Thesis (Ph. D.)--University of Chicago, Dept. of Physics, June 1999. / Includes bibliographical references. Also available on the Internet.

Thesis (doctoral)--Åbo Akademi University, 2005. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph.D)--Washington State University, August 2006. / Includes bibliographical references (p. 91-93).

Violet B. Haas. / Bibliography: leaf 5. / "April, 1984" / National Science Foundation grant no. R-11-8310350.

Th. 3e cycle--Math. appl.--Lille 1, 1980. N°: 869.

Thesis (MSc (Mathematics))--University of Stellenbosch, 2007. / An exposition is given of [12], a paper by N. Krupnik, which is a discussion of the minimum number of idempotent generators of a complete matrix algebra Mn(F) over a field F, as well as direct sums of complete matrix algebras over F. It will, for example, be proved that, if n ≥ 2, then the minimum number of idempotent generators of a n × n matrix algebra is equal to 2 or 3. Krupnik made an incorrect statement in ([12], Theorem 5), namely that the minimum number of idempotent generators of m copies of an infinite field F, as an algebra over F, is m−1. This error was identified and corrected by A.V. Kelarev, A.B. van der Merwe and L. van Wyk in [11]. The thesis also includes an exposition of this correction. Furthermore an exposition will be given of the main result of [5], where E. Formanek showed that, if n ≥ 2, then there is a non-vanishing central polynomial for Mn(F), with F any field. The last mentioned result will be used in the exposition of [12].

This thesis makes a comparison between the performance of Go and Java using parallelizedimplementations of the Classic Matrix Multiplication Algorithm (CMMA). The comparisonattempts to only use features for parallelization, goroutines for Go and threads for Java,while keeping other parts of the code as generic and comparable as possible to accuratelymeasure the performance during parallelization.In this report we ask the question of how programming languages compare in terms of multi-threaded performance? In high-performance systems such as those designed for mathemati-cal calculations or servers meant to handle requests from millions of users, multithreadingand by extension performance are vital. We would like to find out if and how much of a dif-ference the choice of programming language could benefit these systems in terms of parallel-ism and multithreading.Another motivation is to analyze techniques and programming languages that have emergedthat hide the complexity of handling multithreading and concurrency from the user, lettingthe user specify keywords or commands from which the language takes over and creates andmanages the thread scheduling on its own. The Go language is one such example. Is this newtechnology an improvement over developers coding threads themselves or is the technologynot quite there yet?To these ends experiments were done with multithreaded matrix multiplication and was im-plemented using goroutines for Go and threads for Java and was performed with sets of4096x4096 matrices. Background programs were limited and each set of calculations wasthen run multiple times to get average values for each calculation which were then finallycompared to one another.Results from the study showed that Go had ~32-35% better performance than Java between 1and 4 threads, with the difference diminishing to ~2-5% at 8 to 16 threads. The differencehowever was believed to be mostly unrelated to parallelization as both languages maintainednear identical performance scaling as the number of threads increased until the scaling flat-lined for both languages at 8 threads and up. Java did continue to gain a slight increase goingfrom 4 to 8 threads, but this was believed to be due to inefficient resource utilization onJava’s part or due to Java having better utilization of hyper-threading than Go.In conclusion, Go was found to be considerably faster than Java when going from the mainthread and up to 4 threads. At 8 threads and onward Java and Go performed roughly equal.For performance difference between the number of threads in the languages themselves nonoticeable performance increase or decrease was found when creating 1 thread versus run-ning the matrix multiplication directly on the main thread for either of the two languages.Coding multithreading in Go was found to be easier than in Java while providing greater toequal performance. Go just requires the ‘go’ keyword while Java requires thread creation andmanagement. This would put Go in favor for those trying to avoid the complexity of multi-threading while also seeking its benefits.

Made available in DSpace on 2014-06-11T19:25:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-25Bitstream added on 2014-06-13T18:53:26Z : No. of bitstreams: 1 carbinatto_fm_me_arafcf.pdf: 2519448 bytes, checksum: 2e3afb3985cd01b53141ffd3dd03d09f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dentre os sistemas de liberação controlada de fármacos, as matrizes hidrofílicas destacam-se pela possibilidade de incorporação de grandes quantidades de fármaco, economia e facilidade de processamento e obtenção de perfis de liberação reprodutíveis. A alta amilose e a pectina são exemplos de materiais utilizados na obtenção de matrizes hidrofílicas, ou seja, aquelas que absorvem água e formam uma camada de gel, antes de se dissolverem. No entanto, durante o intumescimento pode ocorrer a ruptura das ligações que mantêm a integridade da rede polimérica, o que compromete o controle da liberação. Tal efeito pode ser evitado através da reticulação, a qual promove a introdução de ligações intercadeias permanentes, que mantêm a integridade da rede tridimensional. Recentemente, em nossos laboratórios, a alta amilose foi reticulada com trimetafosfato de sódio (TMFS), originando sistemas sólidos não compactados que prolongaram a liberação do diclofenaco por até 24h. A pectina, polissacarídeo amplamente empregado na indústria alimentícia e farmacêutica, também pode ser reticulada pelo mesmo reagente, inclusive em misturas com a alta amilose. Sendo assim, o objetivo deste trabalho foi obter e caracterizar misturas de alta amilose e pectina em diferentes proporções, reticuladas com TMFS em diferentes graus (diferentes condições reacionais). A caracterização foi realizada por análises de reologia, intumescimento, difratometria de raios X e análise térmica. O desempenho como sistemas de liberação controlada de fármacos foi avaliado através da determinação da liberação in vitro de nimesulida a partir de comprimidos. O conjunto de resultados mostrou que todas as amostras apresentaram um comportamento de gel covalente, além de indicar a ocorrência de mudanças estruturais na rede... / Among controlled drug delivery systems, the hydrophilic matrices stand out for the possibility of incorporating large amounts of drug, economy and ease of processing, and obtaining reproducible release profiles. High amylose and pectin are examples of materials used for preparing hydrophilic matrices, i. e., those which absorb water and build a gel layer, before dissolving. However, during the swelling the rupture of the linkages that maintain the integrity of the polymer net can occur, compromising the release control. Such effect can be avoided by means of cross-linking, which introduces permanent interchain linkages, preserving the integrity of the tridimensional net. Recently, in our laboratories, high amylose was cross-linked with sodium trimethaphosphate (STMP), leadinf the formation of non compacted solid systems, which prolonged the diclofenac release for up to 24h. Pectin, polysaccharide widely used in the food and pharmaceutical industries, can be also crosslinked by the same reagent, including in mixtures with high amylose. Thus, the objective of this work was obtaining and characterizing mixtures of high amylose and pectin in different ratios, cross-linked with STMP in different degrees (different reactional conditions). Characterization included analyses of rheology, swelling behavior, X-ray diffractometria and thermal analysis. The performance of the systems in controlling drug release was assessed by the in vitro release of nimesulide from tablets. The results set showed that all samples presented a covalent gel behavior, as well as indicated the occurrence of structural changes within the tridimensional net in both the cross-linked and non cross-linked samples. However, cross-linked samples presented characteristics of stronger gel, as well as higher degree of crystallinity and and higher thermal stability. The samples... (Complete abstract click electronic access below)

University of Macau / Faculty of Science and Technology / Department of Mathematics

Q-Beta phage RNAs with inactivating insertion (8 base) or deletion (17 base) mutations within their replicase genes were transfected into Escherichia coli spheroplasts containing QB replicase provided in trans by a resident plasmid. Replicase-defective (Rep~) Q3 phage produced by these spheroplasts were unable to form plaques on cells lacking this plasmid. When individual Rep~ phage were isolated and grown to high titer in cells containing plasmid derived Q3 replicase, revertant Q3 phage (Rep'), with the original mutation (insertion or deletion) repaired, were obtained at a frequency of ca. 1 x 108. RNA recombination via a "template switching" mechanism involving Q3 replicase, the mutant phage genome, and the plasmid-derived replicase mRNA was shown to be the primary means by which these mutant phages reverted to wild type.