Towards a service-oriented e-infrastructure for multidisciplinary environmental research

Research e-infrastructures are considered to have generic and thematic parts. The generic part provids high-speed networks, grid (large-scale distributed computing) and database systems (digital repositories and data transfer systems) applicable to all research commnities irrespective of discipline. Thematic parts are specific deployments of e-infrastructures to support diverse virtual research communities. The needs of a virtual community of multidisciplinary envronmental researchers are yet to be investigated. We envisage and argue for an e-infrastructure that will enable environmental researchers to develop environmental models and software entirely out of existing components through loose coupling of diverse digital resources based on the service-oriented achitecture. We discuss four specific aspects for consideration for a future e-infrastructure: 1) provision of digital resources (data, models & tools) as web services, 2) dealing with stateless and non-transactional nature of web services using workflow management systems, 3) enabling web servce discovery, composition and orchestration through semantic registries, and 4) creating synergy with existing grid infrastructures

Harmonizing Software Standards with a Semantic Model

The application of standards in the software development process supports interoperability between systems. Maintenance of standards must be guaranteed on the organisational and technical level. The use of semantic technologies can contribute to the standard maintenance process by providing a harmonizing bridge between standards of different knowledge domains and languages and by providing a single point of administration for standard domain concepts. This paper describes a case study of the creation of a semantic layer between software standards for water management systems in The Netherland

Memory-based immigrants for ant colony optimization in changing environments

Copyright @ 2011 SpringerAnt colony optimization (ACO) algorithms have proved that they can adapt to dynamic optimization problems (DOPs) when they are enhanced to maintain diversity. DOPs are important due to their similarities to many real-world applications. Several approaches have been integrated with ACO to improve their performance in DOPs, where memory-based approaches and immigrants schemes have shown good results on different variations of the dynamic travelling salesman problem (DTSP). In this paper, we consider a novel variation of DTSP where traffic jams occur in a cyclic pattern. This means that old environments will re-appear in the future. A hybrid method that combines memory and immigrants schemes is proposed into ACO to address this kind of DTSPs. The memory-based approach is useful to directly move the population to promising areas in the new environment by using solutions stored in the memory. The immigrants scheme is useful to maintain the diversity within the population. The experimental results based on different test cases of the DTSP show that the memory based immigrants scheme enhances the performance of ACO in cyclic dynamic environments.This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/2

Trade-offs in the design of cross-disciplinary software systems

As researchers we are often faced with the difficult and demanding task of preparing models, and their computer implementations, for decision making, or, more recently, for integrated assessment. Such assessment often involves large scale problems, where the decisions to be made can deeply affect the environment, the social context and the economic background of regions and even nations. Yet, we face the grim reality that a model is a focused representation of the world, and it is always a result of several compromises in terms of details and structure, leading to trade-offs in terms of complexity, flexibility and performance. This trade-off becomes an essential design property. We often wish our models to be as simple as possible, balancing transparency, understandability and level of detail. Now, we are involved in the SEAMLESS project, an EU FP6 Integrated Project, aims at generating an integrated framework of computer models. This framework can be used for assessment of how future alternative agricultural and environmental polices affect sustainable development in Europe. Thus, we are designing a cross disciplinary software system to deal with different simulation domains. In this, we need to take care of many differences between the different modeling societies. We decided to apply an architecture centric development method and evaluated this with stakeholders based on a so-called Architecture Trade-off Analysis method. When prioritizing the requirements we used a cost-benefit analysis as a weighting factor for deciding what to do first. Requirements were grouped in user-roles, that appeal to differences in user-interface options. The resulting software architecture identified the necessity to identify two major blocks: the modeling environment, to be used by a number of user roles, mostly modelers and coders, and the processing environment, which is oriented towards the needs of those user roles more focused on system analysis, rather than design and implementation. Another key factor of our architecture is the knowledge base, which provides a common repository for all knowledge, data, model sources which are shared by the two environments. When moving on from architecture to design and implementation, we tried to steer clear of the risk of inventing another modelling framework, and therefore in our prototype we use different existing frameworks for different tasks in the overall design. This means that we discussed the view that 'one tool fixes everything', and we chose to rely on specific frameworks for specific needs. We chose a modelling framework with a track record in crop modeling, to target our biophysical modeling needs, and we selected a de facto standard framework for economic modeling to solve agri-economic modelling problems. All of this comes at a price, that is the extra effort required to integrate different frameworks. We chose therefore to develop an evolution of the OpenMI integration framework to target this issue. In this article we describe all the risks we have identified as associated to our architecture centric approach and how we dealt with them. This article describes the design of the modeling framework for SEAMLESS. A first prototype is ready in January 2006

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Taha Toros Arşivi, Dosya No: 112-Lokantalarİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033