21 research outputs found
Agent-Based Modelling: The Next 15 Years
This short note makes recommendations for the future direction of research in agent-based modelling (ABM). It is a personal view based on my experience as a policy adviser who has recently come to ABM. I suggest that to promote the use of ABM, the ABM community needs demonstrate the value of modelling to other social scientists by showing-by-doing and offering training projects; and to produce tools, guidance on good-practice and basic building blocks. Then the policy contexts most likely to benefit from ABM need to be identified along with any new data requirements, so that the usefulness of ABM can be demonstrated to policy analysts. This is, in my view, the challenge facing the ABM community for the next 15 years.Agent-Based Modelling,, NetLogo, Policy Advice
The social shaping of British communications networks prior to the First World War
'Diese Arbeit wendet Konzepte der Sozialwissenschaften auf die Entwicklung der Telekommunikation Großbritanniens vor dem Ersten Weltkrieg an. Betrachtet werden die gesellschaftliche Prägung der Technologie, soziale Netzwerke und die Unterscheidung zwischen kurz- und langfristigen Effekten. Zwei Fallstudien mit Bezug zur Telekommunikation im Großbritannien des 19. Jahrhunderts - die telegraphische Verbindung nach Indien und das Telefon - werden dann mithilfe dieser Konzepte untersucht. Dabei wird behauptet, dass Kommunikationsnetze aus bestehenden sozialen bzw. geschäftlichen Netzwerken entstehen, die wiederum frühere Kommunikations- und Transportnetze reflektieren, und dass die wichtigste sofortige Wirkung eines neuen Kommunikationsmittels der zunehmende Informationsaustausch zwischen existierenden Kontakten ist, während sich auf lange Sicht neue Praktiken entwickeln.' (Autorenreferat)'This paper applies concepts from the social sciences to the evolution of communications in Britain before the First World War: the social shaping of technology, social networks and the distinction between short and long term effects. Two cases studies relating to communications in nineteenth century Britain - the telegraphic link to India and phones - are then examined in the light of these concepts. It is argued that communication networks grow out of existing social/ business networks, which in turn reflect previous communication and transport networks, and that the main immediate effect of a new mode is to increase communication with existing contacts while in the longer run, new practices develop.' (author's abstract
The Social Shaping of British Communications Networks prior to the First World War
"Die soziale Prägung der britischen Telekommunikationsnetzwerke vor dem Ersten Weltkrieg". This paper applies concepts from the social sciences to the evolution of communications in Britain before the First World War: the social shaping of technology, social networks and the distinction between short and long term effects. Two cases studies relating to communications in nineteenth century Britain – the telegraphic link to India and phones – are then examined in the light of these concepts. It is argued that communication networks grow out of existing social/business networks, which in turn reflect previous communication and transport networks, and that the main immediate effect of a new mode is to increase commuwhile in the longer run, new practices develop.</p
A Conceptualization of e-Risk Perceptions and the Offline-Online Risk Trade-Off for Small Firm Internationalization
A sound conceptualization of international e-risks has grown in demand, because of the increasing penetration of the Internet, and specifically the enabling-facility of the Internet technology for small firms. Yet, to date, there has been no study explicitly attempting to build an international business risk framework for the online environment, nor to explain online internationalization decisions. The purpose of the present paper is threefold, (1) to combine and complement the existing traditional international risk constructs and the emerging views on e-business risks into a comprehensive and unified international risk framework for the online context; (2) to develop propositions regarding SMEs’ active online internationalization decisions by drawing on Dunning's OLI framework; and (3) to explore the online–offline risk trade-off inherent in online internationalization decisions by integrating the e-risk framework into the eclectic paradigm
Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial
Background
Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects.
Methods
FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762.
Findings
Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months.
Interpretation
Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function.
Funding
UK Stroke Association and NIHR Health Technology Assessment Programme
The Social Shaping of British Communications Networks prior to the First World War
"Die soziale Prägung der britischen Telekommunikationsnetzwerke vor dem Ersten Weltkrieg". This paper applies concepts from the social sciences to the evolution of communications in Britain before the First World War: the social shaping of technology, social networks and the distinction between short and long term effects. Two cases studies relating to communications in nineteenth century Britain – the telegraphic link to India and phones – are then examined in the light of these concepts. It is argued that communication networks grow out of existing social/business networks, which in turn reflect previous communication and transport networks, and that the main immediate effect of a new mode is to increase commuwhile in the longer run, new practices develop.</p
Communications, Travel and Social Networks since 1840 : A study Using Agent-based Models
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Different ways of modelling phone adoption
Systems dynamics and agent-based models are used here to examine the spread of fixed line phones in Britain over 120 years. Both models approximately fit the data and it is shown that in this case the two approaches can be used to complement each other. The SD model is simpler and produces a better fit while its deterministic nature facilitates sensitivity analysis. The agent-based model provides greater explanatory power, which can in turn be used to fine tune the systems dynamics model. Together, they can be combined to tell a plausible story about the adoption of telephones.</p
Communications, Travel and Social Networks since 1840: A Study Using Agent-Based Models.
This thesis investigates the dynamics of the relationship between personal communications and travel, using agent-based computer simulation modelling. It focuses on the interaction between social, communication and transport networks. The novelty of the thesis lies in using this new modelling technique to identify the important factors underlying this relationship, to get a better understanding of why communication and travel have grown together, and to address the question ‘Why are communication and travel complements, not substitutes?’ A new way of modelling social networks is presented, based on social circles, which reflects the characteristics of social networks better than the standard network models. This social network model is then used as the basis for three case studies, drawing on qualitative and quantitative secondary data. The first case study looks at the development of mail from 1840 to the start of the First World War; the second at fixed-line phones from 1951 to 2001; and the third at mobile communications and the internet from 1998 to 2007, with forecasts to 2021. The key conclusion is that communication networks evolve out of social networks as does travel for social purposes. When a new communications technology is introduced, affordability is always an initial constraint on take-up, but in the nineteenth century literacy was also important, as is ‘digital literacy’ in the late twentieth and early twenty-first centuries. Literacy enables people to keep in touch with those who are geographically remote and this communication is likely to engender travel. Because the internet facilitates meeting new people, this effect is strengthened in contrast to earlier communication modes which have in general only facilitated contact between people who are already known to one another