ppxscal/embedding_network huggingface dataset:
Algorithm 405: roots of matrix pencils: the generalized eigenvalue problem [F2]
Authors: Alice M. Dell, Roman L. Weil, Gerald L. Thompson
Venue: Communications of the ACM (1971)

* This work was supported by the US National Aeronautics and Space Administration, by the National Science Foundation under Grant GS-2703 to the University of Chicago, and by the US Office of Naval Research under Grant NONR 760(24) NR 047-048 to Carnegie-Mellon University. Computations were done on the University of Chicago's Maniac III computer and were supported by the US Atomic Energy Commission under grants AT (11-1)-614 and AT (11-1)-2094.
Using quantitative information for efficient association rule generation
Authors: B. Pôssas, M. Carvalho, R. Resende, W. Meita,  Jr.
Venue: ACM SIGMOD Record (2000)

The problem of mining association rules in categorical data presented in customer transactions was introduced by Agrawal, Imielinski and Swami [2]. This seminal work gave birth to several investigation efforts [4, 13] resulting in descriptions of how to extend the original concepts and how to increase the performance of the related algorithms.The original problem of mining association rules was formulated as how to find rules of the form set1 rarr; set2. This rule is supposed to denote affinity or correlation among the two sets containing nominal or ordinal data items. More specifically, such an association rule should translate the following meaning: customers that buy the products in set1 also buy the products in set2. Statistical basis is represented in the form of minimum support and confidence measures of these rules with respect to the set of customer transactions.The original problem as proposed by Agrawal et al. [2] was extended in several directions such as adding or replacing the confidence and support by other measures, or filtering the rules during or after generation, or including quantitative attributes. Srikant e Agrawal [16] describe an new approach where quantitative data can be treated as categorical. This is very important since otherwise part of the customer transaction information is discarded. Whenever an extension is proposed it must be checked in terms of its performance. The algorithm efficiency is linked to the size of the database that is amenable to be treated. Therefore it is crucial to have efficient algorithms that enable us to examine and extract valuable decision-making information in the ever larger databases.In this paper we present an algorithm that can be used in the context of several of the extensions provided in the literature but at the same time preserves its performance, as demonstrated in a case study. The approach in our algorithm is to explore multidimensional properties of the data (provided such properties are present), allowing us to combine this additional information in a very efficient pruning phase. This results in a very flexible and efficient algorithm that was used with success in several experiments using categorical and quantitative databases.The paper is organized as follows. In the next section we describe the quantitative association rules and we present an algorithm to generate it. Section 3 presents an optimization of the pruning phase of the Apriori [4] algorithm based on quantitative information associated with the items. Section 4 presents our experimental results for mining four synthetic workloads, followed by some related work in Section 5. Finally we present some conclusions and future work in Section 6.
A polynomial time recognition algorithm for probe interval graphs
Authors: Julie L. Johnson, Jeremy P. Spinrad
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Probe interval graphs were introduced to model a problem arising in a form of DNA sequencing. This paper presents an &Ogr;(n2) algorithm for recognizing probe interval graphs. This is the first polynomial time recognition algorithm for this class.
A New Monolithic Voltage-Controlled Oscillator
Authors: Eric Despain, John Choma,  Jr.
Venue: Analog Integrated Circuits and Signal Processing (2001)

A new monolithic voltage-controlled oscillator exploiting a previously reported monolithic variable capacitance cell is presented. With a 2.3 volt swing in control voltage, the oscillator generates a sinusoidal output signal at frequencies ranging from 55 MHz to 135 MHz. The total harmonic distortion is less than 1%, while frequency slew rate is greater than 16 MHz/ns.
Programming semantics for multiprogrammed computations
Authors: Jack B. Dennis, Earl C. Van Horn
Venue: Communications of the ACM (1966)

The semantics are defined for a number of meta-instructions which perform operations essential to the writing of programs in multiprogrammed computer systems. These meta-instructions relate to parallel processing, protecting of separate computations, program debugging, and the sharing among users of memory segments and other computing objects, the names of which are hierarchically structured. The language sophistication contemplated is midway between an assembly language and an advanced algebraic language.
A comparison of tree-balancing algorithms
Authors: J.-L. Baer, B. Schwab
Venue: Communications of the ACM (1977)

Several algorithms &mdash; height-balance (i.e. AVL and extensions), weight-balance (i.e. BB and WB), and total restructuring &mdash; for building balanced binary search trees are compared. The criteria for comparison encompass theoretical aspects (e.g. path lengths) and implementation independent and machine/algorithm-dependent measures (e.g. run time). A detailed analysis of code is also presented at a level believed to be language- and compiler-independent. The quality of the resulting trees and the overhead spent on building them are analyzed, and some guidelines are given for an efficient use of the methods. If insertion and subsequent queries are the only operations of interest, then &ldquo;pure&rdquo; AVL trees present the overall best qualities.
Streaming Media
Authors: Frank LaMonica
Venue: Linux Journal (2001)

LaMonica describes the hardware and software technology used on the server side of the streaming process.
New LISP techniques for a paging environment
Authors: Arnold Rochfeld
Venue: Communications of the ACM (1971)

The system described herein employs the block concept, and that of global and local variables, in addition to the methods applied in most LISP systems. Also, a new means of list representation is used: &ldquo;local sequential&rdquo; for lists created during compilation, and &ldquo;block level sequential&rdquo; for those created dynamically. A new garbage collection algorithm has been introduced to make lists as compact as possible; partial garbage collection is performed after each block exit instead of total garbage collection when storage is exhausted. The algorithm does not use the customary flagging procedure. This combination of features has eliminated the need for a free list, and effectively minimizes the number of pages used at any moment.
Optimal test access architectures for system-on-a-chip
Authors: Krishnendu Chakrabarty
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2001)

Test access is a major problem for core-based system-on-a-chip (SOC) designs. Since embedded cores in an SOC are not directly accessible via chip inputs and outputs, special access mechanisms are required to test them at the system level. An efficient test access architecture should also reduce test cost by minimizing test application time. We address several issues related to the design of optimal test access architectures that minimize testing time., including the assignment of cores to test buses, distribution of test data width between multiple test buses, and analysis of test data width required to satisfy an upper bound on the testing time. Even though the decision versions of all these problems are shown to be NP-complete, they can be solved exactly for practical instances using integer linear programming (ILP). As a case study, the ILP models for two hypothetical but nontrivial systems are solved using a public-domain ILP software package.
Programming pearls: Writing correct programs
Authors: Jon Bentley
Venue: Communications of the ACM (1983)

In the late 1960s people were talking about the promise of programs that verify the correctness of other programs. Unfortunately, it is now the middle of the 1980s, and, with precious few exceptions, there is still little more than talk about automated verification systems. Despite unrealized expectations, however, the research on program verification has given us something far more valuable than a black box that gobbles programs and flashes &ldquo;good&rdquo; or &ldquo;bad&rdquo;&mdash;we now have a fundamental understanding of computer programming. The purpose of this column is to show how that fundamental understanding can help programmers write correct programs. But before we get to the subject itself, we must keep it in perspective. Coding skill is just one small part of writing correct programs. The majority of the task is the subject of the three previous columns: problem definition, algorithm design, and data structure selection. If you perform those tasks well, then writing correct code is usually easy.
How to bypass the Wassenaar arrangement: a new application for watermarking
Authors: Franck Leprévost, Raphaël Erard, Touradj Ebrahimi
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

The scope of this article is to clarify the current legal and political situation related to electronic surveillance on the one hand, and to export regulations for encryption software on the other hand. We will look at different international agreements, such as the UKUSA agreement and the Wassenaar arrangement, and elaborate on current encryption techniques falling under these regulations. This discussion is then followed by introducing the basic concepts of steganography and digital watermarking which could be used for secret communication. As a consequence, we propose an original way to legally bypass the international export regulations using these technologies. To this end a new watermarking technique is proposed, which is robust to JPEG2000 compression and provides a good channel capacity. The efficiency of the proposed technique is analyzed by means of simulations to allow for secure communications.
An algorithm to determine mutually exclusive operations in behavioral descriptions
Authors: J. Li, R. K. Gupta
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

Scheduling and binding are two major tasks in architectural synthesis from behavioral descriptions. The information about the mutually exclusive pairs of operations is very useful in reducing both the total delay of the schedule and the resource usage in the final circuit implementation. In this paper, we present an algorithm to identify the largest set of mutually exclusive operation pairs in behavioral descriptions. Our algorithm uses data-flow analysis on a tabular model of system functionality, and is shown to work better than the existing methods for identifying mutually exclusive operations.Interconnect Tuning Strategies for High-Performance Ics83590471abs.htm _Andrew B. Kahng, Sudhakar Muddu, Egino Sarto and Rahul SharmaSilicon Graphics, Inc.Interconnect tuning is an increasingly critical degree of freedom in the physical design of high-performance VLSI systems. By interconnect tuning, we refer to the selection of line thicknesses, widths and spacings in multi-layer interconnect to simultaneously optimize signal distribution, signal performance, signal integrity, and interconnect manufacturability and reliability. This is a key activity in most leading-edge design projects, but has received little attention in the literature. Our work provides the first technology-specific studies of interconnect tuning in the literature. We center on global wiring layers and interconnect tuning issues related to bus routing, repeater insertion, and choice of shielding/spacing rules for signal integrity and performance. We ad-dress four basic questions. (1) How should width and spacing be allocated to maximize performance for a given line pitch? (2) For a given line pitch, what criteria affect the optimal interval at which repeaters should be inserted into global interconnects? (3) Under what circumstances are shield wires the optimum technique for improving interconnect performance? (4) In global interconnect with repeaters, what other interconnect tuning is possible? Our study of question (4) demonstrates a new approach of offsetting repeater placements that can reduce worst-case cross-chip delays by over 30% in current technologies.
Memory-efficient interconnect optimization
Authors: Minghorng Lai, D. F. Wong
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

Interconnect design has emerged as one of the major challenges facing chip designers as VLSI manufacturing progresses and gate sizes scale down. Dynamic programming(DP) is an efficient and robust technique for finding optimal solutions to interconnect optimization problems in VLSI design. However, DP's huge memory requirement often limits its effectiveness and sometimes, due to limited storage resources, even makes it impossible to solve a problem of practical size. Since interconnect optimization is often a subprocess embedded in an upper level design procedure, a memory and time efficient implementation of DP can be very favorable to circuit designers. In this paper, we develop a new memory-efficient dynamic programming approach to interconnect optimization problems. Our method utilizes selective storage and recomputation technique. This memory and time efficient algorithm speeds up the dynamic programming method without compromising solution quality. Experiments show tremendous saving, both in storage and time, over traditional dynamic programming algorithms. Our novel approach can also be generalized for other VLSI applications using DP algorithms.
Dynamic skin triangulation
Authors: Ho-Lun Cheng, Tamal K. Dey, Herbert Edelsbrunner, John Sullivan
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

This paper describes an algorithm for maintaining an approximating triangulation of a deforming surface in R3. The triangulation adapts dynamically to changing shape, curvature, and topology of the surface.
Incremental deployment of a router-assisted reliable multicast scheme
Authors: Christos Papadopoulos, Emmanouil Laliotis
Venue: Proceedings of NGC 2000 on Networked group communication (2000)

Recently, several schemes have been proposed that address the problem of scalable reliable multicast using router assistance. These include LMS, PGM, AIM and OTERS, among others. While these schemes (arguably) achieve significantly better performance than non-assisted schemes, a thorny issue remains: are these schemes incrementally deployable? More specifically, what is the performance impact of partial deployment to the application and the network? What is the best strategy to deploy such schemes? These questions, while very important, have not been addressed yet. In this paper we investigate the performance of Light-weight Multicast Services (LMS) under various deployment strategies. Our results are preliminary, mostly due to lack of established strategies for incremental deployment of such services. First, we propose a method to incrementally deploy LMS which has minimal impact on router processing and state. Then, we investigate the performance of LMS for various basic deployment strategies, including random, core, stub, and border router deployment, and for different topologies, including random and transit-stub topologies. We also examine node v.s. path deployment. Our evaluation is carried out using the ns simulator and topologies generated with GT-ITM. Our results show that there are significant differences among the various deployment strategies with random being the worst. Finally, we discuss our observations in the context of other router-assisted schemes and identify common issues.
Recognizing Action Units for Facial Expression Analysis
Authors: Ying-li Tian, Takeo Kanade, Jeffrey F. Cohn
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2001)

Most automatic expression analysis systems attempt to recognize a small set of prototypic expressions, such as happiness, anger, surprise, and fear. Such prototypic expressions, however, occur rather infrequently. Human emotions and intentions are more often communicated by changes in one or a few discrete facial features. In this paper, we develop an Automatic Face Analysis (AFA) system to analyze facial expressions based on both permanent facial features (brows, eyes, mouth) and transient facial features (deepening of facial furrows) in a nearly frontal-view face image sequence. The AFA system recognizes fine-grained changes in facial expression into action units (AUs) of the Facial Action Coding System (FACS), instead of a few prototypic expressions. Multistate face and facial component models are proposed for tracking and modeling the various facial features, including lips, eyes, brows, cheeks, and furrows. During tracking, detailed parametric descriptions of the facial features are extracted. With these parameters as the inputs, a group of action units (neutral expression, six upper face AUs and 10 lower face AUs) are recognized whether they occur alone or in combinations. The system has achieved average recognition rates of 96.4 percent (95.4 percent if neutral expressions are excluded) for upper face AUs and 96.7 percent (95.6 percent with neutral expressions excluded) for lower face AUs. The generalizability of the system has been tested by using independent image databases collected and FACS-coded for ground-truth by different research teams.
An optimal method for deletion in one-sided height-balanced trees
Authors: S. H. Zweben, M. A. McDonald
Venue: Communications of the ACM (1978)

A one-sided height-balanced tree is a binary tree in which every node's right subtree has a height which is equal to or exactly one greater than the height of its left subtree. It has an advantage over the more general AVL tree in that only one bit of balancing information is required (two bits are required for the AVL tree). It is shown that deletion of an arbitrary node of such a tree can be accomplished in O(log n) operations, where n is the number of nodes in the tree. Moreover the method is optimal in the sense that its complexity cannot be reduced in order of magnitude. This result, coupled with earlier results by Hirschberg, indicates that, of the three basic problems of insertion, deletion, and retrieval, only insertion is adversely affected by this modification of an AVL tree.
ACM president's letter: eating our seed corn
Authors: Peter J. Denning
Venue: Communications of the ACM (1981)

On July 12 and 13, 1980, the biennial meeting of Computer Science Department chairmen was held at Snowbird, Utah. This meeting, which is organized by the Computer Science Board (CSB), is a forum for the heads of the 83 departments in the United States and Canada that grant Ph.D.s in Computer Science. The meeting was attended by 56 department heads or their representatives, and by six observers from industry and government. This report was developed during the meeting as a result of intensive discussions about the crisis in Computer Science. This report was endorsed by the entire assembly.
Explorations: structured labs for first-time programmers
Authors: Ray Lischner
Venue: ACM SIGCSE Bulletin (2001)

A style of homework assignment is presented, called explorations. An exploration is part of an introductory programming course, specifically designed to help first-time programmers overcome common hurdles, such as misconceptions about the nature of computers and programs. An exploration is a structured lab where the student makes predictions about a program's behavior, then runs the program to compare the actual result with the predicted result. The questions are deliberately designed to challenge common errors and preconceived notions of computers and programming languages. Guided questions help the students refine their mental models of computers. Successful explorations have resulted in significant gains in comprehension, retention, and student satisfaction. Several guidelines are presented to help teachers write effective explorations.
An innovative design and studio-based CS degree
Authors: Michael Docherty, Peter Sutton, Margot Brereton, Simon Kaplan
Venue: ACM SIGCSE Bulletin (2001)

The University of Queensland has recently established a new design-focused, studio-based computer science degree. The Bachelor of Information Environments degree augments the core courses from the University's standard CS degree with a stream of design courses and integrative studio-based projects undertaken every semester. The studio projects integrate and reinforce learning by requiring students to apply the knowledge and skills gained in other courses to open-ended real-world design projects. The studio model is based on the architectural studio and involves teamwork, collaborative learning, interactive problem solving, presentations and peer review. This paper describes the degree program, its curriculum and rationale, and reports on experiences in the first year of delivery.
Characteristics of the FORTRAN CEP language
Authors: O. G. Mancino
Venue: Communications of the ACM (1964)

The FORTRAN CEP languages differs from FORTRAN II mainly because: (1) it extends the variety of the modes for real quantities; (2) it allows suitable mixtures, in an input/output list or in an expression, of quantities that occur under different modes; (3) it makes it possible to address a greater number of input/output equipment; and (4) it removes the restrictions on the complexity of the list of quantities to be transmitted between the magnetic core memory and the drum or the magnetic tape units.
Subtyping arithmetical types
Authors: Joseph (Yossi) Gil
Venue: ACM SIGPLAN Notices (2001)

We consider the type system formed by a finite set of primitive types such as integer, character, real, etc., and three type construction operators: (i) Cartesian product, (ii) disjoint sum, and (iii) recursive type definitions. Type equivalence is defined to obey the arithmetical rules: commutativity and associativity of product and sum and distributivity of product over sum. We offer a compact representation of the types in this system as multivariate algebraic functions. This type system admits two natural notions of subtyping: "multiplicative", which roughly corresponds to the notion of object-oriented subtyping, and "additive", which seems to be more appropriate in our context. Both kinds of subtyping can be efficiently computed if no recursive definitions are allowed. Our main result is that additive subtyping is undecidable in the general case. Perhaps surprisingly, this undecidability result is by reduction from Hilbert's Tenth Problem (HIO): the solution of Diophantine equations.