5,258 research outputs found

    Developing and applying an integrated modular design methodology within a SME

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    Modularity within a product can bring advantages to the design process by facilitating enhanced design reuse, reduced lead times, decreased cost and higher levels of quality. While the benefits of modularity are becoming increasingly better known, at present it is usually left to the designers themselves to introduce modularity into products. Studies into modularity have shown that byimplementing 'formal' methods, further benefits can be made in terms of time, cost, quality and performance. Current approaches that have been proposed for the formal development of modular design methodologies fail to accurately represent knowledge that is inherently produced during design projects and fail to consider design from the different viewpoints of the development process. This work, built on previous work on modularity and design for reuse, aims to develop an integrated design methodology that will optimise the modules created through the design process and allow for modularity to be 'built-in' to product development from the initial stages. The methodology andassociated tools have been developed to provide an easy-to-use approach to modularity that has support for design rationales and company knowledge that aid in effective design decision making. The methodology, named GeMoCURE, provides an integrated total solution to modular design based on reuse of proven physical and knowledge modules. Its incremental nature allows for the optimalstructure to be maintained as the design progresses. A special focus has been on the application of this approach for Small to Medium Enterprises (SMEs), which are typically challenged by a lack of design human resources and expertise

    Teaching HDFS/MapReduce Systems Concepts to Undergraduates

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    This paper presents the development of a Hadoop MapReduce module that has been taught in a course in distributed computing to upper undergraduate computer science students at Clemson University. The paper describes our teaching experiences and the feedback from the students over several semesters that have helped to shape the course. We provide suggested best practices for lecture materials, the computing platform, and the teaching methods. In addition, the computing platform and teaching methods can be extended to accommodate emerging technologies and modules for related courses

    Teaching HDFS/MapReduce Systems Concepts to Undergraduates

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    This paper presents the development of a Hadoop MapReduce module that has been taught in a course in distributed computing to upper undergraduate computer science students at Clemson University. The paper describes our teaching experiences and the feedback from the students over several semesters that have helped to shape the course. We provide suggested best practices for lecture materials, the computing platform, and the teaching methods. In addition, the computing platform and teaching methods can be extended to accommodate emerging technologies and modules for related courses

    Teaching HDFS/MapReduce Systems Concepts to Undergraduates

    Get PDF
    This paper presents the development of a Hadoop MapReduce module that has been taught in a course in distributed computing to upper undergraduate computer science students at Clemson University. The paper describes our teaching experiences and the feedback from the students over several semesters that have helped to shape the course. We provide suggested best practices for lecture materials, the computing platform, and the teaching methods. In addition, the computing platform and teaching methods can be extended to accommodate emerging technologies and modules for related courses

    Teaching HDFS/MapReduce Systems Concepts to Undergraduates

    Get PDF
    This paper presents the development of a Hadoop MapReduce module that has been taught in a course in distributed computing to upper undergraduate computer science students at Clemson University. The paper describes our teaching experiences and the feedback from the students over several semesters that have helped to shape the course. We provide suggested best practices for lecture materials, the computing platform, and the teaching methods. In addition, the computing platform and teaching methods can be extended to accommodate emerging technologies and modules for related courses

    Mechanical characterization of a customized decellularized scaffold for vascular tissue engineering.

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    Several challenges persist when attempting to utilize decellularized tissue as a scaffold for vascular tissue engineering. Namely: poor cell infiltration/migration, excessive culture times associated with repopulating the scaffolds, and the achievement of a quiescent medial layer. In an attempt to create an optimum vascular scaffold, we customized the properties of decellularized porcine carotid arteries by: (i) creating cavities within the medial layer to allow direct injection of cells, and (ii) controlling the amount of collagen digestion to increase the porosity. Histological examination of our customized scaffold revealed a highly porous tissue structure containing consistent medial cavities running longitudinally through the porous scaffold wall. Mechanical testing of the customized scaffold showed that our minimal localized disruption to the ECM does not have a detrimental effect on the bulk mechanical response of the tissue. The results demonstrate that an increased stiffness and reduced distensibility occurs after decellularization when compared to the native tissue, however post scaffold customization we can revert the scaffold tensile properties back to that of the native tissue. This most noteworthy result occurs in the elastin dominant phase of the tensile response of the scaffold, indicating that no disruption has occurred to the elastin network by our decellularization and customization techniques. Additionally, the bulk seeding potential of the customized scaffold was demonstrated by direct injection of human smooth muscle cells through the medial cavities. The optimum cell dispersion was observed in the highest porosity scaffold, with large cell numbers retained within the medial layer after 24 h static culture. In summary, this study presents a novel customized decellularized vascular scaffold that has the capability of bulk seeding the media, and in tandem to this method, the porosity of the scaffold has been increased without compromising the mechanical integrity

    Dark-ages Reionization & Galaxy Formation Simulation VIII. Suppressed growth of dark matter halos during the Epoch of Reionization

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    We investigate how the hydrostatic suppression of baryonic accretion affects the growth rate of dark matter halos during the Epoch of Reionization. By comparing halo properties in a simplistic hydrodynamic simulation in which gas only cools adiabatically, with its collisionless equivalent, we find that halo growth is slowed as hydrostatic forces prevent gas from collapsing. In our simulations, at the high redshifts relevant for reionization (between 6{\sim}6 and 11{\sim}11), halos that host dwarf galaxies (109M\lesssim 10^{9} \mathrm{M_\odot}) can be reduced by up to a factor of 2 in mass due to the hydrostatic pressure of baryons. Consequently, the inclusion of baryonic effects reduces the amplitude of the low mass tail of the halo mass function by factors of 2 to 4. In addition, we find that the fraction of baryons in dark matter halos hosting dwarf galaxies at high redshift never exceeds 90%{\sim}90\% of the cosmic baryon fraction. When implementing baryonic processes, including cooling, star formation, supernova feedback and reionization, the suppression effects become more significant with further reductions of 30%{\sim}30\% to 60\%. Although convergence tests suggest that the suppression may become weaker in higher resolution simulations, this suppressed growth will be important for semi-analytic models of galaxy formation, in which the halo mass inherited from an underlying N-body simulation directly determines galaxy properties. Based on the adiabatic simulation, we provide tables to account for these effects in N-body simulations, and present a modification of the halo mass function along with explanatory analytic calculations.Comment: 17 pages, 11 figures; Updated to match the published version. Two changes in Figures 1 and 3 in order to 1) correct bin sizes of the 10^8 and 10^8.5 Msol bins for NOSN_NOZCOOL_NoRe (was 0.5, should be 0.25); 2) include stellar mass in baryon fraction (was missed in Fig. 3). Quantitative description of Fig. 3 changed slightly in Section 2.2. All other results and conclusions remain unchange

    Dark-ages reionization and galaxy formation simulation--VII. The sizes of high-redshift galaxies

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    We investigate high-redshift galaxy sizes using a semi-analytic model constructed for the Dark-ages Reionization And Galaxy-formation Observables from Numerical Simulation project. Our fiducial model, including strong feedback from supernovae and photoionization background, accurately reproduces the evolution of the stellar mass function and UV luminosity function. Using this model, we study the size--luminosity relation of galaxies and find that the effective radius scales with UV luminosity as ReL0.25R_\mathrm{e}\propto L^{0.25} at z5z{\sim}5--99. We show that recently discovered very luminous galaxies at z7z{\sim}7 (Bowler et al. 2016) and z11z{\sim}11 (Oesch et al. 2016) lie on our predicted size--luminosity relations. We find that a significant fraction of galaxies at z>8z>8 will not be resolved by JWST, but GMT will have the ability to resolve all galaxies in haloes above the atomic cooling limit. We show that our fiducial model successfully reproduces the redshift evolution of average galaxy sizes at z>5z>5. We also explore galaxy sizes in models without supernova feedback. The no-supernova feedback models produce galaxy sizes that are smaller than observations. We therefore confirm that supernova feedback plays an important role in determining the size--luminosity relation of galaxies and its redshift evolution during reionization.Comment: 10 pages, 4 figures, Accepted for publication in MNRA

    Application of remote sensing to state and regional problems

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    The methods and procedures used, accomplishments, current status, and future plans are discussed for each of the following applications of LANDSAT in Mississippi: (1) land use planning in Lowndes County; (2) strip mine inventory and reclamation; (3) white-tailed deer habitat evaluation; (4) remote sensing data analysis support systems; (5) discrimination of unique forest habitats in potential lignite areas; (6) changes in gravel operations; and (7) determining freshwater wetlands for inventory and monitoring. The documentation of all existing software and the integration of the image analysis and data base software into a single package are now considered very high priority items

    Dark-ages reionization & galaxy formation simulation IV: UV luminosity functions of high-redshift galaxies

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    In this paper we present calculations of the UV luminosity function from the Dark-ages Reionization And Galaxy-formation Observables from Numerical Simulations (DRAGONS) project, which combines N-body, semi-analytic and semi-numerical modelling designed to study galaxy formation during the Epoch of Reionization. Using galaxy formation physics including supernova feedback, the model naturally reproduces the UV LFs for high-redshift star-forming galaxies from z5z{\sim}5 through to z10z{\sim}10. We investigate the luminosity--star formation rate (SFR) relation, finding that variable SFR histories of galaxies result in a scatter around the median relation of 0.10.1--0.30.3 dex depending on UV luminosity. We find close agreement between the model and observationally derived SFR functions. We use our calculated luminosities to investigate the luminosity function below current detection limits, and the ionizing photon budget for reionization. We predict that the slope of the UV LF remains steep below current detection limits and becomes flat at MUV14M_\mathrm{UV}{\gtrsim}{-14}. We find that 4848 (1717) per cent of the total UV flux at z6z{\sim}6 (1010) has been detected above an observational limit of MUV17M_\mathrm{UV}{\sim}{-17}, and that galaxies fainter than MUV17M_\mathrm{UV}{\sim}{-17} are the main source of ionizing photons for reionization. We investigate the luminosity--stellar mass relation, and find a correlation for galaxies with MUV<14M_\mathrm{UV}{<}{-14} that has the form M100.47MUVM_*{\propto}10^{-0.47M_\mathrm{UV}}, in good agreement with observations, but which flattens for fainter galaxies. We determine the luminosity--halo mass relation to be Mvir100.35MUVM_\mathrm{vir}{\propto}10^{-0.35M_\mathrm{UV}}, finding that galaxies with MUV=20M_\mathrm{UV}{=}{-20} reside in host dark matter haloes of 1011.0±0.1M10^{11.0\pm 0.1}\mathrm{M_\odot} at z6z{\sim}6, and that this mass decreases towards high redshift.Comment: 17 pages, 14 figures, Accepted for publication in MNRA
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