We extend the Tauer (2001) and Fare et al. (2004) analyses of aggregation bias in technical efficiency measurement to multiple criteria decision analysis. We show input aggregation conditions consistent with multiple ...
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We extend the Tauer (2001) and Fare et al. (2004) analyses of aggregation bias in technical efficiency measurement to multiple criteria decision analysis. We show input aggregation conditions consistent with multiple criteria evaluation of overall efficiency in conjunction with the variation in aggregation bias.
In single-site validations, site-pixel, synthetic pixel and footprint-integrated methods are commonly used to validate evapotranspiration (ET) retrieval at the pixel scale. To reveal the reliability of these methods, ...
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In single-site validations, site-pixel, synthetic pixel and footprint-integrated methods are commonly used to validate evapotranspiration (ET) retrieval at the pixel scale. To reveal the reliability of these methods, this study analysed the performance of the three methods for ET retrieval validation based on eddy-covariance observations at the Daman site which is numerously used for validation in Heihe Watershed Allied Telemetry Experimental Research (HiWATER). The analysis at different spatial scales in different seasons showed that the validation results of the site-pixel method were more similar that of the footprint-integrated method than the synthetic pixel method. However, the validation results of the site-pixel method showed significant discrepancies from those of the footprint-integrated method, especially in summer at the 480 M scale which is near to the spatial resolution of MODIS with a large difference of more than 125.65 W M-2. This error is due to aggregation and high spatial heterogeneity. The use of synthetic pixel can avoid this error. Normally, the error probably appears when the wind direction is 270 degrees-360 degrees, usually in summer, autumn and winter. In addition, the different aggregation methods had a slight effect on the ET estimation results. This study is helpful in determining the reliability of different single-point validation methods and provides a reliable way to select a validation method for single-site validation of remote sensing retrieval of ET.
This paper presents a framework for a systematic analysis of the impact of data aggregation on a multi-product multi-period network design problem with batch cost. The optimization objective is to design the vehicle d...
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This paper presents a framework for a systematic analysis of the impact of data aggregation on a multi-product multi-period network design problem with batch cost. The optimization objective is to design the vehicle distribution network for an automotive manufacturer. Numerical experiments are conducted with real production data. Given the problem's scale and complex constraints, data aggregation emerges as a natural strategy to help the convergence of resolution methods towards good solutions. We explore three aggregation dimensions: product type, spatial, and temporal, and for each of them, different levels. Addressing multiple aggregation dimensions is a novel approach that has not been extensively explored in current literature, especially within industrial settings. Our aggregation-disaggregation method reveals that data aggregation consistently leads to improved solutions within a constrained computation time, with temporal aggregation demonstrating the most significant reduction in problem size and solution improvement. Lastly, we give some managerial insights considering the industrial context.
Sharing game control (SGC) is a multiplayer context that is considered within games user research. With the popular "Twitch Plays Pokemon", settings of this type have also received broad media attention. In ...
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ISBN:
(纸本)9781450359719
Sharing game control (SGC) is a multiplayer context that is considered within games user research. With the popular "Twitch Plays Pokemon", settings of this type have also received broad media attention. In this paper, we introduce and describe HedgewarsSGC, our modifications to the open-source game Hedgewars to investigate different player roles in this shared game control context: besides considering competing groups who share control over their units via input aggregators, it also provides options for spectators that do not want to give up individual control. Thus, HedgewarsSGC is an approach to investigate SGC in such a scenario and additionally, allows further reasoning about input aggregation.
Recently, gaming live-streams appeared in which the audience interacts without a streamer. These settings sometimes allow the audience to select from a set of input aggregators to mediate how individual contributions ...
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ISBN:
(纸本)9781450348980
Recently, gaming live-streams appeared in which the audience interacts without a streamer. These settings sometimes allow the audience to select from a set of input aggregators to mediate how individual contributions are aggregated. We developed CrowdChess, a system which is optimized for the live-streaming context: multiple viewers play chess together in a single game instance against an AI;they suggest moves and further select one of six aggregators to mediate their contributions. In contrast to existing approaches, CrowdChess allows reasoning about the quality of individual and aggregator contributions, and thus it serves as a test bed for how effectively an audience interacts in such settings. We conducted a study in a live-streaming setup (n=12) and contribute insights on the player perception of audience-driven games and show how aggregators in such a small-scale setting are used, for example, the tendency to use group-based aggregators instead of empowering an individual.
The influence of spatial resolution on the estimation of land surface heat fluxes from remote sensing is poorly understood. In this study, the effects of aggregation from fine (<100 m) to medium (approx. 1 km) scal...
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The influence of spatial resolution on the estimation of land surface heat fluxes from remote sensing is poorly understood. In this study, the effects of aggregation from fine (<100 m) to medium (approx. 1 km) scales are investigated using high resolution Landsat 5 overpasses. A temporal sequence of satellite imagery and needed meteorological data were collected over an agricultural region, capturing distinct variations in crop stage and phenology. Here, we investigate both the impact of aggregating the input forcing and of aggregating the derived latent heat flux. In the input aggregation scenario, the resolution of the Landsat based radiance data was increased incrementally from 120 m to 960 m, with the land surface temperature calculated at each specific resolution. Reflectance based land surface parameters such as vegetation height and leaf area index were first calculated at the native 30 m Landsat resolution and then aggregated to multiple spatial scales. Using these data and associated meteorological forcing, surface heat fluxes were calculated at each distinct resolution using the Surface Energy Balance System (SEBS) model. Results indicate that aggregation of input forcing using a simple averaging method has limited effect on the land surface temperature and available energy, but can reduce evapotranspiration estimates at the image scale by up to 15%, and at the pixel scale by up to 50%. It was determined that the predominant reason for the latent heat flux reduction in SEBS was a decrease in the aerodynamic resistance at coarser resolutions, which originates from a change in the roughness length parameters of the land surface due to the aggregation. In addition, the magnitude of errors in surface heat flux estimation due to input aggregation was observed to be a function of the heterogeneity of the land surface and evaporative elements. In examining the response of flux aggregation, fine resolution (120 m) heat fluxes were aggregated to coarser resolutions
Crop models are indispensable to assess crop production under climate change, and they need evaluation preferably on long-term experiments. The certainty of estimates depends on the detail of input data and selection ...
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