Showing papers by "Tampere University of Technology published in 1981"
TL;DR: In this paper, the authors present a framework for computing the minimal sampling period of a given digital filter structure when the speed of arithmetic operations is given but the number of processing units is unlimited.
Abstract: This paper presents a framework for Fiding efficient multiprocessor realizations of digital filters. Based on simple graph-theoretic concepts, a method is derived for determining the minimal sampling period of a given digital filter structure when the speed of arithmetic operations is given but the number of processing units Is unlimited. It Is shown how realistic hardware implementations can be found and evaluated by using the timing diagram of this maximal rate realization as a starting point. The minimal sampling periods of several common digital filter structures are given in terms of addition and multiplication times.
305 citations
TL;DR: In this paper, the authors defined the transmission zeros as the limit points of the spectrum as the feedback gain increases to infinity, and a simple criterion which characterizes the transmission zero, different from the system operators spectrum, is found.
Abstract: The transmission zeros, for a class of distributed parameter systems, are defined as the limit points of the spectrum as the feedback gain increases to infinity. A simple criterion, which characterizes the transmission zeros, different from the system operators spectrum, is found. The case, when the transmission zeros belong to the spectrum, is also discussed. The presented theory is clarified with an example.
35 citations
TL;DR: In this article, measurements of small-angle neutron scattering were done on undeformed and cyclically deformed copper single crystals of the orientation 〈111〉 and of a thickness of 4mm.
28 citations
01 Dec 1981
TL;DR: In this paper, a multivariable discrete-time PI-controller, which uses interactions of the plant subject to step inputs, is discussed, where the plant is assumed to be unknown but linear time invariant and stable.
Abstract: Tuning of a multivariable discrete-time PI-controller, which uses interactions of the plant is discussed. Interactions are detected by observing the output of the plant subject to step inputs. The plant is assumed to be unknown but linear time-invariant and stable. The presented tuning method is an extension of the corresponding continuous-time method [1], [2].
27 citations
TL;DR: The Elias-bound in the Lee-metric is modified to improve the known bounds for the code parameters in some cases and the result is applied to perfect codes to obtain nonexistence theorems.
Abstract: The Elias-bound in the Lee-metric is modified to improve the known bounds for the code parameters in some cases. The result is applied to perfect codes to obtain nonexistence theorems. For large alphabets it is proved that n ⩾ (e + 2)2/2.1, if n denotes the block length of a perfect Lee-code correcting e errors and e ⩾ 285.
16 citations
16 citations
TL;DR: A feedforward controller is introduced for an important class of distributed parameter systems to regulate the outputs of the system in spite of some perturbations.
Abstract: A feedforward controller is introduced for an important class of distributed parameter systems. The purpose of the control is to regulate the outputs of the system in spite of some perturbations. The theory presented is clarified with an example.
14 citations
TL;DR: In this article, a simple solution procedure is presented to solve conjugated heat transfer composed of conduction in a fin and convection from it, and the heat transfer of an actual fin is compared with an ideal isothermal fin.
13 citations
TL;DR: In this article, an attempt is made to determine experimentally the asymmetry parameter β for electrons with various angular momenta from solid samples, which is somewhat more complicated than that for determining β from gaseous samples.
Abstract: An attempt is made in the present work to determine experimentally the asymmetry parameter β for electrons with various angular momenta from solid samples. This method is somewhat more complicated than that for determining β from gaseous samples. The β values obtained, for instance for Cu 2p, are β = 1.86 and 1.34 by using for A1 Kα and Mg Kα excitation radiations respectively. The corresponding theoretical values are β = 1.42 and 1.32. Examples are also given for the significance of the anisotropic angular distribution to quantitative surface analysis.
12 citations
TL;DR: The triangulation method of angle-resolved photoemission has been employed to determine individual electronic bands in an absolute way throughout an extended region of k-space comprising the Cu(001) mirror plane as discussed by the authors.
12 citations
TL;DR: It is shown that it is decidable of any endomorphisms σ, σ1…, ρm and any words P, P1….
TL;DR: An application of multivariable self-tuning controllers to a computer-controlled, laboratory-scaled concentration-flow process and a newly developed selftuning controller, derived by penalizing also the control signal in the cost are described.
TL;DR: It turns out that going through all propagating morphismsf and g, the family of maximal solutions obtained equals the famdy of complements of recursively enumerable languages after intersecting with regular languages and mapping with propagating Morphisms.
Abstract: After extending two word morphismsfand g to languages, an equationf(X) = g(X) can be written and ItS language soluUons investigated. An elementary characterization of the famdy of all solutions of the equation is ~ven, and it is used to mvesttgate the maximal solution which is the mum subject of this paper. It turns out that going through all propagating morphismsf and g, the family of maximal solutions obtained equals the famdy of complements of recurslvely enumerable languages after intersecting with regular languages and mapping with propagating morphisms. In the general case (of arbitrary morphismsf and g) the corresponding family is larger and includes the full-AFL closure of the family of complements of recursively enumerable languages.
01 Apr 1981
TL;DR: A new class of hybrid IIR/ FIR digital filters that present a maximally flat group delay in the given passband and an equiripple nature in the magnitude response both in the pass band and in the stopband are discussed.
Abstract: In this paper we discuss a new class of hybrid IIR/ FIR digital filters. These filters present a maximally flat group delay in the given passband and an equiripple nature in the magnitude response both in the passband and in the stopband(s). The all-pole IIR component is synthesized so that its group delay exhibits a maximally flat behaviour in the pass-band 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, band-pass and highpass. By suitably optimizing the maximum value 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 passband is narrow (of the order of .1π or smaller) and a rather sharp cutoff is required. The performance of these filters is, however, slightly worse that obtainable with corresponding filters having equiripple group delay [1]. Several comparisons between different filter types are presented.
TL;DR: In this article, the effect of changes in the quality of peat and disturbances in the feed can be observed only at the steam produced by the boiler, and it is shown that the fuel power correlates with the consumption of oxygen in the burning process.
TL;DR: In this article, the accuracy of the triangulation method can be improved by studying energy-coincident spectral features over an extended k -region in a plane of the Brillouin zone.
TL;DR: It is proved that a code can be perfect only if q |( n − 1 k ) , where n is the block length and k = [ 2e q ] .
TL;DR: A method was chosen where the values of the curves are programmed in a digital memory, from which they are converted into an analogue signal, using an 8-bit digital-to-analogue conversion, which permits easy change of the waveforms by just reprogramming the memory.
Abstract: THE accuracy of generally used line-approximation methods, based on analogue techniques (BLAZEK et al., 1975), is insufficient for scientific purposes and, in particular, synchronisation of the three different waveforms is very difficult when employing the analogue technique. After examining many different alternatives, a method was chosen where the values of the curves are programmed in a digital memory, from which they are converted into an analogue signal, using an 8-bit digital-to-analogue conversion. This method is stable and permits easy change of the waveforms by just reprogramming the memory. Hence the same equipment can be used to generate various kinds of waveforms by replacing the memory-circuit. In the current application, the heart-rate adjustment was limited to the range 60-100/min and the output intensity adjustment to 0-2.5V peak/peak. The equipment was designed to be battery-operated to obtain a floating potential signal source with a very small earth-capacitance and to make
TL;DR: A design method for on-plant tuning of multivariable PI-controllers for unknown systems is presented, assuming the plant is assumed to be linear, open-loop stable with input delays and subject to step disturbances.
01 May 1981
TL;DR: A synchronisation method for baseband data transmission in microprocessor networks is developed based on bit resynchronisation using counters, which provides a very efficient and fast correction response with relatively simple circuitry.
Abstract: A synchronisation method for baseband data transmission in microprocessor networks is developed. The method is applicable in systems using ADCCP-, HDLC- or SDLC-protocols and NRZI-code and point-to-point or loop-mode operation. The method is based on bit resynchronisation using counters. No phase-locked loops are used. This provides a very efficient and fast correction response with relatively simple circuitry. The performance of the system is analysed and tested in practice.
01 Jan 1981
TL;DR: In this paper, high-resolution measurements of L x-ray spectra in the region Z = 40 to 50 are few in the literature and therefore the knowledge of these spectra is quite limited.
Abstract: High-resolution measurements of L x-ray spectra in the region Z = 40 to 50 are few in the literature1,2,3,4,5 and therefore the knowledge of these spectra is quite limited. Krause et al6 have measured and studied theoretically L emission of zirconium. Chen et al have studied silver and based their interpretation on Parratt’s excellent measurement on Ag carried out fourty years ago2. Also for niobium Lα transitions have been investigated to some extent3,4. The aim of this work is to obtain a more detailed picture of L x-ray spectra of Nb and compare our results with theoretical data.
01 Jan 1981
TL;DR: In this paper, a closed-loop electrohydraulic fatigue testing system is presented, where the control for constant stress and constant plastic strain amplitude tests is provided by programming a minicomputer to evaluate the controlquantity in at least hundred points per a quarter-cycle, to compare it with the preset amplitude and to give command pulses to a function generator supplying the command signal to the closedloop servocontrolled testing system.
Abstract: A computer-controlled closed-loop electrohydraulic fatigue testing system is presented. Control for constant stress and constant plastic strain amplitude tests is provided by programming a minicomputer to evaluate the controlquantity in at least hundred points per a quarter-cycle, to compare it with the preset amplitude and to give command pulses to a function generator supplying the command signal to the closed-loop servocontrolled testing system. The software developed is described in detail, and the capabilities of the system are discussed. Finally, some further developing trends for applying the present system to random load fatigue testing are considered.