A New Optimization Procedure for Digital Simulation

The theory needed to define and obtain an optimized digital simulation of a given continuous system is presented in this dissertation. The frequency domain approach to simulation is used and a nonlinear function minimization algorithm, implemented on a digital computer, is incorporated to obtain the optimum simulation. The discrete transfer function obtained from z-transform theory is used to represent the digital system. The frequency domain response of this discrete transfer function can then be expressed simply as a function of frequency, for frequencies up to one-half the sampling frequency. A frequency domain error measure, in the complex plane, is defined to be the sum of the squared magnitudes of the difference in the frequency domain responses of the continuous and discrete systems at a finite number of frequencies. The coefficients of the discrete system are adjusted, by means of the function minimization algorithm, to minimize the defined error. Similar optimization procedures have been previously described. These methods, in some instances, produce an unstable, or nearly unstable, simulation of a stable continuous system. A technique is introduced here of constraining the discrete system coefficients to insure a stable simulation of a stable system. In addition, these parameters may be further restrained to keep the transient behavior of the discrete system similar to that of the system simulated. Essentially these constraints limit the time domain error while the frequency domain error is minimized. To evaluate the effectiveness of the above procedure, it is compared with the bilinear transformation and the impulse, step, and ramp invariant methods of obtaining a discrete simulation of both a first and second order continuous system. These comparisons are made in the time domain, for impulse, step, ramp, and sinusoidal inputs, as well as in the frequency domain. In addition, the effects of the constraints on the optimization technique are shown. In some instances, a small percentage increase in the frequency domain error will allow orders of magnitude decreases in the time domain errors

Portugal and the Anglo-Russian Naval Crisis (1808)

During the Napoleonic period several critical decisions had a major influence on the future of the French Empire. Unquestionably, one of the most catastrophic decisions centered around Napoleon\u27s efforts to subjugate Portugal and Spain. This in turn, forced Great Britain to commit its wealth, man­power, and ultimately its future to the struggle for control of the Peninsula. ln the initial stages of this conflict, the Royal Navy became the cutting edge of Britain\u27s new offensive

The culture and microprojection of some free-living protozoa

Thesis (M.A.)--Boston University This item was digitized by the Internet Archive

The right to freedom of religion or belief and its intersection with other rights

This paper was commissioned by ILGA-Europe, to examine how the right to freedom of religion or belief intersects with other human rights, including the rights to freedom of expression, freedom of assembly, and to be protected from discrimination and hate speech. The paper examines in particular the tension between religious freedom and the rights of lesbian, gay, bisexual, transgender and intersex (LGBTI) people, which is a matter of controversy in both legal and political discourse in Europe and elsewhere. In particular, some Christian organisations and commentators have portrayed anti-discrimination law as conflicting directly with the right to freedom of religion or belief. Such arguments are increasingly couched in terms of the asserted ‘right’ of religious individuals conscientiously to opt out of providing goods or services to same-sex couples or to express views that might be considered by others to be homophobic or transphobic. This discourse has gone so far as to characterise the scope and application of equality law as a form of religious persecution. The aim of this paper is to assist ILGA-Europe and other interested parties to respond to such arguments in a manner which is consistent with the standards and principles enshrined in both human rights and equality law, as articulated in the European Convention on Human Rights, the Charter of Fundamental Rights of the European Union, and relevant United Nations treaties and declarations, and authoritative interpretations of these instruments by the relevant courts and treaty bodies

Electronic controller for reciprocating rotary crystallizer

An electronic controller for a reciprocating rotary crystallizer is described. The heart of this system is the electronic timer circuit. A schematic along with a detailed description of its operation is given

A polypeptide bacteriophage receptor: modified cell wall protein subunits in bacteriophage-resistant mutants of Bacillus sphaericus strain P-1

Bacillus sphaericus strain P-1 has previously been shown to have a tetragonally arrayed (T layer) protein which forms the outer layer of the cell wall. The T layer was quantitatively extracted from whole cells by 6 M urea, and the T layer subunits were purified by electrophoresis of the extracts on acrylamide gels containing 0.1% sodium dodecyl sulfate or 6 M urea. Using ethylene diacrylate cross-linked gels, the T layer was found to make up 16% of the total cellular protein. A virulent bacteriophage which is inactivated by purified T layer was isolated from soil. Twenty-four phage-resistant mutants were isolated, of which 17 had T layer subunits of increased mobility on sodium dodecyl sulfate acrylamide gels. No mutants devoid of T layer were found. Mutants were grouped into six classes according to the molecular weight of their T layer subunits. These ranged from that of the wild type, 150,000 down to 86,000. Two mutants from different classes were examined in detail. Cells of the mutant strains did not adsorb phage nor did cell walls isolated from these mutants inactivate phage. The amino acid composition of the T layers from mutants differed little from that of the wild-type T layer