The geostatistical treatment of continuous variables often includes a transformation to normal scores. In the case of analysing a composition, it has been suggested that standard methods can be ...applied to (isometric) logratio transformed compositions. Several logratio transformations are available and invariance of the final results under the choice of logratio transform is desirable. However, a geostatistical procedure which includes marginal normal scores transformations of the individual logratio scores via quantile matching will not have this invariance property, nor will the resulting vectors of scores show a joint multivariate normal distribution. In this paper an affine-equivariant normal score transform is proposed. The method is based on a continuous deformation of the underlying logratio space to a Gaussian space. The properties and performance of this method are illustrated and compared with existing alternatives using a simulated setting and a case study from a banded iron formation ore mining operation from Western Australia. The proposed method is also suitable for the study of other multivariate non-compositional cases.
Ensemble Kalman filters (EnKFs) are a successful tool for estimating state variables in atmospheric and oceanic sciences. Recent research has prepared the EnKF for parameter estimation in groundwater ...applications. EnKFs are optimal in the sense of Bayesian updating only if all involved variables are multivariate Gaussian. Subsurface flow and transport state variables, however, generally do not show Gaussian dependence on hydraulic log conductivity and among each other, even if log conductivity is multi‐Gaussian. To improve EnKFs in this context, we apply nonlinear, monotonic transformations to the observed states, rendering them Gaussian (Gaussian anamorphosis, GA). Similar ideas have recently been presented by Béal et al. (2010) in the context of state estimation. Our work transfers and adapts this methodology to parameter estimation. Additionally, we address the treatment of measurement errors in the transformation and provide several multivariate analysis tools to evaluate the expected usefulness of GA beforehand. For illustration, we present a first‐time application of an EnKF to parameter estimation from 3‐D hydraulic tomography in multi‐Gaussian log conductivity fields. Results show that (1) GA achieves an implicit pseudolinearization of drawdown data as a function of log conductivity and (2) this makes both parameter identification and prediction of flow and transport more accurate. Combining EnKFs with GA yields a computationally efficient tool for nonlinear inversion of data with improved accuracy. This is an attractive benefit, given that linearization‐free methods such as particle filters are computationally extremely demanding.
Key Points
Apparent non‐linearity of observed data removed by empirical transformation
This is an implicit pseudo‐linearization for improved EnKF results
First application of EnKFs to hydraulic tomography, unprecedented resolution
The Parisian Convent of the Minims at Place Royale (today's Place des Vosges) has always attracted the curiosity of architectural historians and scholars of representation, having been almost ...completely destroyed between the end of the 19th century and the beginning of the 20th century. Its story begins in 1609, when the religious Order managed to buy 7500 square meters of former Hotel des Tournelles’ land. Even if already in possession of other two Convents in the rural areas of Nigeon and Vincennes (fig. 1), the Minims aspired to have their own institutional headquarters in city center, to better spread their apostolic work and to expand their researches between art and science. Starting from the faint traces survived to the present day, an unprecedented digital reconstruction of the entire Convent have been attempted. The intersection of archival sources was laborious and not without exegetical risks implicit in the choices made to produce a model compatible with the material collected and with the urban limits identified in the historical layout of the city. The main focus of this work of anastylosis, however, was the reconstruction of the lost optical-perspective marvels there contained, praised for their virtuosity and technical-expressive mastery. These, depicting St. John the Evangelist and the Penitent Magdalene, were executed in the first half of the 17th century by Jean François Niceron, and completed by Emmanuel Maignan. This essay is dedicated to the reconstruction of these and other projective, catoptrical and astrolabic tour de forces, offering scholars an unprecedented and surprising journey into one of the most mysterious places of the baroque Paris.DOI: https://doi.org/10.20365/disegnarecon.27.2021.1
•We propose a dynamic adaptive anamorphosis method based on non-linear projections.•Anamorphic rendering of a selective object with normal view rendering of the rest.•The VIP guest results in an ...improved gaze and engagement estimation.•This is performed without sacrificing the other guests’ viewing experience.•We discuss different viewpoints and the spatial relationship between objects.
Anamorphosis for 2D displays can provide viewer centric perspective viewing, enabling 3D appearance, eye contact and engagement, by adapting dynamically in real time to a single moving viewer’s viewpoint, but at the cost of distorted viewing for other viewers. We present a method for constructing non-linear projections as a combination of anamorphic rendering of selective objects whilst reverting to normal perspective rendering of the rest of the scene. Our study defines a scene consisting of five characters, with one of these characters selectively rendered in anamorphic perspective. We conducted an evaluation experiment and demonstrate that the tracked viewer centric imagery for the selected character results in an improved gaze and engagement estimation. Critically, this is performed without sacrificing the other viewers’ viewing experience. In addition, we present findings on the perception of gaze direction for regularly viewed characters located off-center to the origin, where perceived gaze shifts from being aligned to misalignment increasingly as the distance between viewer and character increases. Finally, we discuss different viewpoints and the spatial relationship between objects.
The satiric world of Gulliver’s Travels is one of uncertainties and unresolved dualities. This essay argues that, in a homothetic manner, critical discourse on Gulliver’s Travels should be governed ...by a similar logic, one that reclaims contradiction as its essential logic. Just as Gulliver’s relentlessly single vision cannot adequately account for the realities that he encounters, univocal interpretative strategies fail to render the complexity of Swift’s masterpiece, whose lack of moral assertiveness and maze‑like deceptiveness paradoxically make for its endurance.
En este artículo nos centramos en el estudio, a través de una investigación experimental, de tres propuestas diseñadas para la previsualización de instalaciones pictóricas anamórficas aplicadas a ...espacios arquitectónicos. Tras el análisis de las metodologías desarrolladas desde el siglo XVI hasta la actualidad, presentamos el desarrollo de nuevos procedimientos metodológicos, a través del software de diseño gráfico vectorial y de modelado virtual Sketchup, que permite generar tanto la deformación que debe aplicarse a la imagen original para generar la anamorfosis, estableciendo los parámetros de medida como distancias y ángulos, como la previsualización del resultado final en el espacio virtual. Cada uno de los casos experimentados es diferente, y nos ofrece unos resultados únicos. De esta forma, las conclusiones obtenidas se deben a los procedimientos y las finalidades que nos han llevado a utilizar dicho programa. Así, resulta de gran interés la facilidad que Sketchup presenta para generar este tipo de proyectos, de manera que ofrece una metodología más intuitiva que las tradicionales, y, en consecuencia, permite la creación de instalaciones anamórficas sin necesidad de conocer todos y cada uno de los parámetros técnicos necesarios en un principio. Esta investigación sirve como precedente de futuros estudios en los que analicemos la aplicación directa de la anamorfosis en entornos urbanos, modificando el paisaje a través de esta.
Few-layer black phosphorus was recently rediscovered as a narrow-bandgap atomically thin semiconductor, attracting unprecedented attention due to its interesting properties. One feature of this ...material that sets it apart from other atomically thin crystals is its structural in-plane anisotropy which manifests in strongly anisotropic transport characteristics. However, traditional angle-resolved conductance measurements present a challenge for nanoscale systems, calling for new approaches in precision studies of transport anisotropy. Here, we show that the nonlocal response, being exponentially sensitive to the anisotropy value, provides a powerful tool for determining the anisotropy in black phosphorus. This is established by combining measurements of the orientation-dependent nonlocal resistance response with the analysis based on the anamorphosis relations. We demonstrate that the nonlocal response can differ by orders of magnitude for different crystallographic directions even when the anisotropy is at most order-one, allowing us to extract accurate anisotropy values.
The study focuses on the definition of a geometric methodology for the use of catoptric anamorphosis in contemporary architecture. The particular projective phenomenon is illustrated, showing ...typological-geometric properties, responding to mechanisms of light reflection. It is pointed out that previous experience, over the centuries, employed the technique, relegating its realisation exclusively to reflecting devices realised by simple geometries, on a small scale and almost exclusively for convex mirrors. Wanting to extend the use of the projective phenomenon and experiment with the expressive potential on reflective surfaces of a complex geometric free-form nature, traditional geometric methods limit the design and prior control of the results, thus causing the desired effect to fail. Therefore, a generalisable methodological process of implementation is proposed, defined through the use of algorithmic-parametric procedures, for the determination of deformed images, describing possible subsequent developments.
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