Comparative modeling Research Papers - Academia.edu (original) (raw)

Today's households face a huge variety of electricity consuming devices on the one hand, and increasing electricity prices and increased awareness for environmental sustainability on the other hand. Fluctuating electricity tariffs... more

Today's households face a huge variety of electricity consuming devices on the one hand, and increasing electricity prices and increased awareness for environmental sustainability on the other hand. Fluctuating electricity tariffs currently evaluated by electricity suppliers have the potential to make it even more complex for the electricity consumer to keep costs low. We want to help the consumer to manage this complexity and increase her or his awareness for the electricity consumption of the household's devices. Therefore, we have developed a tool which allows to model and simulate the set of electricity consuming devices, their loads, and electricity tariffs. It is possible to create schedules for the usage of devices, calculate the resulting load curve and automatically optimize the schedule based on fluctuating power tariffs while paying attention to customer definable constraints. Furthermore, the tool allows to compare modeled and metered load curves, which is especi...

Geoscience Australia, in an open collaboration with the Mathematical Sciences Institute, The Australian National University, is developing a software ap- plication, ANUGA, to model the hydrodynamics of floods, storm surges and tsunamis.... more

Geoscience Australia, in an open collaboration with the Mathematical Sciences Institute, The Australian National University, is developing a software ap- plication, ANUGA, to model the hydrodynamics of floods, storm surges and tsunamis. The free source software implements a finite volume central- upwind Godunov method to solve the non-linear depth-averagedshallowwater waveequations. Inlight of the renewed interest in tsunami forecasting and mitigation,

The PEBBED code was developed at the Idaho National Laboratory for design and analysis of pebble-bed high temperature reactors. The diffusion-depletion-pebble-mixing algorithm of the original PEBBED code was enhanced through coupling with... more

The PEBBED code was developed at the Idaho National Laboratory for design and analysis of pebble-bed high temperature reactors. The diffusion-depletion-pebble-mixing algorithm of the original PEBBED code was enhanced through coupling with the THERMIX-KONVEK code for thermal fluid analysis and by the COMBINE code for online cross section generation. The COMBINE code solves the B-1 or B-3 approximations to the transport equation for neutron slowing down and resonance interactions in a homogeneous medium with simple corrections for shadowing and thermal self-shielding. The number densities of materials within specified regions of the core are averaged and transferred to COMBINE from PEBBED for updating during the burnup iteration. The simple treatment of self-shielding in previous versions of COMBINE led to inaccurate results for cross sections and unsatisfactory core performance calculations. A new version of COMBINE has been developed that treats all levels of heterogeneity using the...

This paper presents" Scythe and Sew", a software environment for analyzing lighting simulation data. It provides a spreadsheet like infrastructure for manipulating high-dimensional simulation results. It allows users to both... more

This paper presents" Scythe and Sew", a software environment for analyzing lighting simulation data. It provides a spreadsheet like infrastructure for manipulating high-dimensional simulation results. It allows users to both import and create lighting simulation data, or patterns, into a workspace for inspection. A composition area allows the user to perform algebraic operations on the patterns to obtain new insight into the data. This framework allows for a range of lighting assessments including comparing model ...

The enzymatic hydrolysis of urea by jack bean urease was investigated at 25 °C over the pH range 4-9. Reaction rate data were found to be well described by a modified Michaelis-Menten equation with a pH-dependent rate coefficient and a... more

The enzymatic hydrolysis of urea by jack bean urease was investigated at 25 °C over the pH range 4-9. Reaction rate data were found to be well described by a modified Michaelis-Menten equation with a pH-dependent rate coefficient and a product inhibition term. The influence of pH on activity was interpreted in terms of perturbation of the en- zyme distribution

Analysis of the pathways by which research outputs come to the attention of potential users, and of factors which influence uptake, requires selection of an appropriate analytical framework and set of indicators. The main factor... more

Analysis of the pathways by which research outputs come to the attention of potential users, and of factors which influence uptake, requires selection of an appropriate analytical framework and set of indicators. The main factor influencing uptake by users, is the relevance to them of the research output itself. Relevance is not inherent in the research output, but a function of specific contextual factors. In addition the features of the research process and the ‘target’ have a bearing on uptake by intermediate users. Six analytical frameworks are briefly presented and compared. Models of the technology development process suggest questions about the nature and efficiency of linkages between the different elements of the process. Models of information processes focus on the fact that information is not simply passed on but is continually being transformed and adapted through communication. Models of the research management process suggest that the main determinant of relevance is the care and collaboration with which research goals are determined and research implementation is monitored and managed. Systems models allow us to move away from unilinear conceptions of technology development, and can deal more effectively with the diversity of information sources and channels available to potential users. This is also true of the multiple source of innovations and ‘farmer first’ models. Each framework has its uses and limitations: for any particular study, it is important to select one that is most suited to the type of research output and the particular issues under consideration. A wide range of socio-economic research methods have been used to explore promotion and uptake issues. Standard sample survey methods have limitations and alternatives are suggested. Publication, face-to-face interaction and electronic communication are the main pathways for promotion to fellow scientists. Long term relationships between collaborating institutions, and stability in research team composition, are factors in effective promotion at this level. Access to scientific publications in developing country research institutions is seen as a major constraint. Much is already known about the effectiveness of extension and communication methods among end users. There is undoubtedly a lot of untapped potential in the emerging communication technologies for low cost, effective access to agricultural information. The paper ends by suggesting a number of areas for future research on promotion and uptake.

This report covers the important topic of stochastic volatility modelling with an emphasis on linear state models. The approach taken focuses on comparing models based on their ability to flt the data and their forecasting performance. To... more

This report covers the important topic of stochastic volatility modelling with an emphasis on linear state models. The approach taken focuses on comparing models based on their ability to flt the data and their forecasting performance. To this end several parsimonious stochastic volatility models are estimated using realised volatility, a volatility proxy from high frequency stock price data. The

The undrained response of cohesive soils is of paramount importance in geomechanics and it has been modelled extensively for the last 50 years. In comparison, drained behaviour of clays has received only modest attention. Drained and... more

The undrained response of cohesive soils is of paramount importance in geomechanics and it has been modelled extensively for the last 50 years. In comparison, drained behaviour of clays has received only modest attention. Drained and undrained behaviour is significantly affected by past consolidation stress history. This paper evaluates the capabilities of the MIT-S1 effective stress model, described in a companion paper, for predicting the anisotropic stress-strain-strength behaviour of clays. The paper illustrates the selection of model parameters for Lower Cromer Till, using data from standard types of laboratory tests. Comparison of model simulations with measured response for Lower Cromer Till and Boston Blue Clay illustrate model capabilities. The work focuses initially on comparisons of model predictions with measurements from undrained triaxial and plane strain tests on initially K0-consolidated specimens. Comparisons with measured data from undrained shear tests performed in different modes of shearing for LCT and BBC show that the model: (a) gives excellent predictions of maximum shear stress conditions and accurately describes the non-linear shear stress-strain behaviour; (b) accurately describes the anisotropic shear stress-strain-strength conditions for different consolidation stress histories; and (c) gives realistic description of mobilized friction angles, especially at large OCR's. The paper then focuses on the effects of consolidation stress history for isotropically consolidated specimens of resedimented Lower Cromer Till and Boston Blue Clay. Finally, the paper compares model predictions for drained shear tests on K0 and isotropically consolidated specimens with overconsolidation ratios, OCR10, used to evaluate particular aspects of the critical state framework of soil behaviour. Overall, the model gives excellent predictions of the effect of initial anisotropy and overconsolidation stress history on the shear stress-strain and volumetric behaviour of clays.

Forecasting, using historic time-series data, has become an important tool for fisheries management. ARIMA modeling, Modeling for Optimal Forecasting techniques and Decision Support Systems based on fuzzy mathematics may be used to... more

Forecasting, using historic time-series data, has become an important tool for fisheries management. ARIMA modeling, Modeling for Optimal Forecasting techniques and Decision Support Systems based on fuzzy mathematics may be used to predict the general trend of a given fish landings time-series with increased reliability and accuracy. The present paper applies these three modeling methods to forecast anchovy fish catches landed in a given port (Thessaloniki, Greece) during 1979–2000 and hake and bonito total fish catches during 1982–2000. The paper attempts to assess the model's accuracy by comparing model results to the actual monthly fish catches of the year 2000. According to the measures of forecasting accuracy established, the best forecasting performance for anchovy was shown by the DSS model (MAPE = 28.06%, RMSE = 76.56, U-statistic = 0.67 and R2 = 0.69). The optimal forecasting technique of genetic modeling improved significantly the forecasting values obtained by the selected ARIMA model. Similarly, the DSS model showed a noteworthy forecasting efficiency for the prediction of hake landings, during the year 2000 (MAPE = 2.88%, RMSE = 13.75, U-statistic = 0.19 and R2 = 0.98), as compared to the other two modeling techniques. Optimal forecasting produced by combined modeling scored better than application of the simple ARIMA model. Overall, DSS results showed that the Fuzzy Expected Intervals methodology could be used as a very reliable tool for short-term predictions of fishery landings.

Quantitative scenarios are coming of age as a tool for evaluating the impact of future socioeconomic development pathways on biodiversity and ecosystem services. We analyze global terrestrial, freshwater, and marine biodiversity scenarios... more

Quantitative scenarios are coming of age as a tool for evaluating the impact of future socioeconomic development pathways on biodiversity and ecosystem services. We analyze global terrestrial, freshwater, and marine biodiversity scenarios using a range of measures including extinctions, changes in species abundance, habitat loss, and distribution shifts, as well as comparing model projections to observations. Scenarios consistently indicate that biodiversity will continue to decline over the 21st century. However, the range of projected changes is much broader than most studies suggest, partly because there are major opportunities to intervene through better policies, but also because of large uncertainties in projections.