Roland Priemer

University of Illinois Chicago | UIC · Electrical and Computer Engineering Department

The fetal phonocardiogram, which is the acoustic recording of mechanical activity of the fetal heart, facilitates the measurement of the instantaneous fetal heart rate, beat-to-beat differences and duration of systolic and diastolic phases. These measures are sensitive indicators of cardiac function, reflecting fetal well-being. This paper provides...

Almost all cardiac abnormalities manifest themselves as murmurs in a phonocardiogram (PCG). The location of a murmur in the PCG over a cardiac cycle depends on the underlying cardiac abnormality. Locating murmurs with respect to the cardiac cycle is useful for diagnosing cardiac dysfunction. Locating murmurs is difficult due to spectral similarity...

Illegal duplication and distribution of digital multimedia content over the Internet has been prevalent over the past years. Commercial businesses face millions of dollars in lost revenue each year due to these activities. The traditional approach to data protection is to apply encryption and scrambling. However, these methods alone are not adequat...

Analysis of individual noise sources in pre-nanometer circuits cannot take into account the evolving reality of multiple noise sources interacting with each other. Noise measurement made at an evaluation node will reflect the cumulative effect of all the active noise sources, while individual and relative severity of various noise sources will dete...

The time interval between the aortic (A2) and the pulmonary (P2) components of the second heart sound (S2) is an indicator of pulmonary arterial pressure. However, knowledge of the A2 and P2 components of the S2 sound is difficult to obtain due to their temporal overlap and significant spectral similarity. In this work, we aim to extract the A2 and...

Convergence of blind delayed source separation algorithms, which use constant learning rates, is known to be slow. We propose a fuzzy logic based approach to adaptively select the learning rates, for estimates of delays and cross-weights, in the blind delayed source separation algorithm. We make use of the state of independence of the separated out...

In the past decade there have been significant efforts to analyze and solve signal integrity issues in pre-nanometer circuits. However, most of these techniques apply to single noise source, and cannot take into account the evolving reality of multiple noise sources interacting with each other. With the scaling of the technology into nanometer regi...

This paper presents a snore recorder that can separate snores from their delayed mixtures. This is useful to study the snore sounds of individuals when these sounds occur in a normal in-home sleeping environment, where two people are sleeping together and both produce sounds. Based on methods for blind source separation, we give a snore separator t...

The time interval between the aortic (A2) and pulmonary (P2) components of the second heart sound (S2) is an indicator of the presence and severity of several cardiac abnormalities. However, in many cases identification of the A2 and P2 components is difficult due to their temporal overlap and significant spectral similarity. In this work, we prese...

Segmentation of the phonocardiogram into its major sound components is the first step in the automated diagnosis of cardiac abnormalities. Almost all of the existing phonocardiogram segmentation algorithms utilize absolute amplitude or frequency characteristics of heart sounds, which vary from one cardiac cycle to the other and across different pat...

Segmentation of the phonocardiogram (PCG) into its major sound components is the first step in automated diagnosis of cardiac abnormalities. Almost all the existing PCG segmentation algorithms are based upon amplitude or frequency characteristics, of the heart sounds, that vary from one cardiac cycle to the other and across different patients. The...

Physiological sounds exhibit a variety of waveforms and hence, their probability density functions (pdf) show a wide variation in their shapes ranging from subGaussian to superGaussian to multimodal. In blind source separation (BSS) applications, where extraction of cardiac sounds from their mixtures is the main objective, assuming a particular den...

Linear observers play an important role in modern control theory and practice. A systematic design method of fuzzy observers would be important for fuzzy control as well. The fuzzy observer is designed by solving linear matrix inequalities (LMI) that represent control performance such as disturbance rejection and robust stability. Our approach in d...

The phonocardiogram (PCG) is a mixture of sounds produced by several cardiac structures and hemodynamic activities. Methods such as time segmentation of the heart sound into, for example, the S1 and S2 sounds, or spectral segmentation into frequency bands do not result in sounds produced by individual cardiac structures. Without any prior knowledge...

A method is presented to non-invasively separate the fetal phonocardiograms (FPCG) of the fetuses in a multiple fetus pregnancy. The method uses a device like a stethoscope. We assume that the phonocardiograms of the fetuses are statistically independent. Results of simulations are included in the paper.

In this paper we present a new method of compensating for complex multipath channel fading in blind multiuser detection for DS-CDMA communication. This compensation allows for the use of different chip pulse shapes. The compensation is based on the incorporation of priors derived from the FFT of the pulse shape. The system employs detectors that in...

We give a random optimization (RO) algorithm to optimize a real-valued function of n real variables. During the optimization process, interpolation points are examined to follow valleys, and jumps to new starting points are executed to avoid numerous iterations in local minima. Convergence with probability one to the global minimum of a function is...

In this paper we examine the impact of channel fading on the bit error rate of a DS-CDMA communication system. The system employs detectors that incorporate neural networks effecting methods of independent component analysis (ICA), subspace estimation of channel noise, and Hopfield type neural networks. The Rayleigh fading channel model is used. Wh...

In this paper, the use of Independent Component Analysis (ICA) neural networks for multiuser detection in multipath DS-CDMA communication systems operating in convolutive channels is examined, in both synchronous and asynchronous cases. To take advantage of known parameters, the ICA detector system was initialized by a detector that uses a subspace...

Independent component analysis (ICA) is a self-organizing learning algorithm that minimizes the matual information (MI) between the outputs of a neural network. The inputs to the algorithm are mixtures of various sources and the outputs are obtained after minimizing the MI. Most such algorithms operate in batch-mode. We give an on-line learning alg...

The concept of Robustness Measure (RM) and Noise Measure (NM) is introduced. Theses measures are used as a tool to gauge the performance of a closed loop fuzzy system. A linguistic description of the Robustness Measure and Noise Measure is given. Both measures are used for fuzzy and deterministic plant models. The measures give the user an indicati...

In this paper a semi-blind LMMSE multiuser detector is given for use in multipath DS-CDMA communication systems. The detector uses a subspace-based method of estimating channel noise. Due to its computational simplicity, the detector is suitable for use in either the downlink or the uplink of a DS-CDMA system. This detector gives superior performan...

A new autonomous feedback neural network is presented. Compared to Hopfield's network it has higher storage density and resolution which greatly improves the utility of smaller networks. Arising from Hopfield's network, the new network incorporates Hebbian learning, neural variety, and cooperative specialization. It has a dynamic structure via a hi...

A lattice predictor is used for frequency estimation of a harmonic process in additive Gaussian noise. Methods based on second-order statistics can be used for frequency estimation. However, when the harmonic signal is corrupted by noise, they give biased frequency estimates. We propose a higher-order statistic based block algorithm that reduces th...

We use a new theorem about obtaining the fuzzy relation of a closed-loop feedback system given the fuzzy relations of the plant and the controller. Based on this theorem, a new design procedure of a fuzzy controller is proposed. To understand concepts, an example is used throughout the paper. Then, based on the fuzzy rules giving the desired behavi...

An important issue in control theory is stability. Even though fuzzy control has been successfully applied to many control problems, the issue of system stability has not been resolved. We show that stability criteria developed so far for fuzzy systems described by fuzzy relational equations have no practical application. To achieve a practical sta...

A self-learning fuzzy logic system is given for control of unknown multiple-input-multiple-output (MIMO) plants. Some nomenclature and several data types are introduced to develop a general formulation for controller activity. A random optimization algorithm is given to train the controller. A plant model is not required for training. Instead, trai...

This paper gives a method to distinguish between the transient and steady states of stochastic gradient algorithms under general error criteria using inequalities that exist among a set of output errors called adjacent errors. Based on these inequalities, a variable step size LMF algorithm is proposed which improves convergence and gives lower misa...

A fuzzy logic controller is given for general DC-DC converters. The controller rule base comes from knowledge of converter operation. By controlling the switching duty cycle, a DC-DC converter can track a time varying reference signal having bandwidth beyond 20 KHz. Thus, the converter can be used as a high efficiency linear power amplifier with al...

Comparing and sorting are common functions in natural and artificial systems. Many known algorithms that sort m numbers require time from O(m²) to O(m). Algorithms to find the greatest number have been realised in neural networks and discrete time systems. Presented in the paper is a new circuit, the MAXOR, which incorporates a continuou...

A self-learning Neural-net-based Fuzzy logic System (NFS) is designed to determine the gains of a PID controller. The controller operates in a closed-loop system. The NFS receives the error, error integral and error derivative signals, and by fuzzy inference it adjusts the controller gains. As a result, these gains vary with time to achieve good pe...

Some modeling errors of the RLS algorithm are defined. Inequalities among the variances of these errors are obtained. These inequalities show how the RLS algorithm behaves as it tracks process parameters. By simulation it is shown that virtually all algorithms like the RLS algorithm exhibit the same error behavior

A self-learning fuzzy logic system is given for control of unknown multiple-input-multiple-output (MIMO) plants. A concise formulation of fuzzy controllers for MIMO plants is presented. Through new terminology and data types, relations among the crisp input vector, the fuzzy basis set for all linguistic input variables, the cardinality vector of fu...

Using the fuzzy relational matrix model of a process and the fuzzy relational matrix of a controller, a new method for obtaining the fuzzy relational matrix of a closed-loop system with an external input is given. The presented method has the advantage that it produces a closed-loop system minimum-order fuzzy relation matrix. The included example s...

New errors are introduced. We call these errors latent errors and we investigate the latent errors in the Backpropagation (BP) algorithm. We show that the mean square latent error varies according to the correlation of the input vector sequence. With the latent error squared, we also obtain a set of weights that gives the least mean error squared f...

Impedance cardiography (ICG) is a novel noninvasive technique for measuring stroke volume (SV) on the basis of impedance changes in the thorax to applied electrical alternating current. ICG has not been broadly accepted for clinical use mainly because the most widely used formulas for SV by Kubicek and Sramek fail to reliably determine absolute val...

This paper gives a method for differentiating between the transient and steady states in the LMS algorithm using inequalities among a set of output errors. Based on these inequalities, it also gives an algorithm for automatic step size adjustment to both improve the convergence rate and reduce steady-state parameter estimation errors

This paper gives a method for distinguishing the states of the two dimensional LMS algorithm as it enhances an image in an area having high contrast variations or in an area having low contrast variations. This capability is used to automatically adjust the algorithm step size to improve image enhancement as the degree of contrast variation changes...

The authors give the results of software simulation of Hebbian (D. O. Hebb, 1949) associative learning. Ontogenesis in feedback neural networks similar to those devised by Hopfield implies an initial structure and a plan for associative learning with growth. Experimental results are given to show that the advantages of ontogenetic neural networks c...

Some new errors pertaining to the operation of the Kalman filter are defined, and expressions for the ensemble variances of these errors are obtained. Then, some inequalities among these variances are given. While instantaneous state estimation errors are not available during an application of the Kalman filter, instantaneous values for these new e...

A regular iterative algorithm (RIA) to extract all trees of a linear graph is presented. The algorith is developed from a sequential algorithm that operates on the incidence matrix of a graph. This RIA can be used to design a processor array that can find trees of a graph at a rate that is independent of the number of graph edges. The RIA is the ba...

This paper presents a technique for microcomputerbased real-time control of a three-axis pantograph robot. The dynamic model of a pantograph type manipulator, which includes both the kinematic and kinetic equations of motion. is first established by applying Lagrange's method. In order to improve the computational efficiency, the nonlinear and coup...

A television ophthalmoscope (TVO) developed at the University of Illinois at Chicago combines low-light-level television camera and digital image processor to acquire and analyze images of the retina and chorold, one of the few areas of the body where the circulatory system can be observed in detail without surgery. So Far the TVO has been used in...

Colored Petri nets are used to model robot activity. A test is given such that erroneous steps in a plan of activity for taking a robot from an initial state to a goal state can be detected.

Critical heat flux (CHF) experiments were performed in a high pressure, forced convection, boiling water facility employing flowing sodium as the heating medium. Water pressure ranged from 7.0 to 15.3 MPa, and the water mass flux ranged from 0.72 to 3.2 Mg/m2s. Measurements were made of temperature fluctuations in the test section tube wall, adjace...

An amplitude modulated stereophonic system, which is compatible with conventional monophonic AM systems, is presented in this paper. First, conditions on the envelope and phase function for the transmitted signal are derived. Then, a compatible quadrature AM(compatible QUAM) system is proposed for the transmission and reception of stereophonic prog...

A programmable digital signal processing system is proposed in this paper. The system utilizes a 16 bit microprocessor for user interaction and a bit slice microprocessor for executing the filtering algorithm.

Thermal fluctuations were measured in the tube wall in the transition boiling zone of a full-scale LMFBR sodium-heated steam generator tube. The tube had an inside diameter=10 mm, wall thickness=2.90 mm, heated length=13.1 m, and material=2 1/4 Cr-1 Mo steel. Water flowed vertically upwards inside the straight tube, and sodium flowed counter-curren...

Information-theoretic concepts are used to derive some fundamental principles for the general estimation problem. With these basic principles, a minimal-error entropy estimator for linear systems disturbed by Gaussian random processes is easily derived, which is identical to the Kalman filter. Under non-Gaussian disturbances it is shown that the Ka...

A microprocessor based digital signal processing system is presented in this paper. The software developed for this system enables the user to easily specify any kind of a digital filter for realtime operation. As demonstrated by a sample hardware design and implementation, low-cost dedicated applications are now feasible.

This paper presents a simple formula for evaluating an often encountered integral when calculating energy related quantities in linear systems. Examples are included.

Information-theoretic concepts are utilized to develop a procedure for identifying a parameter of a stochastic linear discrete time dynamic scalar system based on noisy linear measurements of the system's state. After various simplifying approximations, the derived error entropy identification algorithm reduces to an on-line adaptive identification...

Results in estimation theory are applied to the problem of removing aberrations caused by imaging systems. Recursive models for the object image brightness function and the image sensor performance are developed. For the processing of NxN pixel images, known techniques require the formulation of an N2 order image degradation model to fully incorpor...

A design procedure for the measurement process is proposed to decrease the computational burden of state estimation in linear discrete-time systems. System order reduction is involved, which is achieved by a derived transformation, yielding an alternative system and measurement process representation that includes time delays in both the system and...

Error entropy estimation principles are used to analyze the smoothing problem for linear discrete time systems. Using information-theoretic concepts, a smoothing rate upper bound formula is developed which is considerably simpler to use than determining smoothing effectiveness by the optimal mean-square-error smoothing algorithm.

Information-theoretic concepts are developed and employed to obtain conditions for a minimax error entropy stochastic approximation algorithm to estimate the state of a non-linear discrete time system baaed on noisy linear measurements of the state. Two recursive suboptimal error entropy estimation procedures are presented along with an upper bound...

Algorithms for obtaining sub-optimal filtering, fixed-point smoothing, and fixed-lag smoothing estimates of the state of a non-linear system given noisy discrete time measurements are presented. The filtering problem involves obtaining estimates of the states x(kT) and x((k −1)T), and the smoothing algorithms generate an estimate of the state x((k...

A simple computer algorithm along with its Fortran programme is presented for extracting all trees or directed trees of ft linear graph directly from the incidence matrix. The method is based on the successive upper triangularization of the reduced incidence matrix to search out. non-singular majors and therefore identifying nil (directed) trees. P...

For discrete linear stochastic systems, a fixed-point smoothing algorithm is given to obtain optimal estimates of the state of the system at time k = i ( i fixed) when noisy linear measurements of the state are not available until the time k = j(j > i) . An example is included to illustrate smoothing degradation as ( j - i ) increases.

The application of communication technology may be the fundamental component in the development and implementation of urban universities in the future. An alternative to the present urban university is the total integration of communication technology into the modes of delivering university services. A model of this alternative is essentially an in...

A procedure is presented for reducing the on-line computing time and storage requirements when estimating the state of a class of linear-discrete systems.

First Page of the Article

An algorithm is presented for optimal linear fixed-point and fixed-lag smoothing in non-stationary linear discrete systems with multiple time delays. Relations derived previously in the problem of filtering are used directly to obtain the fixed-point and fixed-lag smoothing filters. The smoothing error covariance matrix is obtained via a recursive...

We give a near real-time algorithm for the blind separation of sources from mixtures of delayed sources. Many successful algorithms have been proposed for blind separation of instantaneous mixtures. For delayed mixtures only a few algorithms have been reported, and they assume only cross delays between mixed sources. Moreover, the weights and cross...

Thesis (Ph. D.)--Illinois Institute of Technology, 1969.

The method of orthogonal projection is used to derive the equations for optimally estimating the state of a nonstationary linear discrete system with multiple time delays. A Kalman-type filter is developed, along with the necessary recursive error and cross error covariance matrix equations. A numerical example is included.