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A distributed origin-destination demand estimation approach for real-time traffic network management

TRANSPORTATION PLANNING AND TECHNOLOGY 2011年第3期34卷 217-230页

作者： Etemadnia, Hamideh Abdelghany, Khaled So Methodist Univ Dept Civil & Environm Engn Dallas TX 75275 USA

This paper describes a distributed recursive heuristic approach for the origin-destination demand estimation problem for real-time traffic network management applications. The distributed nature of the heuristic enables its parallelization and hence reduces significantly its processing time. Furthermore, the heuristic reduces dependency on historical data that are typically used to map the observed link flows to their corresponding origin-destination pairs. In addition, the heuristic allows the incorporation of any available partial information on the demand distribution in the study area to improve the overall estimation accuracy. The heuristic is implemented following a hierarchal multi-threading mechanism. Dividing the study area into a set of subareas, the demand of every two adjacent subareas is merged in a separate thread. The merging operations continue until the demand for the entire study area is estimated. Experiments are conducted to examine the performance of the heuristic using hypothetical and real networks. The obtained results illustrate that the heuristic can achieve reasonable demand estimation accuracy while maintaining superiority in terms of processing time.

关键词： demand estimation recursive algorithms real-time traffic management

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Numerical study of evaluating the optical quality of supersonic flow fields

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APPLIED OPTICS 2007年第23期46卷 5545-5551页

作者： Tao Wang Yan Zhao Dong Xu Qiuying Yang BeiHang Univ Sch Instrument ci & Optoelect Engn Dept Inertia Technol & Navigat Guidance Instrumen Beijing 100083 Peoples R China

A numerical method based on the uniform and hexahedral grids generated from computational fluid dynamics is presented for the analysis of aero-optical performance. A single grid is taken as a cell with isotropy and homogeneity inside, and it is assumed that the light rays transmit grid by grid. Ray tracing is employed to track the transmission through the flow of supersonic fluids, and a recursive algorithm is derived. The line-of-sight errors and optical path differences produced by the mean density fields were calculated, the phase variances brought from the density fluctuations were computed, and the Strehl ratios were figured out. This method potentially provides a solution for the prediction of aero-optical effects. (C) 2007 Optical Society of America.

关键词： recursive algorithms flow field Grid Numerical methods STREHL RATIO Light DENSITY FLUCTUATIONS through flow supersonic flow optical paths grids Isotropy

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A directional forgetting algorithm based on the decomposition of the information matrix

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AUTOMATICA 2000年第11期36卷 1725-1731页

作者： Cao, LY Schwartz, H Carleton Univ Dept Syst & Comp Engn Ottawa ON K1S 5B6 Canada

A novel algorithm for directional forgetting is proposed based on a matrix decomposition method, which is developed in this paper. This algorithm performs exponential forgetting according to the direction of the data vector, thus preventing the problem known as estimator windup which is a characteristic of the standard exponential forgetting algorithm. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： recursive algorithms least-squares method parameter estimation exponential forgetting directional forgetting

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LINEARIZATION OF MANIPULATOR DYNAMICS USING SPATIAL OPERATORS

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IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS 1993年第1期23卷 239-248页

作者： JAIN, A RODRIGUEZ, G Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA

Linearized dynamics models for manipulators are useful in robot analysis, motion planning, and control applications. Techniques from the spatial operator algebra are used to obtain closed form operator expressions for two types of linearized dynamics models, the linearized inverse and forward dynamics models. Spatially recursive algorithms of O(n) and O(n2) complexity for the computation of the perturbation vector and coefficient matrices for the linearized inverse dynamics model (LIDM) are developed first. Subsequently, operator factorization and inversion identities are used to develop corresponding closed-form expressions for the linearized forward dynamics model (LFDM). Once again, these are used to develop algorithms of O(n) and O(n2) complexity for the computation of the perturbation vector and the coefficient matrices. The algorithms for the LFDM do not require the explicit computation of the mass matrix nor its numerical inversion and are also of lower complexity than the conventional O(n3) algorithms.

关键词： mass matrix perturbation recursive algorithms Coefficient Matrix algorithms dynamics arithmetic operator

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recursive TEMPORAL-SPATIAL INFORMATION FUSION WITH APPLICATIONS TO TARGET IDENTIFICATION

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 1993年第2期29卷 435-445页

作者： HONG, L LYNCH, A HQ AFLC ENIWRIGHT PATTERSON AFBOH 45433

In this paper, centralized/distributed recursive algorithms for temporal-spatial information integration using the Dempster-Shafer technique are developed. Compared with the Bayesian approach, the Dempster-Shafer technique has the strong capability of handling information uncertainties which is especially desired in many applications. In the centralized integration algorithm, all information is pooled into the central processor and integrated. In contrast, the distributed integration algorithm shares the computational burden among the local processors, which increases the computational efficiency The developed algorithms are effectively applied to a target identification problem with three sensors: identification of friend-foe-neutral (IFFN), electronic support measurement (ESM), and infrared search and track (IRST).

关键词： PROCESSOR recursive algorithms Information fusion ELECTRONIC SUPPORT MEASURES Target recognition recursive integral algorithm

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A matrix pseudo-inversion lemma for positive semidefinite hermitian matrices and its application to adaptive blind deconvolution of MIMO systems

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2008年第1期55卷 412-423页

作者： Kohno, Kiyotaka Inouye, Yujiro Kawamoto, Mitsuru Shimane Univ Dept Elect & Control Syst Engn Shimame 6908504 Japan Natl Inst Adv Ind Sci & Technol Technol Informat Res Inst Tsukuba 3058568 Japan

In the simplest case, the matrix inversion lemma gives an explicit formula of the inverse of a positive-definite matrix A added to a rank-one matrix bb(H) as follows: (A + bb(H))(-1) = A(-1) - A(-1) b(1 + b(H) A(-1)b)(-1)b(H) A(-1). It is well known in the literature that this formula is very useful to develop a recursive least-squares algorithm for the recursive identification of linear systems or the design of adaptive filters. We extend this result to the case when the matrix A is singular and present a matrix pseudo-inversion lemma along with some illustrative examples. Such a singular case may occur in a situation where a given problem is overdetermined in the sense that it has more equations than unknowns. This lemma is important in its own right, but in order to show the usefulness of the lemma, we apply it to develop an adaptive superexponential algorithm for the blind deconvolution of multi-input multi-output systems.

关键词： adaptive super-exponential algorithm (SEA) matrix pseudo-inversion lemma recursive algorithms

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Hypoglycemia Early Alarm Systems Based on Multivariable Models

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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 2013年第35期52卷 12329-12336页

作者： Turksoy, Kamuran Bayrak, Elif S. Quinn, Lauretta Littlejohn, Elizabeth Rollins, Derrick Cinar, Ali IIT Dept Biomed Engn Chicago IL 60616 USA IIT Dept Chem & Biol Engn Chicago IL 60616 USA Univ Illinois Coll Nursing Chicago IL 60612 USA Univ Chicago Div Biol Sci Endocrinol Sect Dept Pediat & Med Chicago IL 60637 USA Iowa State Univ Dept Chem & Biol Engn Ames IA 50011 USA

Hypoglycemia is a major challenge of artificial pancreas systems and a source of concern for potential users and parents of young children with Type 1 diabetes (T1D). Early alarms to warn of the potential of hypoglycemia are essential and should provide enough time to take action to avoid hypoglycemia. Many alarm systems proposed in the literature are based on. interpretation of recent trends in glucose values. In the present study, subject specific recursive linear time series models are introduced as a better alternative to capture glucose variations and predict future blood glucose concentrations. These models are then used in hypoglycemia early alarm systems that notify patients to take action to prevent hypoglycemia before it happens. The models developed and the hypoglycemia alarm system are tested retrospectively using T1D subject data. A Savitzky-Golay filter and a Kalman filter are used to reduce noise in patient data. The hypoglycemia alarm algorithm is developed by using predictions of future glucose concentrations from recursive models. The modeling algorithm enables the dynamic adaptation of models to inter/intra-subject variation and glycemic disturbances and provides satisfactory glucose concentration prediction with relatively small error. The alarm systems demonstrate good performance in prediction of hypoglycemia and ultimately in prevention of its occurrence.

关键词： Hypoglycemia alarms diabetes multivariable models process monitoring recursive algorithms

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Methods for Estimating the Required Volume of Resource for Multiservice Access Nodes

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AUTOMATION AND REMOTE CONTROL 2020年第12期81卷 2244-2261页

作者： Stepanov, S. N. Stepanov, M. S. Moscow Tech Univ Commun & Informat Moscow Russia

We construct and study a mathematical model for the distribution of information transmission resource in a multiservice access node. The model considers an arbitrary number of multimedia traffic streams, which differ in the intensity of claims arrival, the amount of resource used to service one claim, and the resource occupation time. The time intervals between the arrival of claims have an exponential distribution with a parameter depending on the number of claims being serviced in the considered flow. We construct a recursive algorithm for evaluating the characteristics. Relations are established between the integral and flow characteristics of the quality of service for the claims. We construct an efficient algorithm for estimating the amount of resource required to service given traffic flows with required quality. The efficiency of the computational procedure is achieved as a result of organizing recursion over the volume of resource and the use of normalized values of state probabilities. We consider a solution to the problem of estimating the required amount of resource for a multiservice node model, which allows to use resource reservation and dynamic distribution mechanisms when servicing elastic traffic. We show numerical examples that illustrate the features of the implementation of the constructed computational procedures.

关键词： multiservice access node Markov models system of equilibrium equations recursive algorithms reservation elastic traffic

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recursive structures and finite impulse response implementations of linear multiuser detectors for an asynchronous CDMA system

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 1998年第9期16卷 1736-1746页

作者： Uppala, SV Sahr, JD Lucent Technol Bell Labs Murray Hill NJ 07974 USA Univ Washington Dept Elect Engn Seattle WA 98195 USA

We present order-recursive structures for implementing the linear decorrelating and linear minimum mean square error (MMSE) detectors in a computationally efficient manner. These infinite memory length, Linear time invariant, noncausal systems can be approximated by implementing them as K-input K-output finite impulse response (FIR) filters. We developed a linear multiuser receiver architecture called a recursive linear multiuser detector which has lower computational and memory requirements then an equivalent tap delay line FIR filter implementation. We establish the tradeoff between window length and bit error rate and find that relatively small window size yields performance indistinguishable from the ideal decorrelating detector and the ideal MMSE detector.

关键词： cyclic reduction FIR filters iterative methods linear decorrelating detector MMSE detector multiuser detection recursive algorithms

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Calibration-free laser-induced plasma analysis of a metallic alloy with self-absorption correction

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APPLIED PHYSICS B-LASERS AND OPTICS 2014年第3期117卷 823-832页

作者： Shirvani-Mahdavi, Hamidreza Shoursheini, Seyede Zahra Gholami, Hamid Dini-Torkamani, Ziba Ghahari-Korani, Sare Islamic Azad Univ Cent Tehran Branch Dept Phys Tehran Iran Alzahra Univ Dept Phys Tehran *** Iran

Identification and concentration measurement of constituent elements of a metallic alloy is demonstrated by calibration-free laser-induced breakdown spectroscopy (CF-LIBS) according to a special peak intensity-based model and considering the self-absorption effect. In this procedure, which is based on the line pair ratio method, the effect of line widths, though needs to be theoretically considered, may be approximately ignored. This is mainly true for the multiplet lines, but this property, in the case of some generic spectral lines in a measured spectrum, can be sometimes regarded. Initially, the optical penetration depth and therefrom self-absorption coefficient of each selected spectral line is calculated using the experimental (self-absorbed) intensity of the line. Then, the true (non-self-absorbed) intensity, which is basis of the conventional CF-LIBS calculation, is obtained through a recursive algorithm implemented by the MATLAB programming. In the experimental examination, the recorded spectrum reflects that the metallic alloy is consisted of gold, copper and silver. The concentration of elements is calculated with and without regarding self-absorption correction using 27 trios of spectral lines related to the elements. The average concentrations signify that the measurement error relative to the certified value for the concentration of the gold is modified from 3.56 % in the normal way to 0.34 % after applying self-absorption correction.

关键词： Spectral lines absorption effect recursive algorithms METAL ALLOY self absorption Egoism concentration measurements absorption correction

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