2,309 research outputs found
Another exact solution for two-dimensional, inviscid sinh Poisson vortex arrays
Arrays of vortices are considered for two-dimensional, inviscid flows when the functional relationship between the stream function and the vorticity is a hyperbolic sine. An exact solution as a doubly periodic array of vortices is expressed in terms of the Jacobi elliptic functions. There is a threshold value of the period parameter such that a transition from globally smooth distributions of vorticity to singular distributions occurs. © 2003 American Institute of Physics.published_or_final_versio
A new approach for sizing trials with composite binary endpoints using anticipated marginal values and accounting for the correlation between components
Composite binary endpoints are increasingly used as primary endpoints in
clinical trials. When designing a trial, it is crucial to determine the
appropriate sample size for testing the statistical differences between
treatment groups for the primary endpoint. As shown in this work, when using a
composite binary endpoint to size a trial, one needs to specify the event rates
and the effect sizes of the composite components as well as the correlation
between them. In practice, the marginal parameters of the components can be
obtained from previous studies or pilot trials, however, the correlation is
often not previously reported and thus usually unknown. We first show that the
sample size for composite binary endpoints is strongly dependent on the
correlation and, second, that slight deviations in the prior information on the
marginal parameters may result in underpowered trials for achieving the study
objectives at a pre-specified significance level. We propose a general strategy
for calculating the required sample size when the correlation is not specified,
and accounting for uncertainty in the marginal parameter values. We present the
web platform CompARE to characterize composite endpoints and to calculate the
sample size just as we propose in this paper. We evaluate the performance of
the proposal with a simulation study, and illustrate it by means of a real case
study using CompARE
Motion and edge adaptive interpolation de-interlacing algorithm
This paper presents a new motion and edge adaptive de-interlacing algorithm, which is efficient and artifacts-free. It is novel in the sense that it introduces a way to properly interpolate the two (odd and even) field images according to the information provided by the simplest form of motion detection and edge orientation estimation methods. The proposed algorithm was evaluated by three video sequences, namely, 'Akiyo', 'Silent', 'Foreman'. Experimental results confirm that the proposed algorithm performs, both objectively and subjectively, much better than other similar algorithms. These promising results indicate that the proposed interpolation approach has good potential to realize even better de-interlacing algorithms, if more sophisticated motion detection and edge orientation estimation methods are employed.postprintThe 10th WSEAS international conference on Computers (ICCOMP'06), Athens, Greece, 13-15 July 2006. In Proceedings of ICCOMP, 2006, p. 1030-103
Enhanced therapeutic efficacy of transarterial chemoembolisation treatment in hepatocelluar carcinoma (HCC) by mTOR inhibitor RAD001: implication for a novel treatment regimen in HCC
Oral Presentationpublished_or_final_versionThe 16th Medical Research Conference, Department of Medicine, the University of Hong Kong, Hong Kong, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17 n. 1, suppl. 1, p. 25, abstract no. 3
Generalized motion and edge adaptive interpolation de-interlacing algorithm
This paper presents a generalized motion and edge adaptive de-interlacing framework, which offers a structured way to develop de-interlacing algorithm. The framework encompasses many typical de-interlacing algorithms, ranging from simple interpolation based algorithms, to more complex edge dependent and motion adaptive algorithms. Based on this framework, we develop a new de-interlacing algorithm which is efficient and artifacts-free. The proposed algorithm was evaluated by five video sequences, namely, "Akiyo", Mother and Daughter", "Silent", "Foreman" and "Stefan". Experimental results confirm that the proposed algorithm performs, both objectively and subjectively, much better than other similar algorithms. These promising results indicate that the proposed framework has good potential for realizing even better de-interlacing algorithms.postprin
Super-resolution of faces using texture mapping on a generic 3D model
This paper proposes a novel face texture mapping framework to transform faces with different poses into a unique texture map. Under this framework, texture mapping can be realized by utilizing a generic 3D face model, standard Haar-like feature based detector, active appearance model and pose estimation algorithm. By this texture map, correspondence of every pixel at the face across multiple distinct input images can then be established, which enables super-resolution algorithms to be applied directly on registered texture map to render high resolution faces. This paper details the proposed framework, and illustrates how the proposed super-resolution algorithm works with the help of weighted average and median filters. Convincing experimental results are also presented to validate the effectiveness of the proposed framework and superresolution algorithm. © 2009 IEEE.published_or_final_versio
Motion and edge adaptive interpolation de-interlacing algorithm
This paper presents a new motion and edge adaptive de-interlacing algorithm, which is efficient and artifacts-free. It is novel in the sense that it introduces a way to properly interpolate the two (odd and even) field images according to the information provided by the simplest form of motion detection and edge orientation estimation methods. The proposed algorithm was evaluated by three video sequences, namely, 'Akiyo', 'Silent', 'Foreman'. Experimental results confirm that the proposed algorithm performs, both objectively and subjectively, much better than other similar algorithms. These promising results indicate that the proposed interpolation approach has good potential to realize even better de-interlacing algorithms, if more sophisticated motion detection and edge orientation estimation methods are employed.postprintThe 10th WSEAS international conference on Computers (ICCOMP'06), Athens, Greece, 13-15 July 2006. In Proceedings of ICCOMP, 2006, p. 1030-103
The evolution of periodic waves of the coupled NLS equations
Session KD: Waves I, Abstract no. KD.007published_or_final_versio
A study on the effect of testosterone replacement on the development of obstructive sleep apnoea (OSA)
published_or_final_versio
Numerical studies of the Lagrangian approach for reconstruction of the conductivity in a waveguide
We consider an inverse problem of reconstructing the conductivity function in
a hyperbolic equation using single space-time domain noisy observations of the
solution on the backscattering boundary of the computational domain. We
formulate our inverse problem as an optimization problem and use Lagrangian
approach to minimize the corresponding Tikhonov functional. We present a
theorem of a local strong convexity of our functional and derive error
estimates between computed and regularized as well as exact solutions of this
functional, correspondingly. In numerical simulations we apply domain
decomposition finite element-finite difference method for minimization of the
Lagrangian. Our computational study shows efficiency of the proposed method in
the reconstruction of the conductivity function in three dimensions
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