Showing papers by "Tampere University of Technology published in 1980"

Aids for the handicapped based on "Synte 2" speech synthesizer

Abstract: SYNTE 2 is a low-cost, high-quality, text-to-speech synthesizer designed for Finnish but applicable also to other languages if "phoneme writing" is used. After its first presentation in 1977 it has been adapted to many communication aids for the handicapped. The first application was a portable speaking machine with unlimited vocabulary for the speech impared. This paper describes the present applications of SYNTE 2, including the speaking machine, a talking data terminal for blind computer programmers, a system for automatic production of spoken information for the blind, etc.

Two ferromagnetic methods for the evaluation of the fatigue limit in polycrystalline iron

Abstract: The influence of stress cycling with constant applied stress amplitudes on the formation of noise signals in the normal and in the mechanical Barkhausen mode has been studied in a polycrystalline iron of a commercial purity. It has been shown that the median pulse value of the noise signals in both modes is a variable sensitive enough to reveal whether the applied stress amplitude is below or above the fatigue limit. This offers a new and convenient way to measure fatigue strength non-destructively In the mechanical Barkhausen mode, the formation of the noise signals also directly reveals how the applied stress amplitude is correlated with the fatigue limit.

Robust multivariable PI-controller for distributed parameter systems

Abstract: A Robust multivariable PI-controller for distributed parameter systems is introduced The presented theory generalizes Davisons finite-dimensional robust control theory to infinite-dimensional systems

Distribution of m.e.g. detector sensitivity: an application of reciprocity

Abstract: THE development of superconducting detectors for detecting low magnetic fields (ZIMMERMAN and FREBEaICK, 1971) has offered new complementary techniques for investigating the bioelectric signals of the human body. One of these techniques, magnetoencephalography (re.e.g.), provides a new method for diagnosing the bioelectric activity of the brain. The magnetoencephalogram was first detected by COHEN (1968). The purpose of this paper is to investigate the theory of the detection of the electric activity of the brain by magnetoencephalography and to compare it with the electroencephalogram (e.e.g.), This is made from the lead field theory viewpoint.

Fast multiprocessor realizations of digital filters

Abstract: This paper presents a method for finding efficient multiprocessor realizations of digital filters. It provides a framework for studying the tradeoffs between the sampling rate and the number of arithmetic units or processors. A simple method for determining the minimal sampling period as a function of addition and multiplication times is introduced. Also the effect of delays in data transfers on the sampling period can be analyzed for different hard-ware configurations. Some examples are presented to show the use of the method in obtaining efficient multiprocessor realizations.

A self-tuning predictor for a class of multivariable stochastic processes

Abstract: This paper concerns the prediction of multivariable stochastic time series. An algorithm for a self-tuning predictor is constructed and some of its properties are discussed. Possible modifications of the algorithm for practical applications are also presented. A simulated example further illustrates the behaviour of the predictor.

Tuning of a multivariable PID-controller for unknown systems

Abstract: Tuning of a multivariable PID-controller is treated, when the system is assumed to be unknown but linear time-invariant and stable. Discussion is limited to the case, when both the class of reference signals and disturbances consists of step signals.

Determination of functional residual capacity with 133-xenon radiospirometry. Comparison with body plethysmography and helium spirometry. Effect of body position

Abstract: This study was undertaken to estimate the accuracy of 133-xenon radiospirometry for determination of FRC in healthy subjects. Forty healthy volunteers, both smokers and non-smokers, were examined. The FRC of each subject was concurrently determined with radiospirometric, He-dilution in closed circuit, and body plethysmographic methods. The radiospirometric and He-dilution measurements were done in supine and in sitting positions, the body plethysmography on sitting subjects, only. The mean FRC measured by radiospirometry (FRCRS) was 0.721 larger than that measured by helium spirometry (FRCHe) in sitting position (P<0.01). In supine position the FRCRS was 0.65 I larger than the FRCHe (p<0.01). The body plethysmography gave FRC (TGV) 0.35 I larger than the FRCHe sitting (P<0.01). The FRCHe and the FRCR≥ in the sitting position were 0.48 and 0.55 I larger than in the supine position (P<0.01), respectively. Trapped air correlated significantly (P<0.01) with the difference FRCRS-FRCHe, when sitting. The result...

Equal ripple amplitude and group delay digital filters

Abstract: In this paper we discuss a new class of hybrid IIR/ FIR digital filters. These filters present equiripple behaviour both in the magnitude and group delay responses. The all-pole IIR component is synthesized so that its group delay exhibits an equiripple variation in the passband whereas the linear phase FIR component is used to obtain the desired equiripple nature in the amplitude response both in the passband and stopbands. The filter types handled are lowpass, bandpass and highpass. By suitably optimizing the ripple in the group delay and the order of the IIR component we obtain filters requiring significantly fewer multipliers than equivalent FIR and group delay equalized elliptic designs when the pass-band is narrow (of order .1π or smaller) and a rather sharp cutoff is required. Examples illustrating this feature are presented in the paper.

Optimum recursive digital filters with zeros on the unit circle

Abstract: In this paper we present an efficient algorithm for designing recursive digital filters with optimum magnitudes in the Chebychev sense, all zeros on the unit circle, and different order numerators and denominators. This algorithm takes advantage of the well-known relations between the poles and zeros of analog filters having an equiripple amplitude response either in the passband or stopband. The algorithm requires thus only one approximation interval. This makes it more efficient than the algorithm of Martinez and Parks [1],which works separately with the numerator and denominator. The number of multiplications in the resulting filters is discussed and the optimal orders for numerator and denominator polynomials are considered. A simple explanation for the effect of an extra ripple [1] and for the minimum attainable passband ripple is given.

On the discrete-time regulator problem in infinite-dimensional spaces

Abstract: The linear, discrete-time regulator problem is considered in infinite-dimensional spaces without posing in advance any positivity conditions on quadratic criterion. The convergence of the finite-time optimum solution is studied, when time increases to infinity with a stable, stabilizable, and detectable system.

Microprocessor-based four-channel electronystagmography system

Abstract: TH~ microprocessor-based instrument, which is described here, is intended for the online computation of eye movement responses produced in vestibular function testing. In this connection the matter of interest is nystagmus, which is involuntary to-and-fro movement of the eyes. In recording eye movements, an electrical method, electrooculography (e.o.g.), is often used. This is also called electronystagmography (e.n.g.), when specifically used for the recording of nystagmus. Nystagmograms are usually analysed manually. Computer-based methods have also been developed (HERBERTS et al., 1968; TOLE and YOUNG, 1971; KTONAS et al., 1975; A~LUM et al., 1975) for this task, but the high cost has limited their number. Modern 1.s.i. (large-scale integration) technology, however, is now offering a chance to construct highly intelligent and flexible devices at a relatively low cost. As evidence of this, a microprocessorbased instrument for the analysis of nystagmus was presented two years ago (MICH~ELS and TOLE, 1977). In our project a microprocessor-based e.n.g, analyser is also under test and development. It is mainly intended to perform numerical analyses of e.n.g, recordings in conjunction with caloric tests. Although the movements of the eyes are usually conjugate, in some instances (NACLE and ANDERSON, 1972) disconjugate movements also occur in normal patients. A later work by KIMM and MACLEAN (1975) reports disconjugate eye movements in conjunction with central nervous system disorders, thus arguing in favour of