Review: Monitoring situational awareness of smart grid cyber-physical systems and critical asset identification

Cyber-Physical Systems (CPSs) are becoming more automated and aimed to be as efficient as possible by enabling integration between their operations and Information Technology (IT) resources. In combination with production automation, these systems need to identify their assets and the correlation between them; any potential threats or failures alert the relevant user/department and suggest the appropriate remediation plan. Moreover, identifying critical assets in these systems is essential. With numerous research and technologies available, assessing IT assets nowadays can be straightforward to implement. However, there is one significant issue of evaluating operational technology critical assets since they have different characteristics, and traditional solutions cannot work efficiently. This study presents the necessary background to attain the appropriate approach for monitoring critical assets in CPSs' Situational Awareness (SA). Additionally, the study presents a broad survey supported by an in-depth review of previous works in three important aspects. First, it reviews the applicability of possible techniques, tools and solutions that can be used to collect detailed information from such systems. Secondly, it covers studies that were implemented to evaluate the criticality of assets in CPSs, demonstrates requirements for critical asset identification, explores different risks and failure techniques utilised in these systems and delves into approaches to evaluate such methods in energy systems. Finally, this paper highlights and analyses SA gaps based on existing solutions, provides future directions and discusses open research issues

Geomechanical Reservoir Model Calibration and Uncertainty Assessment from Microseismic Data

Hydraulic stimulation of low permeability rocks in unconventional reservoirs has been observed to trigger microearthquakes (MEQs). Triggering of the MEQ events has been linked to the pore pressure, temperature, and in-situ stress variations which result in crack initiation. The resulting clouds of micro-seismic events are believed to carry information about the underlying coupled flow, geomechanics, and thermal processes and hence rock hydraulic and geomechanical property distributions. We develop a probabilistic framework called stochastic seismicity-based reservoir characterization (SSBRC) to integrate microseismic events to infer reservoir property distributions. To model the geothermal reservoir stimulation, a fully coupled thermo-poroelastic finite element method (FEM) model has been developed to handle the coupled process of heat transport, fluid flow, and rock deformation. To simulate the stimulation process, an alternate simplistic approach is also acquired based on a major hypothesis that MEQ events are triggered by an increase in pore pressure. Based on this hypothesis, the distribution of the resulting microseismicity clouds can be viewed as monitoring data that carry important information about the spatial distribution of rock permeability. We apply the ensemble Kalman filter (EnKF) to integrate the resulting continuous seismicity map to estimate hydraulic and geomechanical property distributions. We demonstrate that the standard application of the EnKF with such large correlated datasets can result in substantial loss of ensemble spread. We investigate three alternative implementation methods to mitigate this issue. We first present the methodology proposed for MEQ data integration with the EnKF, followed by a number of examples of applying SSBRC to both forward modeling methods to illustrate the uncertainty underestimation effect when the standard EnKF is applied to large-scale seismicity density map data. We then discuss the proposed methods for improving the uncertainty quantification results and illustrate the effectiveness of these methods by applying them to a number of numerical examples. We also apply and extend the proposed microseismic data integration method to unconventional reservoir with horizontal well and multistage hydraulic fractures to characterize the reservoir and induced fractures. We also investigate the effect of variogram model uncertainty in the EnKF performance and propose a modified EnKF algorithm to handle the uncertainty in variogram parameters. We also develop a computationally efficient data assimilation procedure by employing a pseudo forecast method and geological model clustering method along with EnKF. By a set of numerical experiments, we show how the proposed fast history matching method is successful in preserving the ensemble spread and expediting the integration procedure

The transitional-probability Markov chain versus traditional indicator methods for modeling the geotechnical categories in a test site.

Das Ziel der vorliegenden Arbeit war die Erstellung eines dreidimensionalen Untergrundmodells der Region Göttingen basierend auf einer geotechnischen Klassifikation der unkosolidierten Sedimente. Die untersuchten Materialen reichen von Lockersedimenten bis hin zu Festgesteinen, werden jedoch in der vorliegenden Arbeit als Boden, Bodenklassen bzw. Bodenkategorien bezeichnet. Diese Studie evaluiert verschiedene Möglichkeiten durch geostatistische Methoden und Simulationen heterogene Untergründe zu erfassen. Derartige Modellierungen stellen ein fundamentales Hilfswerkzeug u.a. in der Geotechnik, im Bergbau, der Ölprospektion sowie in der Hydrogeologie dar. Eine detaillierte Modellierung der benötigten kontinuierlichen Parameter wie z. B. der Porosität, der Permeabilität oder hydraulischen Leitfähigkeit des Untergrundes setzt eine exakte Bestimmung der Grenzen von Fazies- und Bodenkategorien voraus. Der Fokus dieser Arbeit liegt auf der dreidimensionalen Modellierung von Lockergesteinen und deren Klassifikation basierend auf entsprechend geostatistisch ermittelten Kennwerten. Als Methoden wurden konventionelle, pixelbasierende sowie übergangswahrscheinlichkeitsbasierende Markov-Ketten Modelle verwendet. Nach einer generellen statistischen Auswertung der Parameter wird das Vorhandensein bzw. Fehlen einer Bodenkategorie entlang der Bohrlöcher durch Indikatorparameter beschrieben. Der Indikator einer Kategorie eines Probepunkts ist eins wenn die Kategorie vorhanden ist bzw. null wenn sie nicht vorhanden ist. Zwischenstadien können ebenfalls definiert werden. Beispielsweise wird ein Wert von 0.5 definiert falls zwei Kategorien vorhanden sind, der genauen Anteil jedoch nicht näher bekannt ist. Um die stationären Eigenschaften der Indikatorvariablen zu verbessern, werden die initialen Koordinaten in ein neues System, proportional zur Ober- bzw. Unterseite der entsprechenden Modellschicht, transformiert. Im neuen Koordinatenraum werden die entsprechenden Indikatorvariogramme für jede Kategorie für verschiedene Raumrichtungen berechnet. Semi-Variogramme werden in dieser Arbeit, zur besseren Übersicht, ebenfalls als Variogramme bezeichnet. IV Durch ein Indikatorkriging wird die Wahrscheinlichkeit jeder Kategorie an einem Modellknoten berechnet. Basierend auf den berechneten Wahrscheinlichkeiten für die Existenz einer Modellkategorie im vorherigen Schritt wird die wahrscheinlichste Kategorie dem Knoten zugeordnet. Die verwendeten Indikator-Variogramm Modelle und Indikatorkriging Parameter wurden validiert und optimiert. Die Reduktion der Modellknoten und die Auswirkung auf die Präzision des Modells wurden ebenfalls untersucht. Um kleinskalige Variationen der Kategorien auflösen zu können, wurden die entwickelten Methoden angewendet und verglichen. Als Simulationsmethoden wurden "Sequential Indicator Simulation" (SISIM) und der "Transition Probability Markov Chain" (TP/MC) verwendet. Die durchgeführten Studien zeigen, dass die TP/MC Methode generell gute Ergebnisse liefert, insbesondere im Vergleich zur SISIM Methode. Vergleichend werden alternative Methoden für ähnlichen Fragestellungen evaluiert und deren Ineffizienz aufgezeigt. Eine Verbesserung der TP/MC Methoden wird ebenfalls beschrieben und mit Ergebnissen belegt, sowie weitere Vorschläge zur Modifikation der Methoden gegeben. Basierend auf den Ergebnissen wird zur Anwendung der Methode für ähnliche Fragestellungen geraten. Hierfür werden Simulationsauswahl, Tests und Bewertungsysteme vorgeschlagen sowie weitere Studienschwerpunkte beleuchtet. Eine computergestützte Nutzung des Verfahrens, die alle Simulationsschritte umfasst, könnte zukünftig entwickelt werden um die Effizienz zu erhöhen. Die Ergebnisse dieser Studie und nachfolgende Untersuchungen könnten für eine Vielzahl von Fragestellungen im Bergbau, der Erdölindustrie, Geotechnik und Hydrogeologie von Bedeutung sein.Having a plenty of geotechnical records and measurements in Göttingen area, a subsurface three-dimensional model of the unconsolidated sediment classes was required. To avoid the repetition of the long expressions, from this point on, these unconsolidated materials which vary from the loose sediments to the hard rocks has been termed as “soil”, “category”, “soil class” or “soil category”. These sediments which are intermediate between the hard bed-rock and loose sediments (soils) were categorized based on the geotechnical norms of the DIN 18196. In this study, the aim was to evaluate the capabilities of the application of geostatistical estimation and simulation methods in modeling the subsurface heterogeneities, especially about the geotechnical soil classes. Such a heterogeneity modeling is a crucial step in a variety of applications such as geotechnics, mining, petroleum engineering, hydrogeology, and so on. For an accurate modeling of the essential continuous parameters, such as the ore grades, porosity, permeability, and hydraulic conductivity of a porous medium, the precise delineation of the facies or soil category boundaries prior to any modeling step is necessary. The focus of this study is on a three-dimensional modeling and delineation of the unconsolidated materials of the subsurface using the geostatistical methods. The applied geostatistical methods here consisted of the pixel-based conventional and transition-probability Markov chain-based geostatistical methods. After a general statistical evaluation of different parameters, the presence and absence of each category along the sampling boreholes was coded by new parameters called indicators. The indicator of a category in a sampling point is one (1) when the category exists and zero (0) when it is absent. Some intermediate states can also be found. For instance, the indicator of a two categories can be assigned to 0.5 when both the categories probably exist at that location but it is unsure which one exactly presents at that location. Moreover, to increase the stationarity characteristic of the indicator variables, the initial coordinates were transformed into a new system proportional to the top and bottom of the modeled layer as a first modeling step. In the new space, to conduct the conventional geostatistical modeling, the indicator variograms were calculated and modeled for each category in a variety of directions. In this text, for easier reference to the semi-variograms, the term variogram has been applied instead. II Using the indicator kriging, the probability of the occurrence of each category at each modeling node was estimated. Based on the estimated probabilities of the existence of each soil category from the previous stage, the most probable category was assigned to each modeling point then. Moreover, the employed indicator variogram models and indicator kriging estimation parameters were validated and improved. The application of a less number of samples were also tested and suggested for similar cases with a comparable precision in the results. To better reflect the fine variations of the categories, the geostatistical simulation methods were applied, evaluated, and compared together. The employed simulation methods consisted of the sequential indicator simulation (SISIM) and the transition probability Markov chain (TP/MC). The conducted study here suggested that the TP/MC method could generate satisfactory results especially compared to those of the SISIM method. Some reasons were also brought and discussed for the inefficiency of the other facies modeling alternatives for this application (and similar cases). Some attempts for improving the TP/MC method were also conducted and a number of results and suggestions for further researches were summarized here. Based on the achieved results, the application of the TP/MC methods was advised for the similar problems. Besides, some simulation selection, tests, and assessment frameworks were proposed for analogous applications. In addition, some instructions for future studies were made. The proposed framework and possibly the improved version of it could be further completed by creating a guided computer code that would contain all of the proposed steps. The results of this study and probably its follow-up surveys could be of an essential importance in a variety of important applications such as geotechnics, hydrogeology, mining, and hydrocarbon reservoirs

Handbook of Mathematical Geosciences

This Open Access handbook published at the IAMG's 50th anniversary, presents a compilation of invited path-breaking research contributions by award-winning geoscientists who have been instrumental in shaping the IAMG. It contains 45 chapters that are categorized broadly into five parts (i) theory, (ii) general applications, (iii) exploration and resource estimation, (iv) reviews, and (v) reminiscences covering related topics like mathematical geosciences, mathematical morphology, geostatistics, fractals and multifractals, spatial statistics, multipoint geostatistics, compositional data analysis, informatics, geocomputation, numerical methods, and chaos theory in the geosciences

Annual Report of the University, 1999-2000, Volumes 1-4

The Robert O. Anderson School and Graduate School of Management at The University of New Mexico Period of Report: July 1, 1999 to June 30, 2000 Submitted by Howard L. Smith, Dean The Anderson Schools of Management is divided into four distinct divisions- the Department of Accounting; the Department of Finance, International and Technology Management; the Department of Marketing, Information and Decision Sciences; and the Department of Organizational Studies. This structure provides an opportunity for The Anderson Schools to develop four distinct areas of excellence, proven by results reported here. I. Significant Developments During the Academic Year The Anderson Schools of Management • As a result of the multi-year gift from the Ford Motor Company, completed renovation of The Schools\u27 Advisement and Placement Center, as well as all student organization offices. • The Ford gift also provided for $100,000 to support faculty research, case studies and course development. • The Schools revised the MBA curriculum to meet the changing needs of professional, advanced business education. • The Schools updated computer laboratory facilities, with the addition of a 45-unit cluster for teaching and student work. • The faculty and staff of The Schools furthered outreach in economic development activities by participating directly as committee members and leaders in the cluster workgroups of the Next Generation Economy Initiative. • The faculty, staff and students of The Schools contributed to the development of the Ethics in Business Awards; particularly exciting was the fact that all nominee packages were developed by student teams from The Anderson Schools. • The Schools continue to generate more credit hours per faculty member than any other division of the UNM community. The Accounting Department • Preparation and presentation of a progress report to accrediting body, the AACSB. The Department of Finance, International and Technology Management • The Department continued to focus on expansion of the Management of Technology program as a strategic strength of The Schools. The Department of Marketing. Information and Decision Sciences • Generated 9022 credit hours, with a student enrollment of 3070. The Department of Organizational Studies • Coordinated the 9th UNM Universidad de Guanajuato (UG) Mexico Student Exchange