Graphic Devices Research Articles

How Focus of Interest in Pictures Changes with Age: A Cross-cultural Comparison

British and Chinese participants ranging from 4 years of age to adult were presented with sets of drawings of everyday objects, and asked to match two out of three. The drawings could be matched on colour, subject matter, or visual metaphor. In both cultures there was a significant progression from matching on colour to subject matter, and then from matching on subject matter to metaphor. These age-related differences in the selected basis for matching may reflect age-related changes in focus of interest, and provide experimental data that is consistent with Parsons’ (1987) claims towards the development of understanding about art. The findings of broadly similar age differences in Chinese as well as British children suggest that this pattern of development is not culture-specific. Chinese children, however, showed an earlier and more pronounced progression to matching on metaphor than did the British children, which is hard to reconcile with previous suggestions (see, for example, Parsons, 1987; Winner, 1989) that a progression of interest beyond subject matter may not take place in Eastern cultures. The training Chinese children receive in monitoring detail in pictures and in Chinese characters may facilitate attention to the graphic devices that communicate metaphorical messages.

General Techniques for Evaluating Twistor Diagrams

Explicit differential and integral relationsthat afford a natural basis for systematicallyevaluating twistor diagrams are presented. Theevaluation techniques include making use of aconformally invariant parametrization prescription along with a setof graphical computational devices which clearly bringout the striking features of the integrals associatedwith such diagrams. It appears that the main results of the relevant calculations carried outearlier can all be extracted from structures which ariseout of effectively implementing the techniques. Both thetopological character and the location of the contours presumably borne by any diagrams turn out to bespecified in a unique way. Another explanation of thebreaking of the conformal symmetry that arises in thecontext of twistor theory is automaticallyprovided.

Paramagnetically induced nuclear magnetic resonance relaxation in solutions containing S⩾1 ions: A molecular-frame theoretical and physical model

The enhancement of nuclear magnetic resonance (NMR) relaxation rates produced by paramagnetic solutes is physically rather different for electron spin S=1/2 paramagnetic species than for S⩾1 species due to the presence of zero-field splitting interactions in the electron spin Hamiltonians of the latter. When the zfs energy is larger than the electronic Zeeman energy, the electron spin precessional motion is spatially quantized with respect to the molecule-fixed principal axis system (PAS) of the zfs tensor rather than along the external laboratory magnetic field. An analytical theory of the orthorhombic zfs limit has been derived in which the motion of the electron spin variables is described in the zfs-PAS and that of the nuclear spin variables in the laboratory coordinate frame. The resulting theoretical expressions are simple in form and suggest a physically transparent interpretation of the experiment. The NMR relaxation enhancement R1p results from additive contributions, R1x, R1y, and R1z, arising from the molecular-frame Cartesian components of the time-dependent electron spin magnetic moment operator μr(t). Each Cartesian component R1r depends on the dipolar power density at the nuclear Larmor frequency that is produced by the corresponding Cartesian component of μr(t). The theory displays the dependence of the relaxation enhancement on the variables of molecular structure in a very simple and physically transparent form: R1r∝r−6[1+P2(cos θr)], where r is the interspin distance and cos θr is the direction cosine of the interspin vector with the rth principal axis of the zfs tensor. New experimental data are presented for the model S=1 complex [trans-Ni(II)(acac)2(H2O)2] (acac=acetylacetonato) in dioxane solvent. The magnetic field dependence of the proton T1 of the axial water ligands has been measured over the range 0.15–1.5 T, the lower end of which corresponds to the zfs limit. The experimental data have been analyzed using the new analytical theory for the zfs-limit regime in conjunction with spin dynamics simulations in the intermediate regime. Dipolar density power plots are presented as graphical devices which clearly exhibit the physical information in the experiment, and which permit a rapid differentiation of the sensitive and insensitive parameters of theory. The data analysis depends strongly on the zfs parameter |E| and on the electron spin relaxation time τS,z along the zfs-PAS z-axis, but only very weakly on the other parameters of theory. A fit of the data to theory provided the values |E|=1.8±0.1 cm−1 and τS,z=8.0±0.3 ps.

非線形手法と行動計量学

We are now observing quick and vast development of new non-linear methods for data analysis such as chaos and neural network in various scientific research fields. Those methods are also regarded as basic tools for the analysis in a still vaguely-defined research area called“complexity”It can be said that the development of such non-linear methodologies is no doubt inspired by recent rapid progress of high-speed computing facilities and graphical representation devices. The aim of the present article is two-fold. The first is to give a review of some recent development of chaos and artificial neural network(ANN)from a statistical viewpoint. Fundamental ideas and main features of chaos and ANN are shown with some illustrations of computer simulation. The second thing is, on the basis of past development of such methodologies, to mention some research topics which would be carried out near future in behaviormetrics and also in statistics, although such collection is of the author's personal view. In bibliography given at the end of the present article, research articles and review papers concerning non-linear methods appeared in main statistical journals after 1990 were collected and shown with short comments. Publications upon“complexity”for academic as well as for general readers are also listed. The list would be helpful for the reader to understand the basic idea of complexity and also to proceed his/her own research as well.

Torsional diplopia and its perceptual consequences: A 'user-friendly' test for oblique eye muscle palsies

Purpose: (1) To present a simple clinical test of torsional diplopia, based on the observation that a person with acquired incomitant cyclotorsion will perceive nonparallel double images of a horizontal rod held before the eyes. The apparent image crossing will determine laterality. (2) To study changes in visual perception induced by cyclotorsion. Methods: Ten subjects with unilateral or bilateral fourth nerve palsy and one subject with isolated superior branch third nerve palsy were studied. Simulation of image displacement in cyclotorsion with a computer graphic device was performed on three normal subjects to analyze the perceptual consequences of torsional diplopia. Results: In cyclotorsion, displacement of the retinal image could be separated into two vectors, each parallel to the eye's main meridians. Vertical displacement led to vertical diplopia because of the small fusional amplitude for vertical disparity, while fusion of the horizontally displaced retinal image was often possible. This led to changes in depth perception. Cyclotorsion, therefore, induces complex perceptual changes. These changes could be simulated in the laboratory in normal subjects. Conclusions: Cyclotropia acquired after childhood usually produces torsional diplopia. The subjective horizontal rod test is a convenient way of analyzing such misalignment. Visual disturbances in cyclotorsion are more complex than has previously been appreciated.

Australia

This overview of computer graphics education in Australia offers a few surprises in the diversity demonstrated by university curricula, and the languages and hardware used. Computer graphics is taught as a third year course at most Australian universities, with some universities also offering an additional advanced graphics course at the fourth year level.Most universities include what has evolved into a set of core topics that are common to most graphics courses. Most have also added some extra flavor to their courses by providing some unique topics that, although vaguely related, are not normally considered under the heading of mainstream graphics.Each curriculum generally includes all the expected graphics topics, such as line and curve generation, antialiasing, 2D transformations, 3D transformations and 3D viewing, hidden line and hidden surface algorithms, polygon fill algorithms, clipping, illumination and shading models and solid modeling. A good proportion of universities also include texture mapping, color modeling (e.g., RGB and CIE representations), animation, virtual/synthetic camera modeling, GUI design, splines and Bezier surfaces, fractals, ray tracing and human visual perception. Less commonly offered topics are dithering, radiosity and mathematical models.Approximately half of the courses are centered around device independent graphics standards such as GKS and PHIGS, and the SRGP software package is popular in courses based on the PHIGS standard The core topics in these graphics standards courses include graphical input techniques, graphical display devices for output, coordinate systems (world, virtual, and device), graphics primitives, windows and viewports and metagraphics commands.

A Portfolio Approach to Strategic Hospital Analysis

Hospital planners rely on a number of graphic and quantitative devices to facilitate hospital strategic planning and each has its place. It is the comprehensive, user-friendly, environmental assessment models that are missing, however. This article seeks to remedy this condition through the introduction of a portfolio approach to strategic analysis. The authors review the analytical tools currently used by hospital planners to place this model in context and provide an exposition of the model and an explanation of how it is constructed and interpreted.

A Portfolio Approach to Strategic Hospital Analysis: Exposition and Explanation

Hospital planners rely on a number of graphic and quantitative devices to facilitate hospital strategic planning and each has its place. It is the comprehensive, user-friendly, environmental assessment models that are missing, however. This article seeks to remedy this condition through the introduction of a portfolio approach to strategic analysis. The authors review the analytical tools currently used by hospital planners to place this model in context and provide an exposition of the model and an explanation of how it is constructed and interpreted.

The Early Use and Development of Graphic Formulas: Two Case Study Reports of Graphic Formula Production by 2- to 3-year-old Children

Graphic formulas are an important denotational device in the drawing repertoires of adults and school-age children. They provide a stable basis for working out, modifying, and elaborating various aspects of graphicrepresentation. As such, they might also serve as useful graphic devices for very young children who are just beginning to use drawing as a representational medium. However, there are very few studies which have examined graphic formula production in the earliest phases of drawing. The case study reports presented here focus on the use and elaboration of graphic formulas by two 2to 3-year-old children. They provide strong evidence, first, that graphic formulas are indeed available to even very young children. Secondly, they provide insight into the developmental processes by which the elaboration and reorganisation of graphic formulas occurs.

C program for automatic contouring of spherical orientation data using a modified Kamb method

Kamb's method for contouring density diagrams is a simple technique for the preliminary analysis and comparison of orientation data distributions. The method is based on the departure from a uniform distribution, and, unlike the Schmidt method, the dependence of contours on sample size is limited. Several improvements can be made, particularly with regard to the implementation of automatic contouring. To reduce smoothing, the expected count for a random sample drawn from a uniform distribution can be decreased. This gives more localized density estimates that can improve the resolution of features. Density estimates are done directly on the sphere for accuracy. This also permits contouring on stereographic and other nonequal area projections, and accommodates vectorial data. Weighting functions provide better density estimates and increase the smoothness of contour lines. These concepts are implemented in the C program Sphere Contour. Options include selection of data rotation, linear or planar data, equal area or stereographic projection, upper or lower hemisphere, and scatter diagrams. Graphics output is either to the screen (MS-DOS) or to a computer-aided drafting file (AutoCAD DXF). The program is modified easily for other computer systems and graphics devices.

Visualization of Mathematical Surfaces: the IZIC Server Approach

This paper presents IZIC, a stand-alone high-quality 3D graphic tool driven by a command language. IZIC is an interactive version of ZICLIB , a 3D graphic library allowing efficient curve and surface manipulations using a virtual graphic device. Capabilities of ZICLIB include management of pseudo or true colors, illumination model, shading, transparency, etc. As an interactive tool, IZIC is run as a Unix server which can be driven from one or more computer algebra systems, including Maple, Mathematica, Macsyma, and Reduce, or through an integrated user interface such as CAS/PI. Connecting IZIC with a different system is a very simple task which can be achieved at run-time and requires no compilation. Also important is the possibility to drive IZIC both through its freely-reconfigurable menu-button user interface, and through its command language. This brings a high level of programmability and interoperability, allowing, for instance, the remote animation of surfaces from the symbolic computation engine.

Fast polygon scan conversion with medical applications

The algorithm presented for polygon scan conversion is very fast and can replace the standard version in any application. Special requirements from medical data sets illustrate its practicality and versatility. The polygon scan conversion problem refers to filling the interior of a region represented by one or more polygons. The polygons are represented by the coordinates of their vertices in cyclic order. This problem shows up in many areas of computer graphics. The standard approach to polygon scan conversion creates two data structures, an edge table and an active edge table (AET). The edge table contains a bucket for each scan line. Each bucket consists of a linked list containing all the edges starting on that scan line (or straddling it for the first time). Creation of the edge table is an image-space step, since it depends on the number of scan lines existing in image space (that is, on the resolution of the target display device). In this respect, it is a device-dependent step. The algorithm we develop uses only an object-space data structure instead of the edge table and is therefore less device dependent. In particular, it is suitable for both raster and vector graphics devices.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Modeling the relationship between source code complexity and maintenance difficulty

Canonical correlation analysis can be a useful exploratory tool for software engineers who want to understand relationships that are not directly observable and who are interested in understanding influences affecting past development efforts. These influences could also affect current development efforts. In this paper, we restrict our findings to one particular development effort. We do not imply that either the weights or the loadings of the relations generalize to all software development efforts. Such generalization is untenable, since the model omitted many important influences on maintenance difficulty. Much work remains to specify subsets of indicators and development efforts for which the technique becomes useful as a predictive tool. Canonical correlation analysis is explained as a restricted form of soft modeling. We chose this approach not only because the terminology and graphical devices of soft modeling allow straightforward high-level explanations, but also because we are interested in the general method. The general method allows models involving many latent variables having interdependencies. It is intended for modeling complex interdisciplinary systems having many variables and little established theory. Further, it incorporates parameter estimation techniques relying on no distributional assumptions. Future research will focus on developing general soft models of the software development process for both exploratory analysis and prediction of future performance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An adaptive enhancement algorithm for quantized images

When high-quality images are displayed by low-level graphics devices, they must be re-quantized. Many quantization algorithms have been proposed to solve this problem. However, the fine details cannot manifest themselves in the quantized images by the general quantization algorithms. In this paper, an adaptive technique is proposed to enhance the quantized images such that the fine features such as edges, thin lines, and curves are more visible. By tuning a threshold value, the desired patterns used to produce the visual impression of grayscale information at constant and small varying areas can be preserved and the high frequency information can made more visible.

Analysis of the Structure and Resolution of a Graphics Device

Analysis of the Structure and Resolution of a Graphics Device

Domain expertise and knowledge acquisition from “nonlinear” expository text

This article examines some important theoretical issues with regard to how nonlinear text structures of the kind embodied in hypertext might affect learning. Empirical results showing that well-structured nonlinear texts are as effective as conventional linear ones for learning factual information and that they can enhance inferential reasoning are presented and discussed. It is suggested that using a graphic device called a “conceptual map” to represent the relationships between text concepts can help the reader form a coherent view of the textual information and constrain nonlinear reading to useful juxtapositions of text units.

On generating topologically consistent isosurfaces from uniform samples

A set of sample points of a function of three variables may be visualized by defining an interpolating functionf of the samples and examining isosurfaces of the formf(x, y, z)=t for various values oft. To display the isosurfaces on a graphics device, it is desirable to approximate them with piecewise triangular surfaces that (a) are geometrically good approximations, (b) are topologically consistent, and (c) consist of a small number of triangles. By topologically consistent we mean that the topology of the piecewise triangular surface matches that of the surfacef(x, y, z)=t, i.e., the interpolantf determines both the geometry and the topology of the piecewise triangular surface. In this paper we provide an efficient algorithm for the case in whichf is the piecewise trilinear interpolant; for this case existing methods fail to satisfy all three of the above conditions simultaneously.

A system for approximate tree matching

Ordered, labeled trees are trees in which each node has a label and the left-to-right order of its children (if it has any) is fixed. Such trees have many applications in vision, pattern recognition, molecular biology, programming compilation, and natural language processing. Many of the applications involve comparing trees or retrieving/extracting information from a repository of trees. Examples include classification of unknown patterns, analysis of newly sequenced RNA structures, semantic taxonomy for dictionary definitions, generation of interpreters for nonprocedural programming languages, and automatic error recovery and correction for programming languages. Previous systems use exact matching (or generalized regular expression matching) for tree comparison. This paper presents a system, called approximate-tree-by-example (ATBE), which allows inexact matching of trees. The ATBE system interacts with the user through a simple but powerful query language; graphical devices are provided to facilitate inputing the queries. The paper describes the architecture of ATBE, illustrates its use and describes some aspects of ATBE implementation. We also discuss the underlying algorithms and provide some sample applications.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Knowledge-Based Protein Modeling

Knowledge, both from the three-dimensional structures of homologous proteins and from the general analysis of protein structure, is of value in modeling a protein of known sequence but unknown structure. While many models are still constructed at least in part by manual methods on graphics devices, automated procedures have come into greater use. These procedures include those that assemble fragments of structure from other known structures and those that derive coordinates for the model from the satisfaction of restraints placed on atomic positions.

Infographics Today: Using Qualitative Devices to Display Quantitative Information

Creative vision has been joined by technological capability to generate a surge in the number and variety of graphic devices on newspaper pages. And this has been accompanied by an expansion in the role of graphic departments.