Robust Topology Design of Complex Infrastructure Systems

2015 ◽  
Author(s):  
Joseph R. Piacenza ◽  
Scott Proper ◽  
Mir Abbas Bozorgirad ◽  
Irem Y. Tumer ◽  
Christopher Hoyle
Keyword(s):  
System Performance ◽  
Topology Design ◽  
Cascading Failures ◽  
Stage Design ◽  
Infrastructure Systems ◽  
The North ◽  
Network Connection ◽  
Trade Offs ◽  
System Robustness ◽  
The Impact

Optimizing the topology of complex infrastructure systems can minimize the impact of cascading failures due to an initiating failure event. This paper presents a novel approach for the concept-stage design of complex infrastructure systems by integrating model-based design with network analysis to increase system robustness. This approach focuses on system performance after cascading has occurred, and examines design trade-offs of the resultant (or degraded) system state. In this research, robustness is defined as the invariability of system performance due to uncertain failure events. Where a robust network has the ability to meet minimum performance requirements despite the impact of cascading failures. This research is motivated by catastrophic complex infrastructure system failures such as the August 13th Blackout of 2003, highlighting the vulnerability of systems such as the North American Power Grid (NAPG). A mathematical model was developed using an adjacency matrix, where removing a network connection simulates uncertain failure events. Performance degradation is iteratively calculated as failures cascade throughout the system, and robustness is measured by the lack of performance variability over multiple cascading failure scenarios. Two case studies are provided: an extrapolated IEEE 14 test bus, and the Oregon State University campus power network. The overarching goal of this research is to understand key system design trade-offs between robustness, performance objectives, and cost. In addition, optimizing network topologies to mitigate performance loss during concept-stage design will enable system robustness.

scholarly journals Robust Topology Design of Complex Infrastructure Systems

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Joseph R. Piacenza ◽  
Scott Proper ◽  
Mir Abbas Bozorgirad ◽  
Christopher Hoyle ◽  
Irem Y. Tumer
Keyword(s):  
System Performance ◽  
Topology Design ◽  
Cascading Failures ◽  
State University ◽  
Infrastructure Systems ◽  
The North ◽  
Performance Requirements ◽  
Failure Event ◽  
Design Tradeoffs ◽  
The Impact

Optimizing the topology of complex infrastructure systems can minimize the impact of cascading failures due to an initiating failure event. This paper presents a model-based design approach for the concept-stage robust design of complex infrastructure systems, as an alternative to modern network analysis methods. This approach focuses on system performance after cascading has occurred and examines design tradeoffs of the resultant (or degraded) system state. In this research, robustness is classically defined as the invariability of system performance due to uncertain failure events, implying that a robust network has the ability to meet minimum performance requirements despite the impact of cascading failures. This research is motivated by catastrophic complex infrastructure system failures such as the August 13th Blackout of 2003, highlighting the vulnerability of systems such as the North American power grid (NAPG). A mathematical model was developed using an adjacency matrix, where removing network connections simulates uncertain failure events. Performance degradation is iteratively calculated as failures cascade throughout the system, and robustness is measured by the lack of performance variability over multiple cascading failure scenarios. Two case studies are provided: an extrapolated IEEE 14 test bus and the Oregon State University (OSU) campus power network. The overarching goal of this research is to understand key system design tradeoffs between robustness, performance objectives, and cost, and explore the benefits of optimizing network topologies during the concept-stage design of these systems (e.g., microgrids).

scholarly journals The Impact Of Lane Closures On Congestion And Reliability: A Case Study Of Toronto's Gardiner Expressway

2021 ◽  
Author(s):  
Christina Borowiec
Keyword(s):  
Big Data ◽  
Performance Indicators ◽  
System Performance ◽  
Policy Action ◽  
Methods Of Analysis ◽  
Trade Offs ◽  
Regression Framework ◽  
The Impact ◽  
Lane Closures

Usage of big data with before-after methods of analysis makes it possible to evaluate the effect of major transport investments on system performance. In employing before-after methods to investigate the impact of lane closures on congestion and travel reliability, changes and trade-offs in performance indicators are quantified and policy action effectiveness is evaluated. This is illustrated through a case study of two separate lane closure interventions on the Gardiner Expressway in Toronto, Ontario. Models using a regression framework were developed for the pre-, peri-, and post-closure test periods of the first intervention and pre- and peri-closure periods of the second intervention. Results suggest the impacts of policy actions on system performance are strong, and that congestion and travel reliability counterintuitively move in different directions. Reduced demand effects are observed, prompting discussion on how highways and congestion should be managed and whether or not municipalities should add capacity to regional assets.

scholarly journals The Impact Of Lane Closures On Congestion And Reliability: A Case Study Of Toronto's Gardiner Expressway

2021 ◽  
Author(s):  
Christina Borowiec
Keyword(s):  
Big Data ◽  
Performance Indicators ◽  
System Performance ◽  
Policy Action ◽  
Methods Of Analysis ◽  
Trade Offs ◽  
Regression Framework ◽  
The Impact ◽  
Lane Closures

Usage of big data with before-after methods of analysis makes it possible to evaluate the effect of major transport investments on system performance. In employing before-after methods to investigate the impact of lane closures on congestion and travel reliability, changes and trade-offs in performance indicators are quantified and policy action effectiveness is evaluated. This is illustrated through a case study of two separate lane closure interventions on the Gardiner Expressway in Toronto, Ontario. Models using a regression framework were developed for the pre-, peri-, and post-closure test periods of the first intervention and pre- and peri-closure periods of the second intervention. Results suggest the impacts of policy actions on system performance are strong, and that congestion and travel reliability counterintuitively move in different directions. Reduced demand effects are observed, prompting discussion on how highways and congestion should be managed and whether or not municipalities should add capacity to regional assets.

Robust Design of North American Power Grid to Mitigate Cascading Failures

2013 ◽  
Author(s):  
Joseph R. Piacenza ◽  
Irem Y. Tumer ◽  
John J. Fields ◽  
Mir Abbas Bozorgirad ◽  
Christopher Hoyle
Keyword(s):  
Transmission Line ◽  
Robust Design ◽  
North American ◽  
Power Grid ◽  
Cascading Failures ◽  
Total System ◽  
Design Strategies ◽  
American Power ◽  
Network Connection ◽  
Trade Offs

Catastrophic cascading system failures such as the August 13th Blackout of 2003 highlight the vulnerability of the North American power grid, and emphasize the need for research to mitigate failure events. The incorporation of robust design, the insensitivity of system performance in the presence of noise (or uncertainty) from both internal and external sources, into existing and future power grid design strategies can increase system reliability. This paper presents a high-level topological network approach to power grid robust optimization as a solution for designing against cascading system failure. A mathematical model was created representing a standard power grid network consisting of generation and demand nodes, as well as node connections based on actual topological transmission line relationships. Each node possesses unique power generation or demand attributes, and various network connection configurations are examined based on system demand requirements. In this model, failure events are initiated by the removal of a single network connection, and remaining loads are redistributed throughout the system. Cascading failure effects are captured when the existing network configuration cannot support the resulting demand load, and transmission line failures continue propagate until the system again reaches a steady state, based on remaining nodes and connections. The primary goal of this research is to facilitate an understanding of design trade-offs between system robustness and performance objectives. In this research, robustness is defined as the resilience to initiating faults, where a robust network has the ability to meet system generation requirements despite propagating network failures. Primary performance objectives are total system cost and the ability to satisfy network demand after a failure, while robustness is represented as the lack of variability in the amount of demand which is satisfied after a failure. By understanding network reactions due to cascading failures, as well as performance trade-offs required to mitigate these failures, reliability in power grid systems can be increased.

Minimizing the Impact of SCR Catalyst on Total Generating Cost Through Effective Catalyst Management

2004 ◽  
Author(s):  
James E. Staudt
Keyword(s):  
System Performance ◽  
Catalytic Reduction ◽  
Management Strategies ◽  
Nox Reduction ◽  
Analysis Tool ◽  
Predictive Tools ◽  
Trade Offs ◽  
Wide Range ◽  
Parasitic Load ◽  
The Impact

For coal-fired boilers equipped with Selective Catalytic Reduction (SCR) NOx reduction technology, direct catalyst cost contributes to a major operating expense. Decisions regarding catalyst management have other significant impacts to generating cost, including outage time and frequency and parasitic load. Strategies for minimizing the impact to total generating cost while preserving system performance — generally referred to as catalyst management — are receiving greater attention. Approaches to managing catalyst can vary widely. Therefore, analysis of catalyst management strategies requires accurate predictive tools for assessing SCR system performance that have the flexibility to address a wide range of scenarios. These predictive tools may also be used to investigate performance issues that facility operators may encounter. However, until recently, operators have not had access to these tools, except through catalyst suppliers or consultants. In this presentation, various catalyst management strategies will be examined. Using an analysis tool recently adopted by several power plant operators and SCR technology suppliers, we will illustrate how such a tool can be used to optimize a catalyst management strategy to minimize the total cost of generation. Comparisons of model results to measured SCR performance at operating facilities will be presented. The model will be used to show operating trade offs for SCR operating parameters, such as NOx reduction, ammonia slip, catalyst outage frequency, catalyst usage, and parasitic load under a variety of scenarios. We will also discuss how the tool can be used to diagnose operating problems.

Nachhaltigkeit im Wald – vor und hinter der Welle der Globalisierung | Sustainable Forest Management – In Front and Behind the Wave of Globalization

2000 ◽  
Vol 151 (12) ◽  
pp. 502-507
Author(s):  
Christian Küchli
Keyword(s):  
Forest Management ◽  
Cultural Landscape ◽  
Sustainable Forest Management ◽  
Essential Element ◽  
Specific Situation ◽  
The South ◽  
The North ◽  
Time Space ◽  
Starting Point ◽  
The Impact

Are there any common patterns in the transition processes from traditional and more or less sustainable forest management to exploitative use, which can regularly be observed both in central Europe and in the countries of the South (e.g. India or Indonesia)? Attempts were made with a time-space-model to typify those force fields, in which traditional sustainable forest management is undermined and is then transformed into a modern type of sustainable forest management. Although it is unlikely that the history of the North will become the future of the South, the glimpse into the northern past offers a useful starting point for the understanding of the current situation in the South, which in turn could stimulate the debate on development. For instance, the patterns which stand behind the conflicts on forest use in the Himalayas are very similar to the conflicts in the Alps. In the same way, the impact of socio-economic changes on the environment – key word ‹globalisation› – is often much the same. To recognize comparable patterns can be very valuable because it can act as a stimulant for the search of political, legal and technical solutions adapted to a specific situation. For the global community the realization of the way political-economic alliances work at the head of the ‹globalisationwave›can only signify to carry on trying to find a common language and understanding at the negotiation tables. On the lee side of the destructive breaker it is necessary to conserve and care for what survived. As it was the case in Switzerland these forest islands could once become the germination points for the genesis of a cultural landscape, where close-to-nature managed forests will constitute an essential element.

Healthcare System in the Arctic Zone of Russia. Known and Emerging Issues and Solutions to Them

2019 ◽  
pp. 3-20
Author(s):  
V.N. Leksin
Keyword(s):  
Metallurgical Industry ◽  
Healthcare Services ◽  
The Arctic ◽  
Russian Arctic ◽  
Arctic Zone ◽  
Shift Workers ◽  
The North ◽  
Medical Institutions ◽  
Emerging Issues ◽  
The Impact

The impact on healthcare organization on the territory of Russian Arctic of unique natural and climatic, demographic, ethnic, settlement and professional factors of influencing the health of population, constantly or temporarily living on this territory is studied. The necessity is substantiated of various forms and resource provision with healthcare services such real and potential patients of Arctic medical institutions, as representatives of indigenous small peoples of the North, workers of mining and metallurgical industry, military personnel, sailors and shift workers. In this connection a correction of a number of All-Russian normative acts is proposed.

A general practice provider federation in a mixed health economy in England: a case study investigation

2018 ◽  
Vol 68 (suppl 1) ◽  
pp. bjgp18X696929
Author(s):  
Jill Mitchell
Keyword(s):  
General Practice ◽  
Shared Vision ◽  
Health Economy ◽  
Structured Interviews ◽  
The North ◽  
Common Strategy ◽  
Common Purpose ◽  
Collaborative Working ◽  
The Impact

BackgroundThere is an emerging debate that general practice in its current format is out-dated and there is a requirement to move to a federated model of provision where groups of Practices come together. The emergence of federations has developed over the past 5 years but the factors that influence how federations develop and the impact of this new model is an under researched area.AimThe study explored the rationale around why a group of independent GP practices opted to pursue an alternative business venture and the benefits that this strategy offered.MethodA single organisational case study of a federation in the North of England was conducted between 2011–2016. Mixed methods data collection included individual and group semi-structured interviews and quantitative surveys.ResultsFederations promote collaborative working, relying on strategic coherence of multiple individual GP practices through a shared vision and common purpose. Findings revealed many complexities in implementing a common strategy across multiple independent businesses. The ability of the federation to gain legitimacy was two dimensional – externally and internally. The venture had mixed successes, but their approach to quality improvement proved innovative and demonstrated outcomes on a population basis. The study identified significant pressures that practices were experiencing and the need to seek alternative ways of working but there was no shared vision or inclination to relinquish individual practice autonomy.ConclusionOrganisational development support is critical to reform General Practice. Whether central funding through the GP Five Year Forward View will achieve the scale of change required is yet to be evidenced.

The Impact of Sanctions on North Korea’s Foreign Trade from the Perspective of the Comparative Advantage Theory

2019 ◽  
pp. 4-15
Author(s):  
I. A. Korgun ◽  
G. D. Toloraya
Keyword(s):  
Foreign Trade ◽  
Competitive Advantage ◽  
National Economy ◽  
North Korea ◽  
Rent Seeking ◽  
Economic Transformation ◽  
Global Trade ◽  
Negative Consequences ◽  
The North ◽  
The Impact

The presented study analyzes the opportunities for North Korea to capitalize on its competitive advantages in foreign trade in the context of sanctions.Aim. The study aims to identify mechanisms that allow North Korea to engage in foreign trade in circumvention of UN sanctions and to analyze their impact on the national economy.Tasks. The authors analyze the structure of North Korea’s national economy, its initial competitive advantage, identify the specific features of North Korea’s foreign trade in the context of sanctions, and determine the consequences of illicit trade in circumvention of sanctions for the national economy.Methods. This study uses an interdisciplinary approach that combines the classical theory of competitive advantage with the concept of rent seeking, with the concept of rent seeking and analysis of trade flows.Results. The study shows that, despite the restrictions imposed by sanctions, North Korea strives to make the most of its advantages, such as resource availability and cheap labor, in global trade. The country builds its own export-import chains in circumvention of sanctions. These chains are rather mobile, flexible, and controlled by the elite. As a result, benefits from trade that could be evenly distributed among the population are concentrated in the hands of a narrow segment of society. ‘Rent seeking’ makes it possible to formulate the negative consequences of these processes for the North Korean economy and the international community.Conclusions. Solving the North Korean issue requires an economic transformation in the country through the replacement of restrictive sanctions with more constructive ones. The exclusion of North Korea from open global trade leads to the country’s marginalization and impairs the transparency of international commodity flows.

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