ppxscal/embedding_network huggingface dataset:
IT skills portfolio research in SIGCPR proceedings: analysis, synthesis and proposals
Authors: Makoto Nakayama, Norma G. Sutcliffe
Venue: Proceedings of the 2001 ACM SIGCPR conference on Computer personnel research (2001)

This paper provides an analysis on information technology (IT) skills portfolio issues from the perspective of firms. The motivation behind this study was our observation that firms are having increasing difficulty in determining their optimal skills portfolio and in acquiring and managing that portfolio in turbulent times. Because a shortage of skilled IT professionals with has been a common theme from the early days of computing, we believe that an analysis of past work using the skills portfolio perspective gives us insights into the gaps where future IS research can illuminate this area. First, the paper reviews 102 IT skills portfolio related papers that appeared in the SIGCPR proceedings between 1985 and 2000. Then the thesis of these papers are summarized and classified according to what skills portfolio firms look for and how they acquire and maintain skills. Particular attention is paid to the gaps in the research to date. Finally, a set of research issues and propositions are given based on the analysis.
An approximate method for generating asymmetric random variables
Authors: John S. Ramberg, Bruce W. Schmeiser
Venue: Communications of the ACM (1974)

Tukey's lambda distribution is generalized to provide an algorithm for generating values of unimodal asymmetric random variables. This algorithm has the same advantages as the symmetric random variable generator previously given by the authors, except that the addition of another parameter complicates the problem of finding the parameter values to fit a distribution.
Internal and tape sorting using the replacement-selection technique
Authors: Martin A. Goetz
Venue: Communications of the ACM (1963)

A general technique for sequencing unsorted records is presented. The technique is shown to be applicable for the first stage of a generalized sort program (the formation of initial strings) as well as for sorting records within a memory storage (an internal sort). It is shown that given N records in memory storage, records are sequenced using 1+log2 N tests per record, that initial string lengths will average 2N for random input records, and that reading, writing and processing can be accomplished simultaneously if the computer permits such overlap.
Computers and employment
Authors: A. Borodin, C. C. Gotlieb
Venue: Communications of the ACM (1972)

The relationship of computers and automation to employment is part of the more general relation of technological change to employment. The most obvious effect is that increases in productivity due to technology can eliminate jobs. Technology affects the individual worker, in the nature and amount of his work, and in his attitudes toward that work. Technological change affects the occupational structure of the entire labor force. Because of the central importance of these effects, the impact of technology has been the subject of extensive study by economists, sociologists, political scientists, and psychologists. Even within a single discipline, studies are often contradictory, and conclusions are colored by political overtones. We wish to delineate some of the issues, and present arguments given to support different viewpoints.
An optimal procedure for gap closing in whole genome shotgun sequencing
Authors: Richard Beigel, Noga Alon, Simon Kasif, Mehmet Serkan Apaydin, Lance Fortnow
Venue: Proceedings of the fifth annual international conference on Computational biology (2001)

Tettelin et. al. proposed a new method for closing the gaps in whole genome shotgun sequencing projects. The method uses a multiplex PCR strategy in order to minimize the time and effort required to sequence the DNA in the missing gaps. This procedure has been used in a number of microbial sequencing projects including Streptococcus pneumoniae and other bacteria. In this paper we describe a theoretical framework for this problem and propose an improved method that guarantees to minimize the number of steps involved in the gap closure procedures. In given particular collection of n/2 DNA fragments we describe a strategy that requires. 0.75 log n work in eight parallel rounds of experiment closely matching a corresponding lower bound 0.5 log of n
A terminology proposal
Authors: Fred Gruenberger
Venue: Communications of the ACM (1960)

It has been suggested that we need some new words in our industry. For example, consider the following two definitions of the term random access: Access to storage under conditions in which the next position from which information is to be obtained is in no way dependent on the previous one. Feature of certain internal memory systems, particularly magnetic drum type. (In both cases the italics are the author's.) of a set of publication standards suitable for use by the Association for Computing Machinery, based on the standards adopted by the Machine Computation Committee of the American Institute of Chemical Engineers. The writer, as a member of this Committee, is acting merely as agent of the Committee in presenting the following upon the request of the Editor for Standards of the ACM. This article is only a summary of the standards adopted by the AIChE; further details are contained in a pamphlet entitled &ldquo;Guide to Abstracts and Manuals for Computer Program Interchange&rdquo;, prepared by the Machine Computation Committee of the American Institute of Chemical Engineers.1
IBM 704 code-nundrums
Authors: Murray Grumette
Venue: Communications of the ACM (1958)

These CODE-NUNDRUMS are 704 coding puzzles, each of which contains an amusing twist. They are of the same category as chess end-problems, which often present artificial positions unlikely ever to be encountered in actual play, but the study of which undeniably sharpens one's performance in real games. So these puzzles, by pointing up the potentialities of the computing machine, should benefit the programmer who admittedly will never be called upon to &ldquo;replace the contents of the AC with K, without using the letter A.&rdquo; 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
Stability Radius and Internal Versus External Stability in Banach Spaces: An Evolution Semigroup Approach
Authors: Stephen Clark, Yuri Latushkin, Stephen Montgomery-Smith, Timothy Randolph
Venue: SIAM Journal on Control and Optimization (2000)

In this paper the theory of evolution semigroups is developed and used to provide a framework to study the stability of general linear control systems. These include autonomous and nonautonomous systems modeled with unbounded state-space operators acting on Banach spaces. This approach allows one to apply the classical theory of strongly continuous semigroups to time-varying systems. In particular, the complex stability radius may be expressed explicitly in terms of the generator of an (evolution) semigroup. Examples are given to show that classical formulas for the stability radius of an autonomous Hilbert-space system fail in more general settings. Upper and lower bounds on the stability radius are proven for Banach-space systems. In addition, it is shown that the theory of evolution semigroups allows for a straightforward operator-theoretic analysis of internal stability as determined by classical frequency-domain and input-output operators, even for nonautonomous Banach-space systems. In particular, for the nonautonomous setting, internal stability is shown to be equivalent to input-output stability for stabilizable and detectable systems. For the autonomous setting, an explicit formula for the norm of input-output operator is given.
Contemporary software development environments
Authors: William E. Howden
Venue: Communications of the ACM (1982)

There are a wide variety of software development tools and methods currently available or which could be built using current research and technology. These tools and methods can be organized into four software development environments, ranging in complexity from a simple environment containing few automated tools or expensive methods to a complete one including many automated tools and built around a software engineering database. The environments were designed by considering the life-cycle products generated during two classes of software development projects. Relative cost figures for the environments are offered and related issues, such as standardization, effectiveness, and impact, then addressed.
Generic summaries for indexing in information retrieval
Authors: Tetsuya Sakai, Karen Sparck-Jones
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

This paper examines the use of generic summaries for indexing in information retrieval. Our main observations are that: (1) With or without pseudo-relevance feedback, a summary index may be as effective as the corresponding fulltext index forprecision-oriented search of highly relevant documents. %43 But a reasonably sophisticated summarizer, using a compression ratio of 10-30%, is desirable for this purpose. (2) In pseudo-relevance feedback, using a summary index at initial search and a fulltext index at final search is possibly effective for precision-oriented search, regardless of relevance levels. This strategy is significantly more effective than the one using the summary index only and probably more effective than using summaries as mere term selection filters. %the use of summaries as mere term selection filters. %The summary quality is probably not a critical factor for this strategy, For this strategy, the summary quality is probably not a critical factor, and a compression ratio of 5-10% appears best.
The algorithm sequential access method: an alternative to index sequential
Authors: Jerry D. Whitt, A. Gale Sullenberger
Venue: Communications of the ACM (1975)

A requirement of many computer file processing systems is the ability to access data stored on a direct access storage device (DASD) both sequentially and randomly. A popular method which provides both types of access is the index sequential organization. The purpose of this study is to propose and analyze a file organization method which should be appropriate for the same type of environment as index sequential but would be more efficient at the two types of access. This proposed method is designated the Algorithm Sequential Access Method (ASAM).
Designing and Optimizing a Scalable CORBA Notification Service
Authors: Pradeep Gore, Ron Cytron, Douglas Schmidt, Carlos O'Ryan
Venue: Proceedings of the ACM SIGPLAN workshop on Languages, compilers and tools for embedded systems (2001)

Many distributed applications require a scalable event-driven communication model that decouples suppliers from consumers and simultaneously supports advanced quality of service (QoS) properties and event filtering mechanisms. The CORBA Notification Service provides a publish/subscribe mechanism that is designed to support scalable event-driven communication by routing events efficiently between many suppliers and consumers, enforcing various QoS properties (such as reliability, priority, ordering, and timeliness), and filtering events at multiple points in a distributed system.This paper provides several contributions to research on scalable notification services. First, we present the CORBA Notification Service architecture and illustrate how it addresses limitations with the earlier CORBA Event Service. Second, we explain how we addressed key design challenges faced when implementing the Notification Service in TAO, which is our high-performance, real-time ORB. We discuss the optimizations used to improve the scalability of TAO's Notification Service. Finally, we present empirical results of the performance of our implementation.
Fast distributed graph coloring with O(&Dgr;) colors
Authors: Gianluca De Marco, Andrzej Pelc
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

We consider the problem of deterministic distributed coloring of an n-vertex graph with maximum degree &Dgr;, assuming that every vertex knows a priori only its own label and parameters n and &Dgr;. The aim is to get a fast algorithm using few colors. Linial [17] showed a vertex-coloring algorithm working in time &Ogr;(log* n) and using &Ogr;(&Dgr;2 colors. We improve both the time and the number of colors simultaneously by showing an algorithm working in time &Ogr;(log*(n/&Dgr;)) and using &Ogr;(&Dgr;) colors. This is the first known &Ogr;(&Dgr;)-vertex-coloring distributed algorithm which can work faster than in polylogarithmic time. Our method also gives an edge-coloring algorithm with the number of colors and time as above. On the other hand, it follows from Linial [17] that our time of &Ogr;(&Dgr;)-coloring cannot be improved in general. In addition we show how our method gives fast coloring algorithms in communication models weaker than Linial's.
An improved algorithm for decentralized extrema-finding in circular configurations of processes
Authors: Ernest Chang, Rosemary Roberts
Venue: Communications of the ACM (1979)

This note presents an improvement to LeLann's algorithm for finding the largest (or smallest) of a set of uniquely numbered processes arranged in a circle, in which no central controller exists and the number of processes is not known a priori. This decentralized algorithm uses a technique of selective message extinction in order to achieve an average number of message passes of order (n log n) rather than O(n2).
Randomizing combinatorial algorithms for linear programming when the dimension is moderately high
Authors: M. Pellegrini
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

In the last decade researchers in computational geometry have produced a series of algorithms for linear programming, based on a randomized combinatorial approach, which are tuned for linear programs where the number of variables d is small compared to the number n of constraints, although not so small to be considered a constant of the problem. One natural question is how practical are these algorithms for classes of LP instances not necessarily derived from problems in computational geometry. In this paper, building within the randomized combinatorial approach, we propose two algorithms for linear programming and we give evidence of their empirical running times on several classes of randomly generated instances. Comparisons with state of the art free software (lp-solve) and state of the art commercial software (Cplex) lead to the conclusion that the randomized combinatorial approach for systems with n &ap; d, at the present state of our research, can be competitive for dense systems and for sparse systems where a large fraction of the constraints are equalities. We also consider the case of dense systems where n > > d, which is typical in instances from computational geometry problems, for which we improve upon recent results of G&auml;tner and Sch&ouml;nherr [13].
A compositional approach to statecharts semantics
Authors: Gerald Lüttgen, Michael von der Beeck, Rance Cleaveland
Venue: ACM SIGSOFT Software Engineering Notes (2000)

Statecharts is a visual language for specifying reactive system behavior. The formalism extends traditional finite-state machines with notions of hierarchy and concurrency, and it is used in many popular software design notations. A large part of the appeal of Statecharts derives from its basis in state machines, with their intuitive operational interpretation. The classical semantics of Statecharts, however, suffers from a serious defect; it is not compositional, meaning that the behavior of system descriptions cannot be inferred from the behavior of their subsystems. Compositionality is a prerequisite for exploiting the modular structure of Statecharts for simulation, verification, and code generation, and it also provides the necessary foundation for reusability. This paper suggests a new compositional approach to formalizing Statecharts semantics as flattened labeled transition systems in which transitions represent system steps. The approach builds on ideas developed for timed process calculi and employs structural operational rules to define the transitions of a Statecharts expression in terms of the transitions of its subexpressions. It is first presented for a simple dialect of Statecharts, with respect to a variant of Pnueli and Shalev's semantics, and is illustrated by means of a small example. To demonstrate its flexibility, the proposed approach is then extended to deal with practically useful features available in many Statecharts variants, namely state references, history states, and priority concepts along state hierarchies.
Signing electronic contracts
Authors: David Molnar
Venue: Crossroads (2000)

Electronic commerce faces the problem of signing electronic contracts. Three approaches for handling electronic contracts include 1) no trusted third party protocols, 2) strongly-trusted third party protocols and 3) weakly-trusted third party protocols. A secondary problem facing electronic commerce is self-enforcing contract design.
OMPI: optimizing MPI programs using partial evaluation
Authors: Hirotaka Ogawa, Satoshi Matsuoka
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

MPI is gaining acceptance as a standard for message-passing in high-performance computing, due to its powerful and flexible support of various communication styles. However, the complexity of its API poses significant software overhead, and as a result, applicability of MPI has been restricted to rather regular, coarse-grained computations. Our OMPI (Optimizing MPI) system removes much of the excess overhead by employing partial evaluation techniques, which exploit static information of MPI calls. Because partial evaluation alone is insufficient, we also utilize template functions for further optimization. To validate the effectiveness for our OMPI system, we performed baseline as well as more extensive benchmarks on a set of application cores with different communication characteristics, on the 64-node Fujitsu AP1000 MPP. Benchmarks show that OMPI improves execution efficiency by as much as factor of two for communication-intensive application core with minimal code increase. It also performs significantly better than previous dynamic optimization technique.
GIT&mdash;a heuristic program for testing pairs of directed line graphs for isomorphism
Authors: Stephen H. Unger
Venue: Communications of the ACM (1964)

Given a pair of directed line graphs, the problem of ascertaining whether or not they are isomorphic is one for which no efficient algorithmic solution is known. Since a straightforward enumerative algorithm might require 40 years of running time on a very high speed computer in order to compare two 15-node graphs, a more sophisticated approach seems called for. The situation is similar to that prevailing in areas such as game-playing and theorem-proving, where practical algorithms are unknown (for the interesting cases), but where various practical though only partially successful techniques are available. GIT&mdash;Graph Isomorphism Tester&mdash;incorporates a variety of processes that attempt to narrow down the search for an isomorphism, or to demonstrate that none exists. No one scheme is relied upon exclusively for a solution, and the program is designed to avoid excessive computation along fruitless lines. GIT has been written in the COMIT language and successfully tested on the IBM 7090.
An empirical study of regression test selection techniques
Authors: Todd L. Graves, Mary Jean Harrold, Jung-Min Kim, Adam Porter, Gregg Rothermel
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (2001)

Regression testing is the process of validating modified software to detect whether new errors have been introduced into previously tested code and to provide confidence that modifications are correct. Since regression testing is an expensive process, researchers have proposed regression test selection techniques as a way to reduce some of this expense. These techniques attempt to reduce costs by selecting and running only a subset of the test cases in a program's existing test suite. Although there have been some analytical and empirical evaluations of individual techniques, to our knowledge only one comparative study, focusing on one aspect of two of these techniques, has been reported in the literature. We conducted an experiment to examine the relative costs and benefits of several regression test selection techniques. The experiment examined five techniques for reusing test cases, focusing on their relative ablilities to reduce regression testing effort and uncover faults in modified programs. Our results highlight several differences between the techiques, and expose essential trade-offs that should be considered when choosing a technique for practical application.
Starving philosophers: experimentation with monitor synchronization
Authors: Steven Robbins
Venue: ACM SIGCSE Bulletin (2001)

Textbook discussions of synchronization seldom go beyond a brief introduction in terms of classical problems. This paper presents a simulator for the monitor solution of the dining philosophers problem that students can use to experimentally explore how such a solution might behave in practice. The simulator, which can be run remotely from a browser or can be downloaded for running locally, is written in Java so that it can be run on almost any system.
The Maximum Factor Queue Length Batching Scheme for Video-on-Demand Systems
Authors: Charu C. Aggarwal, Joel L. Wolf, Philip S. Yu
Venue: IEEE Transactions on Computers (2001)

In a video-on-demand environment, batching of video requests is often used to reduce I/O demand and improve throughput. Since viewers may defect if they experience long waits, a good video scheduling policy needs to consider not only the batch size but also the viewer defection probabilities and wait times. Two conventional scheduling policies for batching are the first-come-first-served (FCFS) policy, which schedules the video with the longest waiting request, and the maximum queue length (MQL) policy, which selects the video with the maximum number of waiting requests. Neither of these policies leads to entirely satisfactory results. MQL tends to be too aggressive in scheduling popular videos by considering only the queue length to maximize batch size, while FCFS has the opposite effect by completely ignoring the queue length and focusing on arrival time to reduce defections. In this paper, we introduce the notion of factored queue length and propose a batching policy that schedules the video with the maximum factored queue length. We refer to this as the MFQL policy. The factored queue length is obtained by weighting each video queue length with a factor which is biased against the more popular videos. An optimization problem is formulated to solve for the best weighting factors for the various videos. We also consider MFQL implementation issues. A simulation is developed to compare the proposed MFQL variants with FCFS and MQL. Our study shows that MFQL yields excellent empirical results in terms of standard performance measures such as average latency time, defection rates, and fairness.
Theory of answering queries using views
Authors: Alon Y. Halevy
Venue: ACM SIGMOD Record (2000)

The problem of answering queries using views is to find efficient methods of answering a query using a set of previously materialized views over the database, rather than accessing the database relations. The problem has recently received significant attention because of its relevance to a wide variety of data management problems, such as query optimization, the maintenance of physical data independence, data integration and data warehousing. This article surveys the theoretical issues concerning the problem of answering queries using views.