7,318 research outputs found
Inferring a collective concept of research from the actions of the art and design research community
This article examines output types as manifestations of different concepts of research. We compare the UK academic scene to that of Brazil, identifying the former as responding ‘bottom-up’ to researcher needs and the latter determining ‘top-down’ what researchers can do. Taking the UK model as indicative of what researchers think they need, we undertook a detailed analysis of the output types used in RAE2008 across all subjects in order to see which types were used and by whom. We also undertook a further analysis of the use of traditional, text-based formats in art and design, and the use of non-traditional, non-textual output types in other subjects. We conclude that both the journal format and the exhibition format are expressive of the understanding each community has of the meaning of research as an activity. This is further reinforced by the national structures within which research is undertaken and evaluatedPeer reviewedSubmitted Versio
Learning from the positive to reduce rural poverty: institutional innovations in agricultural and natural resources research and development
This paper argues that opportunities for reducing poverty, improving social inclusion,
and influencing policy and institutional changes are being missed as a result of not
learning sufficiently from development practitioners who have been effective in
bringing about positive changes in the past. Cautionary tales, positive deviance,
innovations systems and aid ethnographic literature is reviewed. Three agricultural
and natural resources case studies of positive experiences are described. These cover
the spread of bamboo tubewells in eastern Bihar, changes in rice research policy and
the rice innovation system in Nepal, and the spread of groups and group based
organisations and federations in Nepal. These are used to illustrate how institutional
innovations at macro levels came about and gave rise to positive development
outcomes. Implications for innovations theory and for rural development practice are
discussed
Solar sail formation flying for deep-space remote sensing
In this paper we consider how 'near' term solar sails can be used in formation above the ecliptic plane to provide platforms for accurate and continuous remote sensing of the polar regions of the Earth. The dynamics of the solar sail elliptical restricted three-body problem (ERTBP) are exploited for formation flying by identifying a family of periodic orbits above the ecliptic plane. Moreover, we find a family of 1 year periodic orbits where each orbit corresponds to a unique solar sail orientation using a numerical continuation method. It is found through a number of example numerical simulations that this family of orbits can be used for solar sail formation flying. Furthermore, it is illustrated numerically that Solar Sails can provide stable formation keeping platforms that are robust to injection errors. In addition practical trajectories that pass close to the Earth and wind onto these periodic orbits above the ecliptic are identified
Development, fabrication and test of a high purity silica heat shield
A highly reflective hyperpure ( 25 ppm ion impurities) slip cast fused silica heat shield material developed for planetary entry probes was successfully scaled up. Process development activities for slip casting large parts included green strength improvements, casting slip preparation, aggregate casting, strength, reflectance, and subscale fabrication. Successful fabrication of a one-half scale Saturn probe (shape and size) heat shield was accomplished while maintaining the silica high purity and reflectance through the scale-up process. However, stress analysis of this original aggregate slip cast material indicated a small margin of safety (MS. = +4%) using a factor of safety of 1.25. An alternate hyperpure material formulation to increase the strength and toughness for a greater safety margin was evaluated. The alternate material incorporates short hyperpure silica fibers into the casting slip. The best formulation evaluated has a 50% by weight fiber addition resulting in an 80% increase in flexural strength and a 170% increase in toughness over the original aggregate slip cast materials with comparable reflectance
Functional centrality in graphs
In this paper we introduce the functional centrality as a generalization of
the subgraph centrality. We propose a general method for characterizing nodes
in the graph according to the number of closed walks starting and ending at the
node. Closed walks are appropriately weighted according to the topological
features that we need to measure
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