Multiscale modeling and estimation of Poisson processes withapplication to photon-limited imaging

Many important problems in engineering and science are well-modeled by Poisson processes. In many applications it is of great interest to accurately estimate the intensities underlying observed Poisson data. In particular, this work is motivated by photon-limited imaging problems. This paper studies a new Bayesian approach to Poisson intensity estimation based on the Haar wavelet transform. It is shown that the Haar transform provides a very natural and powerful framework for this problem. Using this framework, a novel multiscale Bayesian prior to model intensity functions is devised. The new prior leads to a simple Bayesian intensity estimation procedure. Furthermore, we characterize the correlation behavior of the new prior and show that it has 1/f spectral characteristics. The new framework is applied to photon-limited image estimation, and its potential to improve nuclear medicine imaging is examined     

State estimation of output-decoupled complex systems withapplication to fluid pipeline

Most industrial processes are complex systems, characterized by nonlinearity, high order, and even implicit dynamics. The design of a Luenberger-type observer or an extended Kalman filter for state estimation of such systems presents, in general, considerable difficulties. The authors show that a state estimator can be designed and implemented very easily if the system is output-decoupled, as is often the case in process monitoring and control applications. Simulation study and experiments on an experimental water pipeline show that the proposed estimator works very well. Its estimation accuracy is nearly the same as that of an extended Kalman filter, while its computational expenditure is almost as small as the real-time system model     

Parameter estimation of cyclostationary AM time series withapplication to missing observations

Time series with systematic misses occur often in practice and can be modeled as amplitude modulated ARMA processes. With this as a motivating application, modeling of cyclostationary amplitude modulated time series is addressed in the paper. Assuming that the modulating sequence is (almost) periodic, parameter estimation algorithms are developed based on second- and higher order cumulants of the resulting cyclostationary observations, which may be corrupted by any additive stationary noise of unknown covariance. If unknown, the modulating sequence can be recovered even in the presence of additive (perhaps nonstationary and colored) Gaussian, or any symmetrically distributed, noise. If the ARMA process is nonGaussian, cyclic cumulants of order greater than three can identify (non)causal and (non)minimum phase models from partial noisy data. Simulation experiments corroborate the theoretical results     

Mixed lumped and distributed network applied to superconductingthin-film broadband impedance transforming

In this paper, a detailed analysis of the properties of mixed lumped and distributed (MLD) lossless elements is first carried out. It is found that such networks can be used as extreme impedance transformers between source and load impedances without large variations in wave impedance values. Then, the lossy transformation technique (LTT) is extended to the design of MLD lossy networks. Finally, to exhibit the practical use of the new method, three examples are given for transforming extremely low input impedance of a superconducting device to a 50 Ω microwave system with the MLD networks. The outstanding advantage using this method is that transformers can be made considerably shorter than by common methods and still physically realizable. The length of the building element is reduced from λ/4 to λ/16     

Contribution to the synthesis of distributed RC networks

On using a special frequency transformation, a theorem on the synthesis of uniformly distributed RC networks is derived. A network section is introduced which extends the range of realisability of transfer zeros.     

Control of transient effects in distributed and lumped Ramanamplifiers

A robust control scheme for suppressing transients in both lumped and distributed Raman amplifiers is demonstrated. The control method uses only output power monitoring and holds gain fluctuations on surviving channels to <±0.06 dB in an experiment     

Minimization of delay and crosstalk in high-speed VLSIinterconnects

Design optimization of time responses of high-speed VLSI interconnects modeled by distributed coupled transmission line networks is presented. The problem of simultaneous minimization of crosstalk, delay and reflection is formulated into minimax optimization. Design variables include physical/geometrical parameters of the interconnects and parameters in terminating/matching networks. A recently published simulation and sensitivity analysis technique for multiconductor transmission lines is expanded to directly address the VLSI interconnect environment. The new approach permits efficient physical/geometrical oriented interconnect design using exact gradient based minimax optimization. Examples of interconnect optimization demonstrate significant reductions of crosstalk, delay, distortion and reflection at all vital connection ports. The technique developed is an important step towards optimal design of circuit interconnects for high-speed digital computers and communication systems     

Empirical equations on electrical parameters of coupled microstriplines for crosstalk estimation in printed circuit board

Empirical equations for the self and mutual capacitance and inductance (C_s, C_m, L_s, L_m) of coupled microstrip lines in a printed circuit board were derived from the numerical simulation results to reduce the computation time for crosstalk estimation. Comparison of the measured C_s, C_m , L_s and L_m values with the derived empirical equations showed good agreements. Also in the near-end and far-end crosstalks, good agreements were obtained between measurements and the derived empirical equations. Microstrip lines embedded in the homogeneous dielectric material as well as those in the inhomogeneous medium with one side exposed to air were considered in this work. Based on the derived empirical equations, a design guide on the spacing between microstrip lines was established     

Novel approach to multicoupled-cavity filter sensitivity and group delay computation

Novel formulas for simulation and sensitivity analysis of multicoupled-cavity filters are presented. Only one real LU factorisation and simple utilisation of the corresponding original network analysis permit exact first-order sensitivity computations, group delay calculation and loss prediction.     

A new and efficient approach for estimating the accurate time-domain response of single and capacitive coupled distributed RC interconnects

This paper describes a novel yet highly efficient approach for estimating the time-domain response of capacitive coupled distributed RC interconnects. By using this method, the voltage signal at any particular point in such wires can be accurately and quickly obtained with very low computational cost. The proposed model exhibits a very good agreement with HSPICE simulations with worst-case error less than 3% and can be readily implemented in CAD analysis tools. This paper also presents an efficient model to estimate the capacitive crosstalk in high-speed very large scale integration (VLSI) circuits. Experimental results show that the maximum error of our peak noise predictions is less than 2.5%. In addition, this work presents an efficient artificial neural network (ANN)-based technique for modeling the time-domain response of interconnects and crosstalk noise. While existing fast noise estimation metrics may overestimate or underestimate the coupling noise, the simulation results demonstrate the ability of this approach to successfully predict coupling noise with a very good accuracy as compared to HSPICE in modest CPU times. Thereby, the proposed models and techniques can be used to predict the signal integrity for designing high-speed and high-density VLSI circuits.     

Exact solution for capacitive compensation of the RC potential divider with lumped stray capacitances to earth

Serious shortcomings of RC wideband dividers for high voltages can be overcome by suitably graded compensation of stray capacitance. The general case of the lumped-circuit-element RC divider is analysed, and the exact solution for graded capacitive compensation for any distribution of lumped stray capacitance is given.     

Scan flip-flops with on-line testing ability with respect to input delay and crosstalk faults

We propose a possible modification to the internal structure of scan flip-flops, which allows the online detection of delay and crosstalk faults affecting their input. Our solution allows to obtain, together with the flip-flop output datum, an indication denoting whether or not the provided datum is incorrect, because of an input crosstalk or delay fault. The proposed solution features self-checking ability with respect to a wide set of possible internal faults, including node stuck-ats, transistor stuck-ons and stuck-opens, resistive bridgings, delays, transient and crosstalk faults.     

H2 inferential filtering, prediction, and smoothing withapplication to rolling mill gauge estimation

A new minimum mean square error optimal linear estimation problem is considered where no direct measurement of the output to be estimated is available. The optimal filter, predictor, and smoother are derived for this case where outputs must be inferred from available measurements. The results cover the usual Wiener or Kalman filtering problems and also optimal deconvolution estimation problems. However, they also apply to the situation, often found in industry, where estimates of signals are required that can only be determined from secondary measurements. A weighted H₂ cost-function is minimized where the weighting function can be chosen to improve the robustness of the solution. The optimal estimators are derived both for stable and for unstable signal source models. A signal-processing application is considered in detail to demonstrate the use of the optimal filter. The gauge control problem in metal rolling mills is discussed where only force measurements are available     

Modeling of interconnect capacitance, delay, and crosstalk in VLSI

Increasing complexity in VLSI circuits makes metal interconnection a significant factor affecting circuit performance. In this paper, we first develop new closed-form capacitance formulas for two major structures in VLSI, namely: (1) parallel lines on a plane and (2) wires between two planes, by considering the electrical flux to adjacent wires and to ground separately. We then further derive closed-form solutions for the delay and crosstalk noise. The capacitance models agree well with numerical solutions of three-dimensional (3-D) Poisson equation as well as measurement data. The delay and crosstalk models agree well with SPICE simulations     

Analysis of throughput and delay of a high-speed slotted ring basedon lumped modeling

A high-speed slotted ring network with a single buffer at each station is studied. For performance analysis, the authors investigate its throughput and mean delay characteristics based on a lumped model in which all stations are aggregated at a single point on the ring with their relative positions preserved     

On wavelet denoising and its applications to time delay estimation

The application of dyadic wavelet decomposition in the context of time delay estimation is investigated. We consider a model in which the source signal is deterministic and the received sensor outputs are corrupted by additive noises. Wavelet denoising is exploited to provide an effective solution for the problem. Denoising is first applied to preprocess the received signals from two spatially separated sensors with an attempt to remove the contamination, and the peak of their cross correlation function is then located from which the time delay between the two signals can be derived. A novel wavelet shrinkage/thresholding technique for denoising is introduced, and the performance of the algorithm is analyzed rigorously. It is proved that the proposed method achieves global convergence with a high probability. Simulation results also corroborate that the technique is efficient and performs significantly better than both the generalized cross correlator (GCC) and the direct cross correlator (CC)     

Comparative investigation on numerical de-embedding techniques forequivalent circuit modeling of lumped and distributed microstripcircuits

A so-called "short-open calibration" (SOC) technique is applied together with two existing numerical de-embedding techniques for equivalent circuit modeling of microstrip circuits based on a full-wave method-of-moments (MoM) algorithm. A stub-loaded microstrip line discontinuity with both electrically short (lumped) and long (distributed) stub lengths is extensively studied in terms of its Z-matrix circuit model. Our obtained results show that the SOC scheme allows an accurate calibration of all the potential error terms out of the core circuit network, thereby avoiding numerical noise-related behaviors regardless of either lumped or distributed circuits, which are nevertheless observed for the two existing techniques     

一种分布式目标波达方向估计方法

本文提出一种在多径情况下,利用广义阵列流形的特点,通过求解矩阵的广义特征值分解,不用进行谱峰搜索或多维参数搜索,直接由广义特征值得到分布式目标波达方向（DOA）估计的方法。该方法的估计性能对信号源的分布特性优于MUSIC方法。