135,179 research outputs found

    Forecasting Popularity of Videos using Social Media

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    This paper presents a systematic online prediction method (Social-Forecast) that is capable to accurately forecast the popularity of videos promoted by social media. Social-Forecast explicitly considers the dynamically changing and evolving propagation patterns of videos in social media when making popularity forecasts, thereby being situation and context aware. Social-Forecast aims to maximize the forecast reward, which is defined as a tradeoff between the popularity prediction accuracy and the timeliness with which a prediction is issued. The forecasting is performed online and requires no training phase or a priori knowledge. We analytically bound the prediction performance loss of Social-Forecast as compared to that obtained by an omniscient oracle and prove that the bound is sublinear in the number of video arrivals, thereby guaranteeing its short-term performance as well as its asymptotic convergence to the optimal performance. In addition, we conduct extensive experiments using real-world data traces collected from the videos shared in RenRen, one of the largest online social networks in China. These experiments show that our proposed method outperforms existing view-based approaches for popularity prediction (which are not context-aware) by more than 30% in terms of prediction rewards

    Alaska Correctional Requirements: A Forecast of Prison Population through the Year 2000

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    This report is part of the Fire Island Prison Feasibility Study, a project conducted jointly by the School of Justice and School of Engineering at University of Alaska, Anchorage under contract to the Alaska Department of Corrections. The project undertook to assess the feasibility of locating a correctional facility on a 4,240 acre tract of land on Fire Island, which lies in Upper Cook Inlet about three miles off Point Campbell within the Municipality of Anchorage. The project was divided into three major phases: (1) an assessment of future bed space needs of the Alaska Department of Corrections; (2) an evaluation of the physical site and cost estimates for prison construction and operation; and (3) a public opinion survey and open discussion.The growth of the Alaska prison inmate population over the past fifteen years has been substantial. According to available statistics there were 482 institutionalized adult prisoners under control of the Alaska Division of Corrections in January 1971; by January 1980 this population had increased to 770 inmates; and between 1980 and 1985, the number of Alaska inmates almost tripled, rising from 770 to 2,073. Accurate forecasts of the future size and makeup of the prison population are needed as a basis for long-range programs and capital planning. This report presents long and short-term forecasts of the Alaska incarcerated prisoner population and bedspace needs of the Alaska Department of Corrections through the year 2000. The forecasts were developed by taking into consideration historical facts and status quo assumptions. Attention is also given to the impact of the 1980 Alaska criminal code revision on unsentenced and sentenced populations. The forecast derived from this study provides evidence of the need for additional institutional capacity in Southcentral Alaska by 1990. Planning should proceed for a capacity of 1,000 beds to be available for use by 1990.Alaska Department of CorrectionsAcknowledgments / Summary of Study / I. Introduction / II. Long-Range Forecasts / III. Short-Range Forecasts / IV. Regional Forecasts / V. Conclusions / APPENDICES / A. Inmate Population Forecasting: Statistical Model / B. JUSSIM Forecasting Model / C. Bibliography of Inmate Population Forecastin

    A review of physical supply and EROI of fossil fuels in China

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    This paper reviews China’s future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China’s total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found

    Futures Research: A New Perspective for Corporate Planning

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