[1] The electric fields associated with streamer discharges in transient luminous events (TLEs) have been recentlymeasured by considering the ratios of spatially integrated radiation intensities of band systems with different energy excitation thresholds. Following recent work by Naidis (2009) we demonstrate that due to strong spatial variations of the electron density and electric field in str...

A large-scale psychophysical experiment was performed examining the effects of various simultaneous variations of image parameters on perceived image sharpness. The goal of this experiment was to unlock some of the rules of image sharpness perception. A paired comparison paradigm was used to compare images of different resolution, contrast, noise, and sharpening. In total, 50 people performed o...

The choice of resolution for a simulation model at a given scale is a trade-off between the level of accuracy offered by the model and the computational cost of its execution. The understanding of this trade-off requires insight in how model resolution and system scale influence accuracy and computational cost. This paper examines performance and accuracy measurements obtained from models of a ...

As biomedical images and volumes are being collected at an increasing speed, there is a growing demand for efficient means to organize spatial information for comparative analysis. In many scenarios, such as determining gene expression patterns by in situ hybridization, the images are collected from multiple subjects over a common anatomical region, such as the brain. A fundamental challenge in...

Computer applications to storm runoff prediction have revolutionized the watershed modeling techniques. In general, a watershed is modeled as a system with inputs and outputs (Chow 1964). A system can be lumped or distributed, depending upon the spatial and temporal characteristics of the design variables used in the model. A lumped parameter ignores the variability in space. On the other hand,...

Parameter estimation of the spatial auto-regression model (SAR) is important because we can model the spatial dependency, i.e., spatial autocorrelation present in the geo-spatial data. SAR is a popular data mining technique used in many geo-spatial application domains such as regional economics, ecology, environmental management, public safety, public health, transportation, and business. Howev...

the complexity of urban systems in our recent world, make it difficult to evaluation and explanation of their changes with traditional and customarily methods. in the past, remote sensing has shown an ability to detect and describe urban growth patterns at different spatial scales. with new remote sensing devices (e.g. ikonos), with innovative image processing techniques and with further develo...

A wide array of spatial units has been explored in current regional safety analysis. Since traffic crashes exhibit extreme spatiotemporal heterogeneity which has rarely been a consideration in partitioning these zoning systems, research based on these areal units may be subjected to the modifiable areal unit problem (MAUP). This study attempted to conduct a sensitivity analysis to quantitativel...

The paper surveys the current state of knowledge of techniques for representing, manipulating and analysing dimensioning and tolerancing data in computer-aided design and manufacturing. The use of solid models and variational geometry, and its implications for the successful integration of CAD and CAM, are discussed. The topics explored so far can be grouped into four categories: (a) the repres...