Inverse Research Papers - Academia.edu (original) (raw)

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each... more

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each effect size, but in practice these weights have to be estimated, being affected by sampling error. When assuming a random-effects model, there are two alternative procedures for averaging independent effect sizes: Hunter and Schmidt’s estimator, which consists of weighting by sample size as an approximation to the optimal weights; and Hedges and Vevea’s estimator, which consists of weighting by an estimation of the inverse variance of each effect size. In this article, the bias and mean squared error of the two estimators were assessed via Monte Carlo simulation of meta-analyses with the standardized mean difference as the effect-size index. Hedges and Vevea’s estimator, although slightly biased, achieved the best performance in terms of the mean square...

The so-called passive' participle in NENA dialects is said to function as both passive and active. This apory is resolved once it is shown that it is neither one or the other, namely that the opposition is not diathetic to begin with but... more

The so-called passive' participle in NENA dialects is said to function as both passive and active. This apory is resolved once it is shown that it is neither one or the other, namely that the opposition is not diathetic to begin with but aspectual. Tha so-called passive participle is perfect(ive) and the so-called active one is imperfect(ive). Transitivity, or rather valency, is narrowly linked to that, and in this language so are ergativity and case.

In this study, without using the assumption a-1 > 0, it is shown that E is lattice - and algebra - isometric isomorphic to the reals R whenever E is a Banach lattice f-algebra with unit e, |e| = 1, in which for every a > 0 the... more

In this study, without using the assumption a-1 > 0, it is shown that E is lattice - and algebra - isometric isomorphic to the reals R whenever E is a Banach lattice f-algebra with unit e, |e| = 1, in which for every a > 0 the inverse a-1 exists. Subsequently, an alternative proof to a result of Huijsmans is given for Banach lattice algebras.

This paper describes the application of the adjoint method to the history matching problem in reservoir engineering. The history matching problem consists in adjusting a set of parameters, in this case the permeability distribution, in... more

This paper describes the application of the adjoint method to the history matching problem in reservoir engineering. The history matching problem consists in adjusting a set of parameters, in this case the permeability distribution, in order to match the data obtained with the simulator to the actual production data in the reservoir. Several numerical experiments are presented which show that

In this paper, we introduce the one-two descriptor. The one-two descriptors is the sum of the vertex contributions such that each pendant vertex contributes 1, each vertex of degree two adjacent to pendant vertex contributes 2, and each... more

In this paper, we introduce the one-two descriptor. The one-two descriptors is the sum of the vertex contributions such that each pendant vertex contributes 1, each vertex of degree two adjacent to pendant vertex contributes 2, and each vertex of degree higher than two also contributes 2. We test this descriptor on the benchmark data set of the octane isomers proposed by the International Academy of Mathematical Chemistry. We show that this descriptor is a good predictor of the heat capacity at P constant (CP) and of the total surface area (TSA). Linear model predictions for both these properties are better then predictions of any of the benchmark descriptors proposed by International Academy of Mathematical Chemistry. Linear model predictions of TSA are also better then predictions of any of Adriatic descriptors, while linear model predictions of CP are not as good as predictions by Adriatic descriptor called inverse sum lordeg index. We also analyze the mathematical properties of this descriptor and we find tight upper and lower bounds in the families of the trees with n vertices and the chemical trees with n vertices.

The distorted Born iterative method (DBI) is used to solve the inverse scattering problem in the ultrasound tomography with the objective of determining a scattering function that is related to the acoustical properties of the region of... more

The distorted Born iterative method (DBI) is used to solve the inverse scattering problem in the ultrasound tomography with the objective of determining a scattering function that is related to the acoustical properties of the region of interest (ROI) from the disturbed waves measured by transducers outside the ROI. Since the method is iterative, we use Born approximation for the first estimate of the scattering function. The main problem with the DBI is that the linear system of the inverse scattering equations is ill-posed. To deal with that, we use two different algorithms and compare the relative errors and execution times. The first one is Truncated Total Least Squares (TTLS). The second one is Regularized Total Least Squares method (RTLS-Newton) where the parameters for regularization were found by solving a nonlinear system with Newton method. We simulated the data for the DBI method in a way that leads to the overdetermined system. The advantage of RTLS-Newton is that the computation of singular value decomposition for a matrix is avoided, so it is faster than TTLS, but it still solves the similar minimization problem. For the exact scattering function we used Modified Shepp-Logan phantom. For finding the Born approximation, RTLS-Newton is 10 times faster than TTLS. In addition, the relative error in L2-norm is smaller using RTLS-Newton than TTLS after 10 iterations of the DBI method and it takes less time.

Abstract. We prove that we can uniquely recover the coefficient of a one dimensional heat equation from a finite set of measurements and provide a constructive procedure for its recovery. The algorithm is based on the well known... more

Abstract. We prove that we can uniquely recover the coefficient of a one dimensional heat equation from a finite set of measurements and provide a constructive procedure for its recovery. The algorithm is based on the well known Gelfand-Levitan-Gasymov inverse spectral theory of Sturm-...

Today many different natural materials are being effectively used in the acoustics and noise control domain. In this study, the acoustical characterization of three different types of natural jute felt material is performed by an... more

Today many different natural materials are being effectively used in the acoustics and noise control domain. In this study, the acoustical characterization of three different types of natural jute felt material is performed by an experimental method and by using the Dunn and Davern model, along with an inverse characterization method. There are many empirical models available in the literature which describes the acoustical behavior of specific material accurately, as they are specially developed for that material. In this study, the possibility of using only the air flow resistivity based Delany–Bazley model and the Dunn–Davern model for acoustical performance prediction of jute material is tested. However, these two models do not show good matching with the experimental data throughout the frequency range of interest. Particularly in the low frequency region, the level of mismatch between experimental and model data is high. Therefore the inverse prediction of the coefficients [Fo...

We investigated how thermal stress may alter the locomotor phenotype of barramundi, Lates calcarifer , from genetically distinct northern (low latitude) and southern (high latitude) populations in tropical Australia. Following early... more

We investigated how thermal stress may alter the locomotor phenotype of barramundi, Lates calcarifer , from genetically distinct northern (low latitude) and southern (high latitude) populations in tropical Australia. Following early growth and development under native (25 °C and 30 °C) and non-native (20 °C and 35 °C) temperatures, we observed distinct differences in the swimming performance of northern and southern individuals that were consistent with expectations based on local thermal adaptation. Southern population fish exhibited significantly faster swimming speeds (32.10 ± 0.33 cm·s–1, mass-adjusted mean ± 95% confidence limit) than their northern counterparts (28.58 ± 0.64 cm·s–1) under cold-stress (20 °C) conditions. Conversely, northern population fish performed significantly better (51.63 ± 2.1 cm·s–1) than their southern counterparts (44.18 ± 3.11 cm·s–1) under heat-stress (35 °C) conditions. We conclude that L. calcarifer display locomotor phenotypes thermally adapted t...

Let T be an aperiodic and repetitive tiling of Rd with finite local complexity. Let Ω be its tiling space with canonical transversal Ξ. The tiling equivalence relation RΞ is the set of pairs of tilings in Ξ which are translates of each... more

Let T be an aperiodic and repetitive tiling of Rd with finite local complexity. Let Ω be its tiling space with canonical transversal Ξ. The tiling equivalence relation RΞ is the set of pairs of tilings in Ξ which are translates of each others, with a certain (étale) topology. In this paper RΞ is reconstructed as a generalized “tail equivalence ” on a Bratteli dia-gram, with its standard AF-relation as a subequivalence relation. Using a generalization of the Anderson–Putnam complex (Bellissard et al. in Commun. Math. Phys. 261:1–41, 2006) Ω is identified with the inverse limit of a sequence of finite CW-complexes. A Bratteli diagram B is built from this sequence, and its set of infinite paths ∂B is homeomorphic to Ξ. The diagram B is endowed with a horizontal structure: additional edges that encode the adjacencies of patches in T. This allows to define an étale equivalence relation RB on ∂B which is homeomorphic to RΞ, and contains the AF-relation of “tail equivalence”.

Magnetoencephalography (MEG) can be used to reconstruct neuronal activity with high spatial and temporal resolution. However, this reconstruction problem is ill-posed, and requires the use of prior constraints in order to produce a unique... more

Magnetoencephalography (MEG) can be used to reconstruct neuronal activity with high spatial and temporal resolution. However, this reconstruction problem is ill-posed, and requires the use of prior constraints in order to produce a unique solution. At present there are a multitude of inversion algorithms, each employing different assumptions, but one major problem when comparing the accuracy of these different approaches is that often the true underlying electrical state of the brain is unknown. In this study, we explore one paradigm, retinotopic mapping in the primary visual cortex (V1), for which the ground truth is known to a reasonable degree of accuracy, enabling the comparison of MEG source reconstructions with the true electrical state of the brain. Specifically, we attempted to localize, using a beanforming method, the induced responses in the visual cortex generated by a high contrast, retinotopically varying stimulus. Although well described in primate studies, it has been an open question whether the induced gamma power in humans due to high contrast gratings derives from V1 rather than the prestriate cortex (V2). We show that the beanformer source estimate in the gamma and theta bands does vary in a manner consistent with the known retinotopy of V1. However, these peak locations, although retinotopically organized, did not accurately localize to the cortical surface. We considered possible causes for this discrepancy and suggest that improved MEG/magnetic resonance imaging co-registration and the use of more accurate source models that take into account the spatial extent and shape of the active cortex may, in future, improve the accuracy of the source reconstructions.

ABSTRACT In the present work, the application of reversed-flow inverse gas chromatography (RF-IGC) to adsorption studies related to heterogeneous catalytic processes on noble metal supported catalysts is reviewed. RF-IGC methodologies are... more

ABSTRACT In the present work, the application of reversed-flow inverse gas chromatography (RF-IGC) to adsorption studies related to heterogeneous catalytic processes on noble metal supported catalysts is reviewed. RF-IGC methodologies are technically simple and they are combined with suitable mathematical treatments which give the possibility for studying the kinetics of catalyzed surface reactions, as well as the topography and the nature of the active sites of solid catalysts. Adsorption parameters, such as rate constants, adsorption energies, adsorption entropies, local isotherms, surface diffusion coefficients, lateral interaction energies and energy distribution functions, are simultaneously determined by RF-IGC. The potential of the novel methodologies has been evaluated by utilising as model systems CO adsorption/oxidation over well-studied Pt–Rh/SiO2 and nanosized-Au/γ-Al2O3 catalysts. The main findings are presented and future goals are also discussed.