Critério estatístico para obtenção de valores de NSPT para previsão da capacidade de carga de estacas por métodos semi empíricos.

Uma das tarefas mais desafiadoras do engenheiro na área da Geotecnia é a escolha dos valores de parâmetros geotécnicos obtidos de ensaios de campo ou laboratório e que serão utilizados nos modelos analíticos ou numéricos na fase de projeto de fundações. Diante das incertezas inerentes aos ensaios de SPT e da heterogeneidade de abordagens para a utilização dos valores de NSPT, é proposta neste estudo, a aplicação de um critério estatístico para obtenção de valores de NSPT, a partir da construção de intervalos de confiança de 95% de probabilidade em torno da reta ajustada de regressão linear simples entre a variável aleatória NSPT e a profundidade. Os valores obtidos de NSPT pelo critério aplicado foram utilizados na previsão da capacidade de carga de 19 estacas isoladas a partir da utilização de três métodos semi-empíricos: Aoki-Velloso (1975) com coeficientes alterados por Monteiro (1997), Décourt & Quaresma (1978) alterado pelo método de Décourt (1996) e Método de Alonso (1996). As cargas de ruptura dessas 19 estacas ensaiadas através de Provas de Carga Estática foram obtidas pelos métodos de extrapolação de Van Der Veen (1953) e Décourt (1996) e serviram para comparação e consequente validação do critério estatístico. Adicionalmente, com fulcro no item 6.2.1.2.1 da ABNT NBR 6122:2010 Resistência calculada por método semi-empírico, foram avaliados os fatores de segurança em relação às cargas de projeto, inclusive, também se utilizando da premissa de reconhecimento de regiões representativas, levando em conta o número de ensaios de SPT executados, fato que promove uma diminuição da incerteza dos parâmetros, apontando a um menor fator de segurança. A dissertação enfatiza as vantagens de um adequado tratamento estatístico dos parâmetros geotécnicos, a exemplo da recomendação já existente nas normas internacionais como Eurocódigo e outras. O critério construído permite e encoraja análises e decisões racionais no universo das partes interessadas consumidores, projetistas, fiscais de obras, contratantes e comunidade científica promovendo as discussões de forma mais objetiva e harmoniosa sobre o tema.

Strain comparisons in aquaculture species: a manual

When different strains or breeds of a particular species are available, the best choice is seldom immediately obvious for producers. Scientists are also interested in the relative performance of different strains because it provides a basis for recommendations to producers and it often stimulates the conduct of work aimed at unraveling the underlying biological mechanisms involved in the expression of such differences. Hence, strain or breed comparisons of some sort are frequently conducted. This manual is designed to provide general guidelines for the design of strain comparison trials in aquaculture species. Example analyzes are provided using SAS and SPSS. The manual is intended to serve a wide range of readers from developing countries with limited access to information. The users, however, are expected to have a basic knowledge of quantitative genetics and experience in statistical methods and data analysis as well as familiarity with computer software. The manual mainly focuses on the practical aspects of design and data analysis, and interpretation of results.

Controle Gerencial e a Tecnologia da Informação: um estudo de caso na previsão orçamentária em uma organização do setor industrial.

A evolução tecnológica tem feito as empresas se modificarem, e para acompanhar o mercado elas buscam opções que possam ajudar melhor nas tomadas de suas decisões, uma delas é a utilização de tecnologias. A presente pesquisa objetiva analisar a contribuição da tecnologia da informação no orçamento da indústria Alfa. Esta pesquisa é descritiva e exploratória, pois busca descrever a realidade da organização, identificando as características do orçamento da mesma, é quantitativa, pois busca através de métodos estatísticos realizar previsões para o ano de 2013 das demonstrações de resultados advindos dos anos anteriores (2010 a 2012), é também, qualitativa, pois foi elaborado um questionário que pôde auxiliar na interpretação dos dados quantitativos, possibilitando melhores informações sobre o objetivo proposto. Concluiu-se que a tecnologia pode ajudar a melhorar a qualidade da previsão do orçamento da indústria Alfa e o método que melhor se adequou para as estimativas foi a suavização exponencial que demonstrou maior confiabilidade para os resultados.

Quantifying intrapopulation variability in stable isotope data for Spotted Seatrout (Cynoscion nebulosus)

Stable isotope (SI) values of carbon (δ13C) and nitrogen (δ15N) are useful for determining the trophic connectivity between species within an ecosystem, but interpretation of these data involves important assumptions about sources of intrapopulation variability. We compared intrapopulation variability in δ13C and δ15N for an estuarine omnivore, Spotted Seatrout (Cynoscion nebulosus), to test assumptions and assess the utility of SI analysis for delineation of the connectivity of this species with other species in estuarine food webs. Both δ13C and δ15N values showed patterns of enrichment in fish caught from coastal to offshore sites and as a function of fish size. Results for δ13C were consistent in liver and muscle tissue, but liver δ15N showed a negative bias when compared with muscle that increased with absolute δ15N value. Natural variability in both isotopes was 5–10 times higher than that observed in laboratory populations, indicating that environmentally driven intrapopulation variability is detectable particularly after individual bias is removed through sample pooling. These results corroborate the utility of SI analysis for examination of the position of Spotted Seatrout in an estuarine food web. On the basis of these results, we conclude that interpretation of SI data in fishes should account for measurable and ecologically relevant intrapopulation variability for each species and system on a case by case basis.

Drought frequency analysis for California from observed, synthetic, and proxy data

Drought frequency analysis can be performed with statistical techniques developed for determining recurrence intervals for extreme precipitation and flood events (Linsley et al 1992). The drought analysis method discussed in this paper uses the log-Pearson Type III distribution, which has been widely used in flood frequency research. Some of the difficulties encountered when using this distribution for drought analysis are investigated.

The design, construction, operation, and maintenance of the Replicated Modular Estuarine Mesocosm

Perhaps the most difficult job of the ecotoxicologist is extrapolating data calculated from laboratory experiments with high precision and accuracy into the real world of highly-dynamics aquatic environments. The establishment of baseline laboratory toxicity testing data for individual compounds and ecologically important and field studies serve as a precursor to ecosystem level studies needed for ecological risk assessment. The first stage in the field portion of risk assessment is the determination of actual environmental concentrations of the contaminant being studied and matching those concentrations with laboratory toxicity tests. Risk estimates can be produced via risk quotients that would determine the probability that adverse effects may occur. In this first stage of risk assessment, environmental realism is often not achieved. This is due, in part, to the fact that single-species laboratory toxicity tests, while highly controlled, do not account for the complex interactions (Chemical, physical, and biological) that take place in the natural environment. By controlling as many variables in the laboratory as possible, an experiment can be produced in such a fashion that real effects from a compound can be determined for a particular test organism. This type of approach obviously makes comparison with real world data most difficult. Conversely, field oriented studies fall short in the interpretation of ecological risk assessment because of low statistical power, lack of adequate replicaiton, and the enormous amount of time and money needed to perform such studies. Unlike a controlled laboratory bioassay, many other stressors other than the chemical compound in question affect organisms in the environment. These stressors range from natural occurrences (such as changes in temperature, salinity, and community interactions) to other confounding anthropogenic inputs. Therefore, an improved aquatic toxicity test that will enhance environmental realism and increase the accuracy of future ecotoxicological risk assessments is needed.

Statistical analyses to support guidelines for marine avian sampling: Final report. [Digital Supplements A-G attached]

Interest in development of offshore renewable energy facilities has led to a need for high-quality, statistically robust information on marine wildlife distributions. A practical approach is described to estimate the amount of sampling effort required to have sufficient statistical power to identify species specific “hotspots” and “coldspots” of marine bird abundance and occurrence in an offshore environment divided into discrete spatial units (e.g., lease blocks), where “hotspots” and “coldspots” are defined relative to a reference (e.g., regional) mean abundance and/or occurrence probability for each species of interest. For example, a location with average abundance or occurrence that is three times larger the mean (3x effect size) could be defined as a “hotspot,” and a location that is three times smaller than the mean (1/3x effect size) as a “coldspot.” The choice of the effect size used to define hot and coldspots will generally depend on a combination of ecological and regulatory considerations. A method is also developed for testing the statistical significance of possible hotspots and coldspots. Both methods are illustrated with historical seabird survey data from the USGS Avian Compendium Database.

Integration of submersible transect data and high-resolution multibeam sonar imagery for a habitat-based groundfish assessment of Heceta Bank, Oregon

In the face of dramatic declines in groundfish populations and a lack of sufficient stock assessment information, a need has arisen for new methods of assessing groundfish populations. We describe the integration of seafloor transect data gathered by a manned submersible with high-resolution sonar imagery to produce a habitat-based stock assessment system for groundfish. The data sets used in this study were collected from Heceta Bank, Oregon, and were derived from 42 submersible dives (1988–90) and a multibeam sonar survey (1998). The submersible habitat survey investigated seafloor topography and groundfish abundance along 30-minute transects over six predetermined stations and found a statistical relationship between habitat variability and groundfish distribution and abundance. These transects were analyzed in a geographic information system (GIS) by using dynamic segmentation to display changes in habitat along the transects. We used the submersible data to extrapolate fish abundance within uniform habitat patches over broad areas of the bank by means of a habitat classification based on the sonar imagery. After applying a navigation correction to the submersible-based habitat segments, a good correlation with major boundaries on the backscatter and topographic boundaries on the imagery were apparent. Extrapolation of the extent of uniform habitats was made in the vicinity of the dive stations and a preliminary stock assessment of several species of demersal fish was calculated. Such a habitat-based approach will allow researchers to characterize marine communities over large areas of the seafloor.

A statistical model of climates in the southwestern United States

EXTRACT (SEE PDF FOR FULL ABSTRACT): We describe an empirical-statistical model of climates of the southwestern United States. Boundary conditions include sea surface temperatures, atmospheric transmissivity, and topography. Independent variables are derived from the boundary conditions along 1000-km paths of atmospheric circulation. ... Predictor equations are derived over a larger region than the application area to allow for the increased range of paleoclimate. This larger region is delimited by the autocorrelation properties of climatic data.

Snow accumulation time series and their climatic interpretation

EXTRACT (SEE PDF FOR FULL ABSTRACT): Several snow accumulation time series derived from ice cores and extending over 3 to 5 centuries are examined for spatial and temporal climatic information. ... A significant observation is the widespread depression of net snow accumulation during the latter part of the "Little Ice Age". This initially suggests sea surface temperatures were significantly depressed during the same period. However, prior to this, the available core records indicate generally higher than average precipitation rates. This also implies that influences such as shifted storm tracks or a dustier atmosphere may have been involved. Without additional spatial data coverage, these observations should properly be studied using a coupled (global) ocean/atmosphere GCM.

Effects of observation time on interpretation of climatic time series - a need for consistency

Much of what we know about the climate of the United States is derived from data gathered under the auspices of the cooperative climate network. Particular aspects of the way observations are taken can have significant influences on the values of climate statistics derived from the data. These influences are briefly reviewed. The purpose of this paper is to examine their effects on climatic time series. Two other items discussed are: (1) a comparison of true (24-hour) means with means derived from maximums and minimums only, and (2) preliminary work on the times of day at which maximums and minimums are set.

Dynamical structure in paleoclimate data

Deterministic chaos in dynamical systems offers a new paradigm for understanding irregular fluctuations. The theory of chaotic dynamical systems includes methods that can test whether any given set of time series data, such as paleoclimate proxy data, are consistent with a deterministic interpretation. Paleoclimate data with annual resolution and absolute dating provide multiple channels of concurrent time series; these multiple time series can be treated as potential phase space coordinates to test whether interannual climate variability is deterministic. Dynamical structure tests which take advantage of such multichannel data are proposed and illustrated by application to a simple synthetic model of chaos, and to two paleoclimate proxy data series.

Biology and morphometry study of Drepane punctata (Cuv and Val) at juvenile stage of Bombay coast

The metric and meristic characters of Drepane punctata from Versova Fish Landing Centre of Bombay have been studied. The meristic characters showed considerable variations. The number of dorsal fin rays were relatively stable characters. Statistical interpretation of metric data indicated that there is a direct relationship between the preanal, predorsal in relation to total length and eye-diameter in relation to head length.

Mussel recovery and species dynamics at four California rocky intertidal sites: 1992 data report

This is an interim report for a study of mussel recovery and species dynamics at four California rocky intertidal sites. Conducted by Kinnetic Laboratories, Inc. (KLI), and funded by the Minerals Management Service (MMS), the initial experimental field study began in spring 1985 and continued through spring 1991. The initial field study included six sites along the central and northern California coast. In 1992, MMS decided to continue the work started by KLI through an in-house study and establishment of the MMS Intertidal (MINT) team. Four of the original six sites have been continued by MMS. The study methods of the original study have been retained by the MINT team, and close coordination with the original KLI team continues. In 1994, the MMS Environmental Studies Program officially awarded a contract to the MINT team for this in-house study. This interim report presents the results from the fall 1992 sampling, the first year of sampling by the MINT team. The report presents a limited statistical analysis and visual comparison of the 1992 data. The next interim report will include data collected during fall 1994 and will present a broader statistical analysis of both the 1992 and 1994 data sets.

Cross-Lingual spoken language understanding from unaligned data using discriminative classification models and machine translation

This paper investigates several approaches to bootstrapping a new spoken language understanding (SLU) component in a target language given a large dataset of semantically-annotated utterances in some other source language. The aim is to reduce the cost associated with porting a spoken dialogue system from one language to another by minimising the amount of data required in the target language. Since word-level semantic annotations are costly, Semantic Tuple Classifiers (STCs) are used in conjunction with statistical machine translation models both of which are trained from unaligned data to further reduce development time. The paper presents experiments in which a French SLU component in the tourist information domain is bootstrapped from English data. Results show that training STCs on automatically translated data produced the best performance for predicting the utterance's dialogue act type, however individual slot/value pairs are best predicted by training STCs on the source language and using them to decode translated utterances. © 2010 ISCA.