ppxscal/embedding_network huggingface dataset:
Verifying security protocols with Brutus
Authors: E. M. Clarke, S. Jha, W. Marrero
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (2000)

Due to the rapid growth of the &ldquo;Internet&rdquo; and the &ldquo;World Wide Web&rdquo; security has become a very important concern in the design and implementation of software systems. Since security has become an important issue, the number of protocols in this domain has become very large. These protocols are very diverse in nature. If a software architect wants to deploy some of these protocols in a system, they have to be sure that the protocol has the right properties as dictated by the requirements of the system. In this article we present BRUTUS, a tool for verifying properties of security protocols. This tool can be viewed as a special-purpose model checker for security protocols. We also present reduction techniques that make the tool efficient. Experimental results are provided to demonstrate the efficiency of BRUTUS.
Mechanical modeling of soft biological tissues for application in virtual reality based laparoscopy simulators
Authors: Roland Hutter, Kai-Uwe Schmitt, Peter Niederer
Venue: Technology and Health Care (2000)

For application in a Virtual Reality (VR) based laparoscopic surgery simulator, computationally efficient algorithms for the description of the mechanical behavior of soft tissue have been developed. The explicit Finite Element Method has turned out to be a robust method for this purpose provided that absolute strain formulations are applied. Furthermore, a VR model of a uterus and its adnexe has been generated and simulation results are presented.
Regulatory element detection using correlation with expression (abstract only)
Authors: Harmen J. Bussemaker, Hao Li, Eric D. Siggia
Venue: Proceedings of the fifth annual international conference on Computational biology (2001)

We present a new computational method for discovering cis- regulatory elements which circumvents the need to cluster genes based on their expression profiles. Based on a model in which upstream motifs contribute additively to the expression level of a gene, it requires a single genome-wide set of expression ratios and the upstream sequence for each gene, and outputs statistically significant motifs. Analysis of publicly available expression data for Sac charomyes cerevisiae reveals several new putative regulatory elements, some of which plausibly control the early, transient induction of genes during sporulation. Known motifs generally have high statistical significance.
Using encryption for authentication in large networks of computers
Authors: Roger M. Needham, Michael D. Schroeder
Venue: Communications of the ACM (1978)

Use of encryption to achieve authenticated communication in computer networks is discussed. Example protocols are presented for the establishment of authenticated connections, for the management of authenticated mail, and for signature verification and document integrity guarantee. Both conventional and public-key encryption algorithms are considered as the basis for protocols.
Algorithms for Defining Visual Regions-of-Interest: Comparison with Eye Fixations
Authors: Claudio M. Privitera, Lawrence W. Stark
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

Many machine vision applications, such as compression, pictorial database querying, and image understanding, often need to analyze in detail only a representative subset of the image, which may be arranged into sequences of loci called regions-of-interest, ROIs. We have investigated and developed a methodology that serves to automatically identify such a subset of aROIs (algorithmically detected ROIs) using different Image Processing Algorithms, IPAs, and appropriate clustering procedures. In human perception, an internal representation directs top-down, context-dependent sequences of eye movements to fixate on similar sequences of hROIs (human identified ROIs). In this paper, we introduce our methodology and we compare aROIs with hROIs as a criterion for evaluating and selecting bottom-up, context-free algorithms. An application is finally discussed.
Towards virtual videography (poster session)
Authors: Michael Gleicher, James Masanz
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

Videographers have developed an art of conveying events in video. Through choices made in cinematography, editing, and post-processing, effective video presentations can be created from events recorded with little or no intrusion. In this paper, we explore systems that bring videography to situations where cost or time issues preclude application of the art. Our goal is to develop virtual videography, that is, systems that can help automate the process of creating an effective video presentation from given footage. In this paper, we discuss how virtual videography systems can be constructed by combining image-based rendering to synthetically generate shots with image understanding to help choose what should be shown to the viewer. To this, visual effects can be added to enhance the presentation, lessening the degradation caused by the medium.
Symbolic RTL simulation
Authors: Alferd Kölbl, James Kukula, Robert Damiano
Venue: Proceedings of the 38th annual Design Automation Conference (2001)

Symbolic simulation is a promising formal verification technique combining the flexibility of conventional simulation with powerful symbolic methods. Unfortunately, existing symbolic simulators are restricted to gate level simulation or handle just a synthesizable subset of an HDL. Simulation of systems composed of design, testbench and correctness checkers, however, requires the complete set of HDL constructs. We present an approach that enables symbolic simulation of the complete set of RT-level Verilog constructs with full delay support. Additionally, we propose a flexible scheme for introducing symbolic variables and demonstrate how error traces can be simulated with this new scheme. Finally, we present some experimental results on an 8051 micro-controller design which prove the effectiveness of our approach.
Abstraction and verification in Alphard: defining and specifying iteration and generators
Authors: Mary Shaw, William A. Wulf, Ralph L. London
Venue: Communications of the ACM (1977)

The Alphard &ldquo;form&rdquo; provides the programmer with a great deal of control over the implementation of abstract data types. In this paper the abstraction techniques are extended from simple data representation and function definition to the iteration statement, the most important point of interaction between data and the control structure of the language itself. A means of specializing Alphard's loops to operate on abstract entities without explicit dependence on the representation of those entities is introduced. Specification and verification techniques that allow the properties of the generators for such iterations to be expressed in the form of proof rules are developed. Results are obtained that for common special cases of these loops are essentially identical to the corresponding constructs in other languages. A means of showing that a generator will terminate is also provided.
An alternate checksum method
Authors: N. S. Newhall
Venue: Communications of the ACM (1964)

To increase reliability of transmission between magnetic tape and core storage on an IBM 7090/7094, blocks or records of data are often assigned a word called a logical checksum. This is a number derived from the block by some simple algorithm and as unique to it as possible. The method most commonly used to form a checksum is to add together every datum in the block by the ACL (add and carry logical) instruction.
Characterization-free behavioral power modeling
Authors: A. Bogliolo, L. Benini, G. De Micheli
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

We propose a new approach to RT-level power modeling for combinational macros, that does not require simulation-based characterization. A pattern-dependent power model for a macro is analytically constructed using only structural information about its gate-level implementation. The approach has three main advantages over traditional techniques: i) it provides models whose accuracy does not depend on input statistics, ii) it offers a wide range of trade-off between accuracy and complexity, and iii} it enables the construction of pattern-dependent conservative upper bounds.
Robustness and Scalability of Algebraic Multigrid
Authors: Andrew J. Cleary, Robert D. Falgout, Van Emden Henson, Jim E. Jones, Thomas A. Manteuffel, Stephen F. McCormick, Gerald N. Miranda, John W. Ruge
Venue: SIAM Journal on Scientific Computing (1999)

Algebraic multigrid (AMG) is currently undergoing a resurgence in popularity, due in part to the dramatic increase in the need to solve physical problems posed on very large, unstructured grids. While AMG has proved its usefulness on various problem types, it is not commonly understood how wide a range of applicability the method has. In this study, we demonstrate that range of applicability, while describing some of the recent advances in AMG technology. Moreover, in light of the imperatives of modern computer environments, we also examine AMG in terms of algorithmic scalability. Finally, we show some of the situations in which standard AMG does not work well and indicate the current directions taken by AMG researchers to alleviate these difficulties.
A PL/1 program to assist the comparative linguist
Authors: Donald G. Frantz
Venue: Communications of the ACM (1970)

A practical PL/1 program is described which can assist comparative linguists to determine the regular sound correspondences between genetically related languages. The investigator must arrange data for input by aligning pairs of suspected cognates. The program tabulates the correspondences, and uses list processing techniques to sort and count them. Each pair of words is then assigned a relative value that is a function of the total frequency in the data of each correspondence found in that pair of words. The output is a list of all correspondence types with their frequency of occurrence in the data, and a separate listing of each correspondence with all wordpairs showing that correspondence (unless their relative value is below an arbitrarily chosen cutoff point). The article explains the usefulness, as well as the limitations, of the program, and illustrates its use with a small portion of hypothetical data.
Reentrant polygon clipping
Authors: Ivan E. Sutherland, Gary W. Hodgman
Venue: Communications of the ACM (1974)

A new family of clipping algorithms is described. These algorithms are able to clip polygons against irregular convex plane-faced volumes in three dimensions, removing the parts of the polygon which lie outside the volume. In two dimensions the algorithms permit clipping against irregular convex windows. Polygons to be clipped are represented as an ordered sequence of vertices without repetition of first and last, in marked contrast to representation as a collection of edges as was heretofore the common procedure. Output polygons have an identical format, with new vertices introduced in sequence to describe any newly-cut edge or edges. The algorithms easily handle the particularly difficult problem of detecting that a new vertex may be required at a corner of the clipping window. The algorithms described achieve considerable simplicity by clipping separately against each clipping plane or window boundary. Code capable of clipping the polygon against a single boundary is reentered to clip against subsequent boundaries. Each such reentrant stage of clipping need store only two vertex values and may begin its processing as soon as the first output vertex from the preceeding stage is ready. Because the same code is reentered for clipping against subsequent boundaries, clipping against very complex window shapes is practical. For perspective applications in three dimensions, a six-plane truncated pyramid is chosen as the clipping volume. The two additional planes parallel to the projection screen serve to limit the range of depth preserved through the projection. A perspective projection method which provides for arbitrary view angles and depth of field in spite of simple fixed clipping planes is described. This method is ideal for subsequent hidden-surface computations.
Copying list structures using bounded workspace
Authors: Gary Lindstrom
Venue: Communications of the ACM (1974)

Two new algorithms are presented for list structure copying using bounded workspace. The first, of primarily theoretical interest, shows that without cell tag bits the task can be performed in time n2. The second algorithm, assuming one tag bit in each cell, delivers attractive practical speed. Any noncyclic structure is copied in linear speed, while cyclic structures are copied in average time less than n log n. No foreknowledge of cycle absence is necessary to achieve linear speed. A variation of the second algorithm solves an open problem concerning list structure marking. That result demonstrates that marking can be done in average time n log n without the aid of supplemental tag bits or stacks.
Subexpression ordering in the execution of arithmetic expressions
Authors: C. V. Ramamoorthy, M. J. Gonzalez
Venue: Communications of the ACM (1971)

An arithmetic expression can often be broken down into its component subexpressions. Depending on the hardware environment in which the expression is to be executed, these subexpressions can be evaluated in serials, in parallel, or in a combination of these modes. This paper shows that expression execution time can be minimized only if consideration is given to the ordering of the subexpressions. In particular, subexpressions should be executed in order of decreasing memory and processor time requirements. This observation is valid for configurations ranging from a uniprocessor with an unbuffered main memory to a multiprocessor with a &ldquo;cache&rdquo; buffer memory. If the number of subexpressions which can be executed in parallel exceeds the number of available processors, then execution of some of these subexpressions must be postponed. A procedure is given which combines this requirement with the earlier ordering considerations to provide an optimal execution sequence.
Toward a Mathematical Foundation of Software Engineering Methods
Authors: Manfred Broy
Venue: IEEE Transactions on Software Engineering (2001)

The development of large software systems consists of a sequence of modeling tasks. It requires the modeling and description of the application domain, software requirements, software architecture, software components, their internal structure, and their implementation. Technically, in software engineering, we work with a development method and description techniques with modeling, refinement, and implementation concepts. Today, much of the modeling is carried out by informal text and graphical description techniques. The development is organized in a development process and supported by CASE tools. In this paper, we show how mathematics can provide a scientific foundation for the modeling aspects, description techniques, and development methods of software engineering. Such a scientific foundation leads to a deeper understanding of the development process and to a basis for a more powerful tool support.
IAMC architecture and prototyping: a progress report
Authors: P. Wang, S. Gray, N. Kajler, D. Lin, W. Liao, X. Zou
Venue: Proceedings of the 2001 international symposium on Symbolic and algebraic computation (2001)

Internet Accessible Mathematical Computation (IAMC) is a distributed framework to supply mathematical computing powers over the Internet. Presented are conceptual and experimental work on the IAMC architecture, a client prototype (Dragonfly), client GUI, a server prototype (Starfish), the Mathematical Computation Protocol (MCP), mathematical data encoding, and the external compute engine interface.
Evaluation and selection of file organization&mdash;a model and system
Authors: Alfonso F. Cardenas
Venue: Communications of the ACM (1973)

This work first discusses the factors that affect file (data base) organization performance, an elusive subject, and then presents a methodology, a model and a programmed system to estimate primarily total storage costs and average access time of several file organizations, given a specific data base, query characterization and device-related specifications. Based on these estimates, an appropriate file structure may be selected for the specific situation. The system is a convenient tool to study file structures and to facilitate as much as possible the process of data base structure design and evaluation.
Modern software development concepts: a new philosophy for CS2
Authors: Paul T. Tymann, G. Michael Schneider
Venue: ACM SIGCSE Bulletin (2000)

In this paper we propose a significantly different approach to CS2, the second course in the undergraduate computer science curriculum. Rather than a central focus on the design and implementation of data structures, we propose that the central focus be on modern software development concepts such as object-oriented design, exceptions, GUIs, graphics, collection classes, threads, and networking. We believe that these are the important concepts that students should be exposed to and should use in the second computer science course.
Eigenvectors of a 2n &times; 2n matrix
Authors: S. Charmonman
Venue: Communications of the ACM (1967)

It has been known that the eigenvalues of a certain 2n &times; 2n matrix can be obtained by use of two smaller matrices of order n which can be easily constructed. An algorithm is given to obtain the eigenvectors of the 2n &times; 2n matrix by use of the eigenvectors of the smaller matrices.
A distributed detection framework for Steganalysis
Authors: R. Chandramouli, Nasir D. Memon
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

Many watermarking algorithms have been proposed and studied for their robustness and other properties. But, there has been little effort is analyzing these algorithms for their vulnerability against detection by an adversary. As a general philosophy for robust watermarking the host signal and the watermarked signal are well separated in a statistical distance sense. This very nature can be exploited by an adversary to easily detect the watermark and perhaps remove it. We argue that the ability of a watermark to avoid detection by an adversary is a key factor that needs more attention. In this paper, we propose a framework, based on a distributed detection technique, that can be used by the adversary to study signals for the presence/absence of watermarks. We choose a particular spatial domain image watermarking algorithm and explain how the proposed framework can be applied to detect the watermark with very little knowledge about the watermark insertion procedure. The false alarm probability can be optimally traded-off with the probability of detection using the receiver operating characteristic function.
A WWW-based multimedia center for learning data communications &mdash; phase 1
Authors: Ali Elkateeb, Ala Awad
Venue: ACM SIGCSE Bulletin (2000)

The use of multimedia in education has become an important element to improve the quality of education and to reduce the cost of the educational system. In addition, the students got the benefit of learning and understanding the material better than in the conventional way. In this work, a learning package called "Data Communications Learning Center" (DCLC) has been developed and tested. The main objective of this center is to help university students and others to learn data communication concepts, architectures and operations. The center is a world wide web (www) based, and it allows any student that uses a standard modem for the Internet access to use our center. The center has been developed to be easy to use. The initial evaluation of the center examined by a few students have complemented that the center has improved their understanding to some data communication concepts which the center already supports. Although our intention is to support one topic at the first stage of this project, one can easily add other topics to the center. Any professor who is willing to put his course in the center can achieve this without any prior knowledge about the internal design of the center.
Distance Matrix Completion by Numerical Optimization
Authors: Michael W. Trosset
Venue: Computational Optimization and Applications (2000)

Consider the problem of determining whether or not a partial dissimilarity matrix can be completed to a Euclidean distance matrix. The dimension of the distance matrix may be restricted and the known dissimilarities may be permitted to vary subject to bound constraints. This problem can be formulated as an optimization problem for which the global minimum is zero if and only if completion is possible. The optimization problem is derived in a very natural way from an embedding theorem in classical distance geometry and from the classical approach to multidimensional scaling. It belongs to a general family of problems studied by Trosset (Technical Report 97-3, Department of Computational Applied Mathematics&mdash;MS 134, Rice University, Houston, TX 77005-1892, 1997) and can be formulated as a nonlinear programming problem with simple bound constraints. Thus, this approach provides a constructive technique for obtaining approximate solutions to a general class of distance matrix completion problems.
Parallel processing for 2-1/2D machining simulation
Authors: A. D. Spence, Z. Li
Venue: Proceedings of the sixth ACM symposium on Solid modeling and applications (2001)

Continued progress in the area of solid modeler based machining process simulation is hindered by the complexity growth that occurs for a large number of tool paths n. For this reason, many researchers have adopted the Z-buffer approach. Boundary-representation (B-rep), however, remains the dominant choice for commercial modelers. This paper begins by reviewing the current state of solid modeler based machining simulation. Using an industrial example, the growth rate, for a simple feed rate scheduling application, is estimated to be O(n1.5). It is shown that round robin parallel scheduling quickly becomes inefficient due to the fraction of time spent on tool swept volume Boolean subtractions. The tool path sequence is next heuristically subdivided into nearly equal size neighbor groups. Only the Boolean subtractions required for accurate simulation are included in the group. Each group is then simulated in parallel, achieving a greatly reduced wall clock running time. Computational geometry methods are described that permit rapid identification of tool path neighbors. It is shown that, under practical assumptions, the total number of tool path neighbor pairs is O(n), justifying the benefit of parallel processing. Both dual CPU and networked parallel solutions are implemented. Geometric images and running time plots are included to illustrate. Discussion is included, with proposed steps to further reduce calculation time.
Comment on Cheney's list-compaction algorithm
Authors: Robert R. Fenichel
Venue: Communications of the ACM (1971)

C.J. Cheney [2] implicitly assumes that cells of list storage are self-identifying. Cheney needs this assumption so that his algorithm, when linearly scanning the memory containing a copy of a list, can determine whether particular bit patterns within that memory are pointers to other list structure. The assumption is strong, and its effect is contrary to that of the list compaction which is his algorithm's purpose.