ppxscal/embedding_network huggingface dataset:
A Globally Convergent Method for Lp Problems
Authors: Yuyinh Li
Venue:  (1991)

The lp norm discrete estimation problem is troublesome when p is close to unity because the objective function approaches a discontinuous form. In this paper, we present an efficient approach for solving lp norm problems. When p=1, it is essentially the method presented in , which is a globally and quadradically convergent algorithm under some nondegeneracy assumptions. The existing iteratively reweighted least squares method (IRLS) can be obtained from the new approach by updating some "dual multipliers" in a special fashion. The new method is globally convergent. It is superlinearly convergent when there is no zero residual at the solution. The main computational cost of our new method is the same as the IRLS method: a reweighted least squares solve. Numerical experiments indicate this method is significantly faster than popular iteratively reweighted least squares methods when p is close or equal to one. 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
Multi-frame Isochronous Service for ATM Networks: Stop-and-Go Revisited
Authors: T. Ibaraki, T. Kameda
Venue: Proceedings of the 6th International Conference on Computer Communications and Networks (1997)

The ATM switching scheme we propose is similar to the multi-frame Stop-and-Go, except that we use the EDF (Earliest-Deadline-First) scheduler, instead of the rate-monotonic, static-priority scheduler. Unlike the multi-frame Stop-and-Go, our scheme can fully utilize the link bandwidth, and does not require that the input or output frames of the same size be synchronized. EDF scheduling is, in general, more complex than static-priority scheduling. However, we show that the next earliest deadline needs to be computed only when an output frame reaches its end, i.e., not whenever a cell is output, resulting in significant saving in computation time. We show a detailed implementation, which requires two FIFO queues per frame size per switch, and derive bounds on end-to-end delay and delay-jitters.
Power Aware Scheduling for AND/OR Graphs in Multi-Processor Real-Time Systems
Authors: Dakai Zhu, Nevine AbouGhazaleh, Daniel Mossé, Rami Melhem
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

Power aware computing has become popular recently and many techniques have been proposed to manage the energy consumption for traditional real-time applications. We have previously proposed two greedy slack sharing scheduling algorithms for such applications on multi-processor systems. In this paper, we are concerned mainly with real-time applications that have different execution paths consisting of different number of tasks. The AND/OR graph model is used to represent the application's data dependence and control flow. The contribution of this paper is twofold. First, we extend our greedy slack sharing algorithm for traditional applications to deal with applications represented by AND/OR graphs. Then, using the statistical information about the applications, we propose a few variations of speculative scheduling algorithms that intend to save energy by reducing the number of speed changes (and thus the overhead) while ensuring that the applications meet the timing constraints. The performance of the algorithms is analyzed with respect to energy savings. The results surprisingly show that the greedy scheme is better than some speculative schemes and that the greedy scheme is good enough when a reasonable minimal speed exists in the system.
Nonconvex continuous models for combinatorial optimization problems with application to satisfiability and node packing problems
Authors: Joost P. Warners
Venue:  (1997)

We show how a large class of combinatorial optimization problems can be reformulated as a nonconvex minimization problem over the unit hyper cube with continuous variables. No additional constraints are required; all constraints are incorporated in the n onconvex objective function, which is a polynomial function. The application of the general transform to satisfiability and node packing problems is discussed, and various approximation algorithms are briefly reviewed. To give an indication of the strength of the proposed approaches, we conclude with some computational results on instances of the graph coloring problem.
The Case for Enhanced Abstract Data Types
Authors: Praveen Seshadri, Miron Livny, Raghu Ramakrishnan
Venue:  (1997)

Support for complex data in object-relational database systems is based on abstract data types (ADTs). We argue that the current ADT approach inhibits the performance of queries that involve expensive operations on data types. Instead, we propose the Enhanced Abstract Data Type (E-ADT) paradigm, which treats operations on data types as declarative expressions that can be optimized. In this paper, we describe the E-ADT paradigm and PREDATOR, an object-relational database system based on E-ADTs. An E-ADT is an abstract data type enhanced with query optimization. Not only does an E-ADT provide operations (or methods) that can be used in SQL queries, it also supports internal interfaces that can be invoked to optimize these operations. This added functionality is provided without compromising the modularity of data types and the extensibility of the type system. Building such a database system requires fundamental changes in the architecture of the query processing engine; we present the system-level interfaces of PREDATOR that support E-ADTs, and describe the internal design details. Initial performance results from supporting image, time-series, and audio data as E-ADTs demonstrate an order of magnitude in performance improvements over the current ADT approach. Further, we describe how the E-ADT paradigm enables future research that can improve several aspects of object-relational query optimization. Consequently, we make the case that next-generation object-relational database systems should be based on E-ADT technology.
Combinatorial Problems in Matrix Computation
Authors: Anders Edenbrandt
Venue:  (1985)

NO SUPPLIED
Scenario-Based Reliability Analysis of Component-Based Software
Authors: Sherif M. Yacoub, Bojan Cukic, Hany H. Ammar
Venue: Proceedings of the 10th International Symposium on Software Reliability Engineering (1999)

Software designers are motivated to utilize off-the-shelf software components for rapid application development. Such applications are expected to have high reliability as a result of deploying trusted components. The claims of high reliability need further investigation based on reliability analysis techniques that are applicable to component-based applications.This paper introduces a probabilistic model and a reliability analysis technique applicable to high-level designs. The technique is named "Scenario-Based Reliability Analysis" (SBRA). SBRA is specific for component-based software whose analysis is strictly based on execution scenarios. Using scenarios, we construct a probabilistic model named "Component-Dependency Graph" (CDG). CDGs are directed graphs that represent components, component reliabilities, link and interface reliabilities, transitions, and transition probabilities. In CDGs, component interfaces and link reliabilities are treated as first class elements of the model. Based on CDGs, an algorithm is presented to analyze the reliability of the application as the function of reliabilities of its components and interfaces. A case study illustrates the applicability of the algorithm. The SBRA is used to identify critical components and critical component interfaces, and to investigate the sensitivity of the application reliability to changes in the reliabilities of components and their interfaces.
Linear Programming in Tomography, Probability, and Finance
Authors: Larry Shepp
Venue:  (1997)

At the first conference (at DIMACS), it became clear that linear, or convex, programming is going to play a key role in the algorithmics of "discrete tomography", where one attempts to reconstruct a finite subset, $S$, of the integer lattice, $Z^2$, or $Z^3$, from its line sums in a few directions obtained via transmission electron microscopy. The usual convolution-back-projection algorithms for continuous tomography are useless for this new application to crystal microscopy because only very few directions are available for which the line sums are measured. Since the problem of determining a subset $S$ with the given line sums is an integer programming problem the standard convexification of the problem reduces it to linear programming (Peter Fishburn, Peter Schwander, Robert Vanderbei, The Discrete Radon Transform and its Approximate Inversion via Linear programming, Discrete Applied Math., 1997, to appear). This showed that $S$ may be "effectively" reconstructed in the sense that the method of finding a feasible interior point in the convex hull of what is called "fuzzy sets", ie a function, $0 \le f(z) \le 1$ for all $z \in Z^2$, or $Z^3$, "typically" produces a reasonablly satisfactory reconstruction on simulated phantoms. Thus the situation is more or less analogous to conventional medical CT scanning, where even though one cannot hope to uniquely reconstruct a function, $f(x,y)$ from its line integrals in a finite number of fixed directions (even if the line integrals are noiseless) the usual algoorithms are seen to work well, as demonstrated via simulations. In the above paper written over a year ago, available by request at fish@research.att.com, the method is made clear. Here however I have a different goal: several disparate problems in applied mathematics can be solved via non-trivial use of infinite linear programming and I thought that I would share these with the audience in order to illustrate the scope and the power of linear programming and to bring the ideas to wider view, after first trying to set into perspective the application of linear programming to discrete tomography via a review. 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
Simulating a Mesh with Separable Buses by a Mesh with Partitioned Buses
Authors: Susumu Matsumae, Nobuki Tokura
Venue: Proceedings of the 1999 International Symposium on Parallel Architectures, Algorithms and Networks (1999)

We propose an algorithm that simulates a mesh with separable buses (MSB) by a mesh with partitioned buses (MPB). The MSB and the MPB are the two-dimensional mesh-connected computers which have additional broadcasting buses along every row and column. The broadcasting buses of the MSB can be dynamically sectioned into smaller bus segments of various lengths by the program control, while those of the MPB are statically partitioned in advance by a fixed length. Our algorithm takes Theta(n^{1/3}) steps to simulate the MSB of size n \times n on the MPB of size n \times n, and this time cost is shown to be optimal in the worst case. Furthermore, we discuss the advantage of the MPB, considering the influence of propagation delays of the broadcasting buses.
Time consistency of MSC-2000 specifications
Authors: Tong Zheng, Ferhat Khendek
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2003)

Message Sequence Charts (MSC) is a formal language for the specification of behavioral scenarios and use cases. In the latest standard, time constructs have been added to the language to handle real-time constraints specification. In this paper, we investigate the time consistency of MSC-2000 specifications. Both basic MSCs and high-level MSCs (HMSCs) are taken into account. However, the focus is on HMSCs. We define the notion of consistency for basic MSCs and the notions of strong and weak consistency for HMSCs. We also develop and analyze algorithms for checking the time consistency of MSCs.
On the Limitations of Bubble Functions
Authors: Leopoldo Franca, Charbel Farhat
Venue:  (1993)

We present two examples that demonstrate no advantage in enriching a finite element subspace with bubble functions.
Numerical solution of a convection diffusion problem with Robin boundary conditions
Authors: Ali R. Ansari, Alan F. Hegarty
Venue: Journal of Computational and Applied Mathematics (2003)

We consider a one-dimensional steady-state convection dominated convection-diffusion problem with Robin boundary conditions. We show, both theoretically and with numerical experiments, that numerical solutions obtained using an upwind finite difference scheme on Shishkin meshes are uniformly convergent with respect to the diffusion coefficient.
Splitting and contractible edges in 4-connected graphs
Authors: Akira Saito
Venue: Journal of Combinatorial Theory Series B (2003)

Let G be a graph and let x be a vertex of degree four with NG(x) = {a, b, c, d}. Then the operation of deleting x and adding the edges ab and cd is called splitting at x. An edge e of a graph G is said to be k-contractible if contraction of e yields a k-connected graph. Splitting has been studied as a reduction method to preserve edge-connectivity. In this paper, we consider splitting and 4-contractible edges as tools for reduction of 4-connected graphs. We prove that for a 4-connected graph G of order at least six, there exists either a 4-contractible edge or a vertex eligible for splitting preserving 4-connectedness near every vertex in G.
High-speed parameterisable Hough transform using reconfigurable hardware
Authors: Dixon D. S. Deng, Hossam ElGindy
Venue: Proceedings of the Pan-Sydney area workshop on Visual information processing - Volume 11 (2001)

Recent developments in reconfigurable hardware technologies have offered high-density high-speed devices with the ability for custom computing whilst maintaining the flexibility of a software solution. These features are well suited to image processing algorithms that are computationally intensive and repetitive in nature. Very deep pipelining and parallelism, features often required for real time image analysis can be achieved easily using hardware design. The Hough Transform is a powerful and robust global image processing tool for feature recognition and detection. The CORDIC algorithm uses simple shift and addition operations to implement complex trigonometric functions. This paper combines the application of the novel CORDIC algorithm to the Hough Transform and reconfigurable technology to propose a parameterisable Hough Transform with real-time processing throughput.
Specifying and Enforcing Application-Level Web Security Policies
Authors: David Scott, Richard Sharp
Venue: IEEE Transactions on Knowledge and Data Engineering (2003)

Application-level Web security refers to vulnerabilities inherent in the code of a Web-application itself (irrespective of the technologies in which it is implemented or the security of the Web-server/back-end database on which it is built). In the last few months, application-level vulnerabilities have been exploited with serious consequences: Hackers have tricked e-commerce sites into shipping goods for no charge, usernames and passwords have been harvested, and confidential information (such as addresses and credit-card numbers) has been leaked. In this paper, we investigate new tools and techniques which address the problem of application-level Web security. We 1) describe a scalable structuring mechanism facilitating the abstraction of security policies from large Web-applications developed in heterogeneous multiplatform environments; 2) present a set of tools which assist programmers in developing secure applications which are resilient to a wide range of common attacks; and 3) report results and experience arising from our implementation of these techniques.
A high-level programming environment for packet trace anonymization and transformation
Authors: Ruoming Pang, Vern Paxson
Venue: Proceedings of the 2003 conference on Applications, technologies, architectures, and protocols for computer communications (2003)

Packet traces of operational Internet traffic are invaluable to network research, but public sharing of such traces is severely limited by the need to first remove all sensitive information. Current trace anonymization technology leaves only the packet headers intact, completely stripping the contents; to our knowledge, there are no publicly available traces of any significant size that contain packet payloads. We describe a new approach to transform and anonymize packet traces. Our tool provides high-level language support for packet transformation, allowing the user to write short policy scripts to express sophisticated trace transformations. The resulting scripts can anonymize both packet headers and payloads, and can perform application-level transformations such as editing HTTP or SMTP headers, replacing the content of Web items with MD5 hashes, or altering filenames or reply codes that match given patterns. We discuss the critical issue of verifying that anonymizations are both correctly applied and correctly specified, and experiences with anonymizing FTP traces from the Lawrence Berkeley National Laboratory for public release.
Panel 2: Doing Software Maintenance for Business Change
Authors: Ned Chapin
Venue: Proceedings of the IEEE International Conference on Software Maintenance (1999)

The Conference theme this year is "software maintenance for business change." This panel is on that theme. After setting the stage with where we are, the panel expects to cover at least a dozen ways that software maintenance should be done for business change, some of them incompatible with each other. 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
Addition Requirements for Rational Functions
Authors: David G. Kirkpatrick, Zvi M. Kedem
Venue:  (1975)

A notion of rank or independence for arbitrary sets of rational functions is developed, which bounds from below the number of additions and subtractions required of all straight-line algorithms which compute those functions. This permits a uniform derivation of the best lower bounds known for a number of familiar sets of rational functions. The result is proved without the use of substitution arguments. This not only provides an interesting contrast to standard approaches for arithmetic lower bounds, but also allows the algebraic setting to be somewhat generalized. Keywords: additions, algorithms, analysis of algorithms, arithmetic complexity, computational complexity, dimensionality, lower bounds, matrix multiplication, optimality, polynomials, rational functions.
GESIA: Uncertainty-Based Reasoning for a Generic Expert System Intelligent User Interface
Authors: Robert A. Harrington, Sheila Banks, Eugene Santos Jr.
Venue: Proceedings of the 8th International Conference on Tools with Artificial Intelligence (1996)

Generic expert systems are reasoning systems that can be used in many application domains, thus requiring domain independence. The user interface for a generic expert system must contain an intelligence in order to maintain this domain independence and manage the complex interactions between the user and the expert system. This paper explores the uncertainty-based reasoning contained in an intelligent user interface called GESIA. GESIA's interface architecture and dynamically constructed Bayesian network are examined in detail to show how uncertainty-based reasoning enhances the capabilities of this user interface.
Parsing in a Visual Language Environment
Authors: Eric J. Golin, Steven P. Reiss
Venue:  (1989)

Visual programming languages use pictures as programs. A visual programming environment supports the creation of visual programs. A spatial parser recovers the underlying structure of a visual program from the picture. We describe how a spatial parser can be used to form the basis of a language-independent visual programming environment. A new model for specifying the syntax of visual language, the Picture Layout Grammar, is described. Finally, an algorithm for parsing visual programs based on a PLG specification is given.
Automatic ranking of retrieval systems in imperfect environments
Authors: Rabia Nuray, Fazli Can
Venue: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval (2003)

The empirical investigation of the effectiveness of information retrieval (IR) systems requires a test collection, a set of query topics, and a set of relevance judgments made by human assessors for each query. Previous experiments show that differences in human relevance assessments do not affect the relative performance of retrieval systems. Based on this observation, we propose and evaluate a new approach to replace the human relevance judgments by an automatic method. Ranking of retrieval systems with our methodology correlates positively and significantly with that of human-based evaluations. In the experiments, we assume a Web-like imperfect environment: the indexing information for all documents is available for ranking, but some documents may not be available for retrieval. Such conditions can be due to document deletions or network problems. Our method of simulating imperfect environments can be used for Web search engine assessment and in estimating the effects of network conditions (e.g., network unreliability) on IR system performance.
A Practical Guide to Curl
Authors: Kevin Hanegan
Venue:  (2003)

:Kevin Hanegan (Marlboro, MA) is a course developer and trainer for Spotfire Inc., and has worked for a variety of companies as a trainer and consultant. He is the author of Custom CGI Scripting with Perl. 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
Economic Analysis of a Stopping-Rule in Branch Coverage Testing
Venue: Proceedings of the 3rd International Symposium on Quality Electronic Design (2002)

This paper argues that software testing can be less thorough yet more cost-efficient if applied in a well-managed, empirical manner across the entire Software Development Life Cycle (SDLC). This is done by showing the cost-benefit analyses among other criteria. To ensure success, testing must be planned and executed within an Earned Value Management (EVM) paradigm as the experiment is conducted on a statistical-process controlled mindset. The Stopping Rule (MESAT) is applied to an actual embedded-chip software development cycle to show potential gains compared to archaic testing methods or none that were used. The result is that a considerable percentage of the particular testing effort could have been saved under usual circumstances, had the testing been planned and executed under EVM with the MESAT algorithm. 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
Image Databases: Search and Retrieval of Digital Imagery
Authors: Vittorio Castelli, Lawrence D. Bergman
Venue:  (2002)

:The explosive growth of multimedia data transmission has generated a critical need for efficient, high-capacity image databases, as well as powerful search engines to retrieve image data from them. This book brings together contributions by an international all-star team of innovators in the field who share their insights into all key aspects of image database and search engine construction. Readers get in-depth discussions of the entire range of crucial image database architecture, indexing and retrieval, transmission, display, and user interface issues. And, using examples from an array of disciplines, the authors present cutting-edge applications in medical imagery, multimedia communications, earth science, remote sensing, and other major application areas.