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Electronics, Robotics and Automotive Mechanics Conference

作者： Gualdron, O. Torres, I. Departamento de Ingeniería Electrónica Universidad de Pamplona Km 1 via Bucaramanga Colombia

ISBN: (纸本)9780769529745

We introduce a new variable selection approach, which converges much faster to the optimal set of variables for a given application. The new procedure runs in two steps. First, a coarse and very fast variable selection procedure, is applied: A figure of merit is defined and computed for every variable, a threshold value set and only the variables whose figure of merit is higher than the threshold are retained for further selection. Then, a fine-tuning selection based either on deterministic or stochastic methods is conducted on the variable subset that resulted from the first step. The method is demonstrated using a database consisting of vapors of acetone, ammonia and o-xylene and their binary mixtures (120 variables/measurement). Vapors can be simultaneously identified and quantified with a 92.7% success rate and the time needed for variable selection is reduced at least by a factor of 4

关键词： deterministic algorithms gas sensors sensor fusion stochastic processes deterministic method fine-tuning selection gas sensing application stochastic method threshold value set vapor database variable selection variable subset Input variables deterministic algorithms deterministic approach Sensor fusion Markov chain Gas sensors remote sensing application Stochastic Processes

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On a Shubert Algorithm-Based Global Extremum Seeking Scheme

On a Shubert Algorithm-Based Global Extremum Seeking Scheme

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51st IEEE Annual Conference on Decision and Control (CDC)

作者： Nesic, D. Nguyen, T. Tan, Y. Manzie, C. Univ Melbourne Dept Elect & Elect Engn Melbourne Vic 3010 Australia Univ Exeter Dept Engn Exeter EX4 4QF Devon England Univ Melbourne Dept Mech Engn Melbourne Vic 3010 Australia

ISBN: (纸本)9781467320665

This paper adapts the so-called Shubert algorithm for Extremum Seeking Control (ESC) to seek the global extremum (in presence of local extrema) of general dynamic plants. Different from derivative based methods that are widely used in ESC, the Shubert algorithm is a good representative of sampling optimization methods. With knowledge of the Lipschitz constant of an unknown static mapping, this deterministic algorithm seeks the global extremum. By introducing "waiting time" the proposed Shubert algorithm-based global extremum seeking guarantees the semi-global practical convergence (in the initial states) to the global extremum if compact sets of inputs are considered. Several numerical examples demonstrate how proposed method may be successfully deployed.

关键词： deterministic algorithms optimal control optimisation sampling methods

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Methods for Large Scale Hydraulic Fracture Monitoring

Methods for Large Scale Hydraulic Fracture Monitoring

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5th IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP)

作者： Ely, Gregory Aeron, Shuchin Tufts Univ Dept ECE Medford MA 02155 USA

ISBN: (纸本)9781467331463;9781467331449

In this paper we propose computationally efficient and robust methods for estimating the moment tensor and location of microseismic event(s) for large search volumes. Our contribution is two-fold. First, we propose a novel joint-complexity measure, namely the sum of nuclear norms which while imposing sparsity on the number of fractures (locations) over a large spatial volume, also captures the rank-1 nature of the induced wavefield pattern. This wavefield pattern is modeled as the outer-product of the source signature with the amplitude pattern across the receivers from a seismic source. A rank-1 factorization of the estimated wavefield pattern at each location can therefore be used to estimate the seismic moment tensor using the knowledge of the array geometry. In contrast to existing work this approach allows us to drop any other assumption on the source signature. Second, we exploit the recently proposed first-order incremental projection algorithms for a fast and efficient implementation of the resulting optimization problem and develop a hybrid stochastic & deterministic algorithm which results in significant computational savings.

关键词： moment tensors Hydraulic Fracking Projection algorithms Earthquakes Tensor Receivers deterministic algorithms

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Implementation of Smart Phone Video Plethysmography and Dependence on Lighting Parameters 37

Implementation of Smart Phone Video Plethysmography and Depe...

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37th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society (EMBC)

作者： Fletcher, Richard Ribon Chamberlain, Daniel Paggi, Nicholas Deng, Xinyue MIT 77 Massachusetts Ave Cambridge MA 02139 USA

ISBN: (纸本)9781424492701

The remote measurement of heart rate (HR) and heart rate variability (HRV) via a digital camera (video plethysmography) has emerged as an area of great interest for biomedical and health applications. While a few implementations of video plethysmography have been demonstrated on smart phones under controlled lighting conditions, it has been challenging to create a general scalable solution due to the large variability in smart phone hardware performance, software architecture, and the variable response to lighting parameters. In this context, we present a self-contained smart phone implementation of video plethysmography for Android OS, which employs both stochastic and deterministic algorithms, and we use this to study the effect of lighting parameters (illuminance, color spectrum) on the accuracy of the remote HR measurement. Using two different phone models, we present the median HR error for five different video plethysmography algorithms under three different types of lighting (natural sunlight, compact fluorescent, and halogen incandescent) and variations in brightness. For most algorithms, we found the optimum light brightness to be in the range 1000-4000 lux and the optimum lighting types to be compact fluorescent and natural light. Moderate errors were found for most algorithms with some devices under conditions of low-brightness (<500 lux) and high-brightness (>4000 lux). Our analysis also identified camera frame rate jitter as a major source of variability and error across different phone models, but this can be largely corrected through non-linear resampling. Based on testing with six human subjects, our real-time Android implementation successfully predicted the measured HR with a median error of -0.31 bpm, and an inter-quartile range of 2.1bpm.

关键词： HR Smart Phone Video Plethysmography Dependence on Lighting Parameters Heart Rate Smartphone Plethysmography Lighting Videotapes deterministic algorithms Interquartile range brightness Colour spectrum

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Efficient Construction of Global Time in SoCs despite Arbitrary Faults

Efficient Construction of Global Time in SoCs despite Arbitr...

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16th Euromicro Conference on Digital System Design (DSD)

作者： Lenzen, Christoph Fuegger, Matthias Hofstaetter, Markus Schmid, Ulrich MIT 77 Massachusetts Ave Cambridge MA 02139 USA Vienna Univ Technol Vienna Austria

ISBN: (纸本)9780769550749

In this paper, we show how to build synchronized clocks of arbitrary size atop of existing small-sized clocks, despite arbitrary faults. Our solution is both self-stabilizing and Byzantine fault-tolerant, and needs merely single-bit channels. It involves a reduction to Byzantine fault-tolerant consensus, which allows different consensus algorithms to be plugged in for matching the actual clock sizes and resilience requirements best. We demonstrate the practicability of our approach by means of an FPGA implementation and its experimental evaluation. To also address the cases where deterministic algorithms hit fundamental limits, we provide a novel randomized self-stabilizing Byzantine consensus algorithm that works very well also in these settings, along with its correctness proof and stabilization time analysis.

关键词： clocks deterministic algorithms fault tolerance integrated circuit reliability system-on-chip

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Online Matching with Stochastic Rewards

Online Matching with Stochastic Rewards

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IEEE 53rd Annual Symposium on Foundations of Computer Science (FOCS)

作者： Mehta, Aranyak Panigrahi, Debmalya Google Res Mountain View CA 94043 USA Microsoft Res Redmond WA USA

ISBN: (纸本)9781467343831

The online matching problem has received significant attention in recent years because of its connections to allocation problems in Internet advertising, crowd-sourcing, etc. In these real-world applications, the typical goal is not to maximize the number of allocations;rather it is to maximize the number of "successful" allocations, where success of an allocation is governed by a stochastic process which follows the allocation. To address such applications, we propose and study the online matching problem with stochastic rewards (called the ONLINE STOCHASTIC MATCHING problem) in this paper. Our problem also has close connections to the existing literature on stochastic packing problems;in fact, our work initiates the study of online stochastic packing problems. We give a deterministic algorithm for the ONLINE STOCHASTIC MATCHING problem whose competitive ratio converges to (approximately) 0.567 for uniform and vanishing probabilities. We also give a randomized algorithm which outperforms the deterministic algorithm for higher probabilities. Finally, we complement our algorithms by giving an upper bound on the competitive ratio of any algorithm for this problem. This result shows that the best achievable competitive ratio for the ONLINE STOCHASTIC MATCHING problem is provably worse than that for the (non-stochastic) online matching problem.

关键词： deterministic algorithms Stochastic allocation randomized algorithms Markov chain Reward Connections

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deterministic and Stochastic Study for an Infected Computer Network Model Powered by a System of Antivirus Programs

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DISCRETE DYNAMICS IN NATURE AND SOCIETY 2017年第Pt.3期2017卷 1-13页

作者： El Ansari, Youness El Myr, Ali Omari, Lahcen Sidi Mohamed Ben Abdellah Univ Dept Math Fac Sci Lab Comp Sci Modeling & Syst BP 1796 Atlas Fez Morocco

We investigate the various conditions that control the extinction and stability of a nonlinear mathematical spread model with stochastic perturbations. This model describes the spread of viruses into an infected computer network which is powered by a system of antivirus software. The system is analyzed by using the stability theory of stochastic differential equations and the computer simulations. First, we study the global stability of the virus-free equilibrium state and the virus-epidemic equilibrium state. Furthermore, we use the Ito formula and some other theoretical theorems of stochastic differential equation to discuss the extinction and the stationary distribution of our system. The analysis gives a sufficient condition for the infection to be extinct (i.e., the number of viruses tends exponentially to zero). The ergodicity of the solution and the stationary distribution can be obtained if the basic reproduction number R-p is bigger than 1, and the intensities of stochastic fluctuations are small enough. Numerical simulations are carried out to illustrate the theoretical results.

关键词： deterministic chaos deterministic algorithms COMPUTER simulation ANTIVIRUS software STOCHASTIC analysis

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Fast deterministic single-exposure coherent diffractive imaging at sub-Ångström resolution

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Physical Review B 2013年第9期87卷 094115-094115页

作者： A. J. Morgan A. J. D’Alfonso P. Wang H. Sawada A. I. Kirkland L. J. Allen School of Physics University of Melbourne Parkville Victoria 3010 Australia National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering Nanjing University Nanjing 210093 People's Republic of China Department of Materials University of Oxford Parks Road Oxford OX1 3PH United Kingdom JEOL Ltd 1-2 Musashino 3-Chome Akishima Tokyo 196 Japan

In coherent diffractive imaging (CDI), conventional image-forming optics are replaced by the solution of an inverse scattering problem which obtains the exit surface wave from the diffraction pattern. To date CDI implementations typically use nonlinear iterative solutions, often using more than one diffraction pattern, and have been mainly implemented in the optical and x-ray regimes. Here we present single-exposure CDI reconstructions of a region of a cerium dioxide nanocrystal, illuminated by a coherent electron probe, in which the positions of both cerium and the lighter oxygen atoms are recovered simultaneously. We employ a fast deterministic algorithm based on the iterative solution of a set of linear equations with input data obtained from the inverse Fourier transform of the diffraction pattern. The solution of the linear equations proceeds using a conjugate gradient least-squares method based on fast Fourier transforms. This allows regularization of the inversion problem by iteration number, making it robust to experimental noise. This approach is successful where standard nonlinear phase retrieval techniques for the same data set are not.

关键词： deterministic algorithms INVERSE scattering transform IMAGE reconstruction CERIUM OPTICAL properties of nanocrystals OXYGEN atom transfer reactions

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Efficient algorithms for the Data Exchange Problem under Fairness Constraints

Efficient Algorithms for the Data Exchange Problem under Fai...

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50th Annual Allerton Conference on Communication, Control, and Computing (Allerton)

作者： Milosavljevic, Nebojsa Pawar, Sameer Gastpar, Michael Ramchandran, Kannan Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA

ISBN: (纸本)9781467345392;9781467345378

In this paper we study the data exchange problem where a set of users is interested in gaining access to a common file, but where each has only partial knowledge about it as side-information. Given that the collective information of all the users is sufficient to allow recovery of the entire file, the goal is to minimize the sum of convex functions over the number of bits each user has to transmit in order to achieve the goal. A special case of this objective is the uniform cost, which essentially leads to a "fair" communication load distribution among the users. We consider the following side-information settings: (i) side-information in the form of uncoded packets of the file, where the users' side-information consists of subsets of the file packets;and (ii) side-information in the form of linearly correlated packets, where the users have access to linear combinations of the file packets. We provide a polynomial-time deterministic algorithm that finds an optimal communication scheme w.r.t. the transmission cost. To further lower the complexity, we also give a simple randomized algorithm inspired by our deterministic algorithm.

关键词： communication complexity data communication deterministic algorithms linear codes minimisation packet radio networks randomised algorithms

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Recursive Probability Trees for Bayesian Networks

Recursive Probability Trees for Bayesian Networks

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13th Conference of the Spanish-Association-for-Artificial-Intelligence (CAEPIA 2009)

作者： Cano, Andres Gomez-Olmedo, Manuel Moral, Serafin Perez-Ariza, Cora B. Univ Granada Dept Comp Sci & Artificial Intelligence E-18071 Granada Spain

ISBN: (纸本)9783642142635

This paper proposes a new data structure for representing potentials. Recursive probability trees are a generalization of probability trees. Both structures are able to represent context-specific independencies, but the new one is also able to hold a potential in a factorized way. This new structure can represent some kinds of potentials in a more efficient way than probability trees, and it can be the case that only recursive trees are able to represent certain factorizations. Basic operations for inference in Bayesian networks can be directly performed upon recursive probability trees.

关键词： Bayesian networks inference approximate computation deterministic algorithms probability trees

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