Besides the traditional face-to-face learning medium, online media are now available for students in various learning environments. The delivery of coursework through online media is on the increase in colleges and universities. However, research on the use of online learning media in beginning collegiate level foundational mathematics courses for non-mathematics and non-science majors is limited. Therefore, the purpose of this study was to investigate, within a foundational mathematics course, connections between media used for instruction in hybrid and online enhanced face-to-face learning environments and students’ media preferences. The online Web Course Tools (WebCT) Vista template used in this study was designed by the researcher and her colleague as a part of the hybrid fellowship project for a two-year college. Applying transactional distance theory and engagement theory, designers carefully analyzed each concept and determined which concepts would be delivered most effectively in each learning medium. This study was quantitative in nature. During Fall 2005, thirty-eight students in the Introduction to Mathematical Modeling course at a community college in the southeast participated in the final study. Students in the hybrid sections comprised the treatment group while students in the online face-to-face section comprised the control group. Throughout the semester, all students were asked to respond to questions on the following instruments: Assignment Feedback, Quiz Feedback, Test Feedback, and Project Feedback. Chi-Square analysis showed that significant differences were found in the majority of items on the Test Feedback instrument related to the linear and quadratic modules. In general, the treatment group preferred online learning at least half of the time and believed online resources provide the basic resources for learning the subject matter. Students’ written responses from the treatment group indicated that both online learner-content interactions, and in-class learner-instructor interactions supplemented the learning of mathematics. The control group preferred predominantly face-to-face learning and believed that learning primarily took place in a physical setting. The findings showed that the proportion of students who completed the course using the hybrid and face-to-face learning environments was not significantly different. Therefore, the data showed the success rate for both learning environments was about the same.

Recently designated as a bioenergy crop, Sorghum is rather unique as it can produce large quantities of cellulose or sugar which can be used to produce advanced biofuels or compounds. Sweet sorghum contains high levels of sugars and biomass sorghums consist primarily of ligno-cellulosic biomass. Improvement of both sorghum types is essential for maximizing production and conversion efficiency. Photoperiod sensitive sorghum is thought to maximize biomass production yet maturity influence on biomass production and composition is not fully understood. Utilizing sorghum for sugar production has increased efforts to develop sweet sorghums with sugar yields similar to sugarcane. Hybridization of these species has been investigated with, until recently, little success. Testing newly developed intergeneric hybrids and improvement of parents used in their creation will determine their feasibility and improve hybrid performance. Objectives of this research are multifaceted. First, analyze photoperiod sensitive sorghum in varying day length environments to determine maturity effects on plant phenotype, composition, and QTL detection. Second, analyze intergeneric sorghum × sugarcane hybrids to determine agronomic performance in relation to sugarcane. Lastly, introgress the iap allele into sweet sorghum females for use in intergeneric hybrid creation. Photoperiod sensitive sorghum RILs were evaluated in College Station and Weslaco, Texas and Puerto Rico which caused differential expression of plant maturity. Genetic control of trait expression was high for each location. Results indicate gradual induction of plant maturity increases detection of phenotypic QTL and detection of compositional QTL increases when maturity effects on plant phenotype are reduced. Intergeneric sorghum × sugarcane F_1 hybrids were compared to sugarcane in Weslaco, Texas in 2011. Each hybrid expressed agronomic traits similar or better than that of the sugarcane variety. High levels of repeatability and genetic influence on trait expression were observed. Overall performance of the sugarcane variety was better than any individual hybrid tested. Introgression of iap into sweet sorghum was successful and generated seventeen new sweet sorghum female genotypes possessing the allele. Only two genotypes exhibited higher brix readings and both were later maturing than Tx3361. Height and maturity of all developed genotypes varied and desirability of developed lines was similar to Tx3361.

This thesis describes the application of the stochastic-flow-modeling (SFM) approach to represent the quality behavior of a manufacturing system. Initially, a simple, one-product type SFM is discussed and then a more complex multiple-product manufacturing system is developed. This quality SFM-based model has aggregation by station, product, and operational shift. Subsequently, potential supervisory control architectures that could be used in conjunction with this quality-based SFM are discussed and developed. Distribution parameter fitting is explored using static and adaptive approaches and a comparison between these two approaches is given. Then, the accuracy of the SFM modeling technique is demonstrated using two simulation examples. Effective equipment maintenance is essential for a manufacturing plant seeking to produce high quality products. The impact of equipment reliability and quality on throughput have been well established, but the relationship between maintenance and quality is not always clear nor direct. Therefore, after developing a SFM to represent the quality of a manufacturing system, the focus of this work shifts towards identifying correlations between maintenance and quality. This thesis describes a statistical modeling method that makes use of a Kalman filter to identify correlations between independent sets of maintenance and quality data. With such a method, maintenance efforts can be better prioritized to satisfy both production and quality requirements. In addition, this method is used to compare results from the theoretical maintenance-quality model to data from an actual manufacturing system. Results of the analysis indicate the potential for this method to be applied to preventive, as well as reactive maintenance decisions, since ageing aspects of equipment are also considered in the model. / Thesis (Master, Chemical Engineering) -- Queen's University, 2008-06-25 11:18:16.925

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The yield of short-season hybrids is lower than long-season hybrids, mainly as a result of the low final leaf area developed by the short-season plants. This is due to the smaller plant stature and smaller leaf number and size of short-season adapted hybrids. In addition, in short-season areas the thermal-time available may be insufficient to mature grain of current maize hybrids. Maize hybrids which accumulate leaf area quickly, mature earlier, yield well and tolerate higher population densities better than the currently available hybrids would be more suitable for production in short-season areas. The "Leafy reduced-stature" maize hybrids, which have only recently been developed, have traits which address these criteria. There has been no previous effort to evaluate the effects of more than two plant population densities or the effects of planting patterns on the yield, yield components and vegetative growth of these hybrids. in 1995, field experiments were conducted at two sites near Montreal to compare the response of leafy reduced-stature (LRS), non-leafy normal stature (NLNS), and non-leafy reduced-stature (NLRS) maize hybrids to plant population densities and planting patterns. LRS maize hybrids showed the most rapid growth of the first ear, and the highest yield per single plant and per hectare at high plant population densities in paired rows. LRS hybrids also had longer grain filling periods, lower grain moisture contents and higher harvest indices than conventional (NLNS) hybrids. Rapid growth of the first ear and a higher harvest index are indications that LRS hybrids should be more tolerant of higher population densities than currently available hybrids. Therefore, LRS hybrids show promise for production in short-season areas at high plant population densities where maize cultivation is not currently economical due to shortness of the growing-season.

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Natural hybrid zones provide opportunities to study a range of evolutionary phenomena from speciation to the genetic basis of fitness-related traits. Additionally, investing the structure of hybrid zones can provide valuable insight in the ecology and evolution of species. The present dissertation approaches the investigation of natural hybrid zones between Xiphophorus birchmanni and X. malinche from a population genetics perspective. The goal of the chapters herein are to investigate the genetic structure of these natural hybrid zones overall and the genetic structure of the populations within them in an effort to better understand the factors producing and maintaining spatial genetic patterns among this species pair and their hybrids. Using informative single nucleotide polymorphisms (SNPs) in one mitochondrial and three nuclear intron loci, I show that hybrid zones occur in replicated fashion in multiple stream reaches along a gradient from high to low elevation. Tests of FIS and linkage disequilibrium (LD) revealed significant genetic structure within a small subset of populations. Specifically, parentals and hybrids all three occur in some locations while other locations appear to be hybrid swarms. I then investigated a behavioral mechanism of reproductive isolation - social association, which might affect population structure. In clean water, individuals shoaled significantly more closely with conspecifics. Additionally, genotyping of females and their embryos revealed signatures of non-random mating in structured populations. Taken together, assortative social grouping, which may translate to assortative female mate choice, likely plays a role in maintaining population structure. Finally, I show that fluctuating asymmetry is significantly higher in unstructured than structure populations. This is a further indication that some form of non-random mating occurs in structured populations and has effects on male phenotypes.

Lean Manufacturing has proven to be a very successful strategy for achieving production efficiencies. The basic elements of lean manufacturing are flow and pull. The traditional methods for establishing flow and pull do not fit well in the realm of high variety low volume manufacturing systems. This thesis provides a general framework for establishing flow and pull in high variety low volume manufacturing systems, through the concept of hybrid flow layouts. The existing analytical procedure for forming hybrid flow layouts is described and a new heuristic procedure, that overcomes some of the limitations of the existing procedure, is proposed. The performance of the new procedure in comparison to the existing procedure is illustrated using a real world case study. Finally, certain practical implementation issues that affect the formation of hybrid flow layouts are provided.