47,510 research outputs found

    Thermal power systems small power systems applications project. Decision analysis for evaluating and ranking small solar thermal power system technologies. Volume 1: A brief introduction to multiattribute decision analysis

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    The principal concepts of the Keeney and Raiffa approach to multiattribute decision analysis are described. Topics discussed include the concepts of decision alternatives, outcomes, objectives, attributes and their states, attribute utility functions, and the necessary independence properties for the attribute states to be aggregated into a numerical representation of the preferences of the decision maker for the outcomes and decision alternatives

    Optimal Portfolio Management in Alaska: A Case Study on Risk Characteristics of Environmental Consulting Companies

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    A Project Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in Project ManagementSharp declines in global oil prices have led to a marked contraction in Alaska’s natural resource dependent economy. This, coupled with record the State’s budgetary shortfalls and a decrease in incoming federal dollars, has created a climate where environmental consulting companies must accept riskier projects to balance portfolio growth and security. As a result, companies must adopt a risk-based portfolio management approach as both a high level strategy and a core management practice. It is important to specifically identify projects best suited for an organization’s tolerance for risk based off of the supply and demand of the industry in rapidly changing economic conditions. Therefore, the aims of this project report are to help environmental consulting companies identify risk characteristics and manage their portfolio, as well as develop a tool to guide decision-making and selecting projects best suited for a companies’ portfolio strategy. The results of this research may provide Alaska based environmental companies with a clear understanding of the types of projects that offer both development and financial security for an organization. This research paper will present the methodology, results, and an environmental consulting portfolio management tool.Title Page / Table of Contents / List of Exhibits / Abstract / Introduction / Background / Literature Review / Project Methodology / Research Methodology / Presentation and Analysis of Data from Survey / Data Validation From Survey / Conclusion / Recommendation / Project Conclusion / Recommendations for Further Research / References / Appendi

    Balancing contractual and relational approaches for PPP success and sustainability

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    Useful synergies are targeted by proposing a convergence of hitherto parallel international endeavours towards: (1) developing better and sustainable relationships for more productive construction project teams, in general; and (2) optimising the necessarily long term contractual arrangements of PPPs in particular. Examples are drawn from Africa and Latin America to reinforce reported PPP experiences from other regions, in building up a case for injecting ‘relational contracting approaches’ in order to develop more productive and sustainable PPPs. Strong and sustainable relationships are shown to be essential, and complementary to appropriate contractual incentives, that would together empower PPP project teams to focus on developing sustainable infrastructure and ultimately on overall sustainable development. These propositions are merged into a basic model that merits further investigation and development, in order to ensure that planned PPPs benefit the community at large, in respect of both present and future generations

    From Iconic Design to Lost Luggage: Innovation at Heathrow Terminal 5

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    This paper aims to contribute to understanding of how organizations respond to risk and uncertainty by combining and balancing routines and innovation. It shows how approaches to risk and uncertainty are shaped by the contractual framework in large multi-party projects. The paper addresses a gap in the literature on how risk and uncertainty is managed to deliver innovation in large-scale ‘megaprojects’. These megaprojects are notorious for high rates of failure that conventionally evoke organizational strategies avoiding risks and uncertainties. Yet strategies for managing risk and uncertainty are essential to the routines and innovation that overcome the challenges of successfully delivering large-scale, complex projects.

    Requirements: The Key to Sustainability

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    Software's critical role in society demands a paradigm shift in the software engineering mind-set. This shift's focus begins in requirements engineering. This article is part of a special issue on the Future of Software Engineering

    Galaxy Zoo: CANDELS barred discs and bar fractions

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    The formation of bars in disc galaxies is a tracer of the dynamical maturity of the population. Previous studies have found that the incidence of bars in discs decreases from the local Universe to z ~ 1, and by z > 1 simulations predict that bar features in dynamically mature discs should be extremely rare. Here, we report the discovery of strong barred structures in massive disc galaxies at z ~ 1.5 in deep rest-frame optical images from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey. From within a sample of 876 disc galaxies identified by visual classification in Galaxy Zoo, we identify 123 barred galaxies. Selecting a subsample within the same region of the evolving galaxy luminosity function (brighter than L*), we find that the bar fraction across the redshift range 0.5 ≀ z ≀ 2 (fbar = 10.7+6.3 -3.5 per cent after correcting for incompleteness) does not significantly evolve.We discuss the implications of this discovery in the context of existing simulations and our current understanding of the way disc galaxies have evolved over the last 11 billion yearsPeer reviewedFinal Accepted Versio

    Dynamical Analysis of Nearby ClustErs. Automated astrometry from the ground: precision proper motions over wide field

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    The kinematic properties of the different classes of objects in a given association hold important clues about its member's history, and offer a unique opportunity to test the predictions of the various models of stellar formation and evolution. DANCe (standing for Dynamical Analysis of Nearby ClustErs) is a survey program aimed at deriving a comprehensive and homogeneous census of the stellar and substellar content of a number of nearby (<1kpc) young (<500Myr) associations. Whenever possible, members will be identified based on their kinematics properties, ensuring little contamination from background and foreground sources. Otherwise, the dynamics of previously confirmed members will be studied using the proper motion measurements. We present here the method used to derive precise proper motion measurements, using the Pleiades cluster as a test bench. Combining deep wide field multi-epoch panchromatic images obtained at various obervatories over up to 14 years, we derive accurate proper motions for the sources present in the field of the survey. The datasets cover ~80 square degrees, centered around the Seven Sisters. Using new tools, we have computed a catalog of 6116907 unique sources, including proper motion measurements for 3577478 of them. The catalogue covers the magnitude range between i=12~24mag, achieving a proper motion accuracy <1mas/yr for sources as faint as i=22.5mag. We estimate that our final accuracy reaches 0.3mas/yr in the best cases, depending on magnitude, observing history, and the presence of reference extragalactic sources for the anchoring onto the ICRS.Comment: Accepted for publication in A&
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