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1.
Computational simulations and thus scientific computing is the third pillar alongside theory and experiment in todays science. The term e-science evolved as a new research field that focuses on collaboration in key areas of science using next generation computing infrastructures (i.e. co-called e-science infrastructures) to extend the potential of scientific computing. During the past years, significant international and broader interdisciplinary research is increasingly carried out by global collaborations that often share a single e-science infrastructure. More recently, increasing complexity of e-science applications that embrace multiple physical models (i.e. multi-physics) and consider a larger range of scales (i.e. multi-scale) is creating a steadily growing demand for world-wide interoperable infrastructures that allow for new innovative types of e-science by jointly using different kinds of e-science infrastructures. But interoperable infrastructures are still not seamlessly provided today and we argue that this is due to the absence of a realistically implementable infrastructure reference model. Therefore, the fundamental goal of this paper is to provide insights into our proposed infrastructure reference model that represents a trimmed down version of ogsa in terms of functionality and complexity, while on the other hand being more specific and thus easier to implement. The proposed reference model is underpinned with experiences gained from e-science applications that achieve research advances by using interoperable e-science infrastructures.  相似文献   

2.
This article presents a new rule-based decision support system for critical infrastructure management based on the interdependencies among critical infrastructures. Unlike the conventional flood front prediction model, the new failure front prediction model consists of both physical parameters and interdependencies among infrastructures, which is represented by a multi-level complex network. This study employs advanced computation methods to build tools for better understanding emergent behavior of water security infrastructure systems for use in developing superior preparedness and response strategies. This study highlights the important role played by the interdependencies among the infrastructures in failure front prediction.  相似文献   

3.
In implantology, when financial or biological feasibility limitations appear, it is necessary to use prostheses with geometries that deviate from the conventional, with a pontic in the absence of an intermediate implant. The aim of this study was analyze and understand the general differences in the stresses generated in implants, components and infrastructures according to the configuration of the prosthesis over three or two implants. Thus, this paper analyzes the von Mises equivalent stresses (VMES) of ductile materials on their external surfaces. The experimental groups: Regular Splinted Conventional Group (RCG), which had conventional infrastructures on 3 regular-length Morse taper implants (4x11?mm); Regular Splinted Pontic Group (RPG), which had infrastructures with intermediate pontics on 2 regular-length Morse taper implants (4x11?mm). The simulations of the groups were created with Ansys Workbench 10.0 software. The results revealed that the RPG presented greater areas of possible fragility due to higher stress concentrations, for example, in the cervical area of the union between the implant and component the top platform of the abutment, as well as greater coverage of the stress by the cervical implant threads. The RPG infrastructure was also more affected by stresses in the connection areas between the prostheses and on the occlusal surface. There is an advantage to using prostheses supported by a greater number of implants (RCG) because this decreases the stress in the analyzed structures and consequently improves stress dissipation to the supporting bone, which would preserve the system.  相似文献   

4.
ABSTRACT

“Critical infrastructures” are exceedingly complex and highly interconnected. In order to gain a full understanding and comprehensive awareness of the risks associated with critical infrastructures it becomes essential to consider in a coherent way all the aspects that may cause a failure of such systems. That is, there is a need for a systemic approach to interdependencies among critical infrastructures. The article presents the application of a systemic safety management system (SSMS) model to interdependency modeling for the case of the Mexico City Metro transport network. The model has highlighted that interdependencies occur vertically and horizontally. Horizontal interdependency occurs at every level of recursion and can be: operational, managerial, and environmental. Vertical interdependency, on the other hand, occurs between two levels of recursion only. The SSMS model has shown the potential to be used to model interdependencies among critical infrastructures. It is hoped that the approach presented may help to gain a better understanding of critical infrastructure interdependency.  相似文献   

5.
Climate change is expected to impact both the operational and structural performance of infrastructures such as roads, bridges, and buildings. However, most past life cycle assessment (LCA) studies do not consider how the operational/structural performance of infrastructure will be affected by a changing climate. The goal of this research was to develop a framework for integrating climate change impacts into LCA of infrastructure systems. To illustrate this framework, a flexible pavement case study was considered where life‐cycle environmental impacts were compared across a climate change scenario and several time horizons. The Mechanistic‐Empirical Pavement Design Guide (MEPDG) was utilized to capture the structural performance of each pavement performance scenario and performance distresses were used as inputs into a pavement LCA model that considered construction and maintenance/rehabilitation materials and activities, change in relative surface albedo, and impacts due to traffic. The results from the case study suggest that climate change will likely call for adaptive design requirements in the latter half of this century but in the near‐to‐mid term, the international roughness index (IRI) and total rutting degradation profile was very close to the historical climate run. While the inclusion of mechanistic performance models with climate change data as input introduces new uncertainties to infrastructure‐based LCA, sensitivity analyses runs were performed to better understand a comprehensive range of result outcomes. Through further infrastructure cases the framework could be streamlined to better suit specific infrastructures where only the infrastructure components with the greatest sensitivity to climate change are explicitly modeled using mechanistic‐empirical modeling routines.  相似文献   

6.
Infrastructural systems have emerged as productive ethnographic sites for analysing political subjectivities and rationalities. Through the case of shared electricity and prepaid meters in the compound housing system of Accra, Ghana, I suggest that infrastructures’ political potential lies in their imaginative and hermeneutic abilities to foster desires for dignity, sustain well-being, and question moral ideals of collective life. In contrast to recent anthropological work that has emphasized the material basis of infrastructures as ‘techno-political’ devices materializing certain logics of rule and governance, I reclaim a poetics of sociality whereby infrastructures mobilize a politics of (unwanted) collective life. Through the ‘electricity stories’ circulated by tenants, I chart how the moral economy of infrastructure in a context of collective precarity redistributes marginalization and freedom in ways that always exceed political rationales of energy reforms and policies.  相似文献   

7.
Li  Liqing  Li  Shun  Ma  Xugao  Yan  Yuqing 《Ecosystems》2023,26(4):815-825
Ecosystems - Green infrastructures (GIs) are environmental designs mainly used to treat urban stormwater runoff pollution. The influences of green infrastructure designs are associated with the...  相似文献   

8.
Functioning of developed (definitive) social systems in ants is impossible without formation of a complex of interrelated supporting structures and methods, regulating forager activity in the territory, in other words, without formation of the infrastructure. In dependence of the territorial strategy, different infrastructures are formed; each of them possesses specific features. Four types of infrastructure are described. The tunnel-based infrastructure is characterized by the use of tunnels (Solenopsis invicta is a typical representative). The road-based infrastructure is characterized by the use of constant roads (Formica s. str.). The nomadic infrastructure is characterized by a constant change of family habitats (army ants). The orbital infrastructure is characterized by the multivariant access of foragers to sites of the secondary subdivision of the territory (Formica exsecta). The types of infrastructure are compared according to the following parameters:cost of raising and maintaining, dynamics of elements, the degree of forager protection, level of territory exploitation, and capacity. An assumption on the influence of the type of infrastructure on ant behavior is made.  相似文献   

9.
10.
The large choice of Distributed Computing Infrastructures (DCIs) available allows users to select and combine their preferred architectures amongst Clusters, Grids, Clouds, Desktop Grids and more. In these hybrid DCIs, elasticity is emerging as a key property. In elastic infrastructures, resources available to execute application continuously vary, either because of application requirements or because of constraints on the infrastructure, such as node volatility. In the former case, there is no guarantee that the computing resources will remain available during the entire execution of an application. In this paper, we show that Bag-of-Tasks (BoT) execution on these “Best-Effort” infrastructures suffer from a drop of the task completion rate at the end of the execution. The SpeQuloS service presented in this paper improves the Quality of Service (QoS) of BoT applications executed on hybrid and elastic infrastructures. SpeQuloS monitors the execution of the BoT, and dynamically supplies fast and reliable Cloud resources when the critical part of the BoT is executed. SpeQuloS offers several features to hybrid DCIs users, such as estimating completion time and execution speedup. Performance evaluation shows that BoT executions can be accelerated by a factor 2, while offloading less than 2.5 % of the workload to the Cloud. We report on several scenarios where SpeQuloS is deployed on hybrid infrastructures featuring a large variety of infrastructures combinations. In the context of the European Desktop Grid Initiative (EDGI), SpeQuloS is operated to improve QoS of Desktop Grids using resources from private Clouds. We present a use case where SpeQuloS uses both EC2 regular and spot instances to decrease the cost of computation while preserving a similar QoS level. Finally, in the last scenario SpeQuloS allows to optimize Grid5000 resources utilization.  相似文献   

11.
When an alternative fuel is introduced, the infrastructure through which that fuel is made available to the market is often underdeveloped. Transportation service providers relying on such infrastructures are unlikely to adopt alternative fuel vehicles as it may impose long detours for refueling. In this paper, we design and apply a new solution approach to derive minimum infrastructure requirements, in terms of the number of alternative fuel stations. The effectiveness of our approach is demonstrated by applying it to the case of introducing liquefied natural gas (LNG) as a transportation fuel in The Netherlands. From this case, we learn that, depending on the driving range of the LNG trucks and the size of area on which those trucks operate, a minimum of 5–12 LNG fuel stations is necessary to render LNG trucks economically and environmentally beneficial.  相似文献   

12.
One of the most serious bottlenecks in the scientific workflows of biodiversity sciences is the need to integrate data from different sources, software applications, and services for analysis, visualisation and publication. For more than a quarter of a century the TDWG Biodiversity Information Standards organisation has a central role in defining and promoting data standards and protocols supporting interoperability between disparate and locally distributed systems.Although often not sufficiently recognized, TDWG standards are the foundation of many popular Biodiversity Informatics applications and infrastructures ranging from small desktop software solutions to large scale international data networks. However, individual scientists and groups of collaborating scientist have difficulties in fully exploiting the potential of standards that are often notoriously complex, lack non-technical documentations, and use different representations and underlying technologies. In the last few years, a series of initiatives such as Scratchpads, the EDIT Platform for Cybertaxonomy, and biowikifarm have started to implement and set up virtual work platforms for biodiversity sciences which shield their users from the complexity of the underlying standards. Apart from being practical work-horses for numerous working processes related to biodiversity sciences, they can be seen as information brokers mediating information between multiple data standards and protocols.The ViBRANT project will further strengthen the flexibility and power of virtual biodiversity working platforms by building software interfaces between them, thus facilitating essential information flows needed for comprehensive data exchange, data indexing, web-publication, and versioning. This work will make an important contribution to the shaping of an international, interoperable, and user-oriented biodiversity information infrastructure.  相似文献   

13.
This paper describes a technique that allows an MPI code to be encapsulated into a component. Our technique is based on an extension to the Common Object Request Broker Architecture (CORBA) from the OMG (Object Management Group). The proposed extensions do not modify the CORBA core infrastructure (the Object Request Broker) so that it can fully coexist with existing CORBA applications. An MPI code is seen as a new kind of CORBA object that hides most of the cumbersome problems when dealing with parallelism. Such a technique can be used to connect MPI codes to existing CORBA software infrastructures which are now being developed in the framework of several research and development projects such as JACO3*, JULIUS** or TENT*** from DLR. To illustrate the concept of parallel CORBA object, we present a virtual reality application that is made of the coupling of a light simulation application (radiosity) and a visualisation tool using VRML and Java.  相似文献   

14.
As business imperatives change and new high-capability information technologies (IT) appear, organizations recognize the need to remain at the forefront of change by reengineering their business processes and implementing enabling responsive IT infrastructures. However, experience in this context indicates a lack of comprehension of essential elements and their mutual relationships that can contribute to the success of business-process change-implementation efforts. This article proposes a framework for managing IT for effective business-process redesign (BPR) implementation. After establishing BPR principles, components, and the relationship of BPR to some organizational and technological approaches, it presents the role and benefits of IT in BPR. The article then discusses in detail the core elements of the framework. Its theme is that an IT infrastructure that covers issues of BPR strategy development, IT strategic alignment, IT infrastructure development, IT sourcing, legacy systems reengineering, IS integration, and IS function competence is essential and critical for effective implementation.  相似文献   

15.
Functional landscapes in cities: a systems approach   总被引:1,自引:0,他引:1  
Human enterprise and endeavour increasingly influence global processes of change, from the planetary scale down to the very local. Cities are hubs of human activity, and as the places where the majority of the world’s population live we must, when looking into an uncertain future, consider how we think about urban design. Cities are densely inhabited, lived-in landscapes where human presence and perceptions are deeply enmeshed with biophysical and built infrastructures. As such, they present complex mosaics of different habitats and competing uses, ever changing in response to human and physical drivers. If designed properly, green infrastructure can contribute many important functions to a city. Efforts to strategically make use of green infrastructure can benefit considerably from a systems perspective where linkages and cross-boundary dynamics are at the very least as important as individual components. Design, planning and governance of requirements for green infrastructure also extend far beyond biophysical elements and components. Recognition of interconnections between individual green spaces, green infrastructure and the built environment, the physical environment and diverse actors, and formal and informal governance arrangements—as outlined in the four design principles in this article—is a first important step towards a more comprehensive and inclusive approach, not least to green infrastructure planning and design.  相似文献   

16.
Transport infrastructure elements are widespread and increasing in size and length in many countries, with the subsequent alteration of landscapes and wildlife communities. Nonetheless, their effects on habitat selection by raptors are still poorly understood. In this paper, we analyzed raptors’ foraging habitat selection in response to conventional roads and high capacity motorways at the landscape scale, and compared their effects with those of other variables, such as habitat structure, food availability, and presence of potential interspecific competitors. We also analyzed whether the raptors’ response towards infrastructure depends on the spatial scale of observation, comparing the attraction or avoidance behavior of the species at the landscape scale with the response of individuals observed in the proximity of the infrastructure. Based on ecological hypotheses for foraging habitat selection, we built generalized linear mixed models, selected the best models according to Akaike Information Criterion and assessed variable importance by Akaike weights. At the community level, the traffic volume was the most relevant variable in the landscape for foraging habitat selection. Abundance, richness, and diversity values reached their maximum at medium traffic volumes and decreased at highest traffic volumes. Individual species showed different degrees of tolerance toward traffic, from higher abundance in areas with high traffic values to avoidance of it. Medium-sized opportunistic raptors increased their abundance near the traffic infrastructures, large scavenger raptors avoided areas with higher traffic values, and other species showed no direct response to traffic but to the presence of prey. Finally, our cross-scale analysis revealed that the effect of transport infrastructures on the behavior of some species might be detectable only at a broad scale. Also, food availability may attract raptor species to risky areas such as motorways.  相似文献   

17.
Strategies for Meeting EU End-of-Life Vehicle Reuse/Recovery Targets   总被引:1,自引:0,他引:1  
Disposal of end-of-life vehicles (ELVs) is a relatively new focus of the European policy community. Technical requirements for car design and minimum reuse and recovery rates for end-of-life vehicles are the subject of a recent European Union directive on ELVs. This directive is expected to induce changes in the infrastructure required for ELV processing, and presents a substantial challenge to maintaining such an infrastructure as economically viable.
This paper assesses current and emerging ELV recycling technologies, in order to provide guidelines for the development of future ELV recycling strategies. Emphasis is given to technologies dedicated to automobile shredder residue (ASR) recovery, as an alternative/complement to more labor-intensive dismantling activities. The ultimate goal is to develop a vision of the type of ASR processing technology that could emerge in the future.
The analysis is based on a model developed to simulate ELV processing infrastructures, and shredding data are taken from full-scale experiments. The results obtained show that ASR mechanical separation and recycling technologies may enable more extensive recycling and contribute to achieving European Union recycling targets, and can thus be considered as far more promising than technologies based on energy recovery.  相似文献   

18.
With more microbiome studies being conducted by African-based research groups, there is an increasing demand for knowledge and skills in the design and analysis of microbiome studies and data. However, high-quality bioinformatics courses are often impeded by differences in computational environments, complicated software stacks, numerous dependencies, and versions of bioinformatics tools along with a lack of local computational infrastructure and expertise. To address this, H3ABioNet developed a 16S rRNA Microbiome Intermediate Bioinformatics Training course, extending its remote classroom model. The course was developed alongside experienced microbiome researchers, bioinformaticians, and systems administrators, who identified key topics to address. Development of containerised workflows has previously been undertaken by H3ABioNet, and Singularity containers were used here to enable the deployment of a standard replicable software stack across different hosting sites. The pilot ran successfully in 2019 across 23 sites registered in 11 African countries, with more than 200 participants formally enrolled and 106 volunteer staff for onsite support. The pulling, running, and testing of the containers, software, and analyses on various clusters were performed prior to the start of the course by hosting classrooms. The containers allowed the replication of analyses and results across all participating classrooms running a cluster and remained available posttraining ensuring analyses could be repeated on real data. Participants thus received the opportunity to analyse their own data, while local staff were trained and supported by experienced experts, increasing local capacity for ongoing research support. This provides a model for delivering topic-specific bioinformatics courses across Africa and other remote/low-resourced regions which overcomes barriers such as inadequate infrastructures, geographical distance, and access to expertise and educational materials.  相似文献   

19.
公路建设的主要生态影响   总被引:8,自引:0,他引:8  
郑海峰  管东生 《生态学杂志》2005,24(12):1520-1524
公路已成为全球景观中一种重要的景观类型,其里程和密度在逐年增加.公路建设项目,尤其是公路网络的形成不仅减少了自然生境的数量,而且严重降低了自然生境的质量.公路建设对生态环境造成的影响主要包括生境损失、生态干扰、公路致死、阻碍作用、廊道效应以及公路网络造成的严重生境破碎化.缓解公路生态影响的措施有避免、消减和补偿3种.  相似文献   

20.
We review technical and sociological issues facing the Life Sciences as they transform into more data-centric disciplines - the "Big New Biology". Three major challenges are: 1) lack of comprehensive standards; 2) lack of incentives for individual scientists to share data; 3) lack of appropriate infrastructure and support. Technological advances with standards, bandwidth, distributed computing, exemplar successes, and a strong presence in the emerging world of Linked Open Data are sufficient to conclude that technical issues will be overcome in the foreseeable future. While motivated to have a shared open infrastructure and data pool, and pressured by funding agencies in move in this direction, the sociological issues determine progress. Major sociological issues include our lack of understanding of the heterogeneous data cultures within Life Sciences, and the impediments to progress include a lack of incentives to build appropriate infrastructures into projects and institutions or to encourage scientists to make data openly available.  相似文献   

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