In recent years, a dramatic increase in the study of infrastructure has occurred in the social sciences and humanities, following upon foundational work in the physical sciences, architecture, ...planning, information science, and engineering. This article, authored by a multidisciplinary group of scholars, probes the generative potential of infrastructure at this historical juncture. Accounting for the conceptual and material capacities of infrastructure, the article argues for the importance of paradox in understanding infrastructure. Thematically the article is organized around three key points that speak to the study of infrastructure: ruin, retrofit, and risk. The first paradox of infrastructure, ruin, suggests that even as infrastructure is generative, it degenerates. A second paradox is found in retrofit, an apparent ontological oxymoron that attempts to bridge temporality from the present to the future and yet ultimately reveals that infrastructural solidity, in material and symbolic terms, is more apparent than actual. Finally, a third paradox of infrastructure, risk, demonstrates that while a key purpose of infrastructure is to mitigate risk, it also involves new risks as it comes to fruition. The article concludes with a series of suggestions and provocations to view the study of infrastructure in more contingent and paradoxical forms.
Green infrastructure (GI) revitalizes vegetation and soil, restores hydro-ecological processes destroyed by traditional urbanization, and naturally manages stormwater on-site, offering numerous ...sustainability benefits. However, despite being sustainable and despite being the object of unrelenting expert advocacy for more than two decades, GI implementation remains slow. On the other hand, the practice of traditional gray infrastructure, which is known to have significant adverse impacts on the environment, is still ubiquitous in urban areas throughout the world. This relationship between knowledge and practice seems unaccountable, which has not yet received adequate attention from academia, policy makers, or research communities. We deal with this problem in this paper. The specific objective of the paper is to explore the barriers to GI, and suggest policies that can both overcome these barriers and expedite implementation. By surveying the status of implementation in 10 US cities and assessing the relevant city, state and federal policies, we identified 29 barriers and grouped them into 5 categories. The findings show that most of the barriers stem from cognitive limitations and socio-institutional arrangements. Accordingly, we suggest 33 policies, also grouped into 5 categories, which span from conducting public education and awareness programs to changing policies and governance structures.
•Green infrastructure manages urban stormwater on-site and offers numerous sustainability benefits.•Unfortunately, the pace of implementation of the technology is frustratingly slow.•We explore the barriers to implementation of the technology.•We suggest policies that can both overcome the barriers and expedite implementation.
Summary
The increasing volume of data being produced, curated, and made available by research infrastructures in the environmental science domain require services that are able to optimize the ...delivery and staging of data for researchers and other users of scientific data. Specialized data services for managing data life cycle, for creating and delivering data products, and for customized data processing and analysis all play a crucial role in how these research infrastructures serve their communities, and many of these activities are time‐critical—needing to be carried out frequently within specific time windows. We describe our experiences identifying the time‐critical requirements of environmental scientists making use of computational research support environments. We present a microservice‐based infrastructure optimization suite, the Dynamic Real‐Time Infrastructure Planner, used for constructing virtual infrastructures for research applications on demand. We provide a case study whereby our suite is used to optimize runtime service quality for a data subscription service provided by the Euro‐Argo using EGI Federated Cloud and EUDAT's B2SAFE services, and to consider how such a case study relates to other application scenarios.
Drawing on the large-scale public investment in roads undertaken in Turkey during the 2000s, this paper contributes to our understanding of how internal transportation infrastructure affects regional ...access to international markets. Using data on international trade of Turkish provinces and the change in the capacity of the roads connecting them to the international gateways of the country, we estimate the distance elasticity of trade associated with roads of varying capacity. Three key results emerge. First, the cost of an average shipment over a high-capacity expressway is about 70% lower than it is over single-lane roads. Second, the present value of a 10-year stream of trade flows generated by a one-dollar investment in road infrastructure ranges between $0.7 and $2. Third, the reduction in transportation costs is greater the more transportation-sensitive an industry is. To the extent that efficient logistics enable countries to take part in global supply chains and exploit their comparative advantages, our findings have important developmental implications.
•Internal transportation infrastructure matters for access to international markets.•Turkey undertook a major upgrade to its intercity road network during the 2000s.•Using data from this episode, we estimate the reduction in transport costs.
The Suez Canal (SC) is an important infrastructure for the maritime shippingon a global scale. The costs and distances of voyages can be greatly reduced, particularlyfor vessels navigating between ...Asia and Europe. This paper first focuses on the share ofthe SC transit by region pair which the cargo originates from and is destined to, in order torecognize how the SC is competing with other routes (such as a route via the Panama Canalor the Cape of Good Hope) in the container shipping market on a global scale. The sharesestimated in different years (2010 and 2013) are compared to examine the recent change inthe competitive environment of the SC. In the second part of the paper, the model to describe the shares of each route is developed.An aggregated logit model, which is one of the most major stochastic discrete choicemodels, is adopted to describe. The model focuses on the supply side of container shippingmarket, namely, monetary shipping cost and time. It is confirmed that the developed modelincluding estimated unknown parameters agrees with the actual shares of each route well.By utilizing the developed model, some future simulations such as reflecting the PanamaCanal expansion are examined.
From the Editor Little, Richard G
Public works management & policy,
07/2016, Letnik:
21, Številka:
3
Journal Article
Recenzirano
In this issue of Public Works Management & Policy, we focus on the perspectives of many different players who comprise the infrastructure community and the delivery of services that these systems ...provide.
•Integrated modelling of asset damage, repair and network flows.•Optimisation of dynamic repair resource allocation and flow assignment.•Interdependency: failure propagation, serial/parallel ...sub-systems, resource inputs.•Case study on London's metro and electric power networks.
Critical infrastructure systems are becoming increasingly interdependent, which can exacerbate the impacts of disruptive events through cascading failures, hindered asset repairs and network congestion. Current resilience assessment methods fall short of fully capturing such interdependency effects as they tend to model asset reliability and network flows separately and often rely on static flow assignment methods. In this paper, we develop an integrated, dynamic modelling and simulation framework that combines network and asset representations of infrastructure systems and models the optimal response to disruptions using a rolling planning horizon. The framework considers dependencies pertaining to failure propagation, system-of-systems architecture and resources required for operating and repairing assets. Stochastic asset failure is captured by a scenario tree generation algorithm whereas the redistribution of network flows and the optimal deployment of repair resources are modelled using a minimum cost flow approach. A case study on London's metro and electric power networks shows how the proposed methodology can be used to assess the resilience of city-scale infrastructure systems to a local flooding incident and estimate the value of the resilience loss triangle for different levels of hazard exposure and repair capabilities.
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There is an urgent need to decarbonise transport- this includes the infrastructure. Railways have a key role to play in decarbonising transport because they are very energy-efficient, but the ...infrastructure and its upkeep are costly in money and carbon. Infrastructure maintenance requirements are likely to increase if the number, speed and weight of trains increase. This makes reducing the maintenance needs of the railways even more urgent. Traditionally, ballast has been considered to be life-expired after 10-50 tamps - typically about 30 years of service on moderate to busy lines. Overall maintenance needs could be reduced by reducing the need to maintain and then to replace ballast. This can be achieved by better understanding the performance of used ballast - cleaned and recovered. This thesis presents quantitative research into the relative shape properties of fresh and used ballast and relates these quantitative measures of shape to tested performance. Methods of evaluating surface roughness for railway ballast are proposed. Shape characterisation showed no significant difference in form between fresh and used ballast, a slight reduction in angularity in used ballast, and a significant reduction in roughness in used ballast. Scaled used ballast was synthesised for triaxial shear testing in the laboratory by abrading scaled fresh ballast in the Micro-Deval apparatus to a target shape equal to that of the used ballast. Effects of surface roughness and grain attrition due to loading on frictional properties of ballast were also investigated. Fresh and used ballast showed similar contact frictional properties. The study found that although the roughness of used ballast was smaller than that of fresh, both were similar in shape and showed similar strength properties. Ballast developed a stable structure over a few hundred thousand loading cycles. The resilient modulus increased by up to 60% with an increase in load cycles until about 200000 cycles; after this point, there was no significant increment. Cyclic loading improved the ballast strength by up to 15%. The study found that life-expired ballast of granitic origin could be reused.
Investment in infrastructure is essential for promoting economic growth, and while countries in Asia have enjoyed higher rates of gross domestic product growth in recent years, the region remains ...severely deficient in the scale and quality of sustainable infrastructure. Moreover, population growth and climate change continue to put increasing pressure on the need for strategic and farsighted development, calling for policy makers to reevaluate infrastructure governance to ensure sustainable economic growth. Currently, in developing Asia, most investment in infrastructure comes from the public sector. However, with growing fiscal deficits and other budgetary constraints, it is essential to develop alternative sources of investment for infrastructure projects. This presents opportunities to tap into the private sector, which can play an instrumental role in minimizing the funding gap through the development of stronger, more transparent public–private partnerships (PPPs) and incentivizing sustainable infrastructure investment. This book provides a scholarly discussion on the importance of PPPs and approaches to unlock private participation in infrastructure investment based on lessons from across Asia. Among the proposed schemes are government tax incentives, development-based land value capture strategy under PPP land pooling, Viability Gap Funds, Project Development Facilities, and other guarantees. The book aims to assess the impacts and future of sustainable infrastructure investments and examines the role of governments in mobilizing financial resources and new models for unlocking private investment in sustainable infrastructure. This book consists of fifteen original chapters on the experiences of the Central Asia Regional Economic Cooperation (CAREC) and a few other cases for promoting private investment in sustainable infrastructure. The fact that not much has been published previously on this theme makes this book a welcome and timely addition to the much needed knowledge on this subject. ‘The Open Access version of this book, available at www.taylor fran cis.com, has been made available under a Creative Commons Attribution- Non- Commercial- No Derivatives 4.0 license.’
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