47 research outputs found

    Analysis on Solar Panel Crack Detection Using Optimization Techniques

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    A Solar panel is considered as a proficient power hotspot for the creation of electrical energy for long years. Any deformity on the solar cell panel’s surface will prompt to decreased production of power and loss in the yield. Subsequently, the location of cracks on solar panel surfaces is the most essential stride during the inspection of solar panel, and it has important significance. In any case, these strategies cost lot of computation time and with low precision. Aiming for a few issues of the existing algorithm, a new framework is proposed to distinguish the cracks. Crack can be distinguished by utilizing optimization techniques based on segmentation. The optimization techniques are Particle Swarm Optimization (PSO), Differential Particle Swarm Optimization (DPSO) and Fractional Order Differential Particle Swarm Optimization (FODPSO). It is important to identify the crack in solar panel cells since they can directly diminish the execution of the panel and additionally the power yield. In view of the segmentation process, the potential regions which have cracks have been found, and then distinctive optimization algorithms were run on these areas to discover crack pixels. An extensive number of trials demonstrate that, this technique procures high accuracy and more complete crack contours with low computation costs

    Low-energy Antiproton Interaction with Helium

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    An ab initio potential for the interaction of the neutral helium atom with antiprotons and protons is calculated using the Born-Oppenheimer approximation. Using this potential, the annihilation cross section for antiprotons in the energy range 0.01 microvolt to 1 eV is calculated.Comment: 13 pages, 7 figures, LaTe

    Theory and applications of atomic and ionic polarizabilities

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    Atomic polarization phenomena impinge upon a number of areas and processes in physics. The dielectric constant and refractive index of any gas are examples of macroscopic properties that are largely determined by the dipole polarizability. When it comes to microscopic phenomena, the existence of alkaline-earth anions and the recently discovered ability of positrons to bind to many atoms are predominantly due to the polarization interaction. An imperfect knowledge of atomic polarizabilities is presently looming as the largest source of uncertainty in the new generation of optical frequency standards. Accurate polarizabilities for the group I and II atoms and ions of the periodic table have recently become available by a variety of techniques. These include refined many-body perturbation theory and coupled-cluster calculations sometimes combined with precise experimental data for selected transitions, microwave spectroscopy of Rydberg atoms and ions, refractive index measurements in microwave cavities, ab initio calculations of atomic structures using explicitly correlated wave functions, interferometry with atom beams, and velocity changes of laser cooled atoms induced by an electric field. This review examines existing theoretical methods of determining atomic and ionic polarizabilities, and discusses their relevance to various applications with particular emphasis on cold-atom physics and the metrology of atomic frequency standards.Comment: Review paper, 44 page

    Genome sequencing and population genomic analyses provide insights into the adaptive landscape of silver birch

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    Silver birch (Betula pendula) is a pioneer boreal tree that can be induced to flower within 1 year. Its rapid life cycle, small (440-Mb) genome, and advanced germplasm resources make birch an attractive model for forest biotechnology. We assembled and chromosomally anchored the nuclear genome of an inbred B. pendula individual. Gene duplicates from the paleohexaploid event were enriched for transcriptional regulation, whereas tandem duplicates were overrepresented by environmental responses. Population resequencing of 80 individuals showed effective population size crashes at major points of climatic upheaval. Selective sweeps were enriched among polyploid duplicates encoding key developmental and physiological triggering functions, suggesting that local adaptation has tuned the timing of and cross-talk between fundamental plant processes. Variation around the tightly-linked light response genes PHYC and FRS10 correlated with latitude and longitude and temperature, and with precipitation for PHYC. Similar associations characterized the growth-promoting cytokinin response regulator ARR1, and the wood development genes KAK and MED5A.Peer reviewe

    Aplicação do movimento kepleriano na orientação de imagens HRC - CBERS 2b

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    Nos últimos 20 anos, pesquisas voltadas ao desenvolvimento de modelos rigorosos para a orientação de sensores orbitais puhbroom lineares vêm sendo desenvolvidas e apresentadas. Na maioria destas pesquisas, a trajetória e a orientação do satélite durante a formação das cenas são obtidas a partir de polinômios de 1º, 2º e até 3º grau. Porém, a atribuição de significado físico aos coeficientes polinomiais indica que o primeiro e o segundo termo se referem à velocidade e a aceleração da plataforma no instante referente à aquisição da primeira linha da cena. Estas quantidades podem ser associadas ao Problema dos Dois Corpos, sendo desenvolvido de acordo com a equação do Movimento Uniformemente Variado. O modelo resultante deste desenvolvimento foi denominado por Michalis e Dowman como Modelo de Kepler. Nesta pesquisa, o Modelo de Kepler é aplicado na orientação de imagens HRC/CBERS 2B e comparado com os modelos que utilizam polinômios para a propagação dos Parâmetros de orientação exterior (POE), amplamente utilizados atualmente. Os resultados obtidos ao comparar o Modelo de Kepler e os modelos polinomiais indicaram que o uso do primeiro modelo permitiu a obtenção de melhores resultados em relação ao segundo

    Diminishing Connectivity Failures by Auto-Reconfiguration in WSN

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    The Wireless Sensor Network is one of the most significant purposes behind the accomplishment of long range wireless communication. Frequent connectivity failures are occurred in the sensor-organised network due to obstruction, snags, message drop because of node energy depletion; obstacle and so forth. The total communication gets collapsed if there any lessening in the nature of correspondence or quality between the sensor nodes or from the sensor nodes to the sink nodes and this prompts to connection failures. To overcome the frequent connectivity failures we propose Diminishing Connectivity Failures by Auto-Reconfiguration in WSN (DCFA). This scheme provides steadfast routes to reduce the connectivity failure and improve the network performance.
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