ppxscal/embedding_network huggingface dataset:
A Four-Valued Logic B(4) of E(9) for Modeling Human Communication
Authors: Raiek Alnakari, David Rine
Venue: Proceedings of the 30th IEEE International Symposium on Multiple-Valued Logic (2000)

In this paper a four-valued logic on B(4) called Hyawic Form UniLogic. Examples of this UniLogic are given which model problems in the area of human interaction, dialog and communication, i.e. human speech. The four values, or states, are isolated, conflicting, co-existing and unifying, forming a square lattice of B(4), Post Algebra of order 2 with 4 elements, inside Post Algebra on E(9) of order 3 with 9 = 3*3 elements. This logic has been used to represent human speech problems and their solutions in college classrooms. This logic is used in different universities, countries and languages including France, Algeria, Egypt and USA. It is used for policy analysis and planning, as well as for academic research in inter-communications analysis. Software packages using this logic are available from the developer Dr. Raiek Alnakari.
Task Matching and Scheduling in Heterogeneous Systems Using Simulated Evolution
Authors: Hassan Barada, Sadiq M. Sait, Naved Baig
Venue: Proceedings of the 10th Heterogeneous Computing Workshop â"" HCW 2001 (Workshop 1) - Volume 2 (2001)

This paper describes and analyzes the application of a simulated evolution (SE) approach to the problem of matching and scheduling of coarse-grained tasks in a heterogeneous suite of machines. The various steps of the SE algorithm are first discussed. Goodness functionrequired by SE is designed and explained. Then experimental results applied on various types of workloads are analyzed. Workloads are characterized according to the connectivity, heterogeneity, and communication-to-cost ratio of the task graphs. The performance of SE is also compared with a genetic algorithm (GA) approach for the same problem with respect to the quality of solutions generated, and timing requirements of the algorithms.
A New Document Placement Scheme for Cooperative Caching on the Internet
Authors: Lakshmish Ramaswamy, Ling Liu
Venue: Proceedings of the 22 nd International Conference on Distributed Computing Systems (ICDCS'02) (2002)

Most existing work on cooperative caching has been focused on serving misses collaboratively. Very few have studied the effect of cooperation on document placementschemes and its potential enhancements on cache hit ratio and latency reduction. In this paper we propose a new document placement scheme called the EA Scheme, which takes into account the contentions at individual caches in order to limit the replication of documents within a cache group and increase document hit ratio. The main idea of this new scheme is to view the aggregate disk space of the cache group as a global resource of the group, and uses the concept of cache expiration age to measure the contention of individual caches. The decision of whether to cache a document at a proxy is made collectively among the caches that already have a copy of this document. The experiments show that the EA scheme yields higher hit rates and better response times compared to the existing document placement schemes used in most of the caching proxies.
Real-Time Databases: Issues and Applications (RTDB''96 Workshop Report)
Authors: Azer Bestavros, Kwei Lin, Sang Son
Venue:  (1996)

Abstract This report summarizes the technical presentations and discussions that took place during RTDB''96: the First International Workshop on Real-Time Databases, which was held on March 7 and 8, 1996 in Newport Beach, California. The main goals of this project were to (1) review recent advances in real-time database systems research, (2) to promote interaction among real-time database researchers and practitioners, and (3) to evaluate the maturity and directions of real-time database technology.
On the Use of COTS Microkernels for Dependable System
Authors: Jean-Charles Fabre
Venue: Proceedings of the The Fourth International Symposium on Autonomous Decentralized Systems (1999)

This paper addresses the problem of using COTS microkernels for the design and implementation of dependable systems. Although not designed to deal with faulty situation, their analysis in the presence of faults is of high interest since all upper layers rely on their correct behavior. Such an information can be used to design upper layers accordingly. However, as shown in many works, the results obtained using fault injection on COTS executives raise unacceptable situations for critical applications. The definition of fault containment mechanisms is mandatory to deal with such situations and make simpler the design of upper layer software. The approach proposed in this paper relies on the modeling of microkernel functionalities. Modeling is indeed possible because these functions are often simple. The implementation of efficient fault containment wrappers proposed here is based on a novel approach taking advantage of the notion of reflective components.
A General Framework for Computing Block Accesses
Authors: Bradley T. Vander Zanden, Howard M. Taylor, Dina Bitton
Venue:  (1985)

A physical database system design should take account of skewed block access distributions, nonuniformly distributed attribute domains, and dependent attributes. In this paper we derive general formulas for the number of blocks accessed under these assumptions by considering a class of related occupancy problems. We then proceed to develop robust and accurate approximations for these formulas. We investigate three clases of approximation methods, respectively based on generating functions, Taylor series expansions, and majorization. These approximations are as simple to use and far more accurate than the cost estimate formulas generated by making independence and uniformity assumptions.
The Rectangle of Influence Drawability Problem
Authors: G. Liotta, A. L Meijer, S. H. Whitesides
Venue:  (1996)

A proximity drawing of a graph is a straight-line drawing where adjacent vertices are represented by points that are deemed to be close according to some proximity measure. A rectangle of influence drawing is a proximity drawing where the measure is based on the concept of rectangle of influence. Given two points u and v, the rectangle of influence of u and v is the axis-aligned rectangle having u and v at opposite corners. The rectangle of influence drawing of a graph G is a proximity drawing of G such that (i) for each pair of adjacent vertices u,v of G, the rectangle of influence of the points representing u and v is empty (i.e. contains no point representing a vertex distinct from u and v), and (ii) for each pair of non-adjacent vertices u,v of G, the rectangle of influence of the points representing u and v is not empty. Two different representation models are possible depending on whether the rectangle of influence is an open or a closed set. In this paper we study the drawability of several classes of graphs with respect to both the closed and the open model. We characterize, for each class and model, which graphs have a rectangle of influence drawing. For each class we show that testing whether a graph G has a rectangle of influence drawing can be done in O(n) time, where n is the number of vertices of G. Furthermore, if the test for G is affirmative, we show how to construct a rectangle of influence drawing of G. All the drawing algorithms can be implemented so that they (1) produce drawings with all vertices placed at intersection points of an integer grid of size O($n^2$), (2) perform arithmetic operations on integers only, and (3) run in O(n) time, where n is the number of vertices of the input graph.
Induced burstiness in generalized processor sharing queues with long-tailed traffic flows
Authors: Simon C. Borst, Onno J. Boxma, P. R. Jelenkovic
Venue:  (2000)

We analyze the queueing behavior of long-tailed traffic flows under the Generalized Processor Sharing (GPS) discipline. GPS-based scheduling algorithms, such as Weighted Fair Queueing, play a major role in achieving differentiated quality-of-service in integrated-services networks. We prove that, in certain scenarios, a flow may be strongly affected by the activity of `heavier''-tailed flows, and may inherit their traffic characteristics, causing induced burstiness. This phenomenon contrasts with previous results which show that, under certain conditions, an individual flow with long-tailed traffic characteristics is effectively served at a constant rate. In particular, the flow is then essentially immune from excessive activity of flows with `heavier''-tailed traffic characteristics. The sharp dichotomy in qualitative behavior illustrates the crucial importance of the weight parameters in protecting individual flows.
Note on "Comparison of model selection for regression" by Vladimir Cherkassky and Yunqian Ma
Authors: Trevor Hastie, Rob Tibshirani, Jerome Friedman
Venue: Neural Computation (2003)

While Cherkassky and Ma (2003) raise some interesting issues in comparing techniques for model selection, their article appears to be written largely in protest of comparisons made in our book, Elements of Statistical Learning (2001). Cherkassky and Ma feel that we falsely represented the structural risk minimization (SRM) method, which they defend strongly here.In a two-page section of our book (pp. 212-213), we made an honest attempt to compare the SRM method with two related techniques, Aikaike information criterion (AIC) and Bayesian information criterion (BIC). Apparently, we did not apply SRM in the optimal way. We are also accused of using contrived examples, designed to make SRM look bad.Alas, we did introduce some careless errors in our original simulation-- errors that were corrected in the second and subsequent printings. Some of these errors were pointed out to us by Cherkassky and Ma (we supplied them with our source code), and as a result we replaced the assessment "SRM performs poorly overall" with a more moderate "the performance of SRM is mixed" (p. 212). These and other corrections can be seen in the errata section on-line at http://www-stat.stanford.edu/ElemStatLearn.
An omega-complete equational specification of interleaving
Authors: Wan J. Fokkink, S. P. Luttik
Venue:  (2000)

We consider the process theory $\PA$ that includes an operation for parallel composition, based on the interleaving paradigm. We prove that the standard set of axioms of $\PA$ is not $\omega$-complete by providing a set of axioms that are valid in $\PA$, but not derivable from the standard ones. We prove that extending $\PA$ with this set yields an $\omega$-complete specification, which is finite in a setting with finitely many actions.
Numerical Conformal Mapping Using Cross-ratios and Delaunay Triangulation
Authors: Tobin Driscoll, Stephen A. Vavasis
Venue:  (1996)

We propose a new algorithm for computing the Riemann mapping of the unit disk to a polygon, also known as the Schwarz-Christoffel transformation. The new algorithm, CRDT, is based on cross-ratios of the prevertices, and also on cross-ratios of quadrilaterals in a Delaunay triangulation of the polygon. The CRDT algorithm produces an accurate representation of the Riemann mapping even in the presence of arbitrary long, thin regions in the polygon, unlike any previous conformal mapping algorithm. We believe that CRDT can never fail to converge to the correct Riemann mapping, but the correctness and convergence proof depend on conjectures that we have so far not been able to prove. We demonstrate convergence with computational experiments. The Riemann mapping has applications to problems in two-dimensional potential theory and to finite-difference mesh generation. We use CRDT to produce a mapping and solve a boundary value problem on long, thin regions for which no other algorithm can solve these problems. Keywords: numerical conformal mapping, Schwarz-Christoffel mapping, cross-ratios, Delaunay triangulation, crowding AMS subject classifications: 30C30, 65E05
Further considerations on residual-free bubbles for advective-diffusive equations
Authors: Leopoldo P. Franca, Franco Brezzi, Alessandro Russo
Venue:  (1997)

We further consider the Galerkin method for advective-diffusive equations in two-dimensions. The finite dimensional space employed is of piecewise polynomials enriched with residual-free bubbles (RFB). We show that, in general, this method does not coincide with the SUPG method, unless the piecewise polynomials are spanned by linear functions. Furthermore a simple stability analysis argument displays the effect of the RFB on the reduced space of piecewise polynomials, which is not equivalent to streamline diffusion for bilinears, in some situations. EMAIL:: ian@microian.ian.pv.cnr.it
Package Routing in Transportation Networks with Fixed Vehicle Schedules: Formulation, Complexity Results and Approximation Algorithms
Authors: Lloyd Greenwald, Thomas Dean
Venue:  (1992)

We consider a special case of a general problem involving the deployment of vehicles to transport packages in transportation networks. In this special case, the schedules of the vehicles are fixed and packages are routed by transferring them between vehicles as these vehicles make stops according to their fixed schedules. We show that this problem is hard and explore approximation algorithms for its solution. In particular, we cast this problem as a multicommodity flow problem with a mixed integerlinear program formulation. We then apply combinatorial optimization techniques based on solving the relaxed linear programming formulation of the problem to obtain provable feasibility and expected performance guarantees, where performance is measured in terms of the sum of the time in transit over all packages. We investigate the sensitivity of the performance guarantees to certain scaling factors and other limitations of this technique.
A Multimedia Interactive Environment Using Program Archetypes: Divide-and-Conquer
Authors: Paul Ainsworth, Svetlana Kryukova
Venue:  (1993)

As networks and distributed systems that can exploit parallel computing become more widespread, the need for ways to teach parallel programming effectively grows as well. Even though many colleges and universities provide courses on parallel programming [1], most of those courses are reserved for graduate students and advanced undergraduates. There is a demand for ways to teach fundamental parallel programming concepts to people with just a working knowledge of programming. By using the idea of a software archetype, and providing a learning environment that teaches both concept and coding, we hope to satisfy this need. This paper presents an overview of the multimedia approach we took in teaching parallel programming and offers Divide-and-Conquer as an example of its use.
Sequential Estimation Techniques for Quasi-Newton Algorithms
Authors: Stephen W Thomas
Venue:  (1975)

Let $F$ be a mapping from real $n$-dimensional Euclidean space into itself. In terms of solving for a zero of $F$, the quasi-Newton algorithms are based on the generalized Newton iteration $x_{k+1} = x_{k} B_{k}^{-1}F(x_{k})$, where $\{B_{k}\}$ is a sequence of nonsingular matrices. In this thesis some geometrical sequential estimation techniques are applied to the calculation of a $B_{k}$ as an estimate for the Jacobian matrix $F''(x_{k})$. The resulting estimators manifest themselves as either rank-one or rank-two, symmetric updates for $B_{k}$, together with an update for a matrix which is descriptive of the error $E_{k} = B_{k} F''(x_{k})$. These updates are in fact shown to produce optimal estimates in the sense that they minimize the set size of a certain bound for the error matrix $E_{k}$. It is shown that the use of the new updates in conjunction with the generalized Newton iteration produces locally and Q-superlinearly convergent algorithms. Moreover, under the requirement that the steps taken by the algorithm satisfy a uniform linear independence condition, it is shown that the R-order of convergence associated with the symmetric update is at least as large as the positive root of $t^{n+1} t^{n} 1 = 0$. A similar but somewhat lower rate of convergence bound is proved for the rank-one update. The symmetric update is implemented in an algorithm for unconstrained optimization which employs Powell''s dog-leg step direction/length strategy as a globalization technique. Analysis is presented which, under mild conditions on the function to be minimized, shows that the algorithm is globally and Q-superlinearly convergent. The results of some numerical experiments are presented which show that the algorithm''s performance compares favorably with Powell''s very successful MINFA. 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
Connection Scheduling in Web Servers
Authors: Mark Crovella, Robert Frangioso, Mor Harchol-Balter
Venue:  (1999)

Abstract Under high loads, a Web server may be servicing many hundreds of connections concurrently. In traditional Web servers, the question of the order in which concurrent connections are serviced has been left to the operating system. In this paper we ask whether servers might provide better service by using non-traditional service ordering. In particular, for the case when a Web server is serving static files, we examine the costs and benefits of a policy that gives preferential service to short connections. We start by assessing the scheduling behavior of a commonly used server (Apache running on Linux) with respect to connection size and show that it does not appear to provide preferential service to short connections. We then examine the potential performance improvements of a policy that does favor short connections (shortest-connection-first). We show that mean response time can be improved by factors of four or five under shortest-connection-first, as compared to an (Apache-like) size-independent policy. Finally we assess the costs of shortest-connection-first scheduling in terms of unfairness (i.e., the degree to which long connections suffer). We show that under shortest-connection-first scheduling, long connections pay very little penalty. This surprising result can be understood as a consequence of heavy-tailed Web server workloads, in which most connections are small, but most server load is due to the few large connections. We support this explanation using analysis.
The EELRU adaptive replacement algorithm
Authors: Yannis Smaragdakis, Scott Kaplan, Paul Wilson
Venue: Performance Evaluation (2003)

The wide performance gap between processors and disks ensures that effective page replacement remains an important consideration in modern systems. This paper presents early eviction LRU (EELRU), an adaptive replacement algorithm. EELRU uses aggregate recency information to recognize the reference behavior of a workload and to adjust its speed of adaptation. An on-line cost/benefit analysis guides replacement decisions. This analysis is based on the LRU stack model (LRUSM) of program behavior. Essentially, EELRU is an on-line approximation of an optimal algorithm for the LRUSM. We prove that EELRU offers strong theoretical guarantees of performance relative to the LRU replacement algorithm. EELRU can never be more than a factor of 3 worse than LRU, while in a common best case it can be better than LRU by a large factor (proportional to the number of pages in memory).The goal of EELRU is to provide a simple replacement algorithm that adapts to reference patterns at all scales. Thus, EELRU should perform well for a wider range of programs and memory sizes than other algorithms. Practical experiments validate this claim. For a large number of programs and wide ranges of memory sizes, we show that EELRU outperforms LRU, typically reducing misses by 10-30%, and occasionally by much more--sometimes by a factor of 2-10. It rarely performs worse than LRU, and then only by a small amount.
Optimizing stable in-place merging
Authors: Jingchao Chen
Venue: Theoretical Computer Science (2003)

In 2000, Geffert et al. (Theoret. Comput. Sci. 237 (2000) 159) presented an asymptotically efficient algorithm for stable merging in constant extra space. The algorithm requires at most m1(t + 1) + m2/2t + o(m1) comparisons (t = ⌊log2(m2/m1)⌋) and 5m2 + 12m1 + o(m1) moves, where m1 and m2 are the sizes of two ordered sublists to be merged, and m1 ≤ m2. This paper optimizes the algorithm. The optimized algorithm is simpler than their algorithm, and makes at most m1(t + 1) + m2/2t + o(m1 + m2) comparisons and 6m2 + 7m1 + o(m1 + m2) moves.
An Algorithm for Processing Program Transformations
Authors: Sofoklis G. Efremidis, David Gries
Venue:  (1993)

An algorithm for processing program transformations as described by the transform construct is presented. The algorithm constructs a coordinate transformation of an abstract program based on a set of transforms and transform directives applied to it.
Online discussion boards: impacting the learning experience
Authors: Sandra Barker
Venue: Proceedings of the fifth Australasian conference on Computing education - Volume 20 (2003)

The availability of technology has seen the development of online asynchronous discussion boards for use in teaching and learning. This paper explores the use of this medium within a second year undergraduate business course at the University of South Australia to supplement traditional delivery methods as well as showing how this medium can be used to enhance the development of communication, critical analysis, problem-solving and collaboration skills.
On-Line Recovery for Rediscovered Software Problems
Authors: Inhwan Lee, Randy McRee, Wendy Bartlett
Venue: Proceedings of the 2nd International Computer Performance and Dependability Symposium (IPDS '96) (1996)

This paper discusses a method that can allow a system to avoid or recover from the exercise of certain known faults at runtime and thus make certain software upgrades unnecessary. The method uses the knowledge of the characteristic symptoms of a software fault and the appropriate recovery action for the fault to detect and recover from the future exercise of the fault. An analysis of field data shows that the method is applicable to about 25% of faults and there is a potential for this number to go up. Using the method can not only improve the availability of user applications, but can also reduce the number of rediscovered problems and hence reduce the resources required for software service.
A Deductive Solution for Plan Generation
Authors: Wolfgang Bibel
Venue:  (1985)

A new deductive method for solving robot problems is presented in this paper. The descriptions of initial and goal situations are given by logical formulas. The primitive actions are described by rules, i.e., logical formulas as well. Altogether this results in a problem description like in program synthesis or logic programming. A solution is generated by a proof of this description as usual in logic programming except that here proofs have to be strictly linear. This restriction is the clue of our solution; it can be easily added as an option to any theorem prover such as one based on the connection method used hereafter. In fact this restriction speeds up the proof search considerably. At the same time our approach offers an elegant solution of the frame problem.