waashk/acm huggingface dataset:
real-time simulation of dust behavior generated by a fast traveling vehicle  simulation of physically realistic complex dust behavior is very useful in training, education, art, advertising, and entertainment. there are no published models for real-time simulation of dust behavior generated by a traveling vehicle. in this paper, we use particle systems, computational fluid dynamics, and behavioral simulation techniques to simulate dust behavior in real time. first, we analyze the forces and factors that affect dust generation and the behavior after dust particles are generated. then, we construct physically-based empirical models to generate dust particles and control the behavior accordingly. we further simplify the numerical calculations by dividing dust behavior into three stages, and establishing simplified particle system models for each stage. we employ motion blur, particle blending texture mapping, and other computer graphics techniques to achieve the final results. our contributions include constructing physically- based empirical models to generate dust behavior and achieving simulation of the behavior in real time.  jim x. chen xiadong fu j. wegman
image-based visual hulls  in this paper, we describe an efficient image-based approach to computing and shading visual hulls from silhouette image data. our algorithm takes advantage of epipolar geometry and incremental computation to achieve a constant rendering cost per rendered pixel. it does not suffer from the computation complexity, limited resolution, or quantization artifacts of previous volumetric approaches. we demonstrate the use of this algorithm in a real-time virtualized reality application running off a small number of video streams.  wojciech matusik chris buehler ramesh raskar steven j. gortler leonard mcmillan
computer graphic modeling of american sign language  the essential grammatical information of american sign language (asl) is conveyed through changes in the movement and spatial contouring of the hands and arms. an interactive computer graphic system is described for the analysis and modeling of sign language movement. this system consists of four components. the first component reconstructs actual movements in three dimensions and allows the user to interactively segment and transform the data for later analysis. the second component allows a user to interactively create synthetic signs by specifying angle functions in a jointed model. the third component provides a novel technique for manipulating movement quality independently of spatial path. the fourth component allows the building of complex stimuli and real- time stimulus sequencing for psycholinguistic experiments. the emphasis is on interactive techniques and data structures that allow analysis and modeling of the complex hand and arm movements of american sign language.  jeffrey loomis howard poizner ursula bellugi alynn blakemore john hollerbach
controlling and augmenting legal inferencing: ysh, a case study  if legal inferencing systems are to be used for immediate practical application, they are best constructed by embedding them in other technologies which can assist in augmenting and controlling the course of inferencing. adoption of a (quasi) natural language knowledge representation assists easier development of user interpretative facilities, user control of the course of inferencing and explanation facilities. the paper explains how the datalex workstation software, particularly its inference engine, ysh, implements these approaches.  graham greenleaf andrew mowbray
annual report shows high activity every year, each director on the siggraph executive committee compiles an annual report for the annual siggraph organization report. to keep the overall report from becoming a book, the siggraph chair must pick highlights from each area. this issue's _computer graphics_ column contains my full annual report as presented to the siggraph executive committee i hope that it helps to give you a better understanding of the structure of the professional chapters, the events we sponsor at the annual conference and what it is we do over the course of a typical year. please keep in mind that this report is for the 1998-99 year so some information dates back to siggraph 98. as always, if you have any questions or comments, feel free to email me at **lang@siggraph.org.** scott lang
kizamu: a system for sculpting digital characters  this paper presents kizamu, a computer-based sculpting system for creating digital characters for the entertainment industry. kizamu incorporates a blend of new algorithms, significant technical advances, and novel user interaction paradigms into a system that is both powerful and unique.  to meet the demands of high-end digital character design, kizamu addresses three requirements posed to us by a major production studio. first, animators and artists want _digital clay_ \\--- a medium with the characteristics of real clay and the advantages of being digital. second, the system should run on standard hardware at interactive rates. finally, the system must accept and generate standard 3d representations thereby enabling integration into an existing animation production pipeline.  at the heart of the kizamu system are adaptively sampled distance fields (adfs), a volumetric shape representation with the characteristics required for digital clay. in this paper, we describe the system and present the major research advances in adfs that were required to make kizamu a reality.  ronald n. perry sarah f. frisken
the integration of subjective and objective data in the animation of human movement  animation of human movement can be based either on analog inputs derived directly from actual movements or on symbolic inputs chosen to produce the desired movement. the former type of input can be quite accurate and objective but is a description of the required movement whereas the latter is often quite imprecise and subjective but provides an analysis of the required movements. two existing systems for a computer based animation are being used to explore the problems involved in integrating such inputs. specifically, animation driven by analog signals from electro-goniometers is integrated with animation derived from labanotation commands; the results are illustrated with a short movie.  t. w. calvert j. chapman a. patla
tiled polygon traversal using half-plane edge functions  existing techniques for traversing a polygon generate fragments one (or more) rows or columns at a time. (a fragment is all the information needed to paint one pixel of the polygon.) this order is non-optimal for many operations. for example, most frame buffers are tiled into rectangular pages, and there is a cost associated with accessing a different page. pixel processing is more efficient if all fragments of a polygon on one page are generated before any fragments on a different page. similarly, texture caches have reduced miss rates if fragments are generated in tiles (and even tiles of tiles) whose size depends upon the cache organization.  we describe a polygon traversal algorithm that generates fragments in a tiled fashion. that is, it generates all fragments of a polygon within a rectangle (tile) before generating any fragments in another rectangle. for a single level of tiling, our algorithm requires one additional saved context (the values of all interpolator accumulators, such as z depth, red, green, blue, etc.) over a traditional traversal algorithm based upon half-plane edge functions. an additional level of tiling requires another saved context for the special case of rectangle copies, or three more for the general case. we describe how to use this algorithm to generate fragments in an optimal order for several common scenarios.  joel mccormack robert mcnamara
an application of color graphics to the display of surface curvature  in developing a mathematical representation for a surface, designers currently must use line drawing graphics to examine the curvature of a line in a plane, a two-dimensional analysis. by combining a result from differential geometry with the use of color raster graphics, the method described in this paper provides a means for the designer to examine surface curvature, a three- dimensional analysis. in particular, a formulation for the gaussian and average curvatures is given and it is shown how these indicate the presence or absence of protrusions, hollows, etc. in a surface, i.e., how, where, and by how much the surface curves.  showing a fourth variable, curvature in this case, over a three-dimensional surface is difficult, if not impossible with traditional line drawing computer graphics. the method described solves this problem by using color as a fourth dimension. examples are given, including both known shapes (torus) and automotive parts (hood, fender).  john c. dill
a language for bitmap manipulation  in this paper we propose that bitmaps, or raster images, should be given full citizen status in the world of computer science. we introduce a calculus of bitmap operations and mumble, a programming language appropriate for describing bitmap computations. we illustrate the use of mumble by several interesting graphical applications. we also discuss the structure of bop, an efficient implementation of the bitmap calculus that is the underpinning of our system.  leo j. guibas jorge stolfi
constrained texture mapping for polygonal meshes  recently, time and effort have been devoted to automatic texture mapping. it is possible to study the parameterization function and to describe the texture mapping process in terms of a functional optimization problem. several methods of this type have been proposed to minimize deformations. however, these existing methods suffer from several limitations. for instance, it is difficult to put details of the texture in correspondence with features of the model, since most of the existing methods can only constrain iso-parametric curves.  we introduce in this paper a new optimization-based method for parameterizing polygonal meshes with minimum deformations, while enabling the user to interactively define and edit a set of constraints. each user-defined constraint consists of a relation linking a 3d point picked on the surface and a 2d point of the texture. moreover, the non-deformation criterion introduced here can act as an extrapolator, thus making it unnecessary to constrain the border of the surface, in contrast with classic methods. to minimize the criterion, a conjugate gradient algorithm is combined with a compressed representation of sparse matrices, making it possible to achieve a fast convergence.  bruno levy
progressive compression of arbitrary triangular meshes  in this paper we present a mesh compression method based on a multiresolution decomposition whose detail coefficients have a compact representation and thus smaller entropy than the original mesh. given an arbitrary triangular mesh with an irregular connectivity, we use a hierarchical simplification scheme, which generates a multiresolution model. by reversing the process we define a hierarchical progressive refinement process, where a simple prediction plus a correction is used for inserting vertices to form a finer level. we show how the connectivity of an arbitrary triangulation can be encoded efficiently by a coloring technique, and recovered incrementally during the progressive reconstruction of the original mesh.  daniel cohen-or david levin offir remez
developing computational models of discretion to build legal knowledge based systems  few legal knowledge based systems have been constructed which provide numerical advice. none have been built in discretionary domains. our research, directed towards the domains of sentencing and family law property division has lead to the development of three distinct forms of judicial discretion.  to model these different discretionary domains we use diverse artificial intelligence tools including case-based reasoning and knowledge discovery from databases. we carry out a detailed comparison of two discretionary legal knowledge based systems. judge's apprentice is a case- based reasoner which recommends ranges of sentences for convicted israeli rapists and robbers. splitup uses knowledge discovery from databases to learn what percentage of marital property the partners to a divorce in australia will receive. the systems are compared with regard to reasoning, explanation, evaluation and coping with conflicting cases.  yaakov hacohen kerner uri schild john zeleznikow
an action-based ontology of legal relations  this paper aims at linking the ai notion of action to the notion of legal relation. legal rules concern actions to accomplish or to exclude and states to achieve or to avoid. the body of the rule establishes who and under which conditions must respect the obligation. in this paper, we introduce a definition of _obligation_ and use it as an ontological basis to describe the legal relations appearing in the a-hohfeld language.  guido boella lyda favali leonardo lesmo
designing special-purpose input devices for an increasing number of applications, we may be reaching the point of diminishing returns with general purpose computer input devices, such as the keyboard and mouse. at digital image design incorporated (did) we've created special purpose input devices to perform tasks that are commonly addressed with software and general purpose devices alone. these more specific devices have led to significant advantages in accomplishing the tasks, and we've developed an approach to designing these devices that i hope will help others in doing similar work.when someone says "build us a system to speed up computer character animation," the typical solution is purely software. this is not necessarily optimal or even cost effective, and the only way to determine that is to consider developing a hardware device during the initial project exploration. let's go through the process of designing a special purpose device together. real-world details are critical to this process, so we'll do it in the problem domain of animation, where did and others have previously developed special purpose input devices. i'll generalize where appropriate. w. bradford paley
slam iitm tutorial  in 1979, the state-of-the-art in simulation languages was extended with the introduction of slamtm, the first language that provided three different modeling viewpoints in a single integrated framework.(5) slam permits discrete event, continuous, and network modeling perspectives and/or any combination of the three to be implemented in a single model. slam represented a significant breakthrough in simulation methods development, as it provided the flexibility to use the most appropriate world view for the system being studied. this improved upon the more traditional situation in which simulation modelers were restricted to the modeling perspective embodied in the language they were using.  the success of this new approach was readily apparent.  jean j. o'reilly a. alan b. pritsker
second-order surface analysis using hybrid symbolic and numeric operators  results from analyzing the curvature of a surface can be used to improve the implementation, efficiency, and effectiveness of manufacturing and visualization of sculptured surfaces.  we develop a robust method using hybrid symbolic and numeric operators to create trimmed surfaces, each of which is solely convex, concave, or saddle and partitions the original surface. the same method is also used to identify regions whose curvature lies within prespecified bounds.  gershon elber elaine cohen
anaphora resolution in the extraction of treatment history language from court opinions by partial parsing  this paper describes an information extraction system that identifies and analyzes statements in court opinions regarding the value of cited cases as precedents. the system employs partial parsing techniques in conjunction with a semantic grammar to identify the language associated with such rulings. the most novel aspect of the system lies in its anaphora resolution module that combines syntactic, semantic, and domain-specific inference rules with local discourse information to link such language to case references.  khalid al-kofahi brian grom peter jackson
seeing the forest for the trees: hierarchical displays of hypertext structures  most recent hypertext systems support hierarchy only as a restricted subset of directed graph structure. consequently they do not provide many of the capabilities for graphical information hiding and structure manipulation that a tree makes possible. this paper describes display techniques developed for igd, a hypertext system that supports the creation of large graphical documents whose arbitrary directed graph structure is embedded in a strict hierarchy. igd offers the full generality of arbitrary keyworded links, while simultaneously allowing hierarchies to be easily manipulated and displayed with much of their structural detail selectively abstracted.  steven feiner
a qualitative simulation approach for fuzzy dynamical models  this article deals with simulation of approximate models of dynamic systems. we propose an approach that is appropriate when the uncertainty intrinsic in some models cannot be reduced by traditional identification techniques, due to the impossibility of gathering experimental data about the system itself. the article presents a methodology for qualitative modeling and simulation of approximately known systems. the proposed solution is based on the fuzzy sets theory, extending the power of traditional numerical-logical methods. we have implemented a fuzzy simulator that integrates a fuzzy, qualitative approach and traditional, quantitative methods.  andrea bonarini gianluca bontempi
a performance study of the cancelback protocol for time warp  this work presents results from an experimental evaluation of the space-time tradeoffs in time warp augmented with the cancelback protocol for memory management. an implementation of the cancelback protocol on time warp is described that executes on a shared memory multiprocessor, a 32 processor kendall square research machine (ksr1). the implementation supports canceling back more than one object when memory has been exhausted. the limited memory performance of the system is evaluated for three different workloads with varying degrees of symmetry. these workloads provide interesting stress cases for evaluating limited memory behavior. we, however, make certain simplifying assumptions (e.g., uniform memory requirement by all the events in the system) to keep the experiments tractable. the experiments are extensively monitored to determine the extent to which various overheads affect performance. it is observed that (i) depending on the available memory and asymmetry in the workload, canceling back several (called the salvage parameter) events at one time may improve performance significantly, by reducing certain overheads, (ii) a performance nearly equivalent to that with unlimited memory can be achieved with only a modest amount of memory depending on the degree of asymmetry in the workload.  samir r. das richard m. fujimoto
the holodeck ray cache: an interactive rendering system for global illumination in nondiffuse environments  we present a new method for rendering complex environments using interactive, progressive, view- independent, parallel ray tracing. a four-dimensional holodeck data structure serves as a rendering target and caching mechanism for interactive walk-throughs of nondiffuse environments with full global illumination. ray sample density varies locally according to need, and on- demand ray computation is supported in a parallel implementation. the holodeck file is stored on disk and cached in memory by a server using a least- recently-used (lru) beam-replacement strategy. the holodeck server coordinates separate ray evaluation and display processes, optimizing disk and memory usage. different display systems are supported by specialized drivers, which handle display rendering, user interaction, and input. the display driver creates an image from ray samples sent by the server and permits the manipulation of local objects, which are rendered dynamically using approximate lighting computed from holodeck samples. the overall method overcomes many of the conventionl limits of interactive rendering in scenes with complex surface geometry and reflectance properties, through an effective combination of ray tracing, caching, and hardware rendering.  gregory ward maryann simmons
the role of computer simulation in the development of a new elevator product  this paper discusses a new elevator dispatching strategy called advanced traffic management (or atm). a substantial computer simulation effort proved to be a major influence in the development of this new product for introduction to the marketplace. a simplified version of atm will be presented, and the simulation modeling process will be outlined. the main contributions of the simulation effort were in initial product verification and in design improvements resulting in increased u.s. patent protection.  bruce a. powell
case-based learning in inductive inference  there is proposed a formalization of case-based learning in terms of recursion-theoretic inductive inference. this approach is directly derived from some recently published case-based learning algorithms. the intention of the present paper is to exhibit the relationship between case-based learning and inductive inference and to specify this relation with mathematical precision. in particular, it is the author's intention to invoke inductive inference results for pointing to the crucial questions in case-based learning which allow to improve the power of case-based learning algorithms considerably. there are formalized several approaches to case-based learning. first, they vary in the way of presenting cases to a learning algorithm. second, they are different with respect to the underlying semantics of case bases together with similarity measures. third, they are distinguished by the flexibility in using similarity functions. the investigations presented relate the introduced learning types to identification types in recursion-theoretic inductive inference.  klaus p. jantke
function design document: toward better documentation for data processing contracts  discussions of data processing contracts often emphasize the goals of: 1)negotiating the best possible deal; and, 2) protecting the parties in case of dispute. considering the expense, delay and frustration wrought by disputes, especially when litigation results, an equally valuable goal is the preparation of contracts in such a way as to avoid disputes.  the author proposes that this goal be furthered by development of a documentation standard, to be known for purposes of this discussion as a "function design document" (fdd). the fdd would be produced before a contract for software services & products (ss & p)1 was entered into. the fdd would ideally require both parties to clearly define the functionality of the particular ss & p. a contract could then be entered into under which each party knew its own obligations as well as the expectations of the other party.  consideration is also given to the way in which the fdd should be handled, from a legal standpoint, since the possibility of a dispute cannot be ignored.  steven brower