Evaluation of a Change Detection Methodology by Means of Binary Thresholding Algorithms and Informational Fusion Processes

Landcover is subject to continuous changes on a wide variety of temporal and spatial scales. Those changes produce significant effects in human and natural activities. Maintaining an updated spatial database with the occurred changes allows a better monitoring of the Earth?s resources and management of the environment. Change detection (CD) techniques using images from different sensors, such as satellite imagery, aerial photographs, etc., have proven to be suitable and secure data sources from which updated information can be extracted efficiently, so that changes can also be inventoried and monitored. In this paper, a multisource CD methodology for multiresolution datasets is applied. First, different change indices are processed, then different thresholding algorithms for change/no_change are applied to these indices in order to better estimate the statistical parameters of these categories, finally the indices are integrated into a change detection multisource fusion process, which allows generating a single CD result from several combination of indices. This methodology has been applied to datasets with different spectral and spatial resolution properties. Then, the obtained results are evaluated by means of a quality control analysis, as well as with complementary graphical representations. The suggested methodology has also been proved efficiently for identifying the change detection index with the higher contribution.

La barrera del análisis estructural y la representación gráfica en el desarrollo de los proyectos arquitectónicos: el caso de la Ópera de Sidney

En numerosas ocasiones a lo largo de la historia la imaginación de los creadores ha ido por delante de las posibilidades técnicas de cada momento. Así, muchas de estas nuevas ideas han requerido largos periodos de tiempo para materializarse como realidad construida, hasta que el desarrollo tecnológico e industrial hubo alcanzado un grado de madurez suficiente. En el campo de la arquitectura, estas limitaciones técnicas se han ido acotando paulatinamente hasta desembocar en la situación actual en la que cualquier planteamiento formal puede ser representado gráficamente y analizado desde un punto de vista estructural, superádose de este modo la barrera existente históricamente en el tratamiento de las formas. A lo largo del presente tesis doctoral se analiza cómo la formulación del Método de los Elementos Finitos en la década de los cincuenta y las curvas de Bézier en la década de los sesenta del siglo pasado y la posterior generalización de los ordenadores personales y de los programas informáticos asociados (C.A.D. y F.E.M. principalmente) en los estudios de arquitectura e ingeniería a partir de la década de los noventa, posibilitó el desarrollo de cualquier propuesta arquitectónica, por compleja que ésta fuese, provocando una verdadera revolución a nivel formal en el mundo de la arquitectura, especialmente en el campo de la edificación singular o icónica. Se estudia este proceso a través de ocho edificios; cuatro anteriores y otros tantos posteriores a la desaparición de la barrera anteriormente referida, establecida de forma simbólica en la década de los años ochenta del siglo XX: Frontón de Recoletos en Madrid, Edificio Seagram en Nueva York, Habitat ’67 en Montreal, Ópera de Sídney, museo Guggenheim de Bilbao, ampliación del Victoria & Albert Museum en Londres, tanatorio “Meiso no Mori” en Gifu y nueva sede de la CCTV en Pekín. De entre ellos, la Ópera de Sídney, obra del arquitecto danés Jørn Utzon, condensa gran parte de los aspectos relevantes investigados en relación a la influencia que los métodos de representación y análisis estructural ejercen en la concepción y construcción de las obras de arquitectura. Por este motivo y por considerarse un hito de la arquitectura a nivel global se toma como caso de estudio. La idea general del edificio, que data de 1956, se enmarca en una época inmediatamente anterior a la del desarrollo científico y tecnológico anteriormente referido. Esta ausencia de herramientas de diseño disponibles acordes a la complejidad formal de la propuesta planteada condicionó enormente la marcha del proyecto, dilatándose dramáticamente en el tiempo y disparándose su coste hasta el punto de que el propio arquitecto danés fue separado de las obras antes de su conclusión. Además, la solución estructural finalmente construida de las cubiertas dista mucho de la prevista por Utzon inicialmente. Donde él había imaginado unas finas láminas de hormigón flotando sobre el paisaje se materializó una estructura más pesada, formada por costillas pretensadas de hormigón con unas secciones notablemente mayores. La forma también debió ser modificada de modo ostensible respecto a la propuesta inicial. Si este edificio se pretendiese construir en la actualidad, con toda seguridad el curso de los acontecimientos se desarrollaría por senderos muy diferentes. Ante este supuesto, se plantean las siguientes cuestiones: ¿sería posible realizar un análisis estructural de la cubierta laminar planteada por Utzon inicialmente en el concurso con las herramientas disponibles en la actualidad?; ¿sería dicha propuesta viable estructuralmente?. A lo largo de las siguientes páginas se pretende dar respuesta a estas cuestiones, poniendo de relieve el impacto que los ordenadores personales y los programas informáticos asociados han tenido en la manera de concebir y construir edificios. También se han analizado variantes a la solución laminar planteada en la fase de concurso, a través de las cuales, tratando en la medida de lo posible de ajustarse a las sugerencias que Ove Arup y su equipo realizaron a Jørn Utzon a lo largo del dilatado proceso de proyecto, mejorar el comportamiento general de la estructura del edificio. Por último, se ha pretendido partir de cero y plantear, desde una perspectiva contemporánea, posibles enfoques metodológicos aplicables a la búsqueda de soluciones estructurales compatibles con la forma propuesta originalmente por Utzon para las cubiertas de la Ópera de Sídney y que nunca llegó a ser construida (ni analizada), considerando para ello los medios tecnológicos, científicos e industriales disponibles en la actualidad. Abstract On numerous occasions throughout history the imagination of creators has gone well beyond of the technical possibilities of their time. Many new ideas have required a long period to materialize, until the technological and industrial development had time to catch up. In the architecture field, these technical limitations have gradually tightened leading to the current situation in which any formal approach can be represented and analyzed from a structural point of view, thus concluding that the structural analysis and the graphical representation’s barrier in the development of architectural projects has dissappeared. Throughout the following pages it is examined how the development of the Finite Element Method in the fifties and the Bezier curves in the sixties of the last century and the subsequent spread of personal computers and specialized software in the architectural and engineering offices from the nineties, enabled the development of any architectural proposal independently of its complexity. This has caused a revolution at a formal level in architecture, especially in the field of iconic building. This process is analyzed through eight buildings, four of them before and another four after the disappearance of the above mentioned barrier, roughly established in the eighties of the last century: Fronton Recoletos in Madrid, Seagram Building in New York Habitat '67 in Montreal, Sydney Opera House, Guggenheim Museum Bilbao, Victoria & Albert Museum extension in London, Crematorium “Meiso no Mori” in Gifu and the new CCTV headquarters in Beijing. Among them, the Sydney Opera House, designed by Danish architect Jørn Utzon, condenses many of the main aspects previously investigated regarding the impact of representation methods and structural analysis on the design and construction of architectural projects. For this reason and also because it is considered a global architecture milestone, it is selected as a case study. The building’s general idea, which dates from 1956, is framed at a time immediately preceding the above mentioned scientific and technological development. This lack of available design tools in accordance with the proposal’s formal complexity conditioned enormously the project’s progress, leading to a dramatic delay and multiplying the final budget disproportionately to the point that the Danish architect himself was separated from the works before completion. Furthermore, the built structure differs dramatically from the architect’s initial vision. Where Utzon saw a thin concrete shell floating over the landscape a heavier structure was built, consisting of prestressed concrete ribs with a significantly greater size. The geometry also had to be modified. If this building were to built today, the course of events surely would walk very different paths. Given this assumption, a number of questions could then be formulated: Would it be possible to perform a structural analysis of Utzon’s initially proposed competition-free-ways roof’s geometry with the tools available nowadays?; Would this proposal be structurally feasable?. Throughout the following pages it is intended to clarify this issues, highlighting personal computers and associated software’s impact in building design and construction procedures, especially in the field of iconic building. Variants have also been analyzed for the laminar solution proposed in the competition phase, through which, trying as far as possible to comply with the suggestions that Ove Arup and his team did to Jørn Utzon along the lengthy process project, improving the overall performance of the building structure. Finally, we have started from scratch and analyzed, from a contemporary perspective, possible structural solutions compatible with Utzon’s Opera House’s original geometry and vision –proposal that was never built (nor even analyzed)-, taking into consideration the technological, scientific and industrial means currently available.

The Zebrafish Information Network (ZFIN): a resource for genetic, genomic and developmental research

The Zebrafish Information Network, ZFIN, is a WWW community resource of zebrafish genetic, genomic and developmental research information (http://zfin.org). ZFIN provides an anatomical atlas and dictionary, developmental staging criteria, research methods, pathology information and a link to the ZFIN relational database (http://zfin.org/ZFIN/). The database, built on a relational, object-oriented model, provides integrated information about mutants, genes, genetic markers, mapping panels, publications and contact information for the zebrafish research community. The database is populated with curated published data, user submitted data and large dataset uploads. A broad range of data types including text, images, graphical representations and genetic maps supports the data. ZFIN incorporates links to other genomic resources that provide sequence and ortholog data. Zebrafish nomenclature guidelines and an automated registration mechanism for new names are provided. Extensive usability testing has resulted in an easy to learn and use forms interface with complex searching capabilities.

Visibilidad de las revistas latinoamericanas de Bibliotecología y Ciencia de la información a través de Google Scholar

Las revistas académico-científicas son uno de los principales canales de comunicación y difusión de los resultados de investigación. Sin embargo no todas tienen el mismo prestigio y grado de influencia en la comunidad científica. De su calidad y visibilidad dependen, en gran medida, las posibilidades de que un trabajo sea conocido, leído y citado. Esta investigación se propone determinar la visibilidad en Google Scholar de un conjunto de revistas latinoamericanas de Bibliotecología y Ciencia de la Información, y clasificarlas según su grado de visibilidad. Utilizando la aplicación Publish or Perish para recuperar las citas de las revistas se calcularon indicadores basados en la citación. Se combinaron técnicas de análisis multivariado de datos para realizar agrupamientos de revistas según su grado de visibilidad, y se elaboraron representaciones gráficas que facilitan la interpretación de los resultados y la identificación de los grupos de revistas con alta, media y baja visibilidad

Visibilidad de las revistas latinoamericanas de Bibliotecología y Ciencia de la información a través de Google Scholar

Las revistas académico-científicas son uno de los principales canales de comunicación y difusión de los resultados de investigación. Sin embargo no todas tienen el mismo prestigio y grado de influencia en la comunidad científica. De su calidad y visibilidad dependen, en gran medida, las posibilidades de que un trabajo sea conocido, leído y citado. Esta investigación se propone determinar la visibilidad en Google Scholar de un conjunto de revistas latinoamericanas de Bibliotecología y Ciencia de la Información, y clasificarlas según su grado de visibilidad. Utilizando la aplicación Publish or Perish para recuperar las citas de las revistas se calcularon indicadores basados en la citación. Se combinaron técnicas de análisis multivariado de datos para realizar agrupamientos de revistas según su grado de visibilidad, y se elaboraron representaciones gráficas que facilitan la interpretación de los resultados y la identificación de los grupos de revistas con alta, media y baja visibilidad

Visibilidad de las revistas latinoamericanas de Bibliotecología y Ciencia de la información a través de Google Scholar

Las revistas académico-científicas son uno de los principales canales de comunicación y difusión de los resultados de investigación. Sin embargo no todas tienen el mismo prestigio y grado de influencia en la comunidad científica. De su calidad y visibilidad dependen, en gran medida, las posibilidades de que un trabajo sea conocido, leído y citado. Esta investigación se propone determinar la visibilidad en Google Scholar de un conjunto de revistas latinoamericanas de Bibliotecología y Ciencia de la Información, y clasificarlas según su grado de visibilidad. Utilizando la aplicación Publish or Perish para recuperar las citas de las revistas se calcularon indicadores basados en la citación. Se combinaron técnicas de análisis multivariado de datos para realizar agrupamientos de revistas según su grado de visibilidad, y se elaboraron representaciones gráficas que facilitan la interpretación de los resultados y la identificación de los grupos de revistas con alta, media y baja visibilidad

A study in the application of domestic solar assisted heat pumps for heating and cooling

In the present work, the more important parameters of the heat pump system and of solar assisted heat pump systems were analysed in a quantitative way. Ideal and real Rankine cycles applied to the heat pump, with and without subcooling and superheating were studied using practical recommended values for their thermodynamics parameters. Comparative characteristics of refrigerants here analysed looking for their applicability in heat pumps for domestic heating and their effect in the performance of the system. Curves for the variation of the coefficient of performance as a function of condensing and evaporating temperatures were prepared for R12. Air, water and earth as low-grade heat sources and basic heat pump design factors for integrated heat pumps and thermal stores and for solar assisted heat pump-series, parallel and dual-systems were studied. The analysis of the relative performance of these systems demonstrated that the dual system presents advantages in domestic applications. An account of energy requirements for space and hater heating in the domestic sector in the O.K. is presented. The expected primary energy savings by using heat pumps to provide for the heating demand of the domestic sector was found to be of the order of 7%. The availability of solar energy in the U.K. climatic conditions and the characteristics of the solar radiation here studied. Tables and graphical representations in order to calculate the incident solar radiation over a tilted roof were prepared and are given in this study in section IV. In order to analyse and calculate the heating load for the system, new mathematical and graphical relations were developed in section V. A domestic space and water heating system is described and studied. It comprises three main components: a solar radiation absorber, the normal roof of a house, a split heat pump and a thermal store. A mathematical study of the heat exchange characteristics in the roof structure was done. This permits to evaluate the energy collected by the roof acting as a radiation absorber and its efficiency. An indication of the relative contributions from the three low-grade sources: ambient air, solar boost and heat loss from the house to the roof space during operation is given in section VI, together with the average seasonal performance and the energy saving for a prototype system tested at the University of Aston. The seasonal performance as found to be 2.6 and the energy savings by using the system studied 61%. A new store configuration to reduce wasted heat losses is also discussed in section VI.

Eigenfunctions and fundamental solutions of the Caputo fractional Laplace and Dirac operators

In this paper, by using the method of separation of variables, we obtain eigenfunctions and fundamental solutions for the three parameter fractional Laplace operator defined via fractional Caputo derivatives. The solutions are expressed using the Mittag-Leffler function and we show some graphical representations for some parameters. A family of fundamental solutions of the corresponding fractional Dirac operator is also obtained. Particular cases are considered in both cases.

Hierarchical clustering with multiple-height branch-cut applied to short time-series gene expression data.

Rigid adherence to pre-specified thresholds and static graphical representations can lead to incorrect decisions on merging of clusters. As an alternative to existing automated or semi-automated methods, we developed a visual analytics approach for performing hierarchical clustering analysis of short time-series gene expression data. Dynamic sliders control parameters such as the similarity threshold at which clusters are merged and the level of relative intra-cluster distinctiveness, which can be used to identify "weak-edges" within clusters. An expert user can drill down to further explore the dendrogram and detect nested clusters and outliers. This is done by using the sliders and by pointing and clicking on the representation to cut the branches of the tree in multiple-heights. A prototype of this tool has been developed in collaboration with a small group of biologists for analysing their own datasets. Initial feedback on the tool has been positive.

OriDB: a DNA replication origin database

Replication of eukaryotic chromosomes initiates at multiple sites called replication origins. Replication origins are best understood in the budding yeast Saccharomyces cerevisiae, where several complementary studies have mapped their locations genome-wide. We have collated these datasets, taking account of the resolution of each study, to generate a single list of distinct origin sites. OriDB provides a web-based catalogue of these confirmed and predicted S.cerevisiae DNA replication origin sites. Each proposed or confirmed origin site appears as a record in OriDB, with each record comprising seven pages. These pages provide, in text and graphical formats, the following information: genomic location and chromosome context of the origin site; time of origin replication; DNA sequence of proposed or experimentally confirmed origin elements; free energy required to open the DNA duplex (stress-induced DNA duplex destabilization or SIDD); and phylogenetic conservation of sequence elements. In addition, OriDB encourages community submission of additional information for each origin site through a User Notes facility. Origin sites are linked to several external resources, including the Saccharomyces Genome Database (SGD) and relevant publications at PubMed. Finally, a Chromosome Viewer utility allows users to interactively generate graphical representations of DNA replication data genome-wide. OriDB is available at www.oridb.org.

Advancing Bag-of-visual-words Representations For Lesion Classification In Retinal Images.

Diabetic Retinopathy (DR) is a complication of diabetes that can lead to blindness if not readily discovered. Automated screening algorithms have the potential to improve identification of patients who need further medical attention. However, the identification of lesions must be accurate to be useful for clinical application. The bag-of-visual-words (BoVW) algorithm employs a maximum-margin classifier in a flexible framework that is able to detect the most common DR-related lesions such as microaneurysms, cotton-wool spots and hard exudates. BoVW allows to bypass the need for pre- and post-processing of the retinographic images, as well as the need of specific ad hoc techniques for identification of each type of lesion. An extensive evaluation of the BoVW model, using three large retinograph datasets (DR1, DR2 and Messidor) with different resolution and collected by different healthcare personnel, was performed. The results demonstrate that the BoVW classification approach can identify different lesions within an image without having to utilize different algorithms for each lesion reducing processing time and providing a more flexible diagnostic system. Our BoVW scheme is based on sparse low-level feature detection with a Speeded-Up Robust Features (SURF) local descriptor, and mid-level features based on semi-soft coding with max pooling. The best BoVW representation for retinal image classification was an area under the receiver operating characteristic curve (AUC-ROC) of 97.8% (exudates) and 93.5% (red lesions), applying a cross-dataset validation protocol. To assess the accuracy for detecting cases that require referral within one year, the sparse extraction technique associated with semi-soft coding and max pooling obtained an AUC of 94.2 ± 2.0%, outperforming current methods. Those results indicate that, for retinal image classification tasks in clinical practice, BoVW is equal and, in some instances, surpasses results obtained using dense detection (widely believed to be the best choice in many vision problems) for the low-level descriptors.

Síndrome do X Frágil com variante de Dandy-Walker: estudo clínico das manifestações comunicativas orais e escritas

A síndrome do X Frágil é a causa mais frequente de deficiência intelectual hereditária. A variante de Dandy-Walker trata-se de uma constelação específica de achados neurorradiológicos. Este estudo relata achados da comunicação oral e escrita de um menino de 15 anos com diagnóstico clínico e molecular da síndrome do X-Frágil e achados de neuroimagem do encéfalo compatíveis com variante de Dandy-Walker. A avaliação fonoaudiológica foi realizada por meio da Observação do Comportamento Comunicativo, aplicação do ABFW - Teste de Linguagem Infantil - Fonologia, Perfil de Habilidades Fonológicas, Teste de Desempenho Escolar, Teste Illinois de Habilidades Psicolinguísticas, avaliação do sistema estomatognático e avaliação audiológica. Observou-se: alteração de linguagem oral quanto às habilidades fonológicas, semânticas, pragmáticas e morfossintáticas; déficits nas habilidades psicolinguísticas (recepção auditiva, expressão verbal, combinação de sons, memória sequencial auditiva e visual, closura auditiva, associação auditiva e visual); e alterações morfológicas e funcionais do sistema estomatognático. Na leitura verificou-se dificuldades na decodificação dos símbolos gráficos e na escrita havia omissões, aglutinações e representações múltiplas com o uso predominante de vogais e dificuldades na organização viso-espacial. Em matemática, apesar do reconhecimento numérico, não realizou operações aritméticas. Não foram observadas alterações na avaliação audiológica periférica. A constelação de sintomas comportamentais, cognitivos, linguísticos e perceptivos, previstos na síndrome do X-Frágil, somada às alterações estruturais do sistema nervoso central, pertencentes à variante de Dandy-Walker, trouxeram interferências marcantes no desenvolvimento das habilidades comunicativas, no aprendizado da leitura e escrita e na integração social do indivíduo.

Coloured Petri nets and graphical simulation for the validation of a robotic cell in aircraft industry

This paper proposes a mixed validation approach based on coloured Petri nets and 3D graphic simulation for the design of supervisory systems in manufacturing cells with multiple robots. The coloured Petri net is used to model the cell behaviour at a high level of abstraction. It models the activities of each cell component and its coordination by a supervisory system. The graphical simulation is used to analyse and validate the cell behaviour in a 3D environment, allowing the detection of collisions and the calculation of process times. The motivation for this work comes from the aeronautic industry. The automation of a fuselage assembly process requires the integration of robots with other cell components such as metrological or vision systems. In this cell, the robot trajectories are defined by the supervisory system and results from the coordination of the cell components. The paper presents the application of the approach for an aircraft assembly cell under integration in Brazil. This case study shows the feasibility of the approach and supports the discussion of its main advantages and limits. (C) 2011 Elsevier Ltd. All rights reserved.

On state representations of nonlinear implicit systems

This work considers a semi-implicit system A, that is, a pair (S, y), where S is an explicit system described by a state representation (x)over dot(t) = f(t, x(t), u(t)), where x(t) is an element of R(n) and u(t) is an element of R(m), which is subject to a set of algebraic constraints y(t) = h(t, x(t), u(t)) = 0, where y(t) is an element of R(l). An input candidate is a set of functions v = (v(1),.... v(s)), which may depend on time t, on x, and on u and its derivatives up to a Finite order. The problem of finding a (local) proper state representation (z)over dot = g(t, z, v) with input v for the implicit system Delta is studied in this article. The main result shows necessary and sufficient conditions for the solution of this problem, under mild assumptions on the class of admissible state representations of Delta. These solvability conditions rely on an integrability test that is computed from the explicit system S. The approach of this article is the infinite-dimensional differential geometric setting of Fliess, Levine, Martin, and Rouchon (1999) (`A Lie-Backlund Approach to Equivalence and Flatness of Nonlinear Systems`, IEEE Transactions on Automatic Control, 44(5), (922-937)).

On state representations of time-varying nonlinear systems

This work considers a nonlinear time-varying system described by a state representation, with input u and state x. A given set of functions v, which is not necessarily the original input u of the system, is the (new) input candidate. The main result provides necessary and sufficient conditions for the existence of a local classical state space representation with input v. These conditions rely on integrability tests that are based on a derived flag. As a byproduct, one obtains a sufficient condition of differential flatness of nonlinear systems. (C) 2009 Elsevier Ltd. All rights reserved.