ppxscal/embedding_network huggingface dataset:
Optimization algorithms forseparable functions with tree-like adjacency of variables and theirapplication to the analysis of massive data sets
Authors: Ilya Muchnik, Vadim Mottl
Venue:  (1997)

A massive data set is considered as a set of experimentally acquired values of a number of variables each of which is associated with the respective node of an unoriented conjugacy graph that presets the fixed structure of the data set. The class of data analysis problems under consideration is outlined by the assumption that the ultimate aim of processing can be represented as a transformation of the original data array into a secondary array of the same structure but with node variables of, generally speaking, different nature, i.e. different ranges. Such a generalized problem is set as the formal problem of optimization (minimization or maximization) of a real-valued objective function of all the node variables. The objective function is assumed to consist of additive constituents of one or two arguments, respectively, node and edge functions. The former of them carry the data-dependent information on the sought-for values of the secondary variables, whereas the latter ones are meant to express the a priori model constraints. For the case when the graph of the pair-wise adjacency of the data set elements has the form of a tree, an effective global optimization procedure is proposed which is based on a recurrent decomposition of the initial optimization problem over all the node variables into a succession of partial problems each of which consists in optimization of a function of only one variable like Bellman functions in the classical dynamic programming. Two kinds of numerical realization of the basic optitimization procedure are considered on the basis of parametrical representation of Bellman functions, respectively, for discretely defined and quadratic node and edge functions. The proposed theoretical approach to the analysis of massive data sets is illustarted with its applications to the problems of the analysis of long molecular sequences and large visual images.
Parallel Algorithms For Maximum Matching And Other Problems On Interval Graphs
Authors: Abha Moitra, Richard C. Johnson
Venue:  (1988)

In this paper, we consider parallel algorithms on interval graphs. An interval graph is a graph having a one-to-one correspondence with a sequence of intervals on the real line, such that each vertex maps to an interval in the sequence and an edge exists between two vertices if and only if the corresponding intervals overlap. Throughout the paper we use the CREW PRAM model. Our main result is an $O(\log^{2} n)$ time, $O(n^{6}/\log n)$ processor algorithm for maximum matching on interval graphs. We give PT-optimal algorithms for maximum weighted clique, maximum independent set, minimum clique cover, and minimum dominating set for representations of interval graphs; and Hamiltonian circuit for representations of proper interval graphs. We also give an improved algorithm for minimum bandwidth on representations of proper interval graphs. In addition, we present $O (\log n)$ time, $O (n^{2}/\log n)$ processor algorithms for depth-first search on representations of interval graphs and maximum matching on representations of proper interval graphs.
Analysis of multiple quickselect variants
Authors: Alois Panholzer
Venue: Theoretical Computer Science (2003)

Multiple Quickselect is an algorithm that uses the idea of Quicksort to search for several order statistics simultaneously. In order to improve the efficiency of Quicksort, one can use the median of 2t + 1 randomly chosen elements as pivot element in the partitioning stage. Such a median of 2t + 1 partition can also be applied to Multiple Quickselect to reduce the number of comparisons. Here we give an analysis of such Multiple Quickselect variants that use median of 2t + 1 partition and describe for these algorithms the asymptotic behaviour of the expected number of required comparisons to find p-order statistics in a data set of size n for n → ∞ and fixed p.
Effective Mutation Rate for Probabilistic Models in Evolutionary Analog Circuit Design
Authors: Heinz Mühlenbein, Lyudmilla Zinchenko, Victor Kureichik, Thilo Mahnig
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

This paper represents the following improvement of evolutionary analog circuit design on the base of the univariate marginal distribution algorithm. Experiments have indicated that the high mutation rate increases the success rate, although the computational expenses are increased as well. An effective mutation rate is considered with respect to a high success rate and smallcomputational expenses. Experiments for analog arrays are discussed.
Independent Spanning Trees with Small Stretch Factors
Authors: Fred Annexstein, Ken Berman, Ram Swaminathan
Venue:  (1996)

A pair of spanning trees rooted at a vertex "r" are independent if for every vertex "v" the pair of unique tree paths from "v" to the root "r" are disjoint. This paper presents the first analysis of the path lengths involved in independent spanning trees in 2-edge-connected and 2-vertex-connected graphs. We present upper and lower bounds on the stretch factors of pairs of independent spanning trees, where the stretch factor of a spanning tree is defined to be the maximum ratio between the length of paths in the tree to the root to the length of the shortest path in the graph to the root. We prove that if "G" is a 2-edge-connected graph with the property that every edge lies on a cycle of size at most "h", then we can construct in linear time a pair of edge-independent spanning trees whose stretch factors are bounded by O(h). In fact, we prove a more general result, namely that the stretch factor of both independent trees can be bounded by a minimax length of ears with respect to a certain class of ear decompositions of the graph. We demonstrate analogous constructions of vertex-independent spanning trees with bounded stretch factors for the class of 2-vertex-connected graphs. We show that our upper bounds are existentially optimal, that is, there are classes of graphs for which our bounds are tight. --------------------------------------- The last author would like to acknowledge the hospitality of DIMACS Center.
Regular multicast multihop lightwave networks
Authors: S. Jiang, T. E. Stern
Venue: Proceedings of the Fourteenth Annual Joint Conference of the IEEE Computer and Communication Societies (Vol. 2)-Volume - Volume 2 (1995)

A class of multicast multihop lightwave networks (MLNs) is presented. These networks have a two-layered architecture, with the upper "logical layer" implemented electronically, and supported by an underlying "physical layer" implemented as a purely optical network. The unique feature studied is that the logical topology has a regular multicast structure, which is created through the use of optical multicast in the physical layer. It is shown that this type of logical topology yields networks which have significantly superior performance features, when compared with either purely optical networks, or with multihop networks based on point-to-point connections. Special regular logical topologies based on Kautz hypergraphs are used in designing the networks.
A Relational Approach to the Compilation of Sparse Matrix Programs
Authors: Vladimir Kotlyar, Keshav Pingali, Paul Stodghill
Venue:  (1997)

We present a relational algebra based framework for compiling efficient sparse matrix code from dense DO-ANY loops and a specification of the representation of the sparse matrix. We present experimental data that demonstrates that the code generated by our compiler achieves performance competitive with that of hand-written codes for important computational kernels.
Alex A Paradigm for Expressing and Compiling Matrix Functions
Authors: Gene K. Ressler
Venue:  (1993)

This work presents formal and practical tools to support the Alex paradigm for expressing and compiling matrix functions. Alex programs are recursive definitions over matrices with the same flavor as the elegant FP languages of Backus. Many useful matrix algorithms can be expressed in both FP and Alex without any explicit index arithmetic. While FP is very difficult to compile to fast numerical codes, we show that Alex functions admit compile-time analyses and code generation techniques with efficient results. In particular, we give a type system that expresses matrix sizes and shapes, a sound and complete inference algorithm for these types, and a code generation algorithm that is space-efficient--storage is allocated only for user function parameters and results. Finally, we give an algorithm that determines when it is safe to replace call by value array parameters in the compiled code with call by reference. A compiler using these techniques generates C code from Alex programs which is at least as fast as code one would write by hand for some small problems. We conclude with discussion of how the fundamental techniques given here relate to previous work and how they should be extended to a general functional language or incorporated as a feature of an existing one.
Question-Answering System for Teaching Autistic Children to Reason about Mental States
Authors: Galitsky Boris
Venue:  (2000)

We build the natural language question-answering system to teach autistic patients reasoning about mental states. In accordance to our model of autism disorder, some reasoning patterns concerning perception of the concepts of knowing, believing and intention are corrupted. Based on this model, we have suggested the autism diagnosis and reasoning rehabilitation strategy, where the professional psychologists explained the autistic children the set of multi-agent scenarios. Experiments showed that acquiring of mental concepts based on our formalism helps autistic children not only to improve judgment interacting with other people, but also to stimulate the emotional development. Further evaluation of the model and rehabilitation technology is conducted with automatic training toolkit, implemented on the Internet. Asking questions about mental states of heroes of the scene or textual scenarios assists the revealing and training of the corrupted autistic reasoning. Natural language technology of semantic headers is applied, where the textual answer (explanation) is assigned with a mental formula, which is matched against the representation of an input question or command.
Responsive Security for Stored Data
Authors: Subramanian Lakshmanan, Mustaque Ahamad, H. Venkateswaran
Venue: Proceedings of the 23rd International Conference on Distributed Computing Systems (2003)

We present the design of a distributed store that offersvarious levels of security guarantees while tolerating a limitednumber of nodes that are compromised by an adversary.The store uses secret sharing schemes to offer securityguarantees namely availability, confidentiality and integrity.However, a pure secret sharing scheme could sufferfrom performance problems and high access costs. Weintegrate secret sharing with replication for better performanceand to keep access costs low. The tradeoffs involvedbetween availability and access cost on one hand and confidentialityand integrity on the other are analyzed. Our systemdiffers from traditional approaches such as state machineor quorum based replication that have been developedto tolerate Byzantine failures. Unlike such systems, weaugment replication with secret sharing and demonstratethat such a hybrid scheme offers additional flexibility that isnot possible with replication alone.
Boston University, Computer Science 1998 Proxy Trace
Authors: Adam Bradley
Venue:  (1999)

Abstract In a recent paper (Changes in Web Client Access Patterns: Characteristics and Caching Implications by Barford, Bestavros, Bradley, and Crovella) we performed a variety of analyses upon user traces collected in the Boston University Computer Science department in 1995 and 1998. A sanitized version of the 1995 trace has been publicly available for some time; the 1998 trace has now been sanitized, and is available from: http://www.cs.bu.edu/techreports/1999-011-usertrace-98.gz ftp://ftp.cs.bu.edu/techreports/1999-011-usertrace-98.gz This memo discusses the format of this public version of the log, and includes additional discussion of how the data was collected, how the log was sanitized, what this log is and is not useful for, and areas of potential future research interest.
Forced oscillation properties for certain systems of partial functional differential equations
Authors: Wei Nian Li
Venue: Applied Mathematics and Computation (2003)

Some sufficient conditions are established for the forced oscillation of certain systems of partial functional differential equations with deviating arguments. These results are illustrated by some examples.
Linear recurrent sequences and polynomial roots
Authors: Maurice Mignotte, Doru Ştefánescu
Venue: Journal of Symbolic Computation (2003)

We consider the problem of the determination of the largest modulus of a root of a complex polynomial P. We obtain lower and upper bounds using properties of appropriate linear recurrent sequences associated with P. This allows giving the absolute value of a dominant root as the limit as in Bernoulli's process. We finally discuss a rule of Jacobi in his refinement of Bernoulli's method. Relevant examples are obtained through pari and maple procedures.
Generalized processor sharing queues with heterogeneous traffic classes
Authors: Simon C. Borst, Michel R.H. Mandjes, M. J.G. Uitert
Venue:  (2001)

We consider a queue fed by a mixture of light-tailed and heavy-tailed traffic. The two traffic flows are served in accordance with the Generalized Processor Sharing (GPS) discipline. GPS-based scheduling algorithms, such as Weighted Fair Queueing (WFQ), have emerged as an important mechanism for achieving service differentiation in integrated networks. We derive the asymptotic workload behavior of the light-tailed traffic flow under the assumption that its GPS weight is larger than its traffic intensity. The GPS mechanism ensures that the workload is bounded above by that in an isolated system with the light-tailed flow served in isolation at a constant rate equal to its GPS weight. We show that the workload distribution is in fact asymptotically equivalent to that in the isolated system, multiplied with a certain pre-factor, which accounts for the interaction with the heavy-tailed flow. Specifically, the pre-factor represents the probability that the heavy-tailed flow is backlogged long enough for the light-tailed flow to reach overflow. The results provide crucial qualitative insight in the typical overflow scenario.
ALife investigation of parental investment in reproductive strategies
Authors: Steven Mascaro, Kevin B. Korb, Ann E. Nicholson
Venue: Proceedings of the eighth international conference on Artificial life (2002)

Many organisms nourish and care for their offspring, boosting the offspring's reproductive potential. Trivers (1972) recognized that such parental investment, when made differentially across the sexes, could explain the existence of sexually dimorphic behaviour. However, parental investment in nature is difficult to measure, and explanations involving parental investment are hard to verify. Here we use an ALife simulation to investigate the effect of explicit, numerical parental investments on two reproductive strategies of interest -- consensual mating and rape. With some preliminary empirical results, we demonstrate the potential of an ALife approach to evolutionary psychology.
NeuroFAST: High Accuracy Neuro-Fuzzy Modeling
Authors: Spyros G. Tzafestas, Konstantinos C. Zikidis
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

Most fuzzy modeling algorithms rely either on simplistic (grid type) or off-line (trial-and-error type)structure identification methods. The proposed neuro-fuzzy modeling architecture, NeuroFAST, is an on-line, structure and parameter learning algorithm, featuring high function approximation accuracy. It is based on the 1st -order Takagi-Sugeno-Kang (TSK) model (functional reasoning), where the consequence part of each fuzzy rule is a linear equation of the input variables. Fuzzy rules are allocated as learning evolves by a modified Fuzzy ART(Adaptive Resonance Theory) mechanism, assisted by fuzzy rule splitting and adding procedures (structure learning). The well known ä -rule continuously tunes learning weights on both premise and consequence parts (parameter identification). Tested on the Box-Jenkins gas furnace process modeling and the Mackey-Glass chaotic time series prediction, NeuroFAST yields very good results in terms of approximation accuracy, outperforming all known approaches.
HARP: Theory
Authors: and I Applications, HARP Research, B J Dugan, M R Geist, K M Smotherman, Beth Rothmann, Earl Smith, S K Trivedi
Venue:  (1987)

The NASA Langley Research Center has been actively pursuing the synthesis of a reliability assessment capability for fault-tolerant computer-based systems for more than a decade. This interest has given rise to several computer-aided reliability estimation packages, including CAST, CARE II, CARE III, SURE and HARP. CARE III is currently being distributed through COSMIC while both SURE and HARP are undergoing beta-testing. This report is a comprehensive description of the theory, implementation and applications of the HARP package. Accordingly, this report consists of three chapters. Each chapter is a slightly modified version of a previously published paper. The first chapter, ``Hybrid Reliability Modeling of Fault Tolerant Computer Systems'''', appeared in the {\em International Journal of Computers and Electrical Engineering} in 1984; the second chapter, ``HARP: The Hybrid Automated Reliability Predictor'''', appeared in the {\em AIAA Journal of Guidance, Control and Dynamics} in 1985; while the third chapter, ``Analysis of Typical Fault-Tolerant Architectures using HARP'''', appeared in the {\em IEEE Transactions on Reliability} in 1987.
Economics behind Latin American telecom privatizations?
Authors: C. H. Ganievich
Venue: Proceedings of the IEEE Symposium on Computers and Communications (ISCC'95) (1995)

We present a dynamic econometric model of the Mexican Telephone Company (Telmex). This model is used to compare different management strategies (state-owned monopoly, unregulated monopoly, regulated monopoly and competition) to find out the essential parameters that are pressing Latin American countries to restructure the telecom sector and to finally open it to competition. Simulating 16 years of behavior in various scenarios we show that long distance rates are the main reason forcing these fundamental changes.
A Generalized Broyden''s Method for Solving Simultaneous Linear Equations
Authors: Richard R. Gerber, Franklin T. Luk
Venue:  (1980)

We present a generalized Broyden''s method for solving rectangular systems of linear equations. We show that the method computes a least squares solution to the given simultaneous equations and that it posseses a remarkable finite termination property in exact arithmetic.
Parallel VLSI Synthesis
Authors: Markus G. Wloka
Venue:  (1991)

We investigate the parallel complexity of VLSI (very large scale integration) CAD (computer aided design) synthesis problems. Parallel algorithms are very appropriate in VLSI CAD because computationally intensive optimization methods are needed to derive ``good'''' chip layouts. We find that for many problems with polynomial-time serial complexity, it is possible to find an efficient parallel algorithm that runs in polylogarithmic time. We illustrate this by parallelizing the ``left-edge'''' channel routing algorithm and the one-dimensional constraint-graph compaction algorithm. Curiously enough, we find P-hard, or inherently difficult-to-parallelize algorithms when certain key heuristics are used to get approximate solutions to NP-complete problems. In particular, we show that many local search heuristics for problems related to VLSI placement are P-hard or P-complete. These include the Kernighan-Lin heuristic and the simulated annealing heuristic for graph partitioning. We show that local search heuristics for grid embeddings and hypercube embeddings based on vertex swaps are P-hard, as are any local search heuristics that minimize the number of column conflicts in a channel routing by accepting cost-improving swaps of tracks or subtracks. We believe that the P-hardness reductions we provide in this thesis can be extended to include many other important applications of local search heuristics. Local search heuristics have been established as the method of choice for many optimization problems whenever very good solutions are desired. Local search heuristics are also among the most time-consuming bottlenecks in VLSI CAD systems, and would benefit greatly from parallel speedup. Our P-hardness results make it unlikely, however, that the exact parallel equivalent of a local search heuristic will be found that can find even a local minimum-cost solution in polylogarithmic time. The P-hardness results also put into perspective experimental results reported in the literature: attempts to construct the exact parallel equivalent of serial simulated-annealing-based heuristics for graph embedding have yielded disappointing parallel speedups. We introduce the massively parallel {\it Mob} heuristic and report on experiments on the CM-2 Connection Machine. The design of the {\it Mob} heuristic was influenced by the P-hardness results. {\it Mob} can execute many moves of a local search heuristic in parallel. We applied our heuristic to the graph-partitioning, grid and hypercube-embedding problems, and report on an extensive series of experiments on the 32K-processor CM-2 Connection Machine that shows impressive reductions in edge costs. To obtain solutions that are within 5\ heuristic needed less than nine minutes of computation time on random graphs of two million edges, and the {\it Mob} grid and hypercube embedding heuristics needed less than 30 minutes on random graphs of one million edges. Due to excessive run times, heuristics reported previously in the lit