Este trabalho faz uma avaliação preliminar do possível impacto ambiental causado pela utilização de grupos motogeradores movidos a diesel em uma Região Metropolitana como São Paulo, que sofre com uma forte degradação da qualidade do ar, provocada por poluentes semelhantes aos emitidos por estes equipamentos, provenientes das emissões geradas por veículos automotores leves e pesados e por processos industriais. Durante o desenvolvimento deste trabalho foi feita uma revisão dos principais conceitos de poluição do ar relevantes para análise da situação, bem como uma pesquisa da qualidade do ar na Região Metropolitana de São Paulo, com base nos relatórios de Qualidade do Ar emitidos pelo órgão de controle ambiental. Foram elaborados inventários e diagnósticos relativos aos grupos motogeradores cadastrados pela concessionária de energia elétrica e pelo órgão de controle ambiental, constando as características técnicas e estimativas das emissões de poluentes atmosféricos destes grupos. Ainda foram identificadas metodologias de avaliação do impacto ambiental provocado por estas emissões. Finalmente, em face da ausência de regulamentação ambiental específica para grupos motogeradores, discutiu-se a necessidade da adoção de medidas de controle para este tipo de fonte de poluentes atmosféricos. / This work makes a preliminary evaluation of the possible environmental impact caused by the use of motogenerator groups moved by diesel in a metropolitan region as São Paulo, that suffers a strong degradation in its air quality, provoked by pollutants similar to the ones emitted by these equipments, proceeding from the emissions generated by light and heavy weighing vehicles and industrial processes. During the development of this work the main concepts of air pollution relevant to the analysis of the situation were reviewed. A research of the air quality in the Metropolitan Region of São Paulo was realized based on the Air Quality Reports emitted by the Agency of Environmental Control. Inventories and diagnosis relative of motogenerator groups registered by the Concessionaire of Electric Energy and the Agency of Environmental Control were elaborated and evidenced the technical characteristics and estimates of the emissions of atmospheric pollutants of these groups. Methodologies for the evaluation of environmental impacts provoked by these emissions were also identified. Finally, face to the absence of environmental regulations specific to these motogenerator groups, the adoption of controlling measures for this type of environmental pollutants source was discussed.

In this thesis, learning refers to the intelligent computational extraction of knowledge from data. Supervised learning tasks require data to be annotated with labels, whereas for unsupervised learning, data is not labelled. Semi-supervised learning deals with data sets that are partially labelled. A major issue with supervised and semi-supervised learning of data streams is late-arriving or missing class labels. Assuming that correctly labelled data will always be available and timely is often unfeasible, and, as such, supervised methods are not directly applicable in the real world. Therefore, real-world problems usually require the use of semi-supervised or unsupervised learning techniques. For instance, when considering a spam detection task, it is not reasonable to assume that all spam will be identified (correctly labelled) prior to learning. Additionally, in semi-supervised learning, "the instances having the highest [predictive] confidence are not necessarily the most useful ones" [41]. We investigate how self-training performs without its selective heuristic in a streaming setting. This leads us to our contributions. We extend an existing concept drift detector to operate without any labelled data, by using a sliding window of our ensemble's prediction confidence, instead of a boolean indicating whether the ensemble's predictions are correct. We also extend selective self-training, a semi-supervised learning method, by using all predictions, and not only those with high predictive confidence. Finally, we introduce a novel windowing type for ensembles, as sliding windows are very time consuming and regular tumbling windows are not a suitable replacement. Our windowing technique can be considered a hybrid of the two: we train each sub-classifier in the ensemble with tumbling windows, but delay training in such a way that only one sub-classifier can update its model per iteration. We found, through statistical significance tests, that our framework is (roughly 160 times) faster than current state of the art techniques, and achieves comparable predictive accuracy. That being said, more research is needed to further reduce the quantity of labelled data used for training, while also increasing its predictive accuracy.

Este trabalho faz uma avaliação preliminar do possível impacto ambiental causado pela utilização de grupos motogeradores movidos a diesel em uma Região Metropolitana como São Paulo, que sofre com uma forte degradação da qualidade do ar, provocada por poluentes semelhantes aos emitidos por estes equipamentos, provenientes das emissões geradas por veículos automotores leves e pesados e por processos industriais. Durante o desenvolvimento deste trabalho foi feita uma revisão dos principais conceitos de poluição do ar relevantes para análise da situação, bem como uma pesquisa da qualidade do ar na Região Metropolitana de São Paulo, com base nos relatórios de Qualidade do Ar emitidos pelo órgão de controle ambiental. Foram elaborados inventários e diagnósticos relativos aos grupos motogeradores cadastrados pela concessionária de energia elétrica e pelo órgão de controle ambiental, constando as características técnicas e estimativas das emissões de poluentes atmosféricos destes grupos. Ainda foram identificadas metodologias de avaliação do impacto ambiental provocado por estas emissões. Finalmente, em face da ausência de regulamentação ambiental específica para grupos motogeradores, discutiu-se a necessidade da adoção de medidas de controle para este tipo de fonte de poluentes atmosféricos. / This work makes a preliminary evaluation of the possible environmental impact caused by the use of motogenerator groups moved by diesel in a metropolitan region as São Paulo, that suffers a strong degradation in its air quality, provoked by pollutants similar to the ones emitted by these equipments, proceeding from the emissions generated by light and heavy weighing vehicles and industrial processes. During the development of this work the main concepts of air pollution relevant to the analysis of the situation were reviewed. A research of the air quality in the Metropolitan Region of São Paulo was realized based on the Air Quality Reports emitted by the Agency of Environmental Control. Inventories and diagnosis relative of motogenerator groups registered by the Concessionaire of Electric Energy and the Agency of Environmental Control were elaborated and evidenced the technical characteristics and estimates of the emissions of atmospheric pollutants of these groups. Methodologies for the evaluation of environmental impacts provoked by these emissions were also identified. Finally, face to the absence of environmental regulations specific to these motogenerator groups, the adoption of controlling measures for this type of environmental pollutants source was discussed.

The popularity of capillary electrophoresis (CE) as a separation technique has been established over the years. CE offers the advantages of high resolution, high separation efficiency, fast approaches of method development, a range of operational modes and low consumption of reagents. The strategy employed here for the development of chromatographic separations involved the utilization of experimental designs, multi-linear regression and response surface methodology to build empirical models that related the chromatographic quality to the factors influencing the separation. Separation of Nitrofuran antibiotics (NFAs) and their metabolites (NFMs) by using micellar electrokinetic capillary chromatography was successfully completed. The best conditions found to give optimum resolution from the optimization study was pH 9.0, 80 mM SDC concentration, 16 kV with running buffer consisting of 20 mM borate and 20 mM phosphate concentration using a 73 cm x 75 ƒÝm column, resulting in completely resolved NFAs and NFMs within 16 min. It is interesting that all the compounds can be reliably separated with the one mixture, and single CE condition. Whilst all antibiotics have shorter migration time than their respective derivatised metabolites, as a group apart from nitrofurantoin the antibiotics elute before the metabolites. The analytical figures of merit for CE analysis exhibited excellent reproducibility of absolute and relative migration times, and acceptable reproducibility of relative response areas. Successful separation of metabolite derivatives was achieved when the developed method was applied to a spiked prawn sample. The chiral separation of Triadimenol was successfully completed using micellar electrokinetic capillary chromatography. The best conditions found to give optimum resolution from the optimisation study were pH 6.0, 20% methanol, 50 mM SDS concentration, 18 kV with running buffer consisting of 20 mM borate and 20 mM phosphate concentration using a 64.5 cm x 50 ƒÝm column, resulted in baseline resolution of all Triadimenol isomers within 18 min. The optimised separation conditions were applied to a blank grape sample and to a spiked grape sample. No peaks were observed in the blank grape sample whereas the spiked grape sample had two diastereoismer peaks with poor detection sensitivity. Increase in detection sensitivity is necessary to determine the possibility of resolution of all the isomers of Triadimenol, in the spiked grape sample and the blank. Online preconcentration techniques were attempted to for Triadimenol isomer separation. When using online preconcentration technique of sweeping, a 30-fold increase in detection sensitivity of Triadimenol was observed compared to MEKC mode. However enantiomer separation was not possible with sulfated-£]-CD chiral selector. The best conditions were found to be pH 2.5, 50 mM SDS concentration, -20 kV with running buffer consisting of 20 mM phosphate concentration, using a 64.5 cm x 50 ƒÝm column, resulting in diastereoisomer separation within 8 min. Final stage of the project was to create stationary phase beds in capillaries and micro-channels that could be removed and re-created, thus providing a fresh stationary phase. The replaceable stationary phase (RSP) can be used as an operating mode of CE/CEC. Preparation of reversible stationary phase (RSP) inside the capillary column was successfully performed using low methoxy pectin (LMP). LMP renders a capability of reversible thermogelation. Electroosmotic flow (EOF) and sufficient hydrophobicity of LMP gel allow separation of analyates. The porosity of LMP RSP was adequate to support EOF. Successful separation with good reproducibility of areas and migration times was obtained for Caffeine, Aspartame, Benzoic acid, Saccharine (CABS) mixture and NFAs. After performing continuous analyses, the aging of RSP was observed. Temperature was the ¡¥switch¡¦, which applied to remove aged RSP. RSP was recreated for further analysis of analytes. RSP was UV transparent, capable of handling various analytes and diff erent buffer electrolytes including aqueous-organic solvents.

This paper focuses on the issue of sampling directly from the stationary distribution of Vervaat perpetuities. It improves upon an algorithm for perfect sampling first presented by Fill & Huber by implementing both a faster multigamma coupler and a moving value of Xmax to increase the chance of unification. For beta = 1 we are able to reduce the expected steps for a sample by 22%, and at just beta = 3 we lower the expected time by over 80%. These improvements allow us to sample in reasonable time from perpetuities with much higher values of beta than was previously possible.

Jorda (2005) proposed the new method to estimate impulse response functions by local projection. The new method, local projection, can avoid the misspecification problem. That is, local projections are robust to misspecification of the data generating process (DGP). Wu, Lee, and Wang (2008) extended the Jorda¡¦s local projection from stationary time series I(0) to non-stationary time series I(1). It makes the local projection be a more generally applicative method for the Macroeconomic. In the article, I relax the cointegration vector which assumed to be known in the Wu, Lee, and Wang (2008) and Lee(2010). From the inference of Johansen (1995) I can get the property of super-consistent between £] and ˆ £] in the cointegration vector. I use the above condition and OLS to estimate impulse response functions, and in the asymptotic theorem, the cointegration vectors which assumed to be known or estimated by Johansen MLE are both get the consistent coefficients of impulse responses.

Thanks to development of power semiconductor devices and integrated circuits, active front-end converters with controllability of bidirectional power flow have become popular and viable in industrial applications. This thesis proposes an improved resonant current control for the active front-end converter with LCL filter. The proposed control consists of a band-pass filter tuned at fundamental frequency and various band-rejected filters resonant at harmonic frequencies to provide fundamental current tracking capability as well as enhance harmonic current rejection. Based on this algorithm, the active front-end converter can control dc voltage with unity power factor by sensing converter output current, LCL filter voltage and dc voltage. This approach also conducts harmonic current rejection under distorted line voltage with no phase-locked-loop used, which is the significant advantage in terms of phase lag of frame transformation and computing effort of digital signal processing. Current tracking performance and harmonic rejection capability of the proposed method are verified based on frequency-domain analysis. Computer simulations and experimental results are also implemented to validate effectiveness.

Inspired by promotion of commercial applications, support of location-based services to mobile terminals through their current location has been receiving a lot of attention in recent years even though emergency communications is the primary motivation for development of wireless location. A major challenge to wireless location technique is how to balance the implementation complexity and required accuracy. In the first part of this dissertation, we address one of the fundamental problems in wireless location when using the ToA measurements and develop a simple model to estimate the mobile terminal location with low complexity and promising accuracy. The model employs the geometrical transformation method with single propagation delay measurement. The contribution is that the use of geometrical transformation allows us to overcome the location handover problem, i.e., a forcing handover in a GSM (global system for mobile) network or a three-way soft handover in a UMTS (universal mobile telecommunications system) network. By using the proposed location model, the impact on network performance is kept at the minimum level and the complexity and requirements for hardware and software changes are reduced. In the second part of this dissertation, we address one of the fundamental problems in wireless location when using the SS (signal strength) measurements. The first contribution is to develop a novel wireless location technique based on a ¡§differ- encing¡¨ way, called the SSSD (stationary signal-strength-difference), to remove the uncertainty propagation parameters when merging environment-dependent signal propagation model into the location estimation. This is due to the uncertainty in propagation parameters causes a propagation model error that enlarges error in the distance estimation. The performance gained from the preliminary analysis of SSSD location technique, however, is degraded as a result of the large bias error in the estimated distance and distance difference. To achieve the performance enhancement, the second contribution is to correct the bias error in the estimated distance difference by using a correction method based on a geometric constraint condition. With the corrected distance difference, the final contribution is that we generalized the work on correction method and provide a new framework to correct the error in the estimated distance. As the corrected distance and distance difference is derived by LS (least square) computation, respectively, low computation burden and non-iterative solutions were achieved. To the best of our knowledge thus far, this is first such proposal for a correction to the SS-based location technique. It is demonstrated that the proposed error correction method is shown to perform well when encountering the large error in the estimated distance and distance difference, and prove that the location accuracy can be improved considerably.

Abstract not available. / text

The Whelk-O1 chiral stationary phase is widely used in liquid and supercritical chromatography for the separation of enantiomers. The enantioselective mechanism of the Whelk-O1 chiral stationary phase is the main focus of this thesis. Semi-flexible models are developed based on ab initio calculations for the Whelk-O1 selector and a series of chiral analytes. Extensive molecular dynamics simulations are then applied to study the solvation, selectivity and in silico optimization of the chiral stationary phase. The solvation of the Whelk-O1 chiral stationary phase has been explored in a normal phase n-hexane/2-propanol solvent, a reversed phase water/methanol solvent, and a supercritical CO2/methanol solvent. We found that, in all three solvents, the Whelk-O1 selectors are open to the bulk, indicating readiness for docking of analyte. Significant solvent partitioning at the interfaces was noticed, which generates a polarity gradient between the stationary phase and the bulk, and may encourage a high analyte concentration at the interface. Hydrogen bonding activities on the amide hydrogen, amide oxygen, and nitro oxygen of the Whelk selector have also been analyzed. The selectivity of the Whelk selector was studied by molecular dynamics simulations of analyte docking on the chiral stationary phase. The elution orders and the separation factors for a series of analytes were predicted successfully. We found that hydrogen bonding and π-π stacking interactions are essential for the enantioselectivity as they are strong and specific, and they hold analytes to the cleft region of the Whelk selector. Other interactions, both stabilizing interactions such as the CH-π interaction and the edge-to-face π-π interaction, and destabilizing interactions such as steric hindrance and unfavorable conformational changes also contribute to the enantioselectivity. We identified a dominant docking arrangement for the most retained enantiomers. Other docking arrangements were found to be more frequent for the least retained enantiomers and these involve interactions with alternative selector sites. Based on the identified enantioselective mechanism obtained from the study, an optimization of the Whelk-O1 chiral stationary phase was undertaken and in silico evaluation of the modified chiral stationary phases was carried out. It was demonstrated that restriction of the alternative docking arrangements for the least retained enantiomers could possibly improve the enantioselectivity of the chiral stationary phase. / Thesis (Ph.D, Chemistry) -- Queen's University, 2008-10-08 11:54:20.249