229,366 research outputs found
Cloud Based IoT Architecture
The Internet of Things (IoT) and cloud computing have grown in popularity over the past decade as the internet becomes faster and more ubiquitous. Cloud platforms are well suited to handle IoT systems as they are accessible and resilient, and they provide a scalable solution to store and analyze large amounts of IoT data. IoT applications are complex software systems and software developers need to have a thorough understanding of the capabilities, limitations, architecture, and design patterns of cloud platforms and cloud-based IoT tools to build an efficient, maintainable, and customizable IoT application. As the IoT landscape is constantly changing, research into cloud-based IoT platforms is either lacking or out of date. The goal of this thesis is to describe the basic components and requirements for a cloud-based IoT platform, to provide useful insights and experiences in implementing a cloud-based IoT solution using Microsoft Azure, and to discuss some of the shortcomings when combining IoT with a cloud platform
Simplifying the Development, Use and Sustainability of HPC Software
Developing software to undertake complex, compute-intensive scientific
processes requires a challenging combination of both specialist domain
knowledge and software development skills to convert this knowledge into
efficient code. As computational platforms become increasingly heterogeneous
and newer types of platform such as Infrastructure-as-a-Service (IaaS) cloud
computing become more widely accepted for HPC computations, scientists require
more support from computer scientists and resource providers to develop
efficient code and make optimal use of the resources available to them. As part
of the libhpc stage 1 and 2 projects we are developing a framework to provide a
richer means of job specification and efficient execution of complex scientific
software on heterogeneous infrastructure. The use of such frameworks has
implications for the sustainability of scientific software. In this paper we
set out our developing understanding of these challenges based on work carried
out in the libhpc project.Comment: 4 page position paper, submission to WSSSPE13 worksho
Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini
We present an updated analysis of Jupiter's equatorial meteorology from
Cassini observations. For two months preceding the spacecraft's closest
approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the
atmosphere. We created time-lapse movies from this period in order to analyze
the dynamics of equatorial hot spots and their interactions with adjacent
latitudes. Hot spots are quasi-stable, rectangular dark areas on
visible-wavelength images, with defined eastern edges that sharply contrast
with surrounding clouds, but diffuse western edges serving as nebulous
boundaries with adjacent equatorial plumes. Hot spots exhibit significant
variations in size and shape over timescales of days and weeks. Some of these
changes correspond with passing vortex systems from adjacent latitudes
interacting with hot spots. Strong anticyclonic gyres present to the south and
southeast of the dark areas appear to circulate into hot spots. Impressive,
bright white plumes occupy spaces in between hot spots. Compact cirrus-like
'scooter' clouds flow rapidly through the plumes before disappearing within the
dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s
hot spot and plume drift speed. This raises the possibility that the scooter
clouds may be more illustrative of the actual jet stream speed at these
latitudes. Most previously published zonal wind profiles represent the drift
speed of the hot spots at their latitude from pattern matching of the entire
longitudinal image strip. If a downward branch of an equatorially-trapped
Rossby waves controls the overall appearance of hot spots, however, the
westward phase velocity of the wave leads to underestimates of the true jet
stream speed.Comment: 33 pages, 11 figures; accepted for publication in Icarus; for
supplementary movies, please contact autho
An Integrated Approach for Characterizing Aerosol Climate Impacts and Environmental Interactions
Aerosols exert myriad influences on the earth's environment and climate, and on human health. The complexity of aerosol-related processes requires that information gathered to improve our understanding of climate change must originate from multiple sources, and that effective strategies for data integration need to be established. While a vast array of observed and modeled data are becoming available, the aerosol research community currently lacks the necessary tools and infrastructure to reap maximum scientific benefit from these data. Spatial and temporal sampling differences among a diverse set of sensors, nonuniform data qualities, aerosol mesoscale variabilities, and difficulties in separating cloud effects are some of the challenges that need to be addressed. Maximizing the long-term benefit from these data also requires maintaining consistently well-understood accuracies as measurement approaches evolve and improve. Achieving a comprehensive understanding of how aerosol physical, chemical, and radiative processes impact the earth system can be achieved only through a multidisciplinary, inter-agency, and international initiative capable of dealing with these issues. A systematic approach, capitalizing on modern measurement and modeling techniques, geospatial statistics methodologies, and high-performance information technologies, can provide the necessary machinery to support this objective. We outline a framework for integrating and interpreting observations and models, and establishing an accurate, consistent, and cohesive long-term record, following a strategy whereby information and tools of progressively greater sophistication are incorporated as problems of increasing complexity are tackled. This concept is named the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON). To encompass the breadth of the effort required, we present a set of recommendations dealing with data interoperability; measurement and model integration; multisensor synergy; data summarization and mining; model evaluation; calibration and validation; augmentation of surface and in situ measurements; advances in passive and active remote sensing; and design of satellite missions. Without an initiative of this nature, the scientific and policy communities will continue to struggle with understanding the quantitative impact of complex aerosol processes on regional and global climate change and air quality
MODIS: Moderate Resolution Imaging Spectrometer
This brochure describes the Moderate Resolution Imaging Spectrometer (MODIS) instrument on NASA's Terra satellite. The first NASA Earth Observing System (EOS) satellite, Terra, was launched on December 18, 1999, carrying five remote sensors. The most comprehensive EOS sensor is MODIS which offers a unique combination of features: it detects a wide spectral range of electromagnetic energy; it takes measurements at three spatial resolutions (levels of detail); it takes measurements all day, every day; and it has a wide field of view. This continual, comprehensive coverage allows MODIS to complete an electromagnetic picture of the globe every two days. Educational levels: Undergraduate lower division, Undergraduate upper division, Graduate or professional, Informal education
Lighting in the third dimension : laser scanning as an architectural survey and representation method
This paper proposes tridimensional (3D) laser scanning to architects and lighting designers as a lighting
enquiry and visualization method for existing built environments. The method constitutes a complement
to existing lighting methods by responding to limitations of photometric measurements, computer
simulation and HDR imagery in surveying and visualizing light in actual buildings. The research explores
advantages and limitations of 3D laser scanning in a case study addressing a vast, geometrically complex
and fragmented naturally and artificially lit space. Lighting patterns and geometry of the case study are
captured with a 3D laser scanner through a series of four scans. A single 3D model of the entire space is
produced from the aligned and fused scans. Lighting distribution patterns are showcased in relation to
the materiality, geometry and position of windows, walls, lighting fixtures and day lighting sources.
Results and presented through images similar to architectural presentation drawings. More specifically,
the lighting distribution patterns are illustrated in a floor plan, a reflected ceiling plan, an axonometry
and a cross-section. The point cloud model of the case study is also generated into a video format
representing the entire building as well as different viewpoints. The study shows that the proposed
method provides powerful visualization results due to the unlimited number of images that can be
generated from a point cloud and facilitates understanding of existing lighting conditions in spaces
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