Barbara Simons

Barbara Simons
IBM · Theory (retired)

Ph.D., Computer Science

About

80
Publications
9,968
Reads
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1,881
Citations
Citations since 2016
0 Research Items
283 Citations
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20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060

Publications

Publications (80)
Conference Paper
Properly designed and engineered computerized voting systems can facilitate voting and increase the security and reliability of our voting systems. Unfortunately, in their eagerness to have the most modern and best election equipment and to take advantage of almost $4 billion in federal funding, well meaning election officials were quick to accept...
Article
Full-text available
Properly designed and engineered computerized voting systems can facilitate voting and increase the security and reliability of our voting systems. Unfortunately, in their eagerness to have the most modern and best election equipment and to take advantage of almost $4 billion in federal funding, well meaning election officials were quick to accept...
Chapter
Full-text available
We present two tests for analyzing deadlock for a class of communicating sequential processes. The tests can be used for deadlock detection in parallel and distributed programs at compile time, or for debugging purposes at run time. They can also be used in conjunction with an algorithm we have for constructing valid execution traces for this class...
Article
Having been assigned part-time to an administrative position (concurrently with normal academic duties) in charge of curriculum management, the author has developed curriculorum, a system to assist in that task that was, is, and will continue ...
Conference Paper
As a result of Florida 2000, some Americans concluded that paper ballots simply couldn’t be counted, even though businesses, banks, racetracks, lottery systems, and others count and deal with paper all the time. Instead, paperless computerized voting systems (Direct Recording Electronic or DREs) were touted as the solution to “the Florida problem”....
Article
The risks of using inappropriate, careless or poorly designed software to the general public, the press and policymakers are discussed. The analogies are needed to help people gain insight into the complexity of large problems to counter unrealistic claims about the safety or robustness of software. There is a software that attempts to interpret pa...
Article
Full-text available
The denial of service (DoS) attacks which pose risk to an internet based voting system, SERVE (secure electronic registration and voting experiment) system, is discussed. The privacy of SERVE ballots is protected using encryption during transmission over the internet and it is decrypted at the central server. While the Gore/Nader swapping depended...
Article
As a result of the Florida 2000 election fiasco, some people concluded that paper ballots simply couldn’t be counted. Instead, paperless computerized voting systems were touted as the solution to “the Florida problem.” Replacing hanging chads with 21st century technology, proponents claimed, would result in accurate election counts and machines tha...
Article
Full-text available
Is it true that politics and technology don't mix?
Chapter
Copyright is an area that until recently was of interest primarily to intellectual property (IP) lawyers and law professors. As a computer scientist and a non-lawyer whose only interactions with IP lawyers until the past decade involved applying for patents, I was convinced that IP law was among the most boring of topics. I now find it fascinating,...
Article
Full-text available
The features of paperless direct recording electronic (DRE) voting machines are discussed. The impact of paperless DRE voting machines on the integrity of democratic process is also discussed. Due to DREs, people with disabilities can vote unassisted, human interface is improved, and ballots are changed at the last minute and quickly personalised f...
Article
The disadvantages of the Total Information Awareness (TIA) Program, sponsored by the Defense Advanced Research Projects Agency are discussed. The vast amount of information and misinformation collected by any system resulting from this program is likely to be misused to the detriment of many innocent American citizens. The state of art in computer...
Article
The article focuses on a declaration filed by the U.S.-based Association for Computing Machinery (ACM) in the federal court as of October 2001 regarding Felten v. Recording Industry Association of America case. Researcher Edward Felten and his fellow researchers at Princeton University, had entered a contest sponsored by Secure Digital Music Initia...
Conference Paper
In this paper, we present a new framework for selecting, duplicating and sequencing instructions so as to decrease register pressure. The motivation for this work is to target current and future high-performance processors where reductions in register pressure in the compiled programs can lead to improved performance.For instruction selection and d...
Article
This article presents views of the president of the periodical "Communications of the ACM," published in the May 2000 issue of the periodical, which focuses on the ongoing dispute in the field of intellectual property rights related to the issue of softw This article presents views of the president of the periodical "Communications of the ACM," pub...
Article
The article focuses on issues concerning Internet-based shopping The article focuses on issues concerning Internet-based shopping. Net-based shopping is becoming common place, and the value of Internet real estate has become obvious both to established companies and to new Net-based companies. Name recognition is synonymous with an easy-to-remember...
Article
The top three papers from the CFP 2000 student paper competition have been printed in this proceedings. They are: Internet filter effectiveness: testing over and underinclusive blocking decisions of four popular filters Christopher D. Hunter Pages ...
Article
The article focuses on dire predictions of governmental surveillance and the elimination of privacy, by computer scientist George Orwell The article focuses on dire predictions of governmental surveillance and the elimination of privacy, by computer scientist George Orwell. Many people rejoiced about the lack of omnipresent telescreens and the Thou...
Article
The article presents information on those technology and business leaders who have contributed to the extraordinary development in computing during the past half century. But there efforts have remained unacknowledged although they have worked hard to bring computer technology to those who need it, but might not otherwise have access to it. In atte...
Article
An abstract is not available.
Article
A few years ago Hollywood and the music industry discovered the Internet and realized, much to their horror, that the technology now exists to make arbitrary numbers of perfect copies of a digitized object. As a result, we have seen an explosion of legislative and treaty proposals. Legislation was recently passed that attempts to protect intellectu...
Article
Computer technology is having a pervasive influence on the lives of people in the developed world. The Internet is rapidly becoming mainstream. Both are having a growing impact on people's privacy, security, health, education, transportation, financial well-being, and even family life. Technology policy is therefore becoming a more important part o...
Conference Paper
A few years ago Hollywood and the music industry discovered the Internet and realized, much to their horror, that the technology now exists to make arbitrary numbers of perfect copies of a digitized object. As a result, we have seen an explosion of legislative and treaty proposals. Legislation was recently passed that attempts to protect intellectu...
Article
The article focuses on the star report meant for the U.S. Congress, to be posted promptly on the Internet. Following information should be made available on the Net, voting records, texts of bills and amendments, financial disclosure reports and expert testimony. The Starr Report contains material that might be considered "patently offensive" to mi...
Article
The article discusses how certain technologies like reverse engineering, with some exceptions and penetration analysis are to be outlawed. Exceptions allow reverse engineering for compatibility, encryption research, privacy protection and to protect minors against pornography. There is no stated exception for computer security research and developm...
Conference Paper
We consider the problem of sorting a file of N records on the D-disk model of parallel I/0 [VS94] in which there are two sources of parallehsm. Records are transferred to and from disk concurrently in blocks of B con-tiguous records. In each I/O operation, ...
Article
Discussion of the merits and shortcomings of affirmative action (AA) has raged at all levels and in many forums and has been the concern of many policymakers, including President Clinton. Notably absent from the discussion is the perception of AA, and the effect of the angry backlash on women and minorities. Recently, the question of whether women...
Article
Full-text available
This paper gives two simple efficient distributed algorithms: one for keeping clocks in a network synchronized and one for allowing new processors to join the network with their clocks synchronized. Assuming a fault tolerant authentication protocol, the algorithms tolerate both link and processor failures of any type. The algorithm for maintaining...
Article
We present a fast loop parallelization heuristic that assigns separate invocations of a loop to different processors. If the loop contains data dependences between iterations, later iterations can be delayed while awaiting a result computed in an earlier iteration. In this paper we study a scheduling problem, called the Delay Problem, that approxim...
Conference Paper
We present a linear time algorithm for scheduling iterations of a loop that has no loop-carried dependences. The algorithm is optimal in the sense that any p consecutive iterations in the schedule can be executed simultaneously without any possibility of false sharing, where p is the number of processors, and the algorithm uses at most two wait syn...
Conference Paper
We present an algorithm for statically analyzing the communications amongst distributed or concurrent processes that communicate using multiway synchronization, in which many processes may participate in an atomic communication action, such as in the ITU standard specification language LOTOS. This extends our previous work in which we provided an a...
Conference Paper
Full-text available
We categorize and compare different representations of program dependence graphs, including the Control Flow Graph (CFG) which is a sequential representation lacking data dependences, the Program Dependence Graph (PDG) which is a parallel representation of a sequential program and is comprised of control and data dependences, and more generally, th...
Article
Full-text available
An instruction or a set of instructions can be considered time critical if their execution is required to free up a resource. Time critical instructions might be used to make shared resources such as registers more quickly available for reuse; or they might be used for real time computations, portions of which are critical for the operation of some...
Conference Paper
We present an algorithm for analyzing deadlock and for constructing sequentializations of a class of communicating sequential processes. The algorithm may be used for deadlock detection in parallel and distributed programs at compile time, or for debugging purposes at run time. The algorithm generates a data structure we call the flow graph, which...
Article
Automatic parallelization of code written in a sequential language such as FORTRAN is of great importance for compilers for parallel computers. We first discuss the problem of automatically parallelizing iterative loops on multiprocessors and then derive a scheduling problem that models a technique for the automatic parallelization. We present some...
Conference Paper
Full-text available
Abstract An instruction or a set of instructions can be con- sidered time,critical if their execution,is required to free up a resource. Time critical instructions might,be used,to make,shared,resources such as registers more,quickly available for reuse; or they might be used for real time computations, portions of which are critical for the operat...
Article
Full-text available
An efficient polynomial time algorithm for the problem of scheduling n unit length jobs with rational release times and deadlines on m identical parallel machines is presented. By using preprocessing, a running time of $O(mn^2 )$ is obtained that is an improvement over the previous best running time of $O(n^3 \log \log n)$. The authors also present...
Chapter
As massively parallel machines come into existence, people will be writing algorithms and code tailored to these machines. Nonetheless, there remains a considerable need for optimizing parallel compilers. One inescapable fact is that there is a tremendous amount of code already written for sequential machines. Since producing software can be very c...
Conference Paper
Automatic parallelization of code written in a sequential language such as FORTRAN is of great importance. One natural approach to loop parallelization is to assign separate invocations of a loop to different processors. However, it is often necessary to delay the starting times of loops to avoid violating data dependences. In this paper we study a...
Article
Dr. Joel S. Yudken is Director of the Project on Funding Policy in Computer Science. Dr. Barbara Simons, is vice-chair of the Special Interest Group on Automata and Computability Theory (SIGACT) of the Association for Computing Machinery (ACM). Dr. Simons is also chair of the Committee on Scientific Freedom and Human Rights of the ACM. This article...
Article
We consider the problem of generating sequential code for parallel programs written in a language which contains a FORALL operator, predicates and statements. This problem can arise when compiling for a multiprocessor where each processor is sequential, and in the vectorization of sequential programs. We present a necessary and sufficient condition...
Article
We analyze the problem of constructing a network with a given number of nodes which has a fixed routing and which is highly fault tolerant. A construction is presented which forms a “product route graph” from two or more constituent “route graphs.” The analysis involves the surviving route graph, which consists of all nonfaulty nodes in the network...
Article
We construct fault-tolerant routings for several families of graphs, including all graphs of maximal degree less than for some c>0. With these routings, the diameter of the surviving graph is bounded by a constant (e.g., 4 or 6), so long as the number of faults is less than the connectivity of the graph. This result partially confirms a conjecture...
Article
Full-text available
Consider a communication network G in which a limited number of link and/or node faults F might occur. A routing p for the network (a fixed path between each pair of nodes) must be chosen without any knowledge of which components might become faulty. Choosing a good routing corresponds to bounding the diameter of the surviving route graph R(G,p)/F,...
Article
We model a communication network as a graph in which a processor is a node and a communication link is an edge. A routing for such a network is a fixed path, or route, between each pair of nodes. Given a network with a predefined routing, we study the effects of faulty components on the routing. Of particular interest is the number of routes along...
Conference Paper
Automatic parallelization of code written in a sequential language such as FORTRAN is of great importance for compilers for parallel computers. First, the problem of automatically parallelizing iterative loops on multiprocessors is discussed, and then a scheduling problem involving precedence constraints that models a technique for the automatic pa...
Article
Various aspects of the conference running problem are discussed. Solutions for some special cases are presented, and some new open problems are introduced into the literature.
Conference Paper
The VLSI placement problem consists of finding an optimum placement of the VLSI components in the plane of the chip. A standard optimization goal is to minimize the total amount of space occupied by the wires on the chip. We model the VLSI placement problem by considering the problem of placing tiles on the plane when each tile has a preassigned ar...
Conference Paper
This paper gives two simple efficient distributed algorithms: one for keeping clocks in a network synchronized and one for allowing new processors to join the network with their clocks synchronized. The algorithms tolerate both link and node failures of any type. The algorithm for maintaining synchronization will work for arbitrary networks (rather...
Article
We consider the problem of scheduling n unit-time jobs with multiple release time/deadline intervals, which are intervals of time in which the job can be scheduled. A feasible schedule is one in which each job is run in its entirety within one of its release time/deadline intervals. We show that the general problem is NP-complete, but that for a sp...
Conference Paper
We analyze the problem of constructing a network which will have a fixed routing and which will be highly fault tolerant. A construction is presented which forms a “product route graph” from two or more constituent “route graphs.” The analysis involves the surviving route graph, which consists of all non-faulty nodes in the network with two nodes b...
Article
Presents a polynomial time algorithm for constructing an optimal schedule, if a feasible schedule exists, for the following multimachine scheduling problem. There are n unit-time jobs, with arbitrary release times and deadlines, and m identical parallel machines. A feasible schedule is one in which no job is started before it is released, each job...
Article
Algorithms for the scheduling of unit-time jobs with release times and deadlines on one or many identical machines are presented and generalizations which result in NP-complete problems are discussed.
Article
The basic problem considered is that of scheduling n unit-time tasks, with arbitrary release times and deadlines, so as to minimize the maximum task completion time. Previous work has shown that this problem can be solved rather easily when all release times are integers. We are concerned with the general case in which noninteger release times are...
Conference Paper
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Article
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Contents 1 Introduction 1 1.1 The Problems : : : : : : : : : : : : : : : : : : : : : : : : : : : 2 1.2 Applications : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 1.3 The Message Flow Graph : : : : : : : : : : : : : : : : : : : : 5 1.3.1 What is a Message Flow Graph? : : : : : : : : : : : : 5 1.3.2 Loop Processes : : : : : : : : : : : :...
Article
This second course in the policy sequence provides computer graphics practitioners, developers and researchers with an in depth look at the growing conflicts between the rights of owners and users of intellectual property. The history and legal precedents of copyright will be reviewed and implications of recent treaties and laws such as those devel...

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