ppxscal/embedding_network huggingface dataset:
Global optimization techniques for automatic parallelization of hybrid applications
Authors: Dhruva R. Chakrabarti, Prithviraj Banerjee
Venue: Proceedings of the 15th international conference on Supercomputing (2001)

This paper presents a novel technique to perform global optimization of communication and preprocessing calls in the presence of array accesses with arbitrary subscripts. Our scheme is presented in the context of automatic parallelization of sequential programs to produce message passing programs for execution on distributed machines. We use the static single assignment (SSA) form for message passing programs as the intermediate representation and then present techniques to perform global optimizations even in the presence of array accesses with arbitrary subscripts. The focus of this paper is in showing that, using a uniform compilation method both at compile-time and at run-time, our framework is able to determine the earliest and the latest legal communication point for a certain distributed array reference even in the presence of arbitrary array addressing functions. Our scheme then heuristically determines the final communication point after considering the interaction between the relevant communication schedules. Owing to combined static and dynamic analysis, a quasi-dynamic method of code generation is implemented. We describe the need for proper interaction between the compiler and the run-time routines for efficient implementation of optimizations as well as for compatible code generation. All of the analyses is initiated at compile-time, static analyses of the program is done as much as possible, and then the run-time routines take over the analyses while building on the data structures initiated at compile time. This scheme has been incorporated in our compiler framework which can use uniform methods to compile, parallelize, and optimize a sequential program irrespective of the subscripts used in array addressing functions. Experimental results for a number of benchmarks on an IBM SP-2 show up to around 10-25% reduction in total run-times in our globally-optimized schemes compared to other state-of-the-art schemes on 16 processors.
Dynamic string searching
Authors: Arne Andersson, Mikkel Thorup
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Optimal bounds are presented for dynamic string searching. If the longest common prefix between a query key x and a currently stored string y is &ell; words, then finding the stored string lexicographically nearest to x takes optimal &THgr;(&radic;log n/log log n + &ell;) time. Similarly, we can insert and delete strings from the stored set within this time bound. The space requirements is linear and the time bounds are worst-case.
A technique for generating almost optimal Floyd-Evans productions for precedence grammars
Authors: J. D. Ichbiah, S. P. Morse
Venue: Communications of the ACM (1970)

A technique is developed for generating almost optimal Floyd-Evans productions given a precedence grammar. A graph formulation is used for the problem of merging productions. The productions generated correspond to the minimum cost inverse-arborescence of that graph. The validity of the technique is demonstrated for weak precedence grammars defined here, but the productions mechanically generated for any precedence grammar can often be modified in such a way that correct, almost optimal parsers are obtained.
Reflections on a candidate design of the user-interface for a wireless vital-signs monitor
Authors: Ben McGarry, Ben Matthews, Margot Brereton
Venue: Proceedings of DARE 2000 on Designing augmented reality environments (2000)

In this paper we present a case study of our candidate design for the user-interface of a wireless vital-signs monitor. We reflect on our design of the user-interface, and relate our design experience to theories of artefact design, evaluating from this case study how the theories apply to the broader design context of design for AR. Theories of `good design' in artefact design literature do not unilaterally apply to the design for an augmented reality device. In many cases, design in AR fields requires the designer to create new cultural conventions by virtue of the fact that the designer is immersing the user in an unfamiliar environment. Thus, the designer is often unable to utilise affordances and existing cultural conventions because the functions and/or use of the object expands the environment in which affordances and cultural conventions currently have meaning.
First-Order System Least Squares For Linear Elasticity: Numerical Results
Authors: Z. Cai, C.-O. Lee, T. A. Manteuffel, S. F. McCormick
Venue: SIAM Journal on Scientific Computing (1999)

Two first-order system least squares (FOSLS) methods based on L2 norms are applied to various boundary value problems of planar linear elasticity. Both use finite element discretization and multigrid solution methods. They are two-stage algorithms that solve first for the displacement flux variable (the gradient of displacement, which easily yields the deformation and stress variables), then for the displacement variable itself. As a complement to a companion theoretical paper, this paper focuses on numerical results, including finite element accuracy and multigrid convergence estimates that confirm uniform optimal performance---even as the material tends to the incompressible limit.
Advanced 3-D Graphics: GNU Maverik--a VR Micro-Kernel
Authors: Adrian West
Venue: Linux Journal (2000)

GNU Maverik system
A real bottom-up operating systems course
Authors: Daniel P. Bovet, Marco Cesati
Venue: ACM SIGOPS Operating Systems Review (2001)

The "Operating Systems" course is included in the Computer Science undergraduate program of almost all universities. It is quite surprising, however, that teachers rarely agree on what should be taught in such courses. Actually, there even isn't a widely agreed definition of what an operating system is.One of the broadest definitions we ever seen has been given in [2]:The operating system is the collection of functions which make available computing services to people who require them.Therefore, the operating system must fill the gap between the computer and the services required by the people using it. However, what kind of services should we consider? Isn't writing a document with a word processor a computing service that people require? And what about playing a strategy game, or browsing the Web?Much more restricted definitions of operating system have been given. For example, in [6] we read:The purpose of an operating system is to provide an environment in which a user can execute programs. The primary goal of an operating system is thus to make the computer system convenient to use. A secondary goal is to use the computer hardware in an efficient manner.Most Operating Systems courses implicitly adopt this definition or a similar one, because it allows teachers to stick to a well-defined set of canonical topics. Actually, two kinds of operating systems courses may co-exist: one addressed to system administrators and one to system programmers. In the first case, the course should teach how to make use of the many existing features inside an OS, how to tune it up properly, and how to set up proper environments for the users. In the second case, the course should explain how the functions are implemented and which are the main issues and trade-offs to be considered while implementing them.In fact, the first kind of course is seldom included in an undergraduate Computer Science program: this is likely due to the fact that operating systems are quite different from each other, thus the experience gathered on one of them, say Sun Microsystem's Solaris, cannot be readily transfered to another one, say IBM's OS/390. We thus concentrate in the rest of this paper on the second type of course, the standard elective fourth year course of an Undergraduate program in Computer Science.
Evaluation of Interest Point Detectors
Authors: Cordelia Schmid, Roger Mohr, Christian Bauckhage
Venue: International Journal of Computer Vision (2000)

Many different low-level feature detectors exist and it is widely agreed that the evaluation of detectors is important. In this paper we introduce two evaluation criteria for interest points' repeatability rate and information content. Repeatability rate evaluates the geometric stability under different transformations. Information content measures the distinctiveness of features. Different interest point detectors are compared using these two criteria. We determine which detector gives the best results and show that it satisfies the criteria well.
Concurrent Exception Handling and Resolution in Distributed Object Systems
Authors: Jie Xu, Alexander Romanovsky, Brian Randell
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

We address the problem of how to handle exceptions in distributed object systems. In a distributed computing environment, exceptions may be raised simultaneously in different processing nodes and thus need to be treated in a coordinated manner. Mishandling concurrent exceptions can lead to catastrophic consequences. We take two kinds of concurrency into account: 1) Several objects are designed collectively and invoked concurrently to achieve a global goal and 2) multiple objects (or object groups) that are designed independently compete for the same system resources. We propose a new distributed algorithm for resolving concurrent exceptions and show that the algorithm works correctly even in complex nested situations, and is an improvement over previous proposals in that it requires only O(nmaxN 2) messages, thereby permitting quicker response to exceptions.
Exploiting Fine-Grained Idle Periods in Networks of Workstations
Authors: Kyung Dong Ryu, Jeffrey K. Hollingsworth
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

Studies have shown that for a significant fraction of the time, workstations are idle. In this paper, we present a new scheduling policy called Linger-Longer that exploits the fine-grained availability of workstations to run sequential and parallel jobs. We present a two-level workload characterization study and use it to simulate a cluster of workstations running our new policy. We compare two variations of our policy to two previous policies: Immediate-Eviction and Pause-and-Migrate. Our study shows that the Linger-Longer policy can improve the throughput of foreign jobs on a cluster by 60 percent with only a 0.5 percent slowdown of local jobs. For parallel computing, we show that the Linger-Longer policy outperforms reconfiguration strategies when the processor utilization by the local process is 20 percent or less in both synthetic bulk synchronous and real data-parallel applications.
Teaching applied computing without programming: a case-based introductory course for general education
Authors: Joe Marks, William Freeman, Henry Leitner
Venue: ACM SIGCSE Bulletin (2001)

We introduce general-education students to key ideas in applied computing through case studies from computer graphics, computer animation, image processing, computer vision, information retrieval, and artificial intelligence. Each case study consists of two lectures: one an intuitive exposition of relevant computer-science concepts, and the other a hands-on introduction to a working system that embodies these concepts. Students use these systems to perform design and problem-solving tasks, thereby reinforcing the abstract concepts presented. Computer programming is neither required nor taught. The course has been offered for two years at the Harvard University Extension School, and has achieved high ratings in student surveys.
Optimally Balanced Spanning Tree of the Star Network
Authors: Adele A. Rescigno
Venue: IEEE Transactions on Computers (2001)

The one-to-all personalized broadcast problem in an interconnection network can be optimally solved with respect to both the time and the number of transmissions if it is possible to construct an optimally balanced spanning tree of the network which is also a shortest path tree. In this paper, we give an algorithm to construct an optimally balanced spanning tree of the star network which is also a shortest path tree. Our result is optimal and improves on [10], [11].
Parametric Amplification of Signals by Noise in Neurons and Neural Networks
Authors: Yu. I. Balkarey, V. O. Nagoutchev, M. G. Evtikhov, M. I. Elinson
Venue: Neural Processing Letters (2000)

The positive role of parametric noise in neural systems is shown. In analogy with transistor effect the weak input signals control the intensive response of nonlinear neurons to parametric noise. As a result gigantic amplification of input signals can be obtained. The mechanism of amplification is simple and robust. It can relate both to biological and artificial neural networks. Such amplification was first investigated in a model of overdamped Kramers oscillator &lsqb;1,2&rsqb;.
Reconstructing a collection of curves with corners and endpoints
Authors: Stefan Funke, Edgar A. Ramos
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

We present an algorithm which provably reconstructs a collection of curves with corners and endpoints from a sample set that satisfies a certain sampling condition. The algorithm outputs a polygonal reconstruction that contains the edges in the correct reconstruction of the curves and such that any additional edge between sample points is justified. Furthermore, we show that for any such collection of curves, there exists a sample set such that a slightly modified version of our algorithm outputs exactly the correct reconstruction. The algorithm also performs quite well in practice.
Why batch and user evaluations do not give the same results
Authors: Andrew H. Turpin, William Hersh
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

Much system-oriented evaluation of information retrieval systems has used the Cranfield approach based upon queries run against test collections in a batch mode. Some researchers have questioned whether this approach can be applied to the real world, but little data exists for or against that assertion. We have studied this question in the context of the TREC Interactive Track. Previous results demonstrated that improved performance as measured by relevance-based metrics in batch studies did not correspond with the results of outcomes based on real user searching tasks. The experiments in this paper analyzed those results to determine why this occurred. Our assessment showed that while the queries entered by real users into systems yielding better results in batch studies gave comparable gains in ranking of relevant documents for those users, they did not translate into better performance on specific tasks. This was most likely due to users being able to adequately find and utilize relevant documents ranked further down the output list.
When your computer needs a lawyer
Authors: John F. Banzhaf,  III
Venue: Communications of the ACM (1968)

Possible liability for negligence, for other torts (such as slander of credit) and for liability under theories of express or implied warranty (guarantees) are discussed, and legal complications are explained, so that users, operators, owners, and leasors of computers may be alerted to potential legal problems. Focus is also on troublespots in contracting for data processing services, in automating record keeping operations, in deciding whether or not to automate certain operations, and in complying with statutes and regulations relating to record keeping. Information is given on patents, copyrights and trade secret protection for programs, and the problem of using copyrighted material in information storage and retrieval systems, including the pending copyright and patent revision bills.
Role of interface manipulation style and scaffolding on cognition and concept learning in learnware
Authors: Kamran Sedig, Maria Klawe, Marvin Westrom
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (2001)

This research investigates the role of interface manipulation style on reflective cognition and concept learning through a comparison of the effectiveness of three verisons of a software application for learning two-dimensional transformation geometry. The three versions respectively utilize a Direct Object Manipulation (DOM) interface in which the user manipulates the visual representation of objects being transformed; a Direct Concept Manipulation (DCM) interface in which the user manipulates the visual representation of the transformation being applied to the object; and a Reflective Direct Concept Manipulation (RDCM) interface in which the DCM approach is extended with scaffolding. Empirical results of a study showed that grade-6 students using the RDCM version learned significantly more than those using the DCM version, who is turn learned significantly more than those using the DOM version. Students using the RDCM version had to process information consciously and think harder than those using the DCM and DOM versions. Despite the relative difficulty when using the RDCM interface style, all three groups expressed a similar (positive) level of liking for the software. This research suggests that some of the educational deficiencies of Direct Manipulation (DM) interfaces are not necessarily caused by their &ldquo;directness,&rdquo; but by what they are directed at&mdash;in this case directness toward objects rather than embedded educational concepts being learned. This paper furthers our understanding of how the DM metaphor can be used in learning- and knowledge-centered software (i.e., learnware) by proposing a new DM metaphor (i.e., DCM), and the incorporation of scaffolding to enhance the DCM approach to promote reflective cognition and deep learning.
Out-of-Vocabulary Rejection based on Selective Attention Model
Authors: Ki-Young Park, Soo-Young Lee
Venue: Neural Processing Letters (2000)

Based on a psychological selective attention theory a new algorithm is developed to provide reliable out-of-vocabulary (OOV) rejection for speech recognition systems in noisy environments. The developed attention model is based on Broadbent's &lsquo;early filtering&rsquo; theory, and the attention adaptation process utilizes a gradient-descent error minimization algorithm with error backpropagation rule. The developed model is applied to isolated-word recognition tasks, and much higher in-vocabulary recognition rates are achieved with the same out-of-vocabulary rejection rates.
An efficient machine-independent procedure for garbage collection in various list structures
Authors: H. Schorr, W. M. Waite
Venue: Communications of the ACM (1967)

A method for returning registers to the free list is an essential part of any list processing system. In this paper, past solutions of the recovery problem are reviewed and compared. A new algorithm is presented which offers significant advantages of speed and storage utilization. The routine for implementing this algorithm can be written in the list language with which it is to be used, thus insuring a degree of machine independence. Finally, the application of the algorithm to a number of different list structures appearing in the literature is indicated.
A general formalation of storage allocation
Authors: A. E. Roberts,  Jr.
Venue: Communications of the ACM (1961)

Formalization of a general computer storage allocation process is attempted. With a given computer M is associated a fictitious computer M&prime; essentially identical to M except in respect to possession of unbounded primary storage. Mappings of the total storage set (internal and external) of M into the direct address set of M&prime; are introduced. A program sequence P for M&prime; is termed M-admissible (relative to a specific execution time period) if there is a mapping under which P and its effective data referents are all located in the direct address set of M. Storage allocation is considered as a process of establishing for an arbitrary M&prime; program a sequence of mappings, a decoupling of the program into M-admissible subprograms and a linking set of interludes. An existence proof in terms of a completely interpretive M program as indicated. Some special cases are discussed. Various restrictions on generality of M&prime; programs are considered under which more practical realization of allocation processes becomes tractable.
High Availability Cluster Checklist
Authors: Tim Burke
Venue: Linux Journal (2000)

With a variety of clustering services on the market, the ability to determine how well options meet your specific business needs is necessary.
On computing functions with uncertainty
Authors: Sanjeev Khanna, Wang-Chiew Tan
Venue: Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2001)

We study the problem of computing a function f(x1,&hellip;, xn) given that the actual values of the variables xi's are known only with some uncertainty. For each variable xi, an interval Ii is known such that the value of xi is guaranteed to fall within this interval. Any such interval can be probed to obtain the actual value of the underlying variable; however, there is a cost associated with each such probe. The goal is to adaptively identify a minimum cost sequence of probes such that regardless of the actual values taken by the unprobed xi's, the value of the function f can be computed to within a specified precision. We design online algorithms for this problem when f is either the selection function or an aggregation function such as sum or average. We consider three natural models of precision and give algorithms for each model. We analyze our algorithms in the framework of competitive analysis and show that our algorithms are asymptotically optimal. Finally, we also study online algorithms for functions that are obtained by composing together selection and aggregation functions.
The camp smalltalk ANSI test suite (poster session)
Authors: Ralph Johnson, Donald MacQueen
Venue: Addendum to the 2000 proceedings of the conference on Object-oriented programming, systems, languages, and applications (Addendum) (2000)

Although there has been an ANSI standard for Smalltalk for some years, there has not been a verification suite for it. This has allowed the various dialects to deviate from the standard without much notice. One of the first Camp Smalltalk projects was a test suite for the ANSI standard protocols. It has several thousand tests based on SUnit, a way of testing protocol conformance, and way of reusing protocol-based tests for each of the concrete classes that is supposed to support a protocol.