatting tools like pretty-printers and syntax directed editors.
Proving memory management invariants for a language based on linear logic
Authors: Jawahar Chirimar, Carl A. Gunter, Jon G. Riecke
Venue: Proceedings of the 1992 ACM conference on LISP and functional programming (1992)

We develop tools for the rigorous formulation and proof of properties of runtime management for a sample programming language based on a linear type system. Two semantics are diescribed, one at a level of observable results of computations and one describing linear connectives in terms of memory-management primitives. The two semantics are proven equivalent and the memory-management model is proven to satisfy fundamental correctness criteria for reference counts.
Funding for small US businesses and from DARPA and NASA
Authors: Marianne Winslett
Venue: ACM SIGMOD Record (1991)

This column is the first of a regular series describing database funding programs in the United States and abroad. I plan to include profiles of major funding agencies and programs, major efforts underway, new calls for proposals, and the outcomes of funding initiatives. I welcome submissions of relevant material; they can be sent to winslett@cs.uiuc.edu. In this issue, I describe funding in the database area for innovative research in small US businesses, and new requests for proposals from DARPA and from NASA.
A reverse engineering environment based on spatial and visual software interconnection models
Authors: H. A. Müller, S. R. Tilley, M. A. Orgun, B. D. Corrie, N. H. Madhavji
Venue: ACM SIGSOFT Software Engineering Notes (1992)

Reverse engineering is the process of extracting system abstractions and design information out of existing software systems. This information can then be used for subsequent development, maintenance, re-engineering, or reuse purposes. This process involves the identification of software artifacts in a particular subject system, and the aggregation of these artifacts to form more abstract system representations. This paper describes a reverse engineering environment which uses the spatial and visual information inherent in graphical representations of software systems to form the basis of a software interconnection model. This information is displayed and manipulated by the reverse engineer using an interactive graph editor to build subsystem structures out of software building blocks. The spatial component constitutes information about how a software structure looks. The coexistence of these two representations is critical to the comprehensive appreciation of the generated data, and greatly benefits subsequent analysis, processing, and decision-making.
The Boston University Manufacturing Expert System (BUMES): an APL-based CASE application
Authors: T. Shojaie, L. Zeidner, S. Sadri, Y. Hazony
Venue: Proceedings of the international conference on APL '91 (1991)

Manufacturing engineering involves the processes and equipment required to design, analyze, fabricate, and test products. The transition from an engineer's first sketch to a finished, machined part is traditionally a long, expensive, difficult path. This path includes a variety of separate software solutions to individual subproblems. Together, these separate solutions raise many confusing issues of capability, compatibility, and design integrity. This paper presents the design and implementation of a fully integrated solution to this problem. This system enables a designer to sketch a part graphically, and immediately have it machined. Because this rapid-prototyping system was designed as an integrated solution, it allows the process rules to be available up-front in the part design stage, so that unmanufacturable design features are identified immediately, as the designer attempts to add them to the part. This rapid-prototyping capability also addresses the need to modify the part by changing its dimensions or its features. Design changes and subsequent machining are rapid because of the use of relational geometry, which remembers the geometric relationships between the part's geometric elements, so that if some are changed, all can be adjusted automatically. The prototype Boston University Manufacturing Expert System (BUMES) was designed and implemented using the Expert System Generator (ESG) CASE tool, in APL2.
Optimization of object-oriented recursive queries using cost-controlled strategies
Authors: Rosana S. G. Lanzelotte, Patrick Valduriez, Mohamed Zaït
Venue: ACM SIGMOD Record (1992)

Object-oriented data models are being extended with recursion to gain expressive power. This complicates the optimization problem which has to deal with recursive queries on complex objects. Because unary operations invoking methods or path expressions on objects may be costly to execute, traditional heuristics for optimizing recursive queries are no longer valid. In this paper we propose a cost-based optimization method which handles object-oriented recursive queries. In particular, it is able to delay the decision of pushing selective operations through recursion until the effect of such a transformation can be measured by a cost model. The approach integrates rewriting and increases the optimization opportunities for recursive queries on objects while allowing for efficient optimization.
Architectural support for register allocation in the presence of aliasing
Authors: Ben Heggy, Mary Lou Soffa
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

High performance computer architectures use registers to provide high speed access to data operands, to provide short names for operands, and to reduce memory traffic for accesses to these operands. The possibility of aliasing in a program segment reduces the quality of code that a compiler can produce by necessitating that memory and register copies of variables that have been allocated to registers be kept consistent. A hardware support mechanism is presented that permits all classes of data objects, including dynamically allocated objects and array elements, to be held in registers without consideration of possible aliases and without requiring that the generated code maintain consistency between register and memory copies of variables. Use of this approach permits programs to benefit from the speed advantages and reduced memory traffic associated with register storage, obviates the need to collect aliasing information for use in register allocation, and reduces instruction traffic by eliminating code used solely to maintain register-memory consistency. The support hardware can be implemented using known hardware technology and without increasing the cycle time of the processor.
Deterministic priority inversion in Ada selective waits
Authors: Leslie Lander, Sandeep Mitra, Thomas Piatkowski
Venue: ACM SIGAda Ada Letters (1990)

Priority inversion is any situation where low priority tasks are served before higher priority tasks. It is recognized as a serious problem for real-time systems. In the course of building a performance model for multi-tasking Ada software, we have noticed that a fair algorithmic selection procedure may be likely to cause priority inversion in selective waits. This effect is in addition to the well-known priority inversion due to the FIFO nature of entry queues. As an illustration, we present a semi-formal partial model of the selective wait algorithm of the Alsys1 ' 286 DOS Ada Compiler v4.2, running under PC-DOS Version 3.30 on an IBM PC/AT2 The model was deduced from a series of experiments designed to illuminate the scheduling features of the system. These results may provide useful insight for users of this and other Ada compilers since priority inversion may occur in the way we describe in many systems. We also indicate one standard technique to avoid priority inversion at selective waits.
Towards a semantic view of an extended entity-relationship model
Authors: Martin Gogolla, Uwe Hohenstein
Venue: ACM Transactions on Database Systems (TODS) (1991)

Nearly all query languages discussed recently for the Entity-Relationship (ER) model do not possess a formal semantics. Languages are often defined by means of examples only. The reason for this phenomenon is the essential gap between features of query languages and theoretical foundations like algebras and calculi. Known languages offer arithmetic capabilities and allow for aggregates, but algebras and calculi defined for ER models do not. This paper introduces an extended ER model concentrating nearly all concepts of known so-called semantic data models in a few syntactical constructs. Moreover, we provide our extended ER model with a formal mathematical semantics. On this basis a well-founded calculus is developed taking into account data operations on arbitrary user-defined data types and aggregate functions. We pay special attention to arithmetic operations, as well as multivalued terms allowing nested queries, in a uniform and consistent manner. We prove our calculus only allows the formulation of safe terms and queries yielding a finite result, and to be (at least) as expressive as the relational calculi.
Management information systems curricula in the United States and the Republic of China: a comparative study
Authors: Betty W. Hwang, Andrew B. Whinston, Wilhelmina Savenye
Venue: Proceedings of the twenty-third SIGCSE technical symposium on Computer science education (1992)

The purpose of this study was to investigate and compare the Management Information Systems (MIS) curricula in higher education in the United States (U.S.) and the Republic of China (R.O.C.). Several factors that affect the MIS curricula and its development in these two countries were closely examined. Similarities and differences were identified and compared; strengths and weaknesses were analyzed and described. In particular, this study focused on the undergraduate MIS programs in both countries. Comparisons of the MIS programs were made concerning: MIS program history, MIS program setting, admission requirements and standards, graduation requirements and standards, computer hardware and software facilities, curriculum model adopted, required courses, instructional methods, faculty profiles, student profiles, and relationships with the industry. Based on the findings, some recommendations for improving the Chinese MIS curricula were offered.
When TVs are computers are TVs (panel)
Authors: S. Joy Mountford, Peter Mitchell, Pat O'Hara, Joe Sparks, Max Whitby
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

This panel brings together experts from TV production with those in the computer multimedia business. They will discuss what is likely to happen when the two media coexist. An exciting opportunity exists in merging the strengths of both media together synergistically to create pervasive and powerful Interactive Television.
Orthogonal Defect Classification-A Concept for In-Process Measurements
Authors: Ram Chillarege, Inderpal S. Bhandari, Jarir K. Chaar, Michael J. Halliday, Diane S. Moebus, Bonnie K. Ray, Man-Yuen Wong
Venue: IEEE Transactions on Software Engineering (1992)

Orthogonal defect classification (ODC), a concept that enables in-process feedback to software developers by extracting signatures on the development process from defects, is described. The ideas are evolved from an earlier finding that demonstrates the use of semantic information from defects to extract cause-effect relationships in the development process. This finding is leveraged to develop a systematic framework for building measurement and analysis methods. The authors define ODC and discuss the necessary and sufficient conditions required to provide feedback to a developer; illustrate the use of the defect type distribution to measure the progress of a product through a process; illustrate the use of the defect trigger distribution to evaluate the effectiveness and eventually the completeness of verification processes such as inspection or testing; provides sample results from pilot projects using ODC; and open the doors to a wide variety of analysis techniques for providing effective and fast feedback based on the concepts of ODC.
On the degree of polynomials that approximate symmetric Boolean functions (preliminary version)
Authors: Ramamohan Paturi
Venue: Proceedings of the twenty-fourth annual ACM symposium on Theory of computing (1992)

In this paper, we provide matching (up to a constant factor) upper and lower bounds on the degree of polynomials that represent symmetric boolean functions with an error 1/3. Let &Ggr;(f)=min{|2k&ndash;n+1|:fk &ne; fk+ 1 and 0 &le; k &le; n &ndash; 1} where fi is the value of f on inputs with exactly i 1's. We prove that the minimum degree over all the approximating polynomials of f is &THgr;((n(n-&Ggr;(f))).5). We apply the techniques and tools from approximation theory to derive this result.
Database systems: achievements and opportunities
Authors: Avi Silberschatz, Michael Stonebraker, Jeffrey D. Ullman
Venue: ACM SIGMOD Record (1990)

The history of database system research in the U.S. is one of exceptional productivity and startling economic impact. Barely twenty years old as a basic science research field, database research conducted with Federal support in the nation's universities and in its industrial research laboratories has fueled an information services industry estimated at $10 billion per year in the U.S. alone. This industry has grown at an average rate of 20 percent per year since 1965 and is continuing to expand at this rate. Achievements in database research underpin fundamental advances in communications systems, transportation and logistics, financial management, knowledge-based systems, accessibility to scientific literature, and a host of other civilian and defense applications. They also serve as the foundation for considerable progress in basic science in various fields ranging from computing to biology.
Recognition of noisy speech: using minimum-mean log-spectral distance estimation
Authors: A. Erell, M. Weintraub
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

A model-based spectral estimation algorithm is derived that improves the robustness of speech recognition systems to additive noise. The algorithm is tailored for filter-bank-based systems, where the estimation should seek to minimize the distortion as measured by the recognizer's distance metric. This estimation criterion is approximated by minimizing the Euclidean distance between spectral log-energy vectors, which is equivalent to minimizing the nonweighted, nontruncated cepstral distance. Correlations between frequency channels are incorporated in the estimation by modeling the spectral distribution of speech as a mixture of components, each representing a different speech class, and assuming that spectral energies at different frequency channels are uncorrelated within each class. The algorithm was tested with SRI's continuous-speech, speaker-independent, hidden Markov model recognition system using the large-vocabulary NIST "Resource Management Task." When trained on a clean-speech database and tested with additive white Gaussian noise, the new algorithm has an error rate half of that with MMSE estimation of log spectral energies at individual frequency channels, and it achieves a level similar to that with the ideal condition of training and testing at constant SNR. The algorithm is also very efficient with additive environmental noise, recorded with a desktop microphone.
Mathematical problems arising in qualitative simulation of a differential equation
Authors: Olivier Dordan
Venue: Artificial Intelligence (1992)

Kuiper's QSIM algorithm is an expert system which studies the qualitative evolution of a differential inclusion. This paper addresses several issues raised by QSIM-type algorithms attached to landmark values, by using the concept of QQqualitative cells/Q/Q. Only the systems which share the same behavior on the boundary between two cells can be analyzed qualitatively. The principal purpose of this paper is to associate with a differential equation its QQqualitative projection/Q/Q which assigns to each qualitative cell its QQsuccessors/Q/Q, to show how this algorithm can be implemented, and to illustrate the results with QQreplicator systems/Q/Q: a class of differential equation used in biochemistry and biology. &mdash;Author's Abstract
Comparative performance evaluation of cache-coherent NUMA and COMA architectures
Authors: Per Stenström, Truman Joe, Anoop Gupta
Venue: Proceedings of the 19th annual international symposium on Computer architecture (1992)

Two interesting variations of large-scale shared-memory machines that have recently emerged are cache-coherent non-uniform-memory-access machines (CC-NUMA) and cache-only memory architectures (COMA). They both have distributed main memory and use directory-based cache coherence. Unlike CC-NUMA, however, COMA machines automatically migrate and replicate data at the main-memory level in cache-line sized chunks. This paper compares the performance of these two classes of machines. We first present a qualitative model that shows that the relative performance is primarily determined by two factors: the relative magnitude of capacity misses versus coherence misses, and the granularity of data partitions in the application. We then present quantitative results using simulation studies for eight parallel applications (including all six applications from the SPLASH benchmark suite). We show that COMA's potential for performance improvement is limited to applications where data accesses by different processors are finely interleaved in memory space and, in addition, where capacity misses dominate over coherence misses. In other situations, for example where coherence misses dominate, COMA can actually perform worse than CC-NUMA due to increased miss latencies caused by its hierarchical directories. Finally, we propose a new architectural alternative, called COMA-F, that combines the advantages of both CC-NUMA and COMA.
What price reusability?: a case study
Authors: John Favaro
Venue: ACM SIGAda Ada Letters (1991)

This paper reports on experiences gained from a year-long industrial development project that made use of a popular repository of reusable components. The results of applying an existing framework for quantifying the economics of reuse are presented.
Formalization of Protocol Engineering Concepts
Authors: Paul W. King
Venue: IEEE Transactions on Computers (1991)

A vast variety of design principles and formal description techniques (FDTs) have been advocated to help contend with the ever-increasing complexity of communication system development. However, the relationship between these principles and FDTs is unclear. The author formalizes a number of concepts relevant to the design principles and FDTs used to develop communication protocols. The concepts are divided into behavioral and structural concepts. Four behavioral models and a number of associated properties are defined as a basis for comparing and integrating FDTs. Two structural models, which extend the behavioral models, are then presented, and several structural concepts are defined in terms of these models. The models and properties defined within this framework are used to briefly characterize a number of FDTs. The representative FDTs considered here are Petri nets, LOTOS, a relational notation, the Z notation, and Object-Z.
Elements of a computational model of cooperative response generation
Authors: Brant A. Cheikes, Bonnie L. Webber
Venue: Proceedings of the workshop on Speech and Natural Language (1989)

If natural language question-answering (NLQA) systems are to be truly effective and useful, they must respond to queries <i>cooperatively</i>, recognizing and accommodating in their replies a questioner's goals, plans, and needs. This paper concerns the design of <i>cooperative response generation</i> (CRG) systems, NLQA systems that are able to produce integrated cooperative responses. We propose two characteristics of a computational model of cooperative response generation. First, we argue that CRG systems should be able to explicitly reason about and choose among the different response options available to them in a given situation. Second, we suggest that some choices of response content motivate others---that through a process called <i>reflection</i>, respondents detect the need to explain, justify, clarify or otherwise augment information they have already decided to convey.