67,636 research outputs found

    GIS-based approach for assessing the energy potential and the financial feasibility of run-off-river hydro-power in Alpine valleys

    Get PDF
    In the last decade, European attractive policies are favoring the construction of new run-off hydro-power plants. The realization cost of these plants is quite low in mountain areas thanks to small water discharges and high gross heads. For this reason, small rivers have been strongly exploited without considering an optimal use of the resource. Nowadays, available sites are often in areas with low accessibility and a greater specific cost of civil engineering works. However, during the planning of new small hydro-power plants, the dependency of physical, technical, legal and financial variable on space is often not assessed. The tool presented in this paper addresses this gap to support the planning of run-off-river plants. The method improves on previous approaches by (1) integrating all the legal, technical and financial analysis in a GIS tool, and (2) trying to validate the site-specific model with local knowledge. The tool is applied to the Gesso and Vermenagna valleys in the Alps. Information and data were collected and discussed with local stakeholders in order to improve the model results

    Different Approaches to Proof Systems

    Get PDF
    The classical approach to proof complexity perceives proof systems as deterministic, uniform, surjective, polynomial-time computable functions that map strings to (propositional) tautologies. This approach has been intensively studied since the late 70’s and a lot of progress has been made. During the last years research was started investigating alternative notions of proof systems. There are interesting results stemming from dropping the uniformity requirement, allowing oracle access, using quantum computations, or employing probabilism. These lead to different notions of proof systems for which we survey recent results in this paper

    Capital as Artificial Intelligence

    Get PDF
    This article examines science-fictional allegorizations of Soviet-style planned economies, financial markets, autonomous trading algorithms, and global capitalism writ large as nonhuman artificial intelligences, focussing primarily on American science fiction of the Cold War period. Key fictional texts discussed include Star Trek, Isaac Asimov\u27s Machine stories, Terminator, Kurt Vonnegut\u27s Player Piano (1952), Charles Stross\u27s Accelerando (2005), and the short stories of Philip K. Dick. The final section of the article discusses Kim Stanley Robinson\u27s novel 2312 (2012) within the contemporary political context of accelerationist anticapitalism, whose advocates propose working with “the machines” rather than against them

    Can a computer be "pushed" to perform faster-than-light?

    Full text link
    We propose to "boost" the speed of communication and computation by immersing the computing environment into a medium whose index of refraction is smaller than one, thereby trespassing the speed-of-light barrier.Comment: 7 pages, 1 figure, presented at the UC10 Hypercomputation Workshop "HyperNet 10" at The University of Tokyo on June 22, 201

    How to Work with Honest but Curious Judges? (Preliminary Report)

    Get PDF
    The three-judges protocol, recently advocated by Mclver and Morgan as an example of stepwise refinement of security protocols, studies how to securely compute the majority function to reach a final verdict without revealing each individual judge's decision. We extend their protocol in two different ways for an arbitrary number of 2n+1 judges. The first generalisation is inherently centralised, in the sense that it requires a judge as a leader who collects information from others, computes the majority function, and announces the final result. A different approach can be obtained by slightly modifying the well-known dining cryptographers protocol, however it reveals the number of votes rather than the final verdict. We define a notion of conditional anonymity in order to analyse these two solutions. Both of them have been checked in the model checker MCMAS

    Faster Gossiping in Bidirectional Radio Networks with Large Labels

    Full text link
    We consider unknown ad-hoc radio networks, when the underlying network is bidirectional and nodes can have polynomially large labels. For this model, we present a deterministic protocol for gossiping which takes O(nlg2nlglgn)O(n \lg^2 n \lg \lg n) rounds. This improves upon the previous best result for deterministic gossiping for this model by [Gasienec, Potapov, Pagourtizis, Deterministic Gossiping in Radio Networks with Large labels, ESA (2002)], who present a protocol of round complexity O(nlg3nlglgn)O(n \lg^3 n \lg \lg n) for this problem. This resolves open problem posed in [Gasienec, Efficient gossiping in radio networks, SIROCCO (2009)], who cite bridging gap between lower and upper bounds for this problem as an important objective. We emphasize that a salient feature of our protocol is its simplicity, especially with respect to the previous best known protocol for this problem

    Computing Substrates and Life

    No full text
    Alive matter distinguishes itself from inanimate matter by actively maintaining a high degree of inhomogenous organisation. Information processing is quintessential to this capability. The present paper inquires into the degree to which the information processing aspect of living systems can be abstracted from the physical medium of its implementation. Information processing serving to sustain the complex organisation of a living system faces both the harsh reality of real-time requirements and severe constraints on energy and material that can be expended on the task. This issue is of interest for the potential scope of Artificial Life and its interaction with Synthetic Biology. It is pertinent also for information technology. With regard to the latter aspect, the use of a living cell in a robot control architecture is considered

    Technology readiness and segmentation profile of mature consumers

    Get PDF
    Self-service technologies (SSTs) play a major role in enabling consumers to perform service delivery themselves. The purpose of this study was to test extensions of the original Technology Acceptance Model (TAM) aimed at predicting mature consumers’ attitude and behaviour towards using self-service banking technologies (SSBTs). A survey methodology was employed to gather data from 208 mature consumers on variables captured by the extended TAM. Path analysis indicated that self-efficacy, technology discomfort, perceived risk, and personal contact were determinants of perceived ease of use and perceived usefulness and also direct and indirect determinants of attitude towards and intention to use SSBTs. These findings have theoretical implications for models of technology acceptance and practical interventions designed at increasing use of SSBTs among mature consumers
    corecore