253 research outputs found

    Comparing persistence diagrams through complex vectors

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    The natural pseudo-distance of spaces endowed with filtering functions is precious for shape classification and retrieval; its optimal estimate coming from persistence diagrams is the bottleneck distance, which unfortunately suffers from combinatorial explosion. A possible algebraic representation of persistence diagrams is offered by complex polynomials; since far polynomials represent far persistence diagrams, a fast comparison of the coefficient vectors can reduce the size of the database to be classified by the bottleneck distance. This article explores experimentally three transformations from diagrams to polynomials and three distances between the complex vectors of coefficients.Comment: 11 pages, 4 figures, 2 table

    Multi-mode TES bolometer optimization for the LSPE-SWIPE instrument

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    In this paper we explore the possibility of using transition edge sensor (TES) detectors in multi-mode configuration in the focal plane of the Short Wavelength Instrument for the Polarization Explorer (SWIPE) of the balloon-borne polarimeter Large Scale Polarization Explorer (LSPE) for the Cosmic Microwave Background (CMB) polarization. This study is motivated by the fact that maximizing the sensitivity of TES bolometers, under the augmented background due to the multi-mode design, requires a non trivial choice of detector parameters. We evaluate the best parameter combination taking into account scanning strategy, noise constraints, saturation power and operating temperature of the cryostat during the flight.Comment: in Journal of Low Temperature Physics, 05 January 201

    Graphic-based concept retrieval

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    Two ways of expressing concepts in the context of image retrieval are presented. One, Keypics, is on the side of an image owner, who wants the image itself to be found on the Web; the second, Trittico, is on the side of the image searcher. Both are based on the paradigm of human intermediation for overcoming the semantic gap. Both require tools capable of qualitative analysis, and have been experimented by using persistent homology

    Estudio taxonómico preliminar de la ficoflora planctónica en la zona aluvial del Río Colorado (La Pampa, Argentina)

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    This work is part of a larger project on the study of algal biodiversity of a lotic system in La Pampa province. In this first stage we analyze the algal flora of samples collected during the summer season and autumn of 2010. The study area is located in the floodplain of the Colorado River, the natural boundary between the provinces of La Pampa and Río Negro at its intersection with Provincial Route 11 (Department Lihuel Calel). The methodology used in the collection followed the standard parameters for lotic environments. The samples were fixed with 4% formaldehyde and deposited in the herbarium of the Faculty of Agronomy (UNLPam) under the symbol SRFA. The preliminary results of the algal flora of summer and autumn shows 64 taxa, of which 26.5% corresponds to Cyanophyceae, 36% to Chlorophyceae and Bacillariophyceae, and 1.5% to Dinophyceae. During the summer the class Chlorophyceae species contributed 40% and fall did the Bacillariophyceae with 43.7%. The 37.5% of the registered species were common to both seasons.Instituto de Limnología "Raúl A. Ringuelet

    Estudio taxonómico preliminar de la ficoflora planctónica en la zona aluvial del Río Colorado (La Pampa, Argentina)

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    This work is part of a larger project on the study of algal biodiversity of a lotic system in La Pampa province. In this first stage we analyze the algal flora of samples collected during the summer season and autumn of 2010. The study area is located in the floodplain of the Colorado River, the natural boundary between the provinces of La Pampa and Río Negro at its intersection with Provincial Route 11 (Department Lihuel Calel). The methodology used in the collection followed the standard parameters for lotic environments. The samples were fixed with 4% formaldehyde and deposited in the herbarium of the Faculty of Agronomy (UNLPam) under the symbol SRFA. The preliminary results of the algal flora of summer and autumn shows 64 taxa, of which 26.5% corresponds to Cyanophyceae, 36% to Chlorophyceae and Bacillariophyceae, and 1.5% to Dinophyceae. During the summer the class Chlorophyceae species contributed 40% and fall did the Bacillariophyceae with 43.7%. The 37.5% of the registered species were common to both seasons.Instituto de Limnología "Raúl A. Ringuelet

    Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

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    El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares.The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

    Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

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    El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares.The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

    Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

    Get PDF
    El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares.The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA
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