This thesis compared tooth widths, arch widths, and arch lengths; their differences between males and females, and changes from early mixed dentitions to adult dentitions. Comparing subjects who were known to have Angle Class I normal occlusion in their permanent dentitions to subjects who were known to be Class I or Class II crowded malocclusions in their permanent dentitions. These comparisons can only be achieved utilizing data from a longitudinal study, such as the Iowa Growth Study. Dental casts in the early mixed dentition (average age of 8.85 years) and in the adult dentition (average age 15.45 years) taken from subjects who did not receive orthodontic treatment during or in the dates prior to data collection were measured for this study. The casts utilized were from the Iowa Growth Study; all of the subjects were of European descent. The longitudinal sample of casts in the Iowa Growth study were made from white dental stone poured into alginate impressions from 1946 until 1960. The objectives of this study were to compare individual tooth widths, mean sum tooth widths, arch widths, arch length segments, and arch perimeters of Class I Normal (CIN) and Class I and II crowded dentitions (CD) in the early mixed (MD) and permanent (PD) dentitions to explore new methods of predicting crowding. The goal was to evaluate the significance of differences between MD and PD for tooth widths, arch lengths, and arch widths in both arches of CIN and CD subjects to determine values that may be useful for MD space analysis. Thirty males and thirty females from the Iowa Growth Study with CIN and CD occlusions were selected from the longitudinal study. Casts of MD and PD subjects were double measured with digital calipers by both the primary and secondary investigators. The average of each investigator's two measurements were used to determine measurement error. All other statistical analysis was based on the mean measurements taken by CPW. Descriptive statistics were computed. The normal non-crowded and crowded samples were compared with two-sample t-test, and changes from MD to PD with paired-sample t-test. Examiner measurement errors were tested with intra-class correlation coefficients. When the mean sums of MD and PD tooth widths were compared, using data from all 60 subjects, the CD group had a significantly greater mean sum of tooth widths than the CIN group. In both genders, crowded dentitions had significantly greater mean sum of tooth widths than CIN's for both the maxilla and mandible in MD and PD. When the mean sums of the arch lengths [Perimeters] were compared using data from all 60 subjects, the arch perimeters of the CD and CIN samples did not differ. It was concluded that total arch lengths Perimeters] were not significant indicators for crowding. Gender comparisons: Within the CIN group, males had numerically larger tooth width sums and arch length sums than females. The sum of maxillary and mandibular tooth widths for CIN's and CD (both males and females) mandibular tooth widths for CIN's and CD (both males and females pooled together and sexes separately. In the MD stage the mean sum of maxillary and mandibular arch lengths in the MD were significantly greater than those in the PD, because arch perimeters decrease during the transition from mixed to permanent dentitions. In summary, the results of this research thesis study showed that the sum of tooth widths in both arches had a significant association with dental crowding. In contrast, the sum of arch lengths [perimeter in both arches] did not differ between the normal and crowded samples. Additional analysis of the measurements taken in this thesis research project, the individual arch length segments, especially the canine and posterior arch length segments in the right and left sides of the lower arch in the mixed dentition casts, and their relation to the sum of the widths of the lower permanent canines and premolars in the normal and crowded malocclusions may give us important information about the development of crowded malocclusions.

We develop an extension to the tactical planning model (TPM) for a job shop by the third author. The TPM is a discrete-time model in which all transitions occur at the start of each time period. The time period must be defined appropriately in order for the model to be meaningful. Each period must be short enough so that a job is unlikely to travel through more than one station in one period. At the same time, the time period needs to be long enough to justify the assumptions of continuous workflow and Markovian job movements. We build an extension to the TPM that overcomes this restriction of period sizing by permitting production control over shorter time intervals. We achieve this by deriving a continuous-time linear control rule for a single station. We then determine the first two moments of the production level and queue length for the workstation. / Singapore-MIT Alliance (SMA)

No description available.

Submitted by Clebson Anjos (clebson.leandro54@gmail.com) on 2015-05-19T19:15:23Z No. of bitstreams: 1 arquivototal.pdf: 3494677 bytes, checksum: 0878c999eeda11a6a563ac8d7e8a8e2f (MD5) / Approved for entry into archive by Clebson Anjos (clebson.leandro54@gmail.com) on 2015-05-19T19:15:44Z (GMT) No. of bitstreams: 1 arquivototal.pdf: 3494677 bytes, checksum: 0878c999eeda11a6a563ac8d7e8a8e2f (MD5) / Made available in DSpace on 2015-05-19T19:15:44Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3494677 bytes, checksum: 0878c999eeda11a6a563ac8d7e8a8e2f (MD5) Previous issue date: 2013-08-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we will make a brief study on the calculation of areas and lengths highlighting how these can be presented in high school, then we will use the di erential and integral calculus to extend the calculations of areas and lengths. Therefore, this study some of the developments in the history of calculus concepts and their "basic", beyond the definitions of areas, lengths, and applications of limit, derivative and integral. We emphasize that the provision contained in this learning material is not in a single textbook adopted in schools. / Neste trabalho faremos um breve estudo a respeito do cálculo de áreas e comprimentos destacando como esses podem ser apresentados no ensino médio, em seguida faremos uso do cálculo diferencial e integral para estendermos os cálculos de áreas e comprimentos. Para isso, estudaremos um pouco da evolução do cálculo na história e seus conceitos "básicos", além das definições de áreas, comprimentos, e aplicações do limite, derivada e integral. Ressaltamos que a disposição contida neste material didático não se encontra em um único livro didático adotado nas escolas.

O presente estudo buscou investigar se participantes videntes apresentaram a mesma performance nos julgamentos de comprimentos de linha do que participantes videntes vendados, cujas estimativas foram realizadas através da percepção tato-cinestésica háptica). Além disso, buscou-se conhecer se esta relação é mantida nas três diferentes formas de comprimentos de linha apresentados: reta, em L e curva e na utilização de dois métodos psicofísicos diferentes: estimação de magnitude e estimação de categoria. A amostra foi constituída por 120 participantes com visão normal, de ambos os sexos, com idade entre 18 e 35 anos, divididos em dois grupos de acordo com a modalidade sensorial: vidente e não vidente (vidente vendado). Os experimentos consistiram em: 1. estimação de magnitude visual; 2. estimação de magnitude não-visual; 3. estimação de categoria visual e 4. estimação de categoria não-visual. Trinta participantes se submeteram a cada um destes experimentos, divididos em três grupos de 10, de acordo com a forma dos comprimentos. Análises estatísticas permitiram concluir que: 1) comprimentos de linha diferentes foram percebidos como diferentes em todos os grupos; 2) a forma dos comprimentos de linha não interferiu nos julgamentos dos participantes; 3) a modalidade sensorial não interferiu nos julgamentos de comprimentos de linha dos participantes e 4) a relação entre o comprimento físico e a estimativa foi mantida em ambos os métodos utilizados, estimação de magnitude e estimação de categoria. / The present study aimed to investigate if sighted participants presented the same performance in the judgements of length of line as blindfolded sighted participants, whose estimates were performed through the touch-cinestesic (haptic) perception. Besides, it aimed to know if this relation is kept in the three different shapes of line length presented: straight; L-shaped and curved and in the use of two different psychophysics methods: magnitude estimation and category estimation. The sample was composed by 120 participants with normal sight, of both sexes, aged between 18 and 35, divided into two groups according to the sensorial mode: sighted participants and blindfolded sighted participants. The experiments consisted in: 1. visual magnitude estimation; 2. non-visual magnitude estimation; 3. visual category estimation and 4. non-visual category estimation. Thirty participants were submitted to each of them, divided into three groups of ten, according to the shape of the lengths. Statistic analysis allowed to conclude that: 1) different line lengths were perceived different in all the groups; 2) the shape of the line lengths did not interfere in the judgements of the participants; 3) the sensorial mode did not interfere in the participants’ judgements of line lengths; 4) the relation between physical length and estimate was kept in the use of both methods: magnitude estimation and category estimation.

Evaporated thin film sandwich structures of Au-SiOX-Au have been studied. These normally show electroforming effects and subsequently electron emission, electroluminescence, negative resistance and thermal-voltage memory effects. Previous work in the field is critically reviewed. It was shown that the time dependence of the device current and emission current can be explained by making certain modifications to the filamentary conduction theory of Dearnaley. Detailed direct current-voltage measurements have revealed the existence of two different types of breakdown behaviour. At voltages less than 20 V single-hole breakdowns were observed, while in the voltage range 20-30 V large scale irreversible breakdown behaviour took place. The dependence of the voltage at which this occurs (Vß) on insulator thickness and temperature, together with measurements of the device temperature at breakdown and visual evidence of damage after breakdown, has led to the conclusion that this type of breakdown is a thermal effect. Such measurements also pointed to the existence of a high field region within the insulator, and potential distribution measurements confirmed this hypothesis. The high field region was also in evidence at low temperatures where the device current (Ic) showed a log Ic α Vb1/2 dependence on applied voltage (Vb). Measurements of electron attenuation lengths in SiOx gave values of 400-1000 Å irrespective of temperature. The temperature independence was consistent with the emitted electron energy distributions at 77 and 300 K. It was shown that electrons underwent Bragg diffraction through the top Au electrode. The angular distribution of emitted electrons became more isotropic with increasing voltage. Measurements on other systems showed that Al-SiOx/B2O3-Al devices could withstand very high voltages and give improved emission efficiency, while Au-CaBr2-Au and Au-Si3N4-Au devices showed very high initial currents and current-voltage characteristics which were irreversible.

This study analyzed the relationships present between grip strength, wrist flexion, arm length, partial and total, and throwing velocity. Thirty-one subjects were tested to obtain the data on these variables. A multiple linear regression equation produced a significant F ratio for the relationship between grip strength and throwing velocity. Neither wrist flexion nor arm length obtained a significant F ratio to throwing velocity. A stepwise multiple regression equation again displayed a significant F ratio for grip strength and throwing velocity. Wrist flexion and arm length did not produce a significant F ratio for their relationships to throwing velocity. This study concludes that of the variables tested, only grip strength displayed a significant relationship to throwing velocity. This study indicates that throwing velocity can be predicted at a moderate level from the measurement of grip strength.

No description available.

Scheduling policies adopted for statistical multiplexing should provide delay differentiation between different traffic classes, where each class represents an aggregate traffic of individual applications having same target-queueing-delay requirements. We propose scheduling to optimally balance weighted mean instanteneous queue lengths and later weighted mean cumulative queue lengths as an approach to delay differentiation, where the class weights are set inversely proportional to the respective products of target delays and packet arrival rates. In particular, we assume a discrete-time, two-class, single-server queueing model with unit service time per packet and provide mathematical frame-work throughout our work. For iid Bernoulli packet arrivals, using a step-wise cost-dominance analytical approach using instantaneous queue lengths alone, for a class of one-stage cost functions not necessarily convex, we find the structure of the total-cost optimal policies for a part of the state space. We then consider two particular one-stage cost functions for finding two scheduling policies that are total-cost optimal for the whole state-space. The policy for the absolute weighted difference cost function minimizes the stationary mean, and the policy for the weighted sum-of-square cost function minimizes the stationary second-order moment, of the absolute value of the weighted difference of queue lengths. For the case of weighted sum-of-square cost function, the ‘iid Bernoulli arrivals’ assumption can be relaxed to either ‘iid arrivals with general batch sizes’ or to ‘Markovian zero-one arrivals’ for all of the state space, but for the linear switching curve. We then show that the average cost, starting from any initial state, exists, and is finite for every stationary work-conserving policy for our choices of the one-stage cost-function. This is shown for arbitrary number of class queues and for any i.i.d. batch arrival processes with finite appropriate moments. We then use cumulative queue lengths information in the one-step cost function of the optimization formulation and obtain an optimal myopic policy with 3 stages to go for iid arrivals with general batch sizes. We show analytically that this policy achieves the given target delay ratio in the long run under finite buffer assumption, given that feasibility conditions are satisfied. We take recourse to numerical value iteration to show the existence of average-cost for this policy. Simulations with varied class-weights for Bernoulli arrivals and batch arrivals with Poisson batch sizes show that this policy achieves mean queueing delays closer to the respective target delays than the policy obtained earlier. We also note that the coefficients of variation of the queueing delays of both the classes using cumulative queue lengths are of the same order as those using instantaneous queue lengths. Moreover, the short-term behaviour of the optimal myopic policy using cumulative queue lengths is superior to the existing standard policy reported by Coffman and Mitrani by a factor in the range of 3 to 8. Though our policy performs marginally poorer compared to the value-iterated, sampled, and then stationarily employed policy, the later lacks any closed-form structure. We then modify the definition of the third state variable and look to directly balance weighted mean delays. We come up with another optimal myopic policy with 3 stages to go, following which the error in the ratio of mean delays decreases as the window-size, as opposed to the policy mentioned in the last paragraph, wherein the error decreases as the square-root of the window-size. We perform numerical value-iteration to show the existence of average-cost and study the performance by simulation. Performance of our policy is comparable with the value-iterated, sampled, and then stationarily employed policy, reported by Mallesh. We have then studied general inter-arrival time processes and obtained the optimal myopic policy for the Pareto inter-arrival process, in particular. We have supported with simulation that our policy fares similarly to the PAD policy, reported by Dovrolis et. al., which is primarily heuristic in nature. We then model the possible packet errors in the multiplexed channel by either a Bernoulli process, or a Markov modulated Bernoulli process with two possible channel states. We also consider two possible round-trip-time values for control information, namely zero and one-slot. The policies that are next-stage optimal (for zero round-trip-time), and two-stage optimal (for one-slot round-trip-time) are obtained. Simulations with varied class-weights for Bernoulli arrivals and batch arrivals with Poisson batch sizes show that these policies indeed achieve mean queueing delays very close to the respective target delays. We also obtain the structure for optimal policies with N = 2 + ⌈rtt⌉ stages-to-go for generic values of rtt, and which need not be multiple of time-slots.

Central to the study of Life is knowledge both about the underlying relationships among living things and the processes that have molded them into their diverse forms. Phylogenetics provides a powerful toolkit for investigating both aspects. Bayesian phylogenetics has gained much popularity, due to its readily interpretable notion of probability. However, the posterior probability of a phylogeny, as well as any dependent biological inferences, is conditioned on the assumed model of evolution and its priors, necessitating care in model formulation. In Chapter 1, I outline the Bayesian perspective of phylogenetic inference and provide my view on its most outstanding questions. I then present results from three studies that aim to (i) improve the accuracy of Bayesian phylogenetic inference and (ii) assess when the model assumed in a Bayesian analysis is insufficient to produce an accurate phylogenetic estimate. As phylogenetic data sets increase in size, they must also accommodate a greater diversity of underlying evolutionary processes. Partitioned models represent one way of accounting for this heterogeneity. In Chapter 2, I describe a simulation study to investigate whether support for partitioning of empirical data sets represents a real signal of heterogeneity or whether it is merely a statistical artifact. The results suggest that empirical data are extremely heterogeneous. The incorporation of heterogeneity into inferential models is important for accurate phylogenetic inference. Bayesian phylogenetic estimates of branch lengths are often wildly unreasonable. However, branch lengths are important input for many other analyses. In Chapter 3, I study the occurrence of this phenomenon, identify the data sets most likely to be affected, demonstrate the causes of the bias, and suggest several solutions to avoid inaccurate inferences. Phylogeneticists rarely assess absolute fit between an assumed model of evolution and the data being analyzed. While an approach to assessing fit in a Bayesian framework has been proposed, it sometimes performs quite poorly in predicting a model’s phylogenetic utility. In Chapter 4, I propose and evaluate new test statistics for assessing phylogenetic model adequacy, which directly evaluate a model’s phylogenetic performance. / text