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Lost-in-Space Star Identification Using Planar Triangle Principal Component Analysis Algorithm

MATHEMATICAL PROBLEMS IN ENGINEERING 2015年第1期2015卷 1-11页

作者： Zhou, Fuqiang Ye, Tao Beihang Univ Minist Educ Key Lab Precis Optomechatron Technol Beijing 100191 Peoples R China

It is a challenging task for a star sensor to implement star identification and determine the attitude of a spacecraft in the lost-in-space mode. Several algorithms based on triangle method are proposed for star identification in this mode. However, these methods hold great time consumption and large guide star catalog memory size. The star identification performance of these methods requires improvements. To address these problems, a star identification algorithm using planar triangle principal component analysis is presented here. A star pattern is generated based on the planar triangle created by stars within the field of view of a star sensor and the projection of the triangle. Since a projection can determine an index for a unique triangle in the catalog, the adoption of the k-vector range search technique makes this algorithm very fast. In addition, a sharing star validation method is constructed to verify the identification results. Simulation results show that the proposed algorithm is more robust than the planar triangle and P-vector algorithms under the same conditions.

关键词： PRINCIPAL components analysis computer algorithms VECTOR analysis INFORMATION sharing PROBLEM solving

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Adaptive supervisory predictive control of a hybrid fed-batch reactor with slow actuator

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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 2007年第24期46卷 8050-8057页

作者： Skrjanc, Igor Univ Ljubljana Fac Elect Engn Lab Proc Automat & Informatisat Lab Modelling Simulat & Control Ljubljana 1000 Slovenia

In this paper, adaptive supervisory predictive functional control is discussed for applications in a fed-batch reactor with slow continuous mixing valve, which acts as an actuator. The optimal operation regime of the reactor is to follow the reference trajectory without significant overshoot and to minimize the overall batch time. By adding the ingredients during the batch procedure, the volume in the reactor varies, tending to increase with time, as does the heat-transfer surface inside the reactor. This change causes variations in the batch-reactor dynamics, which can produce serious problems with the reactor's core-temperature control. Another problem that arises is the disturbance in the temperature inside the reactor, when additional ingredients added are at the outside temperature. In the pharmaceutical industry, a huge number of fed-batch reactors similar to ours are used for the production of drugs. The quality control is extremely strict, and it is necessary to follow the exact production recipe. The adaptive algorithm based on recursive identification is used to deal with varying dynamics of the systems;the predictive functional control algorithm is used because of its simple implementation, which can be realized also in programmable logic controllers;and the supervisory control level is designed to cope with the physical constraints and the discrete on/off valves that are used as actuators. The possible use of the proposed adaptive control algorithm in a real application was studied by taking into account a very slow actuator.

关键词： Reactors batch reactor Predictive control predictive functional control heat transfer surface oversight computer algorithms actuators

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Quantifying the potential benefits of constrained control for a large-scale system

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IEE PROCEEDINGS-CONTROL THEORY AND APPLICATIONS 2002年第5期149卷 423-432页

作者： Ma, DL VanAntwerp, JG Hovd, M Braatz, RD Univ Illinois Urbana IL 61801 USA Calvin Coll Dept Engn Grand Rapids MI 49546 USA Norwegian Univ Sci & Technol Dept Engn Cybernet N-7030 Trondheim Norway

It is of practical interest to identify which processes will benefit significantly from the use of constrained control algorithms such as model predictive control, and which will not. Explicit conditions are derived that identify whether a particular process may benefit from constraint handling. These conditions are also useful for understanding the interactions between design and control for a particular system, especially for actuator placement and selection. The conditions are computable for a large-scale system directly from its transfer function model, a simulation model (e.g. defined by a set of ordinary/partial-differential equations and algebraic conditions), or experimental input-output data. The formulation considers the effects of measurement noise, process disturbances, model uncertainties, plant directionality and the quantity of experimental data. The conditions are illustrated by application to a paper-machine model constructed from industrial data.

关键词： model uncertainty Quantify INPUT-OUTPUT computer algorithms TRANSFER FUNCTIONS constraint handling large-scale systems

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Label-free comparative analysis of proteomics mixtures using chromatographic alignment of high-resolution μLC-MS data

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ANALYTICAL CHEMISTRY 2008年第4期80卷 961-971页

作者： Finney, Gregory L. Blackler, Adele R. Hoopmann, Michael R. Canterbury, Jesse D. Wu, Christine C. MacCoss, Michael J. Univ Washington Dept Genome Sci Seattle WA 98195 USA Univ Colorado Hlth Sci Dept Pharmacol Aurora CO 80045 USA

Label-free relative quantitative proteornics is a powerful tool for the survey of protein level changes between two biological samples. We have developed and applied an algorithm using chromatographic alignment of mu LC-MS runs to improve the detection of differences between complex protein mixtures. We demonstrate the performance of our software by finding differences in E. coli protein abundance upon induction of the lac operon genes using isopropyl P-D-thiogalactopyranoside. The use of our alignment gave a 4-fold decrease in mean relative retention time error and a 6-fold increase in the number of statistically significant differences between samples. Using a conservative threshold, we have identified 5290 total mu LC-MS regions that have a different abundance between these samples. Of the detected difference regions, only 23% were mapped to MS/MS peptide identifications. We detected 74 proteins that had a greater relative abundance in the induced sample and 21 with a greater abundance in the uninduced sample. We have developed an effective tool for the label-free detection of differences between samples and demonstrate an increased sensitivity following chromatographic alignment.

关键词： PROTEOMICS MIXTURES PROTEINS PEPTIDES ESCHERICHIA coli CHROMATOGRAPHIC analysis GENOMES MASS spectrometry computer algorithms

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Application of IR-MAD using synthetically fused images for change detection in hyperspectral data

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REMOTE SENSING LETTERS 2015年第8期6卷 578-586页

作者： Wang, Biao Choi, Seok-Keun Han, You-Kyung Lee, Soung-Ki Choi, Jae-Wan Chungbuk Natl Univ Sch Civil Engn Cheongju 361763 Chungbuk South Korea Fdn Bruno Kessler Ctr Informat & Commun Technol Trento Italy

The main objective of this letter is to improve the accuracy of unsupervised change detection method and minimize registration errors among multi-temporal images in the change detection process. To this end, iteratively regularized multivariate alteration detection (IR-MAD) is applied to synthetically fused images. First, four synthetically fused hyperspectral images are generated using the block-based fusion method. Then, the IR-MAD is applied to three pairs of the fused images using integrated IR-MAD variates, to decrease the falsely detected changes. To focus on the mis-registration effects, we apply the method to both a correctly registered data-set and a data-set with deliberately misaligned images. In this experiment using multi-temporal Hyperion images, the changed areas are more efficiently detected by our method than by the original IR-MAD algorithm.

关键词： REMOTE sensing RESEARCH HYPERSPECTRAL imaging systems computer algorithms IMAGE registration DIGITAL image processing

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Learning Bayesian networks for discrete data

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COMPUTATIONAL STATISTICS & DATA ANALYSIS 2009年第4期53卷 865-876页

作者： Liang, Faming Zhang, Jian Texas A&M Univ Dept Stat College Stn TX 77843 USA Univ York Dept Math York YO10 5DD N Yorkshire England

Bayesian networks have received much attention in the recent literature. In this article, we propose an approach to learn Bayesian networks using the stochastic approximation Monte Carlo (SAMC) algorithm. Our approach has two nice features. Firstly, it possesses the self-adjusting mechanism and thus avoids essentially the local-trap problem suffered by conventional MCMC simulation-based approaches in learning Bayesian networks. Secondly, it falls into the class of dynamic importance sampling algorithms;the network features can be inferred by dynamically weighted averaging the samples generated in the learning process, and the resulting estimates can have much lower variation than the single model-based estimates. The numerical results indicate that our approach can mix much faster over the space of Bayesian networks than the conventional MCMC simulation-based approaches. (C) 2008 Elsevier B.V. All rights reserved.

关键词： GRAPHICAL modeling (Statistics) BAYESIAN analysis computer algorithms STOCHASTIC approximation MONTE Carlo method MATHEMATICAL literature ESTIMATION theory

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Channel Rectification and Signal Estimation Based on EIV Model in Massive MIMO System

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MATHEMATICAL PROBLEMS IN ENGINEERING 2017年第1期2017卷 1-7页

作者： Zhong, Liang Huang, Li Kong, Zhengmin China Univ Geosci Sch Mech Engn & Elect Informat Wuhan 430072 Peoples R China South Cent Univ Nationalities Coll Elect & Informat Hubei Key Lab Intelligent Wireless Commun Wuhan 430074 Peoples R China Wuhan Univ Dept Automat Wuhan 430072 Peoples R China

The performance of Massive MIMO is severely limited by channel estimation error, which is caused by pilot contamination and channel aging. In this paper, we propose an estimation algorithm based on the weighted total least-squares method with errors-invariables (EIV) model to alleviate the influence of pilot contamination and channel aging. Then, a channel rectification method has been investigated to diminish the inaccuracy of channel estimation. Comparing with the traditional methods, it not only helps to make the signal estimation more accurate, but also provides opportunities to correct the channel model with estimation error and update the aged channel statement information. Simulations are provided to verify the efficacy of this method.

关键词： MIMO systems ERRORS-in-variables models CHANNEL estimation computer simulation INFORMATION processing computer algorithms

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Hierarchical tone mapping based on image colour appearance model

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IET computer VISION 2014年第4期8卷 358-364页

作者： Xiao, Jinsheng Li, Wenhao Liu, Guoxiong Shaw, Shih-Lung Zhang, Yongqin Wuhan Univ Sch Elect Informat Wuhan 430072 Peoples R China Wuhan Univ State Key Lab Informat Engn Surveying Mapping & R Wuhan 430079 Peoples R China Univ Tennessee Dept Geog Knoxville TN 37996 USA Peking Univ Inst Comp Sci & Technol Beijing 100871 Peoples R China

To solve the problem of low efficiency and poor effect of the current tone mapping methods for the high dynamic range images, the authors propose a hierarchical tone mapping algorithm based on colour appearance model. The discrete Gaussian kernel is used to speed up the bilateral filter. The operation of tone compression in RGB colour space is adopted to correct the colour casts. The extreme values of the pixels are also adjusted in the detail layer. Moreover, after the tone mapping, the colour saturation is enhanced in the image regions of rich details and sharp edges. Experimental results show that the proposed algorithm with less computational cost reduces the halo effect significantly, and achieves the natural colour and the rich details. It outperforms the state-of-the-art methods in terms of visual quality and objective indicators.

关键词： GAUSSIAN processes IMAGE processing PIXELS IMAGE compression computer algorithms KERNEL (Mathematics)

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Image-based rendering of range data with estimated depth uncertainty

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IEEE computer GRAPHICS AND APPLICATIONS 2004年第4期24卷 34-42页

作者： Hofsetz, C Ng, K Chen, G McGuinness, P Max, N Liu, Y Univ Vale Rio dos Sinos UNISINOS BR-93022000 Sao Leopoldo RS Brazil STMicroelect San Diego Lab San Diego CA USA Univ Calif Davis Davis CA 95616 USA

Image-based rendering (IBR) involves constructing an image from a new viewpoint, using several input images from different viewpoints. A rendering framework must be flexible enough to handle this kind of data. It must also be able to handle data extracted from several input images using far less accurate techniques--for example, stereo matching, which introduces a high level of uncertainty. The authors' attempt to define this uncertainty and use it in their rendering framework. When synthesizing new images from real input images, IBR techniques often neglect to take advantage of all the knowledge gathered from computer vision techniques during depth recovery. The authors' image-rendering approach involves three steps: depth extraction, uncertainty estimation, and rendering. Uncertainty is a vague term, which can refer to various aspects of the input images. For example, it can relate to the intrinsic or extrinsic camera parameters. Their technique of rendering depth with uncertainty using ellipsoidal Gaussian kernels is straightforward. They represent each depth uncertainty as an ellipsoid. INSET: Perspective Projection Approximation..

关键词： computer graphics computer vision PATTERN recognition systems IMAGE processing ARTIFICIAL intelligence computer algorithms

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Deterministic broadcast and gossiping algorithms for ad hoc networks

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JOURNAL OF SUPERCOMPUTING 2006年第2期37卷 115-144页

作者： Sinha, Koushik Srimani, Pradip K. Clemson Univ Dept Comp Sci Clemson SC 29634 USA

We present in this paper three deterministic broadcast and a gossiping algorithm suitable for ad hoc networks where topology changes range from infrequent to very frequent. The proposed algorithms are designed to work in networks where the mobile nodes possessing collision detection capabilities. Our first broadcast algorithm accomplishes broadcast in O(nlog n) for networks where topology changes are infrequent. We also present an O(nlog n) worst case time broadcast algorithms that is resilient to mobility. For networks where topology changes are frequent, we present a third algorithm that accomplishes broadcast in O(triangle center dot n log n+n center dot vertical bar M vertical bar) in the worst case scenario, where vertical bar M vertical bar is the length of the message to be broadcasted and triangle the maximum node degree. We then extend one of our broadcast algorithms to develop an O(Dn log n + D-2) algorithm for gossiping in the same network model.

关键词： MOBILE communication systems BROADCASTING industry RADIO networks computer algorithms TELECOMMUNICATION systems computer networks TOPOLOGY ELECTRONIC systems TELECOMMUNICATION INFORMATION technology

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