A Process for Producing Ice Coverage Marine Information Objects (MIOs) in IHO S-57 Format

While global warming may be opening up more Arctic waters in the summer, ice still infests key shipping lanes in the northern hemisphere during the winter months. To safely navigate these areas, mariners rely on daily ice coverage charts produced by national governmental agencies. Ice charts are primarily issued in paper format or as a fax. However, there is increased interest to ice coverage information on vessel navigation systems such as an Electronic Chart and Display Information Systems (ECDIS). However, to do so, the ice information must be provided as a separate layer of information to the Electronic Navigational Chart (ENC)

Effect of Pions in Cosmic Rays

The effects of pions for vacuum polarization in background magnetic fields are considered. The effects of quark condensates is also briefly addresses. Although these effects are out of the measurement accuracy of laboratory experiments they may be relevant for gamma-ray burst propagation. In particular, for emissions from the center of the galaxy, we show that the mixing between the neutral pion and photons results in a deviation of the gamma-ray spectrum from the standard power-law in the TeV range.Comment: 6 pages, 3 figures; Based in arXiv:0707.4200 with a new very short discussion in qq condensates. To appear in the Proceedings of Scadron'7

Building Capable, Energy-Efficient, Flexible Visualization and Sensing Clusters from Commodity Tablets

We explore the application of clusters of commodity tablet devices to problems spanning a “trilogy” of concerns: visualization, sensing, and computation. We conjecture that such clusters provide a low-cost, energy-efficient, flexible, and ultimately effective platform to tackle a wide range of problems within this trilogy. This is a work in progress, and we now elaborate our position and give a preliminary status report. A wide range of Android tablet devices are available in terms of price and capabilities. “You get what you pay for” w.r.t. display resolution, sensors, and chipset---corresponding to the trilogy. $200 gets one a 1280x800-pixel touch display, quad-core CPU with GPU, and various input sensors (camera, accelerometer, barometer, etc.) When arranged in a suitable geometry, such as a rectangle, such devices form an innovative whole that is more powerful than the sum of its parts, with CPUs and sensors in addition to a much higher combined display resolution than that of conventional HD monitors. Scholarly merit: The tablet cluster serves as a testbed for exploring a wide range of research questions in both technical and application domains. Numerous applications in education and research are imaginable, such as environmental and security monitoring, calculating and visualizing the energy footprint of an organization, facial recognition involving multiple cameras, exploring molecules in three dimensions, visualizing relationships among versions of a text, teaching the color space to art students, mapping audiovisual content from sequential to concurrent playback, etc. Project status: We have made preliminary progress along multiple fronts. Specifically, we have developed an Android/Java prototype app for clustering multiple devices and drawing to the resulting combined virtual display on top of the Skeenzone middleware for distributed mobile applications (http://code.google.com/p/skeenzone). We have also developed a an Android/Scala prototype app for navigating RESTful web services as data sources

Wayfinding and Navigation for People with Disabilities Using Social Navigation Networks

To achieve safe and independent mobility, people usually depend on published information, prior experience, the knowledge of others, and/or technology to navigate unfamiliar outdoor and indoor environments. Today, due to advances in various technologies, wayfinding and navigation systems and services are commonplace and are accessible on desktop, laptop, and mobile devices. However, despite their popularity and widespread use, current wayfinding and navigation solutions often fail to address the needs of people with disabilities (PWDs). We argue that these shortcomings are primarily due to the ubiquity of the compute-centric approach adopted in these systems and services, where they do not benefit from the experience-centric approach. We propose that following a hybrid approach of combining experience-centric and compute-centric methods will overcome the shortcomings of current wayfinding and navigation solutions for PWDs

A Process for Producing Ice Coverage Marine Information Objects (MIOs) in IHO S-57 format

While global warming may be opening up more Arctic waters in the summer, ice still infests key shipping lanes in the northern hemisphere during the winter months. To safely navigate these areas, mariners rely on daily ice coverage charts produced by national governmental agencies. Ice charts are primarily issued in paper format or as a fax. However, there is increased interest to ice coverage information on vessel navigation systems such as an Electronic Chart and Display Information Systems (ECDIS). However, to do so, the ice information must be provided as a separate layer of information to the Electronic Navigational Chart (ENC).Mientras que un calentamiento global puede aumentar la extension de las aguas ârticas en verano, el hieio sigue infestando las dénotas maritimas en el hemisferio septentrional durante los meses de invierno. Para navegar en estas zonas de forma segura, los navegantes conffan en las cartas de cobertura diaria del hielo producidas por agendas gubernamentales nacionales. Las cartas del hielo son editadas principaimente en formato impreso o como fax. Sin embargo, hay un interés creciente por la informaciôn de cobertura del hielo en los sistemas de navegaciôn de los buques, como por ejemplo en los Sistemas de Presentaciôn de las Cartas Electrônicas y de Informaciôn (ECDIS). Sin embargo, para producirlas, tiene que proporcionarse la informaciôn sobre el hielo como una serie de informaciôn separada para la Carta Electrônica de Navegaciôn (ENC).Bien que le réchauffement global puisse faire enfler les eaux arctiques en été, les glaces envahissent toujours les principaux couloirs de navigation dans l'hémisphère, pendant la saison hivernale. Afin de naviguer en toute sécurité dans ces zones, les navigateurs se fient aux cartes des glaces produites quotidiennement par les agences gouvernementales nationales. Les cartes des glaces sont essentiellement communiquées sous forme imprimée ou de télécopie. On note cependant un regain d’intérêt pour les informations sur la couverture des glaces, dans des systèmes de navigation maritime tel que l ’ECDIS (système de visualisation des cartes électroniques et d'information). Toutefois, pour ce faire, les renseignements sur les glaces doivent être transmis, en tant que « niveau » d’information distinct, aux Cartes électroniques de navigation (ENC)

Qualidade dos meios de hospedagem cearenses: um estudo baseado nas avaliações do consumidor evidenciadas no site TripAdvisor

The general objective of this study was to analyze the influence of two attributes of quality of service evidenced by the TripAdvisor website, for general consumer satisfaction. Sample and composed of 43 places in Ceará that participated in the ranking of the most sought after destinations by tourists, and not in Ceará, constituting a total of 2,293 establishments, whose evaluations were captured by a tracker and later extracted with the use of an analyzer, both executed in Python language. The results generated through quantitative methods. The results suggest that investments in the structure of two rooms, the lack of cleaning service, can increase the satisfaction of two customers, considering that these attributes are, respectively, that they are more likely to influence a customer to give top marks to the establishment. Other experts have shown that the majority of the two establishments with the highest marks are located mainly abroad, with emphasis on Jericoacoara, located in the largest and most populous municipalities, least likely to be recognized with the highest overall satisfaction scores, which guests tend to subscribe to more stringent ones such as spending or time, increasing to assign lower overall satisfaction scores.El objetivo general de este estudio fue analizar la influencia de dos atributos de calidad de servicio evidenciados por el sitio web de TripAdvisor, para la satisfacción general del consumidor. Muestra compuesta por 43 localidades en Ceará que participaron en la clasificación de los destinos más buscados por los turistas, y no en Ceará, lo que constituye un total de 2,293 establecimientos, cuyas evaluaciones fueron capturadas por un rastreador y luego extraídas con el uso de un analizador, ambos ejecutados en lenguaje Python. Los resultados generados a través de métodos cuantitativos. Los resultados sugieren que las inversiones en la estructura de dos habitaciones, la falta de servicio de limpieza, puede aumentar la satisfacción de dos clientes, considerando que estos atributos son, respectivamente, que tienen más probabilidades de influir en un cliente para que otorgue las mejores calificaciones al establecimiento. Otros expertos han demostrado que la mayoría de los dos establecimientos con las calificaciones más altas se encuentran principalmente en el extranjero, con énfasis en Jericoacoara, ubicado en los municipios más grandes y poblados, con menos probabilidades de ser reconocido con los puntajes de satisfacción general más altos, que los huéspedes tienden a suscribir a otros más estrictos, como pasar tiempo o tiempo, aumentando para asignar puntajes de satisfacción general más bajos.O objetivo geral do presente estudo é analisar a influência dos atributos da qualidade do serviço evidenciadas pelo site TripAdvisor, na satisfação geral do consumidor. A amostra é composta por 43 localidades cearenses que participam do ranking de destinos mais procurados pelos turistas no Ceará, constituindo um total de 2.293 estabelecimentos, cujas avaliações foram capturadas por um crawler e, em seguida, extraídas com uso de um parser, ambos executados em linguagem Python. Os resultados gerados por meio de métodos quantitativos. Os resultados sugerem que investimentos na estrutura dos quartos, no atendimento e na limpeza poderiam aumentar a satisfação dos clientes, tendo em vista que são esses atributos, respectivamente, que têm a maior probabilidade de influenciar um cliente a atribuir nota máxima ao estabelecimento. Outros achados mostram que a maioria dos estabelecimentos avaliados com nota máxima estão localizados principalmente no litoral, com destaque para os de Jericoacoara, que hospedagens situadas em municípios mais extensos e populosos têm, em média, menos chances de serem avaliadas com notas máximas de satisfação geral, que os hóspedes tendem a ficar mais rigorosos com o passar o tempo, levando a atribuir notas menores de satisfação geral

Superconductivity from spin fluctuations and long-range interactions in magic-angle twisted bilayer graphene

Magic-angle twisted bilayer graphene (MATBG) has been extensively explored both theoretically and experimentally as a suitable platform for a rich and tunable phase diagram that includes ferromagnetism, charge order, broken symmetries, and unconventional superconductivity. In this work, we investigate the intricate interplay between long-range electron-electron interactions, spin fluctuations, and superconductivity in MATBG. By employing a low-energy model for MATBG that captures the correct shape of the flat bands, we explore the effects of short- and long-range interactions on spin fluctuations and their impact on the superconducting (SC) pairing vertex in the Random Phase Approximation (RPA). We find that the SC state is notably influenced by the strength of long-range Coulomb interactions. Interestingly, our RPA calculations indicate that there is a regime where the system can traverse from a magnetic phase to the SC phase by \emph{increasing} the relative strength of long-range interactions compared to the on-site ones. These findings underscore the relevance of electron-electron interactions in shaping the intriguing properties of MATBG and offer a pathway for designing and controlling its SC phase.Comment: 9 pages, 5 figure

Efficient Strategies for Graph Pattern Mining Algorithms on GPUs

Graph Pattern Mining (GPM) is an important, rapidly evolving, and computation demanding area. GPM computation relies on subgraph enumeration, which consists in extracting subgraphs that match a given property from an input graph. Graphics Processing Units (GPUs) have been an effective platform to accelerate applications in many areas. However, the irregularity of subgraph enumeration makes it challenging for efficient execution on GPU due to typical uncoalesced memory access, divergence, and load imbalance. Unfortunately, these aspects have not been fully addressed in previous work. Thus, this work proposes novel strategies to design and implement subgraph enumeration efficiently on GPU. We support a depth-first search style search (DFS-wide) that maximizes memory performance while providing enough parallelism to be exploited by the GPU, along with a warp-centric design that minimizes execution divergence and improves utilization of the computing capabilities. We also propose a low-cost load balancing layer to avoid idleness and redistribute work among thread warps in a GPU. Our strategies have been deployed in a system named DuMato, which provides a simple programming interface to allow efficient implementation of GPM algorithms. Our evaluation has shown that DuMato is often an order of magnitude faster than state-of-the-art GPM systems and can mine larger subgraphs (up to 12 vertices).Comment: Accepted for publication on IEEE 34th International Symposium on Computer Architecture and High Performance Computing (SBAC-PAD'22