scholarly journals The Thinness of the Ocean in S–Θ–p Space and the Implications for Mean Diapycnal Advection

2007 ◽  
Vol 37 (6) ◽  
pp. 1714-1732 ◽  
Author(s):  
Trevor J. McDougall ◽  
David R. Jackett

Abstract It is shown that the ocean’s hydrography occupies little volume in the three-dimensional space defined by salinity–temperature–pressure (S–Θ–p), and the implications of this observation for the mean vertical transport across density surfaces are discussed. Although ocean data have frequently been analyzed in the two-dimensional temperature–salinity (S–Θ) diagram where casts of hydrographic data are often locally tight in S–Θ space, the relatively empty nature of the World Ocean in the three-dimensional S–Θ–p space seems not to have received attention. The World Ocean’s data lie close to a single surface in this three-dimensional space, and it is shown that this explains the known smallness of the ambiguity in defining neutral surfaces. The ill-defined nature of neutral surfaces means that lateral motion along neutral trajectories leads to mean vertical advection through density surfaces, even in the absence of small-scale mixing processes. The situation in which the ocean’s hydrography occupies a large volume in S–Θ–p space is also considered, and it is suggested that the consequent vertical diapycnal advection would be sufficiently large that the ocean would not be steady.

2021 ◽  
Author(s):  
Keiko Yamazaki ◽  
Fujiko Abe ◽  
Ichiro Hagiwara

Abstract The Japanese traditional fan, which is a form of origami originating in Japan with a folding culture, has a variety of three-dimensional expression that differs from two-dimensional expression. The image painted on the fan deforms when the fan is folded. In this study, we create a digital fan model for clarifying the deformation on the fan face according to parameters such as length of the bamboo bones. We then validate the digital model with an actual fan. Furthermore, we obtain the original plan view from images of the folded fan as a reverse problem. Because folding fans are made of paper and bamboo and held in the hand, old traditional folding fans are more or less damaged; for example, many culturally valuable folding fans have lost their bones and have damaged edges, have been stretched flat, and have been framed like paintings. Reproducing the original fan without information of the original form is difficult. In the present study, we provide a digital fan model for examining the original fan shape. Old valuable folding fans are treasured by museums and collectors around the world. In future research, we would like to capture such precious folding fans in three-dimensional space applying our digital fan model and to exhibit these fans in a digital museum, providing opportunities not only to enjoy the value of the fans but also to encourage the research of Japanese traditional culture.


Philosophy ◽  
1982 ◽  
Vol 57 (221) ◽  
pp. 339-355 ◽  
Author(s):  
Roderick Millar

It is commonly believed that there are, in the world, large numbers of objects which occupy three-dimensional space. It is also commonly believed that at least a large part of people's experience is of the surfaces of these material objects. Nevertheless, arguments have been adduced in favour of the view that we are never aware of such surfaces but only of distinct items called ‘sense-data’. It has also been suggested that if we couple the view that experience is limited to sense-data with an empiricist thesis to the effect that knowledge is limited by experience then we are forced to the conclusion that we cannot have any knowledge of material objects. There have been many attempts to reconcile the sense-data thesis with common beliefs about material objects. Among them have been representative realism and phenomenalism. However, a view which may have found favour recently is the Quinean one that ‘the myth of physical objects is epistemologically superior to most in that it has proved more efficacious than other myths as a device for working a manageable structure into the flux of experience’.1


2003 ◽  
Vol 31 (2) ◽  
pp. 533-546
Author(s):  
Stepan Davtian ◽  
Tatyana Chernigovskaya

Diagnostics of a mental disorder completely bases on an estimation of patient’s behaviour, verbal behaviour being the most important. The behaviour, in turn, is ruled by a situation expressed as a system of signs. Perception of a situation could be seen as a function, which depends on the context resulting from the previous situations, structuring personal world. So the world is not given — it is being formed while the person is in action. We argue that distinctive features of behaviour, including its abnormal variants, can be explained not in categories of characters and diseases but in terms of situations taking place in individual worlds. The situation in which a person perceives himself is not simply a site in a three-dimensional space at a certain moment, but a part of the world and an episode of his life. Like a text composed of words, individual world is composed of situations. Each of them needs certain context to cope with ambiguity. This context is induced by the world as a whole. And the world, in turn, is presented as a chain of situations. If the context cannot help to interpret a situation adequately, uncertainty can be eliminated by actions clarifying a situation, which is changed in a predictable way. Thus, purposeful activity, skills to make predictions and corrections of one’s own actions are crucial. Weakness of any of them inevitably leads to the distortion of the presentation of the world, to wrong evaluation of situations and, as a result, to inadequate actions that finally reduce the activity as being ineffective. Thus, the lack of activity becomes the key factor in the development of disorder, being simultaneously its cause and effect. In periods of insufficient activity conditions for violated (and violating) sign processing arise. Possible variants of sign malfunction are: oligosemia (reduction of the number of perceivable signs), hyposemia (decrease of significance of signs), hypersemia (increase of significance of some signs at the expense of others), ambisemia (uncertainty of sign, when situation remains unclear), cryptosemia (recognition of signs not obvious for other observers), and parasemia (perverted interpretation of signs influenced by a false context).


Author(s):  
Dale Purves

Perceived motion is defined as the apparent speed and direction of objects that are translating and/or rotating in three-dimensional space. It has long been clear, however, that the perceived speeds and directions of moving objects disagree with physical measurements of motion. With respect to speed, the flash-lag effect has been a major focus; with respect to direction, the emphasis has been on the effects of apertures. These phenomena—and many others—raise the question of how we routinely succeed in the world despite blatant discrepancies between the motions we see and the physical speeds and directions of the objects we must deal with. Resolving this puzzle presents another body of evidence pertinent to whether empirical ranking is the way nervous systems link objective and subjective domains.


Author(s):  
Zoya O. Vyzhva

The estimator of the mean-square approximation of 3-D homogeneous and isotropic random field is investigated. The problem of statistical simulation of realizations of random fields in threedimensional space is considered. The algorithm for the receiving of this realization has been formulated, which has been constructed on the base the mean-square approximation of random fields estimator. It has been constructed the statistical model for the Gaussian random fields in three-dimensional space, which has been given by its statistical characteristics.


2001 ◽  
Vol 24 (4) ◽  
pp. 581-601 ◽  
Author(s):  
Roger N. Shepard

The universality, invariance, and elegance of principles governing the universe may be reflected in principles of the minds that have evolved in that universe – provided that the mental principles are formulated with respect to the abstract spaces appropriate for the representation of biologically significant objects and their properties. (1) Positions and motions of objects conserve their shapes in the geometrically fullest and simplest way when represented as points and connecting geodesic paths in the six-dimensional manifold jointly determined by the Euclidean group of three-dimensional space and the symmetry group of each object. (2) Colors of objects attain constancy when represented as points in a three-dimensional vector space in which each variation in natural illumination is canceled by application of its inverse from the three-dimensional linear group of terrestrial transformations of the invariant solar source. (3) Kinds of objects support optimal generalization and categorization when represented, in an evolutionarily-shaped space of possible objects, as connected regions with associated weights determined by Bayesian revision of maximum-entropy priors.


Fractals ◽  
1993 ◽  
Vol 01 (04) ◽  
pp. 875-880 ◽  
Author(s):  
ADAM GADOMSKI ◽  
JERZY LUCZKA

A continuous random walk of a growing cluster of dimension df is studied. It is assumed that its behavior is represented by a standard diffusion equation. A diffusion coefficient is assumed to be a cluster mass dependent power function which in the dilute solution regime takes a form first suggested by Kirkwood. The mass of the cluster increases in time according to another power law. It results in anomalous diffusion of the cluster in a three dimensional space which, in a linear case, is manifested by either power or logarithmic law of the mean square displacement. Some interesting examples and realizations of that process in polymer science, colloid physicochemistry or materials science are pointed out.


2011 ◽  
Vol 8 (2) ◽  
pp. 79-88
Author(s):  
Mirna Radin Sabadoš

The proposal that the world is made of sequences of zeros and ones, overtly expressed in DeLillo’s early novel Ratner’s Star (1976), marks the first time in DeLillo’s fiction that he introduces the idea that the (creation of) reality is of mathematical nature. The “zero-oneness” of the world thirty odd years later, although it still may be an uncommon thought in literature, is ubiquitous in the visual arts, in film and in architecture, and binary code has become the basis of our digitally enhanced reality. Looking at DeLillo’s Millennial novels, this paper seeks to explore models of the space-time continuum of the fictional reality that DeLillo constructs; focusing on Ratner’s Star as a literary exploration of a three-dimensional space and on the novel Body Artist as an investigation of the fourth dimension, pondering time, we hope to register the “sum total of one’s data” (WN) as the only palpable texture of DeLillo’s reality.


1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.


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