School of Mathematics and Physics - UQ eSpace
http://espace.library.uq.edu.au/
The University of QueenslandenFez http://blogs.law.harvard.edu/tech/rssО разложениях по собственным функциям нелинейного оператора Штурма-Лиувилля с краевыми условиями, зависящими от спектрального параметра
http://espace.library.uq.edu.au/view/UQ:271124
2012-03-22T12:15:16Z
Makin, A. S.; Thompson, H. B. 2-critical sets for a class of groups
http://espace.library.uq.edu.au/view/UQ:65581
2007-08-15T01:33:26Z
Khodkar, A.; Shahabi, M. A.; Sheikholeslami, S. M. 2-manifold recognition is in logspace
http://espace.library.uq.edu.au/view/UQ:381444
2016-03-06T10:03:24Z
Burton, Benjamin A.; Elder, Murray; Kalka, Arkadius; Tillmann, Stephan 2-perfect m-cycle systems can be defined by single laws
http://espace.library.uq.edu.au/view/UQ:71175
2007-08-15T03:50:04Z
Khodkar, A.; Zahrai, S. 3-[(2-Chlorophenyl)sulfonylamino]-2-cyano-N-93,5-dimethoxyphenyl)-3-methylsulfanyl-2-propenamide
http://espace.library.uq.edu.au/view/UQ:73956
2007-08-15T04:56:30Z
Kennard, C. H.; McFadden, H. G.; Byriel, K. 3-Lie algebras with an ideal N
http://espace.library.uq.edu.au/view/UQ:179878
We define the hypo-nilpotent ideal in n-Lie algebras and obtain all solvable 3-Lie algebras with an m-dimensional simplest filiform 3-Lie algebra as a maximal hypo-nilpotent ideal. We prove that the dimension of such solvable 3-Lie algebras is at most m+2, and there is no solvable 3-Lie algebra with the simplest filiform 3-Lie algebra as the nilradical.2009-08-18T10:22:52Z
Bai, Rui-pu; Shen, Cai-hong; Zhang, Yao-Zhong 4GOOD - Technology and prototype for a 4th-Generation Omni-purpose Optical Disc system
http://espace.library.uq.edu.au/view/UQ:192144
Digital optical data storage has become firmly established through CD, DVD and their derivatives. Future mobile and stationary multimedia applications demand for ever higher storage density, even beyond HD-DVD and Blu-ray Disc with 50 GB maximum storage capacity (dual layer). While holographic recording is in the far future for the consumer domain, the 4th generation of optical storage is being heralded by a leap in technology. Within a European initiative in the scope of the EUREKA project MobileDRIVE and the project 4GOOD (4th-Generation Omni-purpose Optical Disc-system), funded by the German Ministry of Economy and Technology, the fundamental technologies are being developed for high-density optical data storage (60... 100 Gbit/inch(2) in order to achieve at least 200 GB on a 12 cm disc, or e.g. > 5 GB on a 3 cm miniaturised version (single layer). The contribution describes the technology objectives, challenges, concepts and project status in the key areas of disc development, drive including laser, optics, acceleration sensors for mobile operation, and signal processing.2010-01-12T10:09:13Z
Hepper, D.; Richter, H.; Knappmann, S.; Eyberg, R.; Knittel, J.; Frerichs, M.; Franke, A.; Gahn, C.; Hyot, B.; Bruneau, J.-M.; Lell, A.; Behringer, M.; Forst, M.; Wolter, K.; Wuttig, M.; Semar, W. 5-cycle decompositions from paired 3- and 4-cycle decompositions
http://espace.library.uq.edu.au/view/UQ:266067
Let (V,T) be a 3-fold triple system and (V,C) a 4-fold 4-cycle system on the same set V. This choice of indices 3 and 4 ensures that each system contains the same number of cycles: {pipe}T{pipe} = {pipe}C{pipe}. We pair up the cycles, {t, c}, where t ∈ T and c ∈ C, in such a way that t and c share one edge. If t = (x, y, z) and c = (x, y, u, v), so t and c share the edge {x, y}, then we retain the 5-cycle (z, x, v, u, y) and remove the repeated edge {x, y}. Doing this for all the pairs {t, c}, we rearrange all the shared edges, common to t and c, into further 5-cycles, so that the result is a 7-fold 5-cycle system on V. The necessary conditions are that the order {pipe}V {pipe} is 1 or 5 (mod 10); these conditions are shown to be sufficient for such a "metamorphosis" from pairs of 3- and 4-cycles into 5-cycles.2012-01-25T11:53:28Z
Billington, Elizabeth J. A basis for the symplectic group branching algebra
http://espace.library.uq.edu.au/view/UQ:273452
2012-04-30T20:49:09Z
Kim, Sangjib; Yacobi, Oded A Bayesian decision approach for sample size determination in phase II trials
http://espace.library.uq.edu.au/view/UQ:221215
Stallard (1998, Biometrics 54, 279-294) recently used Bayesian decision theory for sample-size determination in phase II trials. His design maximizes the expected financial gains in the development of a new treatment. However, it results in a very high probability (0.65) of recommending an ineffective treatment for phase III testing. On the other hand, the expected gain using his design is more than 10 times that of a design that tightly controls the false positive error (Thall and Simon, 1994, Biometrics 50, 337-349). Stallard's design maximizes the expected gain per phase II trial, but it does not maximize the rate of gain or total gain for a fixed length of time because the rate of gain depends on the proportion of treatments forwarding to the phase III study. We suggest maximizing the rate of gain, and the resulting optimal one-stage design becomes twice as efficient as Stallard's one-stage design. Furthermore, the new design has a probability of only 0.12 of passing an ineffective treatment to phase III study.2010-11-17T13:53:49Z
Leung, Denis Heng-Yan; Wang, You-Gan A Bayesian-Decision Theoretic Approach to Model Error Modeling.
http://espace.library.uq.edu.au/view/UQ:162877
Abstract: This paper takes a Bayesian-decision theoretic approach to transfer function estimation, nominal model estimation, and quantification of the resulting model error. Consistency of the nonparametric estimate of the transfer function is proved together with a rate of convergence. The required quantities can be computed routinely using reversible jump Markov chain Monte Carlo methods. The proposed methodology has connections with set membership identification which has been extensively studied for this problem.2009-02-04T11:23:34Z
McVinish, Ross S.; Braslavsky, .Julio H.; Mengersen, Kerrie L. A benchmark for evaluation of algorithms for identification of cellular correlates of clinical outcomes
http://espace.library.uq.edu.au/view/UQ:379762
The Flow Cytometry: Critical Assessment of Population Identification Methods (FlowCAP) challenges were established to compare the performance of computational methods for identifying cell populations in multidimensional flow cytometry data. Here we report the results of FlowCAP-IV where algorithms from seven different research groups predicted the time to progression to AIDS among a cohort of 384 HIV+ subjects, using antigen-stimulated peripheral blood mononuclear cell (PBMC) samples analyzed with a 14-color staining panel. Two approaches (FlowReMi.1 and flowDensity-flowType-RchyOptimyx) provided statistically significant predictive value in the blinded test set. Manual validation of submitted results indicated that unbiased analysis of single cell phenotypes could reveal unexpected cell types that correlated with outcomes of interest in high dimensional flow cytometry datasets.2016-02-16T01:05:06Z
Aghaeepour, Nima; Chattopadhyay, Pratip; Chikina, Maria; Dhaene, Tom; Van Gassen, Sofie; Kursa, Miron; Lambrecht, Bart N.; Malek, Mehrnoush; McLachlan, G. J.; Qian, Yu; Qiu, Peng; Saeys, Yvan; Stanton, Rick; Tong, Dong; Vens, Celine; Walkowiak, Slawomir; Wang, Kui; Finak, Greg; Gottardo, Raphael; Mosmann, Tim; Nolan, Garry P.; Scheuermann, Richard H.; Brinkman, Ryan R. Aberration compensation using nematic liquid crystals
http://espace.library.uq.edu.au/view/UQ:197019
2010-02-26T16:02:45Z
Somalingam, S.; Hain, M.; Tschudi, T.; Knittel, J.; et al. A Bethe ansatz study of the ground state energy for the repulsive Bose-Hubbard dimer
http://espace.library.uq.edu.au/view/UQ:183665
We employ an exact Bethe ansatz solution to study the repulsive Bose–Hubbard dimer model. Using a continuum approximation we solve for the ground state root density and in turn compute the ground state energy per particle. The formula so obtained is accurate for a finite-sized system in the weak coupling limit. Surprisingly, the formula diverges from the numerically calculated value as the number of particles increases. This indicates that the formula fails to predict the ground state energy per particle in the thermodynamic limit.2009-09-04T10:29:40Z
Links, Jon; Zhao, Shao-You Ab initio excited-state dynamics of the photoactive yellow protein chromophore
http://espace.library.uq.edu.au/view/UQ:152412
2008-08-07T11:01:18Z
Ko, C; Levine, B; Toniolo, A; Manohar, L; Olsen, S; Werner, HJ; Martinez, TJ Ab initio study of lithium-doped graphane for hydrogen storage
http://espace.library.uq.edu.au/view/UQ:400828
2016-08-19T10:34:57Z
Hussain, Tanveer; Pathak, Biswarup; Adit Maark, Tuhina; Moyses Araujo, Carlos; Scheicher, Ralph H.; Ahuja, Rajeev A binomial identity on the least prime factor of an integer
http://espace.library.uq.edu.au/view/UQ:260015
An identity for binomial symbols modulo an odd positive integer <span style="line-height:5%"></span> relating to the least prime factor of <span style="line-height:5%"></span> is proved. The identity is discussed within the context of Pell conics.2011-10-30T21:46:18Z
Hambleton, Samuel A. Abiotic and biotic interactions determine whether increased colonization is beneficial or detrimental to metapopulation management
http://espace.library.uq.edu.au/view/UQ:388187
Increasing the colonization rate of metapopulations can improve persistence, but can also increase exposure to threats. To make good decisions, managers must understand whether increased colonization is beneficial or detrimental to metapopulation persistence. While a number of studies have examined interactions between metapopulations, colonization, and threats, they have assumed that threat dynamics respond linearly to changes in colonization. Here, we determined when to increase colonization while explicitly accounting for non-linear dependencies between a metapopulation and its threats. We developed patch occupancy metapopulation models for species susceptible to abiotic, generalist, and specialist threats and modeled the total derivative of the equilibrium proportion of patches occupied by each metapopulation with respect to the colonization rate. By using the total derivative, we developed a rule for determining when to increase metapopulation colonization. This rule was applied to a simulated metapopulation where the dynamics of each threat responded to increased colonization following a power function. Before modifying colonization, we show that managers must understand: (1) whether a metapopulation is susceptible to a threat; (2) the type of threat acting on a metapopulation; (3) which component of threat dynamics might depend on colonization, and; (4) the likely response of a threat-dependent variable to changes in colonization. The sensitivity of management decisions to these interactions increases uncertainty in conservation planning decisions.2016-06-05T00:17:35Z
Southwell, Darren M.; Rhodes, Jonathan R.; McDonald-Madden, Eve; Nicol, Sam; Helmstedt, Kate J.; McCarthy, Michael A. A block successive lower-bound maximization algorithm for the maximum pseudo-likelihood estimation of fully visible Boltzmann machines
http://espace.library.uq.edu.au/view/UQ:380914
Maximum pseudo-likelihood estimation (MPLE) is an attractive method for training fully visible Boltzmann machines (FVBMs) due to its computational scalability and the desirable statistical properties of the MPLE. No published algorithms for MPLE have been proven to be convergent or monotonic. In this note, we present an algorithm for the MPLE of FVBMs based on the block successive lower-bound maximization (BSLM) principle. We show that the BSLM algorithm monotonically increases the pseudo-likelihood values and that the sequence of BSLM estimates converges to the unique global maximizer of the pseudo-likelihood function. The relationship between the BSLM algorithm and the gradient ascent (GA) algorithm for MPLE of FVBMs is also discussed, and a convergence criterion for the GA algorithm is given.2016-03-01T00:25:06Z
Nguyen, Hien D.; Wood, Ian A. A boolean model of the gene regulatory network underlying mammalian cortical area development
http://espace.library.uq.edu.au/view/UQ:218943
2010-10-24T00:03:45Z
Giacomantonio, Clare E.; Goodhill, Geoffrey J. A brief summary of binary quadratic forms
http://espace.library.uq.edu.au/view/UQ:268787
2012-03-02T10:21:28Z
Hambleton, Samuel A. A bright future for quantum communications
http://espace.library.uq.edu.au/view/UQ:189857
Quantum information protocols based on continuous-variable entangled states are attractive because they exploit standard optical modulation and measurement equipment, and do not require single photons. Recent progress in the field is reversing initial concerns about the practicality of the approach.2009-12-13T00:02:52Z
Ralph, Timothy C.; Lam, Ping K. A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L
http://espace.library.uq.edu.au/view/UQ:341579
2014-10-10T19:17:05Z
Bachelet, E.; Fouque, P.; Han, C.; Gould, A.; Albrow, M. D.; Beaulieu, J. -P.; Bertin, E.; Bond, I. A.; Christie, G. W.; Heyrovsky, D.; Horne, K.; Jorgensen, U. G.; Maoz, D.; Mathiasen, M.; Matsunaga, N.; McCormick, J.; Menzies, J.; Nataf, D.; Natusch, T.; Oi, N.; Renon, N.; Tsapras, Y.; Udalski, A.; Yee, J. C.; Batista, V.; Bennett, D. P.; Brillant, S.; Caldwell, J. A. R.; Cassan, A.; Cole, A.; Cook, K. H.; Coutures, C.; Dieters, S.; Dominik, M.; Prester, D. Dominis; Donatowicz, J.; Greenhill, J.; Kains, N.; Kane, S. R.; Marquette, J. -B.; Martin, R.; Pollard, K. R.; Sahu, K. C.; Street, R. A.; Wambsganss, J.; Williams, A.; Zub, M.; Bos, M.; Dong, Subo; Drummond, J.; Gaudi, B. S.; Graff, D.; Janczak, J.; Kaspi, S.; Kozlowski, S.; Lee, C. -U.; Monard, L. A. G.; Munoz, J. A.; Park, B. -G.; Pogge, R. W.; Polishook, D.; Shporer, A.; Abe, F.; Botzler, C. S.; Fukui, A.; Furusawa, K.; Hearnshaw, J. B.; Itow, Y.; Korpela, A. V.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Miyake, N.; Muraki, Y.; Ohnishi, K.; Rattenbury, N. J.; Saito, To.; Sullivan, D.; Sumi, T.; Suzuki, D.; Sweatman, W. L.; Tristram, P. J.; Wada, K.; Allan, A.; Bode, M. F.; Bramich, D. M.; Clay, N.; Fraser, S. N.; Hawkins, E.; Kerins, E.; Lister, T. A.; Mottram, C. J.; Saunders, E. S.; Snodgrass, C.; Steele, I. A.; Wheatley, P. J.; Bozza, V.; Browne, P.; Burgdorf, M. J.; Novati, S. Calchi; Dreizler, S.; Finet, F.; Glitrup, M.; Grundahl, F.; Harpsoe, K.; Hessman, F. V.; Hinse, T. C.; Hundertmark, M.; Liebig, C.; Maier, G.; Mancini, L.; Rahvar, S.; Ricci, D.; Scarpetta, G.; Skottfelt, J.; Southworth, J.; Surdej, J.; Zimmer, F. Absence of a quantum limit to charge diffusion in bad metals
http://espace.library.uq.edu.au/view/UQ:356768
2015-04-26T00:22:12Z
Pakhira, Nandan; McKenzie, Ross H. Absolute absorption line-shape measurements at the shot-noise limit
http://espace.library.uq.edu.au/view/UQ:285420
Here, we report a measurement scheme for determining an absorption profile with an accuracy imposed solely by photon shot noise. We demonstrate the power of this technique by measuring the absorption of cesium vapor with an uncertainty at the 2-ppm level. This extremely high signal-to-noise ratio allows us to directly observe the homogeneous line-shape component of the spectral profile, even in the presence of Doppler broadening, by measuring the spectral profile at a frequency detuning more than 200 natural linewidths from the line center. We then use this tool to discover an optically induced broadening process that is quite distinct from the well-known power broadening phenomenon.2012-11-15T15:00:33Z
Truong, Gar-Wing; Anstie, James D.; May, Eric F.; Stace, Thomas M.; Luiten, Andre N. Absolute proper motions of open clusters: I. Observational data
http://espace.library.uq.edu.au/view/UQ:265898
2012-01-24T11:59:13Z
Baumgardt, H.; Dettbarn, C.; Wielen, R. Abundance, distribution, morphometrics, reproductive aspects and diet of the catshark Holohalaelurus regani
http://espace.library.uq.edu.au/view/UQ:190249
Holohalaelurus regani was caught in 38% of the 3314 bottom trawls conducted during routine demersal surveys o. the South African west and south coasts from 1986 to 1999. An index of biomass for H. regani has increased on the west coast, from 1606 t in 1986–1993 to 3012 t in 1994–1999, despite c. 130 t being taken annually as by–catch in the demersal fishery. On the south coast, there has also been an increase over the same period, from 793 to 1350 t. Females and juveniles were generally found in shallower water (<300 m) than males, suggesting an inshore nursery area. Male H. regani become mature at 450–500 mm LT, whereas females become mature at 400–450 mm LT. There is reproductive activity throughout the year and fecundity appears to be high. This species is a generalist feeder, with the diet comprising teleosts, crustaceans and cephalopods. H. regani also scavenges offal opportunistically. Its high fecundity, the relative protection of females and juveniles in shallow water that is rarely trawled, its opportunistic diet and its robust nature that may allow it to survive after it has been discarded, have enabled H. regani to increase in numbers, despite indirect fishing pressure.2009-12-17T09:20:50Z
Richardson, A. J.; Maharaj, G.; Compagno, L. J. V.; Leslie, R. W.; Ebert, D. A.; Gibbons, M. J. A case study of two clustering methods based on maximum likelihood
http://espace.library.uq.edu.au/view/UQ:309410
2013-09-15T06:39:22Z
Ganesalingam, S.; McLachlan, G. J. A catalogue of the Steiner triple systems of order 19
http://espace.library.uq.edu.au/view/UQ:339526
2014-09-15T10:49:20Z
Kaski, Petteri; Östergård, Patric R. J.; Pottonen, Olli; Kiviluoto, Lasse Acceptor and excitation density dependence of the ultrafast polaron absorption signal in donor-acceptor organic solar cell blends
http://espace.library.uq.edu.au/view/UQ:403200
2016-09-02T19:00:15Z
Zarrabi, Nasim; Burn, Paul L.; Meredith, Paul; Shaw, Paul E. Accommodating dynamic oceanographic processes and pelagic biodiversity in marine conservation planning
http://espace.library.uq.edu.au/view/UQ:228884
2011-02-11T10:30:39Z
Grantham, HS; Game, ET; Lombard, AT; Hobday, AJ; Richardson, AJ; Beckley, LE; Pressey, RL; Huggett, JA; Coetzee, JC; van der Lingen, CD; Petersen, SL; Merkle, D; Possingham, HP Accounting for habitat dynamics in conservation planning
http://espace.library.uq.edu.au/view/UQ:200262
2010-03-22T16:41:29Z
Possingham, Hugh P.; Moilanen, Atte; Wilson, Kerrie Wilson Accounting for individual variability in the von Bertalanffy growth model
http://espace.library.uq.edu.au/view/UQ:221258
2010-11-17T14:09:00Z
Wang, Y. G.; Thomas, M. R. Accuracy in the measurement of magnetic fields using nitrogen-vacancy centers in nanodiamonds
http://espace.library.uq.edu.au/view/UQ:381209
2016-03-02T14:20:52Z
Aman, Haroon; Plakhotnik, Taras Accuracy of single quantum dot registration using cryogenic laser photolithography
http://espace.library.uq.edu.au/view/UQ:193451
We have registered the position of single InGaAs quantum dots using a novel cryogenic laser photolithography technique. This would be useful in realizing solid state cavity quantum electrodynamics. By fabricating metal alignment markers around the quantum dot, it was registered with an accuracy of 50 nm. Following the marker fabrication process we demonstrated that the same quantum dot was reacquired, with an accuracy of 150 nm. The photoluminescence spectra from the quantum dots before and after processing were identical except for a small red shift (~1 nm), probably introduced during the reactive ion etching.2010-01-21T11:41:15Z
Lee, K. H.; Green, A. M.; Brossard, F. S. F.; Taylor, R. A.; Sharp, D. N.; Turberfield, A. J.; Williams, D. A.; Briggs, G. A. D. Accurate costing in mixed integer utilisation mining models
http://espace.library.uq.edu.au/view/UQ:308959
2013-09-12T15:30:52Z
Burt, C.; Chan, Y. Accurate lineshape spectroscopy and the Boltzmann constant
http://espace.library.uq.edu.au/view/UQ:372088
2015-10-27T00:21:49Z
Truong, G.-W.; Anstie, J. D.; May, E. F.; Stace, T. M.; Luiten, A. N. Accurate lower bounds for two-dimensional constraint capacities using corner transfer matrices
http://espace.library.uq.edu.au/view/UQ:308967
2013-09-12T16:53:00Z
Chan, Yao-ban; Rechnitzer, Andrew Accurate measurements of the Raman scattering coefficient and the depolarization ratio in liquid water
http://espace.library.uq.edu.au/view/UQ:300291
2013-05-17T18:43:20Z
Bray, Andrew; Chapman, Robert; Plakhotnik, Taras A central limit theorem for a discrete-time SIS model with individual variation
http://espace.library.uq.edu.au/view/UQ:275777
A discrete-time SIS model is presented that allows individuals in the population to vary in terms of their susceptibility to infection and their rate of recovery. This model is a generalisation of the metapopulation model presented in McVinish and Pollett (2010). The main result of the paper is a central limit theorem showing that fluctuations in the proportion of infected individuals around the limiting proportion converges to a Gaussian random variable when appropriately rescaled. In contrast to the case where there is no variation amongst individuals, the limiting Gaussian distribution has a nonzero mean.2012-06-18T08:16:53Z
McVinish, R.; Pollett, P.K. A Century After A Nobel Prize: The Legacy of Lippmann's Colour Photography
http://espace.library.uq.edu.au/view/UQ:199336
2010-03-16T09:20:31Z
Wegener, M. A CH3CN and HCO+ survey towards southern methanols masers associated with star formation
http://espace.library.uq.edu.au/view/UQ:164151
2009-02-12T13:25:48Z
Purcell, C. R.; Balasubramanyam, R.; Burton, M. G.; Walsh, A. J.; Minier, V.; Hunt-Cunningham, M. R.; Kedziora-Chudczer, L. L.; Longmore, S. N.; Bains, I.; Hill, T.; Barnes, P. J.; Busfield, A. L.; Calisse, P.; Crighton, N. H. M.; Curran, S. J.; Davis, T. M.; Dempsey, J. T.; Derragopian, G.; Fulton, B.; Hidas, M. G.; Hoare, M. G.; Lee, J.-K.; Ladd, E. F.; Lumsden, S. L.; Moore, T. J. T.; Murphy, M. T.; Oudmaijer, R. D.; Pracy, M. B.; Rathborne, J.; Robertson, S.; Schultz, A. S. B.; Shobbrook, J.; Sparks, P. A.; Storey, J.; Travouillion, T. A classical channel model for gravitational decoherence
http://espace.library.uq.edu.au/view/UQ:335121
We show that, by treating the gravitational interaction between two mechanical resonators as a classical measurement channel, a gravitational decoherence model results that is equivalent to a model first proposed by Diosi. The resulting decoherence model implies that the classically mediated gravitational interaction between two gravitationally coupled resonators cannot create entanglement. The gravitational decoherence rate (and the complementary heating rate) is of the order of the gravitationally induced normal mode splitting of the two resonators. Failure to see this in an experiment would rule out treating gravitational interactions as purely classical.2014-07-22T03:24:13Z
Kafri, D.; Taylor, J. M.; Milburn, G. J. A closing scheme for finding almost-invariant sets in open dynamical systems
http://espace.library.uq.edu.au/view/UQ:381387
2016-03-05T10:21:15Z
Froyland, Gary; Pollett, Philip K.; Stewart, Robyn M. A combined measurement of cosmic growth and expansion from clusters of galaxies, the CMB and galaxy clustering
http://espace.library.uq.edu.au/view/UQ:307265
2013-08-25T00:04:17Z
Rapetti, David; Blake, Chris; Allen, Steven W.; Mantz, Adam; Parkinson, David; Beutler, Florian A common factor-analytic model for classification
http://espace.library.uq.edu.au/view/UQ:325219
In this era of data explosion, much research has been directed to the problem of filtering and extracting useful information from extremely large datasets. The focus is on discriminant analysis of high-dimensional data, where the number of dimensions p is very large relative to the number of observations n. Mixture discriminant analysis provides an effective parametric approach, where each class density is modeled using mixtures of common factor analyzers. Although the adoption of mixture models with common factor loadings in the components significantly reduces the number of parameters to be estimated, the number of variables has to be reduced first to a more manageable level. Thus we consider the problem of dimension reduction for high-dimensional data. In this paper, we propose a factor-analytic model with common factor loadings for classification. We apply our model to a breast cancer study involving microarray gene expression data, which shows the parametric approach can select informative genes that improve the prediction of disease outcome.2014-03-11T01:56:37Z
Sun, Mingzhu; McLachlan, Geoffrey J A compact holographic optical tweezers instrument
http://espace.library.uq.edu.au/view/UQ:298984
Holographic optical tweezers have found many applications including the construction of complex micron-scale 3D structures and the control of tools and probes for position, force, and viscosity measurement. We have developed a compact, stable, holographic optical tweezers instrument which can be easily transported and is compatible with a wide range of microscopy techniques, making it a valuable tool for collaborative research. The instrument measures approximately 30×30×35 cm and is designed around a custom inverted microscope, incorporating a fibre laser operating at 1070 nm. We designed the control software to be easily accessible for the non-specialist, and have further improved its ease of use with a multi-touch iPad interface. A high-speed camera allows multiple trapped objects to be tracked simultaneously. We demonstrate that the compact instrument is stable to 0.5 nm for a 10 s measurement time by plotting the Allan variance of the measured position of a trapped 2 μm silica bead.We also present a range of objects that have been successfully manipulated.2013-04-30T16:18:45Z
Gibson, G. M.; Bowman, R. W.; Linnenberger, A.; Dienerowitz, M.; Phillips, D. B.; Carberry, D. M.; Miles, M. J.; Padgett, M. J. A compact laser imaging system for concurrent reflectance confocal microscopy and laser doppler flowmetry
http://espace.library.uq.edu.au/view/UQ:399542
We propose a compact laser feedback interferometry imaging system for concurrent reflectance confocal microscopy and laser Doppler flowmetry. This system acquires both confocal reflectance and Doppler signals in a confocal architecture to image dynamic turbid media with higher contrast than a system operating in either modality, and is coherent in nature. In a confocal optical configuration, reflectance confocal microscopy provides information about scattering from within a small volume centered around the focal point of the confocal system, and laser Doppler flowmetry provides information about the velocity of moving scatterers within the same volume. Raster scanning the sample enables the concurrent creation of two images, containing independent information, from a well specified depth within the sample. Concurrent spatial mapping of these independent sensing modalities affords improvement in the capability of the imaging system by obtaining additional information from both morphological and functional features of the dynamic turbid medium, at depths penetrable by near-infrared lasers. We realize the idea using a laser feedback interferometry imaging system scanning a microfluidic channel which contains a dynamic turbid medium. We show the effectiveness of this integrated imager quantitatively through the improvement of the signal to background ratio of a combined (multiplication) image.2016-08-11T11:59:45Z
Mowla, Alireza; Taimre, Thomas; Lim, Yah Leng; Bertling, Karl; Wilson, Stephen J.; Prow, Tarl W.; Rakic, Aleksandar D. A compactness argument in the additive theory and the polynomial method
http://espace.library.uq.edu.au/view/UQ:268789
2012-03-02T10:45:15Z
Karolyi, Gyula A comparative study of two matrix factorization methods applied to the classification of gene expression rate
http://espace.library.uq.edu.au/view/UQ:229927
In microarray data analysis, dimension reduction is an important consideration in the construction of a successful classification algorithm. As an alternative to feature selection, we use a well-known matrix factorisation method. For example, we can employ the popular singular-value decomposition (SVD) or nonnegative matrix factorization. In this paper, we consider a novel algorithm for gradient-based matrix factorisation (GMF). We compare GMF and SVD in their application to five gene expression datasets. The experimental results show that our method is faster, more stable, and sensitive.2011-02-22T16:18:16Z
Nikulin, Vladimir; Huang, Tian-Hsiang; McLachlan, Geoffrey J.