bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ray Tracing Animated Scenes using Motion Decomposition
Authors: Günther Johannes , Friedrich Heiko , Wald Ingo , Seidel Hans‐Peter , Slusallek Philipp 
Published: December 2006

Abstract Though ray tracing has recently become interactive, its high precomputation time for building spatial indices usually limits its applications to walkthroughs of static scenes. This is a major limitation, as most applications demand support for dynamically animated models. In this paper, we present a new approach to ray trace a special but important class of dynamic scenes, namely models whose connectivity does not change over time and for which all possible poses are known in advance. We support these kinds of models by introducing two new concepts: motion decomposition, and fuzzy kd‐trees. We analyze the animation and break the model down into submeshes with similar motion. For each of these submeshes and for every time step, we calculate a best affine transformation through a least square approach. Any residual motion is then captured in a single "fuzzy kd‐tree" for the entire animation. Together, these techniques allow for ray tracing animations without rebuilding the spatial index structures for the submeshes, resulting in interactive frame rates of 5 to 15 fps even on a single CPU. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Ray tracing I.3.6 [Methodology and Techniques]: Graphics data structures and data types
Direct (Re)Meshing for Efficient Surface Processing
Authors: Schreiner John , Scheidegger Carlos E. , Fleishman Shachar , Silva Cláudio T. 
Published: December 2006

Abstract We propose a novel surface remeshing algorithm. While many remeshing algorithms are based on global parametrization or local mesh optimization, our algorithm is closely related to surface reconstruction techniques and it requires no explicit parameterization. Our approach is based on the advancing‐front paradigm, and it can be used to both incrementally remesh the complete surface, or simply to remesh a portion of it with a high‐quality mesh. It is accurate, fast, robust, and suitable for use with interactive mesh processing applications that require local remeshing. We show a number of applications, including matching the resolution of meshes when doing Boolean operations such as unions and intersections. We also show how to adapt the algorithm to blend and merge mixed‐mode objects — for example, to compute the union of a point‐set surface and a triangle mesh.
Computing discrete shape operators on general meshes
Authors: Grinspun Eitan , Gingold Yotam , Reisman Jason , Zorin Denis 
Published: December 2006

Abstract Discrete curvature and shape operators, which capture complete information about directional curvatures at a point, are essential in a variety of applications: simulation of deformable two‐dimensional objects, variational modeling and geometric data processing. In many of these applications, objects are represented by meshes. Currently, a spectrum of approaches for formulating curvature operators for meshes exists, ranging from highly accurate but computationally expensive methods used in engineering applications to efficient but less accurate techniques popular in simulation for computer graphics. We propose a simple and efficient formulation for the shape operator for variational problems on general meshes, using degrees of freedom associated with normals. On the one hand, it is similar in its simplicity to some of the discrete curvature operators commonly used in graphics; on the other hand, it passes a number of important convergence tests and produces consistent results for different types of meshes and mesh refinement.
Opacity Peeling for Direct Volume Rendering
Authors: Rezk‐Salama Christof , Kolb Andreas 
Published: December 2006

Abstract The most important technique to visualize 3D scalar data, as they arise e.g. in medicine from tomographic measurement, is direct volume rendering. A transfer function maps the scalar values to optical properties which are used to solve the integral of light transport in participating media. Many medical data sets, especially MRI data, however, are difficult to visualize due to different tissue types being represented by the same scalar value. The main problem is that interesting structures will be occluded by less important structures because they share the same range of data values. Occlusion, however, is a view‐dependent problem and cannot be solved easily by transfer function design. This paper proposes a new method to display different entities inside the volume data in a single rendering pass. The proposed opacity peeling technique reveals structures in the data set that cannot be visualized directly by one‐or multi‐dimensional transfer functions without explicit segmentation. We also demonstrate real‐time implementations using texture mapping and multiple render targets. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three‐Dimensional Graphics and Realism
Virtual Garments: A Fully Geometric Approach for Clothing Design
Authors: Decaudin Philippe , Julius Dan , Wither Jamie , Boissieux Laurence , Sheffer Alla , Cani Marie‐Paule 
Published: December 2006

AbstractModeling dressed characters is known as a very tedious process. It usually requires specifying 2D fabric patterns, positioning and assembling the min 3D, and then performing a physically‐based simulation. The latter accounts for gravity and collisions to compute the rest shape of the garment, with the adequate folds and wrinkles.This paper presents a more intuitive way to design virtual clothing. We start with a 2D sketching system in which the user draws the contours and seam‐lines of the garment directly on a virtual mannequin. Our system then converts the sketch into an initial 3D surface using an existing method based on a precomputed distance field around the mannequin. The system then splits the created surface into different panels delimited by the seam‐lines. The generated panels are typically not developable. However, the panels of a realistic garment must be developable, since each panel must unfold into a 2D sewing pattern. Therefore our system automatically approximates each panel with a developable surface, while keeping them assembled along the seams. This process allows us to output the corresponding sewing patterns.The last step of our method computes a natural rest shape for the 3D garment, including the folds due to the collisions with the body and gravity. The folds are generated using procedural modeling of the buckling phenomena observed in real fabric. The result of our algorithm consists of a realistic looking 3D mannequin dressed in the designed garment and the 2D patterns which can be used for distortion free texture mapping. The patterns we create also allow us to sew real replicas of the virtual garments.Keywords:Geometric modeling of garments, developable surfaces, procedural models, buckling.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computing Methodologies/Computer Graphics]: Surface representations, I.3.7 [Computing Methodologies/Computer Graphics]: Three‐dimensional graphics and realism
Stroke Pattern Analysis and Synthesis
Authors: Barla Pascal , Breslav Simon , Thollot Joëlle , Sillion François , Markosian Lee 
Published: December 2006

Abstract We present a synthesis technique that can automatically generate stroke patterns based on a user‐specified reference pattern. Our method is an extension of texture synthesis techniques to vector‐based patterns. Such an extension requires (a) an analysis of the pattern properties to extract meaningful pattern elements (defined as clusters of strokes) and (b) a synthesis algorithm based on similarities in the detected stroke clusters. Our method is based on results from human vision research concerning perceptual organization. The resulting synthesized patterns effectively reproduce the properties of the input patterns, and can be used to fill both 1D paths and 2D regions. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Color, shading, shadowing, and texture I.3.4 [Computer Graphics]: Paint systems
Pose Controlled Physically Based Motion
Authors: Fattal Raanan , Lischinski Dani 
Published: December 2006

Abstract In this paper we describe a new method for generating and controlling physically‐based motion of complex articulated characters. Our goal is to create motion from scratch, where the animator provides a small amount of input and gets in return a highly detailed and physically plausible motion. Our method relieves the animator from the burden of enforcing physical plausibility, but at the same time provides full control over the internal DOFs of the articulated character via a familiar interface. Control over the global DOFs is also provided by supporting kinematic constraints. Unconstrained portions of the motion are generated in real time, since the character is driven by joint torques generated by simple feedback controllers. Although kinematic constraints are satisfied using an iterative search (shooting), this process is typically inexpensive, since it only adjusts a few DOFs at a few time instances. The low expense of the optimization, combined with the ability to generate unconstrained motions in real time yields an efficient and practical tool, which is particularly attractive for high inertia motions with a relatively small number of kinematic constraints.
Physically Based Deformable Models in Computer Graphics
Authors: Nealen Andrew , Müller Matthias , Keiser Richard , Boxerman Eddy , Carlson Mark 
Published: December 2006

AbstractPhysically based deformable models have been widely embraced by the Computer Graphics community. Many problems outlined in a previous survey by Gibson and Mirtich have been addressed, thereby making these models interesting and useful for both offline and real‐time applications, such as motion pictures and video games. In this paper, we present the most significant contributions of the past decade, which produce such impressive and perceivably realistic animations and simulations: finite element/difference/volume methods, mass‐spring systems, mesh‐free methods, coupled particle systems and reduced deformable models‐based on modal analysis. For completeness, we also make a connection to the simulation of other continua, such as fluids, gases and melting objects. Since time integration is inherent to all simulated phenomena, the general notion of time discretization is treated separately, while specifics are left to the respective models. Finally, we discuss areas of application, such as elastoplastic deformation and fracture, cloth and hair animation, virtual surgery simulation, interactive entertainment and fluid/smoke animation, and also suggest areas for future research.
“Rethinking” the Preface of the Tractatus
Authors: Howes Bruce 
Published: December 2006

AbstractThis paper is principally a re‐evaluation of the meaning of Denken in the puzzling third paragraph of the Preface to Wittgenstein's Tractatus. It shows that there is a uniform misreading of this paragraph throughout the literature and suggests a corrected reading and some of its implications. The paper asserts that the influential “New Wittgenstein” reading of the Preface as containing Wittgenstein's all important “framing” thoughts on the Tractatus, is correct. However it also argues that the anti‐metaphysical reading the New view draws by way of its frame thesis is incorrect since it is still premised on the incorrect reading of the Preface's third paragraph. With the correct reading of the third paragraph, the paper shows the anti‐metaphysical reading of the Tractatus lacks substantive support.
Reliabilism, Proper Function, and Serendipitous Malfunction
Authors: Bardon Adrian 
Published: December 2006

AbstractAlvin Plantinga's externalist analysis of epistemic warrant centres on the proper function of the relevant belief‐forming mechanism, where proper function is fixed relative to the design plan of the organism in question. He has set this analysis against reliabilism, the other leading externalist contender for the analysis of warrant. Though Plantinga's discussion advances the field of epistemology in a number of important ways, his treatment of warrant is limited by his assumption of creationism in his understanding of design and function. Further, analyses of epistemic warrant focusing on function over reliability either fail at handling problem cases reliabilism can handle, or fail to improve on problem cases for reliabilism. Thus no proper functionalist analysis like Plantinga's can supersede a well‐constructed reliabilist analysis.
Optimal Financial Structure, Cost of Capital, and the Lease‐or‐Buy Decision
Authors: KELLER THOMAS F. , PETERSEN RUSSELL J. 
Published: December 2006

This note comments on the doubtful application of an economic concept of personal income to the non‐personal business enterprise situation.This paper presents a series of models which we believe properly reflect the relevant relationships in the lease or buy evaluation. The models present the proper cash flow variables for such an analysis and they present the impact on asset net present value of cost of capital and market risk assessment. Finally, the models reflect the simultaneous effect on asset and financial structure of the acceptance of a particular investment opportunity.
Dividend Policy and Market Valuation in British Industry
Authors: RYAN TERENCE M. 
Published: December 2006

The objectives of the article are: firstly, to identify the principal factors which determine interfirm variation in dividend policy within the UK; and secondly, to examine the effect of dividend policy on company stock‐market valuation. This cross‐section empirical study is based on a random sample of 60 publiclyquoted British companies, and refers to the year 1970.The Lintner (1956) model is rejected, in that capital requirements and earnings risk are seen to play an important part in determining dividend policy. The ‘dividend neutrality’ hypothesis is strongly rejected once risk and profitability‐of‐retained‐earnings are taken into account.
The Development of the Capital Structure of German Companies*
Authors: ALBACH PROFESSOR HORST 
Published: December 2006

The capital structure of Federal German companies has developed in a noteworthy fashion in the last twenty years, but incentive to undertake investments is declining in the face of a falling return on equity capital, and the possibilities for investment financing are becoming narrower. If the trend of the last few years continues, serious difficulties may arise in the financing of company growth. This paper attempts to measure the development of the capital structure, financial structure, and financial strength of German companies by means of various indices.Durant les vingt dernières années, la structure financière des sociétés de l'Allemagne fédérale s'est développée de façon remarquable, mais l'encouragement aux investissements s'affaiblit devant la baisse de rentabilité des capitaux propres, et les possibilités concernant le financement des investissements deviennent plus limitées. Si la tendance des quelques dernières années persiste, cela risque d'entraîner de sérieuses difficultés dans le financement visant à l'essor des entreprises. Ce papier tente àévaluer, au moyen de divers indices, le développement qu'a subi la structure financière, et la résistance financière des sociétés allemandes.Die Kapitalstruktur der deutschen Aktiengesellschaften hat sich in den letzten zwanzig Jahren in bemerkenswerter Weise entwickelt. Die Bilanzanylse zeigt, dass nicht nur der Anreiz Investitionen zu tätigen angesichts sinkender Verzinsung des Eigenkapitals abnimmt, sondern dass auch die Moglichkeiten, Investitionen zu finanzieren, immer mehr eingeengt werden. Wenn sich der Trend der letzten Jahre fortsetzt, muss mit ernsten Finanzierungsschwierigkeiten für das Wachstum der Unternehmen in der Bundesrepublik Deutschland gerechnet werden. Dieser Beitrag will die Entwicklung der Kapitalstruktur deutscher Unternehmen an Hand einiger Kennzahlen sichtbar machen. Die Zahlen über die Kapitalstruktur werden um Kennzahlen der Finanzstruktur und der Finanzkraft ergänzt.
Portfolio Performance with Lending or Borrowing
Authors: MATULICH SERGE 
Published: December 2006

The availability of a single riskless lending and borrowing interest rate is one of the underlying assumptions of the two‐parameter efficient markets model. When the model is used to evaluate ex‐post portfolio performance this assumption becomes too restrictive. For investors facing a borrowing rate which is higher than the lending rate, performance evaluation must take into account investment goals. It is also necessary to recognize that investors willing to assume high risk in order to obtain high returns have available a number of alternative portfolios which are efficient.La disponibilité d'un simple taux d'intérêt sur prêt ou emprunt, tout risque exclu, est une des hypothèses fondamentales du modèle des marchés actifs à deux paramètres. Lorsque le modèle sert àévaluer le rendement expost de portefeuille, cette hypothèse s'avère trop limitée. Dans le cas où les investisseurs se trouvent face à un taux d'emprunt supérieur au taux de prêt, l'évaluation du rendement doit s'effectuer en considbration des objectifs d'investissements. II faut de même préciser que les investisseurs, prêts à edosser de grands risques dans le but d'obtenir des bényéfices élevés, possèdent un nombre disponible de portefeuilles alternatifs qui sont productifs.Das Vorhandensein eines einzigen risikofreien Anlage‐ und Aufnahmezinssatzes stellt eine der grundsätzlichen Voraussetzungen des zweiparameterischen Effizientmarkt‐Modells dar. Bei der Verwendung des Modells für die Ermittlung der ex post Portefeuilleleistung wird diese Voraussetzung zu einschränkend. Für Anleger, die einen Aufnahmezinssatz, der den Anlagezinssatz überschreitet, bezahlen müssen, muss die Leistungsermittlung Investitionsziele berücksichtigen. Ebenfalls muss berücksichtigt werden, dass Anleger, die hohe Risiken eingehen um hohe Erträge zu erreichen, über eine Anzahl von alternativen effizienten Portefeuillen verfügen.
The Contribution of Fisher to Enterprise Income Theory: A Comment
Authors: LEE T. A. 
Published: December 2006

Income is indeed a will‐o'‐the‐wisp. One of its modem founding fathers was Irving Fisher, who emphasized the psychic experience of consumption. This paper discusses some aspects of Fisher's contribution to the continuipg debate on the elusive concept of income.Le revenu est un vrai feu follet. Un de ses fondateurs actuels fut Irving Fisher qui fit valoir l'aspect psychique de la consommation. Ce papier examine certains aspects de l'intervention de Fisher dans les débats incessants dirigés sur I'insaisissable concept du revenu.Das Ertragskonzept ist allerdings ein Irrlicht. Einer seiner modernen Stamniväter war Irving Fisher, der die pschische Erfahrung yon Verbrauch zum Ausdruck brachte. Diese Abhandlung besprict einige Aspekte des Fisher‐Beitrages zur fortdauernden Debatte uber das schwer erfassbare Ertragskonzept.
The Cost of Equity Capital—A Reply
Authors: GRINYER JOHN R. 
Published: December 2006

Hemsted (JBFA I, 3) claimed that the expected internal rate of return, and not the shareholders' opportunity cost, is the ‘cost of equity’. This paper shows, using his assumed objective of maximization of share price and chosen (Gordon Shapiro) share valuation model, that his claims are unfounded, and that, under specified assumptions, the shareholders' opportunity cost is the required criterion rate.Selon Hemsted c'est le taux de rendement interne, et non pas le coût d'opportunitk des actionnaires, qui est le coût des capitaux propres. S1 appuyant sur ce prétendu objectif de maximation de la valeur d'une action et optant sur le modèle d'évaluation d'une action de Gordon Shapiro, ce papier montre que ce qu áffirme Hemsted est sans fondement, et que, selon des hypotheses determinées le coût d'opportunité des actionnaires est le coût fondamental requis.Hemsted (JBFA I, 3) behauptete, dass der erwartete interne Zinsfuss und nicht die Aktionärsopportunitätskosten die Eigenkapitalkosten darstellt. Dieser Beitrag zeigt, dass mit Anlehnung an seine vorausgesetzte Aktienkursmaximierungszielfunktion und sein ausgewahltes (Gordon Shapiro) Aktienbewertungsmodell, diese Behauptungen unbegründet sind. Unter bestimmten Voraussetzungen stellen die Aktionärsopportunitatskosten die Eigenkapitalkosten dar.
The Valuation of Stock Warrants: A Reply
Authors: BIRD A. P. 
Published: December 2006

The warrant model is shown to be serviceable for practical purposes, and some of Skerratt's criticisms are shown to be wrong. Nevertheless, there is scope for further work on the model, both on some of the points Skerratt has raised and in other areas.On définit le modèle concernant le warrant comme étant destinéà des fonctions pratiques et on met en évidence certaines des critiques apportées par Skerratt qui semblent ma1 fondées. II faut toutefois ajouter qu'une etude plus approfondie du modele est entreprise, celle‐ci s'appuyant à la fois sur certains points soulevés par Skerratt et sur d'autres critères.
A NOTE ON THE SUPERIORITY OF LEVERED SHARES UNDER THE POSITIVE NPV RULE
Authors: KEANE SIMON M. 
Published: December 2006

The purpose of this note is to demonstrate that under the market conditions upon which the validity of the positive NPV rule in capital budgeting depends, levered shares will on average out‐perform unlevered shares to a degree which more than compensates for the additional risk.Dans ce papier, on démontre que ‐ dans les conditions du marché dont dépend la validité du principe de la valeur actuelle nette relative aubudget en capital ‐ les titres sujets au leverage donneront en moyenne de meilleurs rendements que ceux qui ne le sont pas, couvrant ainsi largement le risque supplémentaire.Der Zweck dieser Amerkung ist es zu zeigen, dass unter den Marktbedingungen, mvon die Gültigkeit der Kapitalwertmethode im Rahmen der Investitionsplanung abhägt, die Aktienrendite eines verschuldeten Unternehmens die Aktienrendite eines nicht‐verschuldeten Unternehmens hinsichtlich des Verschuldungsrisikos überkompensiert.
A COMMENT ON TWO SIMPLE DECISION RULES IN CAPITAL RATIONING
Authors: NORTRØM CARL J. 
Published: December 2006

The elegant solution of the capital rationing problem through linear or integer programing is of limited use in practical situations due to strong requirements of available information. The purpose of the article is to give conditions under which two simpler decision rules, present value per dollar outlay and internal rate of return, will lead to essentially the same solution as the linear programming approach. The conditions are given in terms of the shadow discount rates of the linear programing solution.L'elégénte solution apportée au problème de rationement du capital au moyen de la programmation linèire, a une application limitée dans des situations réelles étant donné les stricts besoins d'informations dont il faudrait disposer. Dans cet article, on donne les conditions ous lesquelles deux principes simples de décision (la valeur actuelle et “Internal rate of return”) permettraient d'aboutir au même résultat que celui de la méthode linéaire de progammation. Les conditions sont données au moyen de taux d'escompte correspondants appropriés a la solution fournie par la progarnation linéaire.Die elegante Lösung des Investitionsplans bei beschränkten Finanzierungsmitteln durch lineare oder ganzzahlige Programierung ist von begrenztem Nutzen in der Praxis, da die nötigen Informationen nicht zure Verfüngung stehen. Der Zweck des Beitrages ist eine Erleuterung der Bedingungen, worin zwei einfachere Entscheidungsregeln, Kapitalwert pro Dollar des Anschaffungspreises und interner Zinfuss, grundsätzlich zur selben Lösung als die lineare Programierung führt. Die Bedingungen werden als Schattendiskontierungsätze der Lgsung eines linearen Programs dargestellt.