97,012 research outputs found

    Knowledge-based support in Non-Destructive Testing for health monitoring of aircraft structures

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    Maintenance manuals include general methods and procedures for industrial maintenance and they contain information about principles of maintenance methods. Particularly, Non-Destructive Testing (NDT) methods are important for the detection of aeronautical defects and they can be used for various kinds of material and in different environments. Conventional non-destructive evaluation inspections are done at periodic maintenance checks. Usually, the list of tools used in a maintenance program is simply located in the introduction of manuals, without any precision as regards to their characteristics, except for a short description of the manufacturer and tasks in which they are employed. Improving the identification concepts of the maintenance tools is needed to manage the set of equipments and establish a system of equivalence: it is necessary to have a consistent maintenance conceptualization, flexible enough to fit all current equipment, but also all those likely to be added/used in the future. Our contribution is related to the formal specification of the system of functional equivalences that can facilitate the maintenance activities with means to determine whether a tool can be substituted for another by observing their key parameters in the identified characteristics. Reasoning mechanisms of conceptual graphs constitute the baseline elements to measure the fit or unfit between an equipment model and a maintenance activity model. Graph operations are used for processing answers to a query and this graph-based approach to the search method is in-line with the logical view of information retrieval. The methodology described supports knowledge formalization and capitalization of experienced NDT practitioners. As a result, it enables the selection of a NDT technique and outlines its capabilities with acceptable alternatives

    Communication framework to support more effective onsite construction monitoring

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    The UK construction industry has recently witnessed an increasing demand for cost-reduction strategies due to the strict government regulations on BIM implementation. This adoption will certainly lead to a continuous work improvement, better project delivery and communication. Although the UK government has set a target of 15–20% saving on the costs of capital projects by the full implementation of BIM level 2 in 2016, this figure is unlikely to be met since the majority of construction companies are still spending approximately £20 billion per year on rebuilding and repairing the construction defects caused by miscommunication. This research addresses the problem of communication using traditional methods (i.e. communication through paper-based documents and drawings) and its impact during the construction phase in relation to clash detection. Next, we will present a communication framework using advanced visualisation technique such as augmen ted reality (AR) combined with a BIM model with an easy access to the IFC f ile on site for a compliance checking between the BIM model and the actual co nstruction site. Subsequently, site inspection can be performed more efficiently, and with more reliability. Furthermore, early warning on future occu rring clashes can be given. To reach our objectives, the research has been designed using real case scenario, following two phases of implementation. The first phase include the communication study and consists of determining users requiring a ssistance with regard to site monitoring and inspection, whereas the second, built on the results of the first phase to specify and implement the mobile AR syste

    Stakeholders’ views on improving the organic certification system: Results from an EU level workshop

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    The FP7 CERTCOST project has the overall objective to give recommendations to the public authorities and private actors in the whole organic certification chain on how to improve the organic food certification systems in terms of efficiency, transparency and cost effectiveness. According to the project description (the Description of Work, or DoW) this will be done based on a scientific economic in depth analysis of the certification systems from the farmer to the consumer in 5 EU countries (the Czech Republic, Denmark, Germany, Italy and the United Kingdom), plus Switzerland and the candidate country, Turkey. To safeguard that the CERTCOST objectives, work plan and methodology is in line with the expectations of key stakeholders from all levels of the certification chain the DoW foresaw a Stakeholder workshop to be organised in the beginning of the project. The current report documents the main points of the discussions and recommendation given by the stakeholders at this CERTCOST Stakeholder workshop, which took place on November, 13-15, 2008 in Izmir, Turkey, 2.5 months after the project had started. A total of 20 stakeholders were invited, of whom 16 could participate in the workshop. The participant profile included both users and providers of the certification system at different levels such as representatives of farmers’ organizations certification/control bodies, government authorities, EU Commission, processors/ traders, private experts/consultants. Together with the representatives of the partner institutions in the CERTCOST project, the total number of workshop participants was 35 representing 12 European countries. Given the diverse backgrounds of the workshop participants, a working group approach (World CafĂ© approach) was applied in order to give the participants the opportunity to reflect their experiences and ideas on the implementation of the project in a synergetic, comfortable and free environment. After a brief presentation of the project, outlining the tasks of the work packages and describing the proposed links between the project and the stakeholders by the project coordinator, the stakeholders were divided into four groups according to their level in the organic certification chain, as farmers, processors/traders, certification bodies and consumers. Two working group sessions were carried out around the questions provided to the stakeholders before the workshop through electronic mails. The questions had been compiled based on input from the managers of the four work packages which were relevant to the workshop discussion. After the first working group session, a plenary discussion session for clustering of the output given by the working groups, their validation and assessment was carried out. In the second session of the working groups, it was rather aimed to harmonize the understanding between the diversified opinions mentioned in Session 1. The working group approach concluded in a final plenary discussion. On the second day, the CERTCOST work package managers presented how the discussions, comments and inputs of the working group sessions could impact on their working plans. In the final session the stakeholders were addressed directly for providing further ideas both on the project and on future collaboration options. The workshop was strongly focused on the identification of key characteristics of cost factors along the supply chain in relation to their impact on the quality of the given service. However a broad range of related subjects were discussed. The Stakeholder workshop put forward that, the ‘cost’ was among the most important topics relating to the certification system performance. The focus of the project aiming at cost effectiveness and not cost minimization was confirmed by the stakeholders. All of the stakeholders present in the workshop demonstrated elevated levels of interest on several outputs of the project. The workshop revealed very positive expectations among the stakeholders towards the risk based approach to be followed in the CERTCOST project. The detailed picture of the organic certification sector obtained through the workshop will constitute an important input to the CERTCOST project and the workshop is considered to be a successful first step in the project-stakeholder interaction. The Stakeholder workshop provided important insight into the many discussion subjects of the organic certification systems in the EU and worldwide, among others the following should be mentioned. Farmers expect to have, clear rules, fair implementation, and high skilled guidance in the inspection and certification process, and underline the need for training of farmers and certifiers and for better communication between all parties in the certification chain. Processors point out the need for a good relationship with the inspectors and certifiers as well as the fact that there existed different schemes in different countries regarding the inspection process and the related cost structure. They also highlighted the difficulty of managing the relations with increasing number of different standards and different certification bodies. It is agreed that consumers expect something they can trust and they can easily recognize, a label, a logo, a certifier, a brand, a farmer or the word ‘organic’; at local, regional, national, or EU-level. It is also concluded that whether, why and how much some consumers might be willing to pay more for particular logos was unknown and was needed to be investigated. Authorities/certification bodies stress that the issue of knowledge and education is extremely important and that there are complex legislations, no common standards, and differences within and between countries. They underline that there are different catalogues in different countries to deal with irregularities which should be harmonized. They emphasize that a clear definition of certification should be made covering its objectives, principles and tools. While on some of the issues there has been a highlighted consensus among the groups, on some others contrasting ideas became evident. Among those subjects of absolute agreement were the importance of and the need for a more clear understanding of the certification system, its components and rules by all the parties involved. Education and elevated levels of necessary skills from farmer to inspector and to consumer; increased transparency and information exchange, well defined relationships between parties were considered to be an indispensable basis for a well functioning and more efficient certification system. The inspection concept came into prominence, with a discussion on policing vs. development approaches. While an efficient and comparable control system was judged to be crucial, promising private governmental formulations were agreed to be based on country conditions. Complexity of the legislation and lack of transparency were the remarkable barriers to a more efficient control system. The EU logo and the new EU Regulation for organic certification were also discussed among stakeholders. It was suggested that the EU logo might have the potential to boost demand in the ‘less developed’ organic markets, but more promotion then currently planned would be needed. It was agreed that most consumers do not look for logos of particular standards but for the word ‘organic’ and/or an organic logo they are familiar with. This might be different for ‘committed’ organic consumers in more mature markets. Overall, it was agreed that ‘trust’ is the most crucial aspect of organic certification regarding the consumer side. The issue of multiple certification and standards appeared to be a factor deserving more attention in the certification world. Harmonization in certification of the same characteristic of a product was deemed necessary. On the other hand, exchange of experiences and cooperation with markets like ‘Fair Trade’ was agreed to be potentially beneficial

    Continuous maintenance and the future – Foundations and technological challenges

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    High value and long life products require continuous maintenance throughout their life cycle to achieve required performance with optimum through-life cost. This paper presents foundations and technologies required to offer the maintenance service. Component and system level degradation science, assessment and modelling along with life cycle ‘big data’ analytics are the two most important knowledge and skill base required for the continuous maintenance. Advanced computing and visualisation technologies will improve efficiency of the maintenance and reduce through-life cost of the product. Future of continuous maintenance within the Industry 4.0 context also identifies the role of IoT, standards and cyber security

    Function allocation theory for creative design

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    Function structure influences on systems architecture (or product architecture). This paper discusses a design method for creative design solutions that focuses on the allocation of functions. It first proposes a theory called “Function Allocation Theory” to allocate a function to an appropriate subsystem or component during the systems decomposition phase. By doing so, the complexity of design solutions can be reduced. The theory is applied to some examples including collaborative robots and robotics maintenance. Finally, the paper illustrates a case study of designing a reaction-free fastening system using this theory

    An ontology framework for developing platform-independent knowledge-based engineering systems in the aerospace industry

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    This paper presents the development of a novel knowledge-based engineering (KBE) framework for implementing platform-independent knowledge-enabled product design systems within the aerospace industry. The aim of the KBE framework is to strengthen the structure, reuse and portability of knowledge consumed within KBE systems in view of supporting the cost-effective and long-term preservation of knowledge within such systems. The proposed KBE framework uses an ontology-based approach for semantic knowledge management and adopts a model-driven architecture style from the software engineering discipline. Its phases are mainly (1) Capture knowledge required for KBE system; (2) Ontology model construct of KBE system; (3) Platform-independent model (PIM) technology selection and implementation and (4) Integration of PIM KBE knowledge with computer-aided design system. A rigorous methodology is employed which is comprised of five qualitative phases namely, requirement analysis for the KBE framework, identifying software and ontological engineering elements, integration of both elements, proof of concept prototype demonstrator and finally experts validation. A case study investigating four primitive three-dimensional geometry shapes is used to quantify the applicability of the KBE framework in the aerospace industry. Additionally, experts within the aerospace and software engineering sector validated the strengths/benefits and limitations of the KBE framework. The major benefits of the developed approach are in the reduction of man-hours required for developing KBE systems within the aerospace industry and the maintainability and abstraction of the knowledge required for developing KBE systems. This approach strengthens knowledge reuse and eliminates platform-specific approaches to developing KBE systems ensuring the preservation of KBE knowledge for the long term

    Hybridization of Bayesian networks and belief functions to assess risk. Application to aircraft deconstruction

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    This paper aims to present a study on knowledge management for the disassembly of end-of-life aircraft. We propose a model using Bayesian networks to assess risk and present three approaches to integrate the belief functions standing for the representation of fuzzy and uncertain knowledge
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