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Publication Search Results

Now showing 1 - 10 of 13
  • (2001) Corkish, Richard; Altermatt, Pietro P.; Heiser, Gernot
    Journal Article
    Three-dimensional numerical simulations of electron-beam-induced current (EBIC) near a vertical silicon grain boundary are demonstrated. They are compared with an analytical model which excludes the effect of carrier generation other than in the bulk base region of a solar cell structure. We demonstrate that in a wide range of solar cell structures recombination in the space charge region (SCR) significantly affects the EBIC results and hence needs to be included in the data evaluation. Apart from these findings, simulations of a realistic silicon solar cell structure (thick emitter, field-dependent mobility, etc.) are demonstrated.

  • (2000) Cotera, Angela; Simpson, John; Erickson, E; Colgan, Sean; Burton, Michael; Allen, David
    Journal Article

  • (2005) Russell, Carol; Lee, Adrian
    Conference Paper
    In this paper we describe an institutionally funded Fellowship running 2001– 2004, which seeded and cultivated new communities of practice in innovative teaching using educational technology. The literature identifies some inherent challenges in such schemes. The Fellowship was able to surface and deal with these through a team-based action research approach. Key features were the buying out of staff time for a semester and the development of discipline-based projects in a supported cross-disciplinary group. The Fellowship has been central to shifting systemic institutional blocks to educational innovation.

  • (2007) Zhu, Liming; Ali Babar, Muhammad; Staples, Mark; Nonaka, Makoto
    Book Chapter
    The possible variability of project delay is useful information to understand and mitigate the project delay risk. However, it is not sufficiently considered in the literature concerning effort estimation and simulation in software product line development. In this paper, we propose a project delay simulation model by introducing a random variable to represent the variability of adaptive rework. The model has been validated through stochastic simulations by comparing generated adaptive rework to an actual change effort distribution, and by sensitivity analysis. The result shows that the proposed model is capable of producing reasonable variability of adaptive rework, and consequently, variability of project delay. Analysis of our model indicates that the strength of dependency has a larger impact than the number of residual defects, for the studied simulation settings. However, high levels of adaptive rework variability did not have great impact on overall project delay.

  • (2007) Theo, J.; Mazaheri, M.; Tabatabaei Balaei, Asghar; Dempster, A.G
    Conference Paper

  • (2005) Su, H; McCabe, Matthew Francis; Wood, E.F.; Su, Z; Prueger, J.
    Journal Article
    he Surface Energy Balance System (SEBS) model was developed to estimate land surface fluxes using remotely sensed data and available meteorology. In this study, a dual assessment of SEBS is performed using two independent, high-quality datasets that are collected during the Soil Moisture-Atmosphere Coupling Experiment (SMACEX). The purpose of this comparison is twofold. First, using high-quality local-scale data, model-predicted surface fluxes can be evaluated against in situ observations to determine the accuracy limit at the field scale using SEBS. To accomplish this, SEBS is forced with meteorological data derived from towers distributed throughout the Walnut Creek catchment. Flux measurements from 10 eddy covariance systems positioned on these towers are used to evaluate SEBS over both corn and soybean surfaces. These data allow for an assessment of modeled fluxes during a period of rapid vegetation growth and varied hydrometeorology. Results indicate that SEBS can predict evapotranspiration with accuracies approaching 10%-15% of that of the in situ measurements, effectively capturing the temporal development of surface flux patterns for both corn and soybean, even when the evaporative fraction ranges between 0.50 and 0.90. Second, utilizing high-resolution remote sensing data and operational meteorology, a catchment-scale examination of model performance is undertaken. To extend the field-based assessment of SEBS, information derived from the Landsat Enhanced Thematic Mapper (ETM) and data from the North American Land Data Assimilation System (NLDAS) were combined to determine regional surface energy fluxes for a clear day during the field experiment. Results from this analysis indicate that prediction accuracy was strongly related to crop type, with corn predictions showing improved estimates compared to those of soybean. Although root-mean-square errors were affected by the limited number of samples and one poorly performing soybean site, differences between the mean values of observations and SEBS Landsat-based predictions at the tower sites were approximately 5%. Overall, results from this analysis indicate much potential toward routine prediction of surface heat fluxes using remote sensing data and operational meteorology. © 2005 American Meteorological Society.

  • (2009) Cox, Shane; Frances, Maude; Croucher, Joanne; Sidhunata, Harry; Leslie, Greg
    Conference Paper
    The Membrane Research Environment (MemRE) is a component research infrastructure project of the Advanced Membrane Technologies for Water Treatment Research Cluster, a research project funded by the CSIRO flagship Water for a Healthy Country. The research cluster, a nationally distributed and multidisciplinary group of researchers including computational and physical chemists, physicists, material scientists, and chemical and mechanical engineers, aims to develop novel membrane materials in order to reduce the energy associated with desalination by 40%. Common hurdles in multidisciplinary research projects include: a lack of consolidation of existing information relevant to the research from all the participating fields; an absence of information infrastructure to promote comparison of results; and the need for a common language to better enable project participants to communicate. MemRE has been designed and implemented as a solution to these hurdles, to provide an integrated research development tool and learning environment.

  • (2010) Cole, Fletcher; Cox, Shane; Frances, Maude
    Conference Paper
    An opportunity to explore the topic of data usages is presented by the collaborative research being undertaken by a federation of applied science research units affiliated with a number of different Australian research organizations (the Cluster). The research aims to investigate how members of the collaboration understand and work with data in their day-to-day practice.

  • (2006) Doran, Michael
    The transplantation of ex vivo expanded mobilized peripheral blood haematopoietic stem cells (PBSC), in place of unmanipulated cells following high dose chemotherapy, reduces the period of cytopenia associated with the therapy’s hemotoxicity. In this thesis the development and optimization of a preclinical prototype hollow fiber bioreactor (HFBR) for the ex vivo expansion of PBSC is described. Mass transport measurements and model of metabolite profiles demonstrate that Cuprophan and Polyflux are suitable membrane material for high-density cell expansion in a HFBR. Materials selected for the HFBR were found to be non-toxic following a 20-day saline extraction. Growth factor (GF) adsorption to the Polyflux membrane makes it unsuitable for expansion of GF dependent cells. However, the GF retention and minimal adsorption characteristics of the Cuprophan membrane are appropriate for this application. Cell-free medium degrades at 37ºC by an oxygen dependent process generating byproducts that inhibit cell growth. This process is relevant to perfusion bioreactors where the bulk of the medium is maintained at 37ºC and is cell-free. Albumin was shown to slow the degradation process but was itself degraded by shear damage inflicted during recirculation. Treating recirculating medium with dialysis against albumin was shown to be a more effective way to mitigate the effects of degradation and lengthen the functional life of albumin over conventional suspension of albumin in the recirculating medium. The preclinical prototype HFBR utilised dialysis against albumin to expand KG-1a cultures from densities as low as 3.5x10^5 cells/ml up to as high as 2x10^8 cells/ml with expansion rates equivalent to T-flask cultures. This process was then applied to PBSC where the targeted 100-fold expansion was achieved. Process optimization was continued using cord blood (CB) CD34+ cells. Growth factor loading sufficient for PBSC expansion in the HFBR was inadequate for CB expansions due to greater than anticipated CB uptake rates. The cell product from the HFBR contained significantly greater yields of CD34+ cells than attained using T-flask cultures. The HFBR platform is suitable for PBSC expansion and appears promising for CB expansion.

  • (2019) Zhang, Weizheng
    Wireless communication has been developed rapidly in recent years with the utilization of multiple-input multiple-output (MIMO) systems. One promising technique to support ultra-high data rate communication is massive MIMO, or large MIMO, where the number of antennas goes to tens or hundreds. Unmanned Aerial Vehicles (UAVs) have the advantages of high mobility and flexibility that can be used as aerial nodes to provide communication to ground users or base stations. In this thesis, the optimization of pilot based channel estimation with limited pilot length is studied for a massive MIMO system. The pilot length is optimized to maximize the system spectral efficiency. Then, the optimal pilot design is discussed under the constraint of finite pilot length. The performance of uplink signal-to-interference-plus-noise ratio (SINR) and the effect of feedback error are also analyzed in time division duplex (TDD) and frequency division duplex (FDD), respectively. Then, a large MIMO system is utilized for UAV communication. In order to provide directional beamforming, the channel estimation in UAV millimeter wave (mmWave) system is studied. A beam training and tracking method is proposed with user mobility. For beam training, a training codebook is designed based on user location distribution. For beam tracking, two tracking methods are proposed based on different types of user mobility to reduce the training overhead. The proposed beam training codebook provides larger average downlink capacity than the conventional codebook. The proposed beam tracking design is also shown to outperform the existing methods. Lastly, a multiple UAV system in mmWave band is considered and studied. Hybrid beamforming is designed for both fully connected antenna array and partially connected subarray structures. Furthermore, a simultaneous beam tracking scheme for multiple UAV users is proposed based on subarray structure, where both UAV mobility and instability effects are taken into consideration. Simulation results show that with the proposed method, the average downlink sum capacity is improved.