ppxscal/embedding_network huggingface dataset:
Existence of Perfect 3-Deletion-CorrectingCodes
Authors: A. Mahmoodi
Venue: Designs, Codes and Cryptography (1998)

Bours [4] recently showed some constructions for perfect 2 and 3-deletion-correcting codes from combinatorial designs. He settled existence of perfect 2-deletion-correcting codes with words of length 4. However, the existence of perfect 3-deletion-correcting codes with words of length 5, or T^*(2, 5, v), remained unsettled for v &equiv; 7, 8 (mod 10) and v = 13, 14, 15, 16. In this paper we provide new constructions for these codes from combinatorial designs, and show that a T^*(2, 5, v) exists for all v.
Constant Time Algorithms for Computational Geometry on the Reconfigurable Mesh
Authors: Ju-wook Jang, Madhusudan Nigam, Viktor K. Prasanna, Sartaj Sahni
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

The reconfigurable mesh consists of an array of processors interconnected by a reconfigurable bus system. The bus system can be used to dynamically obtain various interconnection patterns among the processors. Recently, this model has attracted a lot of attention. In this paper, we show O(1) time solutions to the following computational geometry problems on the reconfigurable mesh: all-pairs nearest neighbors, convex hull, triangulation, two-dimensional maxima, two-set dominance counting, and smallest enclosing box. All these solutions accept N planar points as input and employ an N×N reconfigurable mesh. The basic scheme employed in our implementations is to recursively find an O(1) time solution. The number of recursion levels and the size of the subproblems at each level of recursion are optimized such that the problem decomposition and the solution to the problem can be obtained in constant time. As a result, we have developed some efficient merge techniques to combine the solutions for subproblems on the reconfigurable mesh. These techniques exploit reconfigurability in nontrivial ways leading to constant time solutions using optimal size of the mesh.
Optimally adaptive, minimum-distance, circuit-switched routing in hypercubes
Authors: Ausif Mahmood, Donald J. Lynch, Roger B. Shaffer
Venue: ACM Transactions on Computer Systems (TOCS) (1997)

In circuit-switched routing, the path between a source and its destination is established by incrementally reserving all required links before the data transmission can begin. If the routing algorithm is not carefully designed, deadlocks can occur in reserving these links. Deadlock-free algorithms based on dimension-ordered routing, such as the E-cube, exist. However, E-cube does not provide any flexibility in choosing a path from a source to its destination and can thus result in long latencies under heavy or uneven traffic. Adaptive, minimum-distance routing algorithms, such as the Turn Model and the UP Preference algorithms, have previously been reported. In this article, we present a new class of adaptive, provably deadlock-free, minimum-distance routing algorithms. We prove that the algorithms developed here are optimally adaptive in the sense that any further flexibility in communication will result in deadlock. We show that the Turn Model is actually a member of our new class of algorithms that does not perform as well as other algorithms within the new class. It creates artificial hotspots in routing the traffic and allows fewer total paths. We present an analytical comparison of the flexibility and balance in routing provided by various algorithms and a comparison based on uniform and nonuniform traffic simulations. The Extended UP Preference algorithm developed in this article is shown to have improved performance with respect to existing algorithms. The methodology and the algorithms developed here can be used to develop routing for other schemes such as wormhole routing, and for other recursively defined networks such as k-ary n-cubes.
An experimental study of factors important in document ranking
Authors: Donna Williamson Harman
Venue: Proceedings of the 9th annual international ACM SIGIR conference on Research and development in information retrieval (1986)

The ability to effectively rank retrieved documents in order of their probable relevance to a query is a critical factor in statistically-based keyword retrieval systems. This paper summarizes a set of experiments with different methods of term weighting for documents, using measures of term importance within an entire document collection, term importance within a given document, and document length. It is shown that significant improvements over no term weighting can be made using a combination of weighting measures and normalizing for document length.
Enhancing simulation education with intelligent tutoring systems
Authors: Simon J. E. Taylor, Julika Siemer
Venue: Proceedings of the 28th conference on Winter simulation (1996)

The demand for education in the area of simulation is in the increase. This paper describes how education in the field of simulation can take advantage of the virtues of intelligent tutoring with respect to enhancing the educational process. For this purpose, this paper gives an overview of what constitutes the objectives and the content of a comprehensive course in discrete event simulation. The architecture of an intelligent tutoring system is presented and it is discussed how these sophisticated learning aids offer individualised student guidance and support within a learning environment. The paper then introduces a prototype intelligent tutoring system, the simulation tutor, and suggests how the system might be developed to enhance education in simulation.
Characterization of the Sonar Signals Benchmark
Authors: Juan Manuel Torres Moreno, Mirta B. Gordon
Venue: Neural Processing Letters (1998)

We study the classification of sonar targets first introduced by Gorman Sejnowski (1988). We discovered that not only the training set and the test set of this benchmark are both linearly separable, although by different hyperplanes, but that the complete set of patterns, training and test patterns together, is also linearly separable. The distances of the patterns to the separating hyperplane determined by learning with the training set alone, and to the one determined by learning the complete data set, are presented.
Construction of a (64, 2 ^{ 37}, 12) Codevia Galois Rings
Authors: A. R. Calderbank, Gary Mcguire
Venue: Designs, Codes and Cryptography (1997)

Certain nonlinear binary codes contain more codewords than any comparable linear code presently known. These include the Kerdock and Preparata codes, which exist for all lengths 4^m &ge; 16. At length 16 they coincide to give the Nordstrom-Robinson code. This paper constructs a nonlinear (64, 2^37, 12) code as the binary image, under the Gray map, of an extended cyclic code defined over the integers modulo 4 using Galois rings. The Nordstrom-Robinson code is defined in this same way, and like the Nordstrom-Robinson code, the new code is better than any linear code that is presently known.
A Parallel Algorithm for Graph Matching and Its MasPar Implementation
Authors: Robert Allen, Luigi Cinque, Steven Tanimoto, Linda Shapiro, Dean Yasuda
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

Search of discrete spaces is important in combinatorial optimization. Such problems arise in artificial intelligence, computer vision, operations research, and other areas. For realistic problems, the search spaces to be processed are usually huge, necessitating long computation times, pruning heuristics, or massively parallel processing. We present an algorithm that reduces the computation time for graph matching by employing both branch-and-bound pruning of the search tree and massively-parallel search of the as-yet-unpruned portions of the space. Most research on parallel search has assumed that a multiple-instruction-stream/multiple-data-stream (MIMD) parallel computer is available. Since massively parallel single-instruction-stream/multiple-data-stream (SIMD) computers are much less expensive than MIMD systems with equal numbers of processors, the question arises as to whether SIMD systems can efficiently handle state-space search problems. We demonstrate that the answer is yes, and in particular, that graph matching has a natural and efficient implementation on SIMD machines.
Parametric Shape-from-Shading by Radial Basis Functions
Authors: Guo-Qing Wei, Gerd Hirzinger
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

In this paper, we present a new method of shape from shading by using radial basis functions to parameterize the object depth. The radial basis functions are deformed by adjusting their centers, widths, and weights such that the intensity errors are minimized. The initial centers and widths are arranged hierarchically to speed up convergence and to stabilize the solution. Although the smoothness constraint is used, it can be eventually dropped out without causing instabilities in the solution. An important feature of our parametric shape-from-shading method is that it offers a unified framework for integration of multiple sensory information. We show that knowledge about surface depth and/or surface normals anywhere in the image can be easily incorporated into the shape from shading process. It is further demonstrated that even qualitative knowledge can be used in shape from shading to improve 3D reconstruction. Experimental comparisons of our method with several existing ones are made by using both synthetic and real images. Results show that our solution is more accurate than the others.
A generic collaborative database&mdash;part of a strategy to internationalise the curriculum and develop teamwork and communication capabilities (poster)
Authors: A. G. Clear
Venue: ACM SIGCSE Bulletin (1998)

This presentation reports on progress in using Groupware concepts, to assist collaborative learning across boundaries of time and space, to broaden the student learning experience and develop capabilities in the use of IT for cross cultural communication.
Partitioning Quadrics, Symmetric Group Divisible Designsand Caps
Authors: Aiden A. Bruen, David L. Wehlau
Venue: Designs, Codes and Cryptography (1997)

Using partitionings of quadrics we give a geometric construction of certain symmetric group divisible designs. It is shown that some of them at least are self-dual. The designs that we construct here relate to interesting work &mdash; some of it very recent &mdash; by D. Jungnickel and by E. Moorhouse. In this paper we also give a short proof of an old result of G. Pellegrino concerning the maximum size of a cap in AG(4,3) and its structure. Semi-biplanes make their appearance as part of our construction in the three dimensional case.
Fingerprint Image Enhancement: Algorithm and Performance Evaluation
Authors: Lin Hong, Yifei Wan, Anil Jain
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1998)

A critical step in automatic fingerprint matching is to automatically and reliably extract minutiae from the input fingerprint images. However, the performance of a minutiae extraction algorithm relies heavily on the quality of the input fingerprint images. In order to ensure that the performance of an automatic fingerprint identification/verification system will be robust with respect to the quality of input fingerprint images, it is essential to incorporate a fingerprint enhancement algorithm in the minutiae extraction module. We present a fast fingerprint enhancement algorithm, which can adaptively improve the clarity of ridge and valley structures of input fingerprint images based on the estimated local ridge orientation and frequency. We have evaluated the performance of the image enhancement algorithm using the goodness index of the extracted minutiae and the accuracy of an online fingerprint verification system. Experimental results show that incorporating the enhancement algorithm improves both the goodness index and the verification accuracy.
Efficient procedure mapping using cache line coloring
Authors: Amir H. Hashemi, David R. Kaeli, Brad Calder
Venue: Proceedings of the ACM SIGPLAN 1997 conference on Programming language design and implementation (1997)

As the gap between memory and processor performance continues to widen, it becomes increasingly important to exploit cache memory eflectively. Both hardware and aoftware approaches can be explored to optimize cache performance. Hardware designers focus on cache organization issues, including replacement policy, associativity, line size and the resulting cache access time. Software writers use various optimization techniques, including software prefetching, data scheduling and code reordering. Our focus is on improving memory usage through code reordering compiler techniques.In this paper we present a link-time procedure mapping algorithm which can significantly improve the eflectiveness of the instruction cache. Our algorithm produces an improved program layout by performing a color mapping of procedures to cache lines, taking into consideration the procedure size, cache size, cache line size, and call graph. We use cache line coloring to guide the procedure mapping, indicating which cache lines to avoid when placing a procedure in the program layout. Our algorithm reduces on average the instruction cache miss rate by 40% over the original mapping and by 17% over the mapping algorithm of Pettis and Hansen [12].
A Lower Bound for Adjacencies on the Traveling Salesman Polytope
Authors: A. Sarangarajan
Venue: SIAM Journal on Discrete Mathematics (1997)

We study adjacency of vertices on Tn, the asymmetric traveling salesman polytope of degree n. Applying a result of G. Boccara [Discrete Math., 29 (1980), pp. 105--134] to permutation groups, we show that Tn has $\Omega((n-1)(n-2)!\,^2 \log n)$ edges, implying that the degree of a vertex of Tn is $\Omega((n-2)! \log n)$. We conjecture the degree to be $\Omega((n-2)! (\log n)^k)$ for any positive integer k. We compute the density function $\delta_n$ given by the fraction of the total number of vertices adjacent to a given vertex for small values of $n$, and conjecture that it decreases with n.
Use of computer conferencing to teach a course on humans and computers
Authors: Jacob Palme, Sirkku Männikö
Venue: Proceedings of the 2nd conference on Integrating technology into computer science education (1997)

A course with the name "Humans, society and computers" was given using a non-simultaneous computer conferencing system (BBS system).
Branch-and-Price Algorithms for the One-Dimensional Cutting Stock Problem
Authors: Pamela H. Vance
Venue: Computational Optimization and Applications (1998)

We compare two branch-and-price approaches for the cutting stock problem. Each algorithm is based on a different integer programming formulation of the column generation master problem. One formulation results in a master problem with 0&ndash;1 integer variables while the other has general integer variables. Both algorithms employ column generation for solving LP relaxations at each node of a branch-and-bound tree to obtain optimal integer solutions. These different formulations yield the same column generation subproblem, but require different branch-and-bound approaches. Computational results for both real and randomly generated test problems are presented.
Tuning compiler optimizations for simultaneous multithreading
Authors: Jack L. Lo, Susan J. Eggers, Henry M. Levy, Sujay S. Parekh, Dean M. Tullsen
Venue: Proceedings of the 30th annual ACM/IEEE international symposium on Microarchitecture (1997)

Compiler optimizations are often driven by specific assumptions about the underlying architecture and implementation of the target machine. For example, when targeting shared-memory multiprocessors, parallel programs are compiled to minimize sharing, in order to decrease high-cost, inter-processor communication. This paper reexamines several compiler optimizations in the context of simultaneous multithreading (SMT), a processor architecture that issues instructions from multiple threads to the functional units each cycle. Unlike shared-memory multiprocessors, SMT provides and benefits from fine-grained sharing of processor and memory system resources; unlike current multiprocessors, SMT exposes and benefits from inter-thread instruction-level parallelism when hiding latencies. Therefore, optimizations that are appropriate for these conventional machines may be inappropriate for SMT. We revisit three optimizations in this light: loop-iteration scheduling, software speculative execution, and loop tiling. Our results show that all three optimizations should be applied differently in the context of SMT architectures: threads should be parallelized with a cyclic, rather than a blocked algorithm; non-loop programs should not be software speculated and compilers no longer need to be concerned about precisely sizing tiles to match cache sizes. By following these new guidelines compilers can generate code that improves the performance of programs executing on SMT machines.
Introducing fixed-point iteration early in a compiler course
Authors: Max Hailperin
Venue: ACM SIGCSE Bulletin (1997)

When teaching a course in compiler design, it is conventional to introduce the iterative calculation of least fixed points quite late in the course, in the guise of iterative data-flow analysis. In this paper I point out that the same mathematical and algorithmic ideas can be introduced much earlier, in the parsing portion of the course, as an explanation of the standard algorithm for computing the First sets of a context-free grammar. Doing so not only renders these techniques more familiar when they re-appear in data-flow analysis, it also provides a more sound foundation for the First algorithm than is typically offered. Moreover, these techniques deserve increased curricular prominence because they naturally lead to proofs of correctness for general non-deterministic algorithms that subsume multiple deterministic algorithms.
Generalized Affine Invariant Image Normalization
Authors: Dinggang Shen, Horace H. S. Ip
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

We provide a generalized image normalization technique which basically solved all problems in image normalization. The orientation of any image can be uniquely defined by at most three non-zero generalized complex (GC) moments. The correctness of our method is demonstrated theoretically as well as in practice by applying them to a number of "degenerate" images which have failed other previously reported techniques for image normalization.
On Two Interior-Point Mappings for Nonlinear Semidefinite Complementarity Problems
Authors: R. D. C. Monteiro, Jong-Shi Pang
Venue: Mathematics of Operations Research (1998)

Extending our previous work ( Monteiro and Pang 1996), this paper studies properties of two fundamental mappings associated with the family of interior-point methods for solving monotone nonlinear complementarity problems over the cone of symmetric positive semidefinite matrices. The first of these maps lead to a family of new continuous trajectories which include the central trajectory as a special case. These trajectories completely "fill up" the set of interior feasible points of the problem in the same way as the weighted central paths do the interior of the feasible region of a linear program. Unlike the approach based on the theory of maximal monotone maps taken by Shida and Shindoh (1996) and Shida, Shindoh, and Kojima (1995), our approach is based on the theory of local homeomorphic maps in nonlinear analysis.
Adaptive flow control in time warp
Authors: Kiran S. Panesar, Richard M. Fujimoto
Venue: ACM SIGSIM Simulation Digest (1997)

It is well known that Time Warp may suffer from poor performance due to excessive rollbacks caused by overly optimistic execution. Here we present a simple flow control mechanism using only local information and GVT that limits the number of uncommitted messages generated by a processor, thus throttling overly optimistic TW execution. The flow control scheme is analogous to traditional networking flow control mechanisms. A ``window'' of messages defines the maximum number of uncommitted messages allowed to be scheduled by a process. Committing messages is analogous to acknowledgments in networking flow control. The initial size of the window is calculated using a simple analytical model that estimates the instantaneous number of messages that a process will eventually commit. This window is expanded so that the process may progress up to the next commit point (generally the next fossil collection), and to accommodate optimistic execution. The expansions to the window are based on monitoring TW performance statistics so the window size automatically adapts to changing program behaviors.The flow control technique presented here is simple and fully automatic. No global knowledge or synchronization (other than GVT) is required. We also develop an implementation of the flow control scheme for shared memory multiprocessors that uses dynamically sized pools of free message buffers. Experimental data indicates that the adaptive flow control scheme maintains high performance for "balanced workloads'', and achieves as much as a factor of 7 speedup over unthrottled TW for certain irregular workloads.
Supercomputer-based visualization systems used for analyzing output data of a numerical weather prediction model
Authors: Philip C. Chen
Venue: ACM SIGARCH Computer Architecture News (1990)

Comparison of two supercomputer-based visualization systems developed over a half-year period show that the visualization/animation efficiency is largely dependent upon the efficiencies of individual computers, networking, and memory management. Using a meteorological database, a case study is presented to illustrate a selection of parameters based on physical laws. Then, three-dimensional animations of selected parameters are made and used for investigating the evolutions of winter cyclone systems. The results indicate an animation with combined parameters that are physically related and reveal important cyclonic development mechanisms that could not have been seen by an animation with an individual parameter.
Data Set A is a Pattern Matching Problem
Authors: Jens Kohlmorgen, Klaus-Robert Müller
Venue: Neural Processing Letters (1998)

Several data sets have been proposed for benchmarking in time series prediction. A popular one is Data Set A from the Santa Fe Competition. This data set was the subject of analysis in many papers. In this note, it is shown that predicting the continuation of Data Set A is nothing else than a pattern matching problem. Looking at studies of this data set, it is remarkable that most of the very good forecasts of Data Set A used upsampled training data. We explain why upsampling is crucial for this data set. Finally, it is demonstrated that simple pattern matching performs as good as sophisticated prediction methods on Data Set A.
Classifier systems and economic modeling
Authors: Johann Mitlöhner
Venue: ACM SIGAPL APL Quote Quad (1996)

Human economic decisions are characterized by a number of factors which make them difficult to model with standard mathematical tools. Decisions can be more easily described by a set of rules, and some of them may be "rules of thumb". Economic behavior is adaptive, in that people are able to adjust to a changing environment. It is argued in this paper that the classifier system framework is a suitable means of modeling human economic decisions. A case of a simple economic decision of finding an optimal price is discussed, which is later made more complex by introducing an input variable that effects the optimal price. It is shown that classifier systems can be used in both tasks, and their performance is compared to human decisions in the same set of circumstances.