ppxscal/embedding_network huggingface dataset:
Dynamics and flight control of the UAV formations
Authors: Teodor-Viorel Chelaru, Valentin Pana, Adrian Chelaru
Venue: WSEAS Transactions on Systems and Control (2009)

The purpose of this paper is to describe the flight of an Unmanned Aerial Vehicles (UAV) formation by using a 6 degrees of freedom (6 DOF) models. The problem of flight formation will be approached in a simple manner, by using a 3 DOF models, as well as using the complex equations that describe the movement of the 6 DOF for UAV. This theoretical development allows us to define a control structure based on direct commands, which is useful in practical applications. The work will present and analyze the calculus results for each developed solution. The novelty of this paper consists in the definition and testing of some practical solutions for an algorithm that can control an UAV formation. This algorithm allows decrypting the flight of a single UAV, as well as the entire formation. The conclusions will focus the practical possibility of implementing such algorithm on a UAV formation.
Design of anti-GPS for reasons of security
Authors: Hazem M. El-Bakry, Nikos Mastorakis
Venue: Proceedings of the international conference on Computational and information science 2009 (2009)

In this paper, the design considerations of Global Positioning System (GPS) is presented. Simulation issues related to implementing a GPS jamming signal in a laboratory test environment are introduced. These issues pertain to jamming accuracy requirements. Furthermore, important design parameters that may affect jamming system performance are discussed. In addition, an example of the Navigation Laboratory jamming system is given. It addresses fabrication issues, data requirements, error handling, local and remote operations, and how to attain high accuracy and repeatability during the generation and measurement of jamming. Moreover, a new approach for fast detection of GPS signal is presented. The entire data are collected together in a long vector and then tested as a one input pattern. Proposed fast time delay neural networks (FTDNNs) use cross correlation in the frequency domain between the tested data and the input weights of neural networks. It is proved mathematically and practically that the number of computation steps required for the presented time delay neural networks is less than that needed by conventional time delay neural networks (CTDNNs). Simulation results using MATLAB confirm the theoretical computations.
GP-BayesFilters: Bayesian filtering using Gaussian process prediction and observation models
Authors: Jonathan Ko, Dieter Fox
Venue: Autonomous Robots (2009)

Bayesian filtering is a general framework for recursively estimating the state of a dynamical system. Key components of each Bayes filter are probabilistic prediction and observation models. This paper shows how non-parametric Gaussian process (GP) regression can be used for learning such models from training data. We also show how Gaussian process models can be integrated into different versions of Bayes filters, namely particle filters and extended and unscented Kalman filters. The resulting GP-BayesFilters can have several advantages over standard (parametric) filters. Most importantly, GP-BayesFilters do not require an accurate, parametric model of the system. Given enough training data, they enable improved tracking accuracy compared to parametric models, and they degrade gracefully with increased model uncertainty. These advantages stem from the fact that GPs consider both the noise in the system and the uncertainty in the model. If an approximate parametric model is available, it can be incorporated into the GP, resulting in further performance improvements. In experiments, we show different properties of GP-BayesFilters using data collected with an autonomous micro-blimp as well as synthetic data.
Shape Recovery of Specular Surface Using Color Highlight Stripe and Light Source Coding
Authors: Yankui Sun, Chengkun Xue, Masatoshi Kimachi, Masaki Suwa
Venue: Proceedings of the 4th International Conference on Computer Vision/Computer Graphics CollaborationTechniques (2009)

Shape recovery of specular surface is a challenging task; camera images of these surfaces are difficult to interpret because they are often characterized by highlights. Structured Highlight approach is a classic and effective way for specular inspection, this paper suggests a new strategy to recover dense normals of a specular surface and reconstruct its shape by combining the ideas of Structured Highlight, color source coding, highlight stripe and its translations. Point sources with different colors are positioned on orbits to illuminate a specular object surface. These point sources are scanned, and highlights on the object surface resulting from each point source are used to derive local surface orientation. Dense normal information can be recovered by translating these orbits. Some experimental system configurations are given. The simulation results show that the new method is feasible and can be used to reconstruct shape of specular surface in a high precision.
Efficient parallel Text Retrieval techniques on Bulk Synchronous Parallel (BSP)/Coarse Grained Multicomputers (CGM)
Authors: Charalampos Konstantopoulos, Basilis Mamalis, Grammati Pantziou, Damianos Gavalas
Venue: The Journal of Supercomputing (2009)

In this paper, we present efficient, scalable, and portable parallel algorithms for the off-line clustering, the on-line retrieval and the update phases of the Text Retrieval (TR) problem based on the vector space model and using clustering to organize and handle a dynamic document collection. The algorithms are running on the Coarse-Grained Multicomputer (CGM) and/or the Bulk Synchronous Parallel (BSP) model which are two models that capture within a few parameters the characteristics of the parallel machine. To the best of our knowledge, our parallel retrieval algorithms are the first ones analyzed under these specific parallel models. For all the phases of the proposed algorithms, we analytically determine the relevant communication and computation cost thereby formally proving the efficiency of the proposed solutions. In addition, we prove that our technique for the on-line retrieval phase performs very well in comparison to other possible alternatives in the typical case of a multiuser information retrieval (IR) system where a number of user queries are concurrently submitted to an IR system. Finally, we discuss external memory issues and show how our techniques can be adapted to the case when processors have limited main memory but sufficient disk capacity for holding their local data.
Keynote lecture 3: compilation and optimization for high performance computing
Authors: Kleanthis Psarris
Venue: Proceedings of the 15th american conference on Applied mathematics (2009)

High end parallel and multi-core processors rely on compilers to perform the necessary optimizations and exploit concurrency in order to achieve higher performance. However, source code for high performance computers is extremely complex to analyze and optimize. In particular, program analysis techniques often do not take into account complex expressions during the data dependence analysis phase. Most data dependence tests are only able to analyze linear expressions, even though non-linear expressions occur very often in practice. Therefore, considerable amounts of potential parallelism remain unexploited. In this talk we propose new data dependence analysis techniques to handle such complex instances of the dependence problem and increase program parallelization. Our method is based on a set of polynomial time techniques that can prove or disprove dependences in source codes with non-linear and symbolic expressions, complex loop bounds, arrays with coupled subscripts, and if-statement constraints. In addition our algorithm can produce accurate and complete direction vector information, enabling the compiler to apply further transformations. To validate our method we performed an experimental evaluation and comparison against the I-Test, the Omega test and the Range test in the Perfect and SPEC benchmarks. The experimental results indicate that our dependence analysis tool is accurate, efficient and more effective in program parallelization than the other dependence tests. The improved parallelization results into higher speedups and better program execution performance in several benchmarks.
The Power of Non-deterministic Reassignment in Infinite-Alphabet Pushdown Automata
Authors: Yulia Dubov, Michael Kaminski
Venue: Languages: From Formal to Natural: Essays Dedicated to Nissim Francez on the Occasion of His 65th Birthday (2009)

In this paper we compare two models of pushdown automata over infinite alphabets, one with non-deterministic reassignment and the other with the deterministic one, and show that the former model is stronger than the latter.
An outline of the three-layer survivability analysis architecture for strategic information warfare research
Authors: Zhanshan (Sam) Ma, Axel W. Krings, Frederick T. Sheldon
Venue: Proceedings of the 5th Annual Workshop on Cyber Security and Information Intelligence Research: Cyber Security and Information Intelligence Challenges and Strategies (2009)

We apply the three-layer survivability analysis architecture developed by Ma & Krings (Ma & Krings 2009, Ma 2008) in the context of distributed networks (such as wireless sensor networks) to the study of strategic information warfare. To simplify the research problem, we assume that the information warfare (IW) is conducted in an isolated paradigm, which we call an electronic cosmos (e-cosmos), i.e., independent of other national and/or war strategies, which is not realistic but allows us to develop a manageable mathematical architecture for modeling and simulation. In this architecture issues outside the cosmos, such as other national or war strategies, are abstracted and represented with the vectors of environmental covariates. This architecture integrates four closely related fields: reliability analysis, survivability analysis, dynamic hybrid fault models, and agent-based computing under a unified architecture. Analogically, it draws on biological inspiration from the studies on metapopulation dynamics, animal communication networks and conflict resolution, social learning and social foraging in behavioral and cognitive ecology. Mathematically, the architecture consists of three layers and is formulated around the core concept of dynamic hybrid fault models---the notion of "Byzantine generals playing the evolutionary game." The three-layer architecture includes a set of definitions, models and approaches: The tactical level deals with unpredictable, latent, unobserved or unobservable risks (UUUR) by utilizing survival analysis and its sister technologies. The strategic level integrates dynamic hybrid fault models (Ma & Krings 2008, Ma 2008) and tactical level models. From the strategic level, the evolutionary stable strategy (ESS) prescribes the sustainable or survivable strategies. In the third level---operational level---a duo of survivability metrics, action threshold survivability (TS) and the expected survivability (ES), are defined to help implement the survivable strategies. This new approach requires neither the knowledge of the probabilities of UUUR events nor the assignment of subjective probabilities. In addition, we subscribe to Deibel's (2007) concept of hierarchical strategies and consider IW strategy as simply a layer in a multi-layer structure of the national strategy. Due to the generalities of the mathematical approaches adopted in the architecture and of the architecture itself, the methodology we develop (temporality termed enhanced evolutionary game theory) may be applied to an expanded cosmos---when the strategic IW is put into a larger context such as warfare strategy.1
Passivity Analysis of Neural Networks with Time-Varying Delays of Neutral Type
Authors: Jianqin Wang, Qiankun Song
Venue: Proceedings of the 6th International Symposium on Neural Networks on Advances in Neural Networks (2009)

In this paper, the passivity is investigated for neural networks with time-varying delays of neutral type and generalized activation functions. By using Lyapunov method, Newton-Leibniz formulation and linear matrix inequality (LMI) technique, several delay-independent sufficient conditions in LMI are obtained to guarantee the passivity of the addressed neural networks. The proposed passivity criteria do not require the monotonicity of the activation functions and the differentiability of the time-varying delays, which means that our results generalize and further improve those in the earlier publications. An example is given to show the effectiveness and less conservatism of the obtained conditions.
Cartograms, Self-Organizing Maps, and Magnification Control
Authors: Roberto Henriques, Fernando Bação, Victor Lobo
Venue: Proceedings of the 7th International Workshop on Advances in Self-Organizing Maps (2009)

This paper presents a simple way to compensate the magnification effect of Self-Organizing Maps (SOM) when creating cartograms using Carto-SOM. It starts with a brief explanation of what a cartogram is, how it can be used, and what sort of metrics can be used to assess its quality. The methodology for creating a cartogram with a SOM is then presented together with an explanation of how the magnification effect can be compensated in this case by pre-processing the data. Examples of cartograms produced with this method are given, concluding that Self-Organizing Maps can be used to produce high quality cartograms, even using only standard software implemen-tations of SOM.
A survey of computational location privacy
Authors: John Krumm
Venue: Personal and Ubiquitous Computing (2009)

This is a literature survey of computational location privacy, meaning computation-based privacy mechanisms that treat location data as geometric information. This definition includes privacy-preserving algorithms like anonymity and obfuscation as well as privacy-breaking algorithms that exploit the geometric nature of the data. The survey omits non-computational techniques like manually inspecting geotagged photos, and it omits techniques like encryption or access control that treat location data as general symbols. The paper reviews studies of peoples' attitudes about location privacy, computational threats on leaked location data, and computational countermeasures for mitigating these threats.
Nonparametric density deconvolution by weighted kernel estimators
Authors: Martin L. Hazelton, Berwin A. Turlach
Venue: Statistics and Computing (2009)

Nonparametric density estimation in the presence of measurement error is considered. The usual kernel deconvolution estimator seeks to account for the contamination in the data by employing a modified kernel. In this paper a new approach based on a weighted kernel density estimator is proposed. Theoretical motivation is provided by the existence of a weight vector that perfectly counteracts the bias in density estimation without generating an excessive increase in variance. In practice a data driven method of weight selection is required. Our strategy is to minimize the discrepancy between a standard kernel estimate from the contaminated data on the one hand, and the convolution of the weighted deconvolution estimate with the measurement error density on the other hand. We consider a direct implementation of this approach, in which the weights are optimized subject to sum and non-negativity constraints, and a regularized version in which the objective function includes a ridge-type penalty. Numerical tests suggest that the weighted kernel estimation can lead to tangible improvements in performance over the usual kernel deconvolution estimator. Furthermore, weighted kernel estimates are free from the problem of negative estimation in the tails that can occur when using modified kernels. The weighted kernel approach generalizes to the case of multivariate deconvolution density estimation in a very straightforward manner.
Multicast capacity of wireless ad hoc networks
Authors: Xiang-Yang Li
Venue: IEEE/ACM Transactions on Networking (TON) (2009)

Assume that n wireless nodes are uniformly randomly deployed in a square region with side-length a and all nodes have the uniform transmission range r and uniform interference range R > r. We further assume that each wireless node can transmit (or receive) at W bits/second over a common wireless channel. For each node vi, we randomly and independently pick k-1 points pi,j (1 ≤ j ≤ k-1) from the square, and then multicast data to the nearest node for each pi,j. We derive matching asymptotic upper bounds and lower bounds on multicast capacity of random wireless networks. Under protocol interference model, when a2/r2 = O(n/log(n)), we show that the total multicast capacity is Θ (√n/log n ċ (W/√k)) when k = O(n/log n); the total multicast capacity is Θ (W) when k = Ω(n/log n). We also study the capacity of group-multicast for wireless networks where for each source node, we randomly select k - 1 groups of nodes as receivers and the nodes in each group are within a constant hops from the group leader. The same asymptotic upper bounds and lower bounds still hold. We also extend our capacity bounds to d-dimensional networks.
High-k dielectrics for future generation memory devices (Invited Paper)
Authors: J. A. Kittl, K. Opsomer, M. Popovici, N. Menou, B. Kaczer, X. P. Wang, C. Adelmann, M. A. Pawlak, K. Tomida, A. Rothschild, B. Govoreanu, R. Degraeve, M. Schaekers, M. Zahid, A. Delabie, J. Meersschaut, W. Polspoel, S. Clima, G. Pourtois, W. Knaepen, C. Detavernier, V. V. Afanas'ev, T. Blomberg, D. Pierreux, J. Swerts, P. Fischer, J. W. Maes, D. Manger, W. Vandervorst, T. Conard, A. Franquet, P. Favia, H. Bender, B. Brijs, S. Van Elshocht, M. Jurczak, J. Van Houdt, D. J. Wouters
Venue: Microelectronic Engineering (2009)

The requirements and development of high-k dielectric films for application in storage cells of future generation flash and Dynamic Random Access Memory (DRAM) devices are reviewed. Dielectrics with k-value in the 9-30 range are studied as insulators between charge storage layers and control gates in flash devices. For this application, large band gaps (>6eV) and band offsets are required, as well as low trap densities. Materials studied include aluminates and scandates. For DRAM metal-insulator-metal (MIM) capacitors, aggressive scaling of the equivalent oxide thickness (with targets down to 0.3nm) drives the research towards dielectrics with k-values >50. Due to the high aspect ratio of MIMCap structures, highly conformal deposition techniques are needed, triggering a substantial effort to develop Atomic Layer Deposition (ALD) processes for the deposition of metal gates and high-k dielectrics. Materials studied include Sr- and Ba-based perovskites, with SrTiO"3 as one of the most promising candidates, as well as tantalates, titanates and niobates.
Support for Urgent Computing Based on Resource Virtualization
Authors: Andrés Cencerrado, Miquel Ángel Senar, Ana Cortés
Venue: Proceedings of the 9th International Conference on Computational Science: Part I (2009)

Virtualization technologies provide flexible execution environments that could bring important benefits for computational problems with strong deadlines. Large Grid infrastructures are becoming available nowadays and they could be a suitable environment to run such on-demand computations that might be used in decision-making processes. For these computation, we encounter the need to deliver as much resources as possible at particular times. These resources may be provided by different institutions belonging to a grid infrastructure but there are two important issues that must be satisfied. Firstly, all resources must be correctly configured and all the components needed by the application must be properly installed. If there is something small missing that is required then applications will fail. Secondly, the execution of urgent applications must be made quickly in order to produce useful results in time. If applications must wait in a queue, results might be useless because they are obtained too late. To address these issues, we describe a job management service, based on virtualization techniques, that avoids configuration problems and increases the number of available resources to run applications with critical deadlines. We describe the main components of our service that can be used on top of common batch queue systems and we show some experimental results that prove the benefits of applying time-sharing techniques on the virtual machines to increase the performance of urgent computations. 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
Probability model for costs
Authors: Daniela Damian
Venue: Proceedings of the 10th WSEAS international conference on Mathematical methods, computational techniques and intelligent systems (2008)

This article presents a probabilistic model for the costs of production weighed with quantitative units. With help of this model we can calculate an average value of the costs. Because the model is based on real production process, its elements and characteristics are defined in their contents.
An extension of interior point potential reduction algorithm to solve general LCPs
Authors: Laura Giacomo
Venue: Journal of Global Optimization (2009)

Linear complementarity problems (LCP) may be solved if their condition number, defined appropriately is positive. This paper presents a transformation for the LCP which satisfy mild conditions to a form which will have a positive condition number. For these extensive classes an Interior point method can be used to solve it.
UWE-R: an extension to a web engineering methodology for rich internet applications
Authors: Leonardo Machado, Orlando Filho, João Ribeiro
Venue: WSEAS Transactions on Information Science and Applications (2009)

This paper introduces UWE-R, an extension to an existing Web Engineering Methodology (UML For Web Engineering - UWE) to model Rich Internet Applications (RIA). Initially it presents the basic concepts behind RIA and UWE, showing the reasons for choosing this methodology among many others. After presenting the proposed extensions for UWER, a modeling instance is shown using a real web site with RIA features. This work concludes with future directions and issues to be addressed.
Composition and Independence of High-Level Net Processes
Authors: H. Ehrig, K. Hoffmann, K. Gabriel, J. Padberg
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2009)

Mobile ad-hoc networks (manets) are networks of mobile devices that communicate with each other via wireless links without relying on an underlying infrastructure. To model workflows in manets adequately a formal technique is given by algebraic higher-order nets. For this modeling technique we here present a high-level net process semantics and results concerning composition and independence. Based on the notion of processes for low-level Petri nets we analyse in this paper high-level net processes defining the non-sequential behaviour of high-level nets. In contrast to taking low-level processes of the well known flattening construction for high-level nets our concept of high-level net processes preserves the high-level structure. The main results are the composition, equivalence and independence of high-level net processes under suitable conditions. Independence means that they can be composed in any order leading to equivalent high-level net processes which especially have the same input/output behaviour. All concepts and results are explained with a running example of a mobile ad-hoc network in the area of a university campus.