Excitonic structure and pumping power dependent emission blue-shift of type-II quantum dots

In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction approach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement. In addition, an approximate self-consistent solution of the multi-exciton problem allows us to explain two pronounced phenomena: the blue-shift of the emission with pumping and the large inhomogenous spectral broadening, both of those eluding explanation so far. The results are confirmed by detailed intensity and polarization resolved photoluminescence measurements on a number of type-II samples.Comment: 11 pages, 5 figure

Use of the booklet category test to assess abstract concept formation in schizophrenic disorders

The relationship of concept formation abilities to the presence or absence of delusions in schizophrenic disorders was investigated. Twenty-six schizophrenic patients and 14 normal individuals were administered a short form of the Booklet Category Test (BCT). Patients were grouped into those with and without delusions. It was hypothesized that the delusional group would perform significantly better on the BCT (obtain lower error scores) than the nondelusional group. Normal and delusional groups obtained significantly lower BCT error scores than the nondelusional group, even when differences in IQ scores were statistically partialled out. The two schizophrenic groups also differed significantly on BCT error scores with the delusional group performing better than the nondelusional group

The subpower membership problem for semigroups

Fix a finite semigroup $S$ and let $a_1,\ldots,a_k, b$ be tuples in a direct power $S^n$. The subpower membership problem (SMP) asks whether $b$ can be generated by $a_1,\ldots,a_k$. If $S$ is a finite group, then there is a folklore algorithm that decides this problem in time polynomial in $nk$. For semigroups this problem always lies in PSPACE. We show that the SMP for a full transformation semigroup on 3 letters or more is actually PSPACE-complete, while on 2 letters it is in P. For commutative semigroups, we provide a dichotomy result: if a commutative semigroup $S$ embeds into a direct product of a Clifford semigroup and a nilpotent semigroup, then SMP(S) is in P; otherwise it is NP-complete

Prefacio

Fil: Steindl, Luis. Universidad Nacional de Cuyo. Secretaría de Desarrollo Instituciona

Evaluation and Determination of Integration Orders in Component-based Embedded Systems

Vestavěné počítačové systémy jsou stále složitější. Jedním ze způsobů, jak tuto složitost zvládnout, je komponentově založený přístup, kdy systémy jsou postaveny z jednotlivých nezávislých SW komponent. Důležitým aspektem stavby systému je jeho softwarová integrace. Klíčovým bodem integrace je pořadí, ve kterém jsou komponenty kombinovány do výsledného celku. Dosavadní vědecké práce v dané oblasti dávají pouze hrubá doporučení a spoléhají se na zkušenost návrháře. V disertační práci jsou identifikovány parametry sofwarového integračního procesu a dále je navržen optimaliyační proces, který vede k nalezení integračního pořadí, které vyžaduje nejmenší čas a náklady.Katedra informatiky a výpočetní technikyObhájenoEmbedded software systems are getting more and more complex. One answer to handle this complexity is component-based development, in which systems are built of individual independent software components. One important aspect of the component-based development approach is software integration. Individual components have to be put together and their interactions have to be verified. The crucial point of integration is the order in which components are combined. State-of-the-art approaches are only coarse guidelines and rely strongly on integrators expertise. More elaborate methods in which an algorithm is used to derive an integration order are only available for object-oriented software and cannot be directly used in procedural programming languages. To deal with these challenges, parameters are identified the software integration process is subjected to and metrics are developed in order to evaluate a certain integration order. Furthermore, an optimization approach based on simulated annealing is presented which is used to derive an integration order with respect to the proposed parameters in a powerful and reliable manner

Syrup Clarification for Plantation White Sugar to Meet New Quality Standards

There is significant interest in many sugar producing countries towards producing a higher quality plantation white or direct consumption sugar with lower colour and lower residual sulfur dioxide levels. National standards for residual sulfur dioxide and colour have been lowered to reflect the growing demand for improved quality and concerns for health risks. Investigations at SRI have focused on identifying optimum conditions for clarification options to remove scale components, colour and other impurities by clarifying intermediate and final effect syrups. Trials in two Australian factories demonstrated the benefits for improved sugar quality and productivity improvements for the pan and centrifugal stages. Recent investigations in four overseas countries have focused on the application of syrup clarification with or without syrup sulfitation to achieve compliance with the changing standards. Results show that syrup clarification technology can be used to achieve lower sugar colours and reduced residual sulfur dioxide. In one case where syrup clarification was used in conjunction with syrup sulfitation, the colour of the product sugar was reduced from about 150 IU to below 100 IU. In another case, the colour of the sugar was reduced from 150 IU down to 120 IU by replacing the syrup sulfitation process with syrup clarification. In the latter case, residual sulfur dioxide values were reduced from about 25 ppm down to about 14 ppm. There are other advantages to be derived from clarification of the raw syrup, including reduced turbidity and lower ash. A reduction in viscosity has provided productivity gains for the pan and centrifugal stations