Operation Of Infrastructure Systems Research Articles

Optimizing the robustness of higher-low order coupled networks.

Enhancing the robustness of complex networks is of great practical significance as it ensures the stable operation of infrastructure systems. We measure its robustness by examining the size of the largest connected component of the network after initial attacks. However, traditional research on network robustness enhancement has mainly focused on low-order networks, with little attention given to higher-order networks, particularly higher-low order coupling networks(the largest connected component of the network must exist in both higher-order and low-order networks). To address this issue, this paper proposes robust optimization methods for higher-low order coupled networks based on the greedy algorithm and the simulated annealing algorithm. By comparison, we found that the simulated annealing algorithm performs better. The proposed method optimizes the topology of the low-order network and the higher-order network by randomly reconnecting the edges, thereby enhancing the robustness of the higher-order and low-order coupled network. The experiments were conducted on multiple real networks to evaluate the change in the robustness coefficient before and after network optimization. The results demonstrate that the proposed method can effectively improve the robustness of both low-order and higher-order networks, ultimately enhancing the robustness of higher-low order coupled networks.

The value of flexibility and sequential decision-making in maintenance strategies of infrastructure systems

The operation of infrastructure systems is a long-lasting managerial endeavour in which decision makers need to adapt to a changing environment and new events that result from an uncertain future. One of the essential aspects of infrastructure operation is maintenance, which guarantees acceptable operation standards for this kind of projects, which are normally subjected to several deterioration mechanisms. This paper discusses the concept of flexibility in maintenance planning for infrastructure systems and presents a model that allows to capture the value of flexible decisions in the context of sequential maintenance decisions. First, it presents an approach for addressing the sequential decision-making process of maintenance in infrastructure through an application of stochastic programming. Then, it describes and formulates the valuation of maintained systems under uncertainty through Real Options. Finally, the proposed methodology is studied through an illustrative example that shows the advantages of the proposed approach and highlights the role of flexibility in maintenance planning.

Comparative infrastructural modalities: Examining spatial strategies for Melbourne, Auckland and Vancouver

Infrastructure systems are critical to support sustainable and equitable urbanisation, and infrastructure is becoming more prominent within urban spatial strategies. However, the fragmented governance and delivery of spatial plans and infrastructure projects create a challenging environment to embed planning goals across the planning, delivery and operation of infrastructure systems. There is significant uncertainty around future needs and the complex ways that infrastructures influence socio-spatial relations and political-economic processes. Additionally, fragmented knowledge of infrastructure across different disciplines undermines the development of robust planning strategies. Comparative analysis of strategic spatial plans from Auckland, Melbourne and Vancouver examines how infrastructures are instrumentalised to support planning goals. Across the three cases, the analysis identified four common infrastructural modalities: rescaling socio-spatial relations through targeted intensification, intra-urban mobility upgrades and containment boundaries; re-localising socio-spatial relations to the suburban scale with ‘complete communities’; protection of ‘gateway’ precincts; and local planning provisions to support housing affordability. By examining infrastructure through a theoretical framework for suburban infrastructures, this analysis revealed how infrastructures exert agency as artefacts shaping socio-spatial relations and through the internalisation of political-economic processes. Each modality mobilised infrastructure to support goals of global competitiveness, economic growth and ‘liveability’. Findings suggest that spatial strategies should take a user-focused approach to infrastructure to meet the needs of diverse urban populations, and engage directly with the modes of infrastructure project delivery to embed planning goals across design, delivery and operations stages. Stronger institutional mandates to control land-use and provide affordable housing would improve outcomes in these city-regions.

Maintenance and Operation of Infrastructure Systems: Review

AbstractInfrastructure management plays an important role in sustainable development and is essential for the evaluation of the socioeconomic feasibility of existing projects and the development of new ones. This paper presents a review of key aspects involved in the maintenance and operation of infrastructure under uncertainty. It discusses the main conceptual and theoretical principles and guides the reader through different aspects of the problem by offering a large set of state-of-the-art references. Although the paper does not provide a comprehensive description of all maintenance methods and policies available in the literature, it critically reviews the main approaches. The concepts presented and discussed in this paper provide the basis to build models that can be used for making better decisions for maintaining and operating infrastructure systems.

Developing an agent-based hierarchical modeling approach to assess human performance of infrastructure systems

During the last decade, research works related to modeling and simulation of infrastructure systems have primarily focused on the performance of their technical factors, almost ignoring the importance of non-technical factors of these systems, e.g., human operators, consumers. In contrast, the human operator of infrastructure systems has become an essential part in daily operation and in ensuring the security and reliability of the system. In some of the most significant technological incidents of the past century, human error has played a major role. Therefore, developing a modeling approach that is capable of assessing the human performance in a comprehensive way has become crucial. In this paper, an agent-based hierarchical modeling approach is proposed, which aims at the explicit modeling of the impacts of human performance on the operation of infrastructure systems. Within this approach, the cognition component plays a major role. For this purpose, an analytical method based on the Cognitive Reliability Error Analysis Method (CREAM) is developed using a knowledge-based approach. The proposed modeling approach is a pilot work exploring possibilities of simulating performance of human factors in infrastructure systems. The applicability of this modeling approach is demonstrated by a validation experiment using the electric power supply system as an exemplary system.

Integrating Decentralized Rainwater Management in Urban Planning and Design: Flood Resilient and Sustainable Water Management Using the Example of Coastal Cities in The Netherlands and Taiwan

Urbanized delta areas worldwide share a growing tendency of exposure to water stress induced by the effects of climate change and anthropogenic factors, threatening the operation of infrastructure systems and future urban development. The important synergistic impacts coexisting with freshwater scarcity are increasing urbanization rates, subsiding soils, saltwater intrusion in aquifers and rivers, coastal erosion, and increased flooding. Innovative design strategies and concepts for the integration of decentralized rainwater management measures can contribute to the integrated and climate resilient planning of urban spaces that are threatened by climate change scenarios that worsen the security of urban infrastructures and the future availability of fresh water. Decentralized rainwater management, including retention, storage, and reuse strategies that are integrated into spatial planning and urban design, can reduce flood risks while simultaneously enhancing freshwater availability. This paper discusses a paradigm shift in urban water management, from centralized to decentralized management (that is, from threats to opportunities), using the example of two case studies. Concepts and strategies for building climate resilient cities, which address flood control, the protection of freshwater resources, and the harmonization of a natural and more sustainable water balance, are presented for Almere (Rhine Schelde Delta, The Netherlands) and Hsingchu (Dotzpu Delta, Taiwan).

Tackling challenges in infrastructure operation and control: cross-sectoral learning for process and infrastructure engineers

The need for improving the operation and control of infrastructure systems has created a demand for optimisation and control methods that are applicable in the area of complex networked systems, which are operated by a multitude of actors in a setting of decentralised decision making. Because of the analogy between production systems and infrastructures, Process Systems Engineering (PSE) approaches for optimisation and control can be applied to infrastructure system operations. This paper explores the applicability of the techniques often used by the PSE community, i.e., multilevel optimisation and multiagent Model Predictive Control (MPC) in infrastructure system operation, and stresses their importance for capacity and system management in the energy and transport sectors.

Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks.

Reliable structural health monitoring (SHM) including nondestructiveevaluation (NDE) is essential for safe operation of infrastructure systems. Effectivemonitoring of the rock components of civil infrastructures such as tunnels and cavernsremains challenging. The feasibility of employing smart optical fibre sensor (OFS) andpiezoelectric impedance sensor made up of lead zirconate titanate (PZT) forcomprehensive health monitoring of rocks, covering load history monitoring/retrieval aswell as damage assessment is presented in this paper. The rock specimens are subjected tocyclic loading and their conditions are continuously monitored using OFS and PZTsensors. OFS based multiplexed fibre Bragg grating (FBG) sensors are surface bonded onthe rock specimens. Their strain sensing performance is compared with the conventionalelectric strain gauges (ESGs). In addition, PZT patches are also bonded on the specimensto study the damage pattern during different loading cycles. Unlike the FBGs or ESGs,PZT patches are used as bi-functional sensors and actuators, enabling them to be efficientdetectors of incipient damages using the principle of electromechanical impedance. Theexperimental study demonstrated superior performance of these smart FBG and PZTimpedance sensors. This work is expected to be useful for SHM based NDE application ofrock structures such as caverns and tunnels.

Agent-based control of distributed electricity generation with micro combined heat and power—Cross-sectoral learning for process and infrastructure engineers

For the distributed control of an electricity infrastructure incorporating clusters of residential combined heat and power units (micro-CHP or μCHP) a multi-agent system approach is considered. The network formed by households generating electricity with μCHP units and the facilitating energy supplier can be regarded as an electricity production system, analogous to a (flexible) manufacturing system. Next, the system boundary is extended by allowing the trade of electricity between networks of households and their supplier. A methodology for designing an agent-based system for manufacturing control is applied to both cases, resulting in a conceptual design for a control system for the energy infrastructure. Because of the analogy between production systems and infrastructures process systems engineering (PSE) approaches for optimisation and control can be applied to infrastructure system operations. At the same time we believe research on socio-technical infrastructure systems will be a valuable contribution to PSE management strategies.