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Search Results: 1 - 10 of 10130 matches for " Frank Keenan "
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Investigating the Suitability of Agile Methods for Requirements Development of Home Care Systems  [PDF]
Sandra Kelly, Frank Keenan
Journal of Software Engineering and Applications (JSEA) , 2010, DOI: 10.4236/jsea.2010.39104
Abstract: The ageing population in developed countries brings many benefits but also many challenges, particularly in terms of the development of appropriate technology to support their ability to remain in their own home environment. One particular challenge reported for such Home Care Systems (HCS) is the identification of an appropriate requirements development technique for dealing with the typical diverse stakeholders involved. Agile Methods (AMs) recognize this challenge and propose techniques that could be useful. This paper examines the desirable characteristics identified for requirements development in HCS and investigates the extent to which agile practices conform to these. It also sets out future work to improve the situation for the non compliant points found.
Adaptation of Forests and Forest Management to Climate Change: An Editorial
Rodney J. Keenan
Forests , 2012, DOI: 10.3390/f3010075
Abstract: Climate change presents potential risks to forests and challenges for forest managers. Adaptation to climate change involves monitoring and anticipating change and undertaking actions to avoid the negative consequences and take advantage of potential benefits of those changes. Forest managers are accustomed to considering the long-term implications of their decisions. However, many are now responding to much shorter term economic or political imperatives. Climate change potentially increases the consequences of many existing challenges associated with environmental, social or economic change. Some current management measures may continue to be suitable in responding to increasing pressures under climate change, while for other situations new measures will be required. This special issue presents papers from Africa, Europe, and North America that provide examples of the type of analysis being implemented to support forest management in a changing climate. The implications in the context of uncertainty in climate projections and ecosystem responses are discussed.
Calibration of a radiocarbon age
D. J. Keenan
Nonlinear Processes in Geophysics (NPG) , 2012,
Abstract: The calibration of a radiocarbon age to a calendar date is reviewed. It is shown that the commonly-used programs for calibration sometimes give results that are significantly in error.
Why Purchase When You Can Repurpose? Using Crosswalks to Enhance User Access
Teressa M. Keenan
Code4Lib Journal , 2010,
Abstract: The Mansfield Library subscribes to the Readex database U.S. Congressional Serial Set, 1817-1994 (full-text historic reports of Congress and federal agencies). Given the option of purchasing MARC records for all 262,000 publications in the Serial Set or making use of free access to simple Dublin Core records provided by Readex, the library opted to repurpose the free metadata. The process that the Mansfield Library used to obtain the Dublin Core records is described, including the procedures for crosswalking the metadata to MARC and batch loading the bibliographic records complete with holdings information to the local catalog. This report shows that we successfully achieved our goals of dramatically increasing access to Serial Set material by exposing metadata in the local catalog and discusses the challenges we faced along the way. We hope that others tasked with the manipulation of metadata will be able to use what we learned from this project.
Implications of introducing problem-based learning in a traditionally taught course
Christopher Benjamin,Christine Keenan
Engineering Education , 2006,
Abstract: Problem Based Learning (PBL) is a learningand teaching strategy which endeavours topromote active learning by giving controlof the process to the learner. This involvesusing open-ended and unstructuredproblems to trigger learning. The studentshave to analyse the problems, decide whatthey need to know and, having gained theknowledge, develop appropriate solutions.Group work is an integral part of thestrategy, with the sharing and evaluationof learning forming an essential elementin the development of solutions. As thestudents are given control over the detailedcurriculum and are required to evaluateand apply their learning, a greater senseof ownership is engendered than wouldbe by the more traditional educationprocess. This, coupled with the excitementof exploration inherent in PBL, createsa noticeable ‘buzz’ among the learners.However, a number of difficulties arisewhen implementing PBL, especially whenattempting to integrate it into a course ofstudy delivered largely using traditionalteaching methods. Some of thesedifficulties are inherent in the PBL processwhile others arise from the juxtapositionof the two strategies. This paper detailsthe introduction of PBL to one unit of anotherwise traditionally taught programmeand discusses some of the implications ofthis.
Confidence Intervals for Population Allele Frequencies: The General Case of Sampling from a Finite Diploid Population of Any Size
Tak Fung, Kevin Keenan
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085925
Abstract: The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (%), a sample size of is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive % confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint % confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a % confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.
Energy levels, radiative rates, and lifetimes for transitions in W XL
KM Aggarwal,FP Keenan
Physics , 2014, DOI: 10.1016/j.adt.2014.02.006
Abstract: Energy levels and radiative rates are reported for transitions in Br-like W XL, calculated with the general-purpose relativistic atomic structure package ({\sc grasp}). Configuration interaction (CI) has been included among 46 configurations (generating 4215 levels) over a wide energy range up to 213 Ryd. However, for conciseness results are only listed for the lowest 360 levels (with energies up to $\sim$ 43 Ryd), which mainly belong to the 4s$^2$4p$^5$, 4s$^2$4p$^4$4d, 4s$^2$4p$^4$4f, 4s4p$^6$, 4p$^6$4d, 4s4p$^5$4d, 4s$^2$4p$^3$4d$^2$, and 4s$^2$4p$^3$4d4f configurations, and provided for four types of transitions, i.e. E1, E2, M1, and M2. Comparisons are made with existing (but limited) results. However, to fully assess the accuracy of our data, analogous calculations have been performed with the flexible atomic code ({\sc fac}), including even a larger CI than in {\sc grasp}. Our energy levels are estimated to be accurate to better than 0.02 Ryd, whereas results for radiative rates (and lifetimes) should be accurate to better than $20\%$ for a majority of the strong transitions.
Energy levels, radiative rates and electron impact excitation rates for transitions in Si II
KM Aggarwal,FP Keenan
Physics , 2014, DOI: 10.1093/mnras/stu883
Abstract: Energies for the lowest 56 levels, belonging to the 3s$^2$3p, 3s3p$^2$, 3p$^3$, 3s$^2$3d, 3s3p3d, 3s$^2$4$\ell$ and 3s$^2$5$\ell$ configurations of Si II, are calculated using the {\sc grasp} (General-purpose Relativistic Atomic Structure Package) code. Analogous calculations have also been performed (for up to 175 levels) using the Flexible Atomic Code ({\sc fac}). Furthermore, radiative rates are calculated for all E1, E2, M1 and M2 transitions. Extensive comparisons are made with available theoretical and experimental energy levels, and the accuracy of the present results is assessed to be better than 0.1 Ryd. Similarly, the accuracy for radiative rates (and subsequently lifetimes) is estimated to be better than 20% for most of the (strong) transitions. Electron impact excitation collision strengths are also calculated, with the Dirac Atomic R-matrix Code ({\sc darc}), over a wide energy range up to 13 Ryd. Finally, to determine effective collision strengths, resonances are resolved in a fine energy mesh in the thresholds region. These collision strengths are averaged over a Maxwellian velocity distribution and results listed over a wide range of temperatures, up to 10$^{5.5}$ K. Our data are compared with earlier $R$-matrix calculations and differences noted, up to a factor of two, for several transitions. Although scope remains for improvement, the accuracy for our results of collision strengths and effective collision strengths is assessed to be about 20% for a majority of transitions.
Energy levels, radiative rates and electron impact excitation rates for transitions in Be-like Ti XIX
Km Aggarwal,Fp Keenan
Physics , 2012, DOI: 10.1088/0031-8949/85/02/025305
Abstract: We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in Be-like Ti XIX. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted for calculating energy levels and radiative rates. For determining the collision strengths and subsequently the excitation rates, the Dirac Atomic R-matrix Code (DARC) is used. Oscillator strengths, radiative rates and line strengths are reported for all E1, E2, M1 and M2 transitions among the lowest 98 levels of the n <= 4 configurations. Additionally, theoretical lifetimes are listed for all 98 levels. Collision strengths are averaged over a Maxwellian velocity distribution and the effective collision strengths obtained listed over a wide temperature range up to 10**7.7 K. Comparisons are made with similar data obtained from the Flexible Atomic Code (FAC) to highlight the importance of resonances, included in calculations with DARC, in the determination of effective collision strengths. Discrepancies between the collision strengths from DARC and FAC, particularly for forbidden transitions, are also discussed.
Assessment of atomic data: problems and solutions
Km Aggarwal,Fp Keenan
Physics , 2013,
Abstract: For the reliable analysis and modelling of astrophysical, laser-produced and fusion plasmas, atomic data are required for a number of parameters, including energy levels, radiative rates and electron impact excitation rates. Such data are desired for a range of elements (H to W) and their many ions. However, measurements of atomic data, mainly for radiative and excitation rates, are not feasible for many species and therefore calculations are needed. For some ions (such as of C, Fe and Kr) there are a variety of calculations available in the literature, but often they significantly differ from one another. Therefore, there is a great demand from the user community to have data `assessed' for accuracy so that they can be confidently applied to the modelling of plasmas. In this paper we highlight the difficulties in assessing atomic data and offer some solutions for improving the accuracy of calculated results.
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