2,002 research outputs found
'But I thought we were friends?' Life cycles and research relationships
This chapter is concerned with a relatively under-explored aspect of ‘engaged research’ – the nature of friendship relations between researchers and practitioners, and the ethical dilemmas that arise in such relationships. Attention has been paid to the relational aspects of research in the methodology literature, but this chapter focuses more closely on friendship in particular. The chapter is framed around two guiding concerns: how do friendships, formed in and around research, change over time; and in view of friendship conceived in this dynamic fashion, what ethical questions and dilemmas arise for the ‘friends’
Parallel spinors and holonomy groups
In this paper we complete the classification of spin manifolds admitting
parallel spinors, in terms of the Riemannian holonomy groups. More precisely,
we show that on a given n-dimensional Riemannian manifold, spin structures with
parallel spinors are in one to one correspondence with lifts to Spin_n of the
Riemannian holonomy group, with fixed points on the spin representation space.
In particular, we obtain the first examples of compact manifolds with two
different spin structures carrying parallel spinors.Comment: 10 pages, LaTeX2
Graph-Embedding Empowered Entity Retrieval
In this research, we improve upon the current state of the art in entity
retrieval by re-ranking the result list using graph embeddings. The paper shows
that graph embeddings are useful for entity-oriented search tasks. We
demonstrate empirically that encoding information from the knowledge graph into
(graph) embeddings contributes to a higher increase in effectiveness of entity
retrieval results than using plain word embeddings. We analyze the impact of
the accuracy of the entity linker on the overall retrieval effectiveness. Our
analysis further deploys the cluster hypothesis to explain the observed
advantages of graph embeddings over the more widely used word embeddings, for
user tasks involving ranking entities
The Strong Energy Condition and the S-Brane Singularity Problem
Recently it has been argued that, because tachyonic matter satisfies the
Strong Energy Condition [SEC], there is little hope of avoiding the
singularities which plague S-Brane spacetimes. Meanwhile, however, Townsend and
Wohlfarth have suggested an ingenious way of circumventing the SEC in such
situations, and other suggestions for actually violating it in the S-Brane
context have recently been proposed. Of course, the natural context for
discussions of [effective or actual] violations of the SEC is the theory of
asymptotically deSitter spacetimes, which tend to be less singular than
ordinary FRW spacetimes. However, while violating or circumventing the SEC is
necessary if singularities are to be avoided, it is not at all clear that it is
sufficient. That is, we can ask: would an asymptotically deSitter S-brane
spacetime be non-singular? We show that this is difficult to achieve; this
result is in the spirit of the recently proved "S-brane singularity theorem".
Essentially our results suggest that circumventing or violating the SEC may not
suffice to solve the S-Brane singularity problem, though we do propose two ways
of avoiding this conclusion.Comment: 13 pages, minor corrections and improvements, references adde
Processing and Linking Audio Events in Large Multimedia Archives: The EU inEvent Project
In the inEvent EU project [1], we aim at structuring, retrieving, and sharing large archives of networked, and dynamically changing, multimedia recordings, mainly consisting of meetings, videoconferences, and lectures. More specifically, we are developing an integrated system that performs audiovisual processing of multimedia recordings, and labels them in terms of interconnected “hyper-events ” (a notion inspired from hyper-texts). Each hyper-event is composed of simpler facets, including audio-video recordings and metadata, which are then easier to search, retrieve and share. In the present paper, we mainly cover the audio processing aspects of the system, including speech recognition, speaker diarization and linking (across recordings), the use of these features for hyper-event indexing and recommendation, and the search portal. We present initial results for feature extraction from lecture recordings using the TED talks. Index Terms: Networked multimedia events; audio processing: speech recognition; speaker diarization and linking; multimedia indexing and searching; hyper-events. 1
Realistic Earth escape strategies for solar sailing
With growing interest in solar sailing comes the requirement to provide a basis for future detailed planetary escape mission analysis by drawing together prior work, clarifying and explaining previously anomalies. Previously unexplained seasonal variations in sail escape times from Earth orbit are explained analytically and corroborated within a numerical trajectory model. Blended-sail control algorithms, explicitly independent of time, which providenear-optimal escape trajectories and maintain a safe minimum altitude and which are suitable as a potential autonomous onboard controller, are then presented. These algorithms are investigated from a range of initial conditions and are shown to maintain the optimality previously demonstrated by the use of a single-energy gain control law but without the risk of planetary collision. Finally, it is shown that the minimum sail characteristic acceleration required for escape from a polar orbit without traversing the Earth shadow cone increases exponentially as initial altitude is decreased
Working capital management : theory and evidence from New Zealand listed limited liability companies
The theory of working capital management contends that if working capital is managed according to prescriptive theory then it would be expected that businesses would invest in working capital, finance working capital, monitor factors that influence working capital, manage cash, accounts receivable, inventory, accounts payable, the cash conversion cycle (aggregative approach), and measure and analyze performance to ensure that the long term (fixed) assets are utilized effectively and efficiently. This thesis seeks to shed light on the problem, how working capital is managed by New Zealand listed limited liability companies. This is achieved by applying New Zealand data collected by means of a postal questionnaire to an empirical working capital management model. The main findings indicate that businesses in New Zealand consider working capital management an important issue, yet a large group of respondents ignored the survey. It is evident that the respondents placed greater emphasis or importance on the financing decision, with the investment decision largely taken for granted. Some effort is made prima facie to manage cash, accounts receivable, inventory and accounts payable independently of each other. However given the theory of working capital management, there may be room for improvement regarding the strategies, tactics and techniques used to manage these components. Furthermore, the findings suggest that working capital management is also strategic as it impact on the liquidity, solvency/bankruptcy, efficiency, profitability and shareholder wealth maximization of the business. In light of the findings, it was recommended that an in-depth case study research approach can enhance the survey questionnaire to further investigate the findings. Further research should focus on the levels, composition, structure, and performance of working capital and introduce financial data for this purpose. It is evident from the results of the study that the purpose and function of working capital are not clearly and sufficiently recognized, and that it is quite likely that deficiencies and insufficiencies in the management of working capital in New Zealand may be revealed by further empirical research
Circulating interleukin-10 and risk of cardiovascular events: a prospective study in the elderly at risk
<p><b>Objective:</b> The goal of this study was to examine the association of the antiinflammatory interleukin-10 (IL-10) with risk of cardiovascular disease (CVD).</p>
<p><b>Methods and Results:</b> In the PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) cohort, we related baseline concentrations of circulating IL-10 to risk of CVD events in a nested case (n=819)-control (n=1618) study of 3.2 years of follow-up. Circulating IL-10 showed few strong associations with classical risk factors but was positively correlated with IL-6 and C-reactive protein. IL-10 was positively associated with risk of CVD events (odds ratio [OR] 1.17, 95% CI 1.05 to 1.31 per unit increase in log IL-10) after adjusting for classical risk factors and C-reactive protein. Furthermore, IL-10 was associated more strongly with CVD risk among those with no previous history of CVD (OR 1.42, 95% CI 1.18 to 1.70), compared with those with previous CVD (OR 1.04, 95% CI 0.90 to 1.19; P=0.018). Overall, IL-10 showed a modest ability to add discrimination to classical risk factors (C-statistic +0.005, P=0.002).</p>
<p><b>Conclusion:</b> Baseline circulating levels of the antiinflammatory IL-10 are positively associated with risk of CVD among the elderly without prior CVD events, although the association is less evident in those with a history of CVD. Additional epidemiological and mechanistic studies investigating the role of IL-10 in CVD are warranted.</p>
Stringy Stability of Charged Dilaton Black Holes with Flat Event Horizon
Electrically charged black holes with flat event horizon in anti-de Sitter
space have received much attention due to various applications in Anti-de
Sitter/Conformal Field Theory (AdS/CFT) correspondence, from modeling the
behavior of quark-gluon plasma to superconductor. Crucial to the physics on the
dual field theory is the fact that when embedded in string theory, black holes
in the bulk may become vulnerable to instability caused by brane
pair-production. Since dilaton arises naturally in the context of string
theory, we study the effect of coupling dilaton to Maxwell field on the
stability of flat charged AdS black holes. In particular, we study the
stability of Gao-Zhang black holes, which are locally asymptotically anti-de
Sitter. We find that for dilaton coupling parameter > 1, flat black
holes are stable against brane pair production, however for 0 < < 1,
the black holes eventually become unstable as the amount of electrical charges
is increased. Such instability however, behaves somewhat differently from that
of flat Reissner-Nordstr\"om black holes. In addition, we prove that the
Seiberg-Witten action of charged dilaton AdS black hole of Gao-Zhang type with
flat event horizon (at least in 5-dimension) is always logarithmically
divergent at infinity for finite values of , and is finite and positive
in the case tends to infinity . We also comment on the robustness of
our result for other charged dilaton black holes that are not of Gao-Zhang
type.Comment: Fixed some confusions regarding whether part of the discussions
concern electrically charged hole or magnetically charged one. No changes to
the result
- …