1,817 research outputs found

    Preliminary Candidate Advanced Avionics System (PCAAS)

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    Specifications which define the system functional requirements, the subsystem and interface needs, and other requirements such as maintainability, modularity, and reliability are summarized. A design definition of all required avionics functions and a system risk analysis are presented

    Compressed Data Structures for Dynamic Sequences

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    We consider the problem of storing a dynamic string SS over an alphabet Σ={1,,σ}\Sigma=\{\,1,\ldots,\sigma\,\} in compressed form. Our representation supports insertions and deletions of symbols and answers three fundamental queries: access(i,S)\mathrm{access}(i,S) returns the ii-th symbol in SS, ranka(i,S)\mathrm{rank}_a(i,S) counts how many times a symbol aa occurs among the first ii positions in SS, and selecta(i,S)\mathrm{select}_a(i,S) finds the position where a symbol aa occurs for the ii-th time. We present the first fully-dynamic data structure for arbitrarily large alphabets that achieves optimal query times for all three operations and supports updates with worst-case time guarantees. Ours is also the first fully-dynamic data structure that needs only nHk+o(nlogσ)nH_k+o(n\log\sigma) bits, where HkH_k is the kk-th order entropy and nn is the string length. Moreover our representation supports extraction of a substring S[i..i+]S[i..i+\ell] in optimal O(logn/loglogn+/logσn)O(\log n/\log\log n + \ell/\log_{\sigma}n) time

    Inequality of happiness in nations

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    The first comparison of happiness in nations took place in 1948 and involved 9 countries (Buchanan, 1953). A second comparative study in 1960 covered 14 nations (Cantril 1965) and this was followed by a global survey in 1975 carried out by Gallup (1976), in which happiness in all parts of the world was assessed. Today we have comparable data on happiness in 90 nations and for a dozen nations we also have time series of 40 to 25 years (Veenhoven 2004). These data provide the fuel for a rising number of publications on happiness in nations. Currently, the Bibliography of Happiness counts some 400 entries on this subject, 20% of which have been published over the last 5 years. To date, all the studies have been focused on the level of happiness in nations, that is, on how happy citizens are in a country. In this special issue we look at the same data from a different perspective and focus on difference in happiness in nations, that is, on the degree of divergence with regard to happiness found among citizens in a particular country

    Efficient Representation of Multidimensional Data over Hierarchical Domains

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-46049-9_19[Abstract] We consider the problem of representing multidimensional data where the domain of each dimension is organized hierarchically, and the queries require summary information at a different node in the hierarchy of each dimension. This is the typical case of OLAP databases. A basic approach is to represent each hierarchy as a one-dimensional line and recast the queries as multidimensional range queries. This approach can be implemented compactly by generalizing to more dimensions the k2k2 -treap, a compact representation of two-dimensional points that allows for efficient summarization queries along generic ranges. Instead, we propose a more flexible generalization, which instead of a generic quadtree-like partition of the space, follows the domain hierarchies across each dimension to organize the partitioning. The resulting structure is much more efficient than a generic multidimensional structure, since queries are resolved by aggregating much fewer nodes of the tree.Ministerio de Economía, Industria y Competitividad; TIN2013-46238-C4-3-RMinisterio de Economía, Industria y Competitividad; IDI-20141259Ministerio de Economía, Industria y Competitividad; ITC-20151305Ministerio de Economía y Competitividad; ITC-20151247Xunta de Galicia; GRC2013/053Chile.Fondo Nacional de Desarrollo Científico y Tecnológico; 1-140796COST. IC130

    Sceptical Employees as CSR Ambassadors in Times of Financial Uncertainty

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    This chapter offers new insights into the understanding of internal (employee) perceptions of organizational corporate social responsibility (CSR) policies and strategies. This study explores the significance of employees’ involvement and scepticism upon CSR initiatives and focuses on the effects it may have upon word of mouth (WOM) and the development of employee–organisation relationships. Desk research introduces the research questions. Data for the research questions were gathered through a self-completion questionnaire distributed in a hardcopy form to the sample. An individual’s level of scepticism and involvement appears to affect the development of a positive effect on employees’ WOM. Involvement with the domain of the investment may be a central factor affecting relationship building within the organization, and upon generation of positive WOM. The chapter offers a conceptual framework to public relations (PR) and corporate communications practitioners, which may enrich their views and understanding of the use and value of CSR for communication strategies and practices. For-profit organisations are major institutions in today’s society. CSR is proffered as presenting advantages for (at macro level) society and (micro level) the organization and its employees. Concepts, such as involvement and scepticism, which have not been rigorously examined in PR and corporate communication literature, are addressed. By examining employee perceptions, managers and academic researchers gain insights into the acceptance, appreciation and effectiveness of CSR policies and activities upon the employee stakeholder group. This will affect current and future CSR communication strategies. The knowledge acquired from this chapter may be transferable outside the for-profit sector

    Effects of broadening and electron overheating in tunnel structures based on metallic clusters

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    We study the influence of energy levels broadening and electron subsystem overheating in island electrode (cluster) on current-voltage characteristics of three-electrode structure. A calculation scheme for broadening effect in one-dimensional case is suggested. Estimation of broadening is performed for electron levels in disc-like and spherical gold clusters. Within the two-temperature model of metallic cluster and by using a size dependence of the Debye frequency the effective electron temperature as a function of bias voltage is found approximately. We suggest that the effects of broadening and electron overheating are responsible for the strong smoothing of current-voltage curves, which is observed experimentally at low temperatures in structures based on clusters consisting of accountable number of atoms.Comment: 8 pages, 5 figure

    Reading, Trauma and Literary Caregiving 1914-1918: Helen Mary Gaskell and the War Library

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    This article is about the relationship between reading, trauma and responsive literary caregiving in Britain during the First World War. Its analysis of two little-known documents describing the history of the War Library, begun by Helen Mary Gaskell in 1914, exposes a gap in the scholarship of war-time reading; generates a new narrative of "how," "when," and "why" books went to war; and foregrounds gender in its analysis of the historiography. The Library of Congress's T. W. Koch discovered Gaskell's ground-breaking work in 1917 and reported its successes to the American Library Association. The British Times also covered Gaskell's library, yet researchers working on reading during the war have routinely neglected her distinct model and method, skewing the research base on war-time reading and its association with trauma and caregiving. In the article's second half, a literary case study of a popular war novel demonstrates the extent of the "bitter cry for books." The success of Gaskell's intervention is examined alongside H. G. Wells's representation of textual healing. Reading is shown to offer sick, traumatized and recovering combatants emotional and psychological caregiving in ways that she could not always have predicted and that are not visible in the literary/historical record

    Modular Linear-Drive Cryocooler Electronics

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    Presented at the 16th International Cryocooler Conference, held May 17-20, 2008 in Atlanta, Georgia.The Modular Advanced Cryocooler Electronics (MACE) system developed at Iris Technology Corporation combines configurable, high-power motor drives with precision telemetry capability in a design that is amenable to radiation hardening. A Telemetry Aggregation Unit (TAU) located near the cryocooler minimizes attenuation and contamination of sensitive cryocooler feedback by digitizing sensor data locally for transmission back to the controller, while multiple 500 W drive channels in the Main Control Unit (MCU) supply power waveforms at up to 95% efficiency. The modular design concept allows for adding drive cards in the event that additional channels are required or removing drive cards to reduce size, weight, and power. The TAU incorporates up to 14 external sensors with an aggregate data rate of up to 800,000 samples per second, dynamically allocated to any combination of telemetry by the control software. A low cost version of the electronics can be realized by populating with commercial components, or by utilizing an alternate control scheme to reduce the cost of radiation-hard controller components. A brassboard demonstration was performed at Raytheon in which the High Capacity RSP2 (HC-RSP2) cryocooler was driven, with temperature and vibration control loops closed at high power and low cryogenic temperatures. This paper discusses the MACE development, testing, and lessons learned
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