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Area Coverage (area + coverage)
Selected AbstractsMethods for retrieving hydrologically significant surface parameters from remote sensing: a review for applications to east Asia regionHYDROLOGICAL PROCESSES, Issue 4 2009Bunkei Matsushita Abstract As human populations and resource use continue to increase, water quality and water resource management will become major problems. With its advantages of large area coverage, high spatial resolution, frequent update and consistent quality, remote sensing has been widely used for hydrological studies and water resources management. This paper focuses on three potential functions of remote sensing for hydrological analysis in east Asia: (1) monitoring water quality in turbid lakes; (2) extracting impervious surface areas (ISAs) from watersheds and (3) estimating evapotranspiration in semi-arid areas. Reviewing the results of the above three topics, it becomes clear that the ability of the current remote sensing technique is still limited in terms of its use in hydrological simulations. An alternative to improving the sensors is developing effective algorithms to compensate for the limitations of current satellite sensors. Copyright © 2008 John Wiley & Sons, Ltd. [source] Surface Selective Deposition of PMMA on Layered Double Hydroxide Nanocrystals Immobilized on Solid Substrates,ADVANCED MATERIALS, Issue 5 2009Jong Hyeon Lee A novel nanostructured hybrid PMMA/MgAl-LDH thin film enables a strong UV-blocking effect, up to 97% below 300,nm, and excellent visible transparency. The graft density of PMMA films can be controlled by adjusting the area coverage of immobilized LDH monolayer with a highly-orientated structure on oxide, metal, and polymer substrates. [source] Pinpointing users with location estimation techniques and Wi-Fi hotspot technologyINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 5 2008Kevin Curran Location awareness is becoming an important capability for mobile computing; however, it has not been possible until now to provide cheap pervasive positioning systems. Wide area coverage is most famously achieved by using global positioning systems (GPS). A constellation of low-orbit satellites cover the earth's surface. Unfortunately GPS does not work indoors and has limited success in big cities because of the ,urban canyon' effect. PlaceLab is a research project that attempts to solve the ubiquity issues surrounding 802.11-based location estimation. PlaceLab, like RADAR, uses a device's 802.11 interface; however, it does not require the area to be pre-calibrated. It predicts location via the known positions of the access points detected by the device. Commonly used systems have a number of drawbacks, including cost, accuracy and the ability to work indoors. PlaceLab is a piece of open source software developed by Intel Research that can pinpoint a user within a Wi-Fi network. We set out here to investigate whether PlaceLab can be used as a means of establishing a user's position. This type of investigation could, if successful, pave the way for the development of other location-based applications. This report documents the efforts to answer the above question. PlaceLab was found to work, but only in ideal locations where factors such as the number of floors and the lack of available APs did not affect its use. It was concluded that these factors prevent the system from being effective as a means of establishing a user's position in most locations on campus. Copyright © 2008 John Wiley & Sons, Ltd. [source] A survey on mobile satellite systemsINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 1 2010Paolo Chini Abstract Satellite systems represent a significant solution to provide communication services to mobile users in under-populated regions, in emergency areas, on planes, trains, and ships. In all these cases, satellite systems have unique capabilities in terms of robustness, wide area coverage, and broadcast/multicast capabilities. This paper surveys current mobile satellite networks and services from different standpoints, encompassing research issues, recent standardization advances (e.g. mobile extension for DVB-S2/-RCS, DVB-SH) and some operational systems (e.g. Globalstar, Inmarsat BGAN, Iridium, and Thuraya). The last part of this paper is devoted to qualitative and quantitative comparisons of the different mobile satellite systems to understand their characteristics in terms of services, capacity, resource utilization efficiency, and user mobility degree.Copyright © 2009 John Wiley & Sons, Ltd. [source] Overview of the DVB-SH specificationsINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 4-5 2009Philip Kelley Abstract This article provides an overview of the DVB-SH specifications, and the context within which they have been developed. The main DVB-SH configurations are introduced, with explanations of both the technical and frequency planning considerations that drive choices. Regulatory aspects in the European Union and United States of America are summarized. Then specific DVB-SH issues are being addressed, involving reception conditions and channel characteristics, combining techniques for satellite and terrestrial signals, and synchronization and local content insertion. Some attention is paid to the reuse of DVB link and application layer features. Finally, a couple of likely service introduction scenarios are suggested. It is claimed that DVB-SH fulfills the initial requirements of extending the present UHF-based service offer to other frequencies below 3,GHz with a large area coverage, a reduced total network infrastructure cost and an expansion of the offer in terms of number of TV channels or multimedia services. Copyright © 2009 John Wiley & Sons, Ltd. [source] Explaining the global pattern of protected area coverage: relative importance of vertebrate biodiversity, human activities and agricultural suitabilityJOURNAL OF BIOGEOGRAPHY, Issue 8 2008Colby Loucks Abstract Aim, Twelve per cent of the Earth's terrestrial surface is covered by protected areas, but neither these areas nor the biodiversity they contain are evenly distributed spatially. To guide future establishment of protected areas, it is important to understand the factors that have shaped the spatial arrangement of the current protected area system. We used an information-theoretic approach to assess the ability of vertebrate biodiversity measures, resource consumption and agricultural potential to explain the global coverage pattern of protected areas. Location, Global. Methods, For each of 762 World Wildlife Fund terrestrial ecoregions of the world, we measured protected area coverage, resource consumption, terrestrial vertebrate species richness, number of endemic species, number of threatened species, net primary production, elevation and topographic heterogeneity. We combined these variables into 39 a priori models to describe protected area coverage at the global scale, and for six biogeographical realms. Using the Akaike information criterion and Akaike weights, we identified the relative importance and influence of each variable in describing protected area coverage. Results, Globally, the number of endemic species was the best variable describing protected area coverage, followed by the number of threatened species. Species richness and resource consumption were of moderate importance and agricultural potential had weak support for describing protected area coverage at a global scale. Yet, the relative importance of these factors varied among biogeographical realms. Measures of vertebrate biodiversity (species richness, endemism and threatened species) were among the most important variables in all realms, except the Indo-Malayan, but had a wide range of relative importance and influence. Resource consumption was inversely related to protected area coverage across all but one realm (the Palearctic), most strongly in the Nearctic realm. Agricultural potential, despite having little support in describing protected area coverage globally, was strongly and positively related to protection in the Palearctic and Neotropical realms, as well as in the Indo-Malayan realm. The Afrotropical, Indo-Malayan and Australasian realms showed no clear, strong relationships between protected area coverage and the independent variables. Main conclusions, Globally, the existing protected area network is more strongly related to biodiversity measures than to patterns of resource consumption or agricultural potential. However, the relative importance of these factors varies widely among the world's biogeographical realms. Understanding the biases of the current protected area system may help to correct for them as future protected areas are added to the global network. [source] Adhesion of pancreatic beta cells to biopolymer filmsBIOPOLYMERS, Issue 8 2009S. Janette Williams Abstract Dramatic reversal of Type 1 diabetes in patients receiving pancreatic islet transplants continues to prompt vigorous research concerning the basic mechanisms underlying patient turnaround. At the most fundamental level, transplanted islets must maintain viability and function in vitro and in vivo and should be protected from host immune rejection. Our previous reports showed enhancement of islet viability and insulin secretion per tissue mass for small islets (<125 ,m) as compared with large islets (>125 ,m), thus, demonstrating the effect of enhancing the mass transport of islets (i.e. increasing tissue surface area to volume ratio). Here, we report the facile dispersion of rat islets into individual cells that are layered onto the surface of a biopolymer film towards the ultimate goal of improving mass transport in islet tissue. The tightly packed structure of intact islets was disrupted by incubating in calcium-free media resulting in fragmented islets, which were further dispersed into individual or small groups of cells by using a low concentration of papain. The dispersed cells were screened for adhesion to a range of biopolymers and the nature of cell adhesion was characterized for selected groups by quantifying adherent cells, measuring the surface area coverage of the cells, and immunolabeling cells for adhesion proteins interacting with selected biopolymers. Finally, beta cells in suspension were centrifuged to form controlled numbers of cell layers on films for future work determining the mass transport limitations in the adhered tissue constructs. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 676,685, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | ||||||||||