185 research outputs found

    An analytical model for bore-driven run-up

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    We use a hodograph transformation and a boundary integral method to derive a new analytical solution to the shallow-water equations describing bore-generated run-up on a plane beach. This analytical solution differs from the classical Shen-Meyer runup solution in giving significantly deeper and less asymmetric swash flows, and also by predicting the inception of a secondary bore in both the backwash and the uprush in long surf. We suggest that this solution provides a significantly improved model for flows including swash events and the run-up following breaking tsunamis

    Generation of Formal Model Metrics for MOF based Domain Specific Languages

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    The assessment of quality in a software development process is vital for the quality of the final system. A number of approaches exist, which can be used to determine such quality properties. In a model-driven development process models are the primary artifacts. Novel technologies are needed in order to assess the quality of those artifacts. Often, the Object Constraint Language is used to formulate model metrics and to compute them automatically afterwards. This paper describes an approach for the generation of model metrics expressed as OCL statements based on a set of generic rules. These rules can be applied on any domain specific modeling languages for creating a basic set of metrics which can be tailored for the specific needs of a development process. The paper also briefly describes a prototype of a tool for the generation, computation, and management of these model metrics by using the Software Metrics Meta-model - SMM

    Generation of Formal Model Metrics for MOF based Domain Specific Languages

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    The assessment of quality in a software development process is vital for the quality of the final system. A number of approaches exist, which can be used to determine such quality properties. In a model-driven development process models are the primary artifacts. Novel technologies are needed in order to assess the quality of those artifacts. Often, the Object Constraint Language is used to formulate model metrics and to compute them automatically afterwards. This paper describes an approach for the generation of model metrics expressed as OCL statements based on a set of generic rules. These rules can be applied on any domain specific modeling languages for creating a basic set of metrics which can be tailored for the specific needs of a development process. The paper also briefly describes a prototype of a tool for the generation, computation, and management of these model metrics by using the Software Metrics Meta-model - SMM

    Optimal storage of a single photon by a single intra-cavity atom

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    We theoretically analyse the efficiency of a quantum memory for single photons. The photons propagate along a transmission line and impinge on one of the mirrors of a high-finesse cavity. The quantum memory is constituted by a single atom within the optical resonator. Photon storage is realised by the controlled transfer of the photonic excitation into a metastable state of the atom and occurs via a Raman transition with a suitably tailored laser pulse, which drives the atom. Our study is supported by numerical simulations, in which we include the modes of the transmission line and we use the experimental parameters of existing experimental setups. It reproduces the results derived using input-output theory in the corresponding regime and can be extended to compute dynamics where the input-output formalism cannot be straightforwardly applied. Our analysis determines the maximal storage efficiency, namely, the maximal probability to store the photon in a stable atomic excitation, in the presence of spontaneous decay and cavity parasitic losses. It further delivers the form of the laser pulse that achieves the maximal efficiency by partially compensating parasitic losses. We numerically assess the conditions under which storage based on adiabatic dynamics is preferable to non-adiabatic pulses. Moreover, we systematically determine the shortest photon pulse that can be efficiently stored as a function of the system parameters.Comment: 13 pages, 8 figure

    Evaluation of the QVT Merge Language Proposal

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    -STF90 A05045This report has identified 29 weighted evaluation criteria representing desired properties of a model to model transformation language. These criteria have been used to evaluate the current QVT Merge specification. We have so far only been able to evaluate 21 of these criteria, mainly due to missing tool support. Some of the criteria are considered absolute in the sense that missing to fulfil such a criterion is considered a failure. The 21 evaluated criteria give a score of 59 out of a maximum possible score of 68 (language-based + example-based testing). We have also compared the QVT-Merge submission with the QVT-Compuware/Sun submission and at the time being the QVT-Merge seems to be the preferred one due to more support on the absolute criteria and better easy-to-use score. Eight transformation examples for solving six different transformation tasks have given a lot of insight on the ease of use criteria for both simple and complex transformations. When defining transformations using QVT Merge we believe that a lot of effort may be required in order to define the source and target  metamodels. The evaluation in this report could be improved by using the reference examples with alternative approaches published in the literature. An available QVT-Merge tool is necessary in order to provide evaluations of all the suggested criteria. In order to further investigate the usability of the graphical notation, we need to define more of the transformation examples graphically. Only one of the examples has been specified graphically in this version. The current evaluation has been done by a single evaluator who has only reviewed the transformation code that was written by somebody else. The evaluation will be further improved by incorporating input from other evaluators as well as evaluation from those who wrote the transformation code. Oppdragsgiver: EU Commissio

    Prospectus, September 14, 1977

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    TWO VIE FOR VEEP POST: STUDENT GOVERNMENT ELECTIONS TODAY; Elections scheduled today and tomorrow; District 505 entitled to minimum credit grants; Activities postponed; Unopposed; Shiloh\u27s and Sonshine Circle to perform; Survival of democratic society topic at forum; Vets must go by book; \u27Self Defense\u27 is under attack; Youngest brew master is nun; Warners, women battle over \u27Jump On It\u27; Male prostitute makes history; News From \u27Her Say\u27: Ten women earn wings; UAW asks Congress for maternity benefits \u27as soon as possible\u27; Career Awareness Course for women Wednesday eve.; Instructors earn high grades from PC students; Back orders on home insulation cause woes; Blowing of the shofar means Rosh Hashanah, start of 5,738 New Year; Springfield news: senior citizens, equal language; The gas man cometh...; Holograph exhibit at PC tomorrow; Letting out some Slack...: Answers for queries on PC; Chicago painter displays at KCPA; Prospectus Pigskin Preview: Cobra Grid Schedule, Parkland Roster, Fight on Cobras; Alaskan wilderness is summer home to Basler; Parkland Learning Laboratory: Early help available to students; Stu-Go explores check cashing for PC people; PC music groups have many openings; Jumers: German touch; \u27Elite\u27 women to get public house; Home care topic to be presented; Classifieds; X-country opens Saturday; Spikettes look good; Sports shorts; Bio instructor Cox wins Fast Freddy; Intramural sign up closing; The continuing battle for Number 1; Parkland to host nationalshttps://spark.parkland.edu/prospectus_1977/1013/thumbnail.jp

    A Novel Task for the Investigation of Action Acquisition

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    We present a behavioural task designed for the investigation of how novel instrumental actions are discovered and learnt. The task consists of free movement with a manipulandum, during which the full range of possible movements can be explored by the participant and recorded. A subset of these movements, the ‘target’, is set to trigger a reinforcing signal. The task is to discover what movements of the manipulandum evoke the reinforcement signal. Targets can be defined in spatial, temporal, or kinematic terms, can be a combination of these aspects, or can represent the concatenation of actions into a larger gesture. The task allows the study of how the specific elements of behaviour which cause the reinforcing signal are identified, refined and stored by the participant. The task provides a paradigm where the exploratory motive drives learning and as such we view it as in the tradition of Thorndike [1]. Most importantly it allows for repeated measures, since when a novel action is acquired the criterion for triggering reinforcement can be changed requiring a new action to be discovered. Here, we present data using both humans and rats as subjects, showing that our task is easily scalable in difficulty, adaptable across species, and produces a rich set of behavioural measures offering new and valuable insight into the action learning process

    The Generation Challenge Programme Platform: Semantic Standards and Workbench for Crop Science

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    The Generation Challenge programme (GCP) is a global crop research consortium directed toward crop improvement through the application of comparative biology and genetic resources characterization to plant breeding. A key consortium research activity is the development of a GCP crop bioinformatics platform to support GCP research. This platform includes the following: (i) shared, public platform-independent domain models, ontology, and data formats to enable interoperability of data and analysis flows within the platform; (ii) web service and registry technologies to identify, share, and integrate information across diverse, globally dispersed data sources, as well as to access high-performance computational (HPC) facilities for computationally intensive, high-throughput analyses of project data; (iii) platform-specific middleware reference implementations of the domain model integrating a suite of public (largely open-access/-source) databases and software tools into a workbench to facilitate biodiversity analysis, comparative analysis of crop genomic data, and plant breeding decision making

    Expression profile of genes regulated by activity of the Na-H exchanger NHE1

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    BACKGROUND: In mammalian cells changes in intracellular pH (pH(i)), which are predominantly controlled by activity of plasma membrane ion exchangers, regulate a diverse range of normal and pathological cellular processes. How changes in pH(i )affect distinct cellular processes has primarily been determined by evaluating protein activities and we know little about how pH(i )regulates gene expression. RESULTS: A global profile of genes regulated in mammalian fibroblasts by decreased pH(i )induced by impaired activity of the plasma membrane Na-H exchanger NHE1 was characterized by using cDNA microarrays. Analysis of selected genes by quantitative RT-PCR, TaqMan, and immunoblot analyses confirmed results obtained from cDNA arrays. Consistent with established roles of pH(i )and NHE1 activity in cell proliferation and oncogenic transformation, grouping regulated genes into functional categories and biological pathways indicated a predominant number of genes with altered expression were associated with growth factor signaling, oncogenesis, and cell cycle progression. CONCLUSION: A comprehensive analysis of genes selectively regulated by pH(i )provides insight on candidate targets that might mediate established effects of pH(i )on a number of normal and pathological cell functions

    Differential Modulation of Angiogenesis by Erythropoiesis-Stimulating Agents in a Mouse Model of Ischaemic Retinopathy

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    BACKGROUND: Erythropoiesis stimulating agents (ESAs) are widely used to treat anaemia but concerns exist about their potential to promote pathological angiogenesis in some clinical scenarios. In the current study we have assessed the angiogenic potential of three ESAs; epoetin delta, darbepoetin alfa and epoetin beta using in vitro and in vivo models. METHODOLOGY/PRINCIPAL FINDINGS: The epoetins induced angiogenesis in human microvascular endothelial cells at high doses, although darbepoetin alfa was pro-angiogenic at low-doses (1-20 IU/ml). ESA-induced angiogenesis was VEGF-mediated. In a mouse model of ischaemia-induced retinopathy, all ESAs induced generation of reticulocytes but only epoetin beta exacerbated pathological (pre-retinal) neovascularisation in comparison to controls (p<0.05). Only epoetin delta induced a significant revascularisation response which enhanced normality of the vasculature (p<0.05). This was associated with mobilisation of haematopoietic stem cells and their localisation to the retinal vasculature. Darbepoetin alfa also increased the number of active microglia in the ischaemic retina relative to other ESAs (p<0.05). Darbepoetin alfa induced retinal TNFalpha and VEGF mRNA expression which were up to 4 fold higher than with epoetin delta (p<0.001). CONCLUSIONS: This study has implications for treatment of patients as there are clear differences in the angiogenic potential of the different ESAs
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