Showing papers by "University of Warsaw published in 1987"
TL;DR: The compact matrix pseudogroup as mentioned in this paper is a non-commutative compact space endowed with a group structure, and the existence and uniqueness of the Haar measure is proved and orthonormality relations for matrix elements of irreducible representations are derived.
Abstract: The compact matrix pseudogroup is a non-commutative compact space endowed with a group structure. The precise definition is given and a number of examples is presented. Among them we have compact group of matrices, duals of discrete groups and twisted (deformed)SU(N) groups. The representation theory is developed. It turns out that the tensor product of representations depends essentially on their order. The existence and the uniqueness of the Haar measure is proved and the orthonormality relations for matrix elements of irreducible representations are derived. The form of these relations differs from that in the group case. This is due to the fact that the Haar measure on pseudogroups is not central in general. The corresponding modular properties are discussed. The Haar measures on the twistedSU(2) group and on the finite matrix pseudogroup are found.
1,902 citations
TL;DR: In this paper, a C*-algebre A engendree par deux elements α et γ satisfaisant une relation de commutation simple dependante de ν is presented.
Abstract: Pour un nombre ν de l'intervalle [−1, 1], on introduit et on etudie une C*-algebre A engendree par deux elements α et γ satisfaisant une relation de commutation simple dependante de ν
972 citations
TL;DR: In this article, single-particle energies and wave functions of an axially deformed Woods-Saxon potential are computed, and the nuclear shape is defined in terms of an expansion into sphericalharmonics.
491 citations
TL;DR: In this article, the basic equations governing the amplifier operation were derived analytically using Laplace-transform techniques and assuming a constant current through the dc-fed choke, and the results can be used for designing Class E stages at any Q and switch duty cycle D.
Abstract: Previous analytical descriptions of a Class E high-efficiency switching-mode tuned power amplifier have been based on the assumption of an infinite Q or the minimum possible value of Q . This paper presents an exact analysis of the Class E amplifier at any Q and any switch duty cycle D , along with experimental results. The basic equations governing the amplifier operation are derived analytically using Laplace-transform techniques and assuming a constant current through the dc-fed choke. The following performance parameters are determined for optimum operation: the current and voltage waveforms, the peak collector current and collector-emitter voltage, the output power, the power-output capability, the load-network component values, and the spectrum of the output voltage. It is shown that all parameters of the amplifier are functions of Q . Therefore, the high- Q assumption used in previous analyses leads to considerable errors. For example, for Q at D = 0.5 , some errors are up to 60 percent. The results can be used for designing Class E stages at any Q and switch duty cycle D . The measured performance shows excellent agreement with the design calculations. The collector efficiency was over 96 percent at 2 MHz for all tested values of Q from 0.1 to 10.
388 citations
TL;DR: Results of a multidimensional search for nuclear superdeformed configurations are presented and a relatively strong dependence of the ''super'' elongation on the particle number is shown to be a cyclic function of the particles number.
Abstract: Results of a multidimensional (${\ensuremath{\beta}}_{2}$, \ensuremath{\gamma}, ${\ensuremath{\beta}}_{4}$, \ensuremath{\omega}, Z, and N) search for nuclear superdeformed configurations are presented. Calculations based on a realistic deformed average field give a relatively strong dependence of the ``super'' elongation on the particle number. This dependence is shown to be a cyclic function of the particle number. It originates from the pseudospin and pseudo-SU(3) symmetries which are obeyed approximately in a realistic average field.
260 citations
TL;DR: In this article, a top undergoing constant precession around a magnetic field and suffering a periodic sequence of impulsive nonlinear kicks is discussed, where the quantum dynamics take place in a finite dimensional Hilbert space.
Abstract: We discuss a top undergoing constant precession around a magnetic field and suffering a periodic sequence of impulsive nonlinear kicks. The squared angular momentum being a constant of the motion the quantum dynamics takes place in a finite dimensional Hilbert space. We find a distinction between regular and irregular behavior for times exceeding the quantum mechanical quasiperiod at which classical behavior, whether chaotic or regular, has died out in quantum means. The degree of level repulsion depends on whether or not the top is endowed with a generalized time reversal invariance.
254 citations
TL;DR: In this article, the authors considered the problem of robust stabilization of a linear time-invariant system subject to variations of a real parameter vector and proposed a design procedure to robustify a given stabilizing controller.
Abstract: This paper considers the problem of robust stabilization of a linear time-invariant system subject to variations of a real parameter vector. For a given controller the radius of the largest stability hypersphere in this parameter space is calculated. This radius is a measure of the stability margin of the closed-loop system. The results developed are applicable to all systems where the closed-loop characteristic polynomial coefficients are linear functions of the parameters of interest. In particular, this always occurs for single-input (multioutput) or single-output (multiinput) systems where the transfer function coefficients are linear or affine functions of the parameters. Many problems with transfer function coefficients which are nonlinear functions of physical parameters can be cast into this mathematical framework by suitable weighting and redefinition of functions of physical parameters as new parameters. The largest stability hyperellipsoid for the case of weighted perturbations and a stability polytope in parameter space are also determined. Based on these calculations a design procedure is proposed to robustify a given stabilizing controller. This algorithm iteratively enlarges the stability hypersphere or hyperellipsoid in parameter space and can be used to design a controller Io stabilize a plant subject to given ranges of parameter excursions. These results are illustrated by an example.
190 citations
TL;DR: In this article, the Hartree-Fock (HF) equations for the (He)2 system are solved using a suitable exchange perturbation technique, and the HF interaction energy is then obtained directly from a rapidly convergent iteration procedure.
Abstract: The Hartree-Fock (HF) equations for the (He)2 system are solved using a suitable exchange perturbation technique. The HF interaction energy is then obtained directly from a rapidly convergent iteration procedure. The method remains convergent for short interatomic distances, where the interaction energy surpasses the energy of intraatomic excitations. The fast convergence of the method is a result of the proper treatment of the exchange-deformation effects. In the region of the van der Waals minimum, these effects account for 50% of the HF deformation energy.
154 citations
TL;DR: In this paper, the authors derive from the equations of the nonlinear thermoelasticity a certain class of homogenized models of periodic composite materials, based on the methods of nonstandard analysis.
121 citations
TL;DR: In this paper, the maximum charged particle density per given rapidity interval is found to rise linearly with charged particle multiplicity, independent of beam particle type and practically independent of energy between 22 and 900 GeV.
111 citations
TL;DR: In this article, the transverse energy in average central collisions is ≈ 75 GeV for the interval 2.2⩽ y ⩽3.8 and a 16-fold convolution of the inelastic p+Au transversal energy spectrum, also measured at 200 GeV, reproduces the mean E T of 16 O+Pb.
TL;DR: In this paper, it was shown that any torsion unit of the integral group ring Z G is rationally conjugate to a trivial unit if G = A ⋊ X with both A and X abelian, | Xz. sfnc ; p for every prime p dividing | A | provided either | X | is prime or A ic cyclic.
TL;DR: The place of temperament in personality research has been broadly discussed taking into account different understandings of both concepts "temperament and personality" as discussed by the authors, and it has been regarded as a predictor of personality.
Abstract: The place of temperament in personality research has been broadly discussed taking into account different understandings of both concepts ‐ temperament and personality. Temperament may be regarded ...
TL;DR: In this article, a polynuclear ruthenium oxide/cyanoruthenate films on carbon substrates were grown by cycling the potential between 0.5 and 1.0 V (vs SCE) for 5-90 min in fresh 2 m M RuCl 3 ·3 H 2 O, 2m M K 4 Ru(CN) 6 ·3H 2 O and 0. 5 M KCl solution at pH 2.
TL;DR: Critical analysis of such factors as food abundance, the size and number of shared prey, and diet breadth showed that all significant overlaps were ecologically unimportant i.e. there was only weak competition for food.
Abstract: Food resources in the environment and in the diets of small fish inhabiting two water bodies in a tropical savanna were studied during both wet and dry seasons. During the wet season (high water, abundant food) most fish species in both habitats fed predominantly on vegetation-dwelling invertebrates. Most fish species switched to alternative foods (algae and detritus) following the drastic decline in invertebrate food available towards the end of the dry season. In one habitat, this change in diet was accompanied by an increase in the volume of food intake. In the second habitat, only two larger species foraged intensively, while smaller species showed low food intake or almost ceased feeding. These differences may be explained by the high risk of predation for small fish in the second habitat. Dietary overlaps among fish species were high at the end of the dry season and moderate in the wet season. However, critical analysis of such factors as food abundance, the size and number of shared prey, and diet breadth showed that all significant overlaps were ecologically unimportant i.e. there was only weak competition for food.
TL;DR: Lead migrating through the tissues of Allium cepa L. was found to encounter at least three barriers to penetration, which were barriers to apoplastic and symplastic transport, and the cells of the deepest ground meristematic tissue layers seemed to act as a barrier, which keeps lead away from the procambium.
Abstract: Lead migrating through the tissues of Allium cepa L. was found, by electron microscopy, autoradiography and other methods, to encounter at least three barriers to penetration. The layers of protoderm and hypodermic meristematic cells in the root meristematic zone and the layer of endodermis in the mature root zone were barriers to apoplastic transport. The central zone was a barrier to apoplastic and symplastic transport. It comprises the quiescent centre in the root meristem and the central part of the root cap. The cells of the deepest ground meristematic tissue layers seemed to act as a barrier, which keeps lead away from the procambium. Lead accumulated in roots but it was not uniformly distributed between their various tissues. The largest amount of lead accumulated both in ground meristematic and cortex tissues.
TL;DR: In this paper, the convergence properties of the Moller-Plesset dispersion energy with respect to saturation of polarization basis set have been investigated, by means of the partial wave expansion through “i” terms, for the He dimer.
TL;DR: The circular polarization of GaAs/InP system is calculated for the first time taking into account the true nonparabolic valence-band structure and high positive polarization for the transition n=1 heavy-hole\char21{}to-to-conduction-band transition is found.
Abstract: We calculate for the first time the circular polarization of GaAs/${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Al}}_{\mathrm{x}}$As quantum-well photoluminescence taking into account the true nonparabolic valence-band structure. Versus the excitation energy, we find high positive polarization for the transition n=1 heavy-hole\char21{}to\char21{}conduction-band transition and negative polarization at the onset of n=1 light-hole\char21{}to\char21{}conduction-band transition in qualitative agreement with experiments. We also study the ${\mathrm{Ga}}_{\mathrm{y}}$${\mathrm{In}}_{1\mathrm{\ensuremath{-}}\mathrm{y}}$As/InP system and predict no negative polarization in this case.
TL;DR: In this paper, it was shown that the memory function of concentration fluctuations M(k, t) derived from the generalized Smoluchowski equation is not a one-particle irreducible quantity.
Abstract: It is shown that the memory function of concentration fluctuations M(k, t), derived from the generalized Smoluchowski equation, is not a one-particle irreducible quantity A new function M(k, t), which is one-particle irreducible, is derived and the relation between both functions is established The irreducible memory function M(k, t) can be interpreted as a dynamic viscosity In contrast to earlier statements there is no discrepancy in the results, which are obtained from phase space approach (Fokker-Planck equation) and those obtained from the Smoluchowski equation
TL;DR: In this article, total inelastic pp cross-sections are reconstructed for laboratory kinetic energies ranging from 0.3 to 400 GeV by fitting together the sum of total cross-section for exclusive channels.
Abstract: Total inelastic pp cross-sections are reconstructed for laboratory kinetic energies ranging from 0.3 to 400 GeV. They are obtained by fitting together the sum of total cross-sections for exclusive inelastic channels, the sum of topological cross-sections and the results for independent « direct » measurements. The inelastic np cross-sections are reconstructed in the energy range below 4.2 GeV using the sum of individual exclusive channels and the direct measurements. The cross-sections are fitted by series of generalized Laguerre polynomials insuring a correct threshold behaviour. The results of the fits are presented in tables and in figures, where they are compared with existing data. The obtained total cross-section energy dependences made it possible to determine the total cross-section for the isospin I = 0 state and to test isospin invariance predictions for individual types of reaction. The agreement of the data with the predictions is surprisingly poor in the case of NN => NN03C0 reactions. J. Physique 48 (1987) 1901-1924 NOVEMBRE 1987, Classification Physics Abstracts 13.75
TL;DR: In this article, the truncated Hilbert expansion including the initial layer terms is considered and the existence of a strong solution of the Boltzmann equation is obtained for initial data close enough to a local Maxwellian.
Abstract: The truncated Hilbert expansion including the initial layer terms is considered. This enables us to replace the singulary perturbed Boltzmann equation by a weakly nonlinear equation. In this way the existence of a strong solution of the Boltzmann equation is obtained for initial data close enough to a local Maxwellian. The solution exists in the physically significant time interval on which smooth solutions to the Euler equations exist.
TL;DR: In this paper, a new definition for a cooperativity parameter is proposed, based on the two-body, non-neighbour interaction energy, plus three- and four-body contributions, including one-body deformation terms in relation to the total interaction energy of the water tetramer.
Abstract: The additional energy stabilization due to cooperative effects was calculated in extended hydrogen bonded systems OH OH OH with unidirectional (homodromic) orientation of the OH groups. Ab initio restricted Hartree Fock, MP2 and MP3 calculations with geometry optimization and BSSE correction have been performed using the GAUSSIAN 83 program package for the ground states of the linear water dimer with Cs symmetry and the cyclic water tetramer with S4 symmetry. The latter represents the smallest possible, experimentally observed cooperative structure. A new definition for a cooperativity parameter is proposed. The definition is based on the two-body, non-neighbour interaction energy, plus three- and four-body contributions, including one-body deformation terms in relation to the total interaction energy of the water tetramer. The advantage of this definition is its independence of the reference system, which is necessary in complicated molecular systems with an undefined number of hydrogen bonds, such as disordered or flip-flop systems. According to this definition the energy gain based on cooperativity in the S4 water tetramer is 29% with the MP3/6-31G** approximation, (30% with HF/4-31G* and 46% with HF/3-21G). The largest contribution of 18% is due to the three-body term on the MP3/6-31G** level, followed by the two-body, non-neighbour term with 11%. The four-body term and the deformation term are in the order of 1% and cancel each other because they have opposite sign.
TL;DR: In this paper, a study of the distribution of the azimuthal angle ϕ of charged hadrons in deep inelastic μ−p scattering is presented, and the dependence of the moments of this distribution on the Feynmanx variable and the momentum transverse to the virtual photon is analyzed.
Abstract: A study of the distribution of the azimuthal angle ϕ of charged hadrons in deep inelastic μ−p scattering is presented. The dependence of the moments of this distribution on the Feynmanx variable and the momentum transverse to the virtual photon indicates that non-zero moments arise mainly from the effects of the intrinsicK
T
of the struck quark with >≳(0.44 GeV)2, and to a lesser extent from QCD processes. No significant variation withQ
2 orW
2 is observed.
TL;DR: In this paper, the physical meaning of ΔG°ad is discussed in terms of choice of standard states, form of the isotherm equation, true adsorption equilibrium reaction and contributions from interactions in the solution bulk.
TL;DR: A review of the literature shows that there is a growing interest in temperament that has developed in parallel to studies of emotion as discussed by the authors, and the authors adopts a historical perspective on the relationship between temperament and emotion and shows the place of emotion in current research on temperament.
01 Oct 1987
TL;DR: A new technique for designing self-testing VLSI circuits, referred to as Circular Self-Test Path, is presented, which is a feedback shift register with data compaction capability with a low silicon area overhead.
Abstract: A new technique for designing self-testing VLSI circuits, referred to as Circular Self-Test Path, is presented. The Circular Self-Test Path is a feedback shift register (output of the last flip-flop is supplied to the first flip-flop) with a data compaction capability. A distinguishing attribute of self-testing chips designed using this technique is a low silicon area overhead, slightly exceeding that of scan path designs. A theoretical analysis and comprehensive simulation experiments are performed to demonstrate that the effectiveness of test pattern generation for the circular self-test path is comparable to that of an ideal pseudorandom test generator.
University of Turin1, Uppsala University2, University of Warsaw3, CERN4, Lancaster University5, RWTH Aachen University6, University of Paris7, University of Kiel8, Laboratoire d'Annecy-le-Vieux de physique des particules9, University of Liverpool10, University of Sheffield11, Max Planck Society12, University of Freiburg13, University of Hamburg14, University of Oxford15
TL;DR: In this paper, the multiplicity distributions of charged hadrons produced in the deep inelastic muon-proton scattering at 280 GeV are analyzed in various rapidity intervals, as a function of the total hadronic center of mass energy ranging from 4-20 GeV.
Abstract: The multiplicity distributions of charged hadrons produced in the deep inelastic muon-proton scattering at 280 GeV are analysed in various rapidity intervals, as a function of the total hadronic centre of mass energy W ranging from 4–20 GeV. Multiplicity distributions for the backward and forward hemispheres are also analysed separately. The data can be well parameterized by binomial distributions, extending their range of applicability to the case of lepton-proton scattering. The energy and the rapidity dependence of the parameters is presented and a smooth transition from the negative binomial distribution via Poissonian to the ordinary binomial is observed.
TL;DR: In this paper, the problems of modeling multilayered periodic composites have been dealt with and the proposed models take into account certain micromorphic effects resulting from the periodic structure of the body.
TL;DR: It is suggested that even under strong fish predation pressure there is no reason to migrate when seston is relatively homogenously distributed throughout the water column.
Abstract: Neither Daphnia hyalina, Daphnia cristata, nor Daphnia cucullata vertically migrated in Lake Mikolajskie and Lake Majcz. We suggest that even under strong fish predation pressure there is no reason to migrate when seston is relatively homogenously distributed throughout the water column.