6,081 research outputs found

    Graphics + Robotics + AI = Fast, 3D Scene Construction

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    Sceneconstruction is the process of building realis- tic, three-dimensionalrepresentations, or models,of real world environments, such as rooms, landsacpes or buildings. Because of the realistic quality of images being produced, current scene construction algorithms require manualprocessing by humanexperts. However, the benefits of having such 3Dmodelsare great. Con- sider a situation where a three-dimensional modelof an evironment must be created in real-time. Existing scene construction algorithms will not su~ce. There- fore we have outlined a newarea of quick and dirty scene construction whereusable, lowresolution, three- dimensional models of real world environments can be created in real time. This paper describes the need for such a system, and provides a generalized approachfor accomplishingthe task

    Graphics + Robotics + AI = Fast, 3D Scene Construction

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    Sceneconstruction is the process of building realis- tic, three-dimensionalrepresentations, or models,of real world environments, such as rooms, landsacpes or buildings. Because of the realistic quality of images being produced, current scene construction algorithms require manualprocessing by humanexperts. However, the benefits of having such 3Dmodelsare great. Con- sider a situation where a three-dimensional modelof an evironment must be created in real-time. Existing scene construction algorithms will not su~ce. There- fore we have outlined a newarea of quick and dirty scene construction whereusable, lowresolution, three- dimensional models of real world environments can be created in real time. This paper describes the need for such a system, and provides a generalized approachfor accomplishingthe task

    Multicomponent dynamical systems: SRB measures and phase transitions

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    We discuss a notion of phase transitions in multicomponent systems and clarify relations between deterministic chaotic and stochastic models of this type of systems. Connections between various definitions of SRB measures are considered as well.Comment: 13 pages, LaTeX 2

    Precision measurement of the half-life and the decay branches of 62Ga

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    In an experiment performed at the Accelerator Laboratory of the University of Jyvaskyla, the beta-decay half-life of 62Ga has been studied with high precision using the IGISOL technique. A half-life of T1/2 = 116.09(17)ms was measured. Using beta-gamma coincidences, the gamma intensity of the 954keV transition and an upper limit of the beta-decay feeding of the 0+_2 state have been extracted. The present experimental results are compared to previous measurements and their impact on our understanding of the weak interaction is discussed.Comment: 7 pages, 7 figures, submitted to EPJ

    Analysis of genetic diversity of Hyptis pectinata (L.) Poit. plants using ISSR markers.

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    Made available in DSpace on 2018-01-26T23:44:48Z (GMT). No. of bitstreams: 1 Artigo7GMRRosanagmr1603gmr.16039603.pdf: 1478794 bytes, checksum: d02d751f935ebcf252a958022e477f4e (MD5) Previous issue date: 2017-09-28bitstream/item/164465/1/Artigo-7-GMR-Rosana-gmr-16-03-gmr.16039603.pd

    Passive Techniques for Controlling the Flow in Supersonic Wing - Body Junctions

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    Junction flows are common to all flight speeds and they are associated with undesirable features such as increases in drag, limitations on performance and at supersonic speeds high heat transfer rates. Junction flows are associated with performance losses in turbomachinery (around 30% of the total pressure losses in an axial turbine) and they can lead to premature detection of military underwater vessels. Junction fairings are widely used at subsonic speeds and correct fairing of the C-141 wing alone, could have resulted in potential fuel savings of approximately US 40,000peryearperaircraftwhichcanberoughlytranslatedintoa 40,000 per year per aircraft which can be roughly translated into a 600,000 saving during the lifetime of each airframe. Typically, for a modern transport type of aircraft the wing juncture accounts for between 1 and 2 % of cruise drag and therefore, careful design of the wing junction is necessary. At supersonic speeds, by far the most disadvantageous feature associated with juncture design is high heat transfer rates due to shock / shock interaction. These heat transfer rates are sufficient to cause severe structural damage leading to component burn-off. Typical leading edge temperatures during re-entry for an aerospaceplane, like HOTOL, are around 2000 K, exclusive of increases in temperature caused by the interaction. Although drag reduction may not be so relatively critical at these flight speeds, the potential loss of control components, like stabilising fins, needs to be carefully examined and some configuration re-design may be necessary as a consequence. This research project is aimed at developing a technique through which the disadvantageous features associated with supersonic junction designs can be alleviated. It was found that through re-design of the wing / body junction the maximum mean static pressure local to the fin leading edge could be halved, the strength of the junction vortices could be lowered and the amount of separated flow reduced. The applications of the technology span all vehicles operating within the supersonic flight regime and therefore, the markets to which the technology is applicable are military aircraft, defence systems, aerospaceplanes and commercial supersonic transports. As the technology is, in principle, applicable to the design of commercial supersonic transport aircraft (HSCT) and the market for these vehicles is forecast to be worth up to $ 200 billion (FY 1987) an examination of the issues behind marketing this type of vehicle is presented in the non¬technical section. The presently available data produced by the major manufacturers were found to be lacking in the following areas (a) evaluations of market elasticity, (b) distribution techniques, (c) the availability of acquisition finance and financing techniques, (d) political sensitivity analysis (d) product life cycle analysis and (f) the relationship marketing of the venture.Ph

    Genetic divergence in basil cultivars and hybrids.

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    Basil is an aromatic herb that stands out fo its economic importance. It is consumed in natura and sed to obtain essential oil. The cultivation of this species in several regions of the world has allowed variations by natural crosses and euploidy, leading to the wide genetic variability found nowadays. Considering the importance of this species, we aimed to analyze the genetic diversity of 27 basil genotypes using ISSR molecular markers. Fourteen primers were employed for DNA amplification, resulting in 86% polymorphism. Based on the Jaccard?s dissimilarity index, the highest index (0.80) was observed between the individuals BAS001 and BAS012, while the lowest index (0.18) was detected between the genotypes BAS014 and BAS015. The genetic similarity among individuals was calculated, forming four distinct clusters. Most individuals (40.7%) were allocated in cluster I. The polymorphic information content (PIC) (0.89) indicated considerable levels of genetic diversity among genotypes. In this sense, the ISSR markers were efficient in the detection of polymorphisms between the accessions, suggesting the genetic variability of the collection. This result demonstrates the importance of the use of molecular markers and the advantages that this information provides to the breeding of the species. O manjericão é uma erva aromática que se destaca por possuir importância econômica. É consumido in natura e também utilizado na obtenção de óleo essencial. O cultivo desta espécie em diversas regiões do mundo permitiu que surgissem variações mediante cru-zamentos naturais e euploidia, ocasionando a ampla variabilidade genética existente. Considerando a importância desta espécie, este trabalho teve como objetivo analisar a diversidade genética de 27 genótipos de manjericão usando marcadores moleculares ISSR. Qua-torze primers foram utilizados para amplificação do DNA, resultando em 86% de polimorfismo. Com base no índice de dissimilaridade de Jaccard, observou-se o maior índice (0,80) entre os indivíduos BAS001 e BAS012, enquanto que o menor índice de dissimilari-dade (0,18) foi detectado entre os genótipos BAS014 e BAS015. A semelhança genética entre indivíduos foi calculada, formando quatro grupos distintos. A maioria dos indivíduos (40,7%) foi agrupada no grupo I. O conteúdo de informação polimórfica (PIC) (0,89) indicou níveis consideráveis de diversidade genética entre os genótipos. Neste sentido, os marcadores ISSR foram eficientes na detecção de polimorfismos entre os acessos e confirmaram que é possível inferir a variabilidade genética na coleção. Isso demonstra a importância do uso de marcadores moleculares e as vantagens que esta informação pode oferecer ao melhoramento genético das espécies

    On the discovery of doubly-magic 48^{48}Ni

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    The paper reports on the first observation of doubly-magic Nickel-48 in an experimental at the SISSI/LISE3 facility of GANIL. Four Nickel-48 isotopes were identified. In addition, roughly 100 Nickel-49, 50 Iron-45, and 290 Chromium-42 isotopes were observed. This opens the possibility to search for two-proton emission from these nuclei.Comment: 4 pages, 3 figures, accepted for publication in Phys. Rev. Let

    First observation of 54Zn and its decay by two-proton emission

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    The nucleus 54Zn has been observed for the first time in an experiment at the SISSI/LISE3 facility of GANIL in the quasi-fragmentation of a 58Ni beam at 74.5 MeV/nucleon in a natNi target. The fragments were analysed by means of the ALPHA-LISE3 separator and implanted in a silicon-strip detector where correlations in space and time between implantation and subsequent decay events allowed us to generate almost background free decay spectra for about 25 different nuclei at the same time. Eight 54Zn implantation events were observed. From the correlated decay events, the half-life of 54Zn is determined to be 3.2 +1.8/-0.8 ms. Seven of the eight implantations are followed by two-proton emission with a decay energy of 1.48(2) MeV. The decay energy and the partial half-life are compared to model predictions and allow for a test of these two-proton decay models.Comment: 4 pages, 4 figures, accepted for publication in PR

    Beta-decay branching ratios of 62Ga

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    Beta-decay branching ratios of 62Ga have been measured at the IGISOL facility of the Accelerator Laboratory of the University of Jyvaskyla. 62Ga is one of the heavier Tz = 0, 0+ -> 0+ beta-emitting nuclides used to determine the vector coupling constant of the weak interaction and the Vud quark-mixing matrix element. For part of the experimental studies presented here, the JYFLTRAP facility has been employed to prepare isotopically pure beams of 62Ga. The branching ratio obtained, BR= 99.893(24)%, for the super-allowed branch is in agreement with previous measurements and allows to determine the ft value and the universal Ft value for the super-allowed beta decay of 62Ga
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