ppxscal/embedding_network huggingface dataset:
Fostering argumentative knowledge construction through enactive role play in Second Life
Authors: Azilawati Jamaludin, Yam San Chee, Caroline Mei Lin Ho
Venue: Computers Education (2009)

This paper examines how pre-university students shared and constructed knowledge in the context of GP (general paper) by interacting through individual virtual characters across five cycles of enactive role play sessions. Contextualized scenarios on the topic of euthanasia were developed in Second Life. Role-playing the virtual characters through three-dimensional avatars, 45 students from two different classes grappled and dealt with issues related to euthanasia such as ethics, morality, and religion. The enactment log transcripts of 10 student groups across five enactment sessions were analyzed using an adapted collaborative argumentation framework. We present the results from two types of data analysis: a macro quantitative analysis of students' enactment log transcripts and a qualitative analysis of their open-ended responses. Our quantitative analysis at the class level revealed salient differences in the nature of epistemic interactions, the patterns of argumentative moves, and the patterns of social interactions between students from two classes. The findings from the qualitative analysis of students' open-ended responses indicate that students valued the embodied experience afforded by the immersive virtual environment. We discuss the findings of our research in terms of important pedagogical implications and the factors that influence argumentative knowledge sharing and constructing activities.
Modelling and Performance Evaluation of Improved Access Mechanisms in a Novel Multiservice OPS Architecture
Authors: Thaere Eido, Ferhan Pekergin, Tülin Atmaca
Venue: Proceedings of the 8th International IFIP-TC 6 Networking Conference (2009)

Optical Packet Switching (OPS) technologies are among the most promising solutions for Next Generation Networks. In OPS networks, several mechanisms for Quality of Service (QoS) management have been developed. In this paper, we address QoS and fairness issues in a novel OPS ring architecture with a slotted synchronous transmission. The MAC protocol in the studied architecture is similar to CSMA/CA. Each node may use the available bandwidth in an opportunist manner. Therefore, the chances for each node to find available transmission resources are tightly correlated to the matrix of traffic at the other nodes. In order to remedy this problem, we elaborate two improved access mechanisms with preemptive approaches: Packet Erasing Mechanism (PEM) and Extraction and Reemission Mechanism (ERM). We evaluate the performance of the proposed mechanisms using a discrete-time analytical model. Finally, the results obtained by our model are validated and analyzed through several simulation scenarios.
Entropy bounds for perfect matchings and Hamiltonian cycles
Authors: Bill Cuckler, Jeff Kahn
Venue: Combinatorica (2009)

For a graph G = (V,E) and x: E &#x2192; &#x211c;+ satisfying &#x03a3;e&#x220b;&#x03c5; x e = 1 for each &#x03c5; &#x2208; V, set h(x) = &#x03a3;e x e log(1/x e ) (with log = log2). We show that for any n-vertex G, random (not necessarily uniform) perfect matching f satisfying a mild technical condition, and x e =Pr(e&#x2208;f), $$H(f) < h(x) - \frac{n}{2}\log e + o(n)$$ (where H is binary entropy). This implies a similar bound for random Hamiltonian cycles. Specializing these bounds completes a proof, begun in [6], of a quite precise determination of the numbers of perfect matchings and Hamiltonian cycles in Dirac graphs (graphs with minimum degree at least n/2) in terms of h(G):=max&#x03a3;e x e log(1/x e ) (the maximum over x as above). For instance, for the number, &#x03a8;(G), of Hamiltonian cycles in such a G, we have $$\Psi (G) = exp_2 [2h(G) - n\log e - o(n)].$$.
Fault injection framework for system resilience evaluation: fake faults for finding future failures
Authors: Thomas Naughton, Wesley Bland, Geoffroy Vallee, Christian Engelmann, Stephen L. Scott
Venue: Proceedings of the 2009 workshop on Resiliency in high performance (2009)

As high-performance computing (HPC) systems increase in size and complexity they become more difficult to manage. The enormous component counts associated with these large systems lead to significant challenges in system reliability and availability. This in turn is driving research into the resilience of large scale systems, which seeks to curb the effects of increased failures at large scales by masking the inevitable faults in these systems. The basic premise being that failure must be accepted as a reality of large scale system and coped with accordingly through system resilience. A key component in the development and evaluation of system resilience techniques is having a means to conduct controlled experiments. A common method for performing such experiments is to generate synthetic faults and study the resulting effects. In this paper we discuss the motivation and our initial use of software fault injection to support the evaluation of resilience for HPC systems. We mention background and related work in the area and discuss the design of a tool to aid in fault injection experiments for both user-space (application-level) and system-level failures.
Levy models and long correlations applied to the study of exchange traded funds
Authors: M. C. Mariani, J. D. Libbin, K. J. Martin, E. Ncheuguim, M. P. Beccar Varela, V. Kumar Mani, C. A. Erickson, D. J. Valles-Rosales
Venue: International Journal of Computer Mathematics (2009)

This work is devoted to the study of statistical properties of Exchange Traded Funds (ETF). Some of the leading ETF in the market are analysed by using the Hurst and DFA methods to detect long range correlations, and the Levy models to describe the return distributions. It is concluded that the statistical behaviour of the ETF is very similar to the behaviour of the corresponding financial indices that they mimic.
Event Extraction for Italian Using a Cascade of Finite-State Grammars
Authors: Vanni Zavarella, Hristo Tanev, Jakub Piskorski
Venue: Proceeding of the 2009 conference on Finite-State Methods and Natural Language Processing: Post-proceedings of the 7th International Workshop FSMNLP 2008 (2009)

This paper reports on our experience of adapting a real-world live event extraction system based on a cascade of finite-state extraction grammars to the processing of a new language, namely Italian. The real-time event extraction processing chain and the pattern specification language are briefly presented. The major part of the paper focuses on the creation of event extraction grammars and related resources for English and their adaptation for extracting events in Italian news articles. Some interesting phenomena which complicate the event extraction task for Italian are pinpointed and the results of the evaluation are presented. In particular, we compared two versions of the system for Italian, one based on surface-level patterns and a hybrid one, which integrates slightly more linguistically sophisticated patterns for covering a rich variety of morphological and syntactic constructions in Italian.
An optimal joint scheduling and drop policy for Delay Tolerant Networks
Authors: Amir Krifa, Chadi Barakat, Thrasyvoulos Spyropoulos
Venue: Proceedings of the 2008 International Symposium on a World of Wireless, Mobile and Multimedia Networks (2008)

Delay Tolerant Networks (DTN) are wireless networks where disconnections may occur frequently. In order to achieve data delivery in DTNs, researchers have proposed the use of store-carry-and-forward protocols: there, a node may store a message in its buffer and carry it along for long periods of time, until an appropriate forwarding opportunity arises. Multiple message replicas are often propagated to increase delivery probability. This combination of long-term storage and replication imposes a high storage and bandwidth overhead. Thus, efficient scheduling and drop policies are necessary to: (i) decide on the order by which messages should be replicated when contact durations are limited, and (ii) which messages should be discarded when nodes’ buffers operate close to their capacity. In this paper, we propose an efficient joint scheduling and drop policy that can optimize different performance metrics, like average delay and delivery probability. Using the theory of encounter-based message dissemination, we first propose an optimal policy based on global knowledge about the network. Then, we introduce a distributed algorithm that can approximate the performance of the optimal algorithm, in practice. Using simulations based on a synthetic mobility model and a real mobility trace, we show that our optimal policy and its distributed variant outperform existing resource allocation schemes for DTNs, such as the RAPID protocol [4], both in terms of average delivery ratio and delivery delay.
As Safe As It Gets: Near-Optimal Learning in Multi-Stage Games with Imperfect Monitoring
Authors: Danny Kuminov, Moshe Tennenholtz
Venue: Proceeding of the 2008 conference on ECAI 2008: 18th European Conference on Artificial Intelligence (2008)

We introduce the first near-optimal polynomial algorithm for obtaining the mixed safety level value of an initially unknown multi-stage game, played in a hostile environment, under imperfect monitoring. In an imperfect monitoring setting all that an agent can observe is the current state and its own actions and payoffs, but it can not observe other agents' actions. Our result holds for any multi-stage generic game with a “reset” action.
RF-Based Initialisation for Inertial Pedestrian Tracking
Authors: Oliver Woodman, Robert Harle
Venue: Proceedings of the 7th International Conference on Pervasive Computing (2009)

Location information is an important source of context for ubiquitous computing systems. We have previously developed a wearable location system that combines a foot-mounted inertial unit, a detailed building model and a particle filter to locate and track humans in indoor environments. In this paper we present an algorithm in which a map of radio beacon signal strengths is used to solve two of the major problems with the original system: scalability to large environments and uncertainty due to environmental symmetry.We show that the algorithm allows the deployment of the system in arbitrarily large buildings, and that uncertainty due to environmental symmetry is reduced. This reduction allows a user to be located after taking an average of 38 steps in a 8725 m2 three-storey building, compared with 76 steps in the original system. Finally, we show that radio maps such as those required by the algorithm can be generated quickly and automatically using the wearable location system itself. We demonstrate this by building a radio map for the 8725 m2 building in under two and a half hours.
Correctness of high-level transformation systems relative to nested conditions†
Authors: Annegret Habel, Karl-heinz Pennemann
Venue: Mathematical Structures in Computer Science (2009)

In this paper we introduce the notions of nested constraints and application conditions, short nested conditions. For a category associated with a graphical representation such as graphs, conditions are a graphical and intuitive, yet precise, formalism that is well suited to describing structural properties. We show that nested graph conditions are expressively equivalent to first-order graph formulas. A part of the proof includes transformations between two satisfiability notions of conditions, namely <private-char><inline-graphic mime-subtype="gif" xlink="S0960129508007202_char1"/></private-char>-satisfiability and <private-char><inline-graphic mime-subtype="gif" xlink="S0960129508007202_char2"/></private-char>-satisfiability. We consider a number of transformations on conditions that can be composed to construct constraint-guaranteeing and constraint-preserving application conditions, weakest preconditions and strongest postconditions. The restriction of rule applications by conditions can be used to correct transformation systems by pruning transitions leading to states violating given constraints. Weakest preconditions and strongest postconditions can be used to verify the correctness of transformation systems with respect to pre-and postconditions.
Evolutive neural fuzzy filtering: real time constrains
Authors: J. J. Medel Juárez, J. C. García Infante, J. C. Sánchez García
Venue: Proceedings of the 8th WSEAS international conference on Signal processing, robotics and automation (2009)

In this paper, we describe the evolutive neural fuzzy filtering properties with real time conditions, giving the principles of its operation based on a back propagation fuzzy neural net, which adaptively choose and emit a decision according with the reference signal changes in order to loop the correct new conditions for a process. This work is an approach about the evolutive neural fuzzy digital filters (ENFDF). This filter using the neural fuzzy mechanism select the best parameter values into the knowledge base (KB), actualizing the filter weights to give a good enough answers with respect to the reference signal in natural linguistic sense. Additionally, the filtering architecture includes a decision making stage using an inference into its structure to deduce the filter decisions in accordance with the previous and actual filter answer in order to updates the new decision with respect to the new reference system conditions. This process requires that all of its states bound into ENFDF time limit as a real time system, considering the Nyquist and Shannon criteria. In this paper, we characterize the membership functions building the knowledge base in a probabilistic way with respect to the rules set inference to describe the reference system and the inference to deduce the new filter decision, performing the ENFDF. Moreover, the paper describes in schematic sense the neural net architecture with the decision-making stages in order to integrate the filtering stages as an evolutive system. The results expressed in formal sense using the concepts into the paper references. Finally, we present the simulation of the ENFDF operation using the Matlab© software. The paper has eight sections conformed as follows: 1. Introduction, 2. Filtering conditions, 3. Neural net description, 4. Rule base strategy, 5. Real time scheme, 6. Simulations, 7.Conclusion and References.
Legal rules and argumentation in a metalogic framework
Authors: Jenny Eriksson Lundström, Jørgen Fischer Nilsson, Andreas Hamfelt
Venue: Proceeding of the 2007 conference on Legal Knowledge and Information Systems: JURIX 2007: The Twentieth Annual Conference (2007)

In this paper we show how to address legal argumentation as a dialectic process using a metalogic defeasible framework. We provide a formal model in which, the argumentation of the parties can be analyzed computationally. Further we argue that the accommodation of legal reasoning by using hierarchical defeasible theories of [7] provides a comprehensive alternative for constructing legally acceptable and meaningful theories of case-adapted jurisprudence with the purpose of facilitating legal audits and the preparation of appeals to a higher tribunal.
Learning from actions not taken: a multiagent learning algorithm
Authors: Newsha Khani, Kagan Tumer
Venue: Proceedings of The 8th International Conference on Autonomous Agents and Multiagent Systems - Volume 2 (2009)

Learning in multiagent systems is generally slow because the agent has to extract its correct policy through not only through its interaction with the environment, but also from its interactions with other learning agents. In this paper, we present an approach that significantly improves the learning speed in multiagent systems by allowing an agent to up-date its estimate of the rewards for all its available actions, not just the action that was taken. Our results show that the rewards on such "actions not taken" are beneficial early in training, particularly when agent teams are leveraged to estimate those rewards.
Towards auction algorithms for large dense assignment problems
Authors: Libor Buš, Pavel Tvrdík
Venue: Computational Optimization and Applications (2009)

In this paper, we focus on the problem of solving large-scale instances of the linear sum assignment problem by auction algorithms. We introduce a modified auction algorithm, called look-back auction algorithm, which extends the forward auction algorithm by the ability of reusing information from previous bids. We show that it is able to reuse information from the previous bids with high efficiency for all tested types of input instances. We discuss then the design and implementation of a suite of sequential and distributed memory auction algorithms on a Linux cluster with the evaluation on several types of input instances of the linear sum assignment problem. Our results show that the look-back auction algorithm solves sequentially nearly all types of dense instances faster than other evaluated algorithms and it is more stable than the forward-reverse auction algorithm for sparse instances. Our distributed memory auction algorithms are fully memory scalable.
Using Lagrangian Relaxation to Compute Capacity-Dependent Bid Prices in Network Revenue Management
Authors: Huseyin Topaloglu
Venue: Operations Research (2009)

We propose a new method to compute bid prices in network revenue management problems. The novel aspect of our method is that it explicitly considers the temporal dynamics of the arrivals of the itinerary requests and generates bid prices that depend on the remaining leg capacities. Our method is based on relaxing certain constraints that link the decisions for different flight legs by associating Lagrange multipliers with them. In this case, the network revenue management problem decomposes by the flight legs, and we can concentrate on one flight leg at a time. When compared with the so-called deterministic linear program, we show that our method provides a tighter upper bound on the optimal objective value of the network revenue management problem. Computational experiments indicate that the bid prices obtained by our method perform significantly better than the ones obtained by standard benchmark methods.
Global Optimization for Generalized Geometric Programs with Mixed Free-Sign Variables
Authors: Han-Lin Li, Hao-Chun Lu
Venue: Operations Research (2009)

Many optimization problems are formulated as generalized geometric programming (GGP) containing signomial terms f(X)·g(Y), where X and Y are continuous and discrete free-sign vectors, respectively. By effectively convexifying f(X) and linearizing g(Y), this study globally solves a GGP with a lower number of binary variables than are used in current GGP methods. Numerical experiments demonstrate the computational efficiency of the proposed method.
Reasoning about knowledge of unawareness revisited
Authors: Joseph Y. Halpern, Leandro C. Rêgo
Venue: Proceedings of the 12th Conference on Theoretical Aspects of Rationality and Knowledge (2009)

In earlier work [Halpern and R&ecirc;go 2006b], we proposed a logic that extends the Logic of General Awareness of Fagin and Halpern [1988] by allowing quantification over primitive propositions. This makes it possible to express the fact that an agent knows that there are some facts of which he is unaware. In that logic, it is not possible to model an agent who is uncertain about whether he is aware of all formulas. To overcome this problem, we keep the syntax of the earlier paper, but allow models where, with each world, a possibly different language is associated. We provide a sound and complete axiomatization for this logic and show that, under natural assumptions, the quantifier-free fragment of the logic is characterized by exactly the same axioms as the logic of Heifetz, Meier, and Schipper [2008].
Modeling Fuzzy DEA with Type-2 Fuzzy Variable Coefficients
Authors: Rui Qin, Yankui Liu, Zhiqiang Liu, Guoli Wang
Venue: Proceedings of the 6th International Symposium on Neural Networks: Advances in Neural Networks - Part II (2009)

Data envelopment analysis (DEA) is an effective method for measuring the relative efficiency of a set of homogeneous decision-making units (DMUs). However, the data in traditional DEA model are limited to crisp inputs and outputs, which cannot be precisely obtained in many production processes or social activities. This paper attempts to extend the traditional DEA model and establishes a DEA model with type-2 (T2) fuzzy inputs and outputs. To establish this model, we first propose a reduction method for T2 fuzzy variables based on the expected value of fuzzy variable. After that, we establish a DEA model with the obtained fuzzy variables. In some special cases such as the inputs and outputs are independent T2 triangular fuzzy variables, we provide a method to turn the original DEA model to its equivalent one. At last, we provide a numerical example to illustrate the efficiency of the proposed DEA model.
Performance Evaluation for Japanese HPF Compilers with Special Benchmark Suite
Authors: Hitoshi Sakagami, Shingo Furubayashi
Venue: Proceedings of the 4th International Symposium on High Performance Computing (2009)

The lack of performance portability has been disheartening scientific application users to develop portable programs written in HPF. As the users would like to run the same source code on different parallel machines as fast as possible, we have investigated the performance portability for Japanese HPF compilers (NEC and Fujitsu) with a special benchmark suite. We got good performance in most cases with DISTRIBUTE and INDEPENDENT directives on NEC SX-5, but Fujitsu VPP800 required to explicitly force no communication inside parallel loops with additional LOCAL directives. It was also found that manual optimizations for communication with HPF/JA extensions were very useful to tune parallel performance.
A theoretical and empirical analysis of a TTCN-3 coupling metric
Authors: M. S. Aboutrab, S. Counsell, T. Hall
Venue: Proceedings of the 2nd conference on European computing conference (2008)

Testing and Test Control Notation (TTCN-3) is a testing language for test suite specification. A Template Coupling Metric (TCM) was recently proposed by Zeiss et al. for measuring the degree of template coupling in TTCN-3 test suites. In this paper, we validate the TCM against validation criteria (both theoretical and empirical). The former was achieved through applying a set of validation properties - the latter by running experiments against a large TTCN-3 file. Results suggest that the TCM did not satisfy the majority of the theoretical validation properties and showed various flaws empirically. As such, the TCM may not useful in extracting the degree of template coupling and should be modified to improve its characteristics.