Filtyp
Stability of systems with hysteresis nonlinearities, parametric uncertainty and finite dimensional unmodelled dynamics is considered. Conditions for exponential decay of the signals in the system to an equilibrium position are given. The equilibrium is generally not unique. The stability condition is given in terms of a frequency domain inequality, which involves the transfer function of the nomin
It is shown that strict system equivalence in Rosenbrock's sense is equivalent to the existence of a certain bijective mapping between the sets of solutions to the differential equations describing the system. This leads to a simple proof of the fact that the equivalence classes under strict system equivalence are well defined, although the dimension of the system matrix is not uniquely defined. I
Two suboptimal dual controllers are applied to a first-order linear system. The first controller is developed by Sternby and the second by Tse. Bar-Shalom and Meier. The second controller is slightly modified to serve in a stationary situation. The only unknown parameter of the system is the gain, which varies sinusoidally. It is shown that the effect on the system of the two controllers is much t
In this two part paper a theory is presented in which several control problems can be solved. The theory is applicable to a general class of linear multivariable systems where the measured output does not have to be equal to the controlled output or the state. The system may be affected by nonmeasurable disturbances. Only controllers which stabilize the system and have proper transfer functions ar
The study of general linear multivariable systems, with possibly different controlled and measured outputs, is continued in this part of the paper. The structure matrices, defined in Part I, are used to solve the feedback realization problem. Feedback realizable transfer functions are then used to solve problems of "regulator type." It is shown that the solutions to problems like disturbance deeou
Least squares identification is considered from the Bayesian point of view. A necessary and sufficient condition for consistency almost everywhere is given under the assumption that the data are generated by a regression model with white and Ganssian noise.
Some possible regulators are considered for control of stochastic systems, described by a time-varying difference equation. A new suboptimal dual algorithm is proposed, and its relation to other regulators is examined. It is discussed for what kind of systems the new algorithm will be advantageous, and when simpler schemes will suffice. This discussion is illustrated by simulations, where differen
In this paper, we present new insights on classical spectral measures for heart rate variability (HRV), based on a novel method for HRV acquisition. A dynamic breathing task, where the test participants are asked to breathe following a metronome with slowly increasing frequency, allows for the acquisition of respiratory-related HRV-data covering the frequency range in which adults breathe in diffe
Minimum variance control of difference equation systems with time-varying stochastic parameters are studied. The optimal control law is derived under the assumption that all previous but not the current parameter values are known. This is used to give performance limits for dual control. In particular, it is shown that too much parameter uncertainty may cause the system to be unstable in the mean-
A counter-example is given which shows that the proof used by Fogel and Graupe (1977) to show weak consistency for the least squares method is incorrect.
This paper considers the moving of the implementation of Concurrent Pascal for the PDP‐11/45 computer to the LSI‐11 computer. The resulting implementation for the LSI‐11 computer is also discussed and described
The gelation of cellulose in alkali solutions is quite relevant, but still a poorly understood process. Moreover, the role of certain additives, such as urea, is not consensual among the community. Therefore, in this work, an unusual set of characterization methods for cellulose solutions, such as cryo-transmission electronic microscopy (cryo-TEM), polarization transfer solid-state nuclear magneti
Interactions and phase behavior of γ-globulins are of fundamental interest in biophysical and pharmaceutical research, as these are among the most abundant proteins in blood plasma. In this work, we report the characterization of the oligomeric state of bovine γ-globulin, the effective protein–protein interactions, and the colloidal stability in aqueous solution as a function of protein concentrat
In this article, we have studied the influence of the isotopic composition of the solvent (H2O or D2O) on the effective interactions and the phase behavior of the globular protein bovine serum albumin in solution with two trivalent salts (LaCl3 and YCl3). Protein solutions with both salts exhibit a reentrant condensation phase behavior. The condensed regime (regime II) in between two salt concentr
The phase behavior of protein solutions is important for numerous phenomena in biology and soft matter. We report a lower critical solution temperature (LCST) phase behavior of aqueous solutions of a globular protein induced by multivalent metal ions around physiological temperatures. The LCST behavior manifests itself via a liquid-liquid phase separation of the protein-salt solution upon heating.
Diffusion of a particle through an energy and diffusivity landscape is a very general phenomenon in numerous systems of soft and condensed matter. On the one hand, theoretical frameworks such as Langevin and Fokker-Planck equations present valuable accounts to understand these motions in great detail, and numerous studies have exploited these approaches. On the other hand, analytical solutions for
We report a real-time study on protein crystallization in the presence of multivalent salts using small angle X-ray scattering (SAXS) and optical microscopy, focusing particularly on the nucleation mechanism as well as on the role of the metastable intermediate phase (MIP). Using bovine beta-lactoglobulin as a model system in the presence of the divalent salt CdCl2, we have monitored the early sta
The dynamics of proteins in solution is a complex and hierarchical process, affected by the aqueous environment as well as temperature. We present a comprehensive study on nanosecond time and nanometer length scales below, at, and above the denaturation temperature Td. Our experimental data evidence dynamical processes in protein solutions on three distinct time scales. We suggest a consistent phy
