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"Sobre a existência de pontos periódicos para homeomorfismos do anel fechado" / "On the existence of periodic points for homeomorphisms of the closed annulus"Walter Teofilo Huaraca Vargas 20 July 2006 (has links)
O conhecido Teorema de Poincaré afirma: O número de rotação de homeomorfismo do círculo S^1 que preserva orientação é racional se, e somente se, o homeomorfismo possui um ponto periódico cujo período é igual ao denominador de tal racional. Na presente dissertação estudamos resultados análogos, ao resultado acima mencionado, para homeomorfismos do anel A=S^1 x I homotópicos à identidade. Mais precisamente, estudaremos o famoso Teorema de Poincaré - Birkhoff e algumas versões devidas a J. Franks. Isto será feito impondo algumas condições no conjunto de rotação, o qual é uma generalização do número de rotação para homeomorfismos do círculo. / The well known Poincaré's Theorem state: The rotation number of an orientation preserving circle homeomorphism is rational if, only if, the homeomorphism has a periodic point of period equal to denominator of the rational. In this monograph we study results analogous, to the result above mentioned, for homeomorphisms of A=S^1 x I homotophics to the identity. More precisely, we study the famous Poincaré - Birkhoff Theorem and some versions obtained by J. Franks. This it will be done imposing some conditions in the rotation set, which is generalization of the rotation number for circle homeomorphisms.
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The significance of embrasure design on the fracture load of fixed denture prosthesis: an in vitro studyAlbar, Nasreen Hassan 09 January 2019 (has links)
OBJECTIVE: This study evaluated two embrasure designs by measuring their differential effect on load at failure of provisional fixed partial dentures (FPDs) fabricated of five commercially available polymer-based restorative materials.
METHODS: Five provisional C&B materials were selected to fabricate FPDs with two different embrasure designs: sharp vs. rounded embrasures (n=12 for each material). The test materials included: Telio CAD (Ivoclar-Vivadent), Coldpac (Motloid), Protemp Plus (3M), VersaTemp (Sultan), and Turbo Temp (Danville). The embrasures were formed using prefabricated cutters with measured Radii (0.002r and 0.03r) and a fixture to hold each provisional FPD in place for the uniform standardized cuts. Molds for the CAD/CAM provisional FPDs were used to fabricate the syringeable temporary materials and form bridges with the same geometric design. All provisional bridges were cemented using Temp-Bond (Kerr) to the corresponding standardized abutments and tested to failure in a universal Instron testing machine by loading each specimen compressively in the mid pontic region. The load at break was recorded in Newton. A one-way analysis of variance (ANOVA) was used to compare the difference in each group’s mean.
RESULTS: A significant difference in fracture load was found between the two groups of designs, in which the round embrasure was significantly stronger than was the sharp. A significant difference also was found between the type of temporary material used to fabricate the bridge in the two groups, and except for Coldpac, no significant difference between the embrasure anatomies was found. Fatigue loading did not appear to influence the two bridges’ fracture load, but it did show a significant difference with respect to the modulus of elasticity, in that the bridges that underwent fatigue loading showed a higher elastic modulus by comparison to the control group. Another variable that influenced the modulus of elasticity was the type of temporary material used to fabricate the bridge, in which TelioCAD was found to be the stiffest. However, the embrasure design did not seem to affect the bridges’ rigidity.
CONCLUSION: A significant difference was found in fracture strength between the rounded and sharp embrasure design. Except for Coldpac, the rounded embrasure showed higher fracture toughness than did the sharp. No significant correlation was found between the two embrasure designs and the modulus of elasticity. Interestingly, the fatigued bridges that underwent cyclic loading showed a higher modulus of elasticity. The sharp embrasure design showed no fracture in the pontic region, while the rounded design did in 5.47% of the sample. This may be explained by the photoelastic bridges, in which the stress diffuses in the rounded design to include the pontic region, while in the sharp design, the stress is concentrated on the connector area. Stress analysis, both by means of photoelastic and finite element analysis, demonstrated that the bridge with the sharp embrasure design’s stress was high in the connector area compared to the round embrasure design.
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Fed fund target model in presence of unspanned stochastic volatility.January 2008 (has links)
Lai, Kwok Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 64-66). / Abstracts in English and Chinese. / Abstract --- p.i / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Literature Review --- p.9 / Chapter 3 --- Preliminary Analysis of Data --- p.17 / Chapter 3.1 --- Data --- p.17 / Chapter 3.2 --- Preliminary Analysis of Unspanned Stochastic Volatility --- p.20 / Chapter 4 --- A Jump-Diffusion Model for Federal Funds Target Rate --- p.23 / Chapter 4.1 --- Model Specification --- p.23 / Chapter 4.2 --- Estimation Result --- p.31 / Chapter 5 --- Pricing and Hedging Performance of Interest Rate Derivatives --- p.34 / Chapter 5.1 --- Pricing Performance of Interest Rate Cap --- p.34 / Chapter 5.2 --- Hedging Performance of Interest Rate Caplet --- p.38 / Chapter 5.3 --- Hedging Performance of Interest Rate Straddle --- p.42 / Chapter 6 --- Conclusion --- p.49 / Figures --- p.51 / Tables --- p.55 / Bibliography --- p.64
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Impacto dos radares fixos na velocidade e na acidentalidade em trecho da rodovia Washington Luís / Impact of thefFixed radars in thesSpeed and the analysis of accidents in segment of the Washington Luis highwayYamada, Mario Guissu 15 December 2005 (has links)
Neste trabalho é avaliado o impacto do emprego de radares fixos na velocidade e na acidentalidade no trecho compreendido entre o Km 153,350 e o Km 227,800 da Rodovia Washington Luís - SP-310 (extensão de 74,450 km), localizado no interior do estado de São Paulo e cuja concessão pertence à empresa Centrovias. A avaliação do impacto na velocidade e na acidentalidade foi realizada em segmentos curtos situados no entorno dos radares e em toda a extensão do trecho. As medições de velocidade foram realizadas nos pontos onde se localizam os radares fixos, em pontos próximos (cerca de 2km antes e 2km depois) e em pontos distantes. Os resultados mostram que o limite legal de velocidade é mais respeitado no local onde se localizam os radares e um pouco antes dos mesmos. Logo depois dos radares e em pontos distantes, o limite máximo de velocidade é muito menos respeitado. É muito alta a porcentagem de veículos que passam pelos radares com velocidade acima do limite legal mais a tolerância de 7km/h (8,4%), e que, portanto, cometem infração e deveriam ser multados. Claramente, a abrangência espacial dos radares fixos no sentido de reduzir as velocidades é limitada a um pequeno segmento localizado, na sua maior parte, imediatamente antes dos mesmos. A evolução dos índices de acidentes mostra que não houve melhoria na segurança com a colocação dos radares nos segmentos localizados no entorno dos mesmos. Praticamente todos os índices apresentaram crescimento. Isso também acontece quando se analisa a evolução dos índices de acidentes ao longo de toda a extensão do trecho de rodovia estudado, pois todos os índices experimentaram crescimento / In this work the impact of the use of fixed radars in the speed and in the analysis of accidents in the segment between the Km 153,350 and the km 227,800 of the Washington Luís Highway is evaluated - SP-310 (extension of 74,450 km), located in the interior of the state of São Paulo and whose concession belongs to the Centrovias company. The evaluation of the impact in the speed and in the analysis of accidents was carried out in short segments situated around of the radars and in all the extension of the segment. The measurements of speed had been done in the points where the fixed radars were located, in points near (about of 2km before and 2km after) and in distant points. The results show that the legal limit of speed is more respected in the place where the radars are located and just before them. Soon after the radars and in distant points, the maximum limit of speed is much less respected. The percentage of vehicles that pass by the radars with speed above of the legal limit plus the tolerance of 7km/h (8,4%), is very high, resulting in infraction that should be fined. Clearly, the use of the fixed radars intending to reduce the speeds is limited to a small segment located, normally immediately before them. The evolution of the indices of accidents shows that did not have improvement in the security using radars in the segments located near them. Practically all the indices had presented growth. This also happens when it is analyzed the evolution of the indices of accidents in all the extension of the studied segment of highway, because all the indices had growth
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Combinatorial Proofs of Generalizations of Sperner's LemmaPeterson, Elisha 01 May 2000 (has links)
In this thesis, we provide constructive proofs of serveral generalizations of Sperner's Lemma, a combinatorial result which is equivalent to the Brouwer Fixed Point Theorem. This lemma makes a statement about the number of a certain type of simplices in the triangulation of a simplex with a special labeling. We prove generalizations for polytopes with simplicial facets, for arbitrary 3-polytopes, and for polygons. We introduce a labeled graph which we call a nerve graph to prove these results. We also suggest a possible non-constructive proof for a polytopal generalization.
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Minimax v úlohách rozvrhování za nejistoty / Minimax in scheduling problems under uncertaintyJeliga, Jan January 2019 (has links)
In this work, we deal with fixed interval scheduling problems with the possibility of random delay of the end of the tasks (FIS). First, we pre- sent the basic deterministic FIS problems and ways to solve them. Next, we introduce the concept of minimax and present two well-known and one new FIS problem under uncertainty, when random task delays are conside- red to belong to a certain uncertainty set. Next, we deal with the solution of previously presented FIS problems for five chosen uncertainty sets. We present both previously achieved and original results. The work concludes with a summary of a numerical study of two problems. First, we explore the possibility of Lagrange relaxation application to the first presented problem. Next we explore the quality of approximation allowing to solve the later of problems as LP. 1
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Flexural strength of interim fixed prosthesis materials after simulated functionHeying, Jamie John 01 December 2009 (has links)
Statement of Problem
There are limited studies evaluating the effect of a cyclic load on interim fixed prosthetic materials and its effect on flexural strength.
Purpose of Study
1) To verify the flexural strength of previously studied interim fixed prosthetic materials.
2) To establish the flexural strength of new, advanced generation and untested interim fixed prosthetic materials.
3) To determine the effect of cyclic load on the flexural strength of interim fixed prosthetic materials.
Materials and Methods
Bar-type specimens of Caulk Temporary Bridge Resin, VitaVM CC, Protemp 3 Garant and Radica were fabricated according to International Standards Organization 4049 and American National Standards Institute/American Dental Association specification 27. After being stored in distilled water for 10 days, specimens were divided into Noncycled and Cycled Groups. The Noncycled Group specimens were fractured under a 3-point loading in a Bose Electroforce 3300 testing instrument at a crosshead speed of 0.75 mm/min. Cycled Groups specimens underwent a 6-12 Newton 3 Hertz cyclic load for 20,000 cycles in a Bose Electroforce 3300 testing instrument. Immediately following completion of the cycles, the specimens were fractured under a 3-point loading. Maximal loads to fracture in Newtons were recorded and mean flexural strengths were calculated (n = 20 per group). Comparisons were made with analysis of variance and Tukey's Multiple Comparison Test.
Results
Noncycled (NC) and Cycled (C) groups order of mean flexural strengths (MPa) from lowest to highest mean were as follows: Caulk (Noncycled - 53.83; C - 60.02), Vita VM CC (NC - 65.96; C - 66.83), Protemp 3 Garant (NC - 75.85; C - 77.18), and Radica (NC - 106.1; C - 115.96). In the Noncycled and Cycled groups, Radica was statistically superior when compared to all materials and Protemp 3 Garant was statistically superior to Caulk Temporary Bridge Resin. There was no statistically significant difference between the material's flexural strengths before and after cycles.
Conclusion
Within the limitations of this study, 20,000 cyclic loads of 6-12 Newtons at 3 Hertz did not have a significant effect on the flexural strength of interim fixed prosthetic materials. Radica demonstrated significantly superior flexural strength over other materials tested.
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Priming and the Post-Prime Pause in Mixed Fixed-Ratio SchedulesAlferink, Larry Allen 01 May 1975 (has links)
The present study was designed to investigate the effects of a stimulus change inserted in the large component of a mixed fixed-ratio 10 fixed-ratio 100 schedule. In mixed fixed-ratio schedules, a run of responses which approximates the response requirement of the smaller fixed ratio occurs at the beginning of the larger fixed ratio. This run of responses and the pause it precedes is called a prime. In Experiment I, priming acquisition was compared in a mixed schedule in which a change in key-color followed completion of the first 10 responses of the fixed-ratio 100 component and a mixed schedule with no stimulus change. Primes were acquired more rapidly in the mixed schedule with the stimulus change and the number of responses in a priming run was less variable than occurred without the stimulus change. In Experiment II, the effect of the stimulus change on primes was further investigated by removal of the smaller fixed-ratio component or by varying the location of the stimulus change. Primes occurred only when the smaller fixed-ratio component was present. Varying the location of the stimulus change resulted in the transfer of control from the external stimulus to response-produced stimuli. Future investigation of this point of transfer should prove useful in the study of the proprioceptive stimulus control of homogeneous behavior sequences.
In Experiments Ill through VI, the variables controlling the length of the post-prime and the post-reinforcement pauses were investigated using the mixed FR x chained FR x FR y schedule. In this series of experiments, FR x was varied with FR y held constant at both high and low values. In addition, FR y was varied with FR x held constant at both high and low values. The results indicate that the post-prime pause is primarily a function of FR y, the number of responses required after the priming run. On the other hand, both post-reinforcement pauses were shown to be a function of FR x, the size of the small fixed ratio. An interaction between FR x and FR y and both the post-reinforcement and the post-prime pauses suggested that pausing in mixed schedules is a closed system. Taken as a whole, these results indicate the importance of mixed chained schedules in the investigation of the priming phenomenon.
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Effects of intermittent reinforcement upon fixed-ratio discriminationLydersen, Tore 01 May 1982 (has links)
Four pigeons had discrimination training that required the choice of a left side-key following completion of a fixed-ratio 10 an the center key, and a right side-key response after fixed-ratio 20. Correct choices were reinforced on various fixed-interval, fixed-ratio, random-interval, and random-ratio schedules. When accuracy was examined across quarters of intervals (fixed-interval schedules) or quarters of median interreinforcerrent intervals (fixed-ratio schedules), accuracy was usually laver in the second quarter than in the first, third, or fourth quarters. When accuracy was examined across quarters of ratios (fixed-ratio schedules) or quarters of median number of correct interreinforcement trials (fixed-interval schedules), accuracy increased across quarters. These accuracy patterns did not occur m random-interval or random-ratio schedules. The results indicate that, when choice patterns differed on fixed-interval and fixed-ratio schedules, these differences were due to the methods of data analyses.
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Evolución de las terminaciones en las preparaciones dentarias en Rehabilitación OralKawashima Matamoros, Luciana Sachie 14 December 2018 (has links)
El objetivo de esta revisión es reportar las técnicas paso a paso para realizar terminaciones dentarias correctas según el material para la confección de las prótesis fijas. / The aim of this review is to report on the techniques to perform corrected dental terminations according to the preparation material of fixed prostheses. / Tesis
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