93,349 research outputs found

    Region of interest-based adaptive multimedia streaming scheme

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    Adaptive multimedia streaming aims at adjusting the transmitted content based on the available bandwidth such as losses that often severely affect the end-user perceived quality are minimized and consequently the transmission quality increases. Current solutions affect equally the whole viewing area of the multimedia frames, despite research showing that there are regions on which the viewers are more interested in than on others. This paper presents a novel region of interest-based adaptive scheme (ROIAS) for multimedia streaming that when performing transmission-related quality adjustments, selectively affects the quality of those regions of the image the viewers are the least interested in. As the quality of the regions the viewers are the most interested in will not change (or will involve little change),the proposed scheme provides higher overall end-user perceived quality than any of the existing adaptive solutions

    Objective assessment of region of interest-aware adaptive multimedia streaming quality

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    Adaptive multimedia streaming relies on controlled adjustment of content bitrate and consequent video quality variation in order to meet the bandwidth constraints of the communication link used for content delivery to the end-user. The values of the easy to measure network-related Quality of Service metrics have no direct relationship with the way moving images are perceived by the human viewer. Consequently variations in the video stream bitrate are not clearly linked to similar variation in the user perceived quality. This is especially true if some human visual system-based adaptation techniques are employed. As research has shown, there are certain image regions in each frame of a video sequence on which the users are more interested than in the others. This paper presents the Region of Interest-based Adaptive Scheme (ROIAS) which adjusts differently the regions within each frame of the streamed multimedia content based on the user interest in them. ROIAS is presented and discussed in terms of the adjustment algorithms employed and their impact on the human perceived video quality. Comparisons with existing approaches, including a constant quality adaptation scheme across the whole frame area, are performed employing two objective metrics which estimate user perceived video quality

    MODIS-HIRIS ground data systems commonality report

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    The High Resolution Imaging Spectrometer (HIRIS) and Moderate Resolution Imaging Spectrometer (MODIS) Data Systems Working Group was formed in September 1988 with representatives of the MODIS Data System Study Group and the HIRIS Project Data System Design Group to collaborate in the development of requirements on the EosDIS necessary to meet the science objectives of the two facility instruments. A major objective was to identify and promote commonality between the HIRIS and MODIS data systems, especially from the science users' point of view. A goal was to provide a base set of joint requirements and specifications which could easily be expanded to a Phase-B representation of the needs of the science users of all EOS instruments. This document describes the points of commonality and difference between the Level-II Requirements, Operations Concepts, and Systems Specifications for the ground data systems for the MODIS and HIRIS instruments at their present state of development

    INFORMATION DOCUMENTS – PRIMORDIAL INSTRUMENTS IN TOURIST COMMUNICATION

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    Tourist information proved to have an important influence on the choice of holiday destinations. An important category of promotional means used tourism as a source of information is a tourist information documents in which graphical advertising has a great importance. In a harmonious combination between an informative text and a picture suggestive of its different forms (flyers, brochures, catalogs, guides and tourist maps, posters and billboards, advertisements in the press) visualize products of interest. This article highlights the importance of tourism information documents on the selection of destination, the requirements and recommendations for their design and the need arrangement advertisement to increase its impact on potential tourists. Tour operators in cooperation with advertising agency, choosing one means of communication and advertising medium itself, according to market research conducted, the production capacity or area of interest to prepare an advertising campaign, the level of tariffs and the type of benefits offered, the type of tourism product offered and the target market segment targeted.promotion, print advertising, advertisement, photo

    An assessment of skill needs in the gas, water and electricity industries

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    Unconventional gas: potential energy market impacts in the European Union

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    In the interest of effective policymaking, this report seeks to clarify certain controversies and identify key gaps in the evidence-base relating to unconventional gas. The scope of this report is restricted to the economic impact of unconventional gas on energy markets. As such, it principally addresses such issues as the energy mix, energy prices, supplies, consumption, and trade flows. Whilst this study touches on coal bed methane and tight gas, its predominant focus is on shale gas, which the evidence at this time suggests will be the form of unconventional gas with the most growth potential in the short- to medium-term. This report considers the prospects for the indigenous production of shale gas within the EU-27 Member States. It evaluates the available evidence on resource size, extractive technology, resource access and market access. This report also considers the implications for the EU of large-scale unconventional gas production in other parts of the world. This acknowledges the fact that many changes in the dynamics of energy supply can only be understood in the broader global context. It also acknowledges that the EU is a major importer of energy, and that it is therefore heavily affected by developments in global energy markets that are largely out of its control.JRC.F.3-Energy securit

    System integration of wind and solar power in Integrated Assessment Models: A cross-model evaluation of new approaches

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    Mitigation-Process Integrated Assessment Models (MP-IAMs) are used to analyze long-term transformation pathways of the energy system required to achieve stringent climate change mitigation targets. Due to their substantial temporal and spatial aggregation, IAMs cannot explicitly represent all detailed challenges of integrating the variable renewable energies (VRE) wind and solar in power systems, but rather rely on parameterized modeling approaches. In the ADVANCE project, six international modeling teams have developed new approaches to improve the representation of power sector dynamics and VRE integration in IAMs. In this study, we qualitatively and quantitatively evaluate the last years' modeling progress and study the impact of VRE integration modeling on VRE deployment in IAM scenarios. For a comprehensive and transparent qualitative evaluation, we first develop a framework of 18 features of power sector dynamics and VRE integration. We then apply this framework to the newly-developed modeling approaches to derive a detailed map of strengths and limitations of the different approaches. For the quantitative evaluation, we compare the IAMs to the detailed hourly-resolution power sector model REMIX. We find that the new modeling approaches manage to represent a large number of features of the power sector, and the numerical results are in reasonable agreement with those derived from the detailed power sector model. Updating the power sector representation and the cost and resources of wind and solar substantially increased wind and solar shares across models: Under a carbon price of 30$/tCO2 in 2020 (increasing by 5% per year), the model-average cost-minimizing VRE share over the period 2050–2100 is 62% of electricity generation, 24%-points higher than with the old model version
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