检索结果-内蒙古大学图书馆

On Queue Length and Link Buffer Size estimation in 3G/4G Mobile Data Networks

IEEE TRANSACTIONS ON MOBILE COMPUTING 2014年第6期13卷 1298-1311页

作者： Chan, Stanley C. F. Chan, K. M. Liu, K. Lee, Jack Y. B. Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China

The emerging mobile data networks fueled by the world-wide deployment of 3G, HSPA, and LTE networks created new challenges for the development of Internet applications. Unlike their wired counterpart, mobile data networks are known to exhibit highly variable bandwidth. Moreover, base stations are often equipped with large buffers to absorb bandwidth fluctuations to prevent unnecessary packet losses. Consequently to optimize protocol performance in mobile data networks it is essential to be able to accurately characterize two key network properties: queue length and buffer size of the bottleneck link. This work tackles the challenge in estimating these two network properties in modern mobile data networks. Using extensive trace-driven simulations based on actual bandwidth trace data measured from production mobile data networks, we show that existing queue-length and link buffer size estimation algorithms no longer work well in bandwidth-varying networks. We develop a novel sum-of-delays algorithm which incorporates the effect of bandwidth variations into its estimation. Extensive trace-driven simulation results show that it can accurately estimate the queue length and link buffer size under both fixed and varying bandwidth conditions, outperforming existing algorithms by up to two orders of magnitude.

关键词： Queue length link buffer size estimation algorithm sum-of-delays mobile data networks passive and active estimations

来源：评论

学校读者我要写书评

暂无评论

Forward-backward processing for efficient underground channel estimation in 60 GHz MISO FBMC systems

引用

ELECTRONICS LETTERS 2019年第2期55卷 92-+页

作者： Belaoura, W. Ghanem, K. Nedil, M. Bousbia-Salah, H. Ecole Natl Polytech Dept Elect Engn Algiers Algeria CDTA Algiers Syst Architecture Lab Algiers Algeria UQAT Underground Commun Res Lab LRTCS Rouyn Noranda PQ Canada

In this Letter, a novel low complexity sparse channel estimation method based on forward-backward processing is proposed for mm-Wave underground channel incorporating a $2\times 1$2x1 space-time-block coding filter bank multi-carrier (STBC-FBMC) system, which employs quadrature amplitude modulation. The proposed estimation algorithm relies on the idea of the channel support forward selection and backward removal, which iteratively expands and compresses the support estimate, hence improving the ability to cover up for the errors made in the conventional orthogonal matching pursuit (OMP) algorithm. By contrast to the latter, the most innovative feature of the proposed approach is its capability of effective channel reconstruction without prior information of the sparsity level and its adaptive step size method to approach the true sparsity level. The proposed approach is shown to achieve a higher estimation accuracy than OMP alternative.

关键词： channel bank filters space-time codes channel estimation block codes filtering theory OFDM modulation quadrature amplitude modulation iterative methods novel low complexity sparse channel estimation method forward-backward processing underground channel incorporating $2\times 1$ space-time-block coding filter bank multicarrier system STBC-FBMC quadrature amplitude modulation estimation algorithm channel support backward removal support estimate conventional orthogonal matching pursuit algorithm effective channel reconstruction adaptive step size method higher estimation accuracy efficient underground channel estimation 60 GHz MISO FBMC systems frequency 60 0 GHz

来源：评论

学校读者我要写书评

暂无评论

Parameter estimation in continuous-time stochastic systems with correlated noises using the Kalman filter and Least Squares Method

引用

IFAC-PapersOnLine 2018年第13期51卷 309-313页

作者： Jesica, Escobar Poznyak, Alexander Instituto Politecnico Nacional ESIME Zac UPALM Av IPN S/N Mexico Department of Automatic Control CINVESTAV-IPN A.P. 14-740 D.F.07000 Mexico

In this paper we present the problem of parameter estimation in continuous-time stochastic systems under coloured or correlated noises. The Least Squares Method (LSM) is a classical approach, but the estimation usually presents bias in stochastic systems. Here we combine this technique with a Kalman filter, that will minimize the noise effect, and will improve the estimation algorithm performance. The Instrumental Variable method will be implemented too, in order to analyse which method is more suitable for systems with coloured noises. The effectiveness of the proposed methods will be illustrated with a numerical example. © 2018

关键词： Continuous time systems Electric filters Kalman filters Least squares approximations Numerical methods Parameter estimation Stochastic systems White noise Classical approach Coloured noise Continuous time Correlated noise estimation algorithm Instrumental variable methods Least squares estimation Least squares methods

来源：评论

学校读者我要写书评

暂无评论

Highway Traffic State estimation with Mixed Connected and Conventional Vehicles

引用

IFAC-PapersOnLine 2016年第3期49卷 309-314页

作者： Bekiaris-Liberis, Nikolaos Roncoli, Claudio Papageorgiou, Markos Department of Production Engineering & Management Technical University of Crete Chania73100 Greece

A macroscopic model-based approach for estimation of the traffic state, specifically of the (total) density and flow of vehicles, is developed for the case of “mixed” traffic, i.e., traffic comprising both ordinary and connected vehicles. The development relies on the following realistic assumptions: (i) The density and flow of connected vehicles are known at the (local or central) traffic monitoring and control unit on the basis of their regularly reported positions; and (ii) the average speed of conventional vehicles is roughly equal to the average speed of connected vehicles. Thus, complete traffic state estimation (for arbitrarily selected segments in the network) may be achieved by merely estimating the percentage of connected vehicles with respect to the total number of vehicles. A model is derived, which describes the dynamics of the percentage of connected vehicles, utilizing only well-known conservation law equations that describe the dynamics of the density of connected vehicles and of the total density of all vehicles. Based on this model, which is a linear parameter-varying system, an estimation algorithm for the percentage of connected vehicles is developed employing a Kalman filter. The estimation methodology is validated through simulations, using a second-order macroscopic traffic flow model as ground truth for the traffic state, as well as using real microscopic traffic data collected within the Next Generation SIMulation (NGSIM) program. © 2016

关键词： Street traffic control estimation Highway traffic control Linear systems Motor transportation State estimation Vehicles Connected vehicles estimation algorithm estimation methodologies Linear parameter varying systems Macroscopic traffic flow model Number of vehicles Traffic monitoring Traffic state estimation

来源：评论

学校读者我要写书评

暂无评论

On the Effect of Stabilization Methods for Quaternion Invariants on the Uncertainty in Optimization-based estimation⁎

引用

IFAC-PapersOnLine 2018年第25期51卷 116-121页

作者： Girrbach, Fabian Hol, Jeroen D. Zandbergen, Raymond Verschueren, Robin Bellusci, Giovanni Diehl, Moritz Xsens Technologies B.V. EnschedePR7521 Netherlands University of Freiburg Freiburg79110 Germany

The handling of 3D orientations is a common element in many problems that arise in the estimation and control of dynamic systems. Over-parametrizations such as unit quaternions are commonly used to avoid singularities but come with the property of an invariant which needs to be preserved. By using numerical optimization methods, these invariants are subject to numeric errors and require stabilization. In this work, we adopt methods known from optimal control for the problem of state estimation. We present an optimization-based attitude estimator using the measurements of an inertial measurement unit and evaluate the performance of a first-order stabilization of the invariant by modifying the dynamics. The uncertainties of the estimator are analyzed for different configurations of the proposed stabilization. Finally, we show how the stabilization affects the estimation of parameters and justify the use of an additional equality constraint for the invariant to yield more robust and consistent results. © 2018

关键词： Stabilization Numerical methods Optimization Uncertainty analysis Attitude algorithms estimation algorithm estimation of parameters Inertial measurement unit invariants Numerical optimizations Optimal estimations Stabilization methods

来源：评论

学校读者我要写书评

暂无评论

estimation of the TQ-complexity of chaotic sequences

引用

IFAC-PapersOnLine 2015年第11 11期48卷 1049-1055页

作者： Makarenko, A.V. Constructive Cybernetics Research Group P.O. Box 560 Moscow101000 Russia Institute of Control Sciences Russian Academy of Sciences Moscow Russia

A new approach is proposed to the quantitative estimation of the complexity of multidimensional discrete sequences in terms of the shapes of their trajectories in the extended space of states. This approach is based on the study of the structural properties of sequences and is suitable for estimating the complexity of both chaotic and stochastic sequences. It is constructed on the method, proposed earlier by the author, of symbolic CTQ-analysis of multidimensional discrete sequences and mappings. The algorithm proposed manipulates not only the frequency of occurrence of symbols, but also takes into account their sequence order. An example (financial time series) is given that demonstrates the application of the tools developed. © 2015

关键词： Time series analysis Chaos theory Computational complexity Digital control systems Discrete time control systems Financial data processing Stochastic systems Chaotic sequence Discrete time systems Discrete sequences estimation algorithm Financial time series New approaches Quantitative estimation Stochastic complexity

来源：评论

学校读者我要写书评

暂无评论

Frequency estimation of a sinusoidal signal with time-varying amplitude*

引用

IFAC-PapersOnLine 2017年第1期50卷 12880-12885页

作者： Vedyakov, Alexey A. Vediakova, Anastasiia O. Bobtsov, Alexey A. Pyrkin, Anton A. Aranovskiy, Stanislav V. Department of Control Systems and Informatics ITMO University Kronverkskiy pr. 49 St. Petersburg197101 Russia Department of Computer Applications and Systems St.Petersburg State University 7/9 Universitetskaya nab. St. Petersburg199034 Russia Laboratory “Control of Complex Systems” Institute of Problems of Mechanical Engineering V.O. Bolshoj pr. 61 St. Petersburg199178 Russia CentraleSupélec IETR Avenue de la Boulaie Cesson-Sévigné35576 France

This paper is devoted to frequency estimation of a sinusoidal signal with a time-varying amplitude. The amplitude can take zero values, but should be known and bounded. The first order linear regression model is obtained. The estimation algorithm has been constructed basing on standard gradient approach. It is shown that the frequency estimation error converges to zero exponentially fast. The described algorithm does not require measuring or calculating derivatives of the input signal. The efficiency of the proposed approach is demonstrated through a set of numerical simulations. © 2017

关键词： Frequency estimation Continuous time systems Linear regression Continuous time estimations estimation algorithm Frequency estimation errors Gradient approach Gray box models Linear regression models Sinusoidal signals Time domain identification

来源：评论

学校读者我要写书评

暂无评论

Assessing the estimation of nearly singular covariance matrices for modeling spatial variables

引用

ELECTRONIC JOURNAL OF STATISTICS 2023年第2期17卷 3287-3315页

作者： Perez, Javier Acosta, Jonathan Vallejos, Ronny Univ Tecn Federico Santa Maria Dept Matemat Valparaiso Chile Pontificia Univ Catolica Chile Dept Estadist Santiago Chile

Spatial analysis commonly relies on the estimation of a covariance matrix associated with a random field. This estimation strongly impacts the prediction where the process has not been observed, which in turn influences the construction of more sophisticated models. If some of the distances between all the possible pairs of observations in the plane are small, then we may have an ill-conditioned problem that results in a nearly singular covariance matrix. In this paper, we suggest a covariance matrix estimation method that works well even when there are very close pairs of locations on the plane. Our method is an extension to a spatial case of a method that is based on the estimation of eigenvalues of the unitary matrix decomposition of the covariance matrix. Several numerical examples are conducted to provide evidence of good performance in estimating the range parameter of the correlation structure of a spatial regression process. In addition, an application to macroalgae estimation in a restricted area of the Pacific Ocean is developed to determine a suitable estimation of the effective sample size associated with the transect sampling scheme.

关键词： Spatial process nearly singular covariance ma-trix Vandermonde matrix estimation algorithm

来源：评论

学校读者我要写书评

暂无评论

State estimation Under Correlated Partial Measurement Losses: Implications for Weight Control Interventions

引用

IFAC-PapersOnLine 2017年第1期50卷 13532-13537页

作者： Guo, Penghong Rivera, Daniel E. Savage, Jennifer S. Downs, Danielle S. School for Engineering of Matter Transport and Energy Arizona State University TempeAZ85281 United States Center for Childhood Obesity Research and the Department of Nutritional Sciences Penn State University University Park PA United States Exercise Psychology Laboratory Department of Kinesiology Penn State University University Park PA United States

The growing prevalence of obesity and related health problems warrants immediate need for effective weight control interventions. Quantitative energy balance models serve as powerful tools to assist in these interventions, as a result of their ability to accurately predict individual weight change based on reliable measurements of energy intake and energy expenditure. However, the data collected in most existing weight interventions is self-monitored; these measurements often have significant noise or experience losses resulting from participant non-adherence, which in turn, limits accurate model estimation. To address this issue, we develop a Kalman filter-based estimation algorithm for a practical scenario where on-line state estimation for weight, or energy intake/expenditure is still possible despite correlated partial data losses. To account for non-linearities in the models, an algorithm based on extended Kalman filtering is also developed for sequential state estimation in the presence of missing data. Simulation studies are presented to illustrate the performance of the algorithms and the potential benefits of these techniques in real-life interventions. © 2017

关键词： Extended Kalman filters estimation Filtration Kalman filters Nutrition State estimation Weight control Energy balance models estimation algorithm Extended Kalman filtering Intermittent measurements Interventions Multiple missing measurements Obesity Reliable measurement

来源：评论

学校读者我要写书评

暂无评论

Model Ship Control and estimation of Full-scale Propeller Torque in Wind and Waves

引用

IFAC-PapersOnLine 2018年第29期51卷 201-206页

作者： Ueno, Michio Suzuki, Ryosuke Tsukada, Yoshiaki National Maritime Research Institute MitakaTokyo181-0004 Japan

This paper presents free-running model ship test data estimating full-scale propeller torque fluctuating in wind and waves. The model ship control using the auxiliary thruster ensures the similarity of model ship motion to full scale that leads the similar propeller situation The wind load simulator controls six duct fans on the model ship for simulating the wind loads. The estimation algorithm converts the measured model propeller torque to full scale assuming no scale effect on the wave component in the effective inflow velocity to propeller. The analysis reveals the differences of the fluctuating propeller torque between model and full-scale ships. © 2018

关键词： Ship propulsion Aerodynamic loads Propellers Ship models Torque Wind stress Auxiliary thrusters estimation algorithm Inflow velocity Scale effects Ship control Ship motion Wave components Wind load

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：