The Role of Prior Assumptions for Leak Localisation in Water Networks with Uncertainties

Author(s):  
Caroline Blocher ◽  
Filippo Pecci ◽  
Ivan Stoianov

Abstract Hydraulic model-based leak (burst) localisation in water networks is a challenging problem due to uncertainties, the limited number of hydraulic measurements, and the wide range of leak properties. In this study, we investigate the use of prior assumptions to improve the leak localisation in the presence of model uncertainties. For example, 𝓁2-regularisation relies on the assumption that the Euclidean norm of the leak coefficient vector should be minimised. This approach is compared with a method based on the sensitivity matrix, which assumes the existence of only a single leak. We show that while applying the sensitivity matrix often yields a better estimate of the leak location in single leak scenarios, the 𝓁2-regularisation successfully identifies a leak search area for pinpointing the accurate leak location. Furthermore, we demonstrate that the additional error introduced by a quadratic approximation of the Hazen-Williams formula for the solution of the localisation problem is negligible given the uncertainties in Hazen-Williams resistance coefficients in operational water network models.

Author(s):  
Caroline Blocher ◽  
Filippo Pecci ◽  
Ivan Stoianov

AbstractHydraulic model-based leak (burst) localisation in water distribution networks is a challenging problem due to a limited number of hydraulic measurements, a wide range of leak properties, and model and data uncertainties. In this study, prior assumptions are investigated to improve the leak localisation in the presence of uncertainties. For example, $$\ell _2$$ ℓ 2 -regularisation relies on the assumption that the Euclidean norm of the leak coefficient vector should be minimised. This approach is compared with a method based on the sensitivity matrix, which assumes the existence of only a single leak. The results show that while the sensitivity matrix method often yields a better leak location estimate in single leak scenarios, the $$\ell _2$$ ℓ 2 -regularisation successfully identifies a search area for pinpointing the accurate leak location. Furthermore, it is shown that the additional error introduced by a quadratic approximation of the Hazen-Williams formula for the solution of the localisation problem is negligible given the uncertainties in Hazen-Williams resistance coefficients in operational water network models.


2018 ◽  
Author(s):  
Jake P. Stroud ◽  
Mason A. Porter ◽  
Guillaume Hennequin ◽  
Tim P. Vogels

AbstractMotor cortex (M1) exhibits a rich repertoire of activities to support the generation of complex movements. Although recent neuronal-network models capture many qualitative aspects of M1 dynamics, they can generate only a few distinct movements. Additionally, it is unclear how M1 efficiently controls movements over a wide range of shapes and speeds. We demonstrate that simple modulation of neuronal input–output gains in recurrent neuronal-network models with fixed architecture can dramatically reorganize neuronal activity and thus downstream muscle outputs. Consistent with the observation of diffuse neuromodulatory projections to M1, we show that a relatively small number of modulatory control units provide sufficient flexibility to adjust high-dimensional network activity using a simple reward-based learning rule. Furthermore, it is possible to assemble novel movements from previously learned primitives, and one can separately change movement speed while preserving movement shape. Our results provide a new perspective on the role of modulatory systems in controlling recurrent cortical activity.


2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.


2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.


Author(s):  
C. Claire Thomson

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.


2020 ◽  
pp. 102-109
Author(s):  
Svetlana Alekseevna Raschetina ◽  

Relevance and problem statement. Modern unstable society is characterized by narrowing the boundaries of controlled socialization and expanding the boundaries of spontaneous socialization of a teenager based on his immersion in the question arises about the importance of the family in the process of socialization of a teenager in the conditions of expanding the space of socialization. There is a need to study the role of the family in this process, to search, develop and test research methods that allow us to reveal the phenomenon of socialization from the side of its value characteristics. The purpose and methodology of the study: to identify the possibilities of a systematic and anthropological methodology for studying the role of the family in the process of socialization of adolescents in modern conditions, testing research methods: photo research on the topic “Ego – I” (author of the German sociologist H. Abels), profile update reflexive processes (by S. A. Raschetina). Materials and results of the study. The study showed that for all the problems that exist in the family of the perestroika era and in the modern family, it acts for a teenager as a value and the first (main) support in the processes of socialization. The positions well known in psychology about the importance of interpersonal relations in adolescence for the formation of attitudes towards oneself as the basis of socialization are confirmed. Today, the frontiers of making friends have expanded enormously on the basis of Internet communication. The types of activities of interest to a teenager (traditional and new ones related to digitalization) are the third pillar of socialization. Conclusion. The “Ego – I” method of photo research has a wide range of possibilities for quantitative and qualitative analysis of the socialization process to identify the value Pillars of this process.


Author(s):  
Simon Goldhill

How did the Victorians engage with the ancient world? This book is an exploration of how ancient Greece and Rome influenced Victorian culture. Through Victorian art, opera, and novels, the book examines how sexuality and desire, the politics of culture, and the role of religion in society were considered and debated through the Victorian obsession with antiquity. Looking at Victorian art, it demonstrates how desire and sexuality, particularly anxieties about male desire, were represented and communicated through classical imagery. Probing into operas of the period, the book addresses ideas of citizenship, nationalism, and cultural politics. And through fiction—specifically nineteenth-century novels about the Roman Empire—it discusses religion and the fierce battles over the church as Christianity began to lose dominance over the progressive stance of Victorian science and investigation. Rediscovering some great forgotten works and reframing some more familiar ones, the book offers extraordinary insights into how the Victorian sense of antiquity and our sense of the Victorians came into being. With a wide range of examples and stories, it demonstrates how interest in the classical past shaped nineteenth-century self-expression, giving antiquity a unique place in Victorian culture.


2016 ◽  
Vol 1 (1) ◽  
pp. 4
Author(s):  
Marymol Koshy ◽  
Bushra Johari ◽  
Mohd Farhan Hamdan ◽  
Mohammad Hanafiah

Hypertrophic cardiomyopathy (HCM) is a global disease affecting people of various ethnic origins and both genders. HCM is a genetic disorder with a wide range of symptoms, including the catastrophic presentation of sudden cardiac death. Proper diagnosis and treatment of this disorder can relieve symptoms and prolong life. Non-invasive imaging is essential in diagnosing HCM. We present a review to deliberate the potential use of cardiac magnetic resonance (CMR) imaging in HCM assessment and also identify the risk factors entailed with risk stratification of HCM based on Magnetic Resonance Imaging (MRI).


2019 ◽  
Author(s):  
Andrew Romine ◽  
Kin Yang ◽  
Malkanthi Karunananda ◽  
Jason Chen ◽  
Keary Engle

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.


2020 ◽  
Vol 26 (1) ◽  
pp. 86-93
Author(s):  
D. V. Slivinsky ◽  
I. A. Fomina ◽  
D. G. Menshikh

The presented study determines the role of business aviation in the modern economy and examines the specific features of its development in Russia.Aim. The study aims to analyze the development of business aviation in Russia and its correlation with economic development in general.Tasks. The authors determine the benefits of business aviation as a business tool, examine the specific features of the Russian business aviation market and problems of its development, and identify factors that affect the development of business aviation in Russia.Methods. This study uses the methods of comparative and retrospective analysis, cross-country comparison, systems approach, and expert analytics.Results. Business aviation is a new segment of civil aviation for Russia. Therefore, it is advisable to rely on foreign practices in the management of its development. In many countries, business aviation is a separate industry that specializes in providing transport services to a wide range of corporate clients and/or individuals. The development of this industry is associated with the economic growth rate and the development level of the national economy, and also depends on the national institutional specifics. This study describes the specific features of development of business aviation in Russia and problems arising in the organization and management of this type of business.Conclusions. The authors develop a system of factors affecting the development of business aviation in Russia, describe the major problems of this industry, and propose solutions. The results of this study can be used in the development (adjustment) of business aviation development strategies in Russia both at the industrial and corporate level, and in the implementation of the national policy in this field.


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