waashk/acm huggingface dataset:
mapping communicative goals into conceptual tasks to generate graphics in discourse  we address the problem of realizing communicative plans in graphics. our approach calls for mapping communicative goals to conceptual tasks and then using task-based graphic design for selecting graphical techniques. in this paper, we present the mapping rules in several dimensions: data aggregation and selection, task synthesis, and task aggregation. those rules have been incorporated in autobrief, a research system for multimedia explanation.  stephan kerpedjiev steven f. roth
spectral processing of point-sampled geometry  we present a new framework for processing point-sampled objects using spectral methods. by establishing a concept of local frequencies on geometry, we introduce a versatile spectral representation that provides a rich repository of signal processing algorithms. based on an adaptive tesselation of the model surface into regularly resampled displacement fields, our method computes a set of windowed fourier transforms creating a spectral decomposition of the model. direct analysis and manipulation of the spectral coefficients supports effective filtering, resampling, power spectrum analysis and local error control. our algorithms operate directly on points and normals, requiring no vertex connectivity information. they are computationally efficient, robust and amenable to hardware acceleration. we demonstrate the performance of our framework on a selection of example applications including noise removal, enhancement, restoration and subsampling.  mark pauly markus gross
surface splatting  modern laser range and optical scanners need rendering techniques that can handle millions of points with high resolution textures. this paper describes a point rendering and texture filtering technique called _surface splatting_ which directly renders opaque and transparent surfaces from point clouds without connectivity. it is based on a novel screen space formulation of the elliptical weighted average (ewa) filter. our rigorous mathematical analysis extends the texture resampling framework of heckbert to irregularly spaced point samples. to render the points, we develop a surface splat primitive that implements the screen space ewa filter. moreover, we show how to optimally sample image and procedural textures to irregular point data during pre- processing. we also compare the optimal algorithm with a more efficient view- independent ewa pre- filter. surface splatting makes the benefits of ewa texture filtering available to point-based rendering. it provides high quality anisotropic texture filtering, hidden surface removal, edge anti-aliasing, and order- independent transparency.  matthias zwicker hanspeter pfister jeroen van baar markus gross
the rgyb color geometry  background:  the gamut of a color crt is defined by its three primary colors, each produced by a phosphor/electron gun combination. light from the primaries combines additively, so the color gamut is a subset of a three dimensional vector space [1]. with the primaries as basis vectors normalized to 1.0, the color gamut is a unit cube, known as the rgb color geometry, since the three primaries are usually red, green, and blue. user interaction via rgb is generally thought to be counterintuitive, and transformations of rgb, such as smith's hsv geometry [10] which is derived from centuries old artists' models [2], are more popular. more recent color theories, based on psychophysical and physiological models of early visual processing, suggest that more intuitive geometries may be possible.  the rgyb geometry is based on two recent discoveries about the human visual system. first, the three color signals from the cone receptors are organized into three opponent channels [1, 7]. a single achromatic channel indicates lightness or brightness. two chromatic channels, red/green and yellow/blue, signal the chromatic quantities. second, signals on the achromatic channel are easily distinguishable from signals on the chromatic ones [6]. consequently, it is usual to represent colors as a set of surfaces of colors that vary in chromaticity, each at a different level of brightness. examples are as diverse as cie chromaticity coordinates, the cieluv uniform color space, the munsell color system, and computer graphics color spaces such as hsv and hls [10, 12].  colin ware william cowan
bankxx: a program to generate argument through case-base research  in this paper we describe a system, called bankxx, which generates arguments by performing a heuristic best-first search of a highly interconnected network of legal knowledge. the legal knowledge includes cases represented from a variety of points of view---cases as collections of facts, cases as dimensionally- analyzed fact situations, cases as bundles of citations, and cases as prototypical factual scripts---as well as legal theories represented in terms of domain factors. bankxx performs its search for useful information using one of three evaluation functions encoded at different levels of abstraction: the domain level, an "argument-piece" level, and the overall argument level. evaluation at the domain level uses easily accessible information about the nodes, such as their type; evaluation at the argument- piece level uses information about generally useful components of case-based argument, such as best cases and supporting legal theories; evaluation at the overall-argument level uses factors, called argument dimensions, which address the overall substance and quality of an argument, such as the centrality of its supporting cases or the success record of its best theory. bankxx is instantiated in the area of personal bankruptcy governed by chapter 13 of the u.s. bankruptcy code, which permits a debtor to be discharged from debts through completion of a court-approved payment plan. in particular, our system addresses the requirement that such chapter 13 plans be "proposed in good faith."  edwina l. rissland david b. skalak m. timur friedman
isosurface extraction in time-varying fields using a temporal branch-on-need tree (t-bon)  the temporal branch-on-need tree (t-bon) extends the three-dimensional branch- on-need octree for time-varying isosurface extraction. at each time step, only those portions of the tree and data necessary to construct the current isosurface are read from disk. this algorithm can thus exploit the temporal locality of the isosurface and, as a geometric technique, spatial locality between cells in order to improve performance. experimental results demonstrate the performance gained and memory overhead saved using this technique.  philip sutton charles d. hansen
computation of the axial view of a set of isothetic parallelepipeds  we present a new technique to display a scene of three-dimensional isothetic parallelepipeds (3d-rectangles), viewed from infinity along one of the coordinate axes (axial view). in this situation, there always exists a topological sorting of the 3d-rectangles based on the relation of occlusion (a dominance relation). the arising total order is used to generate the axial view, where the two-dimensional view of each 3d-rectangle is incrementally added, starting from the closest 3d-rectangle. the proposed scene-sensitive algorithm runs in time o(n log2n \\+ d log n), where n is the number of 3d-rectangles and d is the number of edges of the display. this improves over the previously best known technique based on the same approach.  franco p. preparata jeffrey s. vitter mariette yvinec
measuring and predicting visual fidelity  this paper is a study of techniques for measuring and predicting visual fidelity. as visual stimuli we use polygonal models, and vary their fidelity with two different model simplification algorithms. we also group the stimuli into two object types: animals and man made artifacts. we examine three different experimental techniques for measuring these fidelity changes: naming times, ratings, and preferences. all the measures were sensitive to the type of simplification and level of simplification. however, the measures differed from one another in their response to object type. we also examine several automatic techniques for predicting these experimental measures, including techniques based on images and on the models themselves. automatic measures of fidelity were successful at predicting experimental ratings, less successful at predicting preferences, and largely failures at predicting naming times. we conclude with suggestions for use and improvement of the experimental and automatic measures of visual fidelity.  benjamin watson alinda friedman aaron mcgaffey
a logical approach to high-level agent control  recent work in animated human-like agent has made impressive progress toward generating agents with believable appearances and realistic motions for the interactive applications of inhabited virtual worlds. it remains difficult, however, to instruct animated agents to perform specific tasks or take initiatives. this paper addresses the challenge of instructability by introducing cognitive modelling - a novel logical approach based on a highly developed logical theory of actions, i. e. event calculus. cognitive models go beyond behavioural models in that they govern an agent's behaviour by reasoning about its knowledge, actions and events. to facilitate the construction of the language (bsl) from the event calculus formalism. using bsl, we can specify and agent's domain knowledge, design behaviour controllers and then control the agent's behaviour in terms of goals and/ or goals and/ or user's instructions. this approach allows agent's behaviours to be specified and controlled more naturally and intuitively, more succinctly and at a much highter level of abstraction than would otherwise be possible. it als provides a logical characterisation of planning via abductive reasoning process. furthermore, we integrate sensing capability into our underlying theoretical framework, thus enabling animated agents to generate appropriate behaviour even in complex, dynamic virtual worlds. an animated human- like interface agent for virtual environments is used to demonstrate the approach. the architecture for implementing the approach is also described.  l. chen k. bechkoum g. clapworthy
volume sculpting  we present a modeling technique based on the metaphor of interactively sculpting complex 3d objects from a solid material, such as a block of wood or marble. the 3d model is represented in a 3d raster of voxels where each voxel stores local material property information such as color and texture. sculpting is done by moving 3d voxel-based tools within the model. the affected regions are indicated directly on the 2d projected image of the 3d model. by reducing the complex operations between the 3d tool volume and the 3d model down to primitive voxel-by-voxel operations, coupled with the utilization of a localized ray casting for image updating, our sculpting tool achieves real-time interaction. furthermore, volume sampling techniques and volume manipulations are employed to ensure that the process of sculpting does not introduce aliasing into the models.  sidney w. wang arie e. kaufman
adaptive view dependent tessellation of displacement maps  displacement mapping is an effective technique for encoding the high levels of detail found in today's triangle based surface models. extending the hardware rendering pipeline to be capable of handling displacement maps as geometric primitives, will allow highly detailed models to be constructed without requiring large numbers of triangles to be passed from the cpu to the graphics pipeline. we present a new approach based on recursive tessellation that adapts to the surface complexity described by the displacement map. we also ensure that the resolution of the displaced mesh is tessellated with respect to the current view point. our tessellation scheme performs all tests only on triangle edges to avoid generating cracks on the displaced surface. the main decision for vertex insertion is based on two comparisons involving the average height surrounding the vertices and the normals at the vertices. individually, the tests will fail to tessellate a mesh satisfactorily, but their combination achieves good results.  we propose several additions to the typical hardware rendering pipeline in order to achieve displacement map rendering in hardware. the mesh tessellation is placed within the rendering pipeline so that we can take advantage of the pre-existing vertex transformation units to perform the setup calculations for our view dependent test. our method adds only simple arithmetic and comparison operations to the graphics pipeline and makes use of existing units for calculations wherever possible.  michael doggett johannes hirche
visualizing gridded datasets with large number of missing values (case study)  much of the research in scientific visualization has focused on complete sets of gridded data. this paper presents our experience dealing with gridded data sets with large number of missing or invalid data, and some of our experiments in addressing the shortcomings of standard off-the-shelf visualization algorithms. in particular, we discuss the options in modifying known algorithms to adjust to the specifics of sparse datasets, and provide a new technique to smooth out the side-effects of the operations. we apply our findings to data acquired from nexrad (next generation radars) weather radars, which usually have no more than 3 to 4 percent of all possible cell points filled.  suzana djurcilov alex pang
plenoptic sampling  this paper studies the problem of plenoptic sampling in image-based rendering (ibr). from a spectral analysis of light field signals and using the sampling theorem, we mathematically derive the analytical functions to determine the minimum sampling rate for light field rendering. the spectral support of a light field signal is bounded by the minimum and maximum depths only, no matter how complicated the spectral support might be because of depth variations in the scene. the minimum sampling rate for light field rendering is obtained by compacting the replicas of the spectral support of the sampled light field within the smallest interval. given the minimum and maximum depths, a reconstruction filter with an optimal and constant depth can be designed to achieve anti-aliased light field rendering.  plenoptic sampling goes beyond the minimum number of images needed for anti- aliased light field rendering. more significantly, it utilizes the scene depth information to determine the minimum sampling curve in the joint image and geometry space. the minimum sampling curve quantitatively describes the relationship among three key elements in ibr systems: scene complexity (geometrical and textural information), the number of image samples, and the output resolution. therefore, plenoptic sampling bridges the gap between image-based rendering and traditional geometry-based rendering. experimental results demonstrate the effectiveness of our approach.  jin-xiang chai shing-chow chan heung- yeung shum xin tong
an extension of manifold boundary representations to the r-sets  in this paper we study the relationship between manifold solids (r-sets whose boundaries are two-dimensional closed manifolds) and r-sets. we begin by showing that an r-set may be viewed as the limit of a certain sequence of manifold solids, where distance is measured using the hausdorff metric. this permits us to introduce a minimal set of generalized euler operators, sufficient for the construction and manipulation of r-sets. the completeness result for ordinary euler operators carries over immediately to the generalized euler operators on the r-sets and the modification of the usual boundary data structures, corresponding to our extension to nonmanifold r-sets, is straightforward. we in fact describe a modification of a well-known boundary data structure in order to illustrate how the extension can be used in typical solid modeling algorithms, and describe an implementation.  the results described above largely eliminate what has been called an inherent mismatch between the modeling spaces defined by manifold solids and by r-sets. we view the r-sets as a more appropriate choice for a modeling space: in particular, the r-sets provide closure with respect to regularized set operations and a complete set of generalized euler operators for the manipulation of boundary representations, for graphics and other purposes. it remains to formulate and prove a theorem on the soundness of the generalized euler operators.  h. desaulniers n. f. stewart
suitor: an attentive information system  attentive systems pay attention to what users do so that they can attend to what users need. such systems track user behavior, model user interests, and anticipate user desires and actions. because the general class of attentive systems is broad --- ranging from human butlers to web sites that profile users --- we have focused specifically on attentive information systems, which observe user actions with information resources, model user information states, and suggest information that might be helpful to users. in particular, we describe an implemented system, simple user interest tracker (suitor), that tracks computer users through multiple channels --- gaze, web browsing, application focus --- to determine their interests and to satisfy their information needs. by observing behavior and modeling users, suitor finds and displays potentially relevant information that is both timely and non- disruptive to the users' ongoing activities.  paul p. maglio rob barrett christopher s. campbell ted selker
navigating through a sea of information: an experiment in the development of an expert system for consulting questions  by mastering the ability to sail forth and navigate the seas, people have expanded their wealth and knowledge throughout the ages. the ability to sail forth, however, was greatly aided by the invention of navigational tools. today, we who work in centers of information dissemination are faced with a similar challenge---navigating through the sea of information that confronts us every day. like the early sailors, who had only a few crude instruments to guide them on their journeys, we, too, have had little to guide us through our extensive database of knowledge. although our destinations may not seem as exotic as the ancient ports-of-call, they are no less important in exploring knowledge and pushing back the frontiers of discovery.  arnold alagar
a calendar with common sense  digital devices today have little understanding of their real-world context, and as a result they often make stupid mistakes. to improve this situation we are developing a database of world knowledge called thoughttreasure at the same time that we develop intelligent applications. in this paper we present one such application, sensical, a calendar with a degree of common sense. we discuss the pieces of common sense important in calendar management and present methods for extracting relevant information from calendar items.  erik t. mueller
planning motions with intentions  we apply manipulation planning to computer animation. a new path planner is presented that automatically computes the collision-free trajectories for several cooperating arms to manipulate a movable object between two configurations. this implemented planner is capable of dealing with complicated tasks where regrasping is involved. in addition, we present a new inverse kinematics algorithm for the human arms. this algorithm is utilized by the planner for the generation of realistic human arm motions as they manipulate objects. we view our system as a tool for facilitating the production of animation.  yoshihito koga koichi kondo james kuffner jean-claude latombe
anisotropic nonlinear diffusion in flow visualization  many applications produce three-dimensional points that must be further processed to generate a surface. surface reconstruction algorithms that start with a set of unorganized points are extremely time-consuming. sometimes, however, points are generated such that there is additional information available to the reconstruction algorithm. we present spiraling edge, a specialized algorithm for surface reconstruction that is three orders of magnitude faster than algorithms for the general case. in addition to sample point locations, our algorithm starts with normal information and knowledge of each point's neighbors. our algorithm produces a localized approximation to the surface by creating a star-shaped triangulation between a point and a subset of its nearest neighbors. this surface patch is extended by locally triangulating each of the points along the edge of the patch. as each edge point is triangulated, it is removed from the edge and new edge points along the patch's edge are inserted in its place. the updated edge spirals out over the surface until the edge encounters a surface boundary and stops growing in that direction, or until the edge reduces to a small hole that is filled by the final triangle.  t. preußer m. rumpf
grouping and parameterizing irregularly spaced points for curve fitting  given a large set of irregularly spaced points in the plane, an algorithm for partitioning the points into subsets and fitting a parametric curve to each subset is described. the points could be measurements from a physical phenomenon, and the objective in this process could be to find patterns among the points and describe the phenomenon analytically. the points could be measurements from a geometric model, and the objective could be to reconstruct the model by a combination of parametric curves. the algorithm proposed here can be used in various applications, especially where given points are dense and noisy. examples demonstrating the behavior of the algorithm under noise and density of the points are presented and discussed.  a. ardeshir goshtasby
modeling the urban development process and the related transportation impacts  a conceptually realistic but highly idealized approach was taken to create a simulation model of the structural interactions between the many elements of urban land use and transportation decisions. the objective is to use the model to discover elements and links that are amenable to land use intensification policies. while land use decisions are based on system perspective, transportation decisions are individualized. while land use decisions are permanent, transportation decisions are susceptible to be influenced. through planning and other governmental policies, it is hoped that "infilling" can be achieved and the transportation conditions ensued will be energy efficient and environmentally compatible.  tenny n. lam richard corsi katherine wages
refutational proofs of geometry theorems via characteristic set computation  a refutational approach to geometry theorem proving using ritt-wu's algorithm for computing a characteristic set is discussed. a geometry problem is specified as a quantifier-free formula consisting of a finite set of hypotheses implying a conclusion, where each hypothesis is either a geometry relation or a subsidiary condition ruling out degenerate cases, and the conclusion is another geometry relation. the conclusion is negated, and each of the hypotheses (including the subsidiary conditions) and the negated conclusion is converted to a polynomial equation. characteristic set computation is used for checking the inconsistency of a finite set of polynomial equations over an algebraic closed field. the method is contrasted with a related refutational method that used buchberger's grobner basis algorithm for the inconsistency check.  d. kapur h. k. wan