Like many other developed cities, Hong Kong has been suffering from acute problems of urban decay. To solve this building crisis, knowledge of the condition profile of all buildings in Hong Kong is vital. A territory-...
详细信息
It is shown that, in the pattern recognition problem with two nonoverlapping classes, the matrices of estimates of the object closeness are described by a metric. The transition to the algebraic closure of the model o...
详细信息
It is shown that, in the pattern recognition problem with two nonoverlapping classes, the matrices of estimates of the object closeness are described by a metric. The transition to the algebraic closure of the model of recognizing operators of finite degree corresponds to the application of a special transformation of this metric. It is proved that the minimal degree correct algorithm can be found as a polynomial of a special form. A simple criterion for testing classification implementations is obtained.
作者:
Kirubarajan, T.Estimation
Tracking and Fusion Research Laboratory Electrical and Computer Engineering Department McMaster University Hamilton ON Canada
A number of performance bounds like, for example, Cramer-Rao Lower Bound and Weiss-Weinstein Bound, have been derived to quantify the performance achievable by any algorithm in state estimation problems. These bounds ...
详细信息
ISBN:
(纸本)9780819471598
A number of performance bounds like, for example, Cramer-Rao Lower Bound and Weiss-Weinstein Bound, have been derived to quantify the performance achievable by any algorithm in state estimation problems. These bounds are evaluated at the ground truth, which means that the exact bound is available only for simulation-based or instrumented real experiments. Also, a number of assumptions on the statistics, state models and their evolution over time are made in order to facilitate the derivation of these complex bounds. As a result, these bounds are at best approximations of achievable performance. In addition, these bounds are often computationally cumbersome, if at all possible, to evaluate in realistic multisensor-multitarget tracking problems. In spite of these limitations, the bounds have been used successfully for performance prediction, tracker evaluation and sensor resource management. In this short paper, we briefly discuss the usefulness of theoretical bounds as realistic performance evaluation measures in real-world tracking problems.
An algebra over recognition algorithms supplemented with a normalization operation (under various definitions) and the division operation is investigated. Correctness criteria for various algebraic closures are obtain...
详细信息
Relying on a simple flag-assisted mechanism, a multigroup priority queueing (MGPQ) medium access control (MAC) protocol is proposed for the wireless networks with multipacket reception ( MPR). The proposed MGPQ scheme...
详细信息
Relying on a simple flag-assisted mechanism, a multigroup priority queueing (MGPQ) medium access control (MAC) protocol is proposed for the wireless networks with multipacket reception ( MPR). The proposed MGPQ scheme is capable of overcoming two major performance bottlenecks inherent in the existing MPR MAC protocols. First, the proposed solution can automatically produce the list of active users by observing the network traffic conditions, remove the need of active user estimation algorithm, and thus can largely reduce the algorithm complexity. Second, the packet blocking constraint imposed on the active users for keeping compliant with prediction is relaxed. As a result, the proposed MGPQ is not only applicable to both homogeneous and heterogeneous cases, but also outperforms the existing MPRMAC protocols. Simulation results show that the network throughput can be improved by 40% maximum and 14% average as compared with the well- known dynamic queue (DQ) MAC protocol.
Radio-over-fibre (ROF) has received increasing attention for its ability to enable broadband wireless access. This fibre-based wireless access scheme meets the demand for broadband service by integrating the high capa...
详细信息
Radio-over-fibre (ROF) has received increasing attention for its ability to enable broadband wireless access. This fibre-based wireless access scheme meets the demand for broadband service by integrating the high capacity of optical networks with the flexibility of radio networks (the optical and wireless channels are concatenated with one another). There are, however, impairments that come with this appealing technology. The nonlinear distortion of the optical link and the multipath dispersion of the wireless channel are two of the major factors. In order to limit the effects of these distortions, estimation, and subsequently equalisation, of the concatenated fibre-wireless channel needs to be done. An estimation algorithm for the fibre-wireless uplink in a multiuser code division multiple access (CDMA) environment is presented using pseudonoise training sequences. It has already been shown by Fernando et al. (2001) that identification of the fibre-wireless uplink is possible in a single user CDMA environment. However, the more difficult task of identification in a multiuser spread spectrum environment, which is more realistic, is shown. In the multiuser case, the cumulative effect of multiuser interference, multipath dispersion, nonlinear distortion and noise should all be handled together which makes it more challenging. Numerical evaluations of the developed algorithm show that a good estimation of both the linear and nonlinear systems is possible in the presence of 16 independent users and an signal-to-noise ratio (SNR) of 22 dB. The estimation accuracy increases with the length of the PN sequence.
An implementation of Cavity Parameters estimation System (CPES) is presented. Main idea of the CPES is to support the LLRF - Low Level Radio Frequency system for FLASH laser in DESY. Algebraic, complex model of the LL...
详细信息
ISBN:
(纸本)9781424408122
An implementation of Cavity Parameters estimation System (CPES) is presented. Main idea of the CPES is to support the LLRF - Low Level Radio Frequency system for FLASH laser in DESY. Algebraic, complex model of the LLRF system is proposed. For a given model structure the input-output relation of the real plant with unknown parameters is applied. The over-determined matrix equation is created covering the long enough measurement range with a solution according to the least squares method. A base function approximation by cubic B-spline set is applied to estimate the time-varying cavity detuning during the pulse. An implementation in DSP processor of the matrix equation solution and cavity parameters estimation algorithm is presented. A comparison between Matlab and DSP computation error is presented.
This paper considers the problem of optimizing the burst format of packet transmission to perform enhanced-accuracy estimation of Doppler-shift and Doppler-rate of the carrier of the received signal, due to relative m...
详细信息
This paper considers the problem of optimizing the burst format of packet transmission to perform enhanced-accuracy estimation of Doppler-shift and Doppler-rate of the carrier of the received signal, due to relative motion between the transmitter and the receiver. Two novel burst formats that minimize the Doppler-shift and the Doppler-rate Cramer-Rao bounds (CRBs) for the joint estimation of carrier phase/Doppler-shift and of the Doppler-rate are derived, and a data-aided (DA) estimation algorithm suitable for each optimal burst format is presented. Performance of the newly derived estimators is evaluated by analysis and by simulation, showing that such algorithms attain their relevant CRBs with very low complexity, so that they can be directly embedded into new-generation digital modems for satellite communications at low SNR.
To meet future pollutant emissions Standards, it is crucial to be able to estimate the cycle by cycle in-cylinder mass and the composition of the combustion chamber charge. This charge consists of residual gas from th...
详细信息
To meet future pollutant emissions Standards, it is crucial to be able to estimate the cycle by cycle in-cylinder mass and the composition of the combustion chamber charge. This charge consists of residual gas from the previous cycle, fresh air and fuel. Consequently, the estimation of the fresh air mass based on total in-cylinder mass is a function of the residual gas fraction. This estimation is essential to compute the fuel mass to be injected. This paper proposes two observers, based on a physical approach, that estimate the in-cylinder mass and composition using the cylinder pressure. To test the estimator, several parameters are varied, especially the cylinder pressure offset compensation and the exhaust gases temperature.
This paper investigates the joint maximum likelihood (ML) estimation of the carrier frequency offset, timing error, and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization pro...
详细信息
This paper investigates the joint maximum likelihood (ML) estimation of the carrier frequency offset, timing error, and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization process is assisted by a training sequence appended in front of each burst and composed of alternating binary symbols. The use of this particular pilot pattern results into an estimation algorithm of a. ordable complexity that operates in a decoupled fashion. In particular, the frequency offset is measured first and independently of the other parameters. Timing and phase estimates are subsequently computed through simple closed-form expressions. The performance of the proposed scheme is investigated by computer simulation and compared with Cramer-Rao bounds. It turns out that the estimation accuracy is very close to the theoretical limits up to relatively low signal-to-noise ratios. This makes the algorithm well suited for turbo-coded transmissions operating near the Shannon limit. Copyright (c) 2007 M. Morelli and A. A. D'Amico.
暂无评论