ppxscal/embedding_network huggingface dataset:
Syntax-directed least-errors analysis for context-free languages: a practical approach
Authors: Gordon Lyon
Venue: Communications of the ACM (1974)

A least-errors recognizer is developed informally using the well-known recognizer of Earley, along with elements of Bellman's dynamic programming. The analyzer takes a general class of context-free grammars as drivers, and any finite string as input. Recognition consists of a least-errors count for a corrected version of the input relative to the driver grammar. The algorithm design emphasizes practical aspects which help in programming it.
Increased capacity through hierarchical cellular structures with inter-layer reuse in an enhanced GSM radio network
Authors: Jürgen Deissner, Gerhard P. Fettweis
Venue: Mobile Networks and Applications (2001)

In today's cellular networks it becomes harder to provide the resources for the increasing and fluctuating traffic demand exactly in the place and at the time where and when they are needed. Moreover, frequency planning for a hierarchical cellular network, especially to cover indoor areas and hot-spots, is a complicated and expensive task. Therefore, we study the ability of hierarchical cellular structures with inter-layer resuse to increase the capacity of a GSM (Global System for Mobile Communications) radio network by applying Total Frequency Hopping (T-FH) and Adaptive Frequency Allocation (AFA) as a strategy to reuse the macro- and microcell resources without frequency planning in indoor picocells. The presented interface analysis indicates a considerable interference reduction gain by T-FH in conjunction with AFA, which can be used for carrying an additional indoor traffic of more than 300 Erlang/km2, i.e., increasing the spectral capacity by over 50%, namely 33 Erlang/km2/MHz. From these results we draw a number of general conclusions for the design of hierarchical cellular structures in future mobile radio networks. For example, we may conclude that they require reuse strategies that not only adapt to the current local interference situation, but additionally distribute the remaining interference to as many resources as possible. For a hierarchical GSM network this requirement is fulfilled by the T-FH/AFA technique very well.
Empirical Bayesian Motion Segmentation
Authors: Nuno Vasconcelos, Andrew Lippman
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2001)

We introduce an empirical Bayesian procedure for the simultaneous segmentation of an observed motion field and estimation of the hyperparameters of a Markov random field prior. The new approach exhibits the Bayesian appeal of incorporating prior beliefs, but requires only a qualitative description of the prior, avoiding the requirement for a quantitative specification of its parameters. This eliminates the need for trial-and-error strategies for the determination of these parameters and leads to better segmentations.
Some approaches to best-match file searching
Authors: W. A. Burkhard, R. M. Keller
Venue: Communications of the ACM (1973)

The problem of searching the set of keys in a file to find a key which is closest to a given query key is discussed. After &ldquo;closest,&rdquo; in terms of a metric on the the key space, is suitably defined, three file structures are presented together with their corresponding search algorithms, which are intended to reduce the number of comparisons required to achieve the desired result. These methods are derived using certain inequalities satisfied by metrics and by graph-theoretic concepts. Some empirical results are presented which compare the efficiency of the methods.
Computer-aided system integration for data-intensive multimedia applications (poster session)
Authors: Sami J. Habib, Alice C. Parker
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

In this paper we describe a computer-aided design (CAD) tool for automatically designing and integrating network and data management hardware for data-intensive multimedia applications, such as the animation film studio. The tool determines the network strategy, interconnection hardware required, number and location of proxies and servers, and file allocation.
A method for incrementally compiling languages with nested statement structure
Authors: Jay Earley, Paul Caizergues
Venue: Communications of the ACM (1972)

A method of incremental compilation is presented which applies especially to programming languages in which statements can be nested (such as Algol and PL/I). The method permits editing of the source language using a general purpose text editor, and incremental processing of changes without frequent recompilation of entire routines. The essential points of the method are: (1) the syntax of the language is restricted insofar as which constructs may occur on lines; (2) an internal data structure (called the skeleton) is maintained to represent the statement structure; (3) the recompilation is partially batched in the sense that recompilation of modified lines does not occur until the last of a set of editing commands has been received; and (4) the parsing and compilation are factored into two parts, that done on individual lines and that done globally to handle the relationships between the lines.
Panel: The next generation of acess control models (panel session): do we need them and what should they be?
Authors: Ravi Sandhu, Elisa Bertino, Jaeger Jaeger, Richard Kuhn, Carl Landwehr
Venue: Proceedings of the sixth ACM symposium on Access control models and technologies (2001)

Research on access control models was started in the 1960s and 1970s by the two thrusts of mandatory and discretionary access control. Mandatory access control (MAC) came from the military and national security arenas whereas discretionary access control (DAC) had its roots in academic and commercial research laboratories. These two thrusts were dominant through the 1970s and 1980s almost to exclusion of any other approach to access control models. In the 1990s we have seen a dramatic shift towards pragmatism. The dominant access-control model of the 1990s is role-based access control (RBAC). It is now understood that RBAC encompasses MAC and DAC as special cases and goes beyond them in providing a policy-neutral framework. This SACMAT meeting has evolved from a highly successful and productive series of ACM workshops on RBAC. This panel will address the basic question of where do we go next with access control models. Do we need additional models or can we simply evolve the current set of RBAC models? Is RBAC fundamentally deficient in some way? Where should be go in terms of standards? Is there useful formal and theoretical work to be done in the access control models arena? The first meeting with the title SACMAT is a fitting place to address these questions.
Building secure knowledge bases: combining Java agents and DBagents
Authors: Edgar Weippl
Venue: Proceedings of the fifth international conference on Autonomous agents (2001)

Today, databases are ubiquitous. In factories machine tools are connected to databases that process outstanding orders and log occurring errors. Our industrial partner AMS engineering builds and maintains machine tools for various client companies that operate worldwide. AMS goal is to create a data warehouse that helps them analyzing machine failures and quickly launching response by reusing knowledge applied at one of their clients sites. Agents that roam through these databases are an efficient way of gathering the required information. As all operations heavily rely on database transactions, we propose to implement agents that are executed within a database management system. A Java- based agent environment allows encapsulating the database agents in Java agents to securely transmit them. Having arrived at the clients computer, the Java agent unpacks the database agent that performs the required tasks.
Handling of Irregularities in Human Centered Systems: A Unified Framework for Data and Processes
Authors: Takahiro Murata, Alex Borgida
Venue: IEEE Transactions on Software Engineering (2000)

Practical process-support and workflow systems should be built to describe the simple, normal flow of events and then deal easily with irregularities, including tolerating deviations. Similarly, these systems should describe the normal format and constraints concerning the large amounts of data that are usually stored, but then deal with abnormalities and possibly accommodate exceptional values. We offer a framework for treating both kinds of irregularities uniformly by using the notion of exception handling (with human agents as potential online exception handlers) and applying it to processes that have been reified as objects in classes with steps as attributes. As a result, only a small number of new constructs, which can be applied orthogonally, need to be introduced. Special run-time checks are used to deal with the consequences of permitting deviations from the norm to persist as violations of constraints. A logical semantics of process coordination and deviations is presented as a specification for implementations.
A generic model for reflective design
Authors: Panagiotis Louridas, Pericles Loucopoulos
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (2000)

Rapid technological change has had an impact on the nature of software. This has led to new exigencies and to demands for software engineering paradigms that pay particular atttention to meeting them. We advocate that such demands can be met, at least in large parts, through the adoption of software engineering processes that are founded on a reflective stance. To this end, we turn our attention to the field of Design Rationale. We analyze and characterize Design Rationale approaches and show that despite surface differences between different approaches, they all tend to be variants of a relatively small set of static and dynamic affinities. We use the synthesis of static and dynamic affinities to develop a generic model for reflective design. The model is nonprescriptive and affects minimally the design process. It is context-independent and is intended to be used as a facilitator in participative design, supporting group communication and deliberation. The potential utility of the model is demonstrated through two examples, one from the world of business design and the other from programming language design
A virtual memory system for picture processing
Authors: Ben Tsutom Wada
Venue: Communications of the ACM (1984)

A virtual memory system designed specifically for picture processing, Raster Handler 2 provides programs with efficient access to pixels. It features square partition of images, imbalanced allocation of frames, and nondemand page replacement. RH2 is implemented in software and incorporates a prepaging algorithm designed specifically for picture processing.
An experimental laboratory for pattern recognition and signal processing
Authors: N. M. Herbst, P. M. Will
Venue: Communications of the ACM (1972)

An interactive computer-controlled scanning and display system has been in operation at the IBM Thomas J. Watson Research Center for three years. The system includes two flying-spot scanners and a TV camera specially interfaced to a process control digital computer, dot-mode and vector displays, analog input and output facilities, and a variety of other experimental equipment. The system design and programming support are described and typical applications in scanner control, optical character recognition, and image processing are presented.
A note on approximating ex
Authors: S. Lubkin
Venue: Communications of the ACM (1960)

In reference to the discussion about evaluation ex on page 500 of the September Communications of the ACM, may I point out that there is no need to use Mr. Berin's lengthy expressions to obtain relation (9). If we use the simple formula (5) for x/2 and divide by the same formula for - x/2, we get (9) immediately. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
A programming system for the on-line analysis of biomedical images
Authors: Louis Hodes
Venue: Communications of the ACM (1970)

A preliminary description of the software for a computer-display system is given with special emphasis on the man-machine interaction. This system is intended for a wide variety of biomedical applications. As an example, the methods are applied to the karyotyping of chromosomes. The system is separated into four programming tasks: picture transformations, file maintenance, picture structuring, and display management. Picture structuring is considered as the vehicle for man-machine communication. A prototype data format for pictures, called a picture-form, is developed. Structure operators are defined which manipulate picture-forms to produce new picture-forms. Many of the ideas are taken from the symbolic mathematical laboratory at MIT conceived by Marvin Minsky.
Remark on algorithm 343 [F2]
Authors: Herbert Niessner
Venue: Communications of the ACM (1972)

We had at our disposal a double precision version (all real variables are declared to be of type double precision) for the IBM 360/50 of the algorithm 343 [1] with logical IF statements converted to arithmetical ones. In the following three modifications which we found to be of practical value are to be discussed.
The do-all problem in broadcast networks
Authors: Bogdan S. Chlebus, Dariusz R. Kowalski, Andrzej Lingas
Venue: Proceedings of the twentieth annual ACM symposium on Principles of distributed computing (2001)

The problem of performing t tasks in a distributed system on p failure-prone processors is one of the fundamental problems in distributed computing. If the tasks are similar and independent and the processors communicate by sending messages then the problem is called Do-All. In our work the communication is over a multiple-access channel, and the attached stations may fail by crashing. The measure of performance is work, defined as the number of the available processor steps. Algorithms are required to be reliable in that they perform all the tasks as long as at least one station remains operational. We show that each reliable algorithm always needs to perform at least the minimum amount &OHgr;(t + p&radic;t) of work. We develop an optimal deterministic algorithm for the channel with collision detection performing only the minimum work &THgr;(t + p&radic;t). Another algorithm is given for the channel without collision detection, it performs work O(t + p&radic;t + p &middot; min {f, t}), where f < p is the number of failures. It is proved to be optimal if the number of faults is the only restriction on the adversary. Finally we consider the question if randomization helps for the channel without collision detection against weaker adversaries. We develop a randomized algorithm which needs to perform only the expected minimum work if the adversary may fail a constant fraction of stations, but it has to select the failure-prone stations prior to the start of an algorithm.
A note on information organization and storage
Authors: J. C. Huang
Venue: Communications of the ACM (1973)

Since the logical structure of a data base can be represented by a tree or graph, it is quite natural for us to view the process of designing a data base as that of constructing a tree or a graph. A general method for constructing such a tree or graph is provided. There are three important elements in this general construction method; namely, a set of binary relations, an algorithm for constructing subsets of a set, and an algorithm for selecting an element from the given set of objects. The use of different relations and algorithms results in different information structures, as list, tree, ring, etc. Thus the problem of information organization and storage is reduced to that of defining relations and formulating algorithms under a given set of constraints. The results presented may be valuable to designers as useful design concepts, and may serve as a basis for developing a formal theory on the subject.
Teaching software tools via design patterns
Authors: Yonglei Tao
Venue: Proceedings of the Australasian conference on Computing education (2000)

Commercial software tools are increasingly used for teaching computer science courses. Because they are powerful and complex, they are often difficult to learn and to use. It is critical to balance benefits and problems that a software tool may bring about. Visual C++ is used as a tool for developing GUI applications in our &ldquo;GUI Design&rdquo; course. We identified examples of several well-known design patterns with Visual C++ and based our lecture on these patterns when teaching the tool. Our experience shows that design patterns help deal with the complex and flatten the learning curve without diverting too much attentions from the course's primary objectives.
Transient-free working-set statistics
Authors: M. C. Easton, B. T. Bennett
Venue: Communications of the ACM (1977)

Transient-free average working-set size and transient-free missing-page rate for a finite sample of a reference string are defined. Use of these statistics is appropriate if the contents of the working set at the start of the recorded string are unknown. If a certain stationarity condition holds, these statistics provide unbiased estimates of expected working-set sizes, missing-page probabilities, and interreference distance probabilities. Two other pairs of estimators are shown to be biased. Expressions for the transient-free statistics are obtained in terms of interval statistics. Several methods of computation are discussed, the usefulness of each depending on length of the sample, number of distinct references, and the amount of main storage available to the computer performing the calculations. In particular, methods are described for handling long strings containing many distinct page names.
Reading of electronic documents: the usability of linear, fisheye, and overview+detail interfaces
Authors: Kasper Hornbæk, Erik Frøkjær
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2001)

Reading of electronic documents is becoming increasingly important as more information is disseminated electronically. We present an experiment that compares the usability of a linear, a fisheye, and an overview+detail interface for electronic documents. Using these interfaces, 20 subjects wrote essays and answered questions about scientific documents. Essays written using the overview+detail interface received higher grades, while subjects using the fisheye interface read documents faster. However, subjects used more time to answer questions with the overview+detail interface. All but one subject preferred the overview+detail interface. The most common interface in practical use, the linear interface, is found to be inferior to the fisheye and overview+detail interfaces regarding most aspects of usability. We recommend using overview+detail interfaces for electronic documents, while fisheye interfaces mainly should be considered for time-critical tasks.
General performance analysis of key-to-address transformation methods using an abstract file concept
Authors: V. Y. Lum
Venue: Communications of the ACM (1973)

This paper presents a new approach to the analysis of performance of the various key-to-address transformation methods. In this approach the keys in a file are assumed to have been selected from the key space according to a certain probabilistic selection algorithm. All files with the same number of keys selected from this key space will be suitably weighted in accordance with the algorithm, and the average performance of the transformation methods on these files will be used as the potential of these methods. Using this analysis, methods with the same overall performance can be classified and key distributions partial to certain transformations can be identified. All this can be done analytically. The approach is applied to a group of transformation methods using files whose keys are selected randomly.
A slicing-based approach for locating type errors
Authors: F. Tip, T. B. Dinesh
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (2001)

The effectiveness of a type-checking tool strongly depends on the accuracy of the positional information that is associated with type errors. We present an approach where the location associated with an error message e is defined as a slice Pe of the program P being type-checked. We show that this approach yields highly accurate positional information: Pe is a program that contains precisely those program constructs in P that caused error e. Semantically, we have the interesting property that type-checking Pe is guaranteed to produce the same error e. Our approach is completely language-independent and has been implemented for a significant subset of Pascal. We also report on experiments with object-oriented type systems, and with a subset of ML.
&ldquo;Women in programming&rdquo; is not an oxymoron!
Authors: Cindy Meyer Hanchey
Venue: Proceedings of the seventh annual consortium for computing in small colleges central plains conference on The journal of computing in small colleges (2001)

In teaching the Comparative Programming Languages course, one quickly discovers that there are few references in most of the texts to women who have made significant contributions to the field. As we become more aware of the emphasis on recruiting and retaining young women in the computing field, we as educators must take an active part in providing role models&mdash;both to the young women and to the men who will become the professionals in the field. This paper addresses one mechanism that has been classroom tested.
Undergraduate research in genetic algorithms
Authors: Linda Bright Lankewicsz
Venue: ACM SIGCSE Bulletin (2001)

The study of genetic algorithms (GAs) in the undergraduate curriculum introduces students to parallel search strategies and to experimental design. Not only does it build on the topics covered in an Analysis of Algorithms course but it exposes students to issues such as the importance of the form of representation to solving a problem and to the difficulties encountered when a local minima is selected as the solution rather than the best global solution. As an illustration of the merits of including genetic algorithms in the curriculum, an undergraduate research project investigating the use of a diploid sexual model for crossover operations is described.
Correlation method of circuit-performance and technology fluctuations for improved design reliability
Authors: D. Miyawaki, S. Matsumoto, H. J. Mattausch, S. Ooshiro, M. Suetake, M. Miura-Mattausch, S. Kumashiro, T. Yamaguchi, K. Yamashita, N. Nakayama
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

We propose a method of correlating circuit performance with technology fluctuations during the circuit-design phase. The method employs test circuits sensitive for technology fluctuations and a circuit simulation model which enables to interpret the correlation. We validate our proposal with a cascode-current-source test circuit and the drift-diffusion MOSFET model HiSIM. The chosen test circuit allows to separate intra-chip and inter-chip technology fluctuations and to correlate these fluctuations with circuit-performance fluctuating. One important result is that intra-chip fluctuations increase faster than inter-chip fluctuations with decreasing gate length. Quantitative modeling with HiSIM reveals random fluctuation of the effective gate length as the most likely origin for these findings.