ppxscal/embedding_network huggingface dataset:
Linearized Initialization of the Newton Krylov Algorithm for Nonlinear Elliptic Problems
Authors: Sanjay Kumar Khattri
Venue: Proceedings of the 8th international conference on Computational Science, Part I (2008)

It is known that the Newton Krylov algorithm may not always converge if the initial assumption or initialization is far from the exact solution. We present a technique for initializing Newton Krylov solver for nonlinear elliptic problems. In this technique, initial guess is generated by solving linearised equation corresponding to the nonlinear equation. Here, nonlinear part is replaced by the equivalent linear part. Effectiveness of the technique is presented through numerical examples. 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
Multi-agent Reflection in Autonomic Systems
Authors: Jan Tožička, Michal Pĕchouček, Martin Rehák, Magdalena Prokopová
Venue: Proceedings of the 3rd international conference on Industrial Applications of Holonic and Multi-Agent Systems: Holonic and Multi-Agent Systems for Manufacturing (2007)

Increasing complexity and scales of computing systems bring growing demands on their designers and administrators. These issues have been explored from different viewpoints. While the multi-agent system researchers focus on the coordination and theoretic properties of distributed system, the researchers from the field of autonomic computing focus on the deployment of self-adapting systems in real domains. This contribution tries to bring together both domains and presents the multi-agent reflection from the autonomic computing point of view.We show that proposed architecture of reflective agent covers all the characteristics of an autonomic computing system and furthermore, we describe some properties of reflective agents that can further extend the autonomic computing system, especially its self-optimizing abilities. All the characteristics of autonomic computing system are demonstrated on three use cases, where the reflective agents have been deployed, together with the results of experiments.
VisGenome and Ensembl: Usability of Integrated Genome Maps
Authors: Joanna Jakubowska, Ela Hunt, John Mcclure, Matthew Chalmers, Martin Mcbride, Anna F. Dominiczak
Venue: Proceedings of the 5th international workshop on Data Integration in the Life Sciences (2008)

It is not always clear how best to represent integrated data sets, and which application and database features allow a scientist to take best advantage of data coming from various information sources. To improve the use of integrated data visualisation in candidate gene finding, we carried out a user study comparing an existing general-purpose genetics visualisation and query system, Ensembl, to our new application, VisGenome. We report on experiments verifying the correctness of visual querying in VisGenome, and take advantage of software assessment techniques which are still uncommon in bioinformatics, including asking the users to perform a set of tasks, fill in a questionnaire and participate in an interview. As VisGenome offers smooth zooming and panning driven by mouse actions and a small number of search and view adjustment menus, and Ensembl offers a large amount of data in query interfaces and clickable images, we hypothesised that a simplified interface supported by smooth zooming will help the user in their work. The user study confirmed our expectations, as more users correctly completed data finding tasks in VisGenome than in Ensembl. This shows that improved interactivity and a novel comparative genome representation showing data at various levels of detail support correct data analysis in the context of cross-species QTL and candidate gene finding. Further, we found that a user study gave us new insights and showed new challenges in producing tools that support complex data analysis scenarios in the life sciences.
A Self-organising Network Based on Lightweight Agents
Authors: John Debenham, Ante Prodan
Venue: Proceedings of the 2nd international conference on Network-Based Information Systems (2008)

A lightweight multiagent system is deployed at each node in a communications network with the aim of self-organising the network as usage alters. The distributed, light-weight, co-operative multiagent system guarantees scalability of the approach. As the solution is distributed it is unsuitable to achieve any global optimisation goal -- it simply seeks to continually improve network performance as demands change. Algorithms are described for adjusting the communication channels and for adjusting the network links. Experiments show that the method is robust and delivers good performance.
Localized approach to handling network failures
Authors: Srihari Nelakuditi
Venue:  (2007)

Five nines availability is being expected from IP networks due to the growing popularity of IP telephony and the increasing usage of the Internet for mission-critical applications. This necessitates enhancing the resiliency of IP networks against transient failures that are observed to happen relatively frequently even in well-managed networks. Static broadband wireless networks, due to their ease of deployment, are likely to proliferate in the near future. The major stumbling block, however, is that wireless links are prone to external interference, channel fading, inclement weather, etc. Therefore scalable and reliable routing despite frequent link quality fluctuations is needed for accelerating the growth of these networks. Traditional link state based routing schemes require global link state advertisements to handle failures and thus can incur long delay and large overhead. Localized approaches, on the other hand, provide local protection against the failures by suppressing the failure notification and therefore can react faster to failures. They also reduce overhead of control traffic triggered by global advertisement of link state. However, a naive localized approach can cause routers to have different views of the network topology and thus result in forwarding loops and packet drops. This dissertation proposes three localized schemes for wired and wireless networks to handle network disruptions: Failure Inferencing based Fast Rerouting (FIFR), Localized On-demand Link State (LOLS) routing and Blacklist-based Interface Specific Forwarding (BISF). FIFR applies to wired networks and guarantees protection against any single failure of intra-AS or inter-AS, link or node, in a network with point-to-point or multi-access links with symmetric or asymmetric weights. Designed specially for wireless networks, LOLS propagates link states on-demand and to the scope as far as necessary. It ensures loop-free delivery of packets to all reachable destinations regardless of the number of disruptions in the network. Motivated by FIFR, and LOLS, BISF is designed for a wired network that combines the features of the two schemes. It provides loop-free delivery of packets to most destinations even under multiple simultaneous failures.
Unimanual and Bimanual Weight Discrimination in a Desktop Setup
Authors: Christos Giachritsis, Alan Wing
Venue: Proceedings of the 6th international conference on Haptics: Perception, Devices and Scenarios (2008)

There is evidence that weight perception with one hand may be based on integrating effort signals resulting from muscular activity to support arm and weight against gravity [1]. When lifting an object with both hands, the magnitude of effort signals due to supporting the arms and weight against gravity may change in opposite ways: posture effort signals may increase due to the employment of both hands while weight effort signals may decrease due to sharing the weight between the two hands. Here, we report preliminary results of a study in which participants judged the heaviness of weights lifted with one and two hands. It was found that a weight lifted with both hands felt lighter than equal weights lifted with the left or right hand. However, unimanually lifted weights did not feel twice as heavy as bimanually lifted weights. This may suggest that an imperfect integration of both postural and weight signals could be taken into account when judging weight bimanually.
Secure Dynamic Network Reprogramming Using Supplementary Hash in Wireless Sensor Networks
Authors: Kwangkyu Park, Jonghyup Lee, Taekyoung Kwon, Jooseok Song
Venue: Proceedings of the 4th international conference on Ubiquitous Intelligence and Computing (2007)

Wireless Sensor Networks (WSNs) consist of highly resource constrained sensor nodes. A large number of sensor nodes are deployed over a wide geographical area and operate in unattended fashions. These features of WSNs make difficult the manual intervention through physical access. Thus, secure network reprogramming is a critical requirement for WSNs. So far, the previous studies have focused only on the authenticity and integrity of program images. However, the delayed authentication problem caused by the packet loss should be considered. In this paper, we propose two schemes in the way of providing the recovery method for verification processes at packet loss, using supplementary hashing: Redundant Hash scheme and Page Digest scheme. Our schemes show improved performance than previous studies.
On a Novel Dynamic Parallel Hardware Architecture for Lifting-Based DWT
Authors: Sami Khanfir, Mohamed Jemni
Venue: Proceedings of the 14th international Euro-Par conference on Parallel Processing (2008)

A novel fast scheme for Discrete Wavelet Transform (DWT) was introduced in last years under the name of lifting scheme [4, 7]. This new scheme presents many advantages over the convolution-based approach [3, 7]. For instance it is very suitable for parallelization. In this paper we present two new parallel FPGA-based implementations of the lifting-based DWT scheme. The first implementation uses pipelining, parallel processing and data reuse to increase the speed up of the algorithm. In the second architecture a controller is introduced to dynamically deploy a suitable number of clones accordingly to the available hardware resources on a targeted environment. These two architectures are able of processing large size incoming images or multi-framed images in real-time. The simulations driven on a Xilinx Virtex-5 FPGA environment has proven the practical efficiency of our contribution: the first architecture has given an operating frequency of 289 MHz, and the second demonstrated the controller's capabilities of deploying the maximum number of clones from the available resources, over a targeted FPGA environment and processing the task in parallel.
Application of geographic information systems and stochastic methods in the research of global changes
Authors: Pavel Stoynov
Venue: Proceedings of the 10th WSEAS International Conference on Mathematical Methods and Computational Techniques in Electrical Engineering (2008)

Maps have traditionally been used to explore the Earth and to exploit its resources. GIS technology, as an expansion of cartographic science, has enhanced the efficiency and analytic power of traditional mapping. Now, as the scientific community recognizes the environmental consequences of human activity, GIS technology is becoming an essential tool in the effort to understand the process of global change. GIS and the statistical methods included in them will become more and more important not only for the research of the global changes on planets and partially on the Earth but will also enter more and more deeply into the every-day life of the human community.
Towards State Space Reduction Based on T-Lumpability-Consistent Relations
Authors: Marco Bernardo
Venue: Proceedings of the 5th European Performance Engineering Workshop on Computer Performance Engineering (2008)

Markovian behavioral equivalences can be exploited for state space reduction before performance evaluation takes place. It is known that Markovian bisimilarity corresponds to ordinary lumpability and that Markovian testing and trace equivalences correspond to a coarser exact relation we call T-lumpability. While there exists an ordinary-lumpability-consistent aggregation algorithm, this is not the case with T-lumpability. Based on the axiomatization of Markovian testing and trace equivalences, we provide a sufficient condition for T-lumpability that can easily be embedded in the aggregation algorithm for ordinary lumpability, thus enhancing the potential for exact state space reduction. We also identify a class of systems --- those providing incremental services --- for which the resulting aggregation algorithm turns out to be useful.
Multi-agent approach to network intrusion detection
Authors: Martin Rehak, Michal Pechoucek, Pavel Celeda, Vojtech Krmicek, Martin Grill, Karel Bartos
Venue: Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems: demo papers (2008)

Our demo presents an agent-based intrusion detection system designed for deployment on high-speed backbone networks. The major contribution of the system is the integration of several anomaly detection techniques by means of collective trust modeling within a group of collaborative detection agents, each featuring a specific detection algorithm. The principal role of anomalies is to provide the input into the trust modeling stage of the detection, where each agent determines the flow trustfulness from aggregated anomalies. The aggregation is performed by extended trust models that model the trustfulness of generalized situated identities, represented by a set of observable features. The system is based on traffic statistics in NetFlow format acquired by dedicated hardware-accelerated network cards, and is able to perform a real-time surveillance of the gigabit networks.
Fast Point Decompression for Standard Elliptic Curves
Authors: Billy Bob Brumley, Kimmo U. Järvinen
Venue: Proceedings of the 5th European PKI workshop on Public Key Infrastructure: Theory and Practice (2008)

Many standard elliptic curves (e.g. NIST, SECG, ANSI X9.62, WTLS, ...) over the finite field $\mathbb{F}_p$ have p a prime of Mersenne-like form--this yields faster field arithmetic. Point compression cuts the storage requirement for points (public keys) in half and is hence desirable. Point decompression in turn involves a square root computation. Given the special Mersenne-like form of a prime, in this paper we examine the problem of efficiently computing square roots in the base field. Although the motivation comes from standard curves, our analysis is for fast square roots in any arbitrary Mersenne-like prime field satisfying $p \equiv 3 \pmod 4$. Using well-known methods from number theory, we present a general strategy for fast square root computation in these base fields. Significant speedup in the exponentiation is achieved compared to general methods for exponentiation. Both software and hardware implementation results are given, with a focus on standard elliptic curves.
Identification of Errors-in-Variables Systems via Extended Compensated Least Squares for the Case of Coloured Output Noise
Authors: Tomasz Larkowski, Jens G. Linden, Benoit Vinsonneau, Keith J. Burnham
Venue: Proceedings of the 2008 19th International Conference on Systems Engineering (2008)

The paper deals with the identification of dynamic discrete-time linear time-invariant errors-in-variables systems for the case of coloured output noise. The proposed algorithm is constructed within an extended bias compensated least squares framework, where the principle of the bilinear parametrisation is exploited. Two standard least squares methods are utilised to separately determine, firstly, the system parameter vector and, secondly, the input measurement noise variance together with auto-correlation elements of the output noise. Since it is based on the least squares technique, the computational complexity of the algorithm is relatively low. A Monte-Carlo simulation compares the developed technique with other errors-in-variables identification methods.
Exploring Social Dynamics in Online Bookmarking Systems
Authors: Xiaolong Zheng, Huiqian Li, Aaron Sun
Venue: Proceedings of the IEEE ISI 2008 PAISI, PACCF, and SOCO international workshops on Intelligence and Security Informatics (2008)

Web 2.0 technologies have spawned different types of information sharing systems, including online bookmarking systems. These information sharing systems have facilitated collaboration among their users with similar interests. They also provide a powerful means of sharing, organizing, and finding contents and contacts [1]. In this paper we focus on evaluating social interaction among users on Del.icio.us, which is one of the most popular and paradigmatic online bookmarking systems.
Remote labs in the online environment: indicators for success
Authors: Jack P. Krichen, Hilmi Lahoud
Venue: Proceedings of the 9th ACM SIGITE conference on Information technology education (2008)

Currently, there are several techniques used to provide hands-on educational experiences to online learners including remote labs that access physical hardware in real-time, simulation software, and virtual labs which offer a more structured environment including simulations and scheduled asynchronous access to physical resources. This study investigates how these methods can be used from the learner's perspective to enhance the distance learning experience by improving its effectiveness and maintain students' satisfaction while keeping the same level of standards and outcomes as face-to-face courses. Current online learners were surveyed to evaluate their experiences and assess their preferences for learning through teaching techniques utilizing remote labs. Survey results are used to recommend best implementation practices utilizing these techniques and to guide future studies in these methods.
A Corpus-Based Computational Model of Metaphor Understanding Incorporating Dynamic Interaction
Authors: Asuka Terai, Masanori Nakagawa
Venue: Proceedings of the 18th international conference on Artificial Neural Networks, Part II (2008)

The purpose of this study is to construct a computational model of metaphor understanding based on statistical corpora analysis. The constructed model consists of two processes: a categorization process and a dynamic interaction process. The model expresses features based not only on adjectives but also on verbs using adjective-noun and three types of verb-noun modification data. The dynamic interaction is realized based on a recurrent neural network employing differential equations. Generally, in recurrent neural networks, differential equations are converged using a sigmoid function. However, it is difficult to compare the estimated meaning of the metaphor to the estimated meaning of the target which is represented with conditional probabilities computed through statistical language analysis. In the present model, the differential equations converge over time, which makes it possible to compare the estimated meaning. Accordingly, the constructed model is able to highlight the emphasized features of a metaphorical expression. Finally, a psychological experiment is conducted in order to verify the psychological validity of the constructed model of metaphor understanding. The results from the psychological experiment support the constructed model.
Sequential decision making in repeated coalition formation under uncertainty
Authors: Georgios Chalkiadakis, Craig Boutilier
Venue: Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems - Volume 1 (2008)

The problem of coalition formation when agents are uncertain about the types or capabilities of their potential partners is a critical one. In [3] a Bayesian reinforcement learning framework is developed for this problem when coalitions are formed (and tasks undertaken) repeatedly: not only does the model allow agents to refine their beliefs about the types of others, but uses value of information to define optimal exploration policies. However, computational approximations in that work are purely myopic. We present novel, non-myopic learning algorithms to approximate the optimal Bayesian solution, providing tractable means to ensure good sequential performance. We evaluate our algorithms in a variety of settings, and show that one, in particular, exhibits consistently good sequential performance. Further, it enables the Bayesian agents to transfer acquired knowledge among different dynamic tasks.
A New Approach to Estimate Fractal Dimension of Texture Images
Authors: André R. Backes, Odemir M. Bruno
Venue: Proceedings of the 3rd international conference on Image and Signal Processing (2008)

One of the most important visual attributes for image analysis and pattern recognition is the texture. Its analysis allows to describe and identify different regions in the image through pixel organization, performing a better image description and classification. This paper presents a novel approach for texture analysis, based on calculation of the fractal dimension of binary images generated from a texture, using different threshold values. The proposed approach performs a complexity analysis as the threshold values changes, producing a texture signature which is able to characterize efficiently different texture classes. The paper illustrates the novel method performance on an experiment using Brodatz images.
Detection of Separation in S-duct Diffusers using Shear Sensitive Liquid Crystals
Authors: A. M. Pradeep, R. K. Sullerey
Venue: Journal of Visualization (2004)

In the present experimental investigation, shear sensitive liquid crystals have been successfully used to study the flow characteristics and detect separation in two-dimensional Sduct diffusers of different curvatures. Tapered-fin vortex generators in two different orientations were used to control flow separation that was observed on one of the curved walls of the diffuser. The results were verified by conventional oil flow visualization technique and excellent agreement was observed. In addition to visualization, detailed measurements that included wall static pressure, skin friction, diffuser exit total pressure and velocity distributions were taken in a uniform inlet flow with Reynolds number of 3.49 &times; 10$^5$. These results are presented here in terms of skin friction distribution, distortion and total pressure loss coefficients. The extent of the separation zone (in terms of intensity of red distribution) in the diffuser with and without vortex generators (in both configurations) compared well with the Preston tube measurements. The present study demonstrates that shear sensitive liquid crystals can be efficiently used to study the flow physics in complex internal flows. In addition, the results also indicate that shear sensitive liquid crystals can be effectively used not only as flow visualization tool but also to gain quantitative information about the flow field in internal flows.
A Systematic Approach for the Design of RFID Implementations in the Supply Chain
Authors: Cleopatra Bardaki, Angeliki Karagiannaki, Katerina Pramatari
Venue: Proceedings of the 2008 Panhellenic Conference on Informatics (2008)

This paper presents a step-by-step approach to design "realistic" RFID-enabled application scenarios and services in terms of two decision variables. The first one lies in the aspect of technical feasibility; that is to decide on technical issues (e.g. the location of the RFID readers) and the second one includes a cost-benefit assessment; that is to recognise the extent to which the potential benefits gained from RFID outweigh the value of investment and suggest a cost-effective implementation. To better illustrate the approach, the paper describes work undertaken for the design of the dynamic pricing service, relying on RFID technology in order to monitor a product’s expiration date and dynamically adjust its price.