ppxscal/embedding_network huggingface dataset:
Sigmoid Generators for Neural Computing Using Piecewise Approximations
Authors: Ming Zhang, Stamatis Vassiliadis, José G. Delgado-Frias
Venue: IEEE Transactions on Computers (1996)

A piecewise second order approximation scheme is proposed for computing the sigmoid function. The scheme provides high performance with low implementation cost; thus, it is suitable for hardwired cost effective neural emulators. It is shown that an implementation of the sigmoid generator outperforms, in both precision and speed, existing schemes using a bit serial pipelined implementation. The proposed generator requires one multiplication, no look-up table and no addition. It has been estimated that the sigmoid output is generated with a maximum computation delay of 21 bit serial machine cycles representing a speedup of 1.57 to 2.23 over other proposals.
The use of cellular automata in the classroom
Authors: H. Albert Lilly
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

The paper explains what a cellular automaton is and why schools would want to integrate the study of cellular automata into their curricula. Examples are given and suggestions for sample exercises follow. Each example is given a title, a discipline to which it relates, a source from which the example or the motivation for the example was taken, and a recommended grade level--middle school or high school. Source code in Microsoft's FORTRAN PowerStation, Version 1.0 is available for all of the examples. Each of the programs show a visualization of a particular cellular automaton over time. A cellular automaton is a modeling tool that can be used in the classroom with either pencil and paper or on computers. Cellular automata can be important in motivating students, reaching students with certain learning styles, helping students develop modeling skills, and in the development of curricula for teaching certain computer technologies.
Is GUI programming a database research problem?
Authors: Nita Goyal, Charles Hoch, Ravi Krishnamurthy, Brian Meckler, Michael Suckow
Venue: ACM SIGMOD Record (1996)

Programming nontrivial GUI applications is currently an arduous task. Just as the use of a declarative language simplified the programming of database applications, we ask whether we can do the same for GUI programming? Can we then import a large body of knowledge from database research? We answer these questions by describing our experience in building nontrivial GUI applications initially using C++ programming and subsequently using Logic++, a higher order Horn clause logic language on complex objects with object-oriented features. We abstract a GUI application as a set of event handlers. Each event handler can be conceptualized as a transition from the old screen/program state to a new screen/program state. We use a data centric view of the screen/program state (i.e., every entity on the screen corresponds to proxy datum in the program) and express each event handler as a query dependent update, albeit a complicated one. To express such complicated updates we use Logic++. The proxy data are expressed as derived views that are materialized on the screen. Therefore, the system must be active in maintaining these materialized views. Consequently, each event handler is conceptually an update followed by a fixpoint computation of the proxy data. Based on our experience in building the GUI system, we observe that many database techniques such as view maintenance, active DB, concurrency control, recovery, optimization as well as language concepts such as higher order logic are useful in the context of GUI programming.
Managing user perceptions of email privacy
Authors: Suzanne P. Weisband, Bruce A. Reinig
Venue: Communications of the ACM (1995)

Email users, expecting privacy, risk embarassment, lawsuits, and worse.
Preparation for research: instruction in interpreting and evaluating research
Authors: Alan Fekete
Venue: Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education (1996)

Traditional curricula have concentrated on teaching students the content of a subject; however, it has recently become apparent that effective education needs to include explicit instruction in many of the auxiliary skills and attitudes needed for the content to be useful. This applies just as much at advanced levels as at introductory ones, though the impact on teaching practice is not yet widespread. This paper describes an innovative module taught to students who are about to commence research, in which these students are given explicit guidance on how to judge the work of others (or their own work). The module is provided to undergraduates intending to perform an "Honours" research project in their final year; however, the material would also be relevant to students in a graduate program or senior seminar.
Introduction to witness and linking to process mapping tools
Authors: W. Bruce Thompson
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The paper describes AT&T Istel's WITNESS visual interactive simulator. The benefits of using WITNESS are described and illustrated by explaining the steps required to build any WITNESS model. Also described is the creation of WITNESS models from the ProSim process mapping tool.
An empirical study of algorithms for point-feature label placement
Authors: Jon Christensen, Joe Marks, Stuart Shieber
Venue: ACM Transactions on Graphics (TOG) (1995)

A major factor affecting the clarity of graphical displays that include text labels is the degree to which labels obscure display features (including other labels) as a result of spatial overlap. Point-feature label placement (PFLP) is the problem of placing text labels adjacent to point features on a map or diagram so as to maximize legibility. This problem occurs frequently in the production of many types of informational graphics, though it arises most often in automated cartography. In this paper we present a comprehensive treatment of the PFLP problem, viewed as a type of combinatorial optimization problem. Complexity analysis reveals that the basic PFLP problem and most interesting variants of it are NP-hard. These negative results help inform a survey of previously reported algorithms for PFLP; not surprisingly, all such algorithms either have exponential time complexity or are incomplete. To solve the PFLP problem in practice, then, we must rely on good heuristic methods. We propose two new methods, one based on a discrete form of gradient descent, the other on simulated annealing, and report on a series of empirical tests comparing these and the other known algorithms for the problem. Based on this study, the first to be conducted, we identify the best approaches as a function of available computation time.
Specifying a Safety-Critical Control System in Z
Authors: Jonathan Jacky
Venue: IEEE Transactions on Software Engineering (1995)

This paper presents a formal specification in the Z notation for a safety-critical control system. It describes a particular medical device but is quite generic and should be widely applicable. The specification emphasizes safety interlocking and other discontinuous features that are not considered in classical control theory. A method for calculating interlock conditions for particular operations from system safety assertions is proposed; it is similar to ordinary Z precondition calculation, but usually results in stronger preconditions. The specification is presented as a partially complete framework that can be edited and filled in with the specific features of a particular control system. Our system is large but the specification is concise. It is built up from components, subsystems, conditions and modes that are developed separately, but also accounts for behaviors that emerge at the system level. The specification illustrates several useful idioms of the Z notation, and demonstrates that an object-oriented specification style can be expressed in ordinary Z.
Fast floating-point processing in Common Lisp
Authors: Richard J. Fateman, Kevin A. Broughan, Diane K. Willcock, Duane Rettig
Venue: ACM Transactions on Mathematical Software (TOMS) (1995)

Lisp, one of the oldest higher-level programming languages, has rarely been used for fast numerical (floating-point) computation. We explore the benefits of Common Lisp, an emerging new language standard with some excellent implementations, for numerical computation. We compare it to Fortran in terms of the speed of efficiency of generated code, as well as the structure and convenience of the language. There are a surprising number of advantages to Lisp, especially in cases where a mixture of symbolic and numeric processing is needed.
An execution model for limited ambiguity rules and its application to derived data update
Authors: I.-Min A. Chen, Richard Hull, Dennis McLeod
Venue: ACM Transactions on Database Systems (TODS) (1995)

A novel execution model for rule application in active databases is developed and applied to the problem of updating derived data in a database represented using a semantic, object-based database model. The execution model is based on the use of &ldquo;limited ambiguity rules&rdquo; (LARs), which permit disjunction in rule actions. The execution model essentially performs a breadth-first exploration of alternative extensions of a user-requested update. Given an object-based database schema, both integrity constraints and specifications of derived classes and attributes are compiled into a family of limited ambiguity rules. A theoretical analysis shows that the approach is sound: the execution model returns all valid &ldquo;completions&rdquo; of a user-requested update, or terminates with an appropriate error notification. The complexity of the approach in connection with derived data update is considered.
Using Discriminant Eigenfeatures for Image Retrieval
Authors: Daniel L. Swets, John Weng
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

This paper describes the automatic selection of features from an image training set using the theories of multidimensional discriminant analysis and the associated optimal linear projection. We demonstrate the effectiveness of these Most Discriminating Features for view-based class retrieval from a large database of widely varying real-world objects presented as "well-framed" views, and compare it with that of the principal component analysis.
Conversational conventions and participation in cross-functional design teams
Authors: Eleanor Wynn, David G. Novick
Venue: Proceedings of conference on Organizational computing systems (1995)

The benefit of participatory teams&mdash;their cross-functional and diverse nature&mdash;presents a converse challenge to communicate in a common &ldquo;language&rdquo;, using shared conventions, against the backdrops of an unfamiliar speech context and the tacit organizational social structure. This paper employs constructs from several language-use theories to identify mismatched conventions and consequent confusion that impede or inhibit full participation in settings like system design or work-process redesign.
An exact methodology for scheduling in a 3D design space
Authors: Samit Chaudhuri, Stephen A. Blythe, Robert A. Walker
Venue: Proceedings of the 8th international symposium on System synthesis (1995)

Abstract: This paper describes an exact solution methodology, implemented in Rensselaer's Voyager design space exploration system, for solving the scheduling problem in a 3-dimensional (3D) design space: the usual 2D design space (which trades off area and schedule length), plus a third dimension representing clock length. Unlike design space exploration methodologies which rely on bounds or estimates, this methodology is guaranteed to find the globally optimal solution to the 3D scheduling problem. Furthermore, this methodology efficiently prunes the search space, eliminating provably inferior design points through: a careful selection of candidate clock lengths; and tight bounds on the number of functional units of each type or on the schedule length.
Thinking about binary trees in an object-oriented world
Authors: A. Michael Berman, Robert C. Duvall
Venue: Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education (1996)

The Binary Search Tree serves as an important example when teaching data structures. We explore new approaches to understanding the implementation of a Binary Search Tree, using concepts from Object-Oriented Programming and C++. The Binary Search Tree illustrates how adopting a new approach and a new language can lead to a new way of thinking about a familiar problem.
Queueing model with state dependent balking and reneging: its complementary and equivalence
Authors: Surendra M. Gupta
Venue: ACM SIGMETRICS Performance Evaluation Review (1995)

In this paper, the concepts of complementarity and equivalence between an M/M/c/K queueing model with state dependent balking and reneging and a machine interference problem with warm standbys are formalized. The relationship provides insight into these queueing systems. Through a series of corollaries, relationships between various queueing systems are derived. It is shown that a recently reported relationship between Erlang loss system and a finite source queueing system is a trivial consequence of the more general results presented here. New results involving the arrival point probabilities and measures of performance for these two queueing systems are also presented. An example is also provided.
Using HyTime for modeling publishing workflows
Authors: Franz Burger, Gerald Quirchmayr, Siegfried Reich, A. Min Tjoa
Venue: ACM SIGOIS Bulletin (1995)

Workflow Management is seen as the key for improving overall businesseffectiveness. However, today's solutions are very specific and isolated. Recently emerged international standards in the publishing sector providethe means for enabling standardized descriptions and thus allow theinterchange and reuse of workflow information. This paper describes howHyTime can be used as a modeling language to describe publishing workflows. We present relevant parts of the HyTime model and reflect on pros and consof the chosen approach.
Note on the end game in homotopy zero curve tracking
Authors: Maria Sosonkina, Layne T. Watson, David E. Stewart
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

Homotopy algorithms to solve a nonlinear system of equations f(x) = 0 involve tracking the zero curve of a homotopy map p(a, &lgr;, x) from &lgr; = 0 until &lgr; = 1. When the algorithm nears or crosses the hyperplane &lgr; = 1, an &ldquo;end game&rdquo; phase is begun to compute the solution x&macr; satisfying p(a, &lgr;, x&macr;) = f(x&macr;) = 0. This note compares several end game strategies, including the one implemented in the normal flow code FIXPNF in the homotopy software package HOMPACK.
Greed sort: optimal deterministic sorting on parallel disks
Authors: Mark H. Nodine, Jeffrey Scott Vitter
Venue: Journal of the ACM (JACM) (1995)

We present an algorithm for sorting efficiently with parallel two-level memories. Our main result is an elegant, easy-to-implement, optimal, deterministic algorithm for external sorting with D disk drives. This result answers in the affirmative the open problem posed by Vitter and Shriver of whether an optimal algorithm exists that is deterministic. Our measure of performance is the number of parallel input/output (I/O) operations, in which each of the D disks can simultaneously transfer a block of B contiguous records. We assume that internal memory can hold M records. Our algorithm sorts N records in the optimal bound of &thgr;((N/BD) log(N/B)/ log(M/B)) deterministically, and thus improves upon Vitter and Shriver's optimal randomized algorithm as well as the well-known deterministic but nonoptimal technique of disk striping. It is also practical to implement.
Building personal digital libraries from network sources
Authors: Dion Goh, Chuck Kacmar
Venue: ACM SIGWEB Newsletter (1995)

Our work is focused on personal digital libraries and personal information spaces. In this context, a personal digital library (PDL) is a collection of multimedia objects (text, graphics and audio), created by an individual and/or drawn from resources elsewhere on the Internet. The benefits of this approach include a reduction in user disorientation and an increased likelihood that the user will find relevant material since the structure of the information space is defined and customized entirely by the user. This is achieved through metadata and cataloging facilities which allow for the creation and maintenance of the personal digital library.
A reexamination of &ldquo;Optimization of array subscript range checks&rdquo;
Authors: Wei-Ngan Chin, Eak-Khoon Goh
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1995)

Jonathan Asuru proposed recently an enhanced method for optimizing array subscript range checks. The proposed method is however unsafe and may generate optimized programs whose behavior is different from the original program. Two main flaws in Asuru's method are described, together with suggested remedies and improvements.
On the Index of Block Upper Triangular Matrices
Authors: Rafael Bru, Joan Josep Climent, Michael Neumann
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

Let $M$ be an upper block triangular matrix with $A$ and $B$ singular diagonal blocks. It is known that $\max\{\index (A), \index (B)\} \le \index (M) \le \index (A) + \index (B)$. Recently, a necessary and sufficient condition has been given so that $\index (M) = \index (A) + \index (B)$. In this paper we find various characterizations for $\index (M)$ to take any specific values between $\max\{\index (A), \index (B)\}$ and $\index (A) + \index (B)$ which generalize previous results.
The key to object-oriented simulation: separating the user and the developer
Authors: Pete Ball, Doug Love
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Simulation tools should be both easy to use and applicable to a wide range of problems. In practice, however, a compromise exists giving rise to a range of software from simulators to simulation languages. Object-oriented techniques have the potential to overcome this compromise; the ability to reuse and extend software could enable the development of a simulator that would be extended over time. The use of object-oriented techniques to date has mainly resulted in the development of powerful but difficult to use libraries. Ideally the skills of manufacturing engineers should be concentrated on building models of manufacturing systems whilst the skills of software developers should be concentrated on adding new functionality. This paper presents a mechanism whereby the roles of engineer and developer are clearly split to provide an easy to use simulator with a potentially very wide range of application.
Infrastructure for rapid execution of strike-planning systems
Authors: Darrin West, John Cleary, Jim Hofmann, Larry Mellon, Jim Ramsey
Venue: Proceedings of the 27th conference on Winter simulation (1995)

A rapid-planning system for military aircraft strikes is under design. It is intended to be capable of creating aircraft routes through enemy and friendly space with minimum loss of aircraft and maximal damage to specified target areas. The system must support joint strike planning, where the effects of several simultaneous strikes by differing groups of aircraft are captured. This paper describes a three-phased approach to the analysis of routes: static analysis to establish potential routes, detailed simulation to capture dynamic behaviors in the system, and human-in-the-loop evaluation of the most promising routes. A parallel, discrete-event simulation technique is proposed to support the detailed simulation. Optimizations based on application characteristics are described. A technique to combine discrete-event and time-stepped models is proposed. Performance results of the current simulation engine are given.
Using nonparametric statistics in simulation analysis: a review
Authors: Enver Yücesan
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Techniques that make the minimum of assumptions about the underlying characteristics of the simulation output series are particularly useful for simulation analysis. This tutorial discusses robust non-parametric techniques with immediate applicability to such crucial steps in simulation analysis as sampling, experimental design, and output analysis. Algorithms are provided for various tasks.
On the signature weight in &ldquo;multiple&rdquo; m signature files
Authors: Fabio Grandi
Venue: ACM SIGIR Forum (1995)

This paper deals with the estimation of the signature weight as generated by the superimposed coding technique adopted in "multiple" m signature files. The estimation is needed for performance evaluation of such organizations used for information retrieval applications. In particular, simple formulas for the probability density function, the expected value and the variance of the signature weight are presented.The presented formulas can be derived following a general methodology we called the gamma;-transform approach in a previous work, which results much more simple than the method used by other authors for the derivation of the density function. Equivalence of the results is also shown.
A Hierarchical Approach to Parallel Multiquery Scheduling
Authors: Joel L. Wolf, John Turek, Ming-Syan Chen, Philip S. Yu
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

There has been a good deal of progress made recently toward the efficient parallelization of individual phases of single queries in multiprocessor database systems. In this paper we devise and experimentally evaluate a number of scheduling algorithms designed to handle multiple parallel queries. (Scheduling in this context implies the determination of both processor allotments and temporal processor assignments to individual queries and query phases.) One of these algorithms performs the best in our experiments. This algorithm is hierarchical in nature: In the first phase, a good quality precedence-based schedule is created for each individual query and each possible number of processors. This component employs dynamic programming. In the second phase, the results of the first phase are used to create an overall schedule of the full set of queries. This component is based on previously published work on nonprecedence-based malleable scheduling. Even though the problem we are considering is NP-hard in the strong sense, the multiple query schedules generated by our hierarchical algorithm are seen experimentally to achieve high quality results.
Efficient Algorithms for the Hitchcock Transportation Problem
Authors: Takeshi Tokuyama, Jun Nakano
Venue: SIAM Journal on Computing (1995)

We consider the Hitchcock transportation problem on $n$ supply points and $k$ demand points when $n$ is much greater than $k$. The problem can be solved in $O(k n^2 \log n + n^2 \log^2 n)$ time if an efficient minimum-cost flow algorithm is directly applied. Applying a geometric method named splitter finding and a randomization technique, we can improve the time complexity when the ratio $c$ of the maximum supply to the minimum supply is sufficiently small. The expected running time of our randomized algorithm is $O(\frac{kn \log cn}{\log (n/k^4 \log^{2}k)})$ if $n > k^4 \log^{2} k$, and $O(k^5 \log^{2} n \log cn)$ if $n \le k^4 \log^{2} k$. If $n = \Omega(k^{4 + \epsilon})\ (\epsilon > 0)$ and $c = \mbox{poly}(n)$, the problem is solved in $O(kn)$ time, which is optimal.