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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analysis of a Split-Path Gear Train with Fluid-Film Bearings

Wolff, Andrew Vincent 13 May 2004 (has links)
In the current literature, split path gear trains are analyzed for use in helicopter transmissions and marine gearboxes. The goal in these systems is to equalize the torque in each path as much as possible. There are other gear trains where the operator intends to hold the torque split unevenly. This allows for control over the gearbox bearing loading which in turn has a direct effect on bearing stiffness and damping characteristics. Having control over these characteristics is a benefit to a designer or operator concerned with suppressing machine vibration. This thesis presents an analytical method for analyzing the torque in split path gear trains. A computer program was developed that computes the bearing loads in various gearbox arrangements using the torque information gathered by the analytical method. A case study is presented that demonstrates the significance of the analytical method in troubleshooting an industrial gearbox that has excessive vibration. / Master of Science
2

A comparison of a Klockenburg style split keyboard and a standard PC keyboard on typing speed and posture

Austin, Henry Eitt 25 April 2007 (has links)
The current study compares biomechanical and productivity outcomes related to the use of a Klockenburg (split and angled) style keyboard as opposed to the use of a standard PC 101 style keyboard among office workers. The study used 10 subjects (5 male and 5 female) who were employees of a large insurance company. Subjects were categorized by job classification, including 5 exempt and 5 nonexempt employees. Each subject was evaluated on both of the keyboards in a laboratory setting after three weeks of familiarization with the keyboards at their workstation. Productivity was measured as words per minute. In the lab, biomechanical outcomes included angular measures of forearm pronation/supination, wrist flexion/extension, wrist radial/ulnar deviation and neck angle. Lab results showed that the Klockenburg keyboard negatively impacted productivity and neck posture, while forearm pronation/supination and wrist radial/ulnar deviation were in more neutral positions. There was no significant difference in wrist extension between the two keyboards. In the field, the Klockenburg keyboard did not impact productivity.
3

Components of variance estimation for the split-plot design

Li, Shou-hua, January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
4

Účetní a daňové aspekty při fúzích a rozdělování obchodních společností

Petruchová, Kateřina January 2011 (has links)
No description available.
5

What You Need to Know Before You Buy Your “Ranchette”— Lot-Splits Versus Subdivisions in Rural Arizona

Apel, Mark 10 1900 (has links)
4 pp. / Originally published 2/2011. / Arizona's rural areas are dotted with small acreage properties that are too big to mow and too small to farm. This fact sheet describes the legal processes that create these kinds of properties and inform the reader on the difference between lot-split properties and those that undergo a legal subdivision process with a local county government. Revised 9/2016; Originally published 2/2011.
6

Otimização de misturas quimicas com flexibilidade na ordem de execução dos experimentos / Chemical mixture optimization with flexibility in the execution order of experiments

Borges, Cleber Nogueira 10 May 2007 (has links)
Orientador: Roy Edward Bruns / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-09T12:52:19Z (GMT). No. of bitstreams: 1 Borges_CleberNogueira_D.pdf: 1328148 bytes, checksum: ba185b4a95590eaf4f5554aed4c37d81 (MD5) Previous issue date: 2007 / esumo: Neste trabalho é apresentado o planejamento estatístico split-plot onde as unidades main-plots e sub-plots são planejamentos de misturas químicas. Main-plots e sub-plots são definidos de acordo com a estrutura simplex-centróide. O planejamento foi aplicado para a otimização simultânea de solventes extratores e fases móveis utilizados na separação cromatográfica de compostos químicos de plantas. O interesse foi determinar os melhores valores das respostas (maiores números de picos) em função dos extratores e fases móveis. A vantagem da blocagem dos experimentos segundo a estrutura split-plot é a conveniência por minimizar (ou facilitar) o trabalho experimental ou reduzir resíduos químicos ou ambos. A desvantagem é que o tratamento estatístico de tal sistema se torna mais complexo que os planejamentos com esquemas aleatórios. Gráficos normais foram utilizados para a escolha de modelos e assim, evitando a realização de replicatas dos experimentos / Abstract: A split-plot statistical design is proposed for which the main-plots and sub-plots are both chemical mixture designs. Main-plots and sub-plots are investigated using the simplex-centroid design. The composite mixture-mixture design was applied to the simultaneous optimization of extractor solvents and mobile phases used in the chromatographic separation of chemical compounds from plant materials. The main goal was to determine the best response values, largest number of peaks, as a function of the extractor and mobiles phase components. The advantages of using blocked experiments following the split-plot structure is to minimize (or facilitate) the experimental work as well as reduce the chemical residuals that must be discarded or both. The drawback is that the statistical treatment of the system becomes more complex than designs with random schemes. Normals graphs were utilized for choosing models so, the realization of replicate experiments could be avoided. / Doutorado / Quimica Analitica / Doutor em Ciências
7

Modélisation et simulation des splits dans les structures composites stratifiées / Splits modelling and computation in laminated composite structures

Bainier, Hadrien 20 December 2018 (has links)
Le design de pièces de structures aéronautiques en matériau composite requiert un grand nombre de tests et de simulations à différentes échelles. Dans ce contexte industriel, les modèles de comportement sont amenés à prendre une importance de plus en plus prégnante. L'idée développée dans cette thèse est d'améliorer la description de la fissuration transverse à travers le mésomodèle des composites, introduit au LMT dans les années 80. L'objectif est d'être en mesure de prédire précisément par la simulation la rupture d'un stratifié, en conservant des coûts de calculs raisonnables en vue de substituer à tout ou partie des essais mécaniques onéreux. On propose ainsi une nouvelle version de notre modèle qui combine, à la fois la prise en compte de la fissuration transverse localisée sous forme de split, et une description homogénéisée pour les fortes densités de fissures transverses. Afin de concilier ces deux approches un critère de détection ad hoc est proposé, le cas échéant les macrofissures sont introduites dans le modèle par le biais d'éléments cohésifs.Une partie de l'originalité de ce travail est de concevoir et développer des méthodes de calculs, en vue de leur transfert vers l'industrie. Pour assurer la pérennité des développements, et pouvoir traiter des problèmes industriels (grand nombre de degrés de liberté, géométries industrielles) on utilise uniquement des logiciels de calculs commerciaux. `A cette fin, l'ensemble des développement a été implémenté de manière non intrusive sous SAMCEF. Enfin, pour éprouver la nouvelle stratégie proposée, une campagne de validation en partenariat avec AIRBUS GROUP INNOVATION a été menée sur des structures en matériau composites stratifiées formées selon des empilements complexes et présentant des accidents géométriques. Le développement de lois de comportements adoucissantes entraîne des problèmes de dépendance au maillage, la question de la localisation est alors abordée sous un angle pratique. / Structural aerospace parts design in composite material requires a large number of tests and simulations at different scales. In this industrial context, constitutive laws are more and more important.The idea of this thesis is to improve the description of transverse cracking in the composite mesomodel, introduced in the LMT during the 80's. The objective is to be able to predict accurately the failure of a laminated composite structure, at cheap computational cost, in order to replace some of expensive mechanical tests.We propose a new version of our model which combine, isolated transverse cracks description such as splits, and an homogenized representation to model important transverse cracks density. To reconcile these two approcahes an ad hoc criterion is introduced, if necessary macrocracks are set in the model by using cohesive elements. A significant proportion of this works is to design and elaborate methods and computation strategy, in order to transfer from academic world to industry. To maintain computer code, and be able to compute industrial mechanical problems (large number of DOF, complex geometry) only commercial softwares must be used. For this purpose, the whole code is implemented in a non intrusive way on SAMCEF software. Finally, to challenge the new strategy, a campaign of validation, with our industrial partner AIRBUS GROUP INNOVATION was carried about structures in laminated composite material, with complex stackings with stress concentrations. Constitutive laws with softening triggers off mesh dependance issues, then the question of localization is discussed from a practical angle.
8

Best-first Decision Tree Learning

Shi, Haijian January 2007 (has links)
In best-first top-down induction of decision trees, the best split is added in each step (e.g. the split that maximally reduces the Gini index). This is in contrast to the standard depth-first traversal of a tree. The resulting tree will be the same, just how it is built is different. The objective of this project is to investigate whether it is possible to determine an appropriate tree size on practical datasets by combining best-first decision tree growth with cross-validation-based selection of the number of expansions that are performed. Pre-pruning, post-pruning, CART-pruning can be performed this way to compare.
9

Determining Reliability Of The PEAK Assessment Tool Using Split Half Reliability

Mason, Haley Alissa 01 December 2015 (has links)
The present study looked at the internal reliability of the PEAK Relational Training Assessment, using a split-half method of measurement. The reliability of the assessment questions within each of the four factors, within the PEAK Relational Training Assessment was estimated through this process. Eighteen participants, between the ages of 26 months and ten years old were included in the study. All participants had been diagnosed with either a language based or developmental disability, including autism, seizure disorder, Down syndrome and related language disorders. The PEAK Relational Training Assessment (PEAK-D) was administered by a direct-care provider for each of the 18 participants and during standard instructional periods. Results indicate that for each of the 18 participants, there was a strong correlation between scores when one half of the items in each factor were compared to the remaining half. Results did show internal reliability for the PEAK-D when using split-half methodology.
10

The Effect of Stock Splits on Small, Medium, and Large-sized Firms Before and After Decimalization

Jang, Seon Deog 12 1900 (has links)
This study examines the impact of reducing tick size and, in particular decimalization on stock splits. Based on previous studies, this study examines hypotheses in the following three areas: first, market reaction around stock split announcement and ex-dates, second, the effect of tick size on liquidity after stock split ex-dates, and third, the effect of tick size on return volatility after stock split ex-dates. The impact of tick size on market reaction around split announcement and ex-dates is measured by abnormal returns and buy and hold abnormal returns (BHARs). Also, this study investigates the long term impact of decimalization on market reaction for small, medium, and large firms for the three different tick size periods. The effect of tick size on liquidity after stock split ex-dates is measured by turnover, relative bid ask spread, and market maker count. The effect of tick size on return volatility around stock split announcement and ex-dates is measured by return standard deviation. Also, this study investigates the long term impact of decimalization on volatility after split ex-dates for small, medium, and large firms for three different tick size periods.

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