ppxscal/embedding_network huggingface dataset:
Locus of feedback control in computer-based tutoring: impact on learning rate, achievement and attitudes
Authors: Albert T. Corbett, John R. Anderson
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2001)

The advent of second-generation intelligent computer tutors raises an important instructional design question: when should tutorial advice be presented in problem solving? This paper examines four feedback conditions in the ACT Programming Tutor. Three versions offer the student different levels of control over error feedback and correction: (a) immediate feedback and immediate error correction; (b) immediate error flagging and student control of error correction; (c) feedback on demand and student control of error correction. A fourth, No-tutor condition offers no stepby-step problem solving support. The immediate feedback group with greatest tutor control of problem solving yielded the most efficient learning. These students completed the tutor problems fastest, and the three tutor-supported groups performed equivalently on tests. Questionnaires revealed little student preference among the four conditions. These results suggest that students will need explicit guidance to benefit from learning opportunities that arise when they have greater control over tutorial assistance.
A student project in software evaluation
Authors: Michael F. Czajkowski, Cheryl V. Foster, Thomas T. Hewett, Joseph A. Casacio, William C. Regli, Heike A. Sperber
Venue: ACM SIGCSE Bulletin (2001)

Properly educating computer scientists involves teaching effective means to properly engineer a system. An important part of such engineering work is ensuring that the computing system is both useful and usable. While many systems out there today are difficult to use, performing usability engineering on a system during its development has been shown to be an effective way to make a system more usable. The problem is fitting practical experience into the curriculum. This paper discusses a case example of how a team of undergraduate students learned to take a software system during its developing stages and perform effective usability engineering following the "thinking out loud" methodology.
The structure of &ldquo;THE&rdquo;-multiprogramming system
Authors: Edsger W. Dijkstra
Venue: Communications of the ACM (1983)

A multiprogramming system is described in which all activities are divided over a number of sequential processes. These sequential processes are placed at various hierarchical levels, in each of which one or more independent abstractions have been implemented. The hierarchical structure proved to be vital for the verification of the logical soundness of the design and the correctness of its implementation.
ADA:: past, present, future
Authors: Jean Ichbiah
Venue: Communications of the ACM (1984)

Since the mid-1970s, the U.S. Department of Defense has been laying the groundwork for a major new computer language that may substantially displace FORTRAN and COBOL in the years ahead. With Ada just now starting to be used, Communications felt it would be timely to conduct an interview with Jean Ichbiah, the principal designer of this new language. Ichbiah discusses the evolution of Ada, evaluates its success so far, and speculates on its future.
A comparison of the correlational behavior of random number generators for the IBM 360
Authors: John RB Whittlesey
Venue: Communications of the ACM (1968)

Hutchinson states that the &ldquo;new&rdquo; (prime modulo) multiplicative congruential pseudorandom generator, attributed to D.H. Lehmer, has passed the usual statistical tests for random number generators. It is here empirically shown that generators of this type can produce sequences whose autocorrelation functions up to lag 50 exhibit evidence of nonrandomness for many multiplicative constants. An alternative generator proposed by Tausworthe, which uses irreducible polynomials over the field of characteristic two, is shown to be free from this defect. The applicability of these two generators to the IBM 360 is then discussed. Since computer word size can affect a generator's statistical behavior, the older mixed and simple congruential generators, although extensively tested on computers having 36 or more bits per word, may not be optimum generators for the IBM 360.
Math proficiency: a key to success for computer science students
Authors: John Konvalina, Stanley A. Wileman, Larry J. Stephens
Venue: Communications of the ACM (1983)

A computer science aptitude predictor was administered to students enrolled in a first technical course in computer science to determine potential for success. The study revealed significant differences in the scoring between students who withdrew from the course and those students who did not. The causes for the differences all related to the students' mathematical background: high school performance, previous computer science education, and the number of college mathematics courses taken.
Minimax Controls for Uncertain Parabolic Systems
Authors: Nadir Arada, Maïtine Bergounioux, Jean-Pierre Raymond
Venue: SIAM Journal on Control and Optimization (2000)

We consider systems governed by a nonlinear parabolic equation with a distributed control and a disturbance in the initial condition. We prove the existence of solutions to a corresponding minimax problem, and we obtain necessary optimality conditions in the form of Pontryagin's principles.
Search and strategies in OPL
Authors: Pascal Van Hentenryck, Laurent Perron, Jean-François Puget
Venue: ACM Transactions on Computational Logic (TOCL) (2000)

OPL is a modeling language for mathematical programming and combinatorial optimization. It is the first language to combine high-level algebraic and set notations from mathematical modeling languages with a rich constraint language and the ability to specify search procedures and strategies that are the essence of constraint programming. This paper describes the facilities available in OPL to specify search procedures. It describes the abstractions of OPL to specify both the search tree (search) and how to explore it (strategies). The paper also illustrates how to use these high-level constructs to implement traditional search procedures in constraint programming and scheduling.
A new radiosity approach by procedural refinements for realistic image sythesis
Authors: Min-Zhi Shao, Qun-Sheng Peng, You-Dong Liang
Venue: ACM SIGGRAPH Computer Graphics (1988)

According to the rendering equation, the diffuse and the specular components of the outgoing intensity of each surface patch should be solved simultaneously. Rather than establishing a huge set of linear equations defining the unknown directional intensities for all directions and all surface patches, we expand the concept of the delta form-factor which concerns the light energy transfer of a surface patch along a respective direction. As the delta form-factor for non-diffuse surface patches are dependent on the spatial and spectral distributions of light energy, they could not be calculated geometrically. In this paper, we present a new radiosity approach which progressively approximates the delta form-factors and the light energy distributions within a general environment to the correct solution. The nucleus of our approach is procedural iteration. Statistics indicate the potentials of this method for complex non-diffuse environments.
In search of multiple domain key recovery
Authors: Lars R. Knudsen, Keith M. Martin
Venue: Journal of Computer Security (1998)

Key recovery systems suitable for application among multiple domains, such as those operating within international communication networks, are investigated. A general framework for analysis of key recovery systems is introduced and a set of parameters appropriate for multiple domain key recovery is established. Three key recovery techniques are identified. It is shown that use of just one of these key recovery techniques is not sufficient for key recovery requirements among multiple domains. Further, it is shown that even key recovery systems using a combination of these techniques involve a complex tradeoff between cryptographic flexibility, system complexity and overall soundness. This forms a major technical difficulty in the search for a satisfactory system design.
Modeling multipath fading channel dynamics for packet data performance analysis
Authors: Young Yong Kim, San-qi Li
Venue: Wireless Networks (2000)

The multipath fading channel modeling traditionally focuses on physical level dynamics such as signal strength and bit error rate. In this paper we characterize multipath fading channel dynamics at the packet level and analyze the corresponding data queueing performance in various environments. The integration of wireless channel modeling and data queueing analysis provides us a unique way to capture important channel statistics with respect to various wireless network factors such as channel bandwidth, mobile speed and channel coding. The second order channel statistics, i.e. channel power spectrum, is found to play an important role in the modeling of multipath fading channels. The data queueing performance is largely dependent on the interaction between the channel power spectrum and the data arrival power spectrum; whichever has lower frequency power will have more impact on queueing performance. Note that the data arrival power spectrum provides a measure of burstiness and correlation behavior of data packet arrivals. Throughout the paper, we use the Markov chain modeling technique to match the measured important channel statistics for both channel modeling and queueing analysis.
Universal Data Compression Based on the Burrows-Wheeler Transformation: Theory and Practice
Authors: Bernhard Balkenhol, Stefan Kurtz
Venue: IEEE Transactions on Computers (2000)

A very interesting recent development in data compression is the Burrows-Wheeler Transformation [1]. The idea is to permute the input sequence in such a way that characters with a similar context are grouped together. We provide a thorough analysis of the Burrows-Wheeler Transformation from an information theoretic point of view. Based on this analysis, the main part of the paper systematically considers techniques to efficiently implement a practical data compression program based on the transformation. We show that our program achieves a better compression rate than other programs that have similar requirements in space and time.
White paper on integrated broadband environment environment for personalized TV experience (IBEX)-preliminary edition
Authors: Yoshihisa Gonno, Fumihiko Nishio, Tomohiro Tsunoda, Yasuaki Yamagishi
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

This document intends to describe a system overview of &ldquo;Integrated Broadband Environment for Personalized TV Experience (IBEX)&rdquo;. The IBEX features three major goals: to release audience from time constraint scheduled by broadcasters, to provide seamless and adaptive access between TV and the Web, and finally, to securely personalize TV experience for individual audience. In order to achieve open framework, these viewpoints must be properly developed in conjunction with well-organized data models and system architecture based on de-facto standard technology. The IBEX will provide a prototype system model built on upcoming integrated broadband digital TV infrastructure. The IBEX also intends to provide a service model for the TV-Anytime framework.
On tiling space-time mapped loop nests
Authors: Martin Griebl
Venue: Proceedings of the thirteenth annual ACM symposium on Parallel algorithms and architectures (2001)

Automatic parallelization of loop programs based on space-time mapping typically aims at maximal parallelism. In order to obtain reasonable performance, the granularity of the parallelism must be coarsened, e.g., by applying tiling techniques. In contrast to others, we suggest to apply tiling after the computation of a space-time mapping. This extends the applicability of existing tiling methods and significantly improves efficiency of parallelized loop programs.
A Handwritten Numeral Character Classification Using Tolerant Rough Set
Authors: Daijin Kim, Sung-Yang Bang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

This paper proposes a new data classification method based on the tolerant rough set that extends the existing equivalent rough set. Similarity measure between two data is described by a distance function of all constituent attributes and they are defined to be tolerant when their similarity measure exceeds a similarity threshold value. The determination of optimal similarity threshold value is very important for the accurate classification. So, we determine it optimally by using the genetic algorithm (GA), where the goal of evolution is to balance two requirements such that 1) some tolerant objects are required to be included in the same class as many as possible and 2) some objects in the same class are required to be tolerable as much as possible. After finding the optimal similarity threshold value, a tolerant set of each object is obtained and the data set is grouped into the lower and upper approximation set depending on the coincidence of their classes. We propose a two-stage classification method that all data are classified by using the lower approximation at the first stage and then the nonclassified data at the first stage are classified again by using the rough membership functions obtained from the upper approximation set. We apply the proposed classification method to the handwritten numeral character classification problem and compare its classification performance and learning time with those of the feedforward neural network's backpropagation algorithm.
Tolerating Multiple Faults in Multistage Interconnection Networks with Minimal Extra Stages
Authors: Chenggong Charles Fan, Jenoshua Bruck
Venue: IEEE Transactions on Computers (2000)

In their 1982 paper, Adams and Siegel proposed an Extra Stage Cube Interconnection Network that tolerates one switch failure with one extra stage. We extend their results and discover a class of Extra Stage Interconnection Networks that tolerate multiple switch failures with a minimal number of extra stages. Adopting the same fault model as Adams and Siegel, the faulty switches can be bypassed by a pair of demultiplexer/multiplexer combinations. It is easy to show that, to maintain point to point and broadcast connectivities, there must be at least $f$ extra stages to tolerate $f$ switch failures. We present the first known construction of an Extra Stage Interconnection Network that meets this lower-bound. This $n$-dimensional Multistage Interconnection Network has $n+f$ stages and tolerates $f$ switch failures. An n-bit label called mask is used for each stage that indicates the bit differences between the two inputs coming into a common switch. We designed the fault-tolerant construction such that it repeatedly uses the singleton basis of the $n$-dimensional vector space as the stage mask vectors. This construction is further generalized and we prove that an $n$-dimensional Multistage Interconnection Network is optimally fault-tolerant if and only if the mask vectors of every n consecutive stages span the $n$-dimensional vector space.
Checking equivalence for partial implementations
Authors: Christoph Scholl, Bernd Becker
Venue: Proceedings of the 38th annual Design Automation Conference (2001)

We consider the problem of checking whether a partial implementation can (still) be extended to a complete design which is equivalent to a given full specification.Several algorithms trading off accuracy and computational resources are presented: Starting with a simple 0,1,&KHarX-based simulation, which allows approximate solutions, but is not able to find all errors in the partial implementation, we consider more and more exact methods finally covering all errors detectable in the partial implementation. The exact algorithm reports no error if and only if the current partial implementation conforms to the specification, i.e. it can be extended to a full implementation which is equivalent to the specification.We give a series of experimental results demonstrating the effectiveness and feasibility of the methods presented.
LIDE: a simulation environment for shared virtual memory systems
Authors: S. Petit J. A. Gil J. Sahuquillo A. Pont
Venue: ACM SIGARCH Computer Architecture News (2000)

Shared Virtual Memory (SVM) systems are organizations of Distributed Shared Memory systems (DSM). These systems offer a shared memory programming model that is more intuitive than the message passing paradigm. Other advantages include low hardware and maintenance costs. This paper introduces a new simulation environment for such architectures. The developed tool is an execution-driven simulator aimed at studying the behavior of memory consistency models, with the exception of those needing compiler modifications. Thus, we propose a cheap and flexible way to design efficient consistency approaches for SVM systems.
Covering the computer field
Authors: Gerard Salton
Venue: Communications of the ACM (1967)

During the past year, the Communications has printed approximately twenty papers in each of three main areas: programming language development, compiler management and construction, and numerical methods. In addition, about twenty new algorithms were published, as well as half a dozen papers covering the general area of education in computer science; new proposed standards were also disseminated for various types of paper tape, punched cards, and for data communication codes. Three of the twelve issues were conference issues consisting of papers originally given at the ACM Conference on Programming Languages and Pragmatics, the ACM Symposium on Symbolic and Algebraic Manipulation, and a Symposium on the Impact of Computing on Undergraduate Mathematics. A survey paper was published on simulation languages, and two reports were printed covering the computer scene in Communist China and Europe, respectively.
A formalism for translator interactions
Authors: Jay Earley, Howard Sturgis
Venue: Communications of the ACM (1970)

A formalism is presented for describing the actions of processors for programming languages&mdash;compilers, interpreters, assemblers&mdash;and their interactions in complex systems such as compiler-compilers or extendible languages. The formalism here might be used to define and answer such a question as &ldquo;Can one do bootstrapping using a metacompiler whose metaphase is interpretive?&rdquo; In addition an algorithm is presented for deciding whether or not a given system can be produced from a given set of component processors.
On computing certain elements of the inverse of a sparse matrix
Authors: A. M. Erisman, W. F. Tinney
Venue: Communications of the ACM (1975)

A recursive algorithm for computing the inverse of a matrix from the LU factors based on relationships in Takahashi, et al., is examined. The formulas for the algorithm are given; the dependency relationships are derived; the computational costs are developed; and some general comments on application and stability are made.
An algorithm using symbolic techniques for the Bel-Petrov classification of gravitational fields
Authors: R. A. Harris, J. D. Zund
Venue: Communications of the ACM (1978)

In this note, an algorithm is presented for the symbolic calculation of certain algebraic invariants of the Weyl tensor which permits the determination of the Bel-Petrov types of a gravitational field. This algorithm, although more specialized than that of D'Inverno and Russell-Clark, requires neither the use of a special coordinate system nor the spin coefficient formalism. The algorithm has been implemented in FORMAC and is designed to complete the classification scheme proposed by Petrov in his book. An appendix contains examples illustrating the use of the algorithm.
Highly testable and compact 1-out-of-n code checker with single output
Authors: C. Metra, M. Favalli, B. Ricco
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

This paper presents a novel 1-out-of-n checker that, compared to the other implementations up to now presented, features the advantages of: i) satisfying the TSC or SCD property with respect to all possible internal faults representative of realistic failures; ii) presenting a single output line; iii) requiring significantly lower area overhead.
Routability-driven repeater block planning for interconnect-centric floorplanning
Authors: P. Sarkar, V. Sundararaman, C.-K. Koh
Venue: Proceedings of the 2000 international conference on Computer-aided design (2001)

In this paper, we present a repeater block planning algorithm for interconnect-centric floorplanning. We introduce the concept of independent feasible regions for repeaters and derive an analytical formula for their computation. We develop a routability-driven repeater clustering algorithm to perform repeater block planning based on iterative deletion. The goal is to obtain a high quality solution for the repeater block locations so that performance-driven interconnect synthesis at the routing stage can be carried out with ease, while minimizing the chip area. Experimental results show that our method increases the percentage of all global nets that meet their target delays from 67.5% in [8] to 85%. Meanwhile, our approach is able to minimize the expected routing congestion, making it easier for performance-driven routers to synthesize global nets that require the insertion of repeaters to meet timing constraints.
Exact and approximate estimation for maximum instantaneous current of CMOS circuits
Authors: Y.-M. Jiang, K.-T. Cheng
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

We present an integer-linear-programming-based approach for estimating the maximum instantaneous current through the power supply lines for CMOS circuits. It produces the exact solutions for the maximum instantaneous current for small circuits, and tight upper bounds for large circuits. We formulate the maximum instantaneous current estimation problem as an integer linear programming (ILP) problem, and solve the corresponding ILP formulae to obtain the exact solution. For large circuits we propose to partition the circuits, and apply our ILP-based approach for each sub-circuit. The sum of the exact solutions of all sub-circuits provides an upper bound of the exact solution for the entire circuit. Our experimental results show that the upper bounds produced by our approach combined with the lower bounds produced by a genetic-algorithm-based approach confine the exact solution to a small range.
Applying model-based techniques to the development of UIs for mobile computers
Authors: Jacob Eisenstein, Jean Vanderdonckt, Angel Puerta
Venue: Proceedings of the 6th international conference on Intelligent user interfaces (2001)

Mobile computing poses a series of unique challenges for user interface design and development: user interfaces must now accommodate the capabilities of various access devices and be suitable for different contexts of use, while preserving consistency and usability. We propose a set of techniques that will aid UI designers who are working in the domain of mobile computing. These techniques will allow designers to build UIs across several platforms, while respecting the unique constraints posed by each platform. In addition, these techniques will help designers to recognize and accommodate the unique contexts in which mobile computing occurs. Central to our approach is the development of a user-interface model that serves to isolate those features that are common to the various contexts of use, and to specify how the user-interface should adjust when the context changes. We claim that without some abstract description of the UI, it is likely that the design and the development of user-interfaces for mobile computing will be very time consuming, error-prone or even doomed to failure.