4,578 research outputs found

    An Investigation of the Utility of Microblogging in a Virtual Organisation

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    Virtualisation is one possible business strategy of an organisation. The nature of virtual organisations is that individuals or teams are distributed over different work sites. This leads to barriers in communication,coordination and collaboration between these entities due to dispersed expertise, time zones, languages, cultures, etc. To address these issues, virtual organisations have invested in ICT for supporting collaboration between cross-site colleagues. One very new collaborative technology is microblogging. Microblogging supports asynchronous communication between multiple persons. Microblogging is based upon transmission of short messages that can be sent from Web-based microblogging systems, instant messaging tools, email or mobile phones. Microblogging has some relevant features like simplicity, immediacy, accessibility and presence. This paper describes our investigation of the utility of microblogging, particularly the Twitter tool, for collaboration support in a virtual organisation. Since microblogging is very new and was introduced only recently, no work has been done on this exact topic. The investigation involved conducting an online survey to collect participants’ opinions about the utility of Twitter in the workplace after using Twitter over a three-week period. The study yielded quantitative and qualitative results regarding participants’ experience of Twitter. It was found that microblogging could be adapted to virtual organisations quickly due to ease of use in terms of taking less time and effort for creating microblogs. Twitter could be used in virtual organisations for collaboration support because it is believed that the use of Twitter could somewhat improve communication between cross-site co-workers. However, to be well accepted by virtual organisations, Twitter needs improvement and addition to its existing functionality

    Effects of cobalt in nickel-base superalloys

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    The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys

    Charmed Baryon Weak Decays with SU(3) Flavor Symmetry

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    We study the semileptonic and non-leptonic charmed baryon decays with SU(3)SU(3) flavor symmetry, where the charmed baryons can be Bc=(Ξc0,Ξc+,Λc+){\bf B}_{c}=(\Xi_c^0,\Xi_c^+,\Lambda_c^+), Bc=(Σc(++,+,0),Ξc(+,0),Ωc0){\bf B}'_{c}=(\Sigma_c^{(++,+,0)},\Xi_{c}^{\prime(+,0)},\Omega_c^0), Bcc=(Ξcc++,Ξcc+,Ωcc+){\bf B}_{cc}=(\Xi_{cc}^{++},\Xi_{cc}^+,\Omega_{cc}^+), or Bccc=Ωccc++{\bf B}_{ccc}=\Omega^{++}_{ccc}. With Bn(){\bf B}_n^{(\prime)} denoted as the baryon octet (decuplet), we find that the BcBn+ν{\bf B}_{c}\to {\bf B}'_n\ell^+\nu_\ell decays are forbidden, while the Ωc0Ω+ν\Omega_c^0\to \Omega^-\ell^+\nu_\ell, Ωcc+Ωc0+ν\Omega_{cc}^+\to\Omega_c^0\ell^+\nu_\ell, and Ωccc++Ωcc++ν\Omega_{ccc}^{++}\to \Omega_{cc}^+\ell^+\nu_\ell decays are the only existing Cabibbo-allowed modes for BcBn+ν{\bf B}'_{c}\to {\bf B}'_n\ell^+\nu_\ell, BccBc+ν{\bf B}_{cc}\to {\bf B}'_c\ell^+\nu_\ell, and BcccBcc()+ν{\bf B}_{ccc}\to {\bf B}_{cc}^{(\prime)}\ell^+\nu_\ell, respectively. We predict the rarely studied BcBn()M{\bf B}_{c}\to {\bf B}_n^{(\prime)}M decays, such as B(Ξc0Λ0Kˉ0,Ξc+Ξ0π+)=(8.3±0.9,8.0±4.1)×103{\cal B}(\Xi_c^0\to\Lambda^0\bar K^0,\,\Xi_c^+\to\Xi^0\pi^+)=(8.3\pm 0.9,8.0\pm 4.1)\times 10^{-3} and B(Λc+Δ++π,Ξc0ΩK+)=(5.5±1.3,4.8±0.5)×103{\cal B}(\Lambda_c^+\to \Delta^{++}\pi^-,\,\Xi_c^0\to\Omega^- K^+)=(5.5\pm 1.3,4.8\pm 0.5)\times 10^{-3}. For the observation, the doubly and triply charmed baryon decays of Ωcc+Ξc+Kˉ0\Omega_{cc}^{+}\to \Xi_c^+\bar K^0, Ξcc++(Ξc+π+\Xi_{cc}^{++}\to (\Xi_c^+\pi^+, Σc++Kˉ0)\Sigma_c^{++}\bar K^0), and Ωccc++(Ξcc++Kˉ0,Ωcc+π+,Ξc+D+)\Omega_{ccc}^{++}\to (\Xi_{cc}^{++}\bar K^0,\Omega_{cc}^+\pi^+,\Xi_c^+ D^+) are the favored Cabibbo-allowed decays, which are accessible to the BESIII and LHCb experiments.Comment: 29 pages, no figure, a typo in the table correcte

    Exercise Interventions in Children with Cancer: A Review

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    The purpose of this review is to summarize literature that describes the impact of exercise on health and physical function among children during and after treatment for cancer. Relevant studies were identified by entering the following search terms into Pubmed: aerobic training; resistance training; stretching; pediatric; children; AND cancer. Reference lists in retrieved manuscripts were also reviewed to identify additional trials. We include fifteen intervention trials published between 1993 and 2011 that included children younger than age 21 years with cancer diagnoses. Nine included children with an acute lymphoblastic leukemia (ALL) diagnosis, and six children with mixed cancer diagnoses. Generally, interventions tested were either in-hospital supervised exercise training or home based programs designed to promote physical activity. Early evidence from small studies indicates that the effects of exercise include increased cardiopulmonary fitness, improved muscle strength and flexibility, reduced fatigue and improved physical function. Generalizations to the entire childhood cancer and childhood cancer survivor populations are difficult as most of the work has been done in children during treatment for and among survivors of ALL. Additional randomized studies are needed to confirm these benefits in larger populations of children with ALL, and in populations with cancer diagnoses other than ALL

    Subsolidus Phase Relations in Part of the System Si,Al,Y/N,O

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65882/1/j.1151-2916.1979.tb12762.x.pd

    Two-Stage Likelihood Ratio and Union–Intersection Tests for One-Sided Alternatives Multivariate Mean with Nuisance Dispersion Matrix

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    For a multinormal distribution with an unknown dispersion matrix, union-intersection (UI) tests for the mean against one-sided alternatives are considered. The null distribution of the UI test statistic is derived and its power monotonicity properties are studied. A Stain-type two-stage procedure is proposed to eliminate some of the inherent drawbacks of such tests. Some comparisons are also made with some recently proposed alternative conditional likelihood ratio tests
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