1,333 research outputs found

    Diagnosis and Treatment of Insomnia

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    The Effects of Mathematics Placement on Successful Completion of an Engineering Degree and how One Student Beat the Odds

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    This dissertation comprises a sequential explanatory mixed methods study seeking to understand persistence in engineering based on a studentā€™s initial mathematics course and the experience of a student who began in the lowest level mathematics course and completed an engineering degree despite struggling in mathematics courses. The ļ¬rst phase of the quantitative piece examines one year retention rates for ļ¬rst year engineering students based on initial mathematics course. In the second quantitative phase a stepwise logistic regression model was conducted to determine what factors are related to engineering persistence. The third quantitative phase is a retrospective study to determine the initial mathematics course for graduating engineering students. The ļ¬nal phase of the quantitative piece examines graduation rates for ļ¬rst year engineering students based on initial mathematics course. Results of the ļ¬rst phase indicate engineering students starting in non-college level mathematics courses are signiļ¬cantly less likely to be retained in engineering a year after their ļ¬rst semester compared to students starting in one of the calculus courses. In the logistic regression model with initial math course, grade in the initial math course, gender and race as predictor variables, course, grade, and gender were found to signiļ¬cantly predict retention in engineering one year later. Results from the third phase indicate very few students graduating with an engineering degree start in precalculus. It also shows some engineering disciplines may be more attainable for students starting in non-college level mathematics courses, like precalculus. Results of graduation rates in the fourth quantitative phase conļ¬rm engineering students starting in precalculus are signiļ¬cantly less likely to graduate with an engineering degree than those starting in any higher level mathematics course. A case study was conducted to fully explain how a student persisted in engineering after starting in precalculus. One of the few students starting in precalculus who graduated with an engineering degree was interviewed to understand why he chose engineering, why he didnā€™t quit or change majors when he had to repeat calculus II multiple times, and how he was able to complete his calculus courses despite his mathematical deļ¬ciencies. Other individuals who he indicated were inļ¬‚uential in his success were also interviewed. A framework combining future time perspective and self-regulation was used to explain his experience and why he didnā€™t quit. Another framework on self-regulated learning strategies was used to explain how he was able to successfully complete calculus II. The case study studentā€™s dream of becoming a pilot in the Air Force and his ā€˜canā€™t quitā€™ attitude were the motivation for his persistence in engineering. An instruc-tor in the Mathematical Sciences Department and the instructorā€™s ability to model self-regulation strategies were instrumental in the studentā€™s eventual completion of an engineering degree. By understanding the experience of one of the few successful engi-neering students who started in a non-college level mathematics course, educators can better advise future students with similarly poor mathematics backgrounds

    Technology in Mathematics Education and Ti-Navigator in the Mathematics Classroom

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    Over the past couple of decades, several studies have shown that mathematics achievement in the U.S. is either stagnate or declining while achievement in mathematics education in other countries has been improving. The current state of mathematics achievement on our nation is particularly daunting at a time when knowledge of mathematics is becoming increasingly important to acquire quality jobs. Some researchers believe that the lack of mathematics achievement may negatively affect technological developments and the standard of living in the U.S. One particularly promising technique may be the infusion of technology into mathematics classrooms. The proper use of technology may help raise mathematics achievement and interest in mathematics. More specifically, graphing calculators and the TI-Navigator can be used by teachers to help show increased interest in mathematics subjects and increased conceptual understanding of the material. A PowerPoint presentation summarizing the importance of mathematics and STEM education in the U.S. was developed for this project. The PowerPoint also highlighted material from the creation of a 3 hour staff development introducing the TI-Navigator to mathematics and science teachers

    Oscillating Airfoil Velocity Field During Large Amplitude Dynamic Stall

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    The leading edge flow field of an airfoil executing a. sinusoidal oscillatory motion and experiencing dynamic stall under compressibility conditions has been studied using a two component LDV system. Phase averaged mean velocity measurements and some flow quantities derived from it are presented and discussed. The results indicate extremely large accelerations of the flow are present around the leading edge with mean velocity values 60% higher than and instantaneous velocities as large as 1. 75 times the free stream velocity. The velocity profiles at certain locations over the airfoil resemble that of a wake

    Vanden Bough, Mr and Mrs Oral History Interview: Class Projects

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    Preferred directions for resolving the non-uniqueness of Delaunay triangulations

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    AbstractThis note proposes a simple rule to determine a unique triangulation among all Delaunay triangulations of a planar point set, based on two preferred directions. We show that the triangulation can be generated by extending Lawson's edge-swapping algorithm and that point deletion is a local procedure. The rule can be implemented exactly when the points have integer coordinates and can be used to improve image compression methods

    Integrirano planiranje opskrbe električnom energijom, plinom i toplinskom energijom u općini

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    This paper presents the results of a case study to investigate different alternatives for the energy supply to a municipality on the western coast of Norway. The following alternatives for energy supply are modelled and analysed: i) a district heating system with three different heat centrals, ii) a natural gas distribution system and iii) a low temperature distribution system. The case study is performed with the optimization model "eTransport" developed for the planning of local energy systems where several alternative energy carriers and technologies are considered simultaneously. The model minimizes the total energy system cost of meeting the demands of electricity, heating, cooling and gas within a geographical area over a given planning horizon. The model uses a detailed network representation of infrastructures to consider investments in distributed central stations, components, cables and pipelines. The object function includes investments, operating and environmental costs.Ovaj članak prezentira rezultate analize slučaja koja istražuje razne alternative za opskrbu energije jedne općine na zapadnoj obali NorveÅ”ke. Sljedeće alternative za opskrbu energije su modelirane i analizirane: i) Područno grijanje s tri različite toplane ii) Distribucijski sustav za prirodni plin iii) Niskotemperaturni distribucijski sustav. Analiza slučaja je napravljena pomoću optimizacijskog modela ā€žeTransportā€œ razvijenog za planiranje lokalnih energetskih sustava s primjenom raznih nosioca energije i tehnologija. Model minimizira cijenu sustava koji zadovoljava potrebu za električnom i toplinskom energijom, hlađenjem i plinom u nekom geografskom području za vrijeme planiranja. Model koristi detaljnu reprezentaciju mrežne infrastrukture da uzme u obzir investiciju u toplane, komponente, troÅ”kove okoliÅ”a i operativne troÅ”kove

    Triangular mesh parameterization with trimmed surfaces

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    Given a 2manifold triangular mesh MāŠ‚R3M \subset {\mathbb {R}}^3, with border, a parameterization of MM is a FACE or trimmed surface F={S,L0,ā€¦,Lm}F=\{S,L_0,\ldots, L_m\} -- FF is a connected subset or region of a parametric surface SS, bounded by a set of LOOPs L0,ā€¦,LmL_0,\ldots ,L_m such that each LiāŠ‚SL_i \subset S is a closed 1manifold having no intersection with the other LjL_j LOOPs -- The parametric surface SS is a statistical fit of the mesh MM -- L0L_0 is the outermost LOOP bounding FF and LiL_i is the LOOP of the ith hole in FF (if any) -- The problem of parameterizing triangular meshes is relevant for reverse engineering, tool path planning, feature detection, redesign, etc -- Stateofart mesh procedures parameterize a rectangular mesh MM -- To improve such procedures, we report here the implementation of an algorithm which parameterizes meshes MM presenting holes and concavities -- We synthesize a parametric surface SāŠ‚R3S \subset {\mathbb {R}}^3 which approximates a superset of the mesh MM -- Then, we compute a set of LOOPs trimming SS, and therefore completing the FACE F=\ {S,L_0,\ldots ,L_m\} -- Our algorithm gives satisfactory results for MM having low Gaussian curvature (i.e., MM being quasi-developable or developable) -- This assumption is a reasonable one, since MM is the product of manifold segmentation preprocessing -- Our algorithm computes: (1) a manifold learning mapping Ļ•:Mā†’UāŠ‚R2\phi : M \rightarrow U \subset {\mathbb {R}}^2, (2) an inverse mapping S:WāŠ‚R2ā†’R3S: W \subset {\mathbb {R}}^2 \rightarrow {\mathbb {R}}^3, with \ (W\) being a rectangular grid containing and surpassing UU -- To compute Ļ•\phi we test IsoMap, Laplacian Eigenmaps and Hessian local linear embedding (best results with HLLE) -- For the back mapping (NURBS) SS the crucial step is to find a control polyhedron PP, which is an extrapolation of MM -- We calculate PP by extrapolating radial basis functions that interpolate points inside Ļ•(M)\phi (M) -- We successfully test our implementation with several datasets presenting concavities, holes, and are extremely nondevelopable -- Ongoing work is being devoted to manifold segmentation which facilitates mesh parameterizatio
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