ppxscal/embedding_network huggingface dataset:
Snapshot simulation of internet traffic: fast and accurate for heavy-tailed flows
Authors: R. G. Addie
Venue: Proceedings of the 1st international conference on Simulation tools and techniques for communications, networks and systems & workshops (2008)

Simulations involving processes at very different time scales can be so slow to converge that starting in one state and waiting for a representative sample of the state space to be explored is not feasible. Under these circumstances we need to find a different way to explore a representative range of states in order to obtain valid results in a reasonable time. Internet traffic is an example of this situation. This is due to the fact that it is made up of clearly identifiable flows and a significant proportion of overall bytes occur in long-lived flows, whose overall duration will in many cases be longer than can be simulated. In this paper we develop a method which constructs a "randomly selected state" of Internet traffic from scratch -- snapshot simulation. The technique is applied to a realistic model of Internet traffic and is used to confirm theoretical results for the number of active flows in a router which adopts either Fair Queueing or Shortest Job First as its queueing discipline. Snapshot simulations are also compared to conventional simulations of the same systems and it is shown that although convergence to the same results appears to be occurring, satisfactory accuracy cannot be obtained in a reasonable time by the conventional simulations. Simulation of a practical high-performance queue discipline, SJF-n, in which only the largest n flows at any time are de-prioritized, is also simulated and shown to give good performance for quite low n.
Navigating the New Product Process from Strategic Viewpoint
Authors: Wang Kung-Jeng, Lee Yun-Huei, Wang Sophia
Venue: Proceedings of the international conference on Computational Science and Its Applications, Part II (2008)

Resource scarcity is a major difficulty facing firms that engage in new product development (NPD) projects. In order to understand how resource allocation strategies affect NPD performance and which strategy is the best alternative, we construct a research and development (R D) process model using system dynamics. Moreover, resource allocation strategies are categorized into two types: design-stage-first strategy and manufacturing-stage-first strategy, and several important indicators of performance evaluation are defined. We then use simulation to test the relationships between resource allocation strategy and various NPD performance measures. The most important finding from simulation results is that a firm should allocate its resources into early development stage first in order to obtain superior R D performance.
Interface Grammars for Modular Software Model Checking
Authors: Graham Hughes, Tevfik Bultan
Venue: IEEE Transactions on Software Engineering (2008)

Verification techniques relying on state enumeration (e.g., model checking) face two important challenges: the state-space explosion, an exponential increase in the state space as the number of components increases; and environment generation, modeling components that are either not available for analysis, or that cannot be handled by the verification tool in use. We propose a semi-automated approach for attacking these problems. In our approach, interfaces for the components not under analysis are specified using a specification language based on grammars. Specifically, an interface grammar for a component specifies the sequences of method invocations that are allowed by that component. We have built an compiler that takes the interface grammar for a component as input and generates a stub for that component. The stub thus generated can be used to replace that component during state space exploration, either to moderate state space explosion, or to provide an executable environment for the component under verification. We conducted a case study by writing an interface grammar for the Enterprise JavaBeans (EJB) persistence interface, and using the resulting stub to check EJB clients using the JPF model checker. Our results show that EJB clients can be verified efficiently with JPF using our approach.
An Improved Chaos-Based Stream Cipher Algorithm and its VLSI Implementation
Authors: Shubo Liu, Jing Sun, Zhengquan Xu, Zhaohui Cai
Venue: Proceedings of the 2008 Fourth International Conference on Networked Computing and Advanced Information Management - Volume 02 (2008)

Recently, the growing numbers of cryptosystems based on chaos have been proposed; many of them have good statistical properties and security but low efficiency. To increase operating efficiency of cryptosystems, an improved chaos-based stream cipher algorithm based on discrete chaotic maps is presented. The algorithm improves the complexity of chaos by randomly changing chaotic control parameter. In the proposed algorithm, one logistic chaotic system generates the random changing parameter to control the parameter of the other. The algorithm only disturbs the control parameter of the chaotic system, so the chaotic character of the system itself has not been destroyed. To implement the algorithm, its VLSI architecture with low hardware cost and fast speed is designed, and the FPGA realization is given. Finally the algorithm is simulated to demonstrate the effectiveness of the proposed architecture.
Using BioAgents for Supporting Manual Annotation on Genome Sequencing Projects
Authors: Célia Ghedini Ralha, Hugo W. Schneider, Lucas O. Fonseca, Maria Emilia Walter, Marcelo M. Brígido
Venue: Proceedings of the 3rd Brazilian symposium on Bioinformatics: Advances in Bioinformatics and Computational Biology (2008)

Enormous volume of DNA sequences of organisms are continuously being discovered by genome sequencing projects around the world. The task of identifying biological function prediction for the DNA sequences is a key activity in genome projects. This task is done in the annotation phase, which is divided into automatic and manual. The automatic annotation has the objective of finding, for each DNA sequence identified in the project, similar sequences among millions, stored in public databases, by using approximated pattern matching algorithms. The manual annotation is done by the biologists, that use the results produced by the automatic annotation, and their knowledge and experience, to decide the function prediction to each DNA sequence. In this way, the biologists guarantee accuracy and correctness to each sequence function prediction. This work presents a new version of BioAgents, a multiagent system (MAS) for supporting manual annotation. The system simulates the biologists' knowledge and experience for annotating DNA sequences in genome sequencing projects. The MAS cooperative approach, allows to create different specialized intelligent agents that, working together, suggest proper manual annotation. BioAgents was defined with a three-layer architecture using the JADE framework with a ruler-based engine (JESS). We have done experiments with real data from three different genome sequencing projects: Paracoccidioides brasilienses fungus, Paullinia cupana (guaraná) plant and Anaplasma marginale rickettsia. The produced results were encouraging, which prove the usefulness of BioAgents.
An Efficient Algorithm for the Evacuation Problem in a Certain Class of a Network with Uniform Path-Lengths
Authors: Naoyuki Kamiyama, Naoki Katoh, Atsushi Takizawa
Venue: Proceedings of the 3rd international conference on Algorithmic Aspects in Information and Management (2007)

In this paper, we consider the evacuation problem for a network which consists of a directed graph with capacities and transit times on its arcs. This problem can be solved by the algorithm of Hoppe and Tardos [1] in polynomial time. However their running time is high-order polynomial, and hence is not practical in general. Thus it is necessary to devise a faster algorithm for a tractable and practically useful subclass of this problem. In this paper, we consider a dynamic network with a single sink s such that (i) for each vertex v the sum of transit times of arcs on any path from v to s takes the same value, and (ii) for each vertex v the minimum v-s cut is determined by the arcs incident to s whose tails are reachable from v. We propose an efficient algorithm for this network problem. This class of networks is a generalization of the grid network studied in the paper [2].
Directional Interchangeability for Enhancing CSP Solving
Authors: Wady Naanaa
Venue: Proceedings of the 4th international conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems (2007)

This paper introduces directional interchangeability, a weak form of neighborhood interchangeability [6]. The basic idea is that although two values of a variable may not be neighborhood interchangeable if we consider the whole neighborhood of the variable, they could be neighborhood interchangeable if we restrict the neighborhood to a subset of neighboring variables induced by a variable ordering.In spite of the fact that the proposed concept cannot be used to remove redundant values while preserving problem satisfiability, it provides a mean to partition value domains into subsets of directionally interchangeable values that can be attempted simultaneously by a tree search.Several experiments carried out on various binary CSPs, clearly indicate that variations of the Forward-Checking algorithm and the Maintaining Arc-Consistency algorithm that exploit directional interchangeability often outperform the original algorithms.
Can Students Edit Their Learner Model Appropriately?
Authors: Susan Bull, Xiaoxi Dong, Mark Britland, Yu Guo
Venue: Proceedings of the 9th international conference on Intelligent Tutoring Systems (2008)

We investigate whether students can edit their learner model appropriately considering: (i) evidence about the model contents; (ii) accuracy of self-assessment; (iii) type of information in the model; (iv) level of knowledge.
Data Transfer in Advance on Cluster
Authors: Nilton Cézar Paula, Gisele Silva Craveiro, Liria Matsumoto Sato
Venue: Proceedings of the 9th international conference on Parallel Computing Technologies (2007)

Scientific applications are increasingly challenging computational platforms and software tools. In this scenario of improving performance demand, computer cluster users require for mechanisms that could reduce data transfer delay. To contribute to this question, we proposed a data transfer in advance mechanism that improved overall system performance by diminishing data-intensive job wait. We also designed and implemented the Integrated Scheduling System (ISS) to analyze and evaluate our proposal. This system automates the preparation, submission and tracking of job executions in a cluster. The mechanism is also combined with an I/O file operation and computation overlapping idea that results in significant improvement of performance rates, confirmed by some experiments.
Power- and Complexity-Aware Issue Queue Designs
Authors: Jaume Abella, Ramon Canal, Antonio Gonzalez
Venue: IEEE Micro (2003)

The improved performance of current microprocessors brings with it increasingly complex and power-dissipating issue logic. Recent proposals introduce a range of mechanisms for tackling this problem.
Clustering Organisms Using Metabolic Networks
Authors: Tomasz Arodź
Venue: Proceedings of the 8th international conference on Computational Science, Part II (2008)

Topological properties of metabolic networks may reflect systematic differences between evolutionary distinct groups of organisms. Indeed, the mean shortest path length between metabolites is, on average, longer in eukaryotes than in bacteria. We show that not only the averages of groups differ, but the organisms can be successfully clustered, based on network properties, into categories corresponding to taxonomic groups. We use the fact that in metabolic networks of different organisms, correspondence between vertices is available. We compare our approach with several graph indices employed previously to analyse metabolic networks, and show that they fail at achieving level of clustering similar to ours. Finally, we show that the phylogenetic tree constructed using network-based approach agrees in most cases with gene-based phylogeny.
Noetherianity and Combination Problems
Authors: Silvio Ghilardi, Enrica Nicolini, Silvio Ranise, Daniele Zucchelli
Venue: Proceedings of the 6th international symposium on Frontiers of Combining Systems (2007)

In abstract algebra, a structure is said to be Noetherian if it does not admit infinite strictly ascending chains of congruences. In this paper, we adapt this notion to first-order logic by defining the class of Noetherian theories. Examples of theories in this class are Linear Arithmetics without ordering and the empty theory containing only a unary function symbol. Interestingly, it is possible to design a non-disjoint combination method for extensions of Noetherian theories. We investigate sufficient conditions for adding a temporal dimension to such theories in such a way that the decidability of the satisfiability problem for the quantifier-free fragment of the resulting temporal logic is guaranteed. This problem is firstly investigated for the case of Linear time Temporal Logic and then generalized to arbitrary modal/temporal logics whose propositional relativized satisfiability problem is decidable.
MPI Support for Multi-core Architectures: Optimized Shared Memory Collectives
Authors: Richard L. Graham, Galen Shipman
Venue: Proceedings of the 15th European PVM/MPI Users' Group Meeting on Recent Advances in Parallel Virtual Machine and Message Passing Interface (2008)

With local core counts on the rise, taking advantage of shared-memory to optimize collective operations can improve performance. We study several on-host shared memory optimized algorithms for MPI_Bcast, MPI_Reduce, and MPI_Allreduce, using tree-based, and reduce-scatter algorithms. For small data operations with relatively large synchronization costs fan-in/fan-out algorithms generally perform best. For large messages data manipulation constitute the largest cost and reduce-scatter algorithms are best for reductions. These optimization improve performance by up to a factor of three. Memory and cache sharing effect require deliberate process layout and careful radix selection for tree-based methods.
Learning Efficiency of Very Simple Grammars from Positive Data
Authors: Ryo Yoshinaka
Venue: Proceedings of the 18th international conference on Algorithmic Learning Theory (2007)

The class of very simple grammars is known to be polynomial-time identifiable in the limit from positive data. This paper gives even more general discussion on the efficiency of identification of very simple grammars from positive data, which includes both positive and negative results. In particular, we present an alternative efficient inconsistent learning algorithm for very simple grammars.
Generating Value from Textual Discovery
Authors: Peter Jackson
Venue: Proceedings of the 7th international conference on Computational Science, Part III: ICCS 2007 (2007)

Much of the information associated with legal, financial, medical and educational domains is stored in electronic document repositories and retrievable only by full text search. The ability of publishers to enhance such documents through traditional editorial processes struggles to keep pace with the volume and variety of textual data currently available in proprietary collections and on the Web. Fortunately, text mining tools that support the automatic classification, summarization, and linking of documents can be developed and deployed cost effectively. The outcome is a more flexible and dynamic approach to meta-data generation that does a better job of supporting the searching and browsing behaviors of information consumers. This paper describes the application of text and data mining techniques to legal information in a manner that enables powerful report generation and document recommendation services.
Optimized Multipath Network Coding in Lossy Wireless Networks
Authors: Xinyu Zhang, Baochun Li
Venue: Proceedings of the 2008 The 28th International Conference on Distributed Computing Systems (2008)

Network coding has been a prominent approach to a series of problems that used to be considered intractable with traditional transmission paradigms. Recent work on network coding includes a substantial number of optimization based protocols, but mostly for wireline multicast networks. In this paper, we consider maximizing the benefits of network coding for unicast sessions in lossy wireless environments. We propose Optimized Multipath Network Coding (OMNC), a rate control and routing protocol that dramatically improves the throughput of lossy wireless networks. OMNC employs multiple paths to push coded packets to the destination, and uses the broadcast MAC to deliver packets between neighboring nodes. The coding and broadcast rate is allocated to transmitters by a distributed optimization algorithm that maximizes the advantage of path diversity while avoiding congestion. With extensive experiments on an emulation testbed, we find that OMNC achieves significant throughput improvement over traditional best path routing protocols, and existing multipath routing protocols with network coding.
Modelling of Behavioural Patterns for Abnormality Detection in the Context of Lifestyle Reassurance
Authors: Fabien Cardinaux, Simon Brownsell, Mark Hawley, David Bradley
Venue: Proceedings of the 13th Iberoamerican congress on Pattern Recognition: Progress in Pattern Recognition, Image Analysis and Applications (2008)

As a consequence of the growing number of older and vulnerable people, health and care providers are increasingly considering new approaches to support people in their own homes. In this context, lifestyle reassurance analyses data collected from a range of sensors to determine a person's `routine' and highlights any important changes. This paper proposes a new approach for detection of individual deviation from normal behaviour focusing on building probabilistic models of behaviour based on a set of activity attributes. Models are trained using only normal behaviour. Variations from the models are considered as abnormal behaviours and these can be highlighted for subsequent review or intervention. Case study experiments with real life data suggest that some users' activities follow regular patterns and that these patterns can be learned with probabilistic models.
Computing Join Aggregates over Private Tables
Authors: Rong She, Ke Wang, Ada Waichee Fu, Yabo Xu
Venue: Proceedings of the 9th international conference on Data Warehousing and Knowledge Discovery (2007)

We propose a privacy-preserving protocol for computing aggregation queries over the join of private tables. In this problem, several parties wish to share aggregated information over the join of their tables, but want to conceal the details that generate such information. The join operation presents a challenge to privacy preservation because it requires matching individual records from private tables. We solve this problem by a novel sketching protocol that securely computes some randomized summary information over private tables. It ensures that during the query computation process, no party will learn other parties' private data, including the individual records and data distributions. Previous works have not provided this level of privacy for such queries.
Measurement of voltage flicker and implementation using FPGA
Authors: Shu-Chen Wang, Yu-Jen Chen, Chi-Jui Wu
Venue: Proceedings of the 7th WSEAS International Conference on Instrumentation, Measurement, Circuits and Systems (2008)

This paper proposes a field-programmable gate array (FPGA)-based integrated circuit (IC) for measuring voltage flicker using the instantaneous voltage vectors. The proposed design scheme is developed using the very high speed integrated-circuit hardware description language (VHDL). The instantaneous voltage vector module, management module, and quantification modules are developed to construct the entire system. Some novel IP (intellectual property) cores, such as CORDIC and FFT, are used. Then the chip for voltage flicker calculation is designed based on these IP cores and is realized using a signal FPGA (XC3S1500). Some given simulation waveforms and field-measured waveforms with voltage flicker disturbances are adopted to demonstrate that the designed IC can obtain flicker components precisely.
Using Constraints over Finite Sets of Integers for Range Concatenation Grammar Parsing
Authors: Yannick Parmentier, Wolfgang Maier
Venue: Proceedings of the 6th international conference on Advances in Natural Language Processing (2008)

Range Concatenation Grammar (RCG) is a formalism with interesting formal properties (it has a polynomial parsing time while being more powerful than Linear Context-Free Rewriting Systems). In this context, we present a constraint-based extension of the state-of-the-art RCG parsing algorithm of [1], which has been used for the implementation of an open-source parsing architecture.
Half a Lifetime in Computing: Experiences in Zambia, Britain, and Australia
Authors: Valerie A. G. Macduff
Venue: IEEE Annals of the History of Computing (2003)

This brief overview tells of the author's 35 years in the computing industry. Her career began coincidentally with a move to Zambia in the 1960s, where she learned to program an IBM 1130. Following a move to Australia in 1989, she began her own computer consultancy to the geographical information community. 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
Improved Second-Order Quantifier Elimination in Modal Logic
Authors: Renate A. Schmidt
Venue: Proceedings of the 11th European conference on Logics in Artificial Intelligence (2008)

This paper introduces improvements for second-order quantifier elimination methods based on Ackermann's Lemma and investigates their application in modal correspondence theory. In particular, we define refined calculi and procedures for solving the problem of eliminating quantified propositional symbols from modal formulae. We prove correctness results and use the approach to compute first-order frame correspondence properties for modal axioms and modal rules. Our approach can solve two new classes of formulae which have wider scope than existing classes known to be solvable by second-order quantifier elimination methods.
The embodiment of cockroach aggregation behavior in a group of micro-robots
Authors: Simon Garnier, Christian Jost, Jacques Gautrais, Masoud Asadpour, Gilles Caprari, Raphaël Jeanson, Anne Grimal, Guy Theraulaz
Venue: Artificial Life (2008)

We report the faithful reproduction of the self-organized aggregation behavior of the German cockroach Blattella germanica with a group of robots. We describe the implementation of the biological model provided by Jeanson et al. in Alice robots, and we compare the behaviors of the cockroaches and the robots using the same experimental and analytical methodology. We show that the aggregation behavior of the German cockroach was successfully transferred to the Alice robot despite strong differences between robots and animals at the perceptual, actuatorial, and computational levels. This article highlights some of the major constraints one may encounter during such a work and proposes general principles to ensure that the behavioral model is accurately transferred to the artificial agents.