Closed-loop feedback systems using reduced-order models

Theorems are given to demonstrate that the tracking properties of reduced-order models obtained by Padé-type approximation methods are unchanged under constant (and dynamic) state or output feedback. Hence it follows that an optimal feedback law for the reduced-order model may be used for suboptimal control of the high-order system, with similar tracking of the output as for the open-loop case.     

Does repression exist? Memory, pathogenic, unconscious and clinical evidence.

The current dispute regarding the existence of repression has mainly focused on whether people remember or forget trauma. Repression, however, is a multidimensional construct, which, in addition to the memory aspect, consists of pathogenic effects on adjustment and the unconscious. Accordingly, in order to arrive at a more accurate decision regarding the existence of repression, studies relevant to all three areas are reviewed. Moreover, since psychoanalysis regards repression as a key factor in accounting for the development and treatment of neurotic disorders, relevant research from these two domains are also taken into account. This comprehensive evaluation reveals little empirical justification for maintaining the psychoanalytic concept of repression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time moments and Markov parameters of composite systems

A theorem is given to show that a reduced-order composite system, formed from the interconnection of a number of reduced-order models that are Padé-type approximants of some subsystems, matches the initial time moments and Markov parameters of the composite system formed from the interconnection of these subsystems. Thus the reduced-order composite system has the same tracking properties as the original composite system.     

Viability of methods for generating stable reduced order models

Various methods for generating stable reduced order models are shown to have a serious disadvantage, in that the reduced model may approximate the nondominant poles of the system and hence lead to erroneous approximations. An example is given to compare these methods with the standard Pade approximation method for which this disadvantage does not exist.     

To compute the zeros of systems

A direct method for computing the zeros of the transfer function existing between an input and an output of an arbitrary multivariable linear time-invariant system is presented.     

Synthesis of Calcium Hexaboride by Electrolysis of Molten Salt

Metallurgical and Materials Transactions B - Formation of calcium hexaboride by means of electrodeposition of boron oxide in molten CaCl2 with additives of CaO and B2O3 was analyzed. It was shown...     

Approximating the risk for time-to-failure models through using statistics of extremes

This paper studies the approximation of the partitioned multiobjective risk method's (PMRM) extreme event risk function for time-to-failure models. The analytic expression of the approximation for the extreme event risk function is derived through the use of the statistics of extremes for the case where the underlying distribution is of an extreme-value type III for minima. This analytic expression provides an effective theoretical tool for understanding the behavior of conditional expected values for time-to-failure models for a large class of distribution functions used in reliability. The results are confirmed for example problems of exponential and uniform distributions.