Development and Evolution of Neural Networks in an Artificial Chemistry

We present a model of decentralized growth for Artificial Neural Networks (ANNs) inspired by the development and the physiology of real nervous systems. In this model, each individual artificial neuron is an autonomous unit whose behavior is determined only by the genetic information it harbors and local concentrations of substrates modeled by a simple artificial chemistry. Gene expression is manifested as axon and dendrite growth, cell division and differentiation, substrate production and cell stimulation. We demonstrate the model's power with a hand-written genome that leads to the growth of a simple network which performs classical conditioning. To evolve more complex structures, we implemented a platform-independent, asynchronous, distributed Genetic Algorithm (GA) that allows users to participate in evolutionary experiments via the World Wide Web.Comment: 8 pages LaTeX, style file included, 8 embedded postscript figures. To be published in Proc. of 3rd German Workshop on Artificial Life (GWAL

Democracy in Higher Education Courses: Transformative Strategies

Teaching/Learning can be a mutual journey in higher education. It requires more than wanting to approach teaching and learning differently. Our schema about power and teaching must be addressed. It is not a simple thing to tease out what part of submission in learning is vital to gaining mastery and learning to think deeply and critically, and what part is inhumane. It also requires a complex skill set for ourselves and for students that must be experienced and embraced by us, then taught and practiced. It is a complex change full of excitement and cognitive as well as personal challenges. Can we allow teaching and learning to become inseparable parts of a greater whole? Constructive teaching in higher education is not just about our ability to transcend the moment but the mutual journey, all participants teaching and learning that is the miracle

Schema and Enhanced Teaching/Learning

Recent research advances offer new perspectives on teaching and learning. Minds are complex personality connected, emotion laden entities. The inclusion of schema could support these findings and provide insights into why we need to focus on differentiated instructional and teaching practices that empower students. The paper concludes with suggestions for retooling that will honor these newest findings about how we learn

“We should have different voices with different perspectives”

This article is by Polis Summer School student Bonny Astor on the guest talk given by Samantha Asumadu (@honestlyAbroad) founder of Media Diversified (@WritersofColour) Samantha Asumadu – founder of Media Diversified – is admittedly combative on social media; but she’s also extremely effective

The Ape-men of Mobongu

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Biomass estimation as a function of vertical forest structure and forest height. Potential and limiations for remote sensing (radar and LiDAR)

Forest biomass stock, spatial distribution and dynamics are unknown parameters for many regions of the world. Today’s information is largely based on ground measurements on a plot basis without coverage in many remote regions that are fundamental for the global carbon cycle. Thus, a method capable of quantifying biomass by means of Remote Sensing (RS) could help to reduce these uncertainties and contribute to a better understanding of it. In this study the capacity to improve the estimation of above-ground biomass (AGB) with a new approach based on forest vertical structure and its potential to improve RS estimations is analyzed. Height to biomass allometry allows biomass estimations from remote sensing systems capable to resolve forest height (LiDAR and polarimetric SAR interferometry (Pol-InSAR)). However, this approach meets its limitations for forest ecosystems under changing conditions in density and structure. To improve biomass estimation accuracy, additional parameters need to be measured. Pol-InSAR and LiDAR allow getting besides forest height vertical backscattering profiles which are connected to forest vertical structure. Thus, due to the relation between structural parameters and AGB expressed by the Structure to Biomass allometry, AGB can be potentially inverted from these systems. The best characterization of forest vertical structure is obtained using the Legendre polynomials. Biomass profiles can be then characterized by the decomposition into a set of Legendre-Fourier basis functions. This method is able to accurately reconstruct vertical biomass profiles with low frequency features. Vertical backscattering profiles are strongly dependent on the sensor used as the resulting profiles are very sensitive to the wavelength and system geometry. E.g. LiDAR profiles are more sensitive to leaves and crowns while Pol-InSAR tends to reconstruct more the woody compartments (stems and branches). In this study, vertical backscattering profiles from short footprint airborne LiDAR and Pol-InSAR data are evaluated for their potential to reconstruct vertical forest structure. With the Legendre decomposition it is possible to parameterize the vertical backscattering profiles and relate them to forest biomass; even though for each remote sensing system different calibration methodologies must be derived. A first step is achieved using the calibration of backscattering signal with known biomass levels showing optimum results. In order to reduce the need of known parameters a new calibration methodology that exploits height to biomass allometric relations has been derived. Inversions using this methodology are tested for LiDAR and SAR profiles showing good correlations for an optimum subset of samples. As each system (frequency) is sensitive to certain biomass components an underestimation is generally expected. Research in this area is ongoing and will be presented with special focus on each system capacity to reconstruct forest vertical biomass distribution for broader sets of samples

The Last Hurrah: Sterling Price\u27s Missouri Expedition of 1864

Last Chance for a Confederate Missouri: Sterling Price’s 1864 Campaign In the summer and fall of 1864 Confederate forces launched a final three-pronged invasion of Union held territory. In the East Jubal Early even reached the District of Columbia, attacking Fort Stevens on July 12, befor...