ppxscal/embedding_network huggingface dataset:
A comparitive performance analysis of reliable group rekey transport protocols for secure multicast
Authors: Sanjeev Setia, Sencun Zhu, Sushil Jajodia
Venue: Performance Evaluation (2002)

In this paper, we present a new scalable and reliable key distribution protocol for group key management schemes that use logical key hierarchies (LKH) for scalable group rekeying. Our protocol called WKA-BKR is based upon two ideas--weighted key assignment and batched key retransmission--both of which exploit the special properties of LKH and the group rekey transport payload to reduce the bandwidth overhead of the reliable key delivery protocol. Using both analytic modeling and simulation, we compare the performance of WKA-BKR with that of other rekey transport protocols, including a recently proposed protocol based on proactive FEC. Our results show that for most network loss scenarios, the bandwidth used by WKA-BKR is lower than that of the other protocols.
Arbitration (or How to Merge Knowledge Bases)
Authors: Paolo Liberatore, Marco Schaerf
Venue: IEEE Transactions on Knowledge and Data Engineering (1998)

Knowledge-based systems must be able to "intelligently" manage a large amount of information coming from different sources and at different moments in time. Intelligent systems must be able to cope with a changing world by adopting a "principled" strategy. Many formalisms have been put forward in the artificial intelligence (AI) and database (DB) literature to address this problem. Among them, belief revision is one of the most successful frameworks to deal with dynamically changing worlds. Formal properties of belief revision have been investigated by Alchourron, Gärdenfors, and Makinson, who put forward a set of postulates stating the properties that a belief revision operator should satisfy. Among these properties, a basic assumption of revision is that the new piece of information is totally reliable and, therefore, must be in the revised knowledge base. Different principles must be applied when there are two different sources of information and each one has a different view of the situation¿the two views contradicting each other. If we do not have any reason to consider any of the sources completely unreliable, the best we can do is to "merge" the two views in a new and consistent one, trying to preserve as much information as possible. We call this merging process arbitration. In this paper, we investigate the properties that any arbitration operator should satisfy. In the style of Alchourron, Gärdenfors, and Makinson we propose a set of postulates, analyze their properties, and propose actual operators for arbitration.
A Global Solution to Sparse Correspondence Problems
Authors: João Maciel, João P. Costeira
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2003)

We propose a new methodology for reliably solving the correspondence problem between sparse sets of points of two or more images. This is a key step in most problems of computer vision and, so far, no general method exists to solve it. Our methodology is able to handle most of the commonly used assumptions in a unique formulation, independent of the domain of application and type of features. It performs correspondence and outlier rejection in a single step and achieves global optimality with feasible computation. Feature selection and correspondence are first formulated as an integer optimization problem. This is a blunt formulation, which considers the whole combinatorial space of possible point selections and correspondences. To find its global optimal solution, we build a concave objective function and relax the search domain into its convex-hull. The special structure of this extended problem assures its equivalence to the original one, but it can be optimally solved by efficient algorithms that avoid combinatorial search. This methodology can use any criterion provided it can be translated into cost functions with continuous second derivatives.
The 82460GX Sever/Workstation Chip Set
Authors: Eric Dahlen, Jennifer Gustin, Susan Meredith, Doug Moran
Venue: IEEE Micro (2000)

This article provides an introduction to the memory, I/O, and graphics subsystems of Intel's Itanium processor chip set and discusses several aspects of the processor bus.
Investigating the Influence of Formal Methods
Authors: Shari Lawrence Pfleeger, Les Hatton
Venue: Computer (1997)

Formal methods promise much, but can they deliver? In this project, results are inconclusive, but careful data gathering and analysis helped establish influences on product quality. Practitioners and researchers continue to seek methods and tools for improving software development processes and products. Candidate technologies promise increased productivity, better quality, lower cost, or enhanced customer satisfaction. But we must test these methods and tools empirically and rigorously to determine any significant, quantifiable improvement. We tend to consider evaluation only after using the technology, which makes careful, quantitative analysis difficult if not impossible. However, when an evaluation is designed as part of overall project planning, and then carried out as software development progresses, the result can be a rich record of a tool's or technique's effectiveness. In this study, we investigated the effects of using formal methods to develop an air-traffic-control information system. Because we are studying one project in isolation, we cannot draw conclusions about the suitability of formal methods for all projects. As we describe in the sidebar "Can Formal Methods Always Deliver?" the jury is still out on when and whether formal methods improve products. Nevertheless, the lessons we learned are instructive, not only in showing how formal methods influenced code quality on this project, but also in highlighting the limitations of retrospective studies and their use in planning follow-up investigations. We describe what we did, as well as what we could have done had the study been carried out as the software system was being developed and tested. We also show how this preliminary investigation helps to suggest hypotheses for further studies. Thus, the lessons we learned can be applied not only to gauge the effects of formal methods but also in planning similar studies of other techniques and tools. The procedure we used was not predetermined; the results of one analysis step largely determined where we went next. Indeed, research often involves following one trail and then another, uncovering relationships and unearthing facts, until the picture begins to make sense. However, we did learn many specific lessons, which we hope will enrich future investigations.
Computer Engineering 30 Years After the IBM Model 91
Authors: Michael J. Flynn
Venue: Computer (1998)

Often in the hurry to create the future, computer engineers ignore lessons from past projects. One project that offers interesting insights, the IBM System/360 Model 91, recently celebrated the 30th anniversary of its first shipment. The largest member of the series based on IBM's most enduring and influential computer architecture, this machine owed much to its predecessors. Together, these machines show us what the state of the art in computer processors was like in the 1960s and illustrate how far computer engineering has come in 30 years. By looking back, can computer engineers learn what needs to change for the future? In the future, every computer engineer should use existing publications and source material. Perhaps most importantly, computer engineers need to acknowledge the use of prior references. The author thinks it depressing to see engineers waste work rediscovering an old idea. He finds it even more discouraging to see them use old ideas without acknowledgment when the idea's source is obvious.
A Fast Handoff Management Scheme in ATM-Based Personal Communication Networks
Authors: Seung Joon Lee, Dan Keun Sung
Venue: Wireless Personal Communications: An International Journal (1999)

Future wireless personal communication networks will likely have infrastructures based on asynchronous transfer mode (ATM) networks. It is a challenge to support seamless, fast handoffs in such an environment. We propose a fast handoff management scheme using permanent virtual connections (PVCs) reserved between neighboring base stations (BSs). In the proposed scheme, the handoff can be quickly performed by rerouting the communication path via the PVCs. Handoff calls are distributively controlled only by the corresponding BSs without the involvement of any ATM switches. ATM cell sequence integrity during handoff can be maintained by the BSs. In order to dimension the PVC, we analytically derive the probability of handoff blocking due to the lack of PVCs. We give some numerical examples of PVC dimensioning. The proposed scheme can be utilized in the future IMT-2000 networks accommodating various narrowband services in the range of several kbps to several hundreds kbps.
Concurrent Processing of Linearly Ordered Data Structures on Hypercube Multicomputers
Authors: J. Ghosh, S. K. Das, A. John
Venue: IEEE Transactions on Parallel and Distributed Systems (1994)

The paper presents a simple and effective method for the concurrent manipulation oflinearly ordered data structures on hypercube systems. The method Is based on theexistence of an augmented binomial search tree, called the pruned binomial tree, rootedat any arbitrary processor node of the hypercube such that; every edge of the treecorresponds to a direct link between a pair of hypercube nodes; and the tree spans anyarbitrary sequence of n consecutive nodes containing the root, using a fanout of at most[log/sub 2/ n] and a depth of at most [log/sub 2/ n]+1. Search trees spanningnonoverlapping processor lists are formed using only local information, and can be usedconcurrently without contention problems. Thus, they can be used for performingoperations such as broadcast and merge simultaneously on sets with nonuniform sizes.Extensions of the tree to k-ary n-cubes and faulty hypercubes are presented.Applications of this concurrent data structure to low- and intermediate-level imageprocessing algorithms, and for dictionary operations involving multiple keys, are alsooutlined.
Adaptive Core Selection and Migration Method for Multicast Routing in Mobile Ad Hoc Networks
Authors: S. K. S. Gupta, P. K. Srimani
Venue: IEEE Transactions on Parallel and Distributed Systems (2003)

Several multicast protocols such as Protocol Independent Multicast (PIM) and Core-Based Trees (CBT) use the notion of group-shared trees. The reason is that construction of minimal-cost tree spanning all members of the multicast group is expensive, hence these protocols use a core-based group-shared tree to distribute packets from all the sources. A core-based tree is a shortest-path tree rooted at some core node. The core node is also referred to as a center node or a rendezvous point. Core nodes may be chosen from some preselected set of nodes or some heuristics may be employed to select core nodes. In this paper, we present distributed core selection and migration protocols for mobile ad hoc networks with dynamically changing network topology. Most protocols for core selection in static networks are not suitable for ad hoc networks, since these algorithms depend on knowledge of entire network topology, which is not available or is too expensive to maintain in an ad hoc network with dynamic topology. The proposed core location method is based on the notion of median node of the current multicast tree instead of the median node of the entire network. The rationale is that the mobile ad hoc network graphs are in general sparse and, hence, the multicast tree is a good approximation of the entire network for the current purpose. Our adaptive distributed core selection and migration method uses the fact that the median of a tree is equivalent to the centroid of that tree. The significance of this observation is due to the fact that the computation of a tree's centroids does not require any distance information. Mobile ad hoc networks have limited bandwidth which needs to be conserved. Hence, we use the cost of multicast tree as the sum of weights of all the links in the tree, which signifies the total bandwidth consumed for multicasting a packet. We compare the cost of shortest-path tree rooted at the tree median, Cost_TM, with the cost of shortest-path tree rooted at the median of the graph, Cost_GM, which requires complete topology information to compute. A network graph model for generating random ad hoc mobile networks is developed to perform this comparison. The simulation results show that for large size networks, the ratio Cost_TM/Cost_GM lies between 0.8 to 1.2 for different multicast groups. Further, as the size of the multicast group increases the ratio approaches 1.
Genome Sequence Assembly: Algorithms and Issues
Authors: Mihai Pop, Steven L. Salzberg, Martin Shumway
Venue: Computer (2002)

Ultimately, genome sequencing seeks to provide an organism's complete DNA sequence. Automation of DNA sequencing allowed scientists to decode entire genomes and gave birth to genomics, the analytic and comparative study of genomes. Although genomes can include billions of nucleotides, the chemical reactions researchers use to decode the DNA are accurate for only about 600 to 700 nucleotides at a time.The DNA reads that sequencing produces must then be assembled into a complete picture of the genome. Errors and certain DNA characteristics complicate assembly. Resolving these problemsentails an additional and costly finishing phase that involves extensive human intervention. Assembly programs can dramatically reduce this cost by taking into account additional informationobtained during finishing. Algorithms that can assemble millions of DNA fragments into gene sequences underlie the current revolution in biotechnology, helping researchers build the growingdatabase of complete genomes.
On Computing the Points and Weights for Gauss-Legendre Quadrature
Authors: Paul N. Swarztrauber
Venue: SIAM Journal on Scientific Computing (2002)

Three methods are compared for computing n points xi and weights w(xi) for Gauss--Legendre quadrature. The eigensystem method computes the points as the eigenvalues of a symmetric tridiagonal matrix, and the weights are computed from its eigenvectors. The resulting error is O(n) for the points and $O(n^2)$ for the weights. Using an inverse Taylor series computation for the points, Yakimiw [J. Comput. Phys., 129 (1996), pp. 406--430] reduced the point error growth to O(1). He also reduced the error in the weights to O(n) and obtained uniform pointwise relative accuracy. However, the points xi cluster quadratically near the end points $x = \pm 1$, where for some n = nmax they coalesce or even exchange to within machine accuracy, and computation fails. Although this has not been a problem in the past, it could soon become so because weather models are now approaching resolutions with n > 1000. Here we compare these methods to the Fourier--Newton method, which consists of Newton's method for computing the transformed points $\theta_i = \arccos x_i$ as the zeros of the Fourier representations of the Legendre polynomials $P_n(\theta)$. The $\theta_i$ are near equally spaced, particularly in the neighborhood of x = 0. For a fixed arithmetic precision, this extends the range of computable points and weights to $n=n_{max}^2$, where nmax is the limit for methods based on xi. Both the accuracy and speed of the three methods are tabulated.
Mobile and Personal Communications in the 60 GHz Band: A Survey
Authors: Filippo Giannetti, Marco Luise, Ruggero Reggiannini
Venue: Wireless Personal Communications: An International Journal (1999)

This paper intends to present a summary of the technical issues arising in the exploitation of the 60 GHz mm-wave band for mobile and personal communications. The most significant applications proposed so far are surveyed, with particular emphasis placed on recent experimentation about millimeter-wave propagation for road/railway transportation as well as indoor scenarios. As a case study, the capacity of a (micro-)cellular Code Division Multiple Access (CDMA) network in the 60-GHz band is also evaluated in detail.
On the stability number of the edge intersection of two graphs
Authors: Claudio Arbib, Alberto Caprara
Venue: Information Processing Letters (2002)

Let G be the graph obtained as the edge intersection of two graphs G1, G2 on the same vertex set V. We show that if at least one of G1, G2 is perfect, then α(G) ≤ α(G1) . α(G2), where α0 is the cardinality of the largest stable set. Moreover, for general G1 and G1, we show that α(G) ≤ R(α(G1) + 1, α(G2) + 1) - 1, where R(k,l) is the Ramsey number.
Structuring Knowledge In Vague Domains
Authors: Ron Sun
Venue: IEEE Transactions on Knowledge and Data Engineering (1995)

In this paper, we propose a model for structuring knowledge in vague and continuous domains where similarity plays a role in coming up with plausible inferences. The model consists of two levels, one of which is an inference network with nodes representing concepts and links representing rules connecting concepts, and the other is a microfeature-based replica of the first level. Based on the interaction between the concept nodes and microfeature nodes in the model, inferences are facilitated and knowledge not explicitly encoded in a system can be deduced via mixed similarity matching and rule application. The model is able to take account of many important desiderata of plausible reasoning and produces sensible conclusions accordingly. Examples will be presented to illustrate the utility of the model in structuring knowledge to enable useful inferences to be carried out in several domains.
Interference suppression in multiuser DS-CDMA communication systems using RMGS algorithm
Authors: Abdullah I. Hassan, D. K. Mehra
Venue: Signal Processing (2002)

A direct sequence code division multiple access (DS-CDMA) adaptive receiver for suppressing multiple access interference (MAI), based on the minimum mean squared error (MMSE) criterion, is introduced using the recursive modified Gram-Schmidt (RMGS) algorithm. It is shown, by simulation, that the RMGS algorithm is stable unlike the RLS algorithm, while requiring similar or less number of operations as compared to RLS and QRD-LS algorithms. Parallel implementation of the RMGS algorithm using systolic arrays, which will reduce its complexity to O(N) using N-parallel processors, is also described. The performance of the RMGS algorithm has been evaluated and compared to the normalized LMS and RLS algorithms.
Creating Architectures with Building Blocks
Authors: Frank J. van der Linden, Jürgen K. Müller
Venue: IEEE Software (1995)

At Philips Communications Industry (PKI), we develop embedded telecommunication-infrastructure systems. Because we must deliver each product in site-specific configurations -- of which there are many -- and because the development of such systems is a major investment, we must create a product family rather than a single product. We organize system construction according to three design dimensions covered by the system architecture: structure, aspects, and behavior.Of the three dimensions, we consider structure to be the most important. In this dimension, reducing complexity is our main concern. We thus organize system functionality into four layers, or subsystems. These subsystems are composed of software modules -- 'building blocks' -- which are the basic software entities in the system architecture.The Building-Block Method is an architectural method. It does not prescribe the precise method you should use to develop the building blocks. You can use different methods within one system according to the specific requirements for each building block. You can also use formal or informal specifications for building blocks, depending upon your application domain.
General Properties and Termination Conditions for Soft Constraint Propagation
Authors: S. Bistarelli, R. Gennari, F. Rossi
Venue: Constraints (2003)

Soft constraints based on semirings are a generalization of classical constraints, where tuples of variables' values in each soft constraint are associated to elements from an algebraic structure called semiring. This framework is able to express, for example, fuzzy, classical, weighted, valued and over-constrained constraint problems.Classical constraint propagation has been extended and adapted to soft constraints by defining a schema for soft constraint propagation &lsqb;8&rsqb;. On the other hand, in &lsqb;1&ndash;3&rsqb; it has been proven that most of the well known constraint propagation algorithms for classical constraints can be cast within a single schema.In this paper we combine these two schemas and we provide a more general framework where the schema of &lsqb;3&rsqb; can be used for soft constraints. In doing so, we generalize the concept of soft constraint propagation, and we provide new sufficient and independent conditions for its termination.
Laplacian spectra and invariants of graphs
Authors: Yasuo Teranishi
Venue: Discrete Mathematics (2002)

For a connected graph G of order n ≥ 2 with positive Laplacian eigenvalues λ2,...,λn, let b(G) = n-1 1/λ2 + ... + 1/λn. In this note we derive bounds on some graph invariants (edge-density in cuts, isoperimetric number, mean distance, edge-forwarding index, edge connectivity, etc) in terms of b(G).
Supplemental Cryptographic Hardware for Smart Cards
Authors: Elena Trichina, Marco Bucci, Domenico De Seta, Raimondo Luzzi
Venue: IEEE Micro (2001)

Software alone cannot satisfy all smart card requirements. Manufacturers must offer additional functions in hardware. The authors describe true random-number generators and an Advanced Encryption Standard computation unit; two different special-purpose hardware blocks that can be integrated on the silicon substrate along with the usual functional units of a smart card microcontroller.
Effect of stresses in electronic properties of chromium disilicide
Authors: V. L. Shaposhnikov, A. V. Krivosheeva, A. E. Krivosheev, A. B. Filonov, V. E. Borisenko
Venue: Microelectronic Engineering (2002)

A detailed theoretical study of electronic properties of chromium disilicide CrSi2 under isotropic and anisotropic pressure has been performed by means of linearized augmented plane wave method. It has been found that in case of isotropic deformation the indirect and first direct gaps decrease linearly with the rise of the pressure but with different rates. A similar behavior was observed for uniaxial stress, while this dependence is more complicated and not linear. When the crystal structure is being 106% stretched, chromium disilicide becomes a direct-gap semiconductor with energy gap of about 0.31 eV.
Christopher Strachey: Recollections of His Influence
Authors: Mike Gordon
Venue: Higher-Order and Symbolic Computation (2000)

My early research was inspired by the mathematical semantics of Scott and Strachey. Two such topics, recounted in this paper, were the fixed-point analysis of pointer loops and the expressibility of a style of functional programming introduced by Barron and Strachey.