ppxscal/embedding_network huggingface dataset:
Bounds on the propagation of selection into logic programs
Authors: C. Beeri, P. Kanellakis, F. Bancilhon, R. Ramakrishnan
Venue: Proceedings of the sixth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1987)

We consider the problem of propagating selections (i.e., bindings of variables) into logic programs. In particular, we study the class of binary chain programs and define selection propagation as the task of finding an equivalent program containing only unary derived predicates. We associate a context free grammar L(H) with every binary chain program H. We show that, given H propagating a selection involving some constant is possible iff L(H) is regular, and therefore undecidable. We also show that propagating a selection of the form p(X,X) is possible iff L(H) is finite, and therefore decidable. We demonstrate the connection of these two cases, respectively, with the weak monadic second order theory of one successor and with monadic generalized spectra. We further clarify the analogy between chain programs and languages from the point of view of program equivalence and selection propagation heuristics.
LAN requirements for air traffic control
Authors: K. J. Thurber, N. E. Schmidt, E. S. Nolley
Venue: Proceedings of the 1987 Fall Joint Computer Conference on Exploring technology: today and tomorrow (1987)

This paper summarizes the architectural requirements of computer communications for Air Traffic Control (ATC), using the Federal Aviation Administration's (FAA) future Advanced Automation System (AAS). The requirements include distributed processing, high availability, and interfacing to additional systems provided by other contractors. The system must have high performance as well as extensive routing capabilities. Architectural issues include modularity, intelligent workstations, global access and the management of information. Air traffic control requires very high system availability. This demands the use of redundancy, comprehensive fault detection and recovery, extensive testing, and network management.
Computing convolutions by reciprocal search
Authors: L Guibas, R Seidel
Venue: Proceedings of the second annual symposium on Computational geometry (1986)

In this paper we show how certain geometric convolution operations can be computed efficiently. Here &ldquo;efficiently&rdquo; means that our algorithms have running time proportional to the input size plus the output size. Our convolution algorithms rely on new optimal solutions for certain reciprocal search problems, such as finding intersections between &ldquo;blue&rdquo; and &ldquo;green&rdquo; intervals, and overlaying convex planar subdivisions.
Performance evaluation of reduced bandwidth multistage interconnection networks
Authors: D. T. Harper,  III, J. R. Jump
Venue: Proceedings of the 14th annual international symposium on Computer architecture (1987)

This paper presents and evaluates a class of buffered interconnection networks which provide performance and cost levels intermediate to a bus and a delta network. These networks, referred to as hybrid networks, are formed by beginning with a delta network and substituting buses for the final stages of the network. The choice of the number of stages replaced determines the bandwidth of the network. The reduction of network bandwidth is accompanied by a corresponding reduction in network cost. Hybrid networks provide the system architect with a cost-effective solution to design problems in which the required interconnection bandwidth is greater than that of a bus but less than that of a full delta network. The performance of hybrid networks is investigated by developing a numerical model and by using simulation. Two features of the model, buffers of arbitrary length at network switches and resource service times greater than interstage transfer delays, have not been included in previous analytical models of delta networks. Results show that in some cases, the expense of a multistage network is not required in order to maintain the maximum level of system performance.
Processor Scheduling for Linearly Connected Parallel Processors
Authors: Charles E. McDowell, William F. Appelbe
Venue: IEEE Transactions on Computers (1986)

A low-level parallel processor (LLPP) is one in which two or more machine-level operations are executed in parallel. This paper analyzes the use of linearly connected LLPP's for parallel evaluation of program fragments. A graph-theoretic model is presented which describes the communication constraints of linearly connected parallel processors. A tight, necessary condition for finding assignments of program fragments to linearly connected LLPP's that require no communication delays is presented. Also, several weak sufficient conditions have been found and efficient heuristics for determining optimal assignments have been developed.
Using a planner to support office work
Authors: W. B. Croft, L. S. Lefkowitz
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

Supporting a wide range of activities in offices has been a major objective for designers of office systems. The complex nature of office work and the fact that there are no simple limits on the amount of domain knowledge required to do this work have made the achievement of this objective very difficult. Planning and representation techniques from artificial intelligence appear to have some advantages for this task in terms of flexibility and adaptability. In this paper we describe the POLYMER planning system and representation language. In particular, we point out the system components that are required to make planning useful in real environments. The operation of the system is illustrated using an example activity.
Design of a Functionally Distributed, Multiprocessor Database Machine Using Data Flow Analysis
Authors: T. Baba, S. Bing Yao, A. R. Hevner
Venue: IEEE Transactions on Computers (1987)

We propose a design methodology based on data flow analysis for a functionally distributed, multiprocessor database machine. We define a cost model of database processing with the objective cost being response time of a set of query strategies. Heuristic optimization techniques are proposed using the operations of grouping, decomposition, and replication. We apply the new optimization techniques in several realistic multiprocessor environments. The resulting configurations of multiprocessors demonstrate significant performance improvements over more traditional designs.
Software development environments
Authors: P B Henderson
Venue: ACM SIGSOFT Software Engineering Notes (1987)

I just returned from California after attending the Second SIGSOFT/SIGPLAN ACM Symposium on Practical Software Development Environments held December 9-12 in Palo Alto. I feel the meeting was very successful and served its main purposes - to access the current state of the art in the environments area and to help define the important issues which must still be addressed. An objective evaluation of the symposium by Karl Reed is included in this subsection and I will present my overall views shortly.
Computing the link center of a simple polygon
Authors: W. Lenhart, R. Pollack, J. Sack, R. Seidel, M. Sharir
Venue: Proceedings of the third annual symposium on Computational geometry (1987)

The link center of a simple polygon P is the set of points x inside P at which the maximal link-distance from x to any other point in P is minimized, where the link distance between two points x, y inside P is defined as the smallest number of straight edges in a polygonal path inside P connecting x to y. We prove several geometric properties of the link center and present an algorithm that calculates this set in time &Ogr; (n2), where n is the number of sides of P. We also give an &Ogr;(n log n) algorithm for finding a point x in an approximate link center, namely the maximal link distance from x to any point in P is at most one more than the value attained from the link center.
Epidemic algorithms for replicated database maintenance
Authors: Alan Demers, Dan Greene, Carl Houser, Wes Irish, John Larson, Scott Shenker, Howard Sturgis, Dan Swinehart, Doug Terry
Venue: ACM SIGOPS Operating Systems Review (1988)

When a database is replicated at many sites, maintaining mutual consistency among the sites in the face of updates is a significant problem. This paper describes several randomized algorithms for distributing updates and driving the replicas toward consistency. The algorithms are very simple and require few guarantees from the underlying communication system, yet they ensure that the effect of every update is eventually reflected in all replicas. The cost and performance of the algorithms are tuned by choosing appropriate distributions in the randomization step. The algorithms are closely analogous to epidemics, and the epidemiology literature aids in understanding their behavior. One of the algorithms has been implemented in the Clearinghouse servers of the Xerox Corporate Internet. solving long-standing problems of high traffic and database inconsistency.
Multiple Stuck-Fault Detection and Location in Multivalued Linear Circuits
Authors: Chuen-Liang Chen, Min-Wen Du
Venue: IEEE Transactions on Computers (1986)

In this correspondence, we present procedures for constructing universal fault detection test sets as well as fault location test sets for multivalued linear circuits, under a multiple stuck-fault model. The bin packing problem is involved in the procedures. The sizes of the fault detection test set and the fault location test set constructed for an n- variable v-valued linear tree circuit are 1 + ?n/(v - 1)? and 1 + ?n/ ?log2 v? ?, respectively. It has been proved that the sizes listed above are optimal for some cases.
A new imaging method and its application in gynecological treatment planning
Authors: K. H. Englmeier, S. J. Pöppi
Venue: ACM SIGBIO Newsletter (1987)

Intracavitary afterloading therapy -- a customary system to treat malignant tumours in gynaecology -- has received an appropriate basis by development of intrauterine ultrasound, because on the one hand sonographic probe and afterloading probe produce the same geometric circumstances and on the other intrauterine ultrasound has proved to be a method for showing normal myometrium and detecting its pathologic modified regions, especially for localisation and infiltration depth of malignant processes. After computer assisted segmentation and reconstruction of organ slices in three dimensional domain various dose distributions are calculated in case of carcinoma of the body of the uterus. They are produced by various probes and times, during which the radioactive source stops. Using a system of decision rules, a therapy plan is selected, which is an optimum adaptation to the individual geometric circumstances.
Performance analysis of a satellite communications backchannel architecture
Authors: D Baum
Venue: ACM SIGCOMM Computer Communication Review (1986)

The definition of a backchannel architecture for open systems interconnection over satellite links has been the subject of the SENS-project1 The new proposal is based on existent international standards and uses the options of the ISO-class 4 transport layer protocol in order to enclose in level 4 data link control functions for unidirectional satellite links following the rules of the IBM-checkpoint protocol. This paper provides performance values of the SENS architecture in comparison with those of common satellite communication systems. With means of elementary probability theoretical methods an approximate analysis of the IBM-checkpoint protocol is accomplished. The results show that for large amounts of data the new architecture proves to be best suited for cost efficient use of public satellite data links.
A Special-Function Unit for Sorting and Sort-Based Database Operations
Authors: L Raschid, T Fei, H Lam, S Y W Su
Venue: IEEE Transactions on Computers (1986)

Achieving efficiency in database management functions is a fundamental problem underlying many computer applications. Efficiency is difficult to achieve using the traditional general-purpose von Neumann processors. Recent advances in microelectronic technologies have prompted many new research activities in the design, implementation, and application of database machines which are tailored for processing database management functions. To build an efficient system, the software algorithms designed for this type of system need to be tailored to take advantage of the hardware characteristics of these machines. Furthermore, special hardware units should be used, if they are cost- effective, to execute or to assist the execution of these software algorithms.
Best &ldquo;ordering&rdquo; for floating-point addition
Authors: T. G. Robertazzi, S. C. Schwartz
Venue: ACM Transactions on Mathematical Software (TOMS) (1988)

This correspondence examines the influence of the summation order on the numerical accuracy of the resulting sum when the addition is performed using floating-point, finite-precision arithmetic. A simple statistical model is used to find the relative performance of various addition procedures. It is shown that phrasing the question in terms of finding a best ordering is overly restrictive since the most natural and accurate procedures for performing the addition utilize the storage of intermediate sums as well as performing orderings.
Object flavor evolution in an object-oriented database system
Authors: Qing Li, Dennis McLeod
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

The ability to gracefully accommodate dynamic evolution is essential in data-intensive office information systems. Among the wide spectrum of kinds of conceptual database modification, there is an important subkind which involves changes to the fundamental semantics of objects, vis-a-vis their nature as symbolic, abstract, type (set), relationship (mapping), or behavioral (procedure). This kind of change is termed &ldquo;object flavor evolution&rdquo;. For example, a real-world concept modelled in a database as a symbolic object (e.g., a string denoting the name of a person) may later evolve to or be alternatively viewed as an abstract object (e.g., a person entity). This paper examines object flavor evolution in the context of a simple, extensible object-oriented database model; this model is the kernel of an experimental prototype system termed PKM (for &ldquo;personal knowledge manager&rdquo;) currently under development. The PKM object-oriented modelling constructs and operations are presented, along with a description and analysis of specific kinds of object flavor evolution.
Industrial-strength software engineering for large organizations
Authors: J. H. Manley
Venue: Proceedings of the 1987 Fall Joint Computer Conference on Exploring technology: today and tomorrow (1987)

In trying to solve our large organization software problems (see other papers in this conference), we may be doing the wrong things better! Large automated systems development and lifetime support requires &ldquo; industrial-strength&rdquo; management and engineering. This must include software engineers possessing broad user-domain-specific knowledge concerning the operating requirements of the target systems being constructed. In other words, a fundamental change is necessary in the &ldquo; mind set&rdquo; of many software professionals, be they engineers or managers. This paper advises us to step back and take a close look at what people really do in other large organizations in general, and in software-intensive organizations in particular. Many will be surprised at what they see, and perhaps begin to solve problems differently than they have in the past.
Establishing a faculty computing resource library
Authors: J. E. Diem, Allison Hartman, Kirsty D. Nunez
Venue: Proceedings of the 15th annual ACM SIGUCCS conference on User Services (1987)

The Tulane Computing Services (TCS) Faculty Computing Resource Library contains computing resources which can be borrowed on a short-term basis by Tulane University faculty. Library holdings include microcomputer software and documentation, mainframe computer documentation, computing books and periodicals, and computing hardware (microcomputers, modems and cables). The Library was established to provide faculty with access to a central repository of computing resources for evaluation and short-term, occasional use. Holdings are listed in a regularly updated catalog. One of the computing services staff consultants serves as Library Coordinator with assistance from student employees and the TCS Consultants Bureau secretary. All faculty are eligible to become members of the Faculty Computing Resource Library. To become a member, the individual must sign a User's Agreement acknowledging copyright and licensing laws and accepting responsibility for lost or damaged software, documentation and equipment. Holdings for the Library are purchased from vendors as permitted by the Computing Services budget. Many items have been donated to the Library, both by vendors and by the dean's offices of the University's schools and colleges. The University Library provides advice on aspects of library management and acquisition of holdings.
The complexity of problems on probabilistic, nondeterministic, and alternating decision trees
Authors: Udi Manber, Martin Tompa
Venue: Journal of the ACM (JACM) (1985)

This work generalizes decision trees in order to study lower bounds on the running times of algorithms that allow probabilistic, nondeterministic, or alternating control. It is shown that decision trees that are allowed internal randomization (at the expense of introducing a small probability of error) run no faster asymptotically than ordinary decision trees for a collection of natural problems. Two geometric techniques from the literature for proving lower bounds on the time required by ordinary decision trees are shown to be special cases of one unified technique that, in fact, applies to nondeterministic decision trees as well. Finally, it is shown that any lower bound on alternating decision tree time also applies to alternating Turing machine time.
Symbolic packages in the development of numerical algorithms
Authors: John de Pillis
Venue: ACM SIGNUM Newsletter (1987)

Our research has the objective of finding quicker, more efficient numerical methods (computer algorithms) for solving large, sparse linear systems. Yet, in the development and discovery of new methods, we have been relying on auxiliary software packages.
Collaborative modeling and negotiation
Authors: Dhanesh Samarasan
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

New problems in negotiation call for a new framework of solutions. Negotiation management, one such framework, has at its heart the application of computer models and related technology to a collaborative effort at dispute resolution. In this paradigm, negotiation is treated as a communicative and knowledge-intensive group problem-solving process. Easily accessible techniques are being developed for modeling both the process and substance of negotiation. In addition, tools are being designed for negotiators to use in risk and decision analysis, optimization, and precedent analysis. This paper outlines a synthesis of these elements in an integrated computer environment for negotiation management.
Finding the minimum visible vertex distance between two non-intersecting simple polygons
Authors: C Wang, E P F Chan
Venue: Proceedings of the second annual symposium on Computational geometry (1986)

In this paper, we present an &Ogr;(n log n) algorithm for finding the minimum Euclidean visible vertex distance between two nonintersecting simple polygons, where n is the number of vertices in a polygon. The algorithm is based on applying a divide and conquer method to two preprocessed facing boundaries of the polygons. We also derive an &Ogr;(n log n) algorithm for finding a minimum sequence of separating line segments between two nonintersecting polygons.
ESP: a new standard cell placement package using simulated evolution
Authors: R.-M. Kling, P. Banerjee
Venue: Proceedings of the 24th ACM/IEEE Design Automation Conference (1987)

ESP (Evolution-based Standard cell Placement) is a new program package designed to perform standard cell placement and includes macro-block placement capabilities. It uses the new heuristic method of simulating an evolutionary process in order to minimize the cell interconnection wire length. While achieving results comparable to or better than the popular Simulated Annealing algorithm, ESP performs its task about ten times faster.
Storing the subdivision of a polyhedral surface
Authors: D Mount
Venue: Proceedings of the second annual symposium on Computational geometry (1986)

A common structure arising in computational geometry is the subdivision of a plane defined by the faces of a straight line planar graph. We consider a natural generalization of this structure on a polyhedral surface. The regions of the subdivision are bounded by geodesics on the surface of the polyhedron. A method is given for representing such a subdivision that is efficient both with respect to space and the time required to answer a number of different queries involving the subdivision. For example, given a point @@@@ on the surface of the polyhedron, the region of the subdivision containing x can be determined in logarithmic time. If n denotes the number of edges in the polyhedron, and m denotes the number of geodesics in the subdivision, then the space required by the data structure is &Ogr;((n + m) log (n + m)). Combined with existing algorithms for computing Voronoi diagrams on the surface of polyhedra, this structure provides an efficient solution to the nearest neighbor query problem on polyhedral surfaces.
(N, K) Concept Fault Tolerance
Authors: Thijs Krol
Venue: IEEE Transactions on Computers (1986)

This paper describes a new fault-tolerant computer architecture based on a "distributed implementation" of a symbol- error correcting code. In this, as at is called, (N, K) concept the faults are masked by this code. The (N, K) concept is described in detail for N = 4 and K = 2. It is shown that symbol-error correcting codes having additional bit-error correcting capabilities make additional memory protection by means of bit-error correcting codes superfluous and a newly designed symbol-and bit- error correcting code for the
Incomplete information and the join operation in database machines
Authors: A. R. Hurson, L. L. Miller, S. H. Pakzad
Venue: Proceedings of the 1987 Fall Joint Computer Conference on Exploring technology: today and tomorrow (1987)

The proliferation of data combined with higher performance requirements have forced designers of database systems to look beyond software solutions. Hardware approaches, namely database machines, have been introduced to overcome this problem. Most of the database machine designs have been based on the relational database model. The performance of these machines has been closely identified with the performance of the join operation. The recent discussion of null values and maybe algebra allows the user to examine potentially interesting data relationships based on part on unknown (incomplete) data. The work presented here examines the performance of a join module at the presence of incomplete data in the database. Four classes of join operations namely: True join, maybe join, attribute maybe join and outer join have been considered in this study. In addition, we will show that the enhanced join module does not sacrifice the performance of the true join operation.