523 research outputs found
Multiple jumps and vacancy diffusion in a face-centered cubic metal
The diffusion of monovacancies in gold has been studied by computer
simulation. Multiple jumps have been found to play a central role in the atomic
dynamics at high temperature, and have been shown to be responsible for an
upward curvature in the Arrhenius plot of the diffusion coefficient.
Appropriate saddle points on the potential energy surface have been found,
supporting the interpretation of vacancy multiple jumps as distinct migration
mechanisms.Comment: 16 page
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Bioinspired scattering materials: light transport in anisotropic, disordered systems
The study of light propagation in disordered media has attracted the interest of many researchers for its relevance to fundamental and applied problems, ranging from imaging through turbid media to the fabrication of white paint. Scattering in a disordered system is determined by the spatial distribution and the scattering properties of its building blocks. To date, most efforts on scattering optimisation have focused on isotropic, high refractive index systems. This thesis investigates the importance of anisotropy in increasing the scattering efficiency of a system, with a particular focus on low refractive index media and their use as sustainable, white materials.
Nature provides a striking example of how to exploit anisotropy to achieve scattering optimisation: with the intra-scale chitin network of the beetle genus Cyphochilus. In this thesis, after showing that this network exhibits the highest scattering efficiency found in nature thus far, a systematic numerical investigation was performed to understand the importance of both single-particle and structural anisotropy in scattering optimisation. In particular, this numerical analysis unveiled that ensembles of anisotropic particles show higher reflectance compared to their isotropic counterpart, whilst using less material.
Based on these findings, the optical properties of bioinspired, scattering systems â obtained both via polymer phase separation and a combination of sequential vacuum filtration and freeze-drying â were investigated. Notably, the reported materials achieve scattering properties comparable to those found in nature, showcasing the potential of using biopolymers to produce sustainable, biocompatible white materials. In addition, the presented bioinspired systems are an interesting platform for fundamental studies, allowing to investigate light transport in anisotropic media.European Research Council grant awarded to Dr Silvia Vignolin
DOUBLE LOOP LEARNING ELEVATES THE INNOVATION DESIGN OF A PAEDIATRIC CLINIC FROM MEDIA TO INTERSUBJECTIVE DIALOGUE
We investigate the innovations actually enacted in an organisational research intervention, to identify double loop learning instances, as a counsellor-facilitator engages in therapeutic co-construction with the client. The case is situated in a paediatric clinic for children with developmental differences. Ethnography lasted three month of full immersion of the researcher-facilitator-counsellor. Followed by a co-construction process between counsellor and client to let emerge innovation design ideas. A number of double loop learning instances came to modify the practice culture of the clinic. Outstanding was the focus emerged on the intersubjective dialogue as the key element to boost impact of relational emotional interaction experiences with the child and with the parent. Other crisp concepts include attention to: breakdown in the relation with parents; dead or live speech as intentional communication style used with parents; more articulated and structured treatment notes reporting therapy sessions; first and second order cybernetic assessments; plus a variety of advices. The onset of focus on intersubjective dialogue, to further develop the clinical practice, the most striking outcome, contributed by the client. The impulse applied to therapist training, its greatest consequence. Significative the thrust towards assessing impact and nature of the clinical practice
SOCIAL PRACTICE DESIGN (SPD), PATHOS, IMPROVISATION, MOOD, AND BRICOLAGE: THE MEDITERRANEAN WAY TO MAKE PLACE FOR IT?
Our proposal for Social Practice Design (SPD), i.e., the design of social practices â in itself a social design activity -, seeks to ensure that the potential benefits of envisioned novel technologies can be realized, by increasing the bias towards the social in Information Systems Development (ISD).
SPD is a form of intervention research or action research based on counselling. It can be considered an extension of Participatory Design (PD) approaches to the implementation phase of information systems. It regards the concept and participative introduction of new things to do, or of new ways to do things, by humans, in order to make place for technology (Ehn 2006), and in order to resolve a variety of other pending social problems in organisations.
In this paper we present SPD as a fully phenomenology-based approach, we reason about its stand in the IS discipline, and we briefly describe and point to an application for a European research project.
What characterize our position in defining SPD are Claudio Ciborraâs Pathos, Improvisation, Caretaking, Bricolage, and other key concepts he puts forth in order to shift the ISD focus from âmethodâ, and direct it âon human existence and everyday lifeâ (Ciborra 2002). We are motivated in this choice by the quest for more impact of ISD research on ISD practice, and our belief that phenomenology and counselling are the right recipe ingredients for this.
The approach of Social Practice Design is based on the idea that problem solutions are in the hands of the organisationâs personnel, and that person centred counselling approaches are capable of empowering them and support them to success.
It is well known that social practices cannot be âengineeredâ but that they are evolving as part of peopleâs activities of integrating a new technology into their ways of doing. Using the word âdesignâ we wish to stress intentionality, proactiveness, creativity and planning as necessary ingredients of organisational innovation processes; i.e., we underline the usefulness of the cognition of the necessity of a conscious design approach to the development of innovative social practices. Thus, our choice of an oxymoron in the SPD title.
In structure, SPD is similar to any methodology for the social, i.e., it includes multiple perspectives into the usual triad of scientific paradigms: observation, analysis, and synthesis. Its core actions reside in the two basic phases of the âdesignâ approach for innovating social practices: âą an ethnographic analysis phase to identify outstanding problems in the area of social practice âą a creative design phase for developing social practice innovations
We judge the quality of the SPD approach by three requirements (Baskerville and Myers 2004): a contribution to practice (the action), a contribution to research (the theory), the criteria by which to judge the research, and we show explicitly how the research in the case meets these criteria
A SECOND STEP BACK FOR MANAGING AMBIGUITY BESIDES REDUCING UNCERTAINTY
This paper is an attempt to chronicle and evaluate the struggle to innovate, to understand and to produce a sustainable response to the pressing problems of the care and protection of an aging population. In that struggle, quite distinct world views of the lived experience of the older person and their families and carers, the pressures and challenges of practitioners, on managers and planners and on the politicians who strive to improve the experience of life of their constituents and the desire of technicians to design and build something useful and interesting come together not in a rational orchestration of interests but in the agonistics of real life. The reality of the distinction between what we have called North-South, hierarchical. and East-West, peer and partnership behaviours and attitudes, between Gregory Batesonâs distinctions of first order and second order processes and deutero versus acquisitive learning together with the need to support and nurture sense making and co-production are very apparent in the experience of the project. The challenges of maintaining an appropriate balance have been significant and are ongoing. We have tried to describe, and provide some detailed evidence for, a style of intervention which we have claimed takes a step further than what is usually conceived of as participative design. This is not based on a reallocation of rights and capabilities between architect/designers and client/users in what are still linear or iterative but two sided design processes. Such reallocations still leave the definition of the objectives and the contexts of development as preconditions of design and assume that the architectural language and conceptual framework are available to the participants in which the problem and the solution can be articulated. In circumstances where these assumptions cannot be safely made, there is a need for an intervention which has the purpose of addressing this lack. In our classification of development processes, this necessarily implies the creation of what we have called East-West occasions which are furnished with material, exhibits and provocations around which the participants can engage with each other in sense making and the co-construction of a shared language
A participatory design approach for the development of support environments in eGovernment services to citizens
The introduction of eGovernment services and applications leads to major changes in the structure and operation of public administrations. In this paper we describe the work in progress in an Italian project called âSPO.T.â aimed at the analysis, development, deployment and evaluation of tools and environments to support the people who plan, deliver, use and evaluate user-centred provision of One-Stop-Shop services to citizens. The âSPO.T.â project has focused on two requirements: 1. the support tools and environments must facilitate the active involvement of all stakeholders in the definition and evolution of eGovernment applications and services, and it is argued that through participatory design changes of structure, process and culture can be delivered effectively; 2. they must embody a set of architecturally coherent resources which reflect the new roles and relationships of public administration and which are sufficiently generic to be relevant to a wide range of local contexts across the community
HERDING CATS: OR MODEL-BASED ALIGNMENT OF HETEROGENEOUS PRACTICES
This paper reports on a study of how practitioners in engineering design try to develop and use models of the design space of the enterprise in support of collaborative work within global production networks. The paper also examines the difficulties they face in developing these models
Fight Risk with Risk: Relexivity of Risk and Globalization in IS
In this paper, we address the following research question: âHow can we understand the nature of risk in IS projects in the context of globalization?â Based on a case study conducted over a period of two years in a Norwegian hospital on the development and implementation of a Electronic Patient Record (EPR), the paper contributes to the current discussion on the conceptualization of risk in IS projects. Drawing upon the concept of reflexive modernization (Beck 1999) the paper makes two key contributions: firstly, it shows the limits of current risk management approaches in understanding the nature of new risks in IS generated by globalization processes; secondly, it suggest a possible theoretical framework for analyzing such nature. The research question is addressed by providing a historical and contingent analysis of the risk management dynamics emerging from the case
From Hyperlinks to Hypercues : Entity-Based Affordances for Fluid Information Exploration
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