ppxscal/embedding_network huggingface dataset:
Generic ideals and Moreno-Soc&iacute;as conjucture
Authors: Edith Aguirre, Abdul Salam Jarrah, Reinhard Laubenbacher
Venue: Proceedings of the 2001 international symposium on Symbolic and algebraic computation (2001)

Let f1,&hellip;,fn be homogeneous polynomials generating a generic ideal I in the ring of polynomials in n variables over an infinite field. Moreno-Soc&iacute;as conjectured that for the graded reverse lexicographic term ordering, the initial ideal in(I) is a weakly reverse lexicographic ideal. This paper contains a new proof of Moreno-Soc&iacute;as' conjecture for the case n = 2.
OOF: an image-based finite-element analysis of material microstructures
Authors: Stephen A. Langer, Edwin R. Fuller,  Jr., W. Craig Carter
Venue: Computing in Science and Engineering (2001)

Determining a material's macroscopic properties given its microscopic structure is of fundamental importance to materials science. The authors describe two public-domain programs that jointly predict macroscopic behavior. The programs start from an image of the microstructure and end with results from finite-element calculations.
The TWA reservation system
Authors: David Gifford, Alfred Spector
Venue: Communications of the ACM (1984)

Where can you find a solid, forthright overview of the computer systems and management behind airline reservations? NASA's space shuttle? Or any of the multitude of other large computer systems that support important projects or national activities? It's hard, sometimes impossible: partly because the people who worked on such systems often do not have the time to write about their experiences: and partly because many professional journalists who interview these people do not have the technical background to ferret out answers to the fundamental design questions addressed in these systems.
A unifying approach to scheduling
Authors: Manfred Ruschitzka, R. S. Fabry
Venue: Communications of the ACM (1977)

This paper presents a scheme for classifying scheduling algorithms based on an abstract model of a scheduling system which formalizes the notion of priority. Various classes of scheduling algorithms are defined and related to existing algorithms. A criterion for the implementation efficiency of an algorithm is developed and results in the definition of time-invariant algorithms, which include most of the commonly implemented ones. For time-invariant algorithms, the dependence of processing rates on priorities is derived. The abstract model provides a framework for implementing flexible schedulers in real operating systems. The policy-driven scheduler of Bernstein and Sharp is discussed as an example of
Architectural and application: the performance of the NEC SX-4 on the NCAR benchmark suite
Authors: Steven W. Hammond, Richard D. Loft, Philip D. Tannenbaum
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

In November 1994, the NEC Corporation announced the SX-4 supercomputer. It is the third in the SX series of supercomputers and is upward compatible from the SX-3R vector processor with enhancements for scalar processing, short vector processing, and parallel processing. In this paper we describe the architecture of the SX-4 which has an 8.0 ns clock cycle and a peak performance of 2 Gflops per processor. We also describe the composition of the NCAR Benchmark Suite, designed to evaluate the computers for use on climate modeling applications. Additionally, we contrast this benchmark suite with other benchmarks. Finally, we detail the scalability and performance of the SX-4/32 relative to the NCAR Benchmark Suite.
Verifying safety properties of concurrent Java programs using 3-valued logic
Authors: Eran Yahav
Venue: ACM SIGPLAN Notices (2001)

We provide a parametric framework for verifying safety properties of concurrent Java programs. The framework combines thread-scheduling information with information about the shape of the heap. This leads to error-detection algorithms that are more precise than existing techniques. The framework also provides the most precise shape-analysis algorithm for concurrent programs. In contrast to existing verification techniques, we do not put a bound on the number of allocated objects. The framework even produces interesting results when analyzing Java programs with an unbounded number of threads. The framework is applied to successfully verify the following properties of a concurrent program: bull;Concurrent manipulation of linked-list based ADT preserves the ADT datatype invariant [19]. bull;The program does not perform inconsistent updates due to interference. bull;The program does not reach a deadlock. bull;The program does not produce run-time errors due to illegal thread interactions. We also find bugs in erroneous versions of such implementations. A prototype of our framework has been implemented.
Operational compatability of systems&mdash;conventions
Authors: George F. Ryckman
Venue: Communications of the ACM (1961)

This project is engaged in (a) a program of research into the application of the concepts and techniques of modern data processing to the design of mechanical parts, and (b) the further development of automatic programming systems for numerically controlled machine tools. The project is a cooperative venture between the Computer Applications Group of the Electronic Systems Laboratory and the Design and Graphics Division of the Mechanical Engineering Department, and is sponsored by the Manufacturing Methods Division of the USAF Air Material Command through Contract AF-33(600)-40604.
Quality of service in multimedia digital libraries
Authors: Elisa Bertino, Ahmed K. Elmagarmid, Mohand-Saïd Hacid
Venue: ACM SIGMOD Record (2001)

There is currently considerable interest in developing multimedia digital libraries. However, it has become clear that existing architectures for management systems do not support the particular requirements of continuous media types. This is particularly the case in the important area of quality of service support. In this correspondence, we discuss quality of service issues within digital libraries and present a reference architecture able to support some quality aspects.
Editorial
Authors: Jessica Hodgins
Venue: ACM Transactions on Graphics (TOG) (2000)

I'm very pleased to have the opportunity to take over as editor-in-chief after Holly Rushmeier's strong leadership of the past three years. ACM has made a big effort to get TOG back on schedule after the delays caused by changing to a new publication system. With this issue, we are almost on schedule again and the backlog of accepted papers is significantly reduced. I hope to further shorten the time the return reviews to authors and to get accepted paper to readers. As part of that effort, I have asked Steve Fortune for Bell Labs, John Hart from Washington State, Joe Marks from MERL, and Jorg Peters from the University of Florida to be new members of the editorial board to replace those who retired with the end of Holly's term.I expect that we'll see significant changes in the role of journals during my three-year term. Right now, journals utilize peer reviews and a revision cycle to provide accreditation to research, but this process is tied to a particular distribution medium and requires financial support in the form of subscription fees. With the increasing use of web-baed publishing, I expect that the accreditation and distribution functions will begin to separate. Accreditation will continue to play an important role in scientific reputations and academic careers, while the publication media will become far more diverse. This diversification is particularly important for graphics because many of its important results are not represented well on paper. TOG has moved in this direction with a web page that is expertly maintained by Eric Haines and contains occasional supplemental material (http://www.acm.org./tog/). If TOG is to represent the true breadth of graphics, however, we will have to make much more of an effort in this direction.During the next three years, we will almost certainly see significant changes in graphics as well. Clearly, the field is expanding beyond the creation of beautiful and useful images and image sequences. New emphases include increasingly realistic physical modeling, interactive worlds, and nonvisual modalities. Graphics is a fascinating field, in part because researchers are able to adopt and adapt new ideas from so many other fields: art, vision, physics, materials science, control, optimization and biomechanics. I look forward to the innovative and creative work that the community will submit to TOG during the next three years.
Estimating file access time of floppy disks
Authors: M. A. Pechura, J. D. Schoeffler
Venue: Communications of the ACM (1983)

Small computers often use floppy disks for storage. Since such disks are significantly slower than hard disks, the response time of a given application program is due predominantly to the time required to access data in files. Access time is dependent on three factors: hardware (disk drive and interface), the operating system in use, and the patterns of file access of application programs. A simple-to-use method of predicting access times with good accuracy is presented. The method makes use of simple calibration experiments that provide information related to the hardware and operating system characteristics of the system in use. This is combined with patterns of file access information for a given application program to predict access time for that program. Actual examples for several small computer systems are presented.
Type-indexed rows
Authors: Mark Shields, Erik Meijer
Venue: ACM SIGPLAN Notices (2001)

Record calculi use labels to distinguish between the elements of products and sums. This paper presents a novel variation, type-indexed rows, in which labels are discarded and elements are indexed by their type alone. The calculus, lambda;TIR, can express tuples, recursive datatypes, monomorphic records, polymorphic extensible records, and closed-world style type-based overloading. Our motivating application of lambda;TIR, however, is to encode the "choice" types of XML, and the "unordered tuple" types of SGML. Indeed, lambda;TIR is the kernel of the language XM lambda;, a lazy functional language with direct support for XML types ("DTDs") and terms ("documents").The system is built from rows, equality constraints, insertion constraints and constrained, or qualified, parametric polymorphism. The test for constraint satisfaction is complete, and for constraint entailment is only mildly incomplete. We present a type checking algorithm, and show how lambda;TIR may be implemented by a type-directed translation which replaces type-indexing by conventional natural-number indexing. Though not presented in this paper, we have also developed a constraint simplification algorithm and type inference system.
Fast and flexible string matching by combining bit-parallelism and suffix automata
Authors: Gonzalo Navarro, Mathieu Raffinot
Venue: Journal of Experimental Algorithmics (JEA) (2000)

The most important features of a string matching algorithm are its efficiency and its flexibility. Efficiency has traditionally received more attention, while flexibility in the search pattern is becoming a more and more important issue. Most classical string matching algorithms are aimed at quickly finding an exact pattern in a text, being Knuth-Morris-Pratt (KMP) and the Boyer-Moore (BM) family the most famous ones. A recent development uses deterministic "suffix automata" to design new optimal string matching algorithms, e.g. BDM and TurboBDM. Flexibility has been addressed quite separately by the use of "bit-parallelism", which simulates automata in their nondeterministic form by using bits and exploiting the intrinsic parallelism inside the computer word, e.g. the Shift-Or algorithm. Those algorithms are extended to handle classes of characters and errors in the pattern and/or in the text, their drawback being their inability to skip text characters. In this paper we merge bit-parallelism and suffix automata, so that a nondeterministic suffix automaton is simulated using bit-parallelism. The resulting algorithm, called BNDM, obtains the best from both worlds. It is much simpler to implement than BDM and nearly as simple as Shift-Or. It inherits from Shift-Or the ability to handle flexible patterns and from BDM the ability to skip characters. BNDM is 30%-40% faster than BDM and up to 7 times faster than Shift-Or. When compared to the fastest existing algorithms on exact patterns (which belong to the BM family), BNDM is from 20% slower to 3 times faster, depending on the alphabet size. With respect to flexible pattern searching, BNDM is by far the fastest technique to deal with classes of characters and is competitive to search allowing errors. In particular, BNDM seems very adequate for computational biology applications, since it is the fastest algorithm to search on DNA sequences and flexible searching is an important problem in that area. As a theoretical development related to flexible pattern matching, we introduce a new automaton to recognize suffixes of patterns with classes of characters. To the best of our knowledge, this automaton has not been studied before.
Compact list representation: definition, garbage collection, and system implementation
Authors: Wilfred J. Hansen
Venue: Communications of the ACM (1969)

Compact lists are stored sequentially in memory, rather than chained with pointers. Since this is not always convenient, the Swym system permits a list to be chained, compact, or any combination of the two. A description is given of that list representation and the operators implemented (most are similar to those of LISP 1.5). The system garbage collector attempts to make all lists compact; it relocates and rearranges all of list storage using temporary storage. This unique list-compacting garbage collection algorithm is presented in detail. Several classes of the macros used to implement the system are described. Finally, consideration is given to those design factors essential to the success of a plex processing system implementation.
On Broadcast Disk Paging
Authors: Sanjeev Khanna, Vincenzo Liberatore
Venue: SIAM Journal on Computing (2000)

Broadcast disks are an emerging paradigm for massive data dissemination. In a broadcast disk, data is divided into n equal-sized pages, and pages are broadcast in a round-robin fashion by a server. Broadcast disks are effective because many clients can simultaneously retrieve any transmitted data. Paging is used by the clients to improve performance, much as in virtual memory systems. However, paging on broadcast disks differs from virtual memory paging in at least two fundamental aspects: A page fault in the broadcast disk model has a variable cost that depends on the requested page as well as the current state of the broadcast. Prefetching is both natural and a provably essential mechanism for achieving significantly better competitive ratios in broadcast disk paging. In this paper, we design a deterministic algorithm that uses prefetching to achieve an O(n log k) competitive ratio for the broadcast disk paging problem, where k denotes the size of the client's cache. We also show a matching lower bound of $\Omega(n\log k)$ that applies even when the adversary is not allowed to use prefetching. In contrast, we show that when prefetching is not allowed, no deterministic online algorithm can achieve a competitive ratio better than $\Omega(nk)$. Moreover, we show a lower bound of $\Omega(n \log k)$ on the competitive ratio achievable by any nonprefetching randomized algorithm against an oblivious adversary. These lower bounds are trivially matched from above by known results about deterministic and randomized marking algorithms for paging. An interpretation of our results is that in the broadcast disk paging, prefetching is a perfect substitute for randomization.
Non-stop Haskell
Authors: A. M. Cheadle, A. J. Field, S. Marlow, S. L. Peyton Jones, R. L. While
Venue: Proceedings of the fifth ACM SIGPLAN international conference on Functional programming (2000)

We describe an efficient technique for incorporating Baker's incremental garbage collection algorithm into the Spineless Tagless G-machine on stock hardware. This algorithm eliminates the stop/go execution associated with bulk copying collection algorithms, allowing the system to place an upper bound on the pauses due to garbage collection. The technique exploits the fact that objects are always accessed by jumping to code rather than being explicitly dereferenced. It works by modifying the entry code-pointer when an object is in the transient state of being evacuated but not scavenged. An attempt to enter it from the mutator causes the object to "self-scavenge" transparently before resetting its entry code pointer. We describe an implementation of the scheme in v4.01 of the Glasgow Haskell Compiler and report performance results obtained by executing a range of applications. These experiments show that the read barrier can be implemented in dynamic dispatching systems such as the STG-machine with very short mutator pause times and with negligible overhead on execution time.
Educationally critical aspects of a deep understanding of the concept of an information system
Authors: Chris Cope
Venue: Proceedings of the Australasian conference on Computing education (2000)

This study identified and compared a deep understanding of the concept of an information system (IS) with the various levels of understanding of a group of undergraduate IS students. The aim was to identify aspects of the concept of an IS that were educationally critical to that development of a deep understanding. The study was significant in that the educationally critical aspects of the concept of an IS have not been researched previously. Yet, without addressing these aspects in teaching and learning the development of a deep understanding is unlikely. The nature of a deep understanding of the concept of an IS was established from the literature. For effective practice, an IS should be conceptualised as a social system supported by embedded information technology. A group of undergraduate students were interviewed and completed questionnaires about their understanding of the concept of an IS before, during and after a year of study. The student data was analysed using phenomenographic research techniques. Six qualitatively different levels of understanding of the concept of an IS were described. The students' levels of understanding were found to differ from the desired understanding with respect to a number of educationally critical aspects. These differences involved both social and technical aspects of an IS and the relationship between the social and technical aspects. The identification of the educationally critical aspects of the concept of an IS was significant in that learning tasks can now be designed which enhance students' likelihood of developing an appropriate understanding.
Algorithm 489: the algorithm SELECT&mdash;for finding the ith smallest of n elements [M1]
Authors: Robert W. Floyd, Ronald L. Rivest
Venue: Communications of the ACM (1975)

SELECT will rearrange the values of array segment X[L: R] so that X[K] (for some given K; L &le; K &le; R) will contain the (K-L+1)-th smallest value, L &le; I &le; K will imply X[I] &le; X[K], and K &le; I &le; R will imply X[I] &ge; X[K. While SELECT is thus functionally equivalent to Hoare's algorithm FIND [1], it is significantly faster on the average due to the effective use of sampling to determine the element T about which to partition X. The average time over 25 trials required by SELECT and FIND to determine the median of n elements was found experimentally to be: n 500 1000 5000 10000 SELECT 89 ms. 141 ms. 493 ms. 877 ms. FIND 104 ms. 197 ms. 1029 ms. 1964 ms. The arbitrary constants 600, .5, and .5 appearing in the algorithm minimize execution time on the particular machine used. SELECT has been shown to run in time asymptotically proportional to N + min (I, N-I), where N = L - R + 1 and I = K - L + 1. A lower bound on the running time within 9 percent of this value has also been proved [2]. Sites [3] has proved SELECT terminates.
An overview of the proposed american national standard for local distributed data interfaces
Authors: William E. Burr
Venue: Communications of the ACM (1983)

The Local Distributed Data Interface (LDDI) Project of X3 Technical Committee X3T9 has resulted in three draft proposed American National Standards for a high performance local area network. The proposed standards are organized in accordance with the ISO Reference Model for Open Systems Interconnection and encompass the lowest two protocol layers (data link and physical) of the model, plus a serial broadband coaxial bus interface. The intended application of the LDDI is as a backend network for the interconnection of high performance CPUs and block transfer peripherals such as magnetic disk and tapes. A carrier-sense multiple access with collision prevention (CSMA-CP) distributed bus arbitration protocol is employed. The cable interface supports the attachment of up to 28 ports over a cable distance of 0.5 km (8 ports may be attached to a 1 km cable) at a transfer rate of 50 Mbit/s.
The role and challenges of computational chemistry in industrial problems
Authors: Siddharth Dasgupta
Venue: Computing in Science and Engineering (2000)

To remain competitive, the US chemical industry needs to use all available tools to increase productivity. Computational chemistry can help design new materials and improve manufacturing efficiency. However, it needs to focus on method development at all length and time scales. This article illustrates the challenges and opportunities with two specific examples of industrial problems.
A Bayesian Computer Vision System for Modeling Human Interactions
Authors: Nuria M. Oliver, Barbara Rosario, Alex P. Pentland
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

We describe a real-time computer vision and machine learning system for modeling and recognizing human behaviors in a visual surveillance task [1]. The system is particularly concerned with detecting when interactions between people occur and classifying the type of interaction. Examples of interesting interaction behaviors include following another person, altering one's path to meet another, and so forth. Our system combines top-down with bottom-up information in a closed feedback loop, with both components employing a statistical Bayesian approach [2]. We propose and compare two different state-based learning architectures, namely, HMMs and CHMMs for modeling behaviors and interactions. The CHMM model is shown to work much more efficiently and accurately. Finally, to deal with the problem of limited training data, a synthetic ¿Alife-style¿ training system is used to develop flexible prior models for recognizing human interactions. We demonstrate the ability to use these a priori models to accurately classify real human behaviors and interactions with no additional tuning or training.
Online digital computer measurement of a neurological control system
Authors: L. Stark, R. Payne, Y. Okabe
Venue: Communications of the ACM (1962)

Quantative measurements of the neurological control system for hand movement have shown results both of diagnostic value and of theoretical interest in understanding the underlying neural mechanisms and their system organization [1-4]. The requirement for dynamic analysis for a complex unpredictable input is necessary in order to distinguish between behavior attributable to the &ldquo;neurological&rdquo; system and that due to the powerful brain prediction apparatus. In order to meet this need, reduce the hidden errors in analyzing filtered data, permit shorter experiments (and thus less dependence upon assumptions of time invariance) and eliminate painstaking pencil-and-ruler analysis, we have inaugurated an online digital computer system for this and related experiments. The RW-300 computer is a magnetic-drum (8000 18-bit words), solid-state computer that is often used in process control applications.1 It has integral analog-to-digital and digital-to-analog conversion facilities.