The Urban Heat Island and Its Influence on Precipitation in Denver, Colorado

Anthropogenic modification of the climate is an unintended yet serious effect of urbanization and it is happening in every city across the globe in the form of the urban heat island. The purpose of this study was to see if Denver, Colorado exhibits evidence of an urban heat island using meteorological data and if there has been a change in precipitation amounts since the urbanization of the city. It was concluded that Denver, Colorado does have an urban heat island that varies seasonally throughout the year with an average magnitude of 3.57°C during the day and 3.82°C at night. The summer season exhibits the most prominent urban heat island of 4.22°C during the night. Overall, there has been a significant decrease in precipitation for the study area that can possibly be attributed to the urbanization of Denver. A non-significant but still noteworthy increase in precipitation in a small area downwind of southern Denver could be due to the urban heat island around the city

Continuous limits of residual neural networks in case of large input data

Residual deep neural networks (ResNets) are mathematically described as interacting particle systems. In the case of infinitely many layers the ResNet leads to a system of coupled system of ordinary differential equations known as neural differential equations. For large scale input data we derive a mean-field limit and show well-posedness of the resulting description. Further, we analyze the existence of solutions to the training process by using both a controllability and an optimal control point of view. Numerical investigations based on the solution of a formal optimality system illustrate the theoretical findings

Modelling the Spatial Dynamics of Culture Spreading in the Presence of Cultural Strongholds

Cultural competition has throughout our history shaped and reshaped the geography of boundaries between humans. Language and culture are intimately connected and linguists often use distinctive keywords to quantify the dynamics of information spreading in societies harbouring strong culture centres. One prominent example, which is addressed here, is Kyoto's historical impact on Japanese culture. We construct a first minimal model, based on shared properties of linguistic maps, to address the interplay between information flow and geography. In particular, we show that spreading of information over Japan in the pre-modern time can be described as a Eden growth process, with noise levels corresponding to coherent spatial patches of sizes given by a single days walk, and with patch-to-patch communication time comparable to the time between human generations.Comment: 5 pages, 4 figure

Proceedings of the Sixth Caldwell Conference, St. Catherines Island, Georgia, May 20-22, 2011.

494 pages : illustrations (some color), maps (some color) ; 26 cm. Conference sponsored by the American Museum of Natural History and the St. Catherines Island Foundation.Although this volume covers a broad range of temporal and methodological topics, the chapters are unified by a geographic focus on the archaeology of the Georgia Bight. The various research projects span multiple time periods (including Archaic, Woodland, Mississippian, and contact periods) and many incorporate specialized analyses (such as petrographic point counting, shallow geophysics, and so forth). The 26 contributors conducting this cutting-edge work represent the full spectrum of the archaeological community, including museum, academic, student, and contract archaeologists. Despite the diversity in professional and theoretical backgrounds, temporal periods examined, and methodological approaches pursued, the volume is unified by four distinct, yet interrelated, themes. Contributions in Part I discuss a range of analytical approaches for understanding time, exchange, and site layout. Chapters in Part II model coastal landscapes from both environmental and social perspectives. The third section addresses site-specific studies of late prehistoric architecture and village layout throughout the Georgia Bight. Part IV presents new and ongoing research into the Spanish mission period of this area. These papers were initially presented and discussed at the Sixth Caldwell Conference, cosponsored by the American Museum of Natural History and the St. Catherines Island Foundation, held on St. Catherines Island, Georgia, May 20-22, 2011. TABLE OF CONTENTS: Revising the ¹⁴C reservoir correction for St. Catherines Island, Georgia / David Hurst Thomas, Matthew C. Sanger, and Royce H. Hayes -- An assessment of coastal faunal data from Georgia and northeast Florida / Alexandra L. Parsons and Rochelle A. Marrinan -- Archaeological geophysics on St. Catherines Island : beyond prospection / Ginessa J. Mahar -- Paste variability and clay resource utilization at the Fountain of Youth site, St. Augustine, 8SJ31 / Ann S. Cordell and Kathleen A. Deagan -- Petrographic analysis of pottery and clay samples from the Georgia Bight : evidence of regional social interactions / Neill J. Wallis and Ann S. Cordell -- Past shorelines of the Georgia coast / Chester B. DePratter and Victor D. Thompson -- Coastal landscapes and their relationship to human settlement on the Georgia coast / John A. Turck and Clark R. Alexander -- The role of small islands in foraging economies of St. Catherines Island / Matthew F. Napolitano -- Ever-shifting landscapes : tracking changing spatial usage along coastal Georgia / Matthew C. Sanger -- A paleoeconomic model of the Georgia coast (4500-300 B.P.) / Thomas G. Whitley -- A survey of Irene phase architecture on the Georgia coast / Deborah A. Keene and Ervan G. Garrison -- Life and death on the Ogeechee : a view from the Redbird Creek village / Ryan O. Sipe -- Mission San Joseph de Sapala : mission-period archaeological research on Sapelo Island / Richard W. Jefferies and Christopher R. Moore -- The Guale landscape of Mission Santa Catalina de Guale : 30 years of geophysics at a Spanish colonial mission / Elliot H. Blair -- Missions San Buenaventura and Santa Cruz de Guadalquini : retreat from the Georgia coast / Keith H. Ashley, Vicki L. Rolland, and Robert L. Thunen -- Entangling events : the Guale coastal landscape and the Spanish missions / Victor D. Thompson, John A. Turck, Amanda D. Roberts Thompson, and Chester B. DePratter -- Island and coastal archaeology on the Georgia Bight / Scott M. Fitzpatrick

SIGNAL PROCESSING IN THE PRESENCE OF SIGNAL-DEPENDENT NOISE

QC 351 A7 no. 65The significance of signal-dependent noise is discussed. Particular emphasis is placed on the type of multiplicative noise present in the density variations in a photographic emulsion. A theoretical treatment of the effect of multiplicative noise on signal detection and signal discrimination problems is presented. Optimum test statistics are derived for processing a sampled message to detect the presence of a known signal. Multiplicative noise described by Poisson and Gaussian statistics is considered. The expressions are extended to include the two-signal discrimination problem. Two-dimensional signal fields in the presence of multiplicative noise are simulated in a computer and processed for optimum signal detection according to the two derived methods. These results are compared to the results of processing based on the assumption of stationary noise statistics. This comparison reveals that modest improvements (20% to 30% reduction in false alarm rate) are obtained when the signal-dependent nature of the noise statistics is considered. The effects of signal-to-noise ratio, signal structure, and changing background level are also investigated. An example of optimum signal discrimination using circles and squares as signals in multiplicative noise is reported. An improvement in the percentage of correctly identified signals is again observed when the proper test statistic is used. Two examples of signal filtering in the presence of signal-dependent noise are included. The first concerns the processing of a real star field to determine the location of weak stars. The second is an illustration of the signal information contained in the noise spectrum of a message recorded on a common photographic film.This title from the Optical Sciences Technical Reports collection is made available by the College of Optical Sciences and the University Libraries, The University of Arizona. If you have questions about titles in this collection, please contact [email protected]