ppxscal/embedding_network huggingface dataset:
Usable software in advanced educational computing projects
Authors: Mary E. Hopper
Venue: ACM SIGGRAPH Computer Graphics (1994)

Success in exploiting the potential of advanced computing systems that are currently emergning could depend upon how well we learn lessons from those who have already experimented with them. This was the purpose of the doctoral research study conducted by Mary Hopper of Purdue University, which is the subject of this paper. The following projects were the focus of this study: bull; Engineering Specific Career-Planning and Problem-Solving Environment, Educational Research and Information Systems, Purdue University bull; Context 32, Institute for Research in Information and Scholarship, Brown University bull; TODOR and Mechanics 2.01 Problem Set Solutions, Athena, Massachusetts Institute of Technology bull; The Physical Geology Tutor, Center for Educational Computing Initiatives, Massachusetts Institute of TechnologyInterviews with 19 key participants and information from major documents were used to construct a description of the relationships between educational goals and important technical characteristics. In each project, the predominant reason for the choice of software was based on the need to access the particular set of functions perceived to be most congenial to representing a specific academic body of knowledge. The following are the three main functions of computers which relate to improved representations of particular aspects of disciplines during this study: bull; Powerful database functions allowed for the inclusion and management of more extensive representations of the knowledge-base of the discipline bull; Multimedia functions allowed for more realistic and powerful representations of multimodal and experiential content bull; Microworlds were emphasized for their ability to provide students with the ability to interact with computational representations of dynamic systems and processesWhile each project began with a primary emphasis upon the particular type of software function they needed for the type of data to be represented, each project was eventually also constrained by a set of convergences and circumstances related to the question, "How can the software be more usable?" Some courseware projects in this study arrived at their answer to this question for practical reasons, while others arrived at it for educational reasons, but they all ended up appreciating the importance of usable educational software from both the learner's and author's perspective.
A variation of Knoop, Rüthing, and Steffen's Lazy Code Motion
Authors: Karl-Heinz Drechsler, Manfred P. Stadel
Venue: ACM SIGPLAN Notices (1993)

Morel and Renvoise discussed in 1979 a universal method for global code optimization in a compiler. By suppressing partial redundancies their method achieves several optimization techniques - such as moving loop invariant computations out of a loop or deleting redundant computations - at once. Their algorithm moves computations to earlier places in execution paths to eliminate partial redundancies. The movement is controlled by some heuristics.The heuristics and algorithms used by Morel and Renvoise sometimes cause difficulties for practical use. Subsequent papers partly circumvented these difficulties by slightly modifying the heuristics and the algorithms. Knoop, R uuml;thing, and Steffen published in their paper Lazy Code Motion an optimal algorithm for the elimination of partial redundancies which entirely prevents these difficulties. This paper presents a variant of their algorithm which is better prepared for practical use.
Computing a centerpoint of a finite planar set of points in linear time
Authors: Shreesh Jadhav, Asish Mukhopadhyay
Venue: Proceedings of the ninth annual symposium on Computational geometry (1993)

The notion of a centerpoint of a finite set of points in two and higher dimensions is a generalisation of the concept of the median of a (finite) set of points on the real line. In this paper, we present an algorithm for computing a centerpoint of a set of n points in the plane. The algorithm has complexity O(n) which significantly improves the O(n log3 n) complexity of the previously best known algorithm. We use suitable modifications of the ham-sandwich-cut algorithm and the prune-and-search technique to achieve this improvement.
From undo to multi-user applications: the demo
Authors: Michael Spenke
Venue: Proceedings of the INTERACT '93 and CHI '93 conference on Human factors in computing systems (1993)

The object-oriented history mechanism of the GINA application framework and its relevance for multi-user applications are demonstrated. The interaction history of a document is represented as a tree of command objects. Synchronous cooperation is supported by replicating the document state and exchanging command objects. Asynchronous cooperation leads to different branches of the history tree which can later be merged.
Measuring, monitoring and enforcing CPU execution time
Authors: A. Burns, A. J. Wellings
Venue: ACM SIGAda Ada Letters (1993)

Many real-time scheduling theories depend on the ability to measure or estimate the amount of CPU time processes require. Furthermore, they often required a limit to the amount of CPU time a process consumes at run-time. This paper considers the requirements these theories place on a language and its associated run-time support system. It also considers the extent to which Ada 9X meets these requirements.
Creating abstract superclasses by refactoring
Authors: William F. Opdyke, Ralph E. Johnson
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

This paper focuses on object-oriented programming and one kind of structure-improving transformation (refactoring) that is unique to object-oriented programming: finding abstract superclasses. We decompose the operation of finding an abstract superclass into a set of refactoring steps, and provide examples. We discuss techniques that can automate or automatically support these steps. We also consider some of the conditions that must be satisfied to perform a refactoring safely; sometimes to satisfy these conditions other refactorings must first be applied.
Provably good mesh generation
Authors: Marshall Bern, David Eppstein, John Gilbert
Venue: Journal of Computer and System Sciences (1994)

We study several versions of the problem of generating triangular meshes for finite element methods. We show how to triangulate a planar point set or polygonally bounded domain with triangles of bounded aspect ratio; how to triangulate a planar point set with triangles having no obtuse angles; how to triangulate a point set in arbitrary dimension with simplices of bounded aspect ratio; and how to produce a linear-size Delaunay triangulation of a multidimensional point set by adding a linear number of extra points. All our triangulations have size (number of triangles) within a constant factor of optimal and run in optimal time O(n log n + k) with input of size n and output of size k. No previous work on mesh generation simultaneously guarantees well-shaped elements and small total size.
A Unified Negative-Binomial Distribution for Yield Analysis of Defect-Tolerant Circuits
Authors: Israel Koren, Zahava Koren, Charles H. Stapper
Venue: IEEE Transactions on Computers (1993)

It has been recognized that the yield of fault-tolerant VLSI circuits depends on the size of the fault clusters. Consequently, models for yield analysis have been proposed for large-area clustering and small-area clustering, based on the two-parameter negative-binomial distribution. The addition of a new parameter, the block size, to the two existing parameters of the fault distribution is proposed. This parameter allows the unification of the existing models and, at the same time, adds a whole range of medium-size clustering models. Thus, the flexibility in choosing the appropriate yield model is increased. Methods for estimating the newly defined block size are presented and the approach is validated through simulation and empirical data.
Object extensibility: a Turbo Pascal graphics example
Authors: Chip Dixon
Venue: ACM SIGCSE Bulletin (1993)

This paper presents the object-oriented concept of extensibility. The specific implementation for this concept is the language Turbo Pascal (5.5 or later). The example illustrated has been successfully used as part of an introductory object-oriented programming class.
Factors that affect the adoption of distributed database management systems
Authors: Steven R. Gordon, Judith R. Gordon
Venue: Proceedings of the 1993 conference on Computer personnel research (1993)

A distributed database management system (DDBMS) offers an organization the ability to centralize or decentralize its management of data. In this paper we examine how the likelihood of DDBMS adoption is affected by four organizational factors, drawn from previous research and a pilot study conducted by the authors: (1) centralization - decentralization of management decision making; (2) centralization - decentralization of the information systems function; (3) attitudes of top management toward technology; and (4) forces behind information technology selection. We surveyed the chief information officers of 500 companies selected from the top Fortune industrials and the top Fortune service firms. Our results demonstrate that the decentralization of decision making, the decentralization of the information systems structure, and the attitudes of top management toward technology explain the propensity to adopt DDBMS; the locus of responsibility for driving the selection of information technology does not significantly explain DDBMS adoption in the way we hypothesized. Understanding an organization in terms of these factors is important in assessing the organization's readiness to adopt DDBMS technology and ability to use DDBMS successfully upon adoption.
Research perspectives for time series management systems
Authors: Werner Dreyer, Angelika Kotz Dittrich, Duri Schmidt
Venue: ACM SIGMOD Record (1994)

Empirical research based on time series is a data intensive activity that needs a data base management system (DBMS). We investigate the special properties a time series management system (TSMS) should have. We then show that currently available solutions and related research directions are not well suited to handle the existing problems. Therefore, we propose the development of a special purpose TSMS, which will offer particular modeling, retrieval, and computation capabilities. It will be suitable for end users, offer direct manipulation interfaces, and allow data exchange with a variety of data sources, including other databases and application packages. We intend to build such a system on top of an off-the-shelf object-oriented DBMS.
Compiling query constraints (extended abstract)
Authors: Peter J. Stuckey, S. Sudarshan
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

We present a general technique to push query constraints (such as length&le;1000) into database views and (constraint) logic programs. We introduce the notion of parametrized constraints, which help us push constraints with argument values that are known only at run time, and develop techniques for pushing parametrized constraints into predicate/view definitions. Our technique provides a way of compiling programs with constraint queries into programs with parametrized constraints compiled in, and which can be executed on systems, such as database query evaluation systems, that do not handle full constraint solving. Thereby our technique can push constraint selections that earlier constraint query rewriting techniques could not. Our technique is independent of the actual constraint domain, and we illustrate its use with equality constraints on structures (which are useful in object-oriented query languages) and linear arithmetic constraints.
Optimality of multi-domain protocols
Authors: Raphael Yahalom
Venue: Proceedings of the 1st ACM conference on Computer and communications security (1993)

Protocols which include key-distribution and data exchange phases in an asynchronous, shared key, multidomain environment are examined. A model of a distributed system is presented and the goals of the multidomain protocols are formulated. The minimal number of messages for two variants of such protocols is proved. Two multi-domain protocols which contain the minimal number of messages are presented. The results are compared with previously published work.
Original Contribution: The “off line learning approximation” in continuous time neural networks: An adiabatic theorem
Authors: Michel Benaim
Venue: Neural Networks (1993)

In this paper we consider the justification of the ''Off Line Approximation'' in continuous time neural networks from a rigorous mathematical point of view. In real time models, the behavior of a network is characterized by two distinct dynamics evolving according different time scales, the weight dynamics which are the ''slow'' and the activation dynamics which are the ''fast.'' The ''off-line approximation'' assumes that during the learning process, neural activities are in their steady states. Such an approximation is a common dogma often used to provide an analysis of network behavior. In this paper we consider convergent networks and prove that this approximation is valid on the time scale 1/@e where @e is the learning rate parameter which controls the learning velocity. We apply these results to prove the stability of Hebbian learning in a two-layered neural network which can be seen as a continuous time version of the self-organizing Kohonen's model.
On the Complexity of Bilinear Forms Over Associative Algebras
Authors: Nader H. Bshouty
Venue: SIAM Journal on Computing (1994)

Let $F$ be a field, and let $q(\alpha)=q_1^{d_1}(\alpha)\cdots q_k^{d_k}(\alpha)\in F[\alpha]$ be a polynomial of degree $n$, where $q_1(\alpha),\ldots,q_k(\alpha)$ are distinct irreducible polynomials. Let $y(\alpha),y_1(\alpha),\ldots,y_r(\alpha)$, $x_1(\alpha),\ldots,x_s(\alpha)$ be $(n-1)$-degree polynomials with distinct nonscalar coefficients. The authors show the following: the number of nonscalar multiplications/divisions required to compute the coefficients of $x_i(\alpha)y(\alpha)\ \mbox{mod}\ q(\alpha)$ for $i=1,\ldots,s$ by straight line algorithms is $s(2n-k)$. If $H$ is a $s\times r$- matrix with entries from $F$, then the number of nonscalar multiplications/ divisions required to compute the coefficients of $(x_1(\alpha),\ldots,x_s(\alpha)) $ $ H (y_1(\alpha),\ldots,$ $y_r(\alpha))^T \mbox{ mod } q(\alpha) $ by straight line algorithms is equal to $(2n-k)$rank$(H)$. All the above systems satisfy the direct sum conjecture strongly. The above results also hold for some other algebras that are direct sums of local algebras, such as commutative algebras and division algebras.
An Ada solution to the general mutual exclusion problem
Authors: Kwok-bun Yue
Venue: ACM SIGAda Ada Letters (1993)

Although some specific mutual exclusion problems have been studied extensively, automatic solutions to synchronize general mutual exclusion problems with arbitrary mutual exclusion constraints have not been fully explored. This paper discusses an Ada 83 solution that can be applied to any general mutual exclusion problem. This solution is based on strong binary semaphores. A generic package is used to generate the solution for an given mutual exclusion problem. An Ada program for the simulation of the classical Dining Philosophers Problem is presented as an example to demostrate how the solution can be used.
One-Bit Delay in Ring Networks
Authors: Reuven Cohen
Venue: IEEE Transactions on Computers (1993)

In local area networks (LANs) with ring topologies, it is important to have minimum delay at the stations. It is explained why one-bit delay is the minimum possible delay at each station. It is shown that the stations delay depends on the medium access control (MAC) protocol executed in the ring. As an example, a recently published MAC protocol for rings is considered. It is explained why this protocol cannot be implemented with one-bit delay shown how a small modification in the slot format enables the implementation of the protocol with one-bit delay without affecting its properties.
Open OODB: a modular object-oriented DBMS
Authors: Steve Ford, José A. Blakeley, Thomas J. Bannon
Venue: Proceedings of the 1993 ACM SIGMOD international conference on Management of data (1993)

The Open OODB project, part of the DARPA Persistent Object Base (POB) Program, is an effort to build an open, extensible object-oriented database management system (OODB) in which database functionality can be tailored for particular applications within an incrementally improvable framework. The system is designed to serve both as a platform for research and as a testbed that can meet the needs of demanding, next generation database applications. The Open OODB project goals are to describe the design space of OODBs; build an architectural framework that enables configuring independently useful modules to form an OODB; verify the suitability of this open approach by implementing an OODB to these specifications; and identify opportunities for building consensus that can lead to much-needed OODB standards. The motivating factors in this approach were that our previous experience in object-oriented databases had convinced us that different applications have differing requirements, and that a monolithic system is unlikely to meet the needs of many demanding kinds of applications.
Role-based security: pros, cons, some research directions
Authors: Matunda Nyanchama, Sylvia Osborn
Venue: ACM SIGSAC Review (1993)

User role-based protection presents a flexible (hence adaptive) means for enforcing differing ranges of security policies. It can emulate both mandatory and discretionary access control modes of protection. Role-based protection enforces the principle of least privilege, hence minimizing the risk of Trojan horse attacks. This paper offers a glimpse into the strengths (and some weaknesses) of role-based protection, the structures for its enforcement and pointers to the direction for future research.
Talking about modules and delivery
Authors: Harley Davis, Pierre Parquier, Nitsan Séniak
Venue: Proceedings of the 1994 ACM conference on LISP and functional programming (1994)

Adding a module system to LISP enhances program security and efficiency, and help the programmer master the complexity of large systems, thus facilitating application and delivery. TALK's module system is based on a simple compilation model which takes macros into account and provides a solid basis for automatic module management tools. Higher-level structuring entities&mdash;libraries and executables&mdash;group modules into deliverable goods. The module system is secure because it validates interfaces, efficient because it separates compilation dependencies from execution dependencies, and useful because it offers a simple processing model, automatic tools, and a graceful transition from development to delivery.
APL programming without tears: it is time for a change
Authors: P. Naeve, B. Strohmeier, P. Wolf
Venue: ACM SIGAPL APL Quote Quad (1993)

To overcome the unreadability of traditional APL-code Knuth's idea of literate programming is adapted to APL. The APL2web system of structured documentation is introduced as a new way of APL-programming. An example is given to highlight the merits of this combination.
Towards a unified visual database access
Authors: K. Vadaparty, Y. A. Aslandogan, G. Ozsoyoglu
Venue: ACM SIGMOD Record (1993)

Since the development of QBE, over fifty visual query languages have been proposed to facilitate easy database access. Although these languages have introduced some very useful paradigms, a number of these have some severe limitations, such as: (a) not extending beyond the relational model (b) not considering negation and safety, formally (c) using ad hoc constructs, with no analysis of expressivity or complexity done, etc. Note that visual database access is an important issue being revisted, with the emergence of different flavors of object-oriented databases. We believe that there is a need for developing a unified visual query language. Specifically, our goal is to develop a visual query language that has the following properties: (i) It has a few core constructs using which &ldquo;expert-users&rdquo; can define new (derived) constructs easily (ii) &ldquo;Normal users&rdquo; can use easily either the core or the derived constructs for database querying (iii) It can implement representative constructs of other (textual or visual) query language straightforwardly, and (iv) It has formal semantics, with its theoretical properties, such as complexity, analyzed. We believe that we make a first step towards the above goal by introducing a new logical construct called restricted universal quantifier and combining it with the hierarchical structure of windows to develop a Visual Query Language, called VQL. The core constructs of VQL can encode easily a number of representative constructs of different (about six visual and four non-visual) relational, nested and object-oriented query languages. We also study the theoretical aspects such as safety, complexity, etc., of VQL.
The missing link in requirements engineering
Authors: Hermann Kaindl
Venue: ACM SIGSOFT Software Engineering Notes (1993)

Especially the early phase of requirements engineering is one of the most important and least supported parts of the software life cycle. Since pure natural language has its disadvantages, and directly arriving at a formal representation is very difficult, a link through a mediating representation is missing. We use hypertext for this purpose, providing also links among requirements statements and the representation of objects in a domain model. This possibility of explicit representation of links allows the users and analysts to make relationships and dependencies explicit and helps to be aware of them. Actually, our approach and the tool supporting it use a combination of various technologies, including also object-oriented approaches and a grain of artificial intelligence (in particular frames). Therefore, inheritance is provided by our tool already in the early phase of requirements engineering. In particular, we found it very useful to view requirements as objects. A key idea is to support the ordering of ideas especially through classification already in the early stages. While our approach is not intended to substitute useful existing techniques emphasizing more formal representations, it can be combined with them.
Technology and pedagogy for collaborative problem solving as a context for learning
Authors: Timothy Koschmann, Denis Newman, Earl Woodruff, Roy Pea, Peter Rowley
Venue: ACM SIGCHI Bulletin (1993)

This workshop, sponsored jointly by CSCW'92 and the Centre for Applied Cognitive Science at the Ontario Institute for Studies in Education (OISE), was organized to bring together researchers with interests in the emerging area of Computer Support for Collaborative Learning (CSCL). It was held at OISE on the weekend preceding CSCW'92 and was attended by 27 participants from academia and industry.