620 research outputs found
Understanding system innovations : a critical literature review and a conceptual synthesis
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Socio-technical scenarios as a tool for transition policy : an example from the traffic and transport domain
No full textModern societies face huge challenges related to existing socio-technical systems which are difficult to tackle without fundmental change. An example is the agriculture-food system with various unsustainable features like BSE, foot and mouth disease, high nitrous emissions, etc. Another example is watersupply with symptoms like floodings, soil dehydration, water quality problems. Also the transport system faces structural problems like congestion, atmosferic pollution (NOx and particulates), and CO2-emissions. Such problems are deeply rooted in societal structures and institutions and are closely related to societal processes. To solve such problems fundamentally requires transitions or system innovations as is argued in the fourth Dutch National Environmental Policy Plan (VROM 2001).
A transition in this sense denotes a long-term development process in an encompassing system that fulfills a basic societal function like feeding, mobility, energy, communication, etc. A transition implies a drastic change of the technical as well as the societal and cultural diminsions of such a system. This emphasis on coevolution of technical and societal change distinguishes transitions from more incremental processes of innovation which are primarily characterised by technnical development (successive generations of technologies) while the societal embedding of these technologies changes relatively little (cf. Geels in this volume)
Feelings of discontent and the promise of middle range theory for STS: Examples from technology dynamics
No full textThis article critically discusses the state of STS, expressing feelings of discontent regarding four aspects: policy relevance, conceptual language, too much focus on complexity, theoretical styles. Middle range theory is proposed as an alternative, promising avenue. Middle range theories focus on delimited topics, make explicit efforts to combine concepts, and search for abstracted patterns and explanatory mechanisms. The article presents achievements in that direction for technology dynamics, particularly with regard to the role of expectations, niche theory and radical innovation, and the multi-level perspective on sociotechnical transitions
Damage mechanism characterization of ±35° and ±55° FW composite tubes using acoustic emission method
No full textThe focus of this study is to investigate the mechanical properties, of ±35° and ±55° filament wound (FW) composite tubes under axial compression loading using the acoustic emission technique. For this purpose, material failure, crashworthiness characteristics, and the effect of each mechanism on the energy absorption capacity were studied using numerical and experimental approaches. Also, to identify and estimate the contribution percentage of damage mechanisms as well as how the damage grows in the specimens, the analysis of acoustic emission signals recorded during loading was performed. Digital image correlation was additionally used to capture displacement/strain contour maps. Finally, to analyze the effect of the winding pattern in the experimental test, the tubes were simulated using finite element analysis (FEA). For modeling of damage mechanisms, a 3D continuum damage model was used. The results of signal processing showed that by increasing the weaving angle of fibers from ±35° to ±55°, the separation of fibers from the matrix decreases, and the percentage of matrix crushing and fiber failure increases. The assessment of damage percentages showed that the reason for the large drop in force at ±55° compared to ±35° is the increase in matrix crushing. Furthermore, the failure behavior of FW tubes appeared to be dominated by local buckling, and the FEA effectively predicted the linear behavior and maximum load value of the composite tubes.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Ship Hydromechanics and Structure
De dynamiek van sociaaltechnische veranderingen in transport en mobiliteit
No full textAbstract niet beschikbaarThis report is the result of the subproject on Transport & Mobility in the Management of Technology Responses to the Climate Change Challange (Matric) project. The aim of this subproject is to offer recommendations on the improvement of the management of sociotechnical change to climate change needs in the transport and mobility domain. Automobile transport and mobility give rise to problems of local air pollution and are major emitters of greenhouse gases. This report studies how climate protection goals can be pursued in the transport and mobility domain through modulation policies and a change in the mode of governance. First, the report sketches the tour d'horizon of sociotechnical developments in the transport & mobility domain from 1886 onwards. Then, it focuses on various case studies in the car-based transport & mobility domain, studying the dynamics of sociotechnical change. Analysis of the mechanisms of sociotechnical change in the case studies leads to various modes of governance in the transport and mobility domain. The report finally proposes a new role for transport authorities: that of an alignment actor and facilitator of change; and the use of programs for system innovation that offers sustainability benefits. The report states that climate policy has to piggy-back-ride on sustainability issues and it offers suggestions for how to do this. These actions should be pursued as part of a transition programme.SG-NO
Cultural legitimacy and innovation journeys : a new perspective applied to Dutch and British nuclear power
No full textPhotometric study of two detached binaries FW Vel and BB Mon
No full text32nd International Physics Congress of Turkish-Physical-Society (TPS) -- SEP 06-09, 2016 -- Bodrum, TURKEYWe present the first analysis of photometric observations of two detached binary stars, FW Vel and BB Mon. Their V light curves from the All Sky Automated Survey were solved using Monte Carlo Search Method. The final solutions describe these two systems as Algol-like binary stars with detached configurations. The absolute parameters of the components of the systems were also estimated.Turkish Phys So
Multi-level perspective on system innovation: relevance for industrial transformation
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Aircraft hydraulic power system diagnostic, prognostics and health management
No full textThis Individual Research Project (IRP) is the extension research to the group design project (GDP) work which the author has participated in his Msc programme. The GDP objective is to complete the conceptual design of a 200-seat, flying wing civil airliner—FW-11. The next generation aircraft design demands higher reliability, safety and maintainability.
With the development of the vehicle hydraulic system technology, the equipment and systems become more and more complex, their reliability and maintenance become more difficult for designers, manufacturers and customers. To improve the mission reliability and reduce life cycle cost, there is strong demand for the application of health management technology into airframe system design.
In this research, the author introduced diagnostic, prognostic and health management (DPHM) concept into the aircraft hydraulic power system development. As a brand new technology, it is a challenge to apply the DPHM techniques to on-board system. Firstly, an assumed hydraulic power system was designed for FW-11 by the author and used as the case in his IRP research. Then the crucial components and key parameters needed to be monitored were obtained based on Function Hazard Analysis and Failure Modes Effects Analysis of this system. The writer compared a few diagnostic and prognostic methods in detail, and then selected suitable ones for a hydraulic power system. A diagnostic process was applied to the hydraulic power system using a Case-based reasoning (CBR) approach, whilst a hybrid prognostic method was suggested for the system. After that, a diagnostic, prognostic and health management (DPHM) architecture of the hydraulic power system was designed at system level based on the diagnostic and prognostic research. The whole research work provided a general and practical instruction for hydraulic system design by means of DPHM application
The dynamics of transitions in socio-technical systems: a multi-level analysis of the transition pathway from horse-drawn carriages to automobiles (1860-1930)
No full textThis article investigates transitions at the level of societal functions (e.g. transport, communication, housing). Societal functions are fulfilled by socio-technical systems, which consist of a cluster of aligned elements, e.g. artefacts, knowledge, user practices and markets, regulation, cultural meaning, infrastructure, maintenance networks and supply networks. To understand how transitions from one socio-technical system to another come about, the article describes a conceptual multi-level perspective. The perspective is illustrated with a historical case study: the transition from horse-drawn carriages to automobiles in the USA (1860-1930). The case study shows that technological substitution approaches to this transition are too simple, because they neglect the electric tram and bicycle, which acted as important stepping stones. The case study also corrects another mistake, namely that the gasoline car won by chance from steam and electric automobiles. It will be shown that particular niches played a crucial role in this competition, as well as the wider socio-technical context. The case study deviates on three points from the multi-level perspective. These deviations are used to conceptualize a particular transition pathway, called 'de-alignment and re-alignment'
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