ppxscal/embedding_network huggingface dataset:
Estimating the Failure Rate of Evolving Software Systems
Authors: Daniel R. Jeske, M. Akber Qureshi
Venue: Proceedings of the 11th International Symposium on Software Reliability Engineering (2000)

Lucent TechnologiesWhen software is tested according to the customer's operational profile, many techniques exist in the literature for using the resulting failure data to estimate the customer-perceived failure rate. Unfortunately, the overhead associated with defining and using the customer's operational profile during system test can be significant. As a compromise, many projects test the software by executing it over a sustained period using simulated load scenarios the represent informed judgments of what the customer environment is likely to be. By itself, the load test data is suspect for estimating the customer-perceived failure rate since the load scenarios may not be accurate representations of the customer's usage patterns. In addition, the load test data is limited by the relatively small amount of time that is set aside for load testing.In many cases, the software being tested is an evolution of a previous release already in the field. The field experience with the previous release along with a characterization of the difference between the two releases are natural sources of information for building a prior distribution of the failure rate of the new release. The load test data can be used to obtain a posterior distribution of the failure rate of the new release. The posterior distribution inherently reflects the customer's operational profile through its dependence on the field data, and effectively enlarges the set of data from which inference about the failure rate of the new release is to be made. In this paper, we develop a model for the prior distribution of the failure rate, and obtain the corresponding posterior distribution. We illustrate our modeling approach using real data collected from one of our software products.
Hypercube Algorithms on the Polymorphic Torus
Authors: Anne C. Elster, Hungwen Li
Venue:  (1989)

The Polymorphic Torus architecture is a reconfigurable, massively parallel finegrained system, which in its two-dimensional $(N^{2})$ case has a lower wiring complexity than, say, hypercubes. However, due to the dynamic connection features at run-time, it allows several parallel structures such as trees, rings, and hypercubes to be emulated efficiently. In this paper, we consider algorithms that are especially well-suited for hypercubes, i.e. algorithms that take advantage of the relatively high connectivity of the hypercube topology, and show how these algorithms attain comparable bounds on a 2-D Polymorphic Torus. In particular, algorithms for dense matrix vector multiplication (including using 2 orthogonal trees for the matrix-vector case), sparse matrix-vector multiplication, and the FFT are discussed.
Scalable Consistency Maintenance in Content Distribution Networks Using Cooperative Leases
Authors: Anoop George Ninan Purushottam Kulkarni Prashant Shenoy, Krithi Ramamritham
Venue: IEEE Transactions on Knowledge and Data Engineering (2003)

In this paper, we argue that cache consistency mechanisms designed for stand-alone proxies do not scale to the large number of proxies in a content distribution network and are not flexible enough to allow consistency guarantees to be tailored to object needs. To meet the twin challenges of scalability and flexibility, we introduce the notion of cooperative consistency along with a mechanism, called cooperative leases, to achieve it. By supporting \Delta{\hbox{-}}{\rm{consistency}} semantics and by using a single lease for multiple proxies, cooperative leases allow the notion of leases to be applied in a flexible, scalable manner to CDNs. Further, the approach employs application-level multicast to propagate server notifications to proxies in a scalable manner. We implement our approach in the Apache Web server and the Squid proxy cache and demonstrate its efficacy using a detailed experimental evaluation. Our results show a factor of 2.5 reduction in server message overhead and a 20 percent reduction in server state space overhead when compared to original leases albeit at an increased interproxy communication overhead.
Optimal Allocation of Testing Resources for Modular Software Systems
Authors: Chin-Yu Huang, Jung-Hua Lo, Sy-Yen Kuo, Michael R. Lyu
Venue: Proceedings of the 13th International Symposium on Software Reliability Engineering (2002)

In this paper, based on software reliability growth models with generalized logistic testing-effort function, we study three optimal resource allocation problems in modular software systems during testing phase:1) minimization of the remaining faults when a fixed amount of testing-effort and a desired reliability objective are given,2) minimization of the required amount of testing-effort when a specific number of remaining faults and a desired reliability objective are given, and 3) minimization of the cost when the number of remaining faults and a desired reliability are given.Several useful optimization algorithms based on the Lagrange multiplier method are proposed and numerical examples are illustrated.Our methodologies provide practical approaches to the optimization of testing resource allocation with a reliability objective.In addition, we also introduce the testing-resource control problem and compare different resource allocation methods.Finally, we demonstrate how these analytical approaches can be employed in the integration testing.Using the proposed algorithms, project managers can allocate limited testing resource easily and efficiently and thus achieve the highest reliability objective during software module and integration testing.
Progress Measures for Verification Involving Nondeterminism
Authors: Nils Klarlund, Fred B. Schneider
Venue:  (1990)

Using the notion of progress measures, we give a complete verification method for proving that a program satisfies a property specified by an automaton having bounded nondeterminism. Such automata can express any safety property. Previous methods, which can be derived from the method presented here, either rely on transforming the program or are not complete.
Popularity-Based PPM: An Effective Web Prefetching Technique for High Accuracy and Low Storage
Authors: Xin Chen, Xiaodong Zhang
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

Prediction by Partial Match (PPM) is a commonly used technique in Web prefetching, where prefetching decisions are made based on historical URLs in a dynamically maintained Markov prediction tree. Existing approaches either widely store the URL nodes by building the tree with a fixed height in each branch, or only store the branches with frequently accessed URLs. Building the popularity information into the Markov prediction tree, we propose a new prefetching model, called popularity-based PPM. In this model, the tree is dynamically updated with a variable height in each set of branches where a popular URL can lead a set of long branches, and a less popular document leads a set of short ones. Since majority root nodes are popular URLs in our approach, the space allocation for storing nodes are effectively utilized. We have also included two additional optimizations in this model: (1) directly linkinga root node to duplicated popular nodes in a surfing path to give popular URLs more considerations for prefetching; and (2) making a space optimization after the tree is built tofurther remove less popular nodes. Our trace-driven simulation results comparatively show a significant space reduction and an improved prediction accuracy of the proposed prefetching technique.
Toward a Theory of Information Preservation
Authors: James Cheney, Carl Lagoze, Peter Botticelli
Venue:  (2001)

Digital preservation is a pressing challenge to the library community. In this paper, we describe the initial results of our efforts towards understanding digital (as well as traditional) preservation problems from first principles. Our approach is to use the language of mathematics to formalize the concepts that are relevant to preservation. Our theory of _preservation spaces_ draws upon ideas from logic and programming language semantics to describe the relationship between concrete objects and their information contents. We also draw on game theory to show how objects change over time as a result of uncontrollable environment effects and directed preservation actions. In the second half of this paper, we show how to use the mathematics of universal algebra as a language for objects whose information content depends on many components. We use this language to describe both migration and emulation strategies for digital preservation.
Ordered Delivery over One-Way Virtual Circuits
Authors: Jorge A. Cobb, Mohamed G. Gouda
Venue: Proceedings of the IEEE Symposium on Computers and Communications (ISCC'95) (1995)

We present a family of transport protocols for transmitting messages from a sender process to a receiver process over multiple one-way channels (that represent virtual circuits). Each channel may lose but not reorder nor duplicate messages. The sender process distributes its messages among the channels in a round-robin manner for purposes of load balancing and fault-tolerance. The receiver process receives messages from the different channels in arbitrary order, but it delivers them in the same order in which they were sent, despite the fact that some messages may have been lost during transmission. The protocols in our protocol family support two delivery requirements: no deadline delivery, in which the receiver may wait to receive a message from each channel before delivering the next message, and deadline delivery, in which each message is to be delivered before a given deadline.
Fourth order linear differential equations with imprimitive group
Authors: Delphine Boucher, Philippe Gaillard, Felix Ulmer
Venue: Proceedings of the 2003 international symposium on Symbolic and algebraic computation (2003)

In this paper we study fourth order linear differential equations whose differential Galois groups are imprimitive. We derive optimal bounds for the degree of the minimal polynomial of the logarithmic derivative of a Liouvillian solution. This is the lowest possible order where imprimitive non monomial groups occur.
Segmentation vs. Non-Segmentation Based Neural Techniques for Cursive Word Recognition: An Experimental Analysis
Authors: Xialong Fan, Brijesh Verma
Venue: Proceedings of the Fourth International Conference on Computational Intelligence and Multimedia Applications (2001)

This paper compares segmentation-based and non-segmentation based techniques forcursive word recognition.In our segmentation based technique, every word is segmentedinto characters, the chain code features are extracted from segmented characters, thefeatures are fed to neural network classifier and finally the words are constructed using astring compare algorithm.In our non-segmentation based technique, the chain codefeatures are extracted directly from words and the words are fed to a neural networkclassifier to classify them into word classes.To make fair comparison, CEDAR benchmarkdatabase is used, and the parameters such as the number of words, thresholding, resizing,feature extraction techniques, etc., are kept same for both the techniques.Experimentalresults show that the non-segmentation technique achieves much higher recognition ratethan the segmentation based technique.
A Method for Proving Lower Bounds for Certain Geometric Problems
Authors: Raimund Seidel
Venue:  (1984)

We prove lower bounds for a number of geometric problems. Our results show that certain types of additional input information cannot possibly permit faster solutions for these problems. The main idea in all our lower bound proofs is the use of the index of a point as an additional coordinate.
On Queuing with Customer Impatience until the End of Service
Authors: Ali Movaghar
Venue: Proceedings of the 4th International Computer Performance and Dependability Symposium (2000)

We study queuing systems where customers have strict deadlines until the end of their service. An analytic method is given for the analysis of a class of such queues, namely, M(n)/M/1+G models with ordered service. These are single-server queues with state-dependent Poisson arrival process, exponential service times, FCFS service discipline, and general customer impatience. We derive a closed-form solution for the conditional probability density function of the offered sojourn time, given the number of customers in the system. This is a novel result that has not been known before. Using this result, we show how the probability measure induced by the offered sojourn time is computed, and consequently how performance measures such as the probability of missing deadline and the probability of blocking are obtained. This is further illustrated through a numerical example.
A VLSI based real-time hidden surface elimination display system
Authors: Stefan G. Demetrescu
Venue:  (1980)

This thesis describes a novel approach to the problem of generating dynamic TV raster displays for real-time simulation (such as for visual flight simulation). In particular, the most time consuming part of generating such displays, the hidden surface elimination, is performed using many identical custom VLSI processors. Each processor is assigned a surface and for each pixel, all processorscompete to decide which object is visible. It is found that this approach leads to a practical system which is conceptually and practically simple, expandable, and reliable. 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
On the Weak mod m Representation of Boolean Functions
Authors: Vince Grolmusz
Venue:  (1995)

Let P be a polynomial over the ring of mod m integers. P weakly represents Boolean function f:{0,1}^n -< {0,1} if there is a subset S of {0,1, ... ,m-1} such that f(x)=0 if and only if P(x)is a member of S. The smallest degree of polynomials P weakly representing f is called the weak mod m degree of f. We give here an O(log n) lower bound for the weak degree of the generalized inner product function GIP of Babai, Nisan, and Szegedy. This is the first lower-bound result for the weak degree of a Boolean function that does not deteriorate if the number of prime divisors of m increases. In the second part of the paper, we give superpolynomial lower bounds for the number of monomials with nonzero coefficients in polynomials weakly representing the OR and the GIP composed with PARITY function.
Connected Components in O(lg3/2|V|) Parallel Time for the CREW PRAM
Authors: Donald B. Johnson, Panagiotis Metaxas
Venue:  (1991)

Computing the connected components of an undirected graph G = (V,E) on |V| = n vertices and |E| = m edges is a fundamental computational problem. The best known parallel algorithm for the CREW PRAM model runs on O(lg2n) time using n2/lg2n processors [CLC82,HCS79]. For the CRCW PRAM model in which concurrent writing is permitted, the best known algorithm runs in O(lg n) time using almost (n+m)/lg n processors [SV82,CV86,AS87]. Unfortunately, simulating this algorithm on the weaker CREW model increases its running time to O(lg2n) [CDR86, KR90,Vis83]. We present here an efficient and simple algorithm that runs in O(lg 3/2n) time using n+m CREW processors.
Wavelet-based neural net application for feature detection and classification
Authors: Ajay Verma, Akif Ibragimov, Satheesh Ramachandran
Venue: Neural, Parallel Scientific Computations (2003)

The paper presents an integrated methodology for detection and classification of corrosion that can be used to effectively characterize corrosion in critical areas such as lap joints for the aging aircraft. The approach involves a wavelet analysis based corrosion feature extraction method from the nondestructive inspection (NDI) data, and the extracted wavelet features are used by a neural net classification model for detection and classification of corrosion. From past experience, it has been seen that any given sensor is often insufficient for corrosion detection as each sensor has its own limitations. The experimental results from this project clearly validate that doing data fusion of multiple sensor signals improves the probability of detection and better assessment of corrosion damage. As part of our approach, we present a data standardization process that helps to bring data from different sensors to a common standard or scale, so that they can be compared directly before any data fusion. We use Ultrasonic and Eddy current sensor data for analysis, both of which are widely used methods of nondestructive inspection for corrosion detection. An efficient method for detecting "region of interest" or ROI for corrosion evaluation and classification is also presented.
Combining Computation with Geometry
Authors: Sheue Lien
Venue:  (1984)

This thesis seeks to establish mathematical principles and to provide efficient solutions to various time consuming operations in computer-aided geometric design. It contains a discussion of three major topics: (1) design validation by means of object interference detection, (2) object reconstruction through the union, intersection, and subtraction of two polyhedra, and (3) calculation of basic engineering properties such as volume, center of mass, or moments of inertia. Two criteria are presented for solving the problems of point-polygon enclosure and point polyhedron enclosure in object interference detection. An algorithm for efficient point-polyhedron-enclosure detection is presented. Singularities encountered in point-polyhedron-enclosure detection are categorized and simple methods for for resolving them are also included. A new scheme for representing solid objects, called skeletal polyhedron representation, is proposed. Also included are algorithms for performing set operations on polyhedra (or polygons) represented in skeletal polyhedron representation, algorithms for performing edge-edge intersection and face-face intersection in a set operation, and a perturbation method which can be used to resolve singularities for an easy execution of edge--edge intersection and face-face interaction. A symbolic method for calculating basic engineering properties (such as volume, center of mass, moments of inertia, and similar integral properties of geometrically complex solids) is proposed. The same method is generalized for computing the integral properties of a set combined polyhedron and for computing the integral properties of an arbitrary polyhedron inc m-dimensional (Rm) space. 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
Networked Cryptographic Devices Resilient to Capture
Authors: MacKenzie Philip, Reiter Michael K.
Venue:  (2001)

We present a simple technique by which a device that performs private key operations (signatures or decryptions) in networked applications, and whose local private key is activated with a password or PIN, can be immunized to offline dictionary attacks in case the device is captured. Our techniques do not assume tamper resistance of the device, but rather exploit the networked nature of the device, in that the device''s private key operations are performed using a simple interaction with a remote server. This server, however, is untrusted---its compromise does not reduce the security of the device''s private key unless the device is also captured---and need not have a prior relationship with the device. We further extend this approach with support for "key disabling", by which the rightful owner of a stolen device can disable the device''s private key even if the attacker already knows the user''s password.
Incremental Replication for Mobility Support in OBIWAN
Authors: Luís Veiga, Paulo Ferreira
Venue: Proceedings of the 22 nd International Conference on Distributed Computing Systems (ICDCS'02) (2002)

The need for sharing is well known in a large number of distributed collaborative applications. These applications are difficult to develop for wide area (possibly mobile) networks because of slow and unreliable connections.For this purpose, we developed a platform called OBIWAN 1 that: i) allows the application to decide, in runtime, the mechanism by which objects should be invoked, remote method invocation or invocation on a local replica, ii) allows incremental replication of large object graphs, iii) allows the creation of dynamic clusters of data, and iv) provides hooks for the application programmer to implement a set of application specific properties such as relaxed transactional support or updates dissemination.These mechanisms allow an application to deal with situations that frequently occur in a (mobile) wide-area network, such as disconnections and slow links: i) as long as objects needed by an application (or by an agent) are co-located, there is no need to be connected to the network, and ii) it is possible to replace, in runtime, remote by local invocations on replicas, thus improving the performance and adaptability of applications.The prototype is developed in Java, is very small and simple to use, the performance results are very encouraging, and existing applications can be easily modified to take advantage of OBIWAN.
A Semantic-Centric Approach to Information Visualization
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

A semantic-centric approach to information visualization is described in this paper. In contrast to the conventional document-centric approaches, the semantic-centric approach focuses on the intrinsic connectivity in an information space beyond the boundary of individual documents. The approach aims to visualize the profound interrelationships perceived by the scientific community through the literature. An application of this approach is demonstrated through an author co-citation analysis of the entire collection of the ACM Hypertext conference proceedings over the last decade. Sub-fields, or specialties, in the field of hypertext are visualized based on the results of a factor analysis of author co-citation patterns. Nine snapshots of annual author co-citation maps introduce a new way of knowledge discovering in an information space shaped by the contemporary literature.
On a fractional generalization of the free electron laser equation
Authors: R. K. Saxena, S. L. Kalla
Venue: Applied Mathematics and Computation (2003)

The following fractional generalization of the free electron laser equation is investigated: Dταh(τ)= λ ∫0τ tδh(τ-t)Φ(b; δ + 1; ivt)dt + µτγΦ (β,γ+1;ivτ), 0 ≤ τ ≤ 1, where β,γ,λ ∈ C; v,b, β ∈ R, α > 0, γ > -1 and δ > -1. A closed form solution is derived in terms of Kummer's function Φ(α, β; z) by the application of Riemann-Liouville fractional integration operators. Tau method approximation is used in the evaluation of the results in a suitable form for numerical computation. The results derived are of general character and provide extension of the work reported by Boyadjiev et al. and Al-Shammery et al. [Math. Comput. Model. 25 (1997) 1; Integral Transform. Spec. Funct. 9 (2000) 81; J. Fract. Cal. Appl. Anal. 2 (1999) 501].