With increasing computational power, simulations of regional climate are now becoming possible on convective-resolving grids, thus eliminating the need for a convective parameterization. In the present study, a series of seasonal calculations using the Weather Research and Forecasting (WRF) model are computed at 4-km grid spacing, which reasonably resolves most convective systems. Simulations are computed for both the DJF and MAM seasons as averaged over 2005-2008, with a model domain covering the majority of the Amazon Basin and the adjacent South American coastline. Precipitation statistics are computed and compared to satellite rainfall retrieval data from the 13-year Tropical Rainfall Measuring Mission (TRMM) record. For comparison, a set of companion simulations with 12-km grid spacing are also computed, using the Kain-Fritsch convective parameterization. As compared to the 12-km runs, the 4-km simulations show significant improvement in the overall mean rain rate, the rain rate probability distributions, and the diurnal evolution and timing of precipitation. Both the 4-km and 12-km cases capture the coastal propagating signal and the interior basin-wide diurnal oscillation; however, the 4-km case shows better timing and evolution statistics. Compared to TRMM, the 4-km case rains too infrequently, but is more likely to produce rain events at high rain rates, thus resulting in a similar overall average rain rate. Overall, the present calculations show significant promise for computing regional rainfall patterns on convective-resolving grids.

This thesis examines the portrayal of Aboriginal Peoples in two Saskatchewan daily newspapers. This research is based on the question: "How is the notion of Aboriginal Peoples socially constructed in the print media?" Previous research indicates that media portrayals of minority groups are often partial and stereotypical. Such portrayals are partly responsible for linking the unacceptable behavior of minority groups to phenotypic traits, and thereby contributing to the social significance of "race." Discourse analysis is used to analyze 437 newspaper articles that were collected using a full-text keyword search of the EBSCO Host database, which indexes articles from the Leader Post and the Star Phoenix. In general, the results reveal that Aboriginal peoples are regularly portrayed as problematic; either as having problems themselves, or as causing problems for non-Aboriginal peoples. The results support the view that race is socially constructed and demonstrate that "race," through media discourse, can become a socially acceptable explanation for social problems.

Potato chips are very popular in the United States. Recently, an enormous interest in developing snacks from fruits and vegetables with high quality has been assessed. Mango, due to its characteristic flavor and nutritional value, is excellent for snack production. Osmotic dehydration (OD) as a pre-treatment and vacuum frying (1.33 kPa) processes were proposed to obtain high quality mango chips. Mango ?Tommy Atkins? slices were pre-treated with different OD concentrations (40, 50, and 65w/v), times (45, 60, and 70 min), and temperatures (22, 40, and 57oC). Physical and chemical properties (aw, pH, oBrix, sugar gain, water loss, and shrinkage) after OD were studied. The pre-treated slices were vacuum fried (1.33 kPa) at 120, 130, and 138oC and product quality attributes (PQA) (oil content, texture, porosity, color, microstructure, and carotenoid content) were determined. Microstructure of the chips was analyzed using an environmental scanning electron microscope. Effect of frying temperatures at optimum OD (65 w/v at 40oC) times was tested. The consumer tests showed that samples were all acceptable. The best mango chips process was the one with 65 w/v concentration for 60 min (pre-treatment) and vacuum frying at 120oC. Kinetic studies on oil content, texture, porosity, color, and carotenoid retention were performed. Oil absorption was modeled by a fractional conversion kinetic model. Absorption rate constant increased with frying temperature. Diameter changes in the chips, although not significant (P>0.05), followed an initial expansion to later decrease. Thickness of the slices increased (puffed) (around 60%) with time for all frying temperatures. Texture changes were for two frying periods: (1) water removal and crust formation and (2) slices became tougher and crispier and the end of frying. Porosity in the samples increased with frying, and a fractional conversion best described this phenomenon. Color *a (redness) increased with frying time and temperature and was modeled using a logistic model. Color *b (yellowness) increased up to 30 s of frying and then decreased. Carotenoids degradation followed a first order model, with a significant (P<0.05) decrease with frying temperature. Mango chips fried under atmospheric fryer had less carotenoid retention (25%) than with a vacuum fryer.

Weighted group algebras have been studied extensively in Abstract Harmonic Analysis.Complete characterizations have been found for some important properties of weighted group algebras, namely, amenability and Arens regularity. Also studies on some other features of these algebras, say weak amenability and isomorphism to operator algebras, have attracted attention. Hypergroups are generalized versions of locally compact groups. When a discrete group has all its conjugacy classes finite, the set of all conjugacy classes forms a discrete commutative hypergroup. Also the set of equivalence classes of irreducible unitary representations of a compact group forms a discrete commutative hypergroup. Other examples of discrete commutative hypergroups come from families of orthogonal polynomials. The center of the group algebra of a discrete finite conjugacy (FC) group can be identified with a hypergroup algebra. For a specific class of discrete FC groups, the restricted direct products of finite groups (RDPF), we study some properties of the center of the group algebra including amenability, maximal ideal space, and existence of a bounded approximate identity of maximal ideals. One of the generalizations of weighted group algebras which may be considered is weighted hypergroup algebras. Defining weighted hypergroups, analogous to weighted groups, we study a variety of examples, features and applications of weighted hypergroup algebras. We investigate some properties of these algebras including: dual Banach algebra structure, Arens regularity, and isomorphism with operator algebras. We define and study Folner type conditions for hypergroups. We study the relation of the Folner type conditions with other amenability properties of hypergroups. We also demonstrate some results obtained from the Leptin condition for Fourier algebras of certain hypergroups. Highlighting these tools, we specially study the Leptin condition on duals of compact groups for some specific compact groups. An application is given to Segal algebras on compact groups.

Head Start, an early intervention program administered by the Administration for Children and Families of the Department of Health and Human Services, offers children of low-income families comprehensive services in an effort to even the playing field with their more advantaged peers upon entering kindergarten. Despite the many areas that Head Start addresses, evaluative efforts continuously focus primarily on cognitive gains as a result of Head Start as an intervention. This study examined the potential long-term effects of the health component of Head Start. More specifically, the study investigated whether Head Start impacts a family?s ability to make positive changes in the home in the way of preventive health measures with regard to childhood obesity, immunizations, and dental health, three important areas of childhood health. Participants in the research study included children enrolled in Head Start between 2004 and 2006, and children on the waiting list within the same time. Followup interviews were conducted with families in both groups that inquired about health behaviors specifically related to childhood obesity, immunizations, and dental health. The Head Start (HS) Group and Waiting List Control (WLC) Group were compared to determine if Head Start made a difference in a family?s probability of engaging in more proactive health measures. Responses of the HS Group were also compared with responses from their initial health assessment upon enrolling in Head Start to determine if they demonstrate positive changes. Results did not support hypotheses, and in many instances the WLC Group demonstrated better proactive health measures than the HS Group. Because of operational difficulties, there is limited inference about the impact of the Head Start program. Possible contributors to the results include a small sample size due to the mobility of the target population and overrepresentation of Hispanic children in the study. Limited differences observed between the HS and WLC groups confirms the importance of further investigating the long-term impact of Head Start in areas other than cognitive gains.

Le domaine de la bioélectronique a suscité beaucoup d’intérêt ces dernières décennies grâce à sa capacité à rapprocher les mondes de l’électronique et de la biologie. La découverte dans les années 70 des polymères conducteurs a permis de combler le fossé séparant les deux mondes. Parmi les dispositifs basés sur les polymères conducteurs, les transistors électrochimiques organiques (OECTs) ont été largement utilisés pour des applications biomédicales ou comme biocapteurs. L’amplification intrinsèque apportée par le système en fait une plateforme idéale pour mesurer des signaux soumis à de fortes perturbations. La conformabilité et la flexibilité sont des paramètres clés dans le développement de capteurs implantables ou portés sur la personne. Ainsi des capteurs imprimés flexibles basés sur la technologie OECT sont prometteurs pour ces types d’application. Parmi les métabolites présents dans les fluides biologiques, les lactates sont liés à la fatigue musculaire ou les infections. Détecter ce composant est donc intéressant pour de nombreuses applications. Dans ce travail de thèse, le développement de capteurs de lactate sérigraphiés basés sur la technologie des OECTs est étudié. Une attention particulière est portée sur la possibilité d’obtenir des capteurs tout solide pour des applications portées sur la personne. Sachant que la détection d’ion peut facilement être réalisée avec des OECTs, des travaux ont été menés pour développer des capteurs multi-cibles pour le pH, et les ions Na+ et NH4+. Ces études ouvrent le champ sur des applications de diagnostic rapide en utilisant des circuits complexes intégrant des OECTs. / The field of bioelectronics has raised many interest in the past decades due to the fact that it couples the worlds of electronics to biology. The discovery of conducting polymers in the 1970’s allowed to bridge the gap between the two worlds.Among conducting polymer based devices, the organic electrochemical transistor (OECT) has been widely used for biosensing and biomedical applications. The intrinsic amplification provided by the device make it ideal platform to record signals that suffers from low signal to noise ratio. Conformability and flexibility are key parameters for implantable and wearable sensors. Thus flexible printed OECTs based biosensors are promising devices for those applications. Among metabolites present in biological fluids, lactate levels are linked with muscle fatigue or infection. Sensing this metabolite is consequently relevant for many applications. In this work, the development of a screen-printed, OECT based lactate sensor is discussed. An accent was given to obtain a wearable sensor, by designing solid state device. Moreover, since the OECT can be easily transposed to ionic detection, efforts were made towards the development of multianalyte platforms to sense pH, K+ and NH4+ ions. Those development open the way for more complex platforms based on circuits integrating OECTs. Those platforms could be used for rapid diagnostic applications with OECTs.

Computerized adaptive testing (CAT) provides a highly efficient alternative to the paper-and-pencil test. By selecting items that match examinees’ ability levels, CAT not only can shorten test length and administration time but it can also increase measurement precision and reduce measurement error. In CAT, maximum information (MI) is the most widely used item selection procedure. However, the major challenge with MI is the attenuation paradox, which results because the MI algorithm may lead to the selection of items that are not well targeted at an examinee’s true ability level, resulting in more errors in subsequent ability estimates. The solution is to find an alternative item selection procedure or an appropriate ability estimation method. CAT studies have not investigated the association between these two components of a CAT system based on polytomous IRT models. The present study compared the performance of four item selection procedures (MI, MPWI, MEI, and MEPV) across four ability estimation methods (MLE, WLE, EAP-N, and EAP-PS) under the mixed-format CAT based on the generalized partial credit model (GPCM). The test-unit pool and generated responses were based on test-units calibrated from an operational national test that included both independent dichotomous items and testlets. Several test conditions were manipulated: the unconstrained CAT as well as the constrained CAT in which the CCAT was used as the content-balancing, and the progressive-restricted procedure with maximum exposure rate equal to 0.19 (PR19) served as the exposure control in this study. The performance of various CAT conditions was evaluated in terms of measurement precision, exposure control properties, and the extent of selected-test-unit overlap. Results suggested that all item selection procedures, regardless of ability estimation methods, performed equally well in all evaluation indices across two CAT conditions. The MEPV procedure, however, was favorable in terms of a slightly lower maximum exposure rate, better pool utilization, and reduced test and selected-test-unit overlap than with the other three item selection procedures when both CCAT and PR19 procedures were implemented. It is not necessary to implement the sophisticated and computing-intensive Bayesian item selection procedures across ability estimation methods under the GPCM-based CAT. In terms of the ability estimation methods, MLE, WLE, and two EAP methods, regardless of item selection procedures, did not produce practical differences in all evaluation indices across two CAT conditions. The WLE method, however, generated significantly fewer non-convergent cases than did the MLE method. It was concluded that the WLE method, instead of MLE, should be considered, because the non-convergent case is less of an issue. The EAP estimation method, on the other hand, should be used with caution unless an appropriate prior θ distribution is specified. / text

Cai, Junpu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 49-51). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Related Works --- p.6 / Chapter 3 --- Problem Definition --- p.10 / Chapter 4 --- Preliminary Study --- p.14 / Chapter 5 --- Algorithms --- p.17 / Chapter 5.1 --- Result Caching algorithm --- p.17 / Chapter 5.1.1 --- Caching Algorithm --- p.18 / Chapter 5.1.2 --- Implementation and Maintenance --- p.20 / Chapter 5.2 --- Query Processing algorithm --- p.20 / Chapter 5.2.1 --- Join Types --- p.21 / Chapter 5.2.2 --- Operators in the Operator Tree --- p.23 / Chapter 5.2.3 --- Comparison with previous work --- p.27 / Chapter 5.2.4 --- Operator Tree (OT) for one CN --- p.28 / Chapter 5.2.5 --- Generic Operator Network (ON) --- p.30 / Chapter 6 --- Empirical Study --- p.37 / Chapter 6.1 --- Result Caching --- p.38 / Chapter 6.2 --- Comparison of Bushy and Left Deep Plans --- p.41 / Chapter 6.3 --- Comparison of ON and previous methods --- p.44 / Chapter 7 --- Conclusion and Future Work --- p.47 / Bibliography --- p.49

Pas de résumé / No summary

In this thesis, for the schema-based approaches, we propose an efficient algorithm to general all relational algebra expressions in order to find all the connected trees in an RDB. We also study an efficient algorithm to evaluate all the expressions using semijoins in RDBMS . We show that our method can also be extended to answer continuous keyword queries in a relational data stream. We further propose novel algorithms that find sets of tuples that are reachable from a root tuple within a radius, and algorithms that find multi-center subgraphs within a radius. Our algorithms use SQL queries only in order to make fully use of RDBMS. We show that the current commercial RDBMSs are powerful enough to support such keyword queries in RDBs efficiently without any additional new indexing to be built and maintained. The main idea behind our approach is tuple reduction. For the graph-based approaches, we propose an efficient algorithm to find all/top- K multi-center subgraphs in polynomial delay. We also introduce a new kind of keyword query, namely, structural statistics by keywords, to summarize keyword search results into several dimensions. We conducted extensive performance studies using two large real datasets IMDB and DBLP to show the efficiency and effectiveness of all our approaches. / Keyword search in relational databases (RDBs) has been extensively studied recently. A keyword search (or a keyword query) in RDBs is specified by a set of keywords to explore the interconnected tuple structures in an RDB that cannot be easily identified using SQL on RDBMSs. In brief, it finds how the tuples containing the given keywords are connected via sequences of connections (foreign key references) among tuples in an RDB. Such interconnected tuple structures can be found as connected trees up to a certain size, sets of tuples that are reachable from a root tuple within a radius, or even multi-center subgraphs within a radius. In the literature, there are two main approaches, namely schema-based approaches and graph-based approaches. The schema-based approaches are to generate a set of relational algebra expressions and evaluate every such expression using SQL on an RDBMS directly or in a middleware on top of an RDBMS indirectly. Due to a large number of relational algebra expressions needed to process, most of the existing works take a middleware approach without fully utilizing RDBMSs. The graph-based approaches are to materialize an RDB as a graph and find the interconnected tuple structures using graph-based algorithms in memory. / Qin, Lu. / Adviser: Jeffrey Xu Yu. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 133-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.