An Initial Framework Assessing the Safety of Complex Systems

Trabajo presentado en la Conference on Complex Systems, celebrada online del 7 al 11 de diciembre de 2020.Atmospheric blocking events, that is large-scale nearly stationary atmospheric pressure patterns, are often associated with extreme weather in the mid-latitudes, such as heat waves and cold spells which have significant consequences on ecosystems, human health and economy. The high impact of blocking events has motivated numerous studies. However, there is not yet a comprehensive theory explaining their onset, maintenance and decay and their numerical prediction remains a challenge. In recent years, a number of studies have successfully employed complex network descriptions of fluid transport to characterize dynamical patterns in geophysical flows. The aim of the current work is to investigate the potential of so called Lagrangian flow networks for the detection and perhaps forecasting of atmospheric blocking events. The network is constructed by associating nodes to regions of the atmosphere and establishing links based on the flux of material between these nodes during a given time interval. One can then use effective tools and metrics developed in the context of graph theory to explore the atmospheric flow properties. In particular, Ser-Giacomi et al. [1] showed how optimal paths in a Lagrangian flow network highlight distinctive circulation patterns associated with atmospheric blocking events. We extend these results by studying the behavior of selected network measures (such as degree, entropy and harmonic closeness centrality)at the onset of and during blocking situations, demonstrating their ability to trace the spatio-temporal characteristics of these events.This research was conducted as part of the CAFE (Climate Advanced Forecasting of sub-seasonal Extremes) Innovative Training Network which has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 813844

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

Housing quality and lost (public) space in Croatia

IN ENGLISH: In the post-socialist period and within the current social transition context, urban and rural Croatia has, just like other transition countries, experienced many changes in the social structure and space. One example is the housing quality which is a replica of the situation in the Croatian society and has also undergone some major changes. Socially oriented housing construction co-financed by the state and the cities is in an unfavourable position compared to private housing construction. In the last twenty years the amount of the social housing construction has been only a minor part of the total contruction work in the country. For instance, out of nine newly planned residential housing developments in Zagreb, the capital city, only three have been completed and the work on the rest of them has stopped and is unlikely to continue. Private construction work prevails especially on the edge of the city and is characterised by high density housing. This type of housing construction doesn't benefit the majority of citizens in search of accommodation (price per square meter is too high, low-quality building). There is also a big problem of the community facilities (primary and secondary infrastructure, schools, kindergartens, playgrounds, green areas, sidewalks, public transport etc.). The existing globalisation-transition circumstances of the Croatian society corroborate the fact which experts of various profiles often point out: ignoring the process of (urban) planning will irreparably damage the space. The city transformation shows the absence of comprehensive urban planning which results in an ever increasing number of random buildings which do not fit in the surroundings. This leads up to yet another important issue – the shrinking and, in some cases, disappearance of public space which becomes the “lost space“. In recent years there has been a lot of building in the city core and on the edge which does not quite fit in the existing urban structure, image or the skyline of the city. The current situation in the process of planning can be characterized as a conflict and imbalance between the powerful actors (mostly political and economic) and less powerful actors (mostly professional and civil). The actors who have the political power and influence and the ones who possess the capital are forming an “alliance” between two important layers of the social structure. The lack of civil and professional actors, “lost spatial actors”, and therefore of civic aggregation is also present and that is also the cause of public space “disappearance” and undermined process of public participation. --------------- IN CROATIAN: U postsocijalističkom razdoblju i trenutnom tranzicijskom kontekstu urbana i ruralna Hrvatska su, kao i ostale tranzicijske zemlje, doživjele mnoge promjene u društvenoj strukturi i samom prostoru. Na primjeru kvalitete stanovanja kao replike stanja u hrvatskom društvu mogu se vidjeti značajne promjene. Društveno usmjerena stambena izgradnja sufinancirana od strane države i gradova je stoga rjeđa i u nepovoljnijoj je situaciji prema privatnoj stanogradnji. Zadnjih dvadeset godina udjel socijalne stambene gradnje je zanemariv u ukupnoj izgradnji na razini zemlje. Primjerice, od devet planiranih stambenih naselja izgrađenih po modelu POS-a u Zagrebu samo su tri i završena. Na ostalima je proces gradnje zastao i ne čini se da će se privesti kraju. Privatna je gradnje prisutnija, posebno na rubovima grada, a obilježava je visoka gustoća gradnje. Ovakav tip gradnje ne odgovara većini stanovnika koji su u procesu potražnje stambene nekretnine (visoka cijena kvadratnog metra, a slaba kvaliteta gradnje). Postoji također i problem nedostatne opremljenosti susjedstva (primarna i sekundarna infrastruktura, škole, vrtići, igrališta, zelene površine, pješačke staze, javni transport itd.). Navedene globalizacijsko-tranzicijske okolnosti hrvatskog društva potvrđuju ono što eksperti različitih profila ističu, a to je da će ignoriranje procesa (urbanog) planiranja nepovratno uništiti prostor gradova. Ovakve transformacije pokazuju nedostatak sustavnog urbanog planiranja što rezultira sve većim brojem zgrada koje se ne uklapaju u neposrednu okolinu. To nadalje dovodi do drugog važnog aspekta – smanjivanja i u nekim slučajevima, nestanka javnog prostora koji postaje „izgubljeni prostor“. Posljednjih je godina izgrađen velik broj zgrada, i u središtu i na rubovima grada, koje se ne uklapaju u postojeću urbanu strukturu, izgled ili vizuru grada. Ovakvu situaciju obilježavaju sukob i neravnoteža između moćnijih društvenih aktera (većinom političkih i ekonomskih) i onih manje moćnih (većinom profesionalnih i civilnih). Politički i ekonomski akteri se često povezuju u „savez“ dvaju najjačih u društvenoj strukturi. S druge strane nedostatak utjecaja civilnih i profesionalnih aktera kao „izgubljenih prostornih aktera“ dovodi do „nestanka“ javnih prostora te smanjenja važnosti procesa participacije (sudjelovanja javnosti)

Knowledge for Governance

This open access book focuses on theoretical and empirical intersections between governance, knowledge and space from an interdisciplinary perspective. The contributions elucidate how knowledge is a prerequisite as well as a driver of governance efficacy, and conversely, how governance affects the creation and use of knowledge and innovation in geographical context. Scholars from the fields of anthropology, economics, geography, public administration, political science, sociology, and organization studies provide original theoretical discussions along these interdependencies. Moreover, a variety of empirical chapters on governance issues, ranging from regional and national to global scales and covering case studies in Australia, Europe, Latina America, North America and South Africa demonstrate that geography and space are not only important contexts for governance that affect the contingent outcomes of governance blueprints. Governance also creates spaces. It affects the geographical confines as well as the quality of opportunities and constraints that actors enjoy to establish legitimate and sustainable ways of social and environmental co-existence

MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

Generalized averaged Gaussian quadrature and applications

A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal

College of Arts and Sciences

Cornell University Courses of Study Vol. 95 2003/200