waashk/acm huggingface dataset:
artificial fishes: physics, locomotion, perception, behavior  this paper proposes a framework for animation that can achieve the intricacy of motion evident in certain natural ecosystems with minimal input from the animator. the realistic appearance, movement, and behavior of individual animals, as well as the patterns of behavior evident in groups of animals fall within the scope of the framework. our approach to emulating this level of natural complexity is to model each animal holistically as an autonomous agent situated in its physical world. to demonstrate the approach, we develop a physics-based, virtual marine world. the world is inhabited by artificial fishes that can swim hydrodynamically in simulated water through the motor control of internal muscles that motivates fins. their repertoire of behaviors relies on their perception of the dynamic environment. as in nature, the detailed motions of artificial fishes in their virtual habitat are not entirely predictable because they are not scripted.  xiaoyuan tu demetri terzopoulos
taking advantage of models for legal classification  legal reasoning is often couched in terms of legal classification. we examine how three models of classification --- classical, probabilistic and exemplar --- are used to perform legal classification. we argue that all three models of classification are implicitly applied by existing ai methods. the cabaret ("case-based reasoning tool") system is suggested as an architecture that applies all three models. the relative difficulty of revising knowledge in rule form, in hypo- style dimension form, and exemplar form is considered.  d. b. skalak
computer-based readability indexes  computer-based document preparation systems provide many aids to the production of quality documents. a text editor allows arbitrary text to be entered and modified. a text formatter then imposes defined rules on the form of the text. a spelling checker ensures that each word is a correctly spelled word. none of these aids, however, affect the meaning of the document; the document may be well-formatted and correctly spelled but still incomprehensible.  douglas r. mccallum james l. peterson
computers aid index and glossary preparation  i have written many books but only in the past two years have i had available my own computer and word processor. now i find the word processor indispensible to my writing endeavors. but my computer can do more than just compose the manuscript. it can help me to compile and organize indexes and glossaries. i have just finished three books and i got assistance from my computer on all of them for the indexes.  there are four kinds of things my computer does for me:  1\\. extracts information directly from the manuscript, providing important words i might want to index;  2\\. helps me to make an index file;  3\\. puts this file in alphabetic order;  4\\. prints out the index in the desired format.  some of the help i get is from program packages which i purchase. other help i get from basic programs which i have written to assist me further. i have not seen many articles which describe how to combine purchased software with your programs to facilitate a unified activity.  first i will describe the system that i have and how i am using it. then i will tell you what i wanted done in terms of indexes. finally i will give you the details of the programs i have written and how i use the packages that you can buy.  ivan flores
a software test-bed for the development of 3-d raster graphics systems  we describe a set of utility routines for 3-d shaded display which allow us to create raster scan display systems for various experimental and production applications. the principal feature of this system is a flexible scan conversion processor that can simultaneously manage several different object types.  communications between the scan conversion routine and processes which follow it in the display pipeline can be routed through a structure called a "span buffer" which retains some of the high resolution, three dimensional data of the object description and at the same time has the characteristics of a run length encoded image.  turner whitted david m. weimer
hierarchical multi-agent reinforcement learning  in this paper we investigate the use of hierarchical reinforcement learning to speed up the acquisition of cooperative multi-agent tasks. we extend the maxq framework to the multi-agent case. each agent uses the same maxq hierarchy to decompose a task into sub-tasks. learning is decentralized, with each agent learning three interrelated skills: how to perform subtasks, which order to do them in, and how to coordinate with other agents. coordination skills among agents are learned by using joint actions at the highest level(s) of the hierarchy. the q nodes at the highest level(s) of the hierarchy are configured to represent the joint task-action space among multiple agents. in this approach, each agent only knows what other agents are doing at the level of sub-tasks, and is unaware of lower level (primitive) actions. this hierarchical approach allows agents to learn coordination faster by sharing information at the level of sub-tasks, rather than attempting to learn coordination taking into account primitive joint state-action values. we apply this hierarchical multi-agent reinforcement learning algorithm to a complex agv scheduling task and compare its performance and speed with other learning approaches, including flat multi-agent, single agent using maxq, selfish multiple agents using maxq (where each agent acts independently without communicating with the other agents), as well as several well-known agv heuristics like "first come first serve", "highest queue first" and "nearest station first". we also compare the tradeoffs in learning speed vs. performance of modeling joint action values at multiple levels in the maxq hierarchy.  rajbala makar sridhar mahadevan mohammad ghavamzadeh
interactive modeling and simulation of transaction flow or network models using the ada simulation support environment  the ada simulation support environment (asse) is a software system, with the purpose to support the development and maintenance of simulation models written in ada throughout their life cycle. we describe here the transaction flow or network part of the asse, which allows to build models like in gpss or slam. our view of such models is slightly different from that of the above mentioned languages, which is demonstrated in detail by the server/resource process. the design stresses modular top-down development using submodels. models can be developed and tested interactively.  heimo h. adelsberger
a more flexible image generation environment  a supervisory process is used to distribute picture-generation tasks to heterogeneous subprocesses. significant advantages accrue by tailoring the subprocesses to their tasks. in particular, scan conversion algorithms tailored to different surface types may be used in the same image, a changing mixture of processors is possible, and, by multiprogramming, a single processor may be used more effectively. a two- level shape data structure supports this execution environment, allowing top- level priority decisions which avoid comparisons between surface elements from non-interfering objects during image construction.  f. c. crow
expression cloning  we present a novel approach to producing facial expression animations for new models. instead of creating new facial animations from scratch for each new model created, we take advantage of existing animation data in the form of vertex motion vectors. our method allows animations created by any tools or methods to be easily retargeted to new models. we call this process _expression cloning_ and it provides a new alternative for creating facial animations for character models. expression cloning makes it meaningful to compile a high-quality facial animation library since this data can be reused for new models. our method transfers vertex motion vectors from a source face model to a target model having different geometric proportions and mesh structure (vertex number and connectivity). with the aid of an automated heuristic correspondence search, expression cloning typically requires a user to select fewer than ten points in the model. cloned expression animations preserve the relative motions, dynamics, and character of the original facial animations.  jun-yong noh ulrich neumann
environment matting extensions: towards higher accuracy and real-time capture  environment matting is a generalization of traditional bluescreen matting. by photographing an object in front of a sequence of structured light backdrops, a set of approximate light-transport paths through the object can be computed. the original environment matting research chose a middle ground \---using a moderate number of photographs to produce results that were reasonably accurate for many objects. in this work, we extend the technique in two opposite directions: recovering a more accurate model at the expense of using additional structured light backdrops, and obtaining a simplified matte using just a single backdrop. the first extension allows for the capture of complex and subtle interactions of light with objects, while the second allows for video capture of colorless objects in motion.  yung-yu chuang douglas e. zongker joel hindorff brian curless david h. salesin richard szeliski
prime rule-based methodologies give inadequate control  the use of rule-based methodologies in the development of expert systems is widespread. in order to provide good explanations in these systems it is desirable that the rules be prime. the difficulty of expressing control in such rules, and thus arriving at a desirable sequencing of events, has led to pragmatic additions to the basic methodology. recent developments in the theory of decision processes have provided new insight into the form of a desirable sequencing. prime rules, even when augmented by sophisticated control strategies, cannot generate from backward chaining all these desirable sequencings. furthermore, if one of these desirable sequencings happens to be generated from prime rules it may be by luck rather than design.  j r b cockett j herrera
a triangulation algorithm from arbitrary shaped multiple planar contours  conventional triangulation algorithms from planar contours suffer from some limitations. for instance, incorrect results can be obtained when the contours are not convex, or when the contours in two successive slices are very different. in the same way, the presence of multiple contours in a slice leads to ambiguities in defining the appropriate links. the purpose of this paper is to define a general triangulation procedure that provides a solution to these problems. we first describe a simple heuristic triangulation algorithm which is extended to nonconvex contours. it uses an original decomposition of an arbitrary contour into elementary convex subcontours. then the problem of linking one contour in a slice to several contours in an adjacent slice is examined. to this end, a new and unique interpolated contour is generated between the two slices, and the link is created using the previously defined procedure. next, a solution to the general case of linking multiple contours in each slice is proposed. finally, the algorithm is applied to the reconstitution of the external surface of a complex shaped object: a human vertebra.  a. b. ekoule f. c. peyrin c. l. odet
issue spotting in legal cases  for any system that uses previous experience to solve problems in new situations, it is necessary to identify the features in the situation that should match features in the previous cases through some process of situation analysis. in this paper, we examine as issue spotting; in particular, we present how issues spotting is implemented in chaser, a legal reasoning system that works in the domain of tort law.  the approach presented here is a compromise between generality and efficiency, and is applicable to a range of problems and domains outside of legal reasoning. in particular, it presents a principled way to use multiple cases for a single problem by exploiting the inherent structure present in many domains.  barbara cuthill robert mccartney
radiosity and hybrid methods  we examine various solutions to the global illumination problem, based on an exact mathematical analysis of the rendering equation. in addition to introducing efficient radiosity algorithms, we present a uniform approach to reformulate all of the basic radiosity equations used so far. using hybrid methods we are able to analyze possible combinations of the view-dependent ray-tracing method and of the low- resolution radiosity-based method, and to offer new algorithms.  laszlo neumann attila neumann
animating explosions  in this paper, we introduce techniques for animating explosions and their effects. the primary effect of an explosion is a disturbance that causes a shock wave to propagate through the surrounding medium. the disturbance determines the behavior of nearly all other secondary effects seen in explosion. we simulate the propagation of an explosion through the surrounding air using a computational fluid dynamics model based on the equations for compressible, viscous flow. to model the numerically stable formation of shocks along blast wave fronts, we employ an integration method that can handle steep pressure gradients without introducing inappropriate damping. the system includes two-way coupling between solid objects and surrounding fluid. using this technique, we can generate a variety of effects including shaped explosive charges, a projectile propelled from a chamber by an explosion, and objects damaged by a blast. with appropriate rendering techniques, our explosion model can be used to create such visual effects as fireballs, dust clouds, and the refraction of light caused by a blast wave.  gary d. yngve james f. o'brien jessica k. hodgins
image-based modeling and photo editing  we present an image-based modeling and editing system that takes a single photo as input. we represent a scene as a layered collection of depth images, where each pixel encodes both color and depth. starting from an input image, we employ a suite of user- assisted techniques, based on a painting metaphor, to assign depths and extract layers. we introduce two specific editing operations. the first, a "clone brushing tool," permits the distortion-free copying of parts of a picture, by using a parameterization optimization technique. the second, a "texture-illuminance decoupling filter," discounts the effect of illumination on uniformly textured areas, by decoupling large- and small-scale features via bilateral filtering. our system enables editing from different viewpoints, extracting and grouping of image- based objects, and modifying the shape, color, and illumination of these objects.  byong mok oh max chen julie dorsey fredo durand
computer-generated pen-and-ink illustration  this paper describes the principles of traditional pen-and-ink illustration, and shows how a great number of them can be implemented as part of an automated rendering system. it introduces "stroke textures," which can be used for achieving both texture and tone with line drawing. stroke textures also allow resolution-dependent rendering, in which the choice of strokes used in an illustration is appropriately tied to the resolution of the target medium. we demonstrate these techniques using complex architectural models, including frank lloyd wright's "robie house."  georges winkenbach david h. salesin
state event in combined simulation  within the context of combined (discrete and continuous) simulation, modelers attribute considerable importance to the concept of state event representation. unfortunately, since the methodology introduced in gasp iv, little research efforts have been devoted to the development of a more flexible and a more powerful modelling tool for representation of state event within a support system for model development environment. this paper briefly reviews the existing methodology and suggests a new approach useful for representation of a state event triggered by a complex condition involving two or more continuously changing attributes.  irma angulo gholamreza torkzadeh
dab: interactive haptic painting with 3d virtual brushes  _we present a novel painting system with an intuitive haptic interface, which serves as an expressive vehicle for interactively creating painterly works. we introduce a deformable, 3d brush model, which gives the user natural control of complex brush strokes. the force feedback enhances the sense of realism and provides tactile cues that enable the user to better manipulate the paint brush. we have also developed a bidirectional, two-layer paint model that, combined with a palette interface, enables easy loading of complex blends onto our 3d virtual brushes to generate interesting paint effects on the canvas. the resulting system, dab, provides the user with an artistic setting, which is conceptually equivalent to a real-world painting environment. several users have tested dab and were able to start creating original art work within minutes._  bill baxter vincent scheib ming c. lin dinesh manocha
scanline rendering of parametric surfaces  a scanline algorithm is described which renders bicubic patches directly from the parametric description without producing a polygonal approximation. the algorithm is partially based on earlier work by whitted. a primitive object, called a "curved-edge polygon", is defined, and an algorithm for breaking down a bicubic patch into the primitive objects is described. a general surface intersection method is employed to provide a robust silhouette edge detector. shades are computed by calculating a cubic approximation to the normal surface and performing either a cubic or a linear interpolation of the bounding edge normals across the scanline. subdivision of parametric surfaces is used to reduce the complexity of the surfaces being rendered, providing dramatic improvement in the results of both the silhouette detector and the shading methods.  dino schweitzer elizabeth s. cobb
experimenting and theorizing in theory formation  the bacon system, developed by langley, simon and bradshaw, has shown the utility of a data driven discovery system. a new system, called fahrenheit, has been built which extends bacon, making it more robust and allowing it perform a wider range of discovery activity. the new system extends bacon in several ways: 1) it determines the scope of a law by making simulated experiments, and by searching for regularities that describe the scope boundaries. 2) the world model in which the experiments are performed is more sophisticated. 3) the order in which the data are considered is placed under the control of fahrenheit so that the system continues the discovery process even if no regularity is found for a particular variable.  b w koehn j m zytkow
model-based fault diagnosis: knowledge acquisition and system design  within this paper a model-based approach for knowledge-based diagnosis-systems is discussed. the model is derived from the fault recognition and fault searching techniques used by maintenance experts in general. the presented model has implications on the knowledge acquisition method in a way that only such data that are usually known to the maintenance expert have to be gathered and interlinked. this means that knowledge acquisition has only to deal with a knowledge source that can be prestructured. the model for knowledge-based diagnosis-systems and the knowledge acquisition method has been successfully used to develop diagnosis systems for a smd-insertion machine and an extrusion machine. time needed for knowledge acquistion has been reduced.  thomas h. schmidt
hmds, caves & chameleon: a human-centric analysis of interaction in virtual space there are a various approaches to implementing virtual reality (vr) systems. the head mounted display (hmd) and cave approaches are two of the best known. in this paper, we discuss such approaches from the perspective of the types of interaction that they afford. our analysis looks at interaction from three perspectives: solo interaction, collaborative interaction in the same physical space and remote collaboration. from this analysis emerges a basic taxonomy that is intended to help systems designers make choices that better match their implementation with the needs of their application and users. bill buxton george w. fitzmaurice
preventing existence we discuss the treatment of prevention statements in both naturallanguage semantics and knowledge representation, with particularregard to existence entailments. first order representations withan explicit existence predicate are shown to not adequately capturethe entailments of prevention statements. a linguistic analysis isframed in a higher order intensional logic, employing a fregeannotion of existence as instantiation of a concept. we discuss howthis can be mapped to a cyc style knowledge representation. cleo condoravdi dick crouch john everett valeria paiva reinhard stolle danny bobrow martin van den berg
on the isomorphism problem for finite-dimensional binomial algebras  binomial algebras are finitely presented algebras defined by monomials or binomials. given two binomial algebras, one important problem is to decide whether or not they are isomorphic as algebras. we study an algorithm for solving this problem, when both algebras are finite-dimensional over a field. in particular, when they are monomial algebras (i.e. binomial algebras defined by monomials only), the problem has already been completely solved by the presentation uniqueness.  in this paper, we provide some necessary conditions in terms of partially ordered sets for two certain binomial algebras to be isomorphic. in other words, invariants of the binomial algebras are presented. these conditions together serve as an effective procedure for solving the isomorphism problem.  k. shirayanagi
a family of new algorithms for soft filling  soft filling algorithms change the color of an anti-aliased region, maintaining the anti-aliasing of the region. the two published algorithms for soft filling work only if the foreground region is anti-aliased against a black background. this paper presents three new algorithms. the first fills against a region consisting of any two distinct colors, and is faster than the published algorithms on a pixel-by-pixel basis for an rgb frame buffer; the second fills against a region composed of three distinct colors; and the third fills against a region composed of four distinct colors. as the power of the algorithms increases, so do the number of assumptions they make, and the computational cost.  kenneth p. fishkin brian a. barsky
spatiotemporal sensitivity and visual attention for efficient rendering of dynamic environments  we present a method to accelerate global illumination computation in prerendered animations by taking advantage of limitations of the human visual system. a spatiotemporal error tolerance map, constructed from psychophysical data based on velocity dependent contrast sensitivity, is used to accelerate rendering. the error map is augmented by a model of visual attention in order to account for the tracking behavior of the eye. perceptual acceleration combined with good sampling protocols provide a global illumination solution feasible for use in animation. results indicate an order of magnitude improvement in computational speed.  hector yee sumanita pattanaik donald p. greenberg