35,254 research outputs found

    A Wikipedia Literature Review

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    This paper was originally designed as a literature review for a doctoral dissertation focusing on Wikipedia. This exposition gives the structure of Wikipedia and the latest trends in Wikipedia research

    FM contract relationships: from mobilisation to sustainable partnership

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    Purpose / theory Outsourcing is a fundamental business model for the Facilities Management (FM) industry. To enable sustained mutual success the parties involved must seek to understand the unique, socially constructed, and often highly complex situational realities of the organisational ecologies they are engaged in. The FM industry can unlock improved performance and strategic credibility through an appreciation of the need for different conversations. Design / methodology / approach Findings from two recent cases are considered. Data from two different client-contractor relationship situations was collected utilising a critical ethnographic research methodology; a phenomenological paradigm that acknowledges knowledge as socially constructed through language. A variant on Scott-Morgan‟s unwritten-rules coding method was used to analyse the data and justify the prevalent themes and issues presented. Findings Findings include the role of perceptions and assertions in the construction of social realities, change management implications, and how these impact on the traditional view of the client/contractor relationship. Ethnographic findings are typically context specific, therefore generalisations must be carefully considered. The key findings are however substantiated by existing FM outsourcing literature. Originality / value Highlights the practical importance of seeking to understand socially embedded realities for improved FM contract performance. Considers the human resource element of change via FM outsourcing. Takes a social constructivist approach to organisational sense-making. Uses examples from focused, critical ethnographies to explore existing FM contracting dynamics. Qualitative investigations into related organisational circumstances are encouraged to further develop an evidence base

    Proxy and self-report agreement on the Stroke and Aphasia Quality of Life Scale-39

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    Background and purpose: Health related quality of life outcomes are increasingly used to measure the effectiveness of stroke interventions. People with severe aphasia after stroke may be unable to self-report on such measures, necessitating the use of proxy respondents. We explored the level of agreement between people with aphasia (PWA) and their proxies on the Stroke and Aphasia Quality of Life Scale (SAQOL-39) and whether this agreement is influenced by demographic variables and proxy levels of depression and carer strain. Methods: People with chronic aphasia (≥6 months post stroke) were recruited through the UK national charity for PWA. They were interviewed on the SAQOL-39 and their nominated proxies were interviewed on the SAQOL-39, the General Health Questionnaire and the Caregiver Strain Index. Proxy respondents had to be ≥18 years of age, see the person with aphasia at least twice a week and have no known severe mental health problems or cognitive decline. Results: 50 of 55 eligible pairs (91%) took part in the study. Proxies rated PWA as more severely affected than PWA rated themselves. The SDs of the difference scores were large and the difference was significant for three of the four SAQOL-39 domains and the overall mean (p≤0.01). However, the bias as indicated by effect sizes was small to moderate (0.2–0.5). The strength of the agreement was excellent for the overall SAQOL-39 and the physical domain (intra-class correlation coefficient ICC 0.8), good for the psychosocial and communication domains (0.7) and fair for the energy domain (0.5). Demographic variables and proxy’s mood and carer strain did not affect the level of agreement. Conclusions: For group comparisons, proxy respondents who are in frequent contact with people with chronic aphasia can reliably report on their health related quality of life, using the SAQOL-39. Although there are significant differences between PWA and proxy responses, the magnitude of this difference is small to moderate

    Frameworks, Symmetry and Rigidity

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    Symmetry equations are obtained for the rigidity matrix of a bar-joint framework in R^d. These form the basis for a short proof of the Fowler-Guest symmetry group generalisation of the Calladine-Maxwell counting rules. Similar symmetry equations are obtained for the Jacobian of diverse framework systems, including constrained point-line systems that appear in CAD, body-pin frameworks, hybrid systems of distance constrained objects and infinite bar-joint frameworks. This leads to generalised forms of the Fowler-Guest character formula together with counting rules in terms of counts of symmetry-fixed elements. Necessary conditions for isostaticity are obtained for asymmetric frameworks, both when symmetries are present in subframeworks and when symmetries occur in partition-derived frameworks.Comment: 5 Figures. Replaces Dec. 2008 version. To appear in IJCG

    Correct ordering in the Zipf-Poisson ensemble

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    We consider a Zipf--Poisson ensemble in which X_i\sim\poi(Ni^{-\alpha}) for α>1\alpha>1 and N>0N>0 and integers i1i\ge 1. As NN\to\infty the first n(N)n'(N) random variables have their proper order X1>X2>...>XnX_1>X_2>...>X_{n'} relative to each other, with probability tending to 1 for nn' up to (AN/log(N))1/(α+2)(AN/\log(N))^{1/(\alpha+2)} for an explicit constant A(α)3/4A(\alpha)\ge 3/4. The rate N1/(α+2)N^{1/(\alpha+2)} cannot be achieved. The ordering of the first n(N)n'(N) entities does not preclude Xm>XnX_m>X_{n'} for some interloping m>nm>n'. The first n"n" random variables are correctly ordered exclusive of any interlopers, with probability tending to 1 if n"(BN/log(N))1/(α+2)n"\le (BN/\log(N))^{1/(\alpha+2)} for B<AB<A. For a Zipf--Poisson model of the British National Corpus, which has a total word count of 100,000,000100{,}000{,}000, our result estimates that the 72 words with the highest counts are properly ordered

    Short-term effect of soil disturbance by mechanical weeding on plant available nutrients in an organic vs conventional rotations experiment

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    The question whether soil disturbance from mechanical weeding in organic systems affects nutrient release from organic matter in compost-amended soil was examined in a long-term organic-versus-conventional rotational cropping system experiment over three years. The experimental design included continuous snap beans, and a fully phased snap beans/fall rye crop rotation sequence. Treatments were combinations of yearly applied fertiliser (synthetic fertiliser, 1× compost, 3× compost) and weed control (herbicide, mechanical weeding). The 1× compost rate was calculated to deliver the equivalent of 50 kg N ha-1: equal to the rate ofN in the synthetic fertiliser treatments. Ion exchange membranes were buried for 24 hours following mechanical weeding in bean plots. Adsorbed ions were then eluted and quantified. Available ammonium-nitrogen was not affected byweeding treatment, but nitrate-nitrogen was consistently less in mechanically weeded plots than in plots treated with herbicide. Principal component analysis of NH4-N, NO3-N, P, K, Ca and Mg availabilities showed distinct groupings of treatments according to fertility treatment rather than weeding treatment. The effect of cropping sequence on available nutrients was pronounced (P ≤ 0.001) only in plots amended with synthetic fertilisers

    Robust gradient-based discrete-time iterative learning control algorithms

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    This paper considers the use of matrix models and the robustness of a gradient-based Iterative Learning Control (ILC) algorithm using both fixed learning gains and gains derived from parameter optimization. The philosophy of the paper is to ensure monotonic convergence with respect to the mean square value of the error time series. The paper provides a complete and rigorous analysis for the systematic use of matrix models in ILC. Matrix models make analysis clearer and provide necessary and sufficient conditions for robust monotonic convergence. They also permit the construction of sufficient frequency domain conditions for robust monotonic convergence on finite time intervals for both causal and non-causal controller dynamics. The results are compared with recent results for robust inverse-model based ILC algorithms and it is seen that the algorithm has the potential to improve robustness to high frequency modelling errors provided that resonances within the plant bandwidth have been suppressed by feedback or series compensation

    Archaeological Investigation of a Spring Lake Lot for Joe\u27s Crab Shack Parking

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    On August 19 and 25, 1997, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio conducted an intensive survey for cultural resources at the proposed location of a parking lot for Joe\u27s Crab Shack Restaurants along Spring Lake, Hays County, Texas. The work was contracted by Southwest Texas State University (SWTSU) and conducted under Texas Antiquities Permit number 1877. Upon completion of the survey and subsurface testing, CAR determined that no cultural resources would be impacted by the planned parking lot construction. CAR therefore recommended that the project sponsor be allowed to proceed as planned with the proposed project and the Texas Historical Commission (THC) has concurred

    Consistency of Markov chain quasi-Monte Carlo on continuous state spaces

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    The random numbers driving Markov chain Monte Carlo (MCMC) simulation are usually modeled as independent U(0,1) random variables. Tribble [Markov chain Monte Carlo algorithms using completely uniformly distributed driving sequences (2007) Stanford Univ.] reports substantial improvements when those random numbers are replaced by carefully balanced inputs from completely uniformly distributed sequences. The previous theoretical justification for using anything other than i.i.d. U(0,1) points shows consistency for estimated means, but only applies for discrete stationary distributions. We extend those results to some MCMC algorithms for continuous stationary distributions. The main motivation is the search for quasi-Monte Carlo versions of MCMC. As a side benefit, the results also establish consistency for the usual method of using pseudo-random numbers in place of random ones.Comment: Published in at http://dx.doi.org/10.1214/10-AOS831 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org
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