Recursive partitioning is embedded into the general and well-established class of parametric models that can be fitted using M-type estimators (including maximum likelihood). An algorithm for model-based recursive partitioning is suggested for which the basic steps are: (1) fit a parametric model to a data set, (2) test for parameter instability over a set of partitioning variables, (3) if there is some overall parameter instability, split the model with respect to the variable associated with the highest instability, (4) repeat the procedure in each of the daughter nodes. The algorithm yields a partitioned (or segmented) parametric model that can effectively be visualized and that subject-matter scientists are used to analyze and interpret. / Series: Research Report Series / Department of Statistics and Mathematics

With the ever increasing amount of high-throughput molecular profile data, biologists need versatile tools to enable them to quickly and succinctly analyze their data. Furthermore, pathway databases have grown increasingly robust with the KEGG database at the forefront. Previous tools have color-coded the genes on different pathways using differential expression analysis. Unfortunately, they do not adequately capture the relationships of the genes amongst one another. Structure Enrichment Analysis (SEA) thus seeks to take biological analysis to the next level. SEA accomplishes this goal by highlighting for users the sub-pathways of a biological pathways that best correspond to their molecular profile data in an easy to use GUI interface.

Esta dissertação tem por objetivo apresentar uma abordagem baseada em técnicas de inteligência artificial para automatizar a etapa de particionamento de modelos em simulação distribuída. Essa abordagem utiliza os conceitos da computação evolutiva para o desenvolvimento de um algoritmo genético capaz de otimizar o processo de particionamento e auxiliar a tomada de decisões na tarefa de obtenção dos processos lógicos. Objetiva-se com sua aplicação minimizar o tempo de execução da simulação distribuída, evitando que o pior tempo de execução seja utilizado. Para alcançar esse objetivo, o particionamento apresentado como solução é caracterizado pelo balanceamento de carga e pela baixa latência de comunicação entre processos. Isso é possível porque o algoritmo genético utiliza informações contidas no modelo e na arquitetura de onde a simulação será executada. Esses padrões são utilizados para obter informações sobre a comunicação entre processos, a carga de processamento por centro de serviço e a capacidade de processamento das máquinas / This dissertation presents an approach based on intelligence artificial technics to automatize the model partitioning stage in distributed simulation. This approach makes uses evolutive computing concepts to developed a genetic algorithmic that can optimize the partitioning process and help to take decisions in the task to get the logical process. The propose of this algorithm is reduce to execution time the distributed simulation and to avoid the use of the worst execution time. To reach this target, the partitioning obtained has characteristics such as load balance and the low-communication interprocess. This is possible because the genetic algorithmic uses as input information from the model and the architect where the simulation with be executed. These inputs are used to get information about the interprocess communication, processing load per service center and processing capacity in the machines

Um novo ciclo de tratamento térmico denominado como têmpera e partição vem sendo desenvolvido em aços com elevados teores de silício, como rota para obtenção de estruturas com frações consideráveis de austenia retida. Essa rota de tratamento m térmico consiste em realizar uma têmpera temperaturas intermediárias entre Ms e Mf, seguido de um reaquecimento com manutenção em patamares isotérmicos por certos intervalos de tempo, objetivando estabilizar a austenita remanescente através da partição do carbono a partir da martensita supersaturada. No presente trabalho, duas ligas de ferros fundidos nodulares convencionais, com diferentes teores de silício e manganês, foram submetidas a ciclos de têmpera e partição. As amostras foram austenitizadas a 900°C por duas horas. Uma das ligas foi temperada em óleo a 160°C e a outra a 170°C por 2 minutos. Imediatamente após a têmpera as amostras foram reaquecidas em temperaturas entre 300 e 450°C por intervalos de tempo que variaram entre 2 e 180 minutos. A caracterização microestrutural foi realizada através de microscopia eletrônica de varredura (MEV) e difração de raios x. A caracterização mecânica foi feita através de ensaios de energia absorvida ao impacto, dureza HRC e ensaios de tração. A caracterização microestrutural evidenciou que os ciclos de têmpera e partição são viáveis na obtenção de frações consideráveis de austenita retida nos ferros fundidos nodulares. A caracterização mecânica evidenciou que foi possível obter boas combinações de energia absorvida ao impacto, resistência à tração e alongamento. Em todas as condições testadas é possível perceber uma janela de processo bem definida caracterizada por valores crescentes das propriedades mecânicas nos primeiros minutos do ciclo de partição e que decrescem após certo intervalo de tempo. O conjunto de propriedades mecânicas obtidas através dessa rota de tratamentos térmicos indica que os ferros fundidos nodulares submetidos ao ciclo de têmpera e partição podem se constituir como alternativa tecnológica para aplicações comerciais nas quais os ferros fundidos nodulares austemperados já são materiais consolidados. / A new heat treatment cycle known as quenching and partitioning has been developed in commercial steel alloys containing silicon as a way to obtain structures with controlled fractions of retained austenite. This heat treatment cycle consists in performing a quenching in temperatures between Ms and Mf, followed by a reheating with isothermal holding by different time intervals. The aim of this cycle is to achieve the austenite stabilization by diffusion of carbon from the supersaturated plates of martensite. In this work, two conventional ductile cast iron alloys, with two different contents of silicon and manganese were heat-treated in quenching and partitioning cycle. The samples were austenitized at 900°C for two hours, followed by quenching in oil at 160° C and 170° C for two minutes. Immediately after quenching, the samples were reheated at temperatures between 300 and 450°C for time intervals between 2 and 180 minutes. The microstructural characterization was performed using electronic microscopy (SEM) and x-ray diffraction. The mechanical characterization was performed using impact tests, hardness and tensile strength tests. The microstructural characterization showed that the cycles of quenching and partitioning are viable to obtain considerable fractions of retained austenite in nodular cast by this heat treatment route. The mechanical characterization showed that it was possible to obtain good combinations of energy absorbed in the impact, tensile strength and elongation. In all tested conditions was possible to perceive a well-defined process window characterized by increasing values of mechanical properties in the first minutes of the partitioning step, and decrease after certain time intervals. The set of mechanical properties obtained by this route of heat treatments indicates that nodular cast iron subjected to tempering and partitioning cycle can be constituted as an alternative technology for commercial applications in which austempered ductile irons are already consolidated materials.

Many droplet microfluidic assays have been described in the literature over the last decade of research, however, there has been little reported industrial use of droplet microfluidics in drug discovery compound screening, and in particular that of P450 enzyme inhibition assays for profiling drug-drug interactions. This is partly for Intellectual Property reasons, since Pharmaceutical companies do not wish to give away trade secrets in a competitive market, but also because the technology is not yet 'proven' and remains in the proof-of-concept stage. In droplet microfluidics, where at least two liquid phases are encountered, it is important that leakage of material between phases is addressed. This effect has been extensively reported in the literature using fluorescent dyes, however there is very little evidence of research using large compound sets of diverse chemistry. This is probably because few researchers have access to the large pharmaceutical libraries necessary for this work. This project assessed the feasibility of translating a widely used microtitre plate-based P450 enzyme inhibition assay to droplet format; determined the extent of partitioning from droplets using a large pharmaceutical library set and attempted to model this behaviour, and thirdly, considered the pharmacological impact the droplet format may have on the assay. The P450 cytochrome 1A2 enzyme type (isoform) was chosen for translation to the micro-droplet format. Assays of this type are often conducted using fluorogenic substrates, making them favourable for relatively easy fluorescent detection in droplet format using simple optical detection assemblies. Oil selection was investigated to determine which oil systems would be better suited in respect of droplet formation. The use of surfactants in the oil phase and its impact on droplet formation was studied and the synthesis, preparation and characterisation of a custom perfluoropolyether (PFPE) surfactant ('AZF') conducted. Droplet chips were designed and fabricated to produce droplets of 200-300 µm diameter using novel channel designs and sealing techniques. The droplets were analysed by fluorescence spectroscopy using bespoke detector apparatus. Partitioning from aqueous to oil phase was studied for a small range of compounds and oils (with and without surfactant for fluorous oils). Partitioning was lowest using fluorous oils alone, and increased substantially when surfactant was included. Results from the large pharmaceutical test set suggested the percentage of compounds that may partition readily to the oil phase is low even when using surfactant. However, attempts to correlate this to known physicochemical properties and to develop a predictive model for fluorous solubility proved largely unsuccessful. Partitioning in the droplet chip using a droplet collection pooling method was difficult to quantify as a consequence of the profound impact turbulence had on partitioning. Miniaturisation of the P450 cytochrome inhibition assay to the droplet format initially gave poorly reproducible low signals. Possible causes included detector insensitivity, partitioning of reagent and/or fluorescent metabolite over longer incubation times, and binding of the 1A2 P450 cytochrome enzyme-protein at the droplet interface. Protein interaction at the droplet-oil boundary was studied by fluorescence labelling a protein contained in 200µm droplets and observing the extent of fluorescence localisation at the interface by epifluorescent and confocal fluorescence microscopy. The data from this work indicates a pronounced localisation of protein at the droplet interface, possibly leading to enzyme deactivation and the loss of signal seen for the assay in the droplet chip. A number of protein titrations were co-added to the droplets as 'blocking proteins' which were found to improve the reaction output, however were also noted to affect the pharmacology of the assay, noted by an order of magnitude shift in the reported IC50 for the test inhibitor used (fluvoxamine). The effects of compound leakage from droplets, and the possible detrimental impact on biological reagents by interaction at the droplet-oil interface, is a challenge that may limit widespread adoption of droplet MF systems in drug screening operations. Appropriate control measures and/or a means to reduce these effects are essential to enable accurate quantification with industrial drug discovery environments. The findings in this work highlight the challenges that have to be addressed for droplet microfluidic technology to be successfully incorporated into key areas of assay screening within drug discovery. In terms of further research, there is a significant requirement for the research community to delve further into these challenges and work closely with the industry sector to understand the beneficial role microfluidics can have and how to develop effective robust strategies the industry can easily adopt to progress this area of science.

abstract: The spatial databases are used to store geometric objects such as points, lines, polygons. Querying such complex spatial objects becomes a challenging task. Index structures are used to improve the lookup performance of the stored objects in the databases, but traditional index structures cannot perform well in case of spatial databases. A significant amount of research is made to ingest, index and query the spatial objects based on different types of spatial queries, such as range, nearest neighbor, and join queries. Compressed Spatial Bitmap Index (cSHB) structure is one such example of indexing and querying approach that supports spatial range query workloads (set of queries). cSHB indexes and many other approaches lack parallel computation. The massive amount of spatial data requires a lot of computation and traditional methods are insufficient to address these issues. Other existing parallel processing approaches lack in load-balancing of parallel tasks which leads to resource overloading bottlenecks. In this thesis, I propose novel spatial partitioning techniques, Max Containment Clustering and Max Containment Clustering with Separation, to create load-balanced partitions of a range query workload. Each partition takes a similar amount of time to process the spatial queries and reduces the response latency by minimizing the disk access cost and optimizing the bitmap operations. The partitions created are processed in parallel using cSHB indexes. The proposed techniques utilize the block-based organization of bitmaps in the cSHB index and improve the performance of the cSHB index for processing a range query workload. / Dissertation/Thesis / Masters Thesis Computer Science 2018

The primary air pollutant sulfur dioxide has been shown to affect plant biochemistry and physiology, although very little is known about its effects on N2-fixation in legumes. This study was designed to determine if N2-fixation, carbon partitioning , and productivity are affected under short term low level, so2 exposures. Greenhouse grown snapbeans (P has eo lus vulgaris L. cv. Ear l iwax), 29 days from planting, were exposed to 0.0, 0.4, and 0.8 parts per million sulfur dioxide for 4 hours day-l for 5 days in a fumigation chamber. At these concentrations there was no visible damage of the plant tissue and no significant changes in dry weight or yield components. Only t he 0.8 parts per million sulfur dioxide treatment reduced acetylene reduction rates but rates returned to control levels with in 2 days after the removal of the stress. Sulfur dioxide treatment increased the total carbon -14 exported from the leaves of 0.4 parts per million sulfur dioxide treated plants while the 0.8 parts per million sulfur dioxide treated plants were found to retain more of their total carbon -1 4. This retention of carbon-14 at the 0.8 parts per million level may account for the inhibit ion of acetylene reduction due to lower photosynthate supplies arriving at the root - nodules. These data suggest that low sulfur dioxide levels that would not cause any visible injury, may be interacting with carbohydrate assimilation and/or transport in P. vulgaris.

This study determined the impact of starches on the properties of low fat rennet curd as measured by microstructural and instrumental analysis. In experiment 1, 17 starches were initially screened for swelling power, impact of curd yield at 5 g/L and 10 g/L in milk, and settling in rennet-induced partially acidified low fat curd. Starches examined were narrowed down to five in experiment 2; they included: modified waxy corn starch, waxy rice starch, instant tapioca starch, dextrin, and a modified tapioca starch. These starches were added to skim milk to make rennet-induced partially acidified milk gels. Gels were made by adding starch to skim milk, heating to gelatinize starch, followed by addition of rennet and glucono-delta-lactone (GDL) to induce gelation. Once gels were set they were cut and centrifuged to sediment the curd. The amount of starch lost in whey was quantified to estimate starch retention in the curd. Confocal laser scanning microscopy was used to determine starch impact on curd microstructure. Curds yields were 13.1%, 18.4%, 20.7%, 21.5%, 23.5%, and 13.2% for control gel, and gels containing waxy corn, waxy rice, instant tapioca, modified tapioca and dextrin starches, respectively. Estimated starch retentions in the curds were 71%, 90%, 90%, 21%, and 1% for these curds. Waxy corn, waxy rice, and instant tapioca starches have the potential to improve the texture of low fat cheese because they are retained well in the protein network during coagulation and concentration of the milk proteins, and they generate interruptions in curd network that may help limit extensive protein-protein interactions. Modified tapioca starch causes the protein structure of the curd to be very loose, but it was not retained optimally in the curd. Also, because there were few distinct starch particles in the modified tapioca curd network, it is likely that when it is subjected to all the cheesemaking steps the same loose protein structure would not be observed. Dextrin was not retained well in the curd, nor did it disrupt the protein network, making it unsuitable for use in low fat cheese. In experiment 3, low fat cheddar cheeses were made with waxy corn starch, waxy rice starch, modified tapioca starch, and instant tapioca starch. Modified tapioca starch did not increase the moisture content of the cheese. Waxy corn starch, waxy rice starch, and instant tapioca starch all increased the moisture content of the cheeses significantly. However, when moisture contents of cheeses were over 61%, the body of the cheese visibly softened during storage, making the cheese very pasty. When starch-containing cheeses had moisture levels lower than that, the curd did not knit together well.

We propose in this paper an algebraic approach to hard-ware/software partitioning in Verilog Hardware Description Language (HDL). We explore a collection of algebraic laws for Verilog programs, from which we design a set of syntax-based algebraic rules to conduct hardware/software partitioning. The co-specification language and the target hardware and software description languages are specific subsets of Verilog. Through this, we confirm successful verification for the correctness of the partitioning process by an algebra of Verilog. Facilitated by Verilog’s rich features, we have also successfully studied hw/sw partitioning for environment-driven systems. / Singapore-MIT Alliance (SMA)

Thesis (Ph. D.)--Flinders University, 2006. / Title from PDF t.p. (viewed on Mar. 11, 2007). Includes bibliographical references.