13,750 research outputs found

    Pollicott's Algorithm for Markovian Products of Positive Matrices

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    In a recent paper by M. Pollicott, an efficient algorithm was proposed, applying Ruelle's theory of transfer operators and Grothendieck's classical work on nuclear operators, to compute the Lyapunov exponent associated with the i.i.d. products of positive matrices. In this article, we generalise the result to Markovian products and correct some minor mistakes in Pollicott's original paper.Comment: 27 page

    Environmental modelling of the Chief Information Officer

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    Since the introduction of the term in the 1980’s, the role of the Chief Information Officer (CIO) has been widely researched. Various perceptions and dimensions of the role have been explored and debated. However, the explosion in data proliferation (and the inevitable resulting information fuelled change) further complicates organisational expectations of the CIOs role. If organisations are to competitively exploit the digital trend, then those charged with recruiting and developing CIOs now need to be more effective in determining (and shaping) CIO traits and attributes, within the context of their own organisational circumstances and in line with stakeholder expectations. CIOs also need to determine their own suitability and progression within their chosen organisation if they are to remain motivated and effective. Before modelling the role of the future CIO, it is necessary to synthesise our current knowledge (and the lessons learnt) about the CIO. This paper, therefore, aims to identify and summate the spectrum of key researched ‘themes’ pertaining to the role of the CIO. Summating previous research, themes are modelled around four key CIO ‘dimensions’, namely (1) Impacting factors, (2) Controlling factors (3) Responses and (4) CIO ‘attributes’. Having modelled the CIOs current environment, and recognising the evolving IT enabled information landscape, the authors call for further research to inform the recruitment and development of the future CIO in terms of personal attributes and the measurable impact such attributes will have on their respective organisation

    Philanthropy in the News

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    Over the last two decades, the quantity of news coverage of foundations has gradually risen, but its quality remains highly superficial, according to this report by Philanthropy Awareness Initiative and University of Minnesota professor David Fan. In fact, nearly 99% of more than 40,000 stories since 1990 have been transactional in their content -- focused on grants made and dollars out the door, not on benefits achieved

    Differential Dynamic Programming for time-delayed systems

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    Trajectory optimization considers the problem of deciding how to control a dynamical system to move along a trajectory which minimizes some cost function. Differential Dynamic Programming (DDP) is an optimal control method which utilizes a second-order approximation of the problem to find the control. It is fast enough to allow real-time control and has been shown to work well for trajectory optimization in robotic systems. Here we extend classic DDP to systems with multiple time-delays in the state. Being able to find optimal trajectories for time-delayed systems with DDP opens up the possibility to use richer models for system identification and control, including recurrent neural networks with multiple timesteps in the state. We demonstrate the algorithm on a two-tank continuous stirred tank reactor. We also demonstrate the algorithm on a recurrent neural network trained to model an inverted pendulum with position information only.Comment: 7 pages, 6 figures, conference, Decision and Control (CDC), 2016 IEEE 55th Conference o

    Public investment and poverty reduction in Tanzania

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    "Using Tanzania as a test case, this study demonstrates how household survey data can be used to assess the impacts of public investments on growth and poverty. A two step procedure is used. First, household survey data are used to link household welfare measures to human capital and household access to infrastructure and technology, while controlling for other community and household characteristics. The second step links household human capital and access to infrastructure and technology to past public investments in these factors. As in the Asian studies, the growth effects (measured as per capita income) of investments in agricultural research, roads, and education are found to be large. But unlike Asia, no clear distinction emerges between the measured impacts for high and low potential areas. In many high potential areas, returns to investments are still high and there is no sign of any diminishing marginal returns. This suggests that there has been insufficient public investment in all kinds of regions. Nevertheless, the results show that there is opportunity to improve on the growth and poverty impacts of total public investment through better regional targeting of specific types of investment. For example, additional investments in rural education have attractive growth and poverty impacts in all regions, whereas additional investments in roads and agricultural research are better spent in the central and southern regions of the country." Authors' AbstractHuman capital ,Agricultural research Africa ,Public Expenditures, Investment, and Finance ,Infrastructures ,Welfare and Poverty ,
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