6,691 research outputs found
(Oniscidea: Armadillidae) on the Australian East Coast
No full textLee, Timothy R. C., Ho, Simon Y. W., Wilson, George D. F., Lo, Nathan (2014): Phylogeography and diversity of the terrestrial isopod Spherillo grossus (Oniscidea: Armadillidae) on the Australian East Coast. Zoological Journal of the Linnean Society 170 (2): 297-309, DOI: 10.1111/zoj.12105, URL: http://dx.doi.org/10.1111/zoj.1210
Nonlinear properties of optical microfibres
No full textGlass microfibre waveguides offer an intriguing platform for the investigation of nonlinear effects, due to their high effective nonlinearity which arises from the tight modal confinement down to dimensions comparable to the wavelength of guided light. This thesis presents theoretical and experimental work towards achieving efficient third and second harmonic generation in silica microfibres, as well as in microfibre loop resonators for enhancing the conversion. Since microfibre resonators themselves exhibit interesting nonlinear behaviour, the polarisation dependent properties of microcoil resonators were also studied. Efficient third harmonic generation is possible through intermodal phase matching, and experiments using short tapers have demonstrated significant efficiencies up to 10-3 over a uniform 4 mm waist. On the other hand, the interrogation of longer tapers, in which the harmonic generation occurs within the taper transition regions of several cm rather than the waist, allows for a broadband conversion observed to exceed 36 nm at the 5 dB bandwidth level. A straightforward technique to improve efficiency using microfibre loop resonators was also investigated. Near resonance, the recirculation of the pump power inside the resonator was experimentally shown to increase conversion by 7.7 dB higher than that of the straight microfibre, similar to simulated predictions, and by optimising the loop geometry the resonant efficiency enhancement can potentially reach 20 dB.Simulations on second harmonic generation in microfibres indicate that the second order nonlinearity originates primarily from the structural anisotropy at the glass-air boundary (which exploits the high surface electric field strength of microfibres) as well as multipolar effects within the bulk. To overcome the inherent weakness of these effects, experiments focused on conversion enhancement via the aforementioned technique using loop resonators, with a measured 7.6 dB efficiency improvement.In addition, an accurate polarisation dependent model for microcoils was developed for both the linear and nonlinear regimes by incorporating the effects of fibre twist and birefringence. The coupling between orthogonally polarised modes propagating along the microcoil results in a strongly polarisation sensitive transmission, especially near resonances, which in turn influences the nonlinear hysteresis characteristics
Heterolepisma Escherich 1905
No full textHeterolepisma Escherich, 1905 Heterolepisma Escherich, 1905: 63. Type species: Lepisma pampeana Silvestri, 1902 by subsequent designation (Paclt, 1967: 25). Isolepisma Escherich, 1905: 61. Notolepisma Tillyard, 1924: 241.Published as part of Smith, Graeme B., Mitchell, Andrew, Lee, Timothy R. C. & Espinasa, Luis, 2019, DNA Barcoding and Integrative Taxonomy of the Heterolepisma sclerophylla species complex (Zygentoma: Lepismatidae: Heterolepismatinae) and the Description of Two New Species, pp. 1-32 in Records of the Australian Museum 71 (1) on page 14, DOI: 10.3853/j.2201-4349.71.2019.1677, http://zenodo.org/record/383797
Heterolepisma highlandi Smith 2014
No full textHeterolepisma highlandi Smith 2014 Heterolepisma highlandi Smith, 2014: 16. Type material (paratype). 1 juvenile ♀ (HW 0.88) (AMS K. 377604 in ethanol) NSW: Wee Jasper, 35.0591°S 148.6489°E 552 m asl, 21.viii.2010, Graeme Smith and Phil Fleming.Published as part of Smith, Graeme B., Mitchell, Andrew, Lee, Timothy R. C. & Espinasa, Luis, 2019, DNA Barcoding and Integrative Taxonomy of the Heterolepisma sclerophylla species complex (Zygentoma: Lepismatidae: Heterolepismatinae) and the Description of Two New Species, pp. 1-32 in Records of the Australian Museum 71 (1) on page 14, DOI: 10.3853/j.2201-4349.71.2019.1677, http://zenodo.org/record/383797
Two essays in asset pricing
No full textThe first essay, Knowledge Capital and Innovation Efficiency Effects on Stock Returns, provides a novel framework for understanding innovation in the asset pricing literature. Prior research shows that stock returns are increasing in firms' innovative efficiency. In a dynamic model of investment in physical and knowledge capital, this effect can arise rationally as innovative efficiency amplifies risks associated with investment and investors require compensation for these risks. I identify operating leverage and expansion option channels as the main drivers of the risk premium. Simulations of panels of firms with heterogeneous technology can reproduce the economic magnitude of the empirical return effect. The model further implies that the effect should be stronger for firms with high operating leverage and low book-to-market ratios. These predictions are supported by the data.
The second essay, Operating Leverage, R&D Intensity, and Stock Returns, studies interaction effects of operating leverage and R&D intensity on stock returns. A production-based asset pricing model with knowledge capital has an implication that R&D intensive firms earn higher expected stock returns among high fixed costs firms. An investment strategy that bought R&D intensive firms and sold R&D weak firms earn 0.67% to 1.26% per month in high fixed cost portfolios, while the strategy is not profitable in low fixed costs portfolios. In regression analysis, one standard deviation increase in R&D expenditures is associated with 1.85% to 2.12% increase in yearly stock returns for above median fixed costs firms. By the recursive nature of knowledge capital accumulation, the value of knowledge capital itself is sensitive to the economic situation. R&D intensive firms' values aggravate faster with fixed costs in bad times and investors require compensation for the risk. In short, the value of knowledge capital itself is risky, R&D intensive firms are more exposed to the risky nature of knowledge capital, and fixed costs amplify the risk.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo termsThe student, Jangwook Lee, accepted the attached license on 2017-04-17 at 15:16.The student, Jangwook Lee, submitted this Dissertation for approval on 2017-04-17 at 15:31.This Dissertation was approved for publication on 2017-04-18 at 10:18.DSpace SAF Submission Ingestion Package generated from Vireo submission #10817 on 2017-08-10 at 13:41:24Made available in DSpace on 2017-08-10T19:15:16Z (GMT). No. of bitstreams: 2
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Previous issue date: 2017-04-1
Figure 4 in Phylogeography and diversity of the terrestrial isopod Spherillo grossus (Oniscidea: Armadillidae) on the Australian East Coast
No full textFigure 4. Light microscope images of the penes covers of 14 Spherillo grossus specimens. Images taken from the ventral side. Each specimen is labelled with a three-letter code followed by a number. The number refers to the specific specimen (see Table S2). Three-letter codes refer to localities: BAT, Batemans Bay; BRI, Brisbane; MAN, North Manly; NOW, Nowra; OAT, Oatley; PYM, Pymble; URU, Urunga. Scale bar: 400 μm.Published as part of Lee, Timothy R. C., Ho, Simon Y. W., Wilson, George D. F. & Lo, Nathan, 2014, Phylogeography and diversity of the terrestrial isopod Spherillo grossus (Oniscidea: Armadillidae) on the Australian East Coast, pp. 297-309 in Zoological Journal of the Linnean Society 170 (2) on page 305, DOI: 10.1111/zoj.12105, http://zenodo.org/record/489053
Increasing Distributed Generation Penetration using Soft Normally-Open Points
No full textThis paper considers the effects of various voltage control solutions on facilitating an increase in allowable levels of distributed generation installation before voltage violations occur. In particular, the voltage control solution that is focused on is the implementation of `soft' normally-open points (SNOPs), a term which refers to power electronic devices installed in place of a normally-open point in a medium-voltage distribution network which allows for control of real and reactive power flows between each end point of its installation sites. While other benefits of SNOP installation are discussed, the intent of this paper is to determine whether SNOPs are a viable alternative to other voltage control strategies for this particular application. As such, the SNOPs ability to affect the voltage profile along feeders within a distribution system is focused on with other voltage control options used for comparative purposes. Results from studies on multiple network models with varying topologies are presented and a case study which considers economic benefits of increasing feasible DG penetration is also given
Heterolepisma buntonorum Smith 2016
No full text<i>Heterolepisma buntonorum</i> Smith 2016 <p> <i>Heterolepisma buntonorum</i> Smith 2016a: 58.</p> <p> <b>Material examined</b>. 1♀ (HW 1.43) (AMS K.261244 K.261245 on two slides) TAS: Knocklofty, 42.8752°S 147.2957°E 270 m asl, 13.ii.2016, Stephen Bunton.</p>Published as part of <i>Smith, Graeme B., Mitchell, Andrew, Lee, Timothy R. C. & Espinasa, Luis, 2019, DNA Barcoding and Integrative Taxonomy of the Heterolepisma sclerophylla species complex (Zygentoma: Lepismatidae: Heterolepismatinae) and the Description of Two New Species, pp. 1-32 in Records of the Australian Museum 71 (1)</i> on page 14, DOI: 10.3853/j.2201-4349.71.2019.1677, <a href="http://zenodo.org/record/3837977">http://zenodo.org/record/3837977</a>
Polarisation effects in optical microcoil resonators
No full textOptical microcoil resonators (OMRs) fabricated by wrapping a microfibre around a rod to allow evanescent coupling between adjacent turns as in Fig 1. (a) have recently attracted much interest due to their high Q-factor and large extinction ratios resonances, low input and output coupling losses, large evanescent field and compactness [1,2], with applications such as sensing [3] and signal processing [4]. However, theoretical models published so far have neglected polarisation effects, and hence in order to develop a more detailed understanding we have modelled the OMR with polarisation-dependent coupled mode equations in the linear [5] and nonlinear regimes
Evaluating Research Impact through Open Access to Scholarly Communication
No full textScientific research is a competitive business – in order to secure funding, promotion and tenure researchers must demonstrate their work has impact in their field. To maximise impact researchers undertake high priority research, aim to get results first, and publish in the highest impact journals. The Internet now presents a new opportunity to the scholarly author seeking higher impact: s/he can now make their work instantly accessible on the Web through author self-archiving. This growing body of open access literature (coupled with new publishing models that make journals available for-free to the reader) maximises research impact by maximising the number of people who can read it, and making it available sooner. Open access also provides a new opportunity for bibliometric research. This thesis describes the relatively recent phenomenon of open access to research literature, tools that were built to collect and analyse that literature, and the results of analyses of the effect of open access and its effect on author behaviour. It shows that articles self-archived by authors receive between 50-250% more citations, that rapid pre-printing on the Web has dramatically reduced the peak citation rate from over a year to virtually instant and how citation-impact – now widely used for evaluation – can be expanded to include a new web metric of download impact
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