bluuebunny/crossref_metadata_2025 huggingface dataset:
Advantage Amnesia
Authors: Andal Angela A. , Yip George S.
Published: March 2003

The dot‐com crash exposed a business phenomenon ‐ “advantage amnesia”, the state of becoming entangled in the Internet stampede at the expense of the basics of competitive advantage. It led many managers to lose sight of how to leverage their traditional competitive advantages in order to gain new‐economy success. But now we can refresh our memories.
Cross‐Modal Transfer of Shape is Difficult to Demonstrate in One‐Month‐Olds
Authors: Maurer Daphne , Stager Christine L. , Mondloch Catherine J.
Published: March 2003

We tested 1‐month‐olds for cross‐modal transfer of shape between touch and vision using a procedure described by Meltzoff and Borton, but including controls for side bias and stimulus preference. In Experiment 1 (N = 48), infants' looking times to smooth and nubby visual stimuli were not influenced by previous oral exposure to one of the shapes during the preceding 90 s, except for an effect on the first test trial in one group; this effect could have been due to limited cross‐modal transfer, to Type 1 error, or to side bias, possibly interacting with a small stimulus preference. The failure of that effect to replicate in a group (N = 16) with less side bias (Experiment 2) suggests that it was not due to cross‐modal transfer. Experiment 3 (N = 32), an exact replication of Meltzoff and Borton's experiment, also failed to yield evidence of cross‐modal transfer. Overall, there is not good evidence that 1‐month‐olds can transfer information about these shapes from touch to vision. Future studies exploring the ability to transfer information about other shapes will be easier to interpret if they include controls for side bias and stimulus preference.
The Impact of Children's Static versus Dynamic Conceptions of People on Stereotype Formation
Authors: Levy Sheri R. , Dweck Carol S.
Published: March 2003

Recent cognitive‐developmental research has contributed much to our understanding of children's stereotyping. The present research identified another factor influencing stereotyping — children's theories about the malleability of human attributes. In two studies, 122 sixth graders learned about several different students' behaviors in unknown schools. In Study 1, they judged a school characterized by mostly negative behaviors, and in Study 2 they judged two schools (characterized by either mostly negative or positive behaviors). Across studies, children with a fixed view of personality (relative to those with a more malleable view of personality) made more extreme trait ratings of both the “positive” and “negative” schools, generalized their trait judgments to an unknown student, perceived greater within‐school similarity and between‐school differences, and showed less desire to interact with students in the “negative” school. Ways in which examining these theories may broaden our understanding of the origins of stereotyping and how to lessen it are discussed.
Relations between Drawing Cubes and Copying Line Diagrams of Cubes in 7‐ to 10‐Year‐Old Children
Authors: Bremner J. Gavin , Morse Rachel , Hughes Sara , Andreasen Gillian
Published: March 2003

Previous research has suggested both links and differences between children's copying of line diagrams and their drawings of solid objects. If the diagram represents a familiar object, children make more errors than when copying a diagram of a nonobject or unfamiliar object, as if they are drawing from their representation of the object rather than copying the surface features of the diagram. However, copying a diagram yields fewer and different types of errors than drawing the equivalent solid, which suggests a different process. In Experiment 1 (n= possible relations between copying and drawing are investigated by asking children to draw a solid cube, then to copy or trace a line diagram of the cube in oblique projection, and finally to draw the solid again. Copying was better than drawing, and there was positive transfer to a subsequent drawing. Tracing was very accurate, but transfer to drawing did not occur, possibly because of the automatic nature of tracing. In Experiment 2 (n= different groups received versions of the copying task that differed in the extent to which temporal order of line copying was structured. Asking children to copy the lines in a systematic order led to improved copies, but this performance did not carry over to a subsequent drawing of the solid. In contrast, when temporal ordering of line copying was not manipulated, there was positive transfer from copying to the subsequent drawing. In Experiment 3 (n= 80), provision of structure that emphasized faces by color‐groupings of lines or coloring faces led to improved copies and did not hinder transfer to drawing the solid. Experiment 4 (n= 90) showed that in a solid drawing task emphasis on faces but not edges produced a positive effect, both on the immediate drawing and on a subsequent drawing of a plain cube. We conclude that emphasis on order of line copying improves performance in a copying task because in that case line‐to‐line matching is an important element of the skill, whereas this does not aid drawing of the solid object, in which the focus is primarily on representation of faces and their interrelations.
Parenting among Low‐Income, African American Single Mothers with Preschool‐Age Children: Patterns, Predictors, and Developmental Correlates
Authors: McGroder Sharon M.
Published: March 2003

Dimensions and patterns of parenting were examined in a sample of 193 low‐income African American single mothers with preschool‐age children. Factor analyses yielded three dimensions: Aggravation, Nurturance, and Cognitive Stimulation. Cluster analysis yielded four patterns of parenting: Aggravated but Nurturant; Cognitively Stimulating; Patient and Nurturant; and Low Nurturance. Discriminant function analysis was used to predict membership in each of the four parenting clusters. Two composite functions emerged, the first representing maternal well‐being (locus of control, depressive symptoms), the second representing sociodemographic characteristics (maternal education, duration on welfare, age at first birth), accounting for 93% of between‐groups variability. Children's scores on measures of cognitive school readiness and personal maturity were significantly related to parenting pattern, even after controlling for significant predictors of parenting pattern; children's verbal ability was no longer related to parenting pattern once significant maternal characteristics were controlled. Findings are discussed in terms of contributions to the literature on parenting and in terms of implications for welfare policy and programs.
The Cues That Infants Use to Distinguish Discontinuous Quantities: Evidence Using a Shift‐Rate Recovery Paradigm
Authors: Tan Lynne S. C. , Bryant Peter
Published: March 2003

A novel experimental method, shift‐rate recovery, was developed and used in a series of three experiments. These examined the extent to which 6‐month‐old infants (N= 131) find perceptual cues such as density and length useful in the discrimination of linearly arranged sets containing large numbers of objects. Results showed that infants discriminated between arrays that differ in number and density, with length held constant, when the arrays were presented either simultaneously or successively. On the other hand, infants discriminated only between arrays that differ in number and length, with density held constant, when the arrays were presented simultaneously. Infants were, however, able to perform a successive length discrimination when the arrays were continuous rather than consisting of discrete items. These findings support the conclusion that infants are able to discriminate between large number sets by relying on absolute cues such as density (but not length) and on relative cues such as optical one‐to‐one correspondence.
The Vicissitudes of Measurement: A Confirmatory Factor Analysis of the Emotional Autonomy Scale
Authors: Schmitz Mark F. , Baer Judith C.
Published: March 2003

This study examined the factor structure of the Emotional Autonomy Scale (EAS) as proposed by Steinberg and Silverberg. Participants were from three independent samples of adolescents in grades 6 (n = 1,842), 8 (n = 1,769), and 10 (n = 1,232), with each sample consisting of three ethnic groups: African American, European American, and Mexican American. None of the confirmatory factor analyses for these samples supported the factor structure proposed by Steinberg and Silverberg. From the three models tested, the EAS is best described by the four originally proposed factors, combined with two method factors, one consisting of the positively worded scale items and one consisting of the negatively worded scale items. Results show that the EAS exhibits poor construct validity and behaves quite differently for the different grade and ethnic groups. The strong impact of method variance on the factor structure is discussed. Although various alternative solutions to the psychometric problems in the EAS are proposed, the most credible solution may be to reexamine the conceptual foundations of emotional autonomy and develop better measures of those concepts for adolescents.
You Go This Way and I’ll Go That Way: Developmental Changes in Infants’ Detection of Correlations among Static and Dynamic Features in Motion Events
Authors: Rakison David H. , Poulin‐Dubois Diane
Published: March 2003

Four experiments utilizing the habituation procedure examined 10‐ to 18‐month‐olds’ ability to detect and encode correlations among features in a motion event (N= 136). Infants were habituated to two events in which objects—with distinct parts and a distinct body—moved across a screen along a rectilinear or curvilinear motion path. Infants were then tested with one familiar event and three events in which one feature of the object (parts, body, or motion path) was presented in a novel combination with the other features. The results of the experiments revealed that 10‐month‐olds process independently static features in an event, but do not process correlations among dynamic features; whereas 14‐month‐olds detect the correlation between an object's parts and its motion trajectory, but only when the movement of parts is correlated with the motion of the object. Further, the data show that 18‐month‐olds detect correlations between all three features when the parts of the object move, but they detect only the relation between parts and motion path when the parts do not move. It is proposed that infants develop representations for the static and dynamic properties of objects through a sensitive perceptual system that detects individual features, whole objects, and movement properties, and a domain‐general associative learning mechanism that encodes independent features and correlations among features.
Maternal Employment and Child Cognitive Outcomes in the First Three Years of Life: The NICHD Study of Early Child Care
Authors: Brooks–Gunn Jeanne , Han Wen–Jui , Waldfogel Jane
Published: March 2003

With increased numbers of women employed in their children’s first year of life and with increased attention being paid by parents and policy makers to the importance of early experiences for children, establishing the links that might exist between early maternal employment and child cognitive outcomes is more important than ever. Negative associations between maternal employment during the first year of life and children’s cognitive outcomes at age 3 (and later ages) have been reported using data from the National Longitudinal Survey of Youth–Child Supplement. However, it was not known whether these findings would be replicated in another study, nor whether these results were due to features of child care (e.g., quality, type), home environment (e.g., provision of learning), and/or parenting (e.g., sensitivity). This study explored these issues using data on 900 European American children from the National Institute of Child Health and Human Development Study of Early Child Care, which provides information on child cognitive scores at 15, 24, and 36 months, as well as data about the home environment (as assessed by the Home Observation of the Measurement of the Environment Scale), parental sensitivity, and child–care quality and type over the first 3 years of life. Maternal employment by the ninth month was found to be linked to lower Bracken School Readiness scores at 36 months, with the effects more pronounced when mothers were working 30 hr or more per week and with effects more pronounced for certain subgroups (i.e., children whose mothers were not sensitive, boys, and children with married parents). Although quality of child care, home environment, and maternal sensitivity also mattered, the negative effects of working 30 hr or more per week in the first 9 months were still found, even when controlling for child–care quality, the quality of the home environment, and maternal sensitivity. Implications for policy are also discussed.
Control and Cross‐Domain Mental Computation: Evidence from Language Breakdown
Authors: Frawley William
Published: March 2003

This paper uses the notion of control from programming languages to look at the organization of mental code. Data for the analysis comes principally from language breakdown. The paper first outlines the well known distinction between logic and control in algorithms and argues that the same distinction holds in mental code. Discussion then focuses mainly on control—the management of data flow—and shows that a variety of language disorders affect either the logic component of the mental algorithms for language (e.g., Specific Language Impairment) or the control component (e.g., Williams syndrome and Turner syndrome). A comparative study of the loss of morphology in Williams syndrome and Specific Language Impairment reinforces the logic/control split as an accurate guide to the explanation of linguistic behavior in these disorders. The data, moreover, are not accountable to sheer performance factors, but to the way the disorders disrupt the structure of mental algorithms. The paper closes with a discussion of how control and the management of cross‐domain computation fit into recent theories of modular mental architecture and proposals about the explicitness of representations and their availability to working memory.
Topological Spatio–Temporal Reasoning and Representation
Authors: Muller Philippe
Published: March 2003

We present here a theory of motion from a topological point of view, in a symbolic perspective. Taking space–time histories of objects as primitive entities, we introduce temporal and topological relations on the thus defined space–time to characterize classes of spatial changes. The theory thus accounts for qualitative spatial information, dealing with underspecified, symbolic information when accurate data are not available or unnecessary. We show that these structures give a basis for commonsense spatio–temporal reasoning by presenting a number of significant deductions in the theory. This can serve as a formal basis for languages describing motion events in a qualitative way.
Agent Reasoning Mechanism for Long–Term Coalitions Based on Decision Making and Trust
Authors: Vassileva Julita , Breban Silvia , Horsch Michael
Published: March 2003

We address long–term coalitions that are formed of both customer and vendor agents. We present a coalition formation mechanism designed at the agent level as a decision problem. The proposed mechanism is analyzed at both system and agent levels. Our results show that the coalition formation mechanism is beneficial for both the system—it reaches an equilibrium state—and for the agents—their gains highly increase over time.
Architectural Components of Information–Sharing Societies
Authors: Carter Jonathan , Ghorbani Ali A. , Marsh Stephen
Published: March 2003

Two similar multi–agent systems have been designed to address the issue of information sharing within a multi–agent system. This paper examines the architectural components that have been added to our information–sharing societies, ACORN and MP3. Through this exploration, we conclude that these components and their underlying concepts can be added to other information–retrieval societies.

ACORN consists of a set of information–sharing locations referred to as cafés. Cafés are defined as meeting locations for like–minded agents. Like–minded agents are defined as agents that share a common set of interests. As an example, a café may contain agents that are interested in information relating to cars. A dynamic café clustering method is developed. The performance evaluation of the proposed structure for the café is presented. The concept of a fat/thin agent architecture is introduced. This agent architecture allows for minimizing network traffic as agents traverse the network in search of or distribution of knowledge. The directory server component is presented along with its relation to the fat/thin agent architecture. Finally, an anonymity service provider which allows anonymity for users is introduced.

The MP3 society exists with the sole purpose of finding MP3s throughout a given network. Through this society, the core design issues of agent verification and agent validation are addressed and solutions are presented through respective interface components.
Surface Reconstruction Using Alpha Shapes
Authors: Guo Baining , Menon Jai , Willette Brian
Published: March 2003

We describe a method for reconstructing an unknown surface from a set of data points. The basic approach is to extract the surface as a polygon mesh from an α‐shape. Even though alpha shapes are generalized polytopes having complicated internal structures, we show that manifold surfaces, with or without boundaries, can be efficiently generated, and these surfaces completely describe the α‐shapes to the extent that they are visible from outside. Unlike the original α‐shapes, the polygonal surfaces can be easily simplified to yield compact models suitable for a variety of geometric modeling applications such as surface fitting.
An Algorithm for Dynamic Color Management
Authors: Fischer Martin
Published: March 2003

Though the problem of color quantization in static images is not completely solved, there are a few algorithms that produce good results. Color quantization with dynamic color requests is an unsolved problem. In this paper we present an algorithm that manages dynamic color allocations without advance knowledge of the sequence of color requests. It uses a dynamic color table that can be used simultaneously in multiple windows from one or more applications. Advance knowledge about color requirements will improve the results of the algorithm.
A Modelling Method and User Interface for Creating Plants
Authors: Lintermann Bernd , Deussen Oliver
Published: March 2003

We present a modelling method and graphical user interface for the creation of natural branching structures such as plants. Structural and geometric information is encapsulated in objects that are combined to form a description of the model. The model is represented graphically as a structure graph and can be edited interactively. Global and partial constraint techniques are integrated on the basis of tropisms, free‐form deformations and pruning operations to allow the modelling of specific shapes. We show examples to illustrate the design process and evaluate the user interface.
A Bernstein‐Bézier Based Approach to Soft Tissue Simulation
Authors: Roth S.H. , Gross Markus H. , Turello Silvio , Carls Friedrich R.
Published: March 2003

This paper discusses a Finite Element approach for volumetric soft tissue modeling in the context of facial surgery simulation. We elaborate on the underlying physics and address some computational aspects of the finite element discretization.

In contrast to existing approaches speed is not our first concern, but we strive for the highest possible accuracy of simulation. We therefore propose an extension of linear elasticity towards incompressibility and nonlinear material behavior, in order to describe the complex properties of human soft tissue more accurately. Furthermore, we incorporate higher order interpolation functions using a Bernstein‐Bézier formulation, which has various advantageous properties, such as its integral polynomial form of arbitrary degree, efficient subdivision schemes, and suitability for geometric modeling and rendering. In addition, the use of tetrahedral Finite Elements does not put any restriction on the geometry of the simulated volumes.

Experimental results obtained from a synthetic block of soft tissue and from the Visible Human Data Set illustrate the performance of the envisioned model.
Programming Paradigms in an Object‐Oriented Multimedia Standard
Authors: Duke D. J. , Herman I.
Published: March 2003

Of the various programming paradigms in use today, object‐orientation is probably the most successful in terms of industrial take‐up and application, particularly in the field of multimedia. It is therefore unsurprising that this technology has been adopted by ISO/IEC JTC1/SC24 as the foundation for a forthcoming International Standard for Multimedia, called PREMO. Two important design aims of PREMO are that it be distributable, and that it provides a set of media‐related services that can be extended in a disciplined way to support the needs of future applications and problem domains. While key aspects of the object‐oriented paradigm provide a sound technical basis for achieving these aims, the need to balance extensibility and a high‐level programming interface against the realities of efficiency and ease of implementation in a distributed setting meant that the task of synthesising a Standard from existing practice was non‐trivial. Indeed, in order to meet the design aims of PREMO is was found necessary to augment the basic object infrastructure with facilities and ideas drawn from other programming paradigms, in particular concepts from constraint management and data flow. This paper describes the important trade‐offs that have affected the development of PREMO and explains how these are addressed through the use of specific programming paradigms.
Fast Polyhedral Cell Sorting for Interactive Rendering of Unstructured Grids
Authors: Comba João , Klosowsk James T. , Max Nelson , Mitchell Joseph S. B. , Silva Cláudio T. , Williams Peter L.
Published: March 2003

Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell’s color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is “well‐behaved” (acyclic and convex), then the MPVO method of Williams provides a very fast sorting algorithm; however, this method only computes an approximate ordering in general datasets, resulting in visual artifacts when rendered. A recent method of Silva et al. removed the assumption that the mesh is convex, by means of a sweep algorithm used in conjunction with the MPVO method; their algorithm is substantially faster than previous exact methods for general meshes.

In this paper we propose a new technique, which we call BSP‐XMPVO, which is based on a fast and simple way of using binary space partitions on the boundary elements of the mesh to augment the ordering produced by MPVO. Our results are shown to be orders of magnitude better than previous exact methods of sorting cells.
Modelling and Rendering Graphics Scenes Composed of Multiple Volumetric Datasets
Authors: Leu Adrian , Chen Min
Published: March 2003

This paper presents a method for modelling graphics scenes consisting of multiple volumetric objects. A two‐level hierarchical representation is employed, which enables the reduction of the overall storage consumption as well as rendering time. With this approach, different objects can be derived from the same volumetric dataset, and 2D images can be trivially integrated into a scene. The paper also describes an efficient algorithm for rendering such scenes on ordinary workstations, and addresses issues concerning memory requirements and disk swapping.
Haptic Cues for Image Disambiguation
Authors: Faconti G. , Massink M. , Bordegoni M. , De Angelis F. , Booth S.
Published: March 2003

Haptic interfaces represent a revolution in human computer interface technology since they make it possible for users to touch and manipulate virtual objects. In this work we describe a cross‐model interaction experiment to study the effect of adding haptic cues to visual cues when vision is not enough to disambiguate the images. We relate the results to those obtained in experimental psychology as well as to more recent studies on the subject.
Color Distribution ‐ A New Approach to Texture Compression
Authors: Ivanov Denis V. , Kuzmin Yevgeniy P.
Published: March 2003

Texture compression is recently one of the most important topics of 3D scene rendering techniques, because it allows rendering more complicated high‐resolution scenes. However, because of some special requirements for these type of techniques, the commonly used block decomposition approach may introduce visual degradation of image details due to lack of colors. We present here a new approach to texture compression, which allows sharing of one color by several blocks providing a larger number of unique colors in each particular block and the best compression ratio. We also present an iterative algorithm for obtaining distributed colors on a texture, and discuss some advantages of our approach. The paper concludes with comparison of our technique with S3TC and other block decomposition methods.
Dynamic Polygon Visibility Ordering for Head‐Slaved Viewing in Virtual Environments
Authors: Sadagić Amela , Slater Mel
Published: March 2003

This paper presents an approach to visibility called the Viewpoint Movement Space (VpMS) algorithm which supports the concept of dynamic polygon visibility orderings for head‐slaved viewing in virtual environments (VE). The central idea of the approach is that the visibility, in terms of back‐to‐front polygon visibility ordering, does not change dramatically as the viewpoint moves. Moreover, it is possible to construct a partition of the space into cells, where for each cell the ordering is invariant. As the viewpoint moves across a cell boundary typically only a small and predictable change is made to the visibility ordering. The cost to perform this operation represents a notable reduction when compared with the cost of resolving the visibility information from the BSP tree where the classification of the viewpoint with every node plane has to be performed. The paper demonstrates how the subdivision into such cells can represent the basic source for an acceleration of the rendering process. We also discuss how the same supportive data structure can be exploited to solve other tasks in the graphics pipeline.
Real‐Time Simulation of a Stretcher Evacuation in a Large‐Scale Virtual Environment
Authors: Hubbold Roger , Keates Martin
Published: March 2003

This paper presents a case study of navigation and manipulation in a large, geometrically complex, virtual environment representing an off‐shore gas platform. Our approach is based on a combined force‐field navigation and collision detection algorithm. After describing the basic algorithm, we extend and apply it to a real‐time simulation of two avatars carrying a third avatar on a stretcher. The extensions include a probing technique, using a virtual foot and simulated gravity, to permit ascending and descending stairs and ladders. A set of constraints between the stretcher and avatars enforces realistic lifting positions. The simulation is controlled interactively with a hand‐held 3D mouse. The force fields assist the user in manoeuvring through tight spaces, while collision detection guarantees that neither the stretcher nor the avatars can pass through obstructions, such as pipe‐work or hand‐rails. Results are presented for a case study of a complete simulation running on a PC with a moderately fast 3D graphics card. These demonstrate that the method delivers a useful frame rate for the off‐shore gas platform.
Antialiasing of Environment Maps
Authors: Schilling Andreas
Published: March 2003

Environment maps, like texture maps or any other maps consisting of discretely stored data have to be properly filtered, if they are being resampled in the process of rendering an image. For environment maps, this is especially important, as the sampling rate is subject to extreme changes due to the curvature of the reflecting surfaces. However, for the same reason, the antialiasing is especially difficult to perform, as the sampling rate has to be determined for each pixel. We introduce a method to perform this calculation and determine the parameters for anisotropic filtering of the environment map. Instead of the BRDF, we employ roughness pyramids to account for the properties of the reflecting surface. The principles that are used to perform this antialiasing can be applied for antialiasing reflected textures in general e.g. in ray tracing.
A Recursive Subdivision Algorithm for Piecewise Circular Spline
Authors: Nasri Ahmad H. , Van Overveld C. W. A. M. , Wyvill Brian
Published: March 2003

We present an algorithm for generating a piecewise G1 circular spline curve from an arbitrary given control polygon. For every corner, a circular biarc is generated with each piece being parameterized by its arc length. This is the first subdivision scheme that produces a piecewise biarc curve that can interpolate an arbitrary set of points. It is easily adopted in a recursive subdivision surface scheme to generate surfaces with circular boundaries with pieces parameterized by arc length, a property not previously available. As an application, a modified version of Doo–Sabin subdivision algorithm is outlined making it possible to blend a subdivision surface with other surfaces having circular boundaries such as cylinders.
Constrained Fairing for Meshes
Authors: Liu Xinguo , Bao Hujun , Heng PhengAnn , Wong TienTsin , Peng Qunsheng
Published: March 2003

In this paper, we present a novel fairing algorithm for the removal of noise from uniform triangular meshes without shrinkage and serious distortion. The key feature of this algorithm is to keep all triangle centers invariant at each smoothing step by including some constraints in the energy minimization functional. The constrained functional is then minimized efficiently using an iterative method. Further, we apply this smoothing technique to a multiresolution representation to remove arbitrary levels of detail. A volume‐preserving decimation algorithm is presented to generate the multiresolution representation. The experimental results demonstrate the combined algorithm's stability and efficiency.
Haptic Device Control – Will it Fit Standardized Input Models?
Authors: Arnold D. B. , Day A. M. , Jennings V. , Courtenay A. , Duce D. A.
Published: March 2003

Over recent years a wide variety of interaction devices involving haptic feedback have been brought to the market, but they vary widely in terms of input measures recorded. These range from one dimensional input on a haptic feedback steering wheel to a six degree of freedom position and orientation device and further, to assemblies of such devices. On the surface most of the variations can be accommodated logically with standardized input models combining existing logical input devices and haptic feedback processes as acknowledgement/echos. However it is very uncertain whether such a model can adequately model the system requirements for effective haptic feedback.

In this paper we review the input models that have developed over the past 20 years and ask “Is it the end of the road for the conceptual model of input incorporated into the early graphics standards and elaborated over the years?” In addition, to highlight the problems of implementation with haptic interaction, we describe a typical application, the simulation of a collision with a virtual wall.
CP3: Robust, Output‐sensitive Display of Convex Polyhedra in Scanline Mode
Authors: Barkan Ella , Gordon Dan
Published: March 2003

A new technique is developed for displaying disjoint convex polyhedra. The method has the following properties: It is output‐sensitive, displays the objects in scanline mode, and it is naturally robust. There is no complex data structure uniting the different polyhedra, so dynamic insertions and deletions are simple. Its robustnes is based on a novel method of comparing depths by representative “axes” of objects instead of surfaces. The method is based on two extensions of the “critical‐points” method for polygon scan conversion: One extension allows the efficient display of planar graphs in scanline mode, and another extension is into the third dimension. Test runs indicate that it compares extremely favorably with other methods that operate in scanline mode, as well as with standard software and hardware techniques of medium‐level workstations.
Simulation of Facial Muscle Actions Based on Rational Free Form Deformations
Authors: Kalra Prem , Mangili Angelo , Thalmann Nadia Magnenat , Thalmann Daniel
Published: March 2003

This paper describes interactive facilities for simulating abstract muscle actions using Rational Free Form Deformations (RFFD). The particular muscle action is simulated as the displacement of the control points of the control‐unit for an RFFD defined on a region of interest. One or several simulated muscle actions constitute a Minimum Perceptible Action (MPA), which is defined as the atomic action unit, similar to Action Unit (AU) of the Facial Action Coding System (FACS), to build an expression.
Implementing RenderMan ‐ Practice, Problems and Enhancements
Authors: Slusallek Philipp , Pflaum Thomas , Seidel Hans‐Peter
Published: March 2003

The RenderMan interface has been proposed as a general interface to rendering systems, yet only a few implementations of the interface exist. In this paper we describe the implementation of the RenderMan interface on a general rendering architecture that supports various rendering algorithms. Specifically we discuss the implementation of the RenderMan Shading Language and its integration into our rendering architecture. Special attention is focused on the problems that we have encountered and how they can be solved. Additionally, we suggest extensions and enhancements to the current interface definition, which would make RenderMan easier to implement and more flexible to use.
Animation using NURBS
Authors: Preston M. , Hewitt W. T.
Published: March 2003

All animation, whether generated by pen or processor, is concerned with the changing behaviour of synthetic actors through time. Computer animation has allowed an animator to regard different actors as functionally equivalent entities for the purpose of generating their behaviours. This has opened the door to visually impressive effects, such as actors changing their appearance, thereby becoming other actors.

For NURBS to become a tool which is useful to the writer of animation packages, it is necessary to provide this ability to in‐between objects of different appearances through time.

This paper aims to present a technique for creating higher dimensional NURBS to model object deformation, as well as to illustrate its advantages.
Topologically exact evaluation of polyhedra defined in CSG with loose primitives
Authors: Banerjee Raja (P.K.) , Rossignac Jarek R.
Published: March 2003

Floating point round‐off causes erroneous and inconsistent decisions in geometric modelling algorithms. These errors lead to the generation of topologically invalid boundary models for CSG objects and significantly reduce the reliability of CAD applications. Previously known methods that guarantee topological consistency by relying on arbitrary precision rational arithmetic or on symbol‐manipulation techniques are too expensive for practical purposes. This paper presents a new solution which takes as input a “fixed precision” regularized Boolean combination of linear half‐spaces and produces a polyhedral boundary model that has the exact topology of the corresponding solid. Each half‐space is represented by four homogeneous coefficients infixed precision format (La bits for the three direction cosines and Ld bits for the constant term, i.e. the distance from the origin). Exact answers to all topological and ordering questions are computed using a fixed length, 3 La+ Ld+ 2 bits, integer format. This new guaranteed tight limit on the number of bits necessary for performing intermediate calculations is achieved by expressing all of the topological decisions based on geometric computations in terms of the signs of 4 by 4 determinants of the input coefficients. The coordinates of intersection vertices are not required for making the correct topological decisions and hence vertices and lines are represented implicitly in terms of planes.
Introduction: The Meaning and Employment of ‘Civil Society’ in Latin America
Authors: Avritzer Leonardo
Published: March 2003

This article discusses the recent adoption of the concept of civil society by Latin American social movements and political theorists. Our argument is that civil society has been employed in two contexts in Latin America: 1) in the re‐interpretation of the ambiguous reception of liberalism in the region; 2) in the analysis of the constitution of a realm of societal autonomy throughout the struggle against authoritarianism. It is our contention in this article that social movements and civil associations are playing a central role in both processes.
Totalitarianism After the Fall
Authors: Flynn Bernard
Published: March 2003

Book reviewed in this article:

Claude Lefort, La Complication: Retour Sur Communisme
Modern Company Law for a Competitive Economy: the strategic framework
Authors: Monks Robert
Published: March 2003

The author has made significant theoretical contributions to the literature of corporate governance, with works such as Corporate Governance, The Emperor’s Nightingale and Power and Accountability, and major practical interventions through his representational investing through his vehicle the Lens Fund and, more recently, Hermes Fund. He is a distinguished member of this journal’s Editorial Advisory Board. In this paper he responds to the recent UK Department of Trade and Industry consultation document on the future of company law in Britain. We believe that this contribution highlights some important aspects of the corporate governance debate, as well as arguing to some interesting possibilities for the UK. Although the paper stands on its own, references to ‘The Strategic Framework’ have been left in for scholars wishing to explore the arguments further.
Corporate Governance in Emerging Capital Markets: whither Africa?
Authors: Rwegasira Kami
Published: March 2003

Having debated the pros and cons of alternative governance models in the developed market economies, a case is made for Africa’s choice to be in the direction of the institutionally‐based model. It is emphasized however that the African economies which are restructuring need to adapt the model to the peculiarities of specific economies and that the inputs from more than a single model will be necessary to provide for globally competitive capital markets in these economies.
Corporate Governance in the Russian Federation: the relevance of the OECD Principles on shareholder rights and equitable treatment
Authors: Jesover Fianna
Published: March 2003

Despite progress in developing extensive legislation and regulations, there is still a long way to go before the standards of corporate governance in Russia will instil widespread confidence in investors. The emphasis is now on their implementation and enforcement by the state and private sector institutions. Transparent, equitable rules and predictable enforcement mechanisms are necessary to make the Russian economy attractive to both domestic and foreign investors, and enhance public confidence in the overall reform process. This paper uses the first two chapters of the OECD Principles of Corporate Governance on shareholder rights and their equitable treatment and looks through their prism at the Russian corporate governance condition.
Building of a Corporate Governance System in Poland: initial experiences
Authors: Koladkiewicz Izabela
Published: March 2003

The process of building a corporate governance system in Poland is an ongoing one. It may be assumed, however, that the past ten years have seen the foundation created for the system. The institution of the supervisory board occupies an essential position within the infrastructure. For its part, the developing capital market, with such important institutions as the Securities and Exchange Commission as well as the Stock Market, fills a significant – though not yet broad – supporting function. It must be remembered, however, that the Polish system of corporate governance is still very young and is subject to continuous transformations. To a great extent, the direction of these transformations is marked by the quest for ever more effective solutions in the realm of supervision whilst the pool of experience already accumulated makes possible the implementation of the selected orientation.
The Effect of Board Changes on Writedowns of Non–Current Assets: evidence from New Zealand
Authors: Ahmed Kamran , Roush Melvin
Published: March 2003

This study reports the results of an empirical study that examined the impact of changes in the board of directors on writedowns of non–current assets. Using 337 annual reports of the firms listed on the New Zealand Stock Exchange for 7 years from 1993 to 1999, the results show that changes in the board of directors is a statistically significant determinant of both writedown decision and the dollar amount of writedowns. The results also show that the regression coefficient and the significance level of board restructure are materially higher when changes in chief executive officer are incorporated in the model estimation. Corporate firm size, as measured by total assets at balance date, is found to be another significant determinant. Other corporate attributes such as leverage, operating performance and term borrowings in the subsequent years are not significant factors. However, a firm's growth opportunities provide some support in explaining the dollar amount of writedowns. The results are robust to alternative proxies and the time effect is not evident over the 7–year period.
Knowledge Management Focus in US and Canadian Firms
Authors: Covin Teresa Joyce , Stivers Bonnie P.
Published: March 2003

Experts predict that as we approach the year 2000, employee brainpower and other knowledge resources are rapidly becoming the most important factors driving business profitability. The challenge for organizations over the next decade will be to understand the role of knowledge resources in creating value for firms. This article provides three perspectives to understand the notion of knowledge management. The first section provides an overview of trends and issues that highlight the emergence of the knowledge era. The second section of the article recaps the results of a survey of Fortune 500 and Post 300 firms that the authors conducted to learn about knowledge management practices. The last section of the article provides guidelines for getting started in knowledge management.
Book of the Quarter
Authors: Rickards Tudor
Published: March 2003

Reid, Robert H. Architects of the Web: 1000 days that built the future of business
The Voice of the Product: Templates of New Product Emergence
Authors: Goldenberg Jacob , Mazursky David
Published: March 2003

The paper presents a new framework of analyzing the product itself to infer about future market demands. This framework consists of past regularities that were identified to underlie the emergence of successful new products. By identifying templates of innovation an innovator may be able to predict the future product even before the market signals the needs or when the market information is not accessible. If successful in predicting new products by inspecting the product itself, innovation can be supported by the proposed knowledge system (i.e., the self catalytic dynamics of product evolution) which is invariant to market information. When market information is not accessible (typically in case of latent needs, genuinely new products) the product‐based information is sufficiently effective to help in predicting future demands. The conclusion is that reflective practitioners should actively listen to the product and its trends as another source for ideation, because there is more relevant information embedded in the internal dynamics of product evolution than previously recognized in marketing practice.
New Technology Introduction and Implementation: The Case of Paging Technology in the Ratlam Division of Indian Railways
Authors: Richardson Pikay , Nigam Ajit
Published: March 2003

Concomitant to the liberalisation policy and market reforms in India has been the issue of declining budgetary support for public sector organisations. Hitherto, Indian Railways, the biggest publicly‐owned enterprise, has largely been supported by the exchequer. Since the early 1990s, however, the Railways has had to operate increasingly as a commercial rather than a social organisation. One of the ways of improving efficiency is to introduce efficiency‐enhancing technologies. This paper is a case study of the introduction of paging technology to the Ratlam Division of Indian Railways. It describes the process of planning and implementation, the HRM implications of the adoption and how the process was successfully managed. It aims at shedding further light on the nature and the processes whereby technologies eventually gain company recognition and acceptance.
Goals, Creativity and Achievement: Commitment in Contemporary Organizations
Authors: Swailes Stephen
Published: March 2003

This paper questions the nature of organizational commitment in the light of contemporary competitive environments, the emergence of human resource management practices and reshaped employee‐organization linkages. Qualitative research among organizational professionals suggests that the classical view of organizational commitment as a positive attitudinal state has been overtaken by a more complex view that embraces task‐related goal congruence, energies directed at achieving outcomes and creative and innovative behaviours in the workplace. Stepwise regression analysis was used to examine the predictors of goal congruence, achievement and innovative behaviours in a sample of over 600 chemists and accountants.
Open Doors to Leading Projects: Your New Chance to Understand and Perform Project Leadership
Authors: Bech Nils
Published: March 2003

Project management and project leadership are activities that inter‐relate. However, a knowledge of the differences between the overlapping sets of activities can enhance the procedures and outcomes of projects. The differences are illustrated through a visual metaphor of seven doors that open to reveal different leadership and management spaces as a project progresses.
Regimes of Knowledge, Stories of Power: A Treatise on Knowledge Management
Authors: Carter Chris , Scarbrough Harry
Published: March 2003

Discussions on Knowledge Management have to date been largely uncritical, ignoring the broader political implications of attempting to manage ‘knowledge’. More recently there have been numerous calls to engage with the issue of knowledge in organizations in a more critical manner. The objective of this paper is to contribute to a critical discussion through unpacking the issue of knowledge in organizations through reference to the empirical data gained from a study of CoastElectric, a regional electricity company. In the paper we argue that organizations can be thought of regimes of knowledge, whereby the capabilities of an organization are interwoven with the relations of power.