Search results for "transformation"
showing 10 items of 1634 documents
Integral Imaging Monitors with an Enlarged Viewing Angle
2015
Enlarging the horizontal viewing angle is an important feature of integral imaging monitors. Thus far, the horizontal viewing angle has been enlarged in different ways, such as by changing the size of the elemental images or by tilting the lens array in the capture and reconstruction stages. However, these methods are limited by the microlenses used in the capture stage and by the fact that the images obtained cannot be easily projected into different displays. In this study, we upgrade our previously reported method, called SPOC 2.0. In particular, our new approach, which can be called SPOC 2.1, enlarges the viewing angle by increasing the density of the elemental images in the horizontal …
Computation of microimages for plenoptic display
2014
We report a new algorithm for the generation of the microimages ready for their projection into an integral imaging monitor. The algorithm is based in the transformation properties of the plenoptic field captured with an array of digital cameras. We show that a small number of cameras can produce the microimages for displaying 3D scenes with resolution and parallax fully adapted to the monitor features.
3D integral imaging display by smart pseudoscopic-to-orthoscopic conversion (SPOC).
2010
Previously, we reported a digital technique for formation of real, non-distorted, orthoscopic integral images by direct pickup. However the technique was constrained to the case of symmetric image capture and display systems. Here, we report a more general algorithm which allows the pseudoscopic to orthoscopic transformation with full control over the display parameters so that one can generate a set of synthetic elemental images that suits the characteristics of the Integral-Imaging monitor and permits control over the depth and size of the reconstructed 3D scene.
Three-Dimensional Kinematics during the Take-Off Phase in Competitive Long Jumping
2013
The purpose of the present study was to identify the relationships among selected kinematic variables that affect the take-off phase and performance in elite jumpers. The jump distance was found to be related to: I) the athlete's approach speed before the instant of touch down; and ii) the exchange in spatial velocity components at take-off, which results in a gain in maximum vertical velocity of the centre of mass (CM), favoured by the use of an optimum touch-down angle of the take-off leg, an active landing of the foot at touch-down, and a motion of the take-off leg during the compression phase that helps to manage the loss of horizontal velocity. Nonetheless, the results show that an ad…
Approximate renormalization-group transformation for Hamiltonian systems with three degrees of freedom
1999
We construct an approximate renormalization transformation that combines Kolmogorov-Arnold-Moser (KAM)and renormalization-group techniques, to analyze instabilities in Hamiltonian systems with three degrees of freedom. This scheme is implemented both for isoenergetically nondegenerate and for degenerate Hamiltonians. For the spiral mean frequency vector, we find numerically that the iterations of the transformation on nondegenerate Hamiltonians tend to degenerate ones on the critical surface. As a consequence, isoenergetically degenerate and nondegenerate Hamiltonians belong to the same universality class, and thus the corresponding critical invariant tori have the same type of scaling prop…
An extended Darboux transformation to get families of solutions to the KPI equation
2023
By means of a Darboux transform with particular generating function solutions to the Kadomtsev-Petviashvili equation (KPI) are constructed. We give a method that provides different types of solutions in terms of particular determinants of order N. For any order, these solutions depend of the degree of summation and the degree of derivation of the generating functions. We study the patterns of their modulus in the plane (x, y) and their evolution according time and parameters.
Do nonmelanoma skin cancers develop from extra-cutaneous stem cells?
2008
A hypothesis is presented that nonmelanoma skin cancers can develop from extra-cutaneous stem cells, and not exclusively from skin keratinocytes. This idea is supported by recent findings regarding the initiation of cancers in the digestive tract, and by a cancer stem cell model of a neoplasia. It is known that multipotent adult progenitor cells can trans-differentiate into very diverse cellular lineages and can be recruited to areas of profound tissue injury. In these settings, they might also initiate malignant transformation. Some epidemiological data and recent findings regarding mechanisms of wound healing indicate that skin cancers could also originate from bone marrow-derived or othe…
Rottlerin induces a transformed phenotype in human keratinocytes.
2001
PKCdelta plays a fundamental role in cell cycle control. Consistent with its proposed tumour suppressor function, ras transfection of the human keratinocyte cell line HaCaT results in a loss of PKCdelta expression mediated by TGFalpha (Exp. Cell Res., 219, 299, 1995). To get more insight into the role of PKCdelta in keratinocytes, we investigated the effects of Rottlerin, a specific inhibitor of protein kinase Cdelta, in HaCaT cells. After Rottlerin treatment, HaCaT cells lost their cobble-stone morphology and displayed a spindle-shaped, fibroblastic phenotype. Additionally, the establishment of cell-cell contacts was prevented. This was caused by an internalization of E-cadherin and beta-c…
Fluorinated Heterocyclic Compounds. An Effective Strategy for the Synthesis of Fluorinated Z-Oximes of 3-Perfluoroalkyl-6-phenyl-2H-1,2,4-triazin- 5-…
2005
The reaction of 3-benzoyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydrazine has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of the hydrazine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure with enlargement, leads with high yield and in very mild experimental conditions to the formation of Z-oximes of 3-perfluoroalkyl-6-phenyl-2H-1,2,4-triazin-5-ones (11a-c) as major products of the reaction. In turn, the hydrazine can attack the electrophilic carbonyl carbon giving 4-perfluoroacylamino-5-phenyl-2H-1,2,3-triazoles (13a-c) through the well-known Boulton-Katritzky rearrangement of the inter…
How Digital is Communication in Your Organization?
2006
Novel innovations in the area of digital media are changing the ways we communicate and organize. However, few practical measures exist for analysing the digitalisation of organizational communication as an intermediate factor in the initiatives to adopt new information and communication technologies (ICT). Building upon the genre theory of organizational communication, a categorization of communication forms, and quantitative measures we suggest such metrics and a measurement method. A case study applying them in an industrial organization suggests the method and metrics to be applicable for quantifying how new information systems affect to organizational communication as well as for antic…