By Topic

Systems and Computer Science (ICSCS), 2012 1st International Conference on

Date 29-31 Aug. 2012

Filter Results

Displaying Results 1 - 25 of 29
  • Non-asymptotic fractional order differentiators via an algebraic parametric method

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (426 KB) |  | HTML iconHTML  

    Recently, Mboup, Join and Fliess [27], [28] introduced non-asymptotic integer order differentiators by using an algebraic parametric estimation method [7], [8]. In this paper, in order to obtain non-asymptotic fractional order differentiators we apply this algebraic parametric method to truncated expansions of fractional Taylor series based on the Jumarie's modified Riemann-Liouville derivative [14]. Exact and simple formulae for these differentiators are given where a sliding integration window of a noisy signal involving Jacobi polynomials is used without complex mathematical deduction. The efficiency and the stability with respect to corrupting noises of the proposed fractional order differentiators are shown in numerical simulations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Impact of overlay properties upon a P2P approach for parallel B&B

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB) |  | HTML iconHTML  

    The state-of-the-art large scale approach for solving NP-hard permutation-like problems using parallel Branch-and-Bound (B&B) techniques is based on a Master-Slave model which is known to be limited in terms of scalability. To overcome this limitation, we designed a Peer-to-Peer (P2P) approach that can handle a huge amount of computational resources in a fully distributed way, that is without the need of any centralized coordinator. The operation of such a decentralized parallel algorithm relies mainly upon the communications between the computational entities. Thus, the network overlay shall have an impact on the performances of the approach. In this paper, we study this impact through selecting some state-of-the-art topologies and through experimenting our protocol using these topologies. Results show that (1) our approach has a globally improved scalability, (2) it performs at best with topologies offering a good trade-off between the diameter and the average degree of the nodes, (3) our approach performs well using topologies presenting simple structures like N-ary trees and random graphs, which is a good indication for evolving towards dynamic environments, where computational entities can join or leave the network at any time. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improving classifier agents with order books information

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (211 KB) |  | HTML iconHTML  

    In the study of financial phenomena, agent-based artificial markets are efficient tools for testing economic assumptions of market regulation. While it is easy to populate these virtual worlds with “basic” chartists agents using price history (increase or decrease of prices, moving averages, ...), it is nevertheless necessary, in order to study rationality phenomena and influence between agents, to add some kind of learning agents. Several authors have of course already been interested in adaptive techniques but they mainly take into account price history. But prices are only consequences of orders and therefore reasoning about orders provides a step advance in the deductive process. In this paper we show how to take into account the whole information about the market, including how to leverage information from the order books such as the best limits, size of bid-ask spread or waiting liquidities to accommodate more effectively to market offerings. Like B. Arthur we focus here on the use of LCS agents. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time sensor data for efficient localisation employing a weightless neural system

    Publication Year: 2012 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (234 KB) |  | HTML iconHTML  

    Mobile robotic localisation obtained from simple sensor data potentially offers real-time real-world integration. Computationally highly efficient Weightless Neural Networks, when used for location determination, further enhances performance potential. This paper introduces techniques for the identification of rooms or locations in the absence of complex and succinct information. Using simple floor colour and texture, and room geometrics from ranging data, although inherent uncertainties exist, these limited simple fused real-time sensor data can be easily resolved into a room identification criterion using architectures generated by a Genetic Algorithm technique applied to a Weightless Neural Network Architecture. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Defining a measure of cloud computing elasticity

    Publication Year: 2012 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB) |  | HTML iconHTML  

    Cloud computing has gathered great attention recently as a method for eliminating or at least reducing expensive setup and maintenance cost of computing resources. Cloud computing has many key characteristics such as reliability, multi-tenancy and rapid elasticity. However, these characteristics suffer from the lack of clear and quantitative measures. In this paper, we provide a preliminary work that can help in providing a set of benchmarks for a cloud computing performance. More specifically, we provide an approach for measuring the elasticity of a cloud. Elasticity of a cloud computing system refers to its ability to expand and contract overtime in response to users' demands. The work presented in this paper is inspired by the definition of elasticity that is used in physics. This definition is adopted to represent the basic features of a cloud computing environment and its parameters that are related to elasticity. Case study shows the adoption methodology and highlights some of the basic parameters affecting elasticity as measured by the proposed approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Preliminary remarks on option pricing and dynamic hedging

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (406 KB) |  | HTML iconHTML  

    An elementary arbitrage principle and the existence of trends in financial time series, which is based on a theorem published in 1995 by P. Cartier and Y. Perrin, lead to a new understanding of option pricing and dynamic hedging. Intricate problems related to violent behaviors of the underlying, like the existence of jumps, become then quite straightforward by incorporating them into the trends. Several convincing computer experiments are reported. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A recursive Bayesian filter for landmark-based localisation of a wheelchair robot

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (620 KB) |  | HTML iconHTML  

    An odometry model, represented by a set of nodes (waypoints), is considered to be the infrastructure of any probabilistic-based localisation method. Gaussian and nonparametric filters utilise an odometry model to localise robots, while predictions are made by the filters to actively correct the robot's location and coordination. In this work, we present a recursive Bayesian filter for landmark recognition, which is used to verify the pose of a robotic wheelchair at a certain node location. The Bayesian rule in the proposed method does not incorporate a control action to rectify the robot's pose (passive localisation). The filter approximates the robot's pose based on a feature extraction sensor model. Features are extracted from local environmental regions (landmarks), and each landmark is assigned with a distinct posterior probability (signature), at each node location. A node is verified by the robot when the covariance between the posterior and prior probability falls bellow a threshold. We tested the proposed method in an indoor environment where accurate localisation results have been obtained. The experimentation demonstrated the robustness of the filter to work for passive localisation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cryptographic methods for securing the YML framework

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB) |  | HTML iconHTML  

    YML framework is a well-adapted advanced tool to support designing and executing portable parallel applications over large scale peer to peer and grid middlewares. We believe that it is necessary to consider the crucial security concerns for the improvement and extension of the framework. In this paper, two security mechanisms were introduced for the first time. To ensure the computing resources being utilized properly and legitimately, a lightweight authentication protocol was proposed, enabling the user to log in YML with 2 XOR and 1 HASH operation, meanwhile, a splitting way was adopted to distribute the secret key, making only the application requester can obtain the result. To safeguard the process of data exchanging, an efficient threshold encryption scheme was proposed. By generating a set of matched pieces of key, the data can be transformed into efficiently-recoverable half-ciphertext, which is able to transfer in public channel securely. Furthermore, dynamical addition of peers is supported in the scheme. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fault diagnosis on a magnetically supported plate

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB) |  | HTML iconHTML  

    A model-based online fault-diagnosis scheme for an electromagnetically supported plate is presented as an example of a nonlinear and open-loop unstable system. First, residuals for sensor as well as for actuator faults are generated using algebraic derivative estimators. Then, the robust detection and isolation of step-like sensor and actuator faults is presented. The performance of the proposed algorithms is illustrated by experimental results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Derivative-free Kalman Filtering for autonomous navigation of unmanned ground vehicles

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (294 KB) |  | HTML iconHTML  

    The paper proposes derivative-free nonlinear Kalman Filtering and state estimation-based control for MIMO nonlinear dynamical systems, such as unmanned ground vehicles. The considered nonlinear filtering scheme which is based on differential flatness theory can be applied to the autonomous vehicle model without the need for calculation of Jacobian matrices, and in general extends the class of MIMO nonlinear systems for which derivative-free Kalman Filtering can be performed. Nonlinear systems such as unmanned ground vehicles, satisfying the differential flatness property, can be written in the Brunovsky (canonical) form via a transformation of their state variables and control inputs. After transforming the nonlinear system to the canonical form it is straightforward to apply the standard Kalman Filter recursion. The performance of the proposed derivative-free nonlinear filtering scheme is tested through simulation experiments on the problem of state estimation-based control for autonomous navigation of unmanned ground vehicles. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Path planning with PH G2 splines in ℝ2

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (364 KB) |  | HTML iconHTML  

    In this article, we justify the use of parametric planar Pythagorean Hodograph spline curves in path planning. The elegant properties of such splines enable us to design an efficient interpolator algorithm, more precise than the classical Taylor interpolators and faster than an interpolator based on arc length computations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improving the dynamic accuracy of elastic industrial robot joint by algebraic identification approach

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1160 KB) |  | HTML iconHTML  

    In this paper, an improvement of the dynamic accuracy of a flexible robot joint is addressed. Based on the observation of the measured axis deformation, a simplified elastic joint model is deduced. In the first step, the non-linear model component's is analyzed and identified in the cases of the gravity bias and the friction term. In the second step, a non-asymptotically algebraic fast identification of the oscillatory behavior of the robot axis is introduced. Finally, the performances of the identification approach are exploited in order to improve the dynamic accuracy of a flexible robot axis. This is done experimentally by the combination of the adaptation of the jerk time profile to reduce the end-point vibration and the model-based pre-compensation of the end-point tracking error. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Smart monitoring and controlling of wind turbines farms based on wireless sensors networks

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (812 KB) |  | HTML iconHTML  

    The importance of alternative energy sources increases year by year, implying that the monitoring and controlling design of alternative energy generators become more significant. Wind power has a great potential to supply renewable energy without dependence on traditional fossil oil technologies. The monitoring of wind turbines can facilitate the prevention of accidental downtime due to component or structure failure. The acquisition of data under different conditions can be time and cost consuming. Low-cost, low power wireless sensors have materialized as a window for these applications. Economical and flexible wireless sensors networks can be installed within a large structure to evaluate the response and performing monitoring algorithms. In this paper, wireless sensors are deployed into a wind turbine farm to monitor the structures to present models of wind turbine behavior and response to loading and controlling the generator parameters by getting even to rewrite the control algorithm from the system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On real-time feedback control systems: Requirements, achievements and perspectives

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB) |  | HTML iconHTML  

    The present article is a position paper reviewing the main requirements and existing achievements of co-design approaches for real-time control and computing. This problem arises with the increasing complexity of modern computers which require more integrated methodologies, specifically suited to critical embedded systems. The general problem to be solved is the achievement of multi-objective goals (i.e. mixing stability, performance and dependability requirements) under constraints of limited execution resources (combining hardware and software components in CPUs and networks). It is expected that co-design approaches, handling the constraints arising from the control and real-time computing domains at early design time, can improve the overall effectiveness of distributed real-time controllers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • WACA: Workload and cache aware load balancing policy for web services

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (425 KB) |  | HTML iconHTML  

    The popularity of the web applications has shown rapid growth on Web Services and Cloud Computing. One of the major challenge in Web applications is that it need to process massive files and data-sets to respond to an increasing number of users requests. These data may range from multimedia data to sensor data. Along with the size of data, user satisfaction is an important constraint imposing Quality of Service requirements. Therefore the use of web clusters becomes necessary for numerous applications, fostering the need of efficient load distribution strategy. This article presents a new load balancing policy called Workload And Cache Aware load balancing (WACA) policy aimed at reducing the information retrieval time of the processor using Bloom Filter Based cache summaries. The WACA is a centralized load balancing algorithm which routes the incoming requests to the machine where the underlying data will most probably be in its cache without overloading any nodes in the cluster. The proposed policy was developed and tested on a load balancing framework called CLOUDIZER, and the performance of the strategy was compared over the traditional algorithms. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Discrete-time LQG control with disturbance rejection for variable speed wind turbines

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    In this paper a discrete-time LQG controller is proposed for horizontal wind turbines, which makes possible to eliminate the disturbance influence on the system output. The control objective consists of maintaining the output power constant despite the wind variation, reducing, in the meantime, the fatigue that leads to damage of the turbine components. The discrete LQG controller has the advantage that can be easily implemented on a physical controller in order to be used on a real wind turbine. The wind turbine behavior is described by a nonlinear model based on the general equation of motion in a mechanical system and other equations specific to the system. The model is then linearized around a particular operating point in order to obtain a wind turbine system representation suitable for controller design. The performances of the system controlled with a discreet LQG controller are illustrated and analyzed using a simulation environment. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Algebraic approach for R-peak detection in the ElectroCardioGram (ECG) signal

    Publication Year: 2012 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (347 KB) |  | HTML iconHTML  

    In this paper, we present a novel method for R-peak detection in the ElectroCardioGram (ECG) signal in a noisy environment. We interpret the R-peak occurrence as an irregularity in the signal. Thereby, we transform the problem of R-peaks detection into irregularity instants estimation. To point out these irregularities, we use an algebraic approach based on differential algebra and operational calculus. To make the R-peak detection more accuracy, we propose a new decision rule permitting a reliable distinction between R-peaks and false alarms. To assess the validity of theoretical analysis, numerical simulations, according to signals from the MIT-BIH arrhythmias database, are performed. To carry out the performance of the proposed method, a comparison with the most used technique in literature is achieved. The obtained results show the robustness of the algebraic method in the context of complicated pathologies as well as to various types of noises. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Mathematical properties of a semi-classical signal analysis method: Noisy signal case

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (313 KB) |  | HTML iconHTML  

    Recently, a new signal analysis method based on a semi-classical approach has been proposed [1]. The main idea in this method is to interpret a signal as a potential of a Schrodinger operator and then to use the discrete spectrum of this operator to analyze the signal. In this paper, we are interested in a mathematical analysis of this method in discrete case considering noisy signals. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Online frequency band estimation and change-point detection

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2150 KB) |  | HTML iconHTML  

    Detecting change-points in time series is at the heart of numerous applications, as abrupt changes in signal properties are quite common in natural and industrial processes. In this paper we propose an algorithm for a particular change-point detection problem where the frequency band of the signal changes at some points in the time axis. Apart from detecting the change-points, the proposed algorithm is also able to estimate the frequency bands. The main idea of the algorithm is to consider a simple local bandlimited model to represent the input signal in each sliding time window. The local model consists of a sum of two exponentials that, in the frequency domain, reads as the transfer function of a second order bandpass filter. Relying on the operational calculus, we obtain an explicit estimation of the parameters, that indicate the cut-off frequencies associated to each time window. The implementation is done in discrete time domain where the cut-off frequencies are computed as a combination of outputs of several FIR filters, providing a low computational cost online estimation. Experimental results show the efficiency and the stability of this algorithm even in presence of a moderate amount of noise. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stability, l1-gain analysis and control synthesis for delayed discrete-time positive switched systems

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    This paper presents the exponential stability, l1-gain analysis and control synthesis problems for discrete-time positive switched linear systems with time-varying delays. By using the methods of average dwell time, sufficient stability conditions are proposed and expressed as linear matrix inequalities (LMIs). Based on the obtained results, an effective method which is used for the construction of stabilizing feedback controller is derived, and a numerical example is provided to show the potential of the developed results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An improved approach to video target tracking based on Mean Shift

    Publication Year: 2012 , Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1105 KB) |  | HTML iconHTML  

    This paper proposes an algorithm based on Mean Shift, which improves on the kernel function, alterative weights, combing with Kalman filter and neighborhood searching. These improvements not only enhance the capacity of target tracking, but also reduce the computations to satisfy the need of the real-time job. Furthermore, experimental results illuminate that the proposed algorithm can cope with clutter, target partial occlusions, scale variations and fast moving in the real-time video target tracking. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improving the effective resolution of optical remote sensor with adapted reciprocal cell

    Publication Year: 2012 , Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (556 KB) |  | HTML iconHTML  

    Remote sensing image is degraded by a variety of factors. Sub-pixel imaging technology is a state-of-the-art method to reduce the camera size and improve the spatial resolution. In this paper, we introduce several sub-pixel imaging systems and discuss the resolution of different sampling systems. Then we use adapted reciprocal cell to correct the vicarious spectrum and improve the effectively resolution. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Variable sampled delayed feedback observer design for networked visual servoing systems

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB) |  | HTML iconHTML  

    The present paper deals with a new continuous undelayed state observer design approach by using only the sampled and delayed measurements where the sampling period and delayed value are variable and unknown. This proposed piecewise continuous observer, which is derived by using the theory of a particular hybrid systems called Piecewise Continuous Systems, has a very simple structure and can be easily implemented to the networked visual servoing systems. The observer stability is also analyzed and demonstrated. To show the proposed observer performance, a comparison with a Lyapunov-Krasovskii technique and descriptor representation based observer is conducted via a numerical example. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Observer design for discrete-time switched positive systems with time-varying delays

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (274 KB) |  | HTML iconHTML  

    This paper investigates the design problem of exponential positive observer for a class of discrete-time switched positive linear systems with time-varying delay. A sufficient exponential stability criterion is proposed in terms of linear matrix inequalities (LMIs) for the underlying system under average dwell time switching. Then, based on the stability results, sufficient conditions for the existence of exponential positive observers are established. A numerical example is given to show the effectiveness of the proposed results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Short investigation on system diagnosis regarding parameter estimation

    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (201 KB) |  | HTML iconHTML  

    Fault Detection and Diagnosis (FDD) is a research field that has known a rapid development due to the increasing safety and dependability requirements in high-risk applications. Consequently, a significant number of FDD techniques and associated algorithms were developed, and their effectiveness was proven in practice. However, given the current trend that consist of designing and developing integrated real-time risk-management systems for safety-critical installations, it became obvious that most of these techniques, in their original form, fail to provide an efficient solution to the problems related to the implementation of the corresponding FDD schemes in real-time; this paper focuses on the use of parameter estimation techniques for achieving these objectives. First, a global overview of the current state of the FDD research is given, then the most commonly used parameter estimation techniques are described, with an emphasis on the possibility of using them within FDD schemes that respond to the requirements of modern industrial applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.