Showing papers by "Tampere University of Technology published in 1985"
TL;DR: In a prospective clinical study 44 patients with a displaced fracture of the ankle were randomly allocated to two groups; one was treated with conventional metallic implants and the other with the biodegradable implants.
296 citations
TL;DR: In this article, two simple truss examples, one static and one dynamic problem, are presented to show that this situation easily occurs in optimum structural design also, and the weighting method may fail in generating the Pareto optimal set of a multicriterion problem in non-convex cases.
Abstract: It is well known that the weighting method may fail in generating the Pareto optimal set of a multicriterion problem in non-convex cases. In this paper, two simple truss examples, one static and one dynamic problem, are presented to show that this situation easily occurs in optimum structural design also.
191 citations
TL;DR: The necessary and sufficient conditions for a digital filter transfer function to be implementable as a sum of two all-pass filters are derived directly in the z-plane as mentioned in this paper. But these conditions are not applicable to analog filters.
Abstract: The necessary and sufficient conditions are given for a digital filter transfer function to be implementable as a sum of two all-pass filters. The conditions are derived directly in the z -plane. The class of filters satisfying these conditions is shown to be wider than the class of filters obtained via the bilinear transformation from the corresponding conventional analog filters. An example shows that the given conditions enable us to design complementary filter pairs with different numerator and denominator orders directly using magnitude squared functions. These filters compare favorably with the corresponding classical filters.
90 citations
TL;DR: Three kind of convergences are defined on a space of fuzzy sets and some comments on the fixed point property are represented.
72 citations
TL;DR: In this article, the surface relief at the emerging persistent slip band is characterized by tongue-and ribbon-like intrusions and extrusions and the correlation of surface relief with the dislocation arrangement was determined.
67 citations
TL;DR: In this article, robust controllers are extended to the case of boundary and/or distributed control and the system operator is an infinitesimal generator of a strongly continuous exponentially stable semigroup.
55 citations
TL;DR: In this article, a study of surface morphology and crystal structure of the films shows that smooth surfaces with higher structural perfection than that of the substrate can be obtained under conditions optimal according to the ALE model.
36 citations
26 Apr 1985
TL;DR: It is shown that SMF's have essentially the same statistical properties and same type of root signals as the conventional MF's.
Abstract: In this paper we introduce a new generalized class of Median Filters (MF) which we call Smoothed Median Filters (SMF). The input signal x(n) is filtered with M linear phase FIR filters and the output of the SMF is the median of the outputs of the FIR filters. The statistical properties of the SMF's are analyzed for input signals with Gaussian, double exponential, and uniform density functions. It is shown that SMF's have essentially the same statistical properties and same type of root signals as the conventional MF's. SMF's preserve corner points and ramps and attenuate impulsive type noise components effectively. An interesting subclass of the SMF's requiring only two scaling multipliers and three data sorting operations irrespective of the filter length is introduced.
35 citations
TL;DR: A design method for on-plant tuning of multivariable PI-controllers for unknown systems is presented and an example is given to show the applicability of the controller proposed.
32 citations
TL;DR: In this article, the critical line from the ferromagnetic to the paramagnetic line is located, and critical exponents, in particular in the vicinity of the Lifshitz point, are estimated.
Abstract: The three-dimensional axial next-nearest-neighbor Ising (or ANNNI) model is studied using Monte Carlo techniques. Applying the coarse graining of distribution functions of the cell magnetization as well as standard analyses, the critical line from the ferromagnetic to the paramagnetic line is located, and critical exponents, in particular in the vicinity of the Lifshitz point, are estimated.
30 citations
TL;DR: In this paper, the corrosion behavior of various chemically vapour-deposited TiN coatings was determined by electrochemical polarization measurements in an aerated 0.01 N HCl aqueous solution.
TL;DR: In this article, the authors measured the d.c. electrical conductivity and breakdown voltages of r.f.-sputtered alumina layers 5 μm thick and found that the conductivity was of the order of 10 −15 ω -1 cm -1 at room temperature and of the course of 10 -11 ω −1 cm −1 at a temperature of 823 K in an argon atmosphere.
TL;DR: In this paper, the growth mode of Cu deposits on clean Pd(100) has been studied by means of LEED and AES and angular resolved ultraviolet photoemission spectroscopy.
TL;DR: In this paper, the cyclic stress-strain response of polycrystalline copper of two different grain sizes was studied in constant, incremental step and variable plastic strain amplitude fatigue tests.
TL;DR: In this article, various inorganic sulfur compounds and lignosulfonate were studied with respect to their effect on biogas production from synthetic wastewater simulating sulfite evaporator condensate.
26 Apr 1985
TL;DR: It is shown that all the filters in the bank can be implemented as linear combinations of the same low order allpass filters, and basic properties of the filters are discussed.
Abstract: The class of digital filter pairs satisfying two types of complementary properties simultaneously is reexamined. The pair is required to have complementary square magnitude characteristics with respect to a constant and transfer functions complementary with respect to an allpass function. This filter class, called doubly complementary filters is then extended to have M filters with complex outputs. Basic properties of the filters are discussed. It is shown that all the filters in the bank can be implemented as linear combinations of the same low order allpass filters. The individual filters can have different bandwidths and tolerances. The filter bank can also produce [M/2]+1 real outputs with allpass complementary responses that can be arbitrarily added up to form a variety of allpass complementary filters. The filters have low coefficient sensitivities in their passbands if the allpass sections are implemented with structures that are canonic with respect to the coefficients.
19 Jun 1985
TL;DR: In this article, the authors present the principles for modelling the grate boiler and propose a control system for supply and combustion parts of a grate boiler, which is based on a microprocessor-based data collection system.
Abstract: Grate boilers are widely used as active steam generation units in Finnish pulp and paper mills to control the steam network of the plant. The fuels burned on grates are typically bark and waste-wood. To ensure good stability and load following properties for grate boilers both drying and combustion processes must be well controlled. This presumes good instrumentation for the grate, special measurement and control systems for combustion power and good knowledge of the process behaviour. This paper presents the principles for modelling the grate boiler. Simulation model is developed on the basis of process experiments. The methods and devices, including a microprocessor based data collection system, for modelling and simulation are also handled. The paper further proposes a control system for supply and combustion parts of a grate boiler.
TL;DR: An area of intense activity in recent years involves the dynamics of ordering in a far-from-equilibrium system, where the growth law R (t) for the average size of the ordered domains, and the structure factor S(k, t), where k is the wave number and t is time.
Abstract: The development of order in the clock (${Z}_{N}$) model is studied following a quench from the disordered phase to a low-temperature unstable state below the ferromagnetic critical point. Growth laws for the average size of domains are obtained by computer simulation for N=3, 4, 8, 16, and 26 degenerate states. In disagreement with recent Monte Carlo work, no pinning by vortices is observed.
01 Dec 1985
TL;DR: A multivariable self-tuning PID (SPID) controller is introduced to robot manipulator control and it is shown that the structure is simple, eliminates interactions quite well, and is easy to implement.
Abstract: A multivariable self-tuning PID (SPID) controller is introduced to robot manipulator control. The control structure is simple, eliminates interactions quite well, and is easy to implement.
TL;DR: In this article, the kinetics of ordering in the Q-state Potts model on a square lattice are studied for quenches from a high-temperature, disordered state to low temperatures below the phase-transition point.
Abstract: The kinetics of ordering in the Q-state Potts model on a square lattice is studied for quenches from a high-temperature, disordered state to low temperatures below the phase-transition point. Growth laws for the average size of domains are obtained by Monte Carlo studies with Glauber dynamics for Q=3, 4, 6, and 8 for several low temperatures. In addition, the nonequilibrium structure factor is calculated for Q=8 and is shown to satisfy scaling. This study may be of some relevance to island growth in surface science, since the Potts model has been used to describe the adsorption of atoms on substrates.
26 Apr 1985
TL;DR: Examples demonstrate that by oversampling by a factor of 3, a third order analog filter is sufficient to construct an extremely linear phase highly selective anti-aliasing filter meeting the same amplitude specifications as a seventh order purely analog elliptic filter.
Abstract: A new approach is presented for the design of linear-phase anti-aliasing filters. These filters consist of an approximately linear phase analog filter cascaded with a linear phase nonrecursive digital decimator. The use of the decimation part enables us to use a higher sampling rate after the analog part. This increases the required transition bandwidth of the analog filter and, consequently, decreases the required filter order. The passband variation of the group delay response of the analog part is minimized subject to the given amplitude requirements. The optimization is done by an efficient iterative algorithm constructed using recent advances in constrained minimax optimization. As a decimator, we use a filter consisting of two parts, one working at the higher sampling rate and the other one at the final sampling rate. This filter requires significantly fewer multiplications per output sample than a conventional FIR decimator. Examples demonstrate that by oversampling by a factor of 3, a third order analog filter is sufficient to construct an extremely linear phase highly selective anti-aliasing filter meeting the same amplitude specifications as a seventh order purely analog elliptic filter.
TL;DR: In this article, the fatigue behavior of polycrystalline copper of two different grain sizes was studied using constant and randomly varying plastic strain amplitude tests, and the effect of different regimes in the ess-curves of large-grained samples (d˜ 2.0 mm) were found to be reflected also in measured fatigue lives in both test modes.
Abstract: Fatigue behavior of polycrystalline copper of two different grain sizes was studied using constant and randomly varying plastic strain amplitude tests. The different regimes in the ess-curves of large-grained samples (d˜ 2.0 mm) were found to be reflected also in the measured fatigue lives in both test modes. The variable amplitude fatigue lives of the small-grained samples (d˜ 0.03 mm) seemed to follow the Coffin–Manson linear law. The damage accumulation rate in variable amplitude tests was found to be lower than in the corresponding constant amplitude tests, e.g. when expressed as cumulative plastic strains to failure. The fatigue life predictions based on the Palmgren–Miner rule, rain-flow analysis and the constant amplitude life data measured in this work were also conservative.
TL;DR: The equivalence problem for multiplicity sets of regular languages is shown to be undecidable and the proposed solution to this problem is simple and elegant.
TL;DR: Moulage et proprietes mecaniques de polyethylene basse densite contenant des montures de contreplaques as discussed by the authors, a.k.a.
Abstract: Moulage et proprietes mecaniques de polyethylene basse densite contenant des montures de contreplaques
TL;DR: In this article, the costs of different types of aerobic, anaerobic and combined wastewater treatment systems are compared in a forest industry environment and the assumed BOD or COD-loads from typical forest industry processes form the basis of comparison.
TL;DR: In this article, a general class of digital filters with maximally flat passband magnitude, equiripple stopband magnitude and different order numerator and denominator was introduced, and an efficient iterative algorithm for the design of filters of the given type is presented, based on shaping the passband and stopband responses alternately until the difference between successive solutions is within given tolerance limits.
Abstract: This paper introduces a general class of digital filters with maximally flat passband magnitude, equiripple stopband magnitude, and different order numerator and denominator. the classical Chebyschev type II (inverse Chebyschev) filters having equal numerator and denominator orders are considered as special members of this filter class. the filter types to be considered are lowpass, highpass and bandpass. the proposed filter class consists both of filters having all the zeros on the unit circle and of filters having some zeros off the unit circle to contribute to the passband shaping.
An efficient iterative algorithm for the design of filters of the given type is presented. It is based on shaping the passband and stopband responses alternately until the difference between successive solutions is within given tolerance limits.
Several comparisons show that in wideband applications filters with numerator order higher than denominator order present considerable advantages over equivalent Chebyschev type II designs, in terms of multiplication rate and/or frequency selectivity. In narrowband applications, in turn, filters with higher denominator order are shown to be the most effective.
TL;DR: Both of the filters were found to decrease the equilibrium factor of daughters and increase the unattached fraction of decay products, and in a clean air they also decreased the activity of unattached daughters.
TL;DR: In this paper, the authors evaluated factors effecting sludge granulation and the relationship between sludge morphology and sludge activity, measured as a function of biogas production.