ppxscal/embedding_network huggingface dataset:
The inverse nearest neighbor problem with astrophysical applications
Authors: Richard Anderson, Brian Tjaden
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

This paper discusses algorithmic improvements to mature astrophysics applications as part of an on-going collaboration with Astrophysicists. We present an efficient algorithm for a variation of the Inverse Nearest Neighbor problem which is a basic computation in an astrophysical N-body simulation. We obtain empirical results demonstrating the improvements, which our algorithm offers to large-scale astrophysical simulations.
Design and implementation of move-based heuristics for VLSI hypergraph partitioning
Authors: Andrew E. Caldwell, Andrew B. Kahng, Igor L. Markov
Venue: Journal of Experimental Algorithmics (JEA) (2000)

We summarize the techniques of implementing move-based hypergraph partitioning heuristics and evaluating their performance in the context of VLSI design applications. Our first contribution is a detailed software architecture, consisting of seven reusable components, that allows flexible, efficient and accurate assessment of the practical implications of new move-based algorithms and partitioning formulations. Our second contribution is an assessment of the modern context for hypergraph partitioning research for VLSI design applications. In particular, we discuss the current level of sophistication in implementation know-how and experimental evaluation, and we note how requirements for real-world partitioners - if used as motivation for research - should affect the evaluation of prospective contributions. Two "implicit decisions" in the implementation of the Fiduccia-Mattheyses heuristic are used to illustrate the difficulty of achieving meaningful experimental evaluation of new algorithmic ideas.
An insertion technique for one-sided height-balanced trees
Authors: D. S. Hirschberg
Venue: Communications of the ACM (1976)

A restriction on height-balanced binary trees is presented. It is seen that this restriction reduces the extra memory requirements by half (from two extra bits per node to one) and maintains fast search capabilities at a cost of increased time requirements for inserting new nodes.
Towards practical deteministic write-all algorithms
Authors: Bogdan S. Chlebus, Stefan Dobrev, Dariusz R. Kowalski, Grzegorz Malewicz, Alex Shvartsman, Imrich Vrto
Venue: Proceedings of the thirteenth annual ACM symposium on Parallel algorithms and architectures (2001)

The problem of performing t tasks on n asynchronous or undependable processors is a basic problem in parallel and distributed computing. We consider an abstraction of this problem called the Write-All problem&mdash; using n processors write 1's into all locations of an array of size t. The most efficient known deterministic asynchronous algorithms for this problem are due to Anderson and Woll. The first class of algorithms has work complexity of &Ogr;(t . n &egr;), for n &nle; ty and any &egr; > 0, and they are the best known for the full range of processors (n = t). To schedule the work of the processors, the algorithms use sets of q permutations on [q] (q &nle; n) that have certain combinatorial properties. Instantiating such an algorithm for a specific &egr; either requires substantial pre-processing (exponential in 1/&egr;2) to find the requisite permutations, or imposes a prohibitive constant (exponential in 1/&egr;3) hidden by the asymptotic analysis. The second class deals with the specific case of t = nu, u &nle; 2, and these algorithms have work complexity of &Ogr;(t log t). They also use sets of permutations with the same combinatorial properties. However instantiating these algorithms requires exponential in n preprocessing to find the permutations. To alleviate this costly instantiation Kanellakis and Shvartsman proposed a simple way of computing the permutation schedules. They conjectured that their construction has the desired properties but they provided no analysis. In this paper we show, for the first time, an analysis of the properties of the set of permutations proposed by Kanellakis and Shvartsman. Our result is hybrid as it includes analytical and empirical parts. The analytical result covers a subset of the possible adversarial patterns of asynchrony. The empirical results provide strong evidence that our analysis covers the worst case scenario, and we formally state it as a conjecture. We use these results to analyze an algorithm for t = nu (u &gne; 2), tasks, that takes advantage of processor slackness and that has work &Ogr;(t log2 t), conditioned on our conjecture. This algorithm requires only &Ogr;(n log n) time to instantiate it. Next we study the case for the full range of processors n &nle; t. We define a family of deterministic asynchronous Write-All algorithms with work &Ogr;(t . n &egr;) contingent upon our conjecture. We show that our method yields a faster construction of &Ogr;(t . n &egr;) Write-All algorithms than the method developed by Anderson and Woll. Finally we show that our approach yields more efficient Write-all algorithms as compared to the algorithms induced by the constructions of Naor and Roth for the same asymptotic work complexity.
The sequence of the human genome (abstract only)
Authors: Mark Adams
Venue: Proceedings of the fifth annual international conference on Computational biology (2001)

A consensus sequence of the euchromatic portion of human genome has been generated by the whole genome shot-gun sequencing method that was developed while sequencing the genomes of Haemophilus influenzae and Drosophila melanogaster. The 2.9 billion bp sequence, was generated over nine months from 27,271,853 high quality sequence reads (&nsim;5X coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals: three females and two males of African-American, Asian-Chinese, Hispanic and Caucasian ethnicity. The coverage of the genome in cloned DNA represented by paired end-sequences exceeds 37X. Two assembly methods, a whole genome assembly and a regional hybrid assembly were utilized, combining BAC data from GenBank with Celera data. Over 90 assemblies of 500,000 bp or greater and 2510 million bp or larger. Analysis of the genome sequence reveals - 26,178 protein-encoding genes for which there is strong corroborating evidence and an additional 12,000 computationally derived genes with mouse homologues or other weak supporting evidence. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, tissue-specific developmental regulation, and in the hemostasis and immune systems. DNA sequence comparisons among the five individuals provided locations of 2.6 million single nucleotide polymorphisms (SNPs). The haploid genomes of a randomly drawn pair of humans differ at a rate of one per 1,250 bp on average but there is marked heterogeneity in the level of polymorphism across the genome. Only 0.75% of the SNPs led to possibly dysfunctional proteins.
Design of robust global power and ground networks
Authors: S. Boyd, L. Vandenberghe, A. El Gamal, S. Yun
Venue: Proceedings of the 2001 international symposium on Physical design (2001)

We consider the problem of determining optimal wire widths for a power or ground network, subject to limits on wire widths, voltage drops, total wire area, current density, and power dissipation. To account for the variation of the current demand, we model it as a random vector with known statistics, possibly including correlation between subsystem currents. Other researchers have shown that when the variation in the current is not taken into account, the optimal network topology is a tree. A tree topology is, however, almost never used in practice, because it is not robust with respect to variations in the lock currents. We show that when the current variation is taken into account, the optimal network is usually not a tree.We formulate a heuristic method based on minimizing a linear combination of total average power and total wire area. We show that this results in designs that obey the reliability constraints, occupy small area, and most importantly are robust against variations in block currents. The problem can be formulated as a nonlinear convex optimization problem that can be globally solved very effciently.
The Load and Availability of Byzantine Quorum Systems
Authors: Dahlia Malkhi, Michael K. Reiter, Avishai Wool
Venue: SIAM Journal on Computing (2000)

Replicated services accessed via quorums enable each access to be performed at only a subset (quorum) of the servers and achieve consistency across accesses by requiring any two quorums to intersect. Recently, b-masking quorum systems, whose intersections contain at least 2b+1 servers, have been proposed to construct replicated services tolerant of b-arbitrary (Byzantine) server failures. In this paper we consider a hybrid fault model allowing benign failures in addition to the Byzantine ones. We present four novel constructions for b-masking quorum systems in this model, each of which has optimal load (the probability of access of the busiest server) or optimal availability (probability of some quorum surviving failures). To show optimality we also prove lower bounds on the load and availability of any b-masking quorum system in this model.
Requirements for models of achievable routing
Authors: A. B. Kahng, S. Mantik, D. Stroobandt
Venue: Proceedings of the 2000 international conference on Computer-aided design (2001)

Models of achievable routing, i.e., chip wireability, rely on estimates of available and required routing resources. Required routing resources are estimated from placement, or (a priori) using wirelength estimation models. Available routing resources are estimated by calculating a nominal "supply", then taking into account such factors as the efficiency of the router and the impact of vias. Models of achievable routing can be used to optimize interconnect process parameters for future designs or to supply objectives that guide layout tools to promising solutions. Such models must be accurate in order to be useful, and must support empirical verification and calibration by actual routing results. In this paper, we discuss the validation of such models and we apply our validation process to three existing models. We find notable inaccuracies in the existing models when matched against real data. We then present a thorough analysis of the assumptions underlying these models; based on this analysis, we discuss requirements for predictors of routing resources within models of achievable routing.
Teaching object-oriented development with emphasis on pattern application
Authors: Lew Della, David Clark
Venue: Proceedings of the Australasian conference on Computing education (2000)

One of the most significant recent developments in software engineering has been the widespread adoption of design patterns. Design patterns enable software developers to incorporate well proven solutions to design problems in their software. This makes their software more flexible and reusable. Design patterns, however, are not easy to learn. They are often presented in complex contexts with partially coded examples. Further, there is no standard naming convention, with designers using very different names for quite similar patterns. These problems limit the accessibility of design patterns to beginning students. In this paper we propose a teaching method to help in the understanding of design patterns and their usage by developing fully coded examples (in Java), of certain design patterns in a particular domain. The method centres around developing an application using a framework which has been constructed using patterns as the central plank of the constuction. The students are then required to develop a related application using the same framework. This approach attempts to make it easier for students to relate to patterns, and to see the link between design patterns and their implementation via these coded frameworks. The aim is a better appreciation of design patterns and a clearer understanding of how to apply them in developing object-oriented solutions.
System canvas: a new design environment for embedded DSP and telecommunication systems
Authors: Praveen K. Murthy, Etan G. Cohen, Steve Rowland
Venue: Proceedings of the ninth international symposium on Hardware/software codesign (2001)

We present a new design environment, called System Canvas, targeted at DSP and telecommunication system designs. Our environment uses an easy-to-use block-diagram syntax to specify systems at a very high level of abstraction. The block diagram syntax is based on formal semantics, and uses a number of different models of computation including cyclo-static dataflow, dynamic dataflow, and a discrete-event model. A key feature of our tool is that the user does not need to have an awareness of which model is being used; the models can be freely mixed and matched and a simulation can consist of an arbitrary combination of models. The blocks are written in `C'or `C++' and it is straightforward to write custom blocks and incorporate them into custom libraries. Other key features include the ability to control simulations via language-neutral scripts, and a powerful optimization engine that enables optimization of the system over arbitrarily specified parameters, constraints, and cost functions. Fixed-point analysis capability allows any signal or variable in the system to be set to any type of number system before the simulation proceeds. The tool is available on the Windows NT platform and incorporates modern and ubiquitous Windows GUI look and feel.
Further remarks on line segment curve-fitting using dynamic programming
Authors: Brian Gluss
Venue: Communications of the ACM (1962)

In a recent paper, Bellman showed how dynamic programming could be used to determine the solution to a problem previously considered by Stone. The problem comprises the determination, given N, of the N points of subdivision of a given interval (&agr;, &bgr; and the corresponding line segments, that give the best least squares fit to a function g(x) in the interval. Bellman confined himself primarily to the analytical derivation, suggesting briefly, however, how the solution of the equation derived for each particular point of subdivision ui could be reduced to a discrete search. In this paper, the computational procedure is considered more fully, and the similarities to some of Stone's equations are indicated. It is further shown that an equation for u2 involving no minimization may be found. In addition, it is shown how Bellman's method may be applied to the curve-fitting problem when the additional constraints are added that the ends of the line segments must be on the curve.
Elementary divisors of tensor products
Authors: Marvin Marcus, Herbert Robinson
Venue: Communications of the ACM (1975)

The elementary divisors of a tensor product of linear transformations have been known for 40 years. This paper provides a short, easily accessible proof of these results, and points out an interesting combinatorial consequence of the proof.
Analysing cache effects in distribution sorting
Authors: Naila Rahman, Rajeev Raman
Venue: Journal of Experimental Algorithmics (JEA) (2000)

We study cache effects in distribution sorting algorithms for sorting keys drawn independently at random from a uniform distribution ('uniform keys'). We note that the performance of a recently-published distribution sorting algorithm, Flashsort1, which sorts <i>n</i> uniform floating-point keys in <i>O(n)</i> expected time, does not scale well with the input size due to poor cache utilisation. We present an approximate analysis for distribution sorting uniform keys which, as validated by simulation results, predicts the expected cache misses of Flashsort1 quite well. Using this analysis, we design a multiple-pass variant of Flashsort1 which outperforms Flashsort1 and comparison-based algorithms on uniform floating-point keys for moderate to large values of <i>n</i>. Using experimental results we also show that the integer distribution sorting algorithm MSB radix sort performs well on both uniform integer and uniform floating-point keys.
Configuration for Adaptation &ndash; A Human-centeredApproach to Flexible Workflow Enactment
Authors: Gert Faustmann
Venue: Computer Supported Cooperative Work (2000)

The advantages of today's process management, such as efficiency and quality aspects, are achieved by enforcing detailed models of work processes. However, real world processes can be planned to a limited degree only and sometimes planned parts of the process must be changed, creating a need for additional, unforeseen activities. This paper suggests an approach that configures parts of a detailed process model with different support strategies. The explicit modelling of these support strategies allows them to be changed if demanded by the situation. When enacting such a process model it is then possible to vary the degree to which the model determines the work of individuals. The concept is based on an earlier enactment concept which allowed workers to freely choose methods for their tasks according to the situation. Besides the incorporation of different support strategies, the extended enactment strategy gives workers the opportunity to negotiate about changing a currently too restrictive support strategy, giving scope for deviations from the planned process where additional actions are required.
An Improved Generalization of Mesh-Connected Computers with Multiple Buses
Authors: Yi Pan, S. Q. Zheng, Keqin Li, Hong Shen
Venue: IEEE Transactions on Parallel and Distributed Systems (2001)

Mesh-connected computers (MCCs) are a class of important parallel architectures due to their simple and regular interconnections. However, their performances are restricted by their large diameters. Various augmenting mechanisms have been proposed to enhance the communication efficiency of MCCs. One major approach is to add nonconfigurable buses for improved broadcasting. A typical example is the mesh-connected computer with multiple buses (MMB). We propose a new class of generalized MMBs, the improved generalized MMBs (IMMBs). We compare IMMBs with MMBs and a class of previously proposed generalized MMBs (GMMBs). We show the power of IMMBsby considering semigroup and prefix computations. Specifically, as our main result we show thatfor any constant $0
Document generation using ASIS tools
Authors: Steven V. Hovater
Venue: ACM SIGAda Ada Letters (2000)

The Ada Semantic Interface Specification offers a unique capability to Ada development projects: the ability to construct tools that navigate through the semantic network formed by one's compiled code. In particular, producing accurate documentation based upon existing source code is a possibility; if one can identify the composite types that act as messages between different parts of one's system, then it is entirely feasible to generate an interface description document based upon the actual content of the code, thus automating what has been historically, a tedious process. hellip;
The base-rate fallacy and the difficulty of intrusion detection
Authors: Stefan Axelsson
Venue: ACM Transactions on Information and System Security (TISSEC) (2000)

Many different demands can be made of intrusion detection systems. An important requirement is that an intrusion detection system be effective; that is, it should detect a substantial percentage of intrusions into the supervised system, while still keeping the false alarm rate at an acceptable level. This article demonstrates that, for a reasonable set of assumptions, the false alarm rate is the limiting factor for the performance of an intrusion detection system. This is due to the base-rate fallacy phenomenon, that in order to achieve substantial values of the Bayesian detection rate P(Intrusion***Alarm), we have to achieve a (perhaps in some cases unattainably) low false alarm rate. A selection of reports of intrusion detection performance are reviewed, and the conclusion is reached that there are indications that at least some types of intrusion detection have far to go before they can attain such low false alarm rates.
Competitive and Temporal Inhibition Structures with Spiking Neurons
Authors: E. Ros, F. J. Pelayo, P. Martin-Smith, I. Rojas, D. Palomar, A. Prieto
Venue: Neural Processing Letters (2000)

The paper describes the implementation of competitive neural structures based on a spiking neural model that includes multiplicative or shunting synapses enabling non-saturated stable states in response to different stationary inputs as well as controllable transient responses. A VLSI-viable implementation of this model has been previously proposed and tested [1]. It has the possibility of modulating the output spike frequency by an additional input without affecting other neuron variables such as the membrane potential. This feature is exploited in the simulation of a Selective Temporal Inhibition network that is suitable for implementing attentional control systems.
Stabilization of Multidimensional Systems Using Local StateEstimators
Authors: Tatsushi Ooba
Venue: Multidimensional Systems and Signal Processing (2001)

A design method for stabilizing a multidimensional system is proposed. The deign method is developed from the viewpoint of Lyapunov stability and it is based on two Riccati like matrix inequalities those ensure the stabilizability and the detectability of a multidimensional system in a strong sense. The arrangement scheme of the stabilizer is set up as a combination of plant and local state estimator, which imitates the well-known compensator design for 1-D systems incorporated with full order state observer.
Integrating drawing tools with behavioral modeling in digital painting
Authors: Elpida S. Tzafestas
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

Our goal is to integrate traditional artistic media that demand hand dexterity (such as drawing) with intelligent systems techniques that may both constrain and nourish this dexterity. To this end we are experimenting with special brush tools that on top of traditional drawing provide possibilities that involve information processing and behavioral modeling. In this work, we are introducing a behavioral model as a color processing feature of our brush. More precisely, we use a regulation mechanism, that has been shown elsewhere to solve a typical problem in artificial ant societies, to distribute color on the drawing canvas. Our drawing tool, called &ldquo;AntBrush&rdquo;, manages to create controlled color variety during drawing by regulating its own quantity of color through picking and depositing color on the canvas. Different color effects are possible by controlling the brush's parameters on line.
Sensitivity of Performance Prediction of Message Passing Programs
Authors: Sergi Girona, Jesús Labarta
Venue: The Journal of Supercomputing (2000)

This paper discusses the issues related to the accuracy of performance prediction tools for message passing programs. We present the results of two sets of experiments to quantify the effect of the instrumentation overhead and variance in the accuracy of Dimemas. The results show that this performance prediction tool can be used with a high level of confidence as the effect of instrumentation overhead on the predicted performance is minimal. We also show that it is possible to carry out instrumentation runs in highly loaded multi-user environments and still be able to accurately analyze the performance of the application as if it had run alone.
Synthesis of decision rules
Authors: Cheng-Wen Cheng, Jonas Rabin
Venue: Communications of the ACM (1976)

Decision tables can be used as an effective tool during an interview to record the logic of processes to be automated. The result of such an interview is not a structure of complete decision tables but rather sets of decision rules. The purpose of this paper is to provide a procedure for synthesizing the decision rules and thus provide an aid in developing a structure of complete decision tables.