archives@tulane.edu / The Feynman diagrams have become a highly valued tool for complex calculations and understanding the physics of elementary particles within the framework of quantum field theory. In this thesis, we present an overview on constructing and utilizing Feynman diagrams in quantum field theory along with an overview of quantum field theory itself. We begin with a review of prerequisite topics then progress to discussing symmetries using Lie groups, algebras, and representation theory. We then use the representations of the Lorentz group to derive the fields in a classical context then proceed with quantization to create the corresponding quantum fields while providing a thorough analysis of each quantum field. Path integrals are constructed for each quantum field by deriving their propagators then the formulas for scattering are derived in the context of quantum field theory. Quantum symmetries are briefly explored with the intention of quantizing classical results such as Noether's theorem. Then we construct interacting quantum field theories and introduce the Feynman diagrams and Feynman rules for different interaction theories and provide examples and applications of the Feynman diagrams. The physics behind the diagrams is carefully analyzed and interpreted. Finally, we conclude this thesis with a summary of what we have covered along with possible routes of study after mastering the contents of this thesis that will lead to current research topics. / 1 / Junhyup Sung

To make computational thinking appealing to young learners, initial programming instruction looks very different now than a decade ago, with the increasing use of graphics and robots both real and virtual. After the first steps, children want to create interactive programs, and they need a model for this. State diagrams provide such a model, as observed previously by other researchers. This thesis documents the design and implementation of a Model-Driven Engineering tool, SD~Draw, that allows even primary-aged children to draw and understand state diagrams, and create modifiable app templates. We have tested this with grade 4 and 5 students. In our initial test, we discovered that children very quickly understand the motivation and use of state diagrams using this tool, and will independently discover abstract states even if they are only taught to model using concrete states. To determine whether this approach is appropriate for children of this age we asked three questions: do children understand state diagrams, do they understand the role of reachability, and are they engaged by them. We found that they are able to translate between different representations of the state diagrams, strongly indicating that they do understand them. We found with confidence p=0.001 that they do understand reachability by refuting the null hypothesis that they are creating diagrams randomly. And we found that they were engaged by the concept, with many students continuing to develop their diagrams on their own time after school and on the weekend. / Thesis / Master of Science (MSc)

No description available.

This thesis addresses two important aspects of automatic assembly viz., assembly sequence planning and assembly path planning. These issues are addressed separately starting with sequence planning followed by assembly path planning. For efficient assembly without feedback systems (or, passive assembly), an assembler should know the ideal orientation of each component and the order in which to put the parts together (or, assembly sequence). A heuristic is presented to find the optimal assembly sequence and prescribe the orientation of the components for a minimum set of grippers = ideally one. The heuristic utilizes an index of difficulty (ID) that quantifies assembly. The ID for each task in the assembly process is computed on the basis of a number of geometrical and operational properties. The objective of the optimization problem here is to minimize the assembly ID and categorize parts/subassemblies based on their preferred direction of assembly while allowing re-orientation of the base part. It is assumed that the preferred direction of assembly is vertically downward, consistent with manual as well as most automatic assembly protocols. Our attempt is to minimize the number of degrees of freedom required in a re-orienting fixture and derive the requirements for such a fixture. The assembly of a small engine is used as an example in this study due to the variety of ideally rigid parts involved. In high precision assembly tasks, contact motion is common and often desirable. This entails a careful study of contact states of the parts being assembled. Recognition of contact states is crucial in planning and executing contact motion plans due to inevitable uncertainties. Dr. Jing Xiao of UNCC introduced the concept of principal contacts (PC) and contact formation (CF) for contact state recognition. The concept of using CFs (as sets of PCs) has the inherent advantage that a change of CF is often coincident with a discontinuity of the general contact force (force and torque). Previous work in contact motion planning has shown that contact information at the level of PCs along with the sensed location and force information is often sufficient for planning high precision assembly operations. In this thesis, we present results from experiments involving planned contact motions to validate the notion of PCs and CFs -- an abrupt change in general contact force often accompanies a change between CFs. We are only concerned with solving the 2D peg-in-corner problem. / Master of Science

A new methodology is proposed to obtain the forming limit diagram (or FLD) of sheet materials by utilizing routinely obtained experimental load versus displacement traces and incorporating finite element (FE) analysis of strain history to extract the characteristic points of diffuse and localized necking and further the limit strains. The experimental data from hemispherical punch stretching test such as limit dome height, maximum load and location of inflection point are utilized to adjust the load curves in the FE simulations. An optimization procedure to obtain various parameters in material definition has been established to obtain a good agreement between the FE-based and experimental punch load versus displacement curves. An analysis of FE model based strain history is then carried out to determine the limit strains. This approach avoids using experimental strain measurement in the vicinity of the neck on the dome specimens. The materials tested with the new methodology include automotive sheets AA6111-T4, AA6181-T4 and DP600. The one utilized for optimization of FE inputs was AA6111-T4. The proposed method for FLD determination considers out-of-plane displacement, punch-sheet contact and friction, and avoids the use of a rather arbitrary inhomogeneity factor to trigger localization such as in the Marciniak-Kuczynski method. A new criterion to determine the localized necking is proposed by seeking an inflection point m the major strain rate curve, or, maximum point in the second order of derivative of major strain, (ε1)max. The proposed localized necking criterion is compared with other two methods to determine the onset of localized necking. These are (i) Bragard criterion for post-test of deformation, and (ii) critical major strain (ε1)cr based on comparison of strain of material inside the localized site and its vicinity in the un-necked site. The new criterion of (ε1)max exhibits a more definite physical meaning towards developing an understanding of flow localization, formability and fracture. This new approach for obtaining FLDs is rapid and accurate and could be implemented easily for routine FLO generation in a lab setting with little user input and subjectivity. / Thesis / Doctor of Philosophy (PhD)

No description available.

It has been well reported that the use of multidimensional constellation signals can help to reduce the bit error rate in Additive Gaussian channels by using the hyperspace geometry more efficiently. Similarly, in fading channels, dimensionality provides an inherent signal space diversity (distinct components between two constellations points), so the amplitude degradation of the signal are combated significantly better. Moreover, the set of n-dimensional signals also provides great compatibility with various Trellis Coded modulation schemes: N-dimensional signaling joined with a convolutional encoder uses fewer redundant bits for each 2D signaling interval, and increases intra-subset minimum squared Euclidean distance (MSED) to approach the ultimate capacity limit predicted by Shannon's theory. The multidimensional signals perform better for the same complexity than two-dimensional schemes. The inherent constellation expansion penalty factor paid for using classical mapping structures can be decreased by enlarging the constellation's dimension. In this thesis, a multidimensional signal set construction paradigm that completely avoids the constellation expansion penalty is used in Band-limited channels and in fading channels. As such, theoretical work on performance analysis and computer simulations for Quadrature-Quadrature Phase Shift Keying (Q2PSK), Constant Envelope (CE) Q2PSK, and trellis-coded 16D CEQ2PSK in ideal band-limited channels of various bandwidths is presented along with a novel discussion on visualization techniques for 4D Quadrature-Quadrature Phase Shift Keying (Q2PSK), Saha's Constant Envelope (CE) Q2PSK, and Cartwright's CEQ2PSK in ideal band-limited channels. Furthermore, a metric designed to be used in fading channels, with Hamming Distance (HD) as a primary concern and Euclidean distance (ED) as secondary is also introduced. Simulation results show that the 16D TCM CEQ2PSK system performs well in channels with AWGN and fading, even with the simplest convolutional encoder tested; achievable coding gains using 16-D CEQ2PSK Expanded TCM schemes under various conditions are finally reported.

As moscas-das-frutas (Diptera: Tephritidae) são as principais pragas da fruticultura no mundo, pelos danos que ocasionam diretamente e indiretamente e pela facilidade de adaptação. O manejo das moscas-das-frutas através do monitoramento da população com diferentes substâncias atrativas mais eficientes é de suma importância. Assim, o objetivo com este trabalho foi avaliar a eficiência da inclusão do acetato de amônia em diferentes concentrações nas soluções compostas de proteína hidrolisada de milho e açúcares. O experimento 1 foi realizado em pomar de goiaba durante 7 semanas e avaliadas 6 soluções atrativas: Isca Samaritá® Tradicional (5%), Isca Samaritá® Tradicional + 3% de acetato de amônia (5% + 3%), Isca Samaritá® Tradicional + 5% de acetato de amônia (5% + 5%), Isca Samaritá® Tradicional + 7% de acetato de amônia (5% + 7%), Melaço (7%) e pastilhas de torula (1%). O delineamento experimental utilizado foi o casualizado em blocos com 6 tratamentos e 4 repetições. As armadilhas utilizadas foram do tipo McPhail. As trocas eram feitas a cada 7 dias. Não houve diferença para o total de moscas-das-frutas capturadas pelas soluções de torula e Isca Samaritá® Tradicional + 3% e 7% de acetato de amônia, sendo as mais atrativas. Também não houve diferença na captura de fêmeas de moscas-das-frutas para os atrativos torula e Isca Samaritá® Tradicional + 3% de acetato de amônia. Para insetos úteis e inimigos naturais as soluções com melaço e torula foram as menos seletivas. Com a adição de acetato de amônia foi possível verificar um aumento considerável na atratividade em relação ao produto comercial, principalmente no primeiro dia após a instalação no campo. A solução Isca Samaritá® Tradicional + 3% de Acetato de Amônia foi selecionada como o atrativo com melhor custo/benefício com adição de acetato de amônia testado e avaliado a eficiência da atratividade no experimento 2 comparando com Isca Samaritá® Tradicional (5%), Melaço (7%) e pastilhas de torula (1%). Utilizou-se a metodologia de marcação-liberação-recaptura de A. fraterculus estéreis. A dispersão foi monitorada a partir de um ponto central de liberação nas direções cardeais e colaterais utilizando armadilhas McPhail. A direção de dispersão através da análise circular exposta pelo Rose Diagram, identificou que as maiores frequências de recaptura foram nas posições onde se encontravam a torula e a Isca Samaritá® Tradicional + 3% de acetato de amônia. / The fruit flies (Diptera: Tephritidae) are the main pests of fruit crops in the world, due to the direct and indirect damage that its causes and easy of adaptation. The management of the fruit flies through population monitoring with different attractive substances more efficient is very important. The objective with this study was to evaluate the efficiency of the inclusion of ammonium acetate at different concentrations in the solutions composed of corn hydrolysed protein and sugars. The experiment 1 was conducted in guava orchard during seven weeks and evaluated 6 attractives solutions: Isca Samaritá® Traditional (5%), Isca Samaritá® Traditional + 3% ammonium acetate (5% + 3%), Isca Samaritá® Traditional + 5% ammonium acetate (5% + 5%), Isca Samaritá® Traditional + 7% of ammonium acetate (5% + 7%), molasses (7%) and torula pellets (1%). The experimental design was a randomized block with 6 treatments and 4 repetitions. The traps used were of the McPhail type. Exchanges were make every 7 days. There was not difference for the total the fruit flies captured by torula solutions and Isca Samaritá® Traditional + 3% and 7% of ammonium acetate, the most attractive. There was not difference in female fruit flies captured by torula solutions and Isca Samaritá® Traditional + 3% ammonium acetate. For social insects and natural enemy the solutions with molasses and torula were less selective. With the addition of ammonium acetate it was possible to see a considerable increase in attractiveness to the commercial product, especially on the first day after installation in the field. The solution Isca Samaritá® Traditional + 3% Ammonium Acetate was selected as the best cost benefit with the addition of ammonium acetate tested and evaluated the attractiveness of efficiency in experiment 2 compared to Isca Samaritá® Traditional (5%), molasses (7%) and torula pellets (1%). It used the methodology of mark-release-recapture A. fraterculus sterile. The dispersion was monitored from a central point of release and the side cardinal directions, in McPhail traps. The direction of dispersion through the circular analysis exposed by Rose Diagram identified that the greatest frequency of recaptures were in positions where they were the torula and Isca Samaritá® Traditional + 3% ammonium acetate.

Object-oriented analysis and design approach has become the mainstream of today¡¦s systems development technique. The Timing Diagram and State Machine Diagram from the Unified Modeling Language (UML) are becoming the major tools for modeling the platform independent model (PIM) of an embedded system. Once these two diagrams are constructed, the results can then be transformed into its platform specific model and template code based on the model driven architecture (MDA) approach. However, the detailed guideline for the transformation from Timing Diagram and State Machine Diagram to the template code is lacking. Therefore, this study presents a methodology which provides guidelines for the transformation from State Machine Diagram and Timing Diagram to template code for the embedded system. The research methodology is articulated using the design science research methodology. A usability evaluation with a real-world embedded system case is performed to demonstrate its applicability. The results indicated that with this proposed method, the system developer can effectively transform the PIM of an embedded system into its template code.

The last decade of the 20th century witnessed a revival of interest in the idea of diagrams in many disciplines, including architecture. Thus, terms like &#039 / diagram architecture&#039 / and &#039 / diagrammatic practice&#039 / have started to dominate the architectural discourse, both in theory and practice. Although much of the contemporary work examined under the rubric &#039 / diagram architecture&#039 / celebrate diagram&#039 / s capacity to generate new ideas and forms and embrace the diagram as a tool to revolt against the authority of established architectural traditions (such as design and planning methods, typological solutions), this study, in a critical attempt, underlines diagram&#039 / s role as a mnemonic tool mediating what the architectural history and tradition hand down to us. While the significance of diagram&#039 / s share in the generative activities of architectural design is acknowledged, it is proposed that diagram&#039 / s role as an antidote for precedence is overemphasized and misleading, and that its repetitive character in form generating procedures through the study of architectural precedents should come under scrutiny as well. To achieve a better understanding of the mediating role of diagrams as mnemonic tools in architectural design, this study presents a comparative analysis of Le Corbusier&#039 / s Villa Savoye and Rem Koolhaas&#039 / Maison a Bordeaux. The idea of this comparison is borrowed from Anthony Vidler and its model is an adaptation based on the comparative formal analysis employed by Colin Rowe in his seminal &quot / Mathematics of the Ideal Villa&quot / to compare Palladio&#039 / s Villa Malcontenta and Le Corbusier&#039 / s Villa Stein. Rather than an exhaustive diagrammatic analysis, the comparison is instrumentalized to initiate a dialogue between the two buildings in an attempt to highlight the relation between architectural precedents and diagrams. The study also aims to cast light on the issues related with the contemporary architectural discourse of diagrams.