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Semantic mapping using mobile robots

WOLF, Denis F.; SUKHATME, Gaurav S.
Fonte: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC Publicador: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.41%
Robotic mapping is the process of automatically constructing an environment representation using mobile robots. We address the problem of semantic mapping, which consists of using mobile robots to create maps that represent not only metric occupancy but also other properties of the environment. Specifically, we develop techniques to build maps that represent activity and navigability of the environment. Our approach to semantic mapping is to combine machine learning techniques with standard mapping algorithms. Supervised learning methods are used to automatically associate properties of space to the desired classification patterns. We present two methods, the first based on hidden Markov models and the second on support vector machines. Both approaches have been tested and experimentally validated in two problem domains: terrain mapping and activity-based mapping.

Cortical mapping with navigated transcranial magnetic stimulation in low-grade glioma surgery

Paiva, Wellingson S.; Fonoff, Erich T.; Marcolin, Marco A.; Cabrera, Hector N.; Teixeira, Manoel J.
Fonte: DOVE MEDICAL PRESS LTD; ALBANY Publicador: DOVE MEDICAL PRESS LTD; ALBANY
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.39%
Transcranial magnetic stimulation (TMS) is a promising method for both investigation and therapeutic treatment of psychiatric and neurologic disorders and, more recently, for brain mapping. This study describes the application of navigated TMS for motor cortex mapping in patients with a brain tumor located close to the precentral gyrus. Materials and methods: In this prospective study, six patients with low-grade gliomas in or near the precentral gyrus underwent TMS, and their motor responses were correlated to locations in the cortex around the lesion, generating a functional map overlaid on three-dimensional magnetic resonance imaging (MRI) scans of the brain. To determine the accuracy of this new method, we compared TMS mapping with the gold standard mapping with direct cortical electrical stimulation in surgery. The same navigation system and TMS-generated map were used during the surgical resection procedure. Results: The motor cortex could be clearly mapped using both methods. The locations corresponding to the hand and forearm, found during intraoperative mapping, showed a close spatial relationship to the homotopic areas identified by TMS mapping. The mean distance between TMS and direct cortical electrical stimulation (DES) was 4.16 +/- 1.02 mm (range: 2.56-5.27 mm). Conclusion: Preoperative mapping of the motor cortex with navigated TMS prior to brain tumor resection is a useful presurgical planning tool with good accuracy.

Mapeamento da variabilidade espacial das plantas daninhas com a utilização de ferramentas da agricultura de precisão.; Mapping weed spatial variability using precision farming tools.

Shiratsuchi, Luciano Shozo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/12/2001 PT
Relevância na Pesquisa
36.42%
Tradicionalmente o manejo das plantas daninhas é realizado levando-se em consideração a infestação média destas plantas nas áreas agrícolas; sendo então adotadas estratégias de manejo de forma homogênea em toda a área. Porém, as plantas daninhas não se distribuem uniformemente, sendo comum o comportamento contagioso, formando manchas ou “reboleiras”. No entanto, a localização e mapeamento de diferentes infestações são tarefas difíceis de serem executadas em larga escala e requerem metodologias adequadas. Desta forma, métodos de determinação dessa variabilidade espacial necessitam de melhores esclarecimentos e estudos científicos. Com o objetivo de estudar o comportamento da variabilidade espacial das plantas daninhas e seu respectivo banco de sementes com a utilização de ferramentas da agricultura de precisão, foram realizados quatro experimentos para avaliar esta variabilidade espacial e temporal e analisar a potencialidade que a mesma pode proporcionar para o manejo racional das plantas daninhas, principalmente a possibilidade da aplicação localizada de herbicidas. O primeiro experimento consistiu do mapeamento do banco de sementes ao longo de dois anos consecutivos no intuito de comparar sua variabilidade espacial com a flora emergente. Concluiu-se que existe uma correlação entre o banco de sementes e a flora emergente e entre bancos de sementes de anos consecutivos...

Mapeamento de perigo de escorregamentos em áreas urbanas precárias brasileiras com a incorporação do Processo de Análise Hierárquica (AHP); Landslides hazard mapping in Brazilian poor and slum urban areas with the application of the AHP method

Faria, Daniela Girio Marchiori
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/10/2011 PT
Relevância na Pesquisa
36.41%
As áreas urbanas precárias, também denominadas de favelas são as mais frequentemente afetadas por escorregamentos e também as mais vulneráveis, gerando danos sociais de maior monta. Este cenário resultou na demanda e no desenvolvimento de uma série de ações do poder público em diferentes municípios e estados brasileiros, culminando com o estabelecimento de um programa federal, vinculado ao Ministério das Cidades, voltado à mitigação destes riscos com o desenvolvimento de mapeamentos e a implantação de planos preventivos de defesa civil, de obras de estabilização e de reurbanização nestas áreas de risco. No estado de São Paulo, o mapeamento de escorregamento em encostas urbanas precárias vem sendo realizado desde 1990, através das iniciativas de órgãos públicos e com a participação de diversas instituições. O método de mapeamento atualmente mais utilizado emprega como técnicas principais a realização de vistorias sistemáticas de campo, investigações de superfície, utilização de fichas descritivas para armazenar as informações coletadas e a delimitação de setores de risco em imagens aéreas recentes e de grande escala e de detalhe. Este método é bastante aplicado e muitas vezes consegue subsidiar satisfatoriamente as ações de mitigação dos riscos de escorregamentos...

Avaliação da estimulação magnética transcraniana navegada no mapeamento anatômico e funcional não invasivo do córtex motor; Evaluation of navigated transcranial magnetic stimulation in anatomical and functional mapping of the motor cortex

Paiva, Wellingson Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/05/2012 PT
Relevância na Pesquisa
36.44%
Introdução e objetivos: A estimulação magnética transcraniana (EMT) é um método exclusivo para estimulação cerebral não-invasiva. A diferença fundamental entre EMT e as outras técnicas disponíveis de mapeamento por imagem do cérebro é que se estabelece haver uma relação de causa e efeito entre a resposta fisiológica evocada e o estímulo magnético. A relação entre estrutura e função como a principal característica, constitui uma modalidade de mapeamento cerebral ainda não estabelecido. Os recentes avanços no processamento de imagem permitiram refinar EMT através de sua combinação com a ressonância magnética utilizando-se do sistema de neuronavegação para orientar o posicionamento da bobina em relação ao córtex. Assim a posição da bobina sobre o couro cabeludo pode ser mantida constante conforme verificado pela orientação de navegação em tempo real com registro visual. O objetivo deste estudo foi avaliar a utilidade da EMT no mapeamento cortical motor em comparação com o mapeamento cirúrgico com estimulação cortical direta. Métodos: O estudo foi conduzido com 30 mapeamentos consecutivos em pacientes com programação de cirurgia para tumores adjacentes ao córtex motor. O mapeamento pré-operatório foi realizado com o sistema de estimulação magnética transcraniana navegada. Esta estimulação gera um pulso magnético através de uma bobina. Este método permite estimulação diretamente no córtex cerebral. Eletródios de superfície foram anexados ao abdutor curto do polegar. Em seguida...

Mapeamento estático de processos MPI com emparelhamento perfeito de custo máximo em cluster homogêneo de multi-cores; Static MPI processes mapping using maximum weighted perfect matching at homogeneous multi-core clusters

Ferreira, Manuela Klanovicz
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.39%
Um importante fator que precisa ser considerado para alcançar alto desempenho em aplicações paralelas é a distribuição dos processos nos núcleos do sistema, denominada mapeamento de processos. Mesmo o mapeamento estático de processos é um problema NP-difícil. Por esse motivo, são utilizadas heurísticas que dependem da aplicação e do hardware no qual a aplicação será mapeada. Nas arquiteturas atuais, além da possibilidade de haver mais de um processador por nó do cluster, é possível haver mais de um núcleo de processamento por processador, assim, o mapeamento estático de processos pode considerar pelo menos três níveis de comunicação entre os processos que executam em um cluster multi-core: intra-chip, intra-nó e inter-nó. Este trabalho propõe a heurística MapEME (Mapeamento Estático MPI com Emparelhamento) que emprega o Emparelhamento Perfeito de Custo Máximo (EPCM) no cálculo do mapeamento estático de processos paralelos MPI em processadores multi-core. Os resultados alcançados pelo mapeamento gerado pela MapEME são comparados aos resultados obtidos pelo mapeamento gerado pela aplicação Scotch, que utiliza o Biparticionamento Recursivo Dual (BRD), já utilizado como heurística para mapeamento estático de processos. Ambas as heurísticas são comparadas à Busca Exaustiva (BE) para verificar o quanto estão próximas do ótimo. Os três métodos têm a complexidade e o ganho no tempo de execução em ralação à distribuição padrão da biblioteca MPICH2 comparados entre si. A principal contribuição deste trabalho é mostrar que a heurística EPCM apresenta ganho de até 40% equivalente a já difundida BRD...

Construção de um mapa funcional em cana-de-açúcar e mapeamento de QTLs de importância econômica = : Functional genetic map construction in sugarcane and QTL mapping of economic importance; Functional genetic map construction in sugarcane and QTL mapping of economic importance

Estela Araujo Costa
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/02/2015 PT
Relevância na Pesquisa
36.39%
A grande importância da cana-de-açúcar e seus derivados tem resultado em grande investimento financeiro e científico. Esse fato se deve, principalmente, à complexidade do genoma da cana e às dificuldades encontradas na obtenção de novas cultivares mais produtivas, através dos métodos tradicionais de seleção. A construção de mapas genéticos de ligação permite associar locos mapeados com características de interesse econômico, podendo acelerar o processo de melhoramento da espécie. Logo, a utilização dos marcadores em estudos de mapeamento genético e de QTL¿s (Quantitative Trait Loci) tem proporcionado um importante progresso no conhecimento da estrutura genética e genômica da cana-de-açúcar. Utilizando uma população segregante derivada do cruzamento entre as variedades comerciais IACSP95-3018 e IACSP93-3046, contendo 187 indivíduos F1, esta tese teve como objetivo realizar o mapeamento genético funcional e o mapeamento de QTLs de características de importância econômica. Para tanto, as características avaliadas foram diâmetro, peso, altura, porcentagem de fibra, conteúdo de sacarose (Pol) e conteúdo de sólido solúvel (Brix), em dois locais, por três anos (2012, 2013 e 2014) que se juntaram a dois outros anos...

The effect of spatial aggregation on performance when mapping a risk of disease

Jeffery, Caroline; Ozonoff, Al; Pagano, Marcello
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.39%
Background: Spatial data on cases are available either in point form (e.g. longitude/latitude), or aggregated by an administrative region (e.g. zip code or census tract). Statistical methods for spatial data may accommodate either form of data, however the spatial aggregation can affect their performance. Previous work has studied the effect of spatial aggregation on cluster detection methods. Here we consider geographic health data at different levels of spatial resolution, to study the effect of spatial aggregation on disease mapping performance in locating subregions of increased disease risk. Methods: We implemented a non-parametric disease distance-based mapping (DBM) method to produce a smooth map from spatially aggregated childhood leukaemia data. We then simulated spatial data under controlled conditions to study the effect of spatial aggregation on its performance. We used an evaluation method based on ROC curves to compare performance of DBM across different geographic scales. Results: Application of DBM to the leukaemia data illustrates the method as a useful visualization tool. Spatial aggregation produced expected degradation of disease mapping performance. Characteristics of this degradation, however, varied depending on the interaction between the geographic extent of the higher risk area and the level of aggregation. For example...

Modelling and digital soil mapping of the organic carbon stock in the topsoil (0-10 cm) of Rio de Janeiro State, Brazil.

MENDONÇA-SANTOS, M. L.; SANTOS, H. G.; COELHO, M. R.
Fonte: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 3, 30 Sept. - Oct. 3, 2008, Logan, Utah. Bridging research, production, and environmental applications: papers. Publicador: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 3, 30 Sept. - Oct. 3, 2008, Logan, Utah. Bridging research, production, and environmental applications: papers.
Tipo: Artigo em anais de congresso (ALICE) Formato: 10 p.
EN
Relevância na Pesquisa
46.27%
A soil database with 431 soil profiles of Rio de Janeiro State was used in the scope of a research project entitled ?Quantifying the magnitude, spatial distribution and organic carbon in soils of Rio de Janeiro State, using quantitative modeling, GIS and database technologies? (Projeto Carbono_RJ, funded by FAPERJ - Carlos Chagas Filho Foundation for Research Support in Rio de Janeiro State). Considering that these soil data were collected to other purpose, there was only a few sparse data to soil bulk density, which is essential to estimate of soil organic carbon (SOC) stock. To face this problem, pedotransfer functions (PTFs) were estimated to be used in the modeling of organic soil carbon of topsoil (0-10 cm), using s.c.o.r.p.a.n model. The following environmental correlates were used as predictor variables: satellite data, lithology and soil maps, DEM (Digital Elevation Model) and its derivatives as source of information for these variables. This dataset, that represents the best organized soil dataset in Brazil, is working as a trial for learning/teaching of Digital Soil Mapping (DSM) using a variety of methods for predicting soil classes and their properties. The "f" of the equation was modeled by means of multilinear analysis and regression-kriging. Seven different models were built and compared through statistical methods. In a general way...

The Use of GIS and Digital Elevation Model in Digital Soil Mapping: a case study from São Paulo, Brazil.

VALLADARES, G. S.; HOTT, M. C.
Fonte: In: HARTEMINK, A. E.; McBRATNEY, A.; MENDONÇA-SANTOS, M. L. (Ed.). Digital Soil mapping with limited data. Netherlands: Springer, 2008. Publicador: In: HARTEMINK, A. E.; McBRATNEY, A.; MENDONÇA-SANTOS, M. L. (Ed.). Digital Soil mapping with limited data. Netherlands: Springer, 2008.
Tipo: Capítulo em livro técnico-científico (ALICE) Formato: p. 349-356.
EN
Relevância na Pesquisa
46.27%
This paper applied pedological mapping in an experimental center of APTA-Frutas in Jundiaí São Paulo, Brazil, using morphometric parameters and GIS tools. The aim of this work was to obtain a preliminary legend of a soil map and to compare the preliminary map with maps made by the traditional soil survey methods. The area has 59 hectares and is located at a mountainous relief in the Atlantic Plateau. The original soil map of this area was made at 1:10 000. A digital elevation model (DEM) was generated with 4m spatial resolution based on a topographical map at 1:10 000 scale, where the level curves are equidistant at 5 m. Based on the DEM we generated altitude, curvature and slope maps. In order to map the hydromorphic soils it was generated a buffer around the hydrography. We also calculated frequency distribution graphics of altitude, curvature and slope maps. After the interpretation of the frequency distribution, we defined classes to predict the soils types. The curvature map was divided into two class intervals (< or = 0 and > 0), the altitude map was divided into four class intervals (690, 703, 704,714, 715, 730, and 731, 757 m), and the slope map was divided into four class intervals (0-9, 10-19, 20-44, and 45-72%). The maps were reclassified and converted to shape files. The shape files were intersected with the others to generate the final preliminary soil map. The methodology was adequate for the preliminary mapping of some types of soils.; 2008

An Architecture-Independent Graphical Tool for Automatic Contention-Free Process-to-Processor Mapping

Shen, H.; Lor, S.; Maheshwari, P.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2001 EN
Relevância na Pesquisa
36.44%
Mapping of parallel programs onto parallel computers for efficient execution is a fundamental problem of great significance in parallel processing. This paper presents an architecture-independent software tool for contention-free mapping of arbitrary parallel programs onto parallel computers with arbitrary configurations. This mapping tool is based on an efficient heuristic algorithm that runs in time O(n 3+m 4) in the worst case for mapping n tasks onto m processors, where m n in most practical cases. It is fully implemented and incorporated into a graph editing system to produce a graphical mapping tool which enables its user to monitor and control the mapping process. The user can assist the mapping process or employ the algorithm to map automatically. Our mapping tool has been tested and its performance evaluated extensively. Experimental results show that our tool combines user intuition and mapping heuristics effectively to make it a powerful mapping tool which is practical to use. Our mapping tool can be easily extended for use in the more general case when the link contention-degree is bounded to a fixed system-specified value without increasing its complexity.; Hong Shen, Sam Lor and Piyush Maheshwari; The original publication is available at www.springerlink.com

Evaluating hyperspectral imagery for mapping the surface symptoms of dryland salinity

Dutkiewicz, Anna
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 254946 bytes; 3049109 bytes; 2825739 bytes; 111849 bytes; application/pdf; application/pdf; application/pdf; application/pdf
Publicado em //2006 EN
Relevância na Pesquisa
36.42%
Airborne hyperspectral imagery has the potential to overcome the spectral and spatial resolution limitations of multispectral satellite imagery for monitoring salinity at both regional and farm scales. In particular, saline areas that have good cover of salt tolerant plants are difficult to map with multispectral satellite imagery. Hyperspectral imagery may provide a more reliable salinity mapping method because of its potential to discriminate halophytic plant cover from non - halophytes. HyMap and CASI airborne imagery ( at 3m ground resolution ) and Hyperion satellite imagery ( at 30 resolution ) were acquired over a 140 sq km dryland agricultural area in South Australia, which exhibits severe symptoms of salinity, including extensive patches of the perennial halophytic shrub samphire ( Halosarcia pergranulata ), sea barley grass ( Hordeum marinum ) and salt encrusted pans. The HyMap and Hyperion imagery were acquired in the dry season ( March and February respectively ) to maximise soil and perennial vegetation mapping. The optimum time of year to map sea barley grass, an annual species, was investigated through spectral discrimination analysis. Multiple reflectance spectra were collected of sea barley grass and other annual grasses with an ASD Fieldspec Pro spectrometer during the September spring flush and in November during late senescence. Comparing spectra of different species in November attempted to capture the spectral differences between the late senescing sea barley grass and other annual grasses. Broad NIR and SWIR regions were identified where sea barley grass differs significantly from other species in November during late senescence. The sea barley grass was therefore shown to have the potential to be discriminated and mapped with hyperspectral imagery at this time and as a result the CASI survey was commission for November. Other salinity symptoms were characterised by collecting single field and laboratory spectra for comparison to image derived spectra in order to provide certainty about the landscape components that were to be mapped. Endmembers spectra associated with saltpans and samphire patches were extracted from the imagery using automated endmember generation procedures or selected regions of interest and used in subsequent partial unmixing. Spectral subsets were evaluated for their ability to optimise salinity maps. The saltpan spectra contained absorption features consistent with montmorillonite and gypsum. A single gypsum endmember from one image strip successfully mapped saltpans across multiple images strips using the 1750 nm absorption feature as the input to matched filter unmixing. The individual spectra of green and red samphire are dominated by photosynthetic vegetation characteristics. The spectra of green samphire...

BAC-HAPPY Mapping (BAP Mapping): a new and efficient protocol for physical mapping

Vu, G.; Dear, P.; Caligari, P.; Wilkinson, M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
36.43%
Physical and linkage mapping underpin efforts to sequence and characterize the genomes of eukaryotic organisms by providing a skeleton framework for whole genome assembly. Hitherto, linkage and physical “contig” maps were generated independently prior to merging. Here, we develop a new and easy method, BAC HAPPY MAPPING (BAP mapping), that utilizes BAC library pools as a HAPPY mapping panel together with an Mbp-sized DNA panel to integrate the linkage and physical mapping efforts into one pipeline. Using Arabidopsis thaliana as an exemplar, a set of 40 Sequence Tagged Site (STS) markers spanning ~10% of chromosome 4 were simultaneously assembled onto a BAP map compiled using both a series of BAC pools each comprising 0.7x genome coverage and dilute (0.7x genome) samples of sheared genomic DNA. The resultant BAP map overcomes the need for polymorphic loci to separate genetic loci by recombination and allows physical mapping in segments of suppressed recombination that are difficult to analyze using traditional mapping techniques. Even virtual “BAC-HAPPY-mapping” to convert BAC landing data into BAC linkage contigs is possible.; Giang T. H. Vu, Paul H. Dear, Peter D. S. Caligari and Mike J. Wilkinson

New regolith mapping approaches for old Australian landscapes.

Wilford, John Richard
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
36.46%
The regolith, or ‘critical zone’, forms a discontinuous layer that covers large areas of Earth’s terrestrial surface. It is a dynamic zone that forms and changes through time in response to interactions between air, rocks (minerals), water and biota. Knowledge of regolith is critical because of its key role in supporting terrestrial life, through physical, chemical and biological processes that operate at mineral-water interaction scales up to the regional scale through geological and tectonic activity. There are many disciplines or areas of applied integrated research that rely on an improved understanding of regolith formation and information on surface and sub-surface regolith properties at appropriate spatial scales. These areas of study include; agriculture, land use sustainability, hydrology, salinity management, ecology, mineral exploration, natural hazard risk assessment and civil engineering. Furthermore, mapping regolith is critical in understanding the origin and evolution of regolith through space and time. Mapping the regolith and formulation of associated robust process models are in their infancy compared with geological and soil mapping, which have had a long history of development and refinement. Regolith mapping can be seen as a hybrid approach combining elements from the existing mapping disciplines of geology...

Mapping, Path Following, and Perception with Long Range Passive UHF RFID for Mobile Robots

Liu, Ran
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertação
EN
Relevância na Pesquisa
36.44%
Service robots have shown an impressive potential in providing assistance and guidance in various environments, such as supermarkets, shopping malls, homes, airports, and libraries. Due to the low-cost and contactless way of communication, radio-frequency identification (RFID) technology provides a solution to overcome the difficulties (e.g. occlusions) that the traditional line of sight sensors (e.g. cameras and laser range finders) face. In this thesis, we address the applications of using passive ultra high frequency (UHF) RFID as a sensing technology for mobile robots in three fundamental tasks, namely mapping, path following, and tracking. An important task in the field of RFID is mapping, which aims at inferring the positions of RFID tags based on the measurements (i.e. the detections as well as the received signal strength) received by the RFID reader. The robot, which serves as an intelligent mobile carrier, is able to localize itself in a known environment based on the existing positioning techniques, such as laser-based Monte Carlo localization. The mapping process requires a probabilistic sensor model, which characterizes the likelihood of receiving a measurement, given the relative pose of the antenna and the tag. In this thesis...

GIS Tools for 3-D Surficial Mapping in Ohio

McDonald, James; Pavey, Richard R.; Venteris, Erik R.; Wells, Joseph G.
Fonte: U.S. Geological Survey Publicador: U.S. Geological Survey
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
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This poster was presented at the 2007 meeting of the Digital Mapping Techniques Conference in Columbia, South Carolina, May 20-23, 2007.; The Ohio Department of Natural Resources, Division of Geological Survey is currently mapping the surficial geology of Ohio in three dimensions (3-D) using a modified version of the stack-mapping technique of Kempton (1981). The stack-mapping technique depicts the geology for an area in 3-D by listing the unconsolidated (mostly glacial) geologic units from the surface to bedrock, the thickness of each unit, and the underlying bedrock unit. The new mapping of the surficial geology is intended to replace the older and smaller-scale mapping that was based upon generalized, two-dimensional mapping techniques. Three ArcMap-based software applications were developed to assist with the stack-unit mapping program. The first software application used the lithologies from water wells to create on-screen graphics representing the stratigraphic columns for each well record. These stratigraphic columns are interpreted by the geologist to assign a generalized stack unit for each polygon. The second software application consists of two tools used to attribute and label the stack-map polygons, which will capture the information in the GIS and for cartographic display. The first tool attributes a one-to-many relationship between a surficial-geology polygon and the lithology table. The second tool labels the surficial-geology polygons with the stack text for use in map publishing. The third application performs custom queries against the lithology table that can be used to create derivative mapping products...

The effects of anaesthetic agents on cortical mapping during neurosurgical procedures involving eloquent areas of the brain

Adhikary, S.; Thiruvenkatarajan, V.; Babu, K.; Tharyan, P.
Fonte: Update Software Ltd Publicador: Update Software Ltd
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
Relevância na Pesquisa
36.41%
BACKGROUND: In patients presenting for surgical resection of lesions involving, or adjacent to, the functionally important eloquent cortical areas, it is vital to achieve complete or near complete resection of the pathology without damaging the healthy surrounding tissues.The eloquent areas that the surgeons are concerned with are the primary motor, premotor cortex, supplementary motor cortex and speech areas. If the lesions are within these regions surgeons could either take a biopsy or do a intracapsular decompression without damaging the mentioned areas to avoid postoperative dysfunction. If the lesions are adjacent to the above mentioned areas, the normal anatomy would get distorted. However, proper identification of the above mentioned areas would enable the surgeon to radically remove the tumours. Intraoperative mapping of the cortex with stimulating and recording electrodes is termed as electrophysiological (EP) mapping.The EP mapping of motor, sensory and language cortex is widely employed in the resection of lesions involving or adjacent to the eloquent areas. Both intravenous and inhalational agents are known to affect these EP mapping techniques. OBJECTIVES: The aim of this review was to evaluate the effect of anaesthetic agents on intra-operative EP mapping in patients undergoing neurosurgical procedures involving...

Comparison of epicardial mapping and noncontact endocardial mapping in dog experiments and computer simulations

Sabouri, Sepideh
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
36.41%
La fibrillation auriculaire, l'arythmie la plus fréquente en clinique, affecte 2.3 millions de patients en Amérique du Nord. Pour en étudier les mécanismes et les thérapies potentielles, des modèles animaux de fibrillation auriculaire ont été développés. La cartographie électrique épicardique à haute densité est une technique expérimentale bien établie pour suivre in vivo l'activité des oreillettes en réponse à une stimulation électrique, à du remodelage, à des arythmies ou à une modulation du système nerveux autonome. Dans les régions qui ne sont pas accessibles par cartographie épicardique, la cartographie endocardique sans contact réalisée à l'aide d'un cathéter en forme de ballon pourrait apporter une description plus complète de l'activité auriculaire. Dans cette étude, une expérience chez le chien a été conçue et analysée. Une reconstruction électro-anatomique, une cartographie épicardique (103 électrodes), une cartographie endocardique sans contact (2048 électrodes virtuelles calculées à partir un cathéter en forme de ballon avec 64 canaux) et des enregistrements endocardiques avec contact direct ont été réalisés simultanément. Les systèmes d'enregistrement ont été également simulés dans un modèle mathématique d'une oreillette droite de chien. Dans les simulations et les expériences (après la suppression du nœud atrio-ventriculaire)...

Ontology mapping evolution

Martins, Hélio Artur Mendes
Fonte: Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto Publicador: Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto
Tipo: Dissertação de Mestrado
Publicado em //2008 ENG
Relevância na Pesquisa
36.43%
Introdução Hoje em dia, o conceito de ontologia (Especificação explícita de uma conceptualização [Gruber, 1993]) é um conceito chave em sistemas baseados em conhecimento em geral e na Web Semântica em particular. Entretanto, os agentes de software nem sempre concordam com a mesma conceptualização, justificando assim a existência de diversas ontologias, mesmo que tratando o mesmo domínio de discurso. Para resolver/minimizar o problema de interoperabilidade entre estes agentes, o mapeamento de ontologias provou ser uma boa solução. O mapeamento de ontologias é o processo onde são especificadas relações semânticas entre entidades da ontologia origem e destino ao nível conceptual, e que por sua vez podem ser utilizados para transformar instâncias baseadas na ontologia origem em instâncias baseadas na ontologia destino. Motivação Num ambiente dinâmico como a Web Semântica, os agentes alteram não só os seus dados mas também a sua estrutura e semântica (ontologias). Este processo, denominado evolução de ontologias, pode ser definido como uma adaptação temporal da ontologia através de alterações que surgem no domínio ou nos objectivos da própria ontologia, e da gestão consistente dessas alterações [Stojanovic...

Simulated color gamut mapping using simple rendered images

Montag, Ethan; Fairchild, Mark
Fonte: The International Society for Optical Engineering (SPIE) Publicador: The International Society for Optical Engineering (SPIE)
Tipo: Artigo de Revista Científica
EN_US
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In order to systematically evaluate different gamut mapping algorithms, we have simulated gamut mapping on a CRT using simple rendered images of colored spheres floating in front of a gray background. Using CIELab as our device-independent color space, cut-off values for lightness and chroma, based on the statistics of the images, were chosen to reduce the gamuts for the test images. The gamut mapping algorithms consisted of combination of clipping and linearly mapping the original gamut in piecewise segments. Complete color space compression in RGB and CIELAB was also used. Each of the colored originals (R,G,B,C,M,Y, and Skin) were mapped separately in lightness and chroma. In addition, each algorithm was implemented with saturation (C*/L*) allowed to vary or remain constant. Using a paired-comparison paradigm, pairs of test images with reduced color gamuts were presented to twenty subjects along with the original image. For each pair the subjects chose the test images that better reproduced the original. Rank orders and interval scales of algorithm performance with confidence limits were then derived. Certain algorithms were found to perform best consistently over image color. For chroma mapping, clipping of all out-of-gamut colors while keeping lightness constant was the most preferred method. For lightness mapping at the top of the gamut...