waashk/acm huggingface dataset:
graphics growth at clemson university  interest in computer graphics has been steadily growing at clemson university and has led to a very rapid expansion of graphics hardware and software. this paper is divided into four parts:  • the history of our graphics hardware acquisitions with comments about the advantages and disadvantages of particular devices.  • a discussion of software that runs on our system from the perspective of how it shaped our growth.  • a discussion of the amount of resources dedicated by academic computing support (acs, our user support group) to graphics.  • a discussion of future growth.  gabriel acebo
object recognition through automated tactile sensing (abstract only)  convex polyhedra were modelled as generalized cylinders (gcs) and programs were written to recognize them through single-sensor tactile exploration. the system was designed to recognize objects that vary in size and orientation. the sensor for which the programs were written is the lord corp. lts-200, which has a flat 16 by 10 array of sensors and a flexible "skin". from a sensor impression the software can recognize lines, corners, and edges. these features are used to guide exploration and to construct representations of polyhedron faces. a gc is constructed from descriptions of faces on opposite sides of the object, the gc description includes face descriptions, the axis length, the sweeping rule, and the degree of tilt of the axis relative to the faces. a list of standard gc descriptions is searched to make an identification. the procedures have been tested with simulated tactile impressions to discover the tolerance of the system for noise. tests on real tactile input are in progress.  this work is supported by nsf grant ecs-8216572 to case western reserve university.  william mcmillan
summed-area tables for texture mapping  texture-map computations can be made tractable through use of precalculated tables which allow computational costs independent of the texture density. the first example of this technique, the "mip" map, uses a set of tables containing successively lower-resolution representations filtered down from the discrete texture function. an alternative method using a single table of values representing the integral over the texture function rather than the function itself may yield superior results at similar cost. the necessary algorithms to support the new technique are explained. finally, the cost and performance of the new technique is compared to previous techniques.  franklin c. crow
topologically reliable display of algebraic curves  an algebraic curve is a set of points in the plane satisfying an equation f(x,y) 0, where f(x,y) is a polynomial in x and y with rational number coefficients. the topological structure of an algebraic curve can be complicated. it may, for example, have multiple components, isolated points, or intricate self-crossings. in the field of computer algebra (symbolic mathematical computation), algorithms for exact computations on polynomials with rational number coefficients have been developed. in particular, the cylindrical algebraic decomposition (cad) algorithm of computer algebra determines the topological structure of an algebraic curve, given f(x,y) as input. we describe methods for algebraic curve display which, by making use of the cad algorithm, correctly portray the topological structure of the curve. the running times of our algorithms consist almost entirely of the time required for the cad algorithm, which varies from seconds to hours depending on the particular f(x,y).  dennis s. arnon
requirements for machine learning in expert systems (abstract)  as dietterich pointed out at the 1989 machine learning workshop, the field needs analyses of the kinds of tasks that require machine learning (ml), and of the suitability of existing ml techniques for solving real problems. an area often mentioned as one that would benefit from ml is that of expert systems. learning from experience could alleviate the knowledge acquisition "bottleneck". although there have been some impressive successes in learning practical knowledge from examples, existing ml techniques lack the power to learn to conduct different phases of an expert "consultation". there are usually many dozens of variables to consider in an expert task, and their relevance changes as the consultation evolves. ml systems such as id3, aq11, and neural networks bog down quickly as extraneous variables are introduced. it is not practical to submit all data derived from an example consultation to such programs, expecting them to produce monolithic knowledge structures. based on our work in developing a diagnostic expert system, we offer suggestions for future work in ml. one is that the system be given knowledge that is easily available from a human expert. the ml program should be given a "proto-rule" for a specific decision, indicating the most relevant variables to be used by the rule and its "roughcut" logic. such knowledge can be gotten from an expert quickly. ml routines can then edit the logic and consider other variables as examples are considered. search is reduced drastically. other suggestions include ways to combine ml techniques.  christopher j. gardiner william w. mcmillan
learning with queries but incomplete information (extended abstract)  we investigate learning with membership and equivalence queries assuming that the information provided to the learner is incomplete. by incomplete we mean that some of the membership queries may be answered by "i don't know." this model is a worst-case version of the incomplete membership query model of angluin and slonim. it attempts to model practical learning situations, including an experiment of lang and baum that we describe, where the teacher may be unable to answer reliably some queries that are critical for the learning algorithm.  we present algorithms to learn monotone k-term dnf with membership queries only, and to learn monotone dnf with membership and equivalence queries. compared to the complete information case, the query complexity increases by an additive term linear in the number of "i don't know" answers received. we also observe that the blowup in the number of queries can in general be exponential for both our new model and the incomplete membership model.  robert h. sloan györgy turán
geometric compression through topological surgery  the abundance and importance of complex 3-d data bases in major industry segments, the affordability of interactive 3-d rendering for office and consumer use, and the exploitation of the internet to distribute and share 3-d data have intensified the need for an effective 3-d geometric compression technique that would significantly reduce the time required to transmit 3-d models over digital communication channels, and the amount of memory or disk space required to store the models. because the prevalent representation of 3-d models for graphics purposes is polyhedral and because polyhedral models are in general triangulated for rendering, this article introduces a new compressed representation for complex triangulated models and simple, yet efficient, compression and decompression algorithms. in this scheme, vertex positions are quantized within the desired accuracy, a vertex spanning tree is used to predict the position of each vertex from 2,3, or 4 of its ancestors in the tree, and the correction vectors are entropy encoded. properties, such as normals, colors, and texture coordinates, are compressed in a similar manner. the connectivity is encoded with no loss of information to an average of less than two bits per triangle. the vertex spanning tree and a small set of jump edges are used to split the model into a simple polygon. a triangle spanning tree and a sequence of marching bits are used to encode the triangulation of the polygon. our approach improves on michael deering's pioneering results by exploiting the geometric coherence of several ancestors in the vertex spanning tree, preserving the connectivity with no loss of information, avoiding vertex repetitions, and using about three fewer bits for the connectivity. however, since decompression requires random access to all vertices, this method must be modified for hardware rendering with limited onboard memory. finally, we demonstrate implementation results for a variety of vrml models with up to two orders of magnitude compression.  gabriel taubin jarek rossignac
discrete-event simulation and the event horizon  the event horizon is a very important concept that is useful for both parallel and sequential discrete-event simulations. by exploiting the event horizon, parallel simulations can process events in a manner that is risk-free (i.e., no antimessages) in adaptable "breathing" time cycles with variable time widths. additionally, exploiting the event horizon can greatly reduce the event list management overhead that is common to virtually all discrete-event simulations.  this paper develops an analytic model describing the event horizon from first principles using equilibrium considerations and the hold model (where each event, when consumed, generates a single new event with future-time statistics described by a known probability function). exponential and beta-density functions are used to verify the mathematics presented in this paper.  jeff s. steinman
esplex: a rule and conceptual model for representing statutes  the characteristics of the esplex system which may be defined as a "rule and conceptual based model" are illustrated, together with the possibilities for its utilization, its similarities with other existing projects, and the requisites of the knowledge representation language.  the methodology and the theoretical propositions that have led to the definition of the representation language are therefore explained. the characteristics of the system which manages the knowledge base are also described and a brief comment is made regarding future development.  c. biagioli p. mariani d. tiscornia
graphics standards for three-dimensional modelling  much effort has been spent in defining a standard call interface for a library of routines with display primitives embedded in a three-dimensional space. this paper argues that this is now an inappropriate target. there is too much diversity in the three-dimensional things we want to draw and in the kinds of picture we want to draw of them for any single standard to be both broadly acceptable and specifically useful.  if the decision is made to go for a set of specialized standards for wire frame and for rendered graphics for data presentation, for sculptured surfaces and for object models, it becomes apparent that far more can be gained from a higher level standard, at the data presentation or object modelling level.  in the object modelling community, at least, there is indeed work toward such a standard based on the iges proposals. this has very few concepts in common with the graphics standard effort, and it is not clear at present what contribution the graphics community has to make in this area.  the suggestion made here is that there may well be a number of paragraphs or sections common to more than one of the graphics-related and higher level standards. one such is the coordinate transformation (the dreaded 4 × 4 matrix). its definition and its use both for modelling and viewing concepts are suggested which resolve some of the black art associated with transformation in the past. these could become the conceptual basis for a short simple standard in this area.  malcolm sabin
three-dimensional beans - creating web content using 3d components in a 3d authoring environment  this paper deals with the question how the component idea can be transferred to the authoring of 3d content for the www. the concept of 3d beans and their according authoring environment is presented. in addition, an implementation of this concept using java3d and java beans is described. advantages of the concept are discussed and illustrated with an application example from the area of computer-based training. major advantages of the 3d beans concept are on the one hand that 3d content can be created in a virtual environment more directly and efficiently using pre-fabricated components that fit together. especially, as the author is supported by a bean authoring environment that itself uses information from the 3d beans. on the other hand, a 3d authoring environment offers more degrees of freedom for authoring component-based applications.  /0 ralf dörner paul grimm
international technology transfer (panel)  for the past two and one half decades, usa suppliers have generally dominated the computer graphics marketplace, providing an estimated 90 percent of computer graphics shipments worldwide. in the past few years, however, a number of non-usa sources have begun to develop products which not only have captured a growing percentage of their domestic markets, but also have begun to be competitive worldwide. usa companies have increasingly turned to non-usa sources for licenses and products. this panel brings together executives from european, asian and south african companies to discuss the growing exchange of computer graphics technology among usa and non-usa suppliers.  carl machover
high-quality pre-integrated volume rendering using hardware-accelerated pixel shading  we introduce a novel texture-based volume rendering approach that achieves the image quality of the best post-shading approaches with far less slices. it is suitable for new flexible consumer graphics hardware and provides high image quality even for low-resolution volume data and non-linear transfer functions with high frequencies, without the performance overhead caused by rendering additional interpolated slices. this is especially useful for volumetric effects in computer games and professional scientific volume visualization, which heavily depend on memory bandwidth and rasterization power.  we present an implementation of the algorithm on current programmable consumer graphics hardware using multi-textures with advanced texture fetch and pixel shading operations. we implemented direct volume rendering, volume shading, arbitrary number of isosurfaces, and mixed mode rendering. the performance does neither depend on the number of isosurfaces nor the definition of the transfer functions, and is therefore suited for interactive high-quality volume graphics.  klaus engel martin kraus thomas ertl
simulation of facility designs on a micro-computer  the design of a high technology production facility quite often hinges on the successful design of a material handling system to integrate the various automation centers. traditionally, management has been reluctant to invest the capital necessary for high technology material handling equipment since they have no guarantee of the performance potential. simulation of a proposed facility design, with a special emphasis on the material handling system is illustrated as a key method for evaluating the proposed design prior to the purchase of production process equipment.  gerald t. mackulak neil glenney
dynamic view-dependent partitioning for structured grids with complex boundaries for object-order rendering techniques  object-order rendering techniques present an attractive approach to run-time visualization of structured grid data, particularly when combined with a parallel rendering paradigm such as image composition. the ability of this combination to exploit hardware exceeds that of parallel image order methods. however, certain configurations of grid boundaries prevent composition from being performed correctly. in particular, when the boundary between two partitions contains concave sections, the partitions may no longer be depth sorted correctly, a requirement for some visualization techniques such as direct volume rendering. this occurs because the concave boundary prevents even the simple ordering of two adjacent partitions. if the data may be repartitioned such that it can be depth sorted correctly, then an image composition approach is a viable option. to facilitate such an operation, we present an algorithm to analyze the geometric structure of a grid boundary and extract knowledge about how the boundary impacts depth sorting and therefore image composition. we then show through examples how this knowledge may be applied to create a set of partitions that may be properly depth sorted.  lance c. burton raghu machiraju donna s. reese
delta: an expert system to troubleshoot diesel electric locomotives  in the last few years, expert systems have become the most visible and fastest growing branch of artificial intelligence. their objective is to capture the knowledge of an expert in a particular problem domain, represent it in a modular, expandable structure, and transfer it to other users in the same problem domain. to accomplish this goal, it is necessary to address issues of knowledge acquisition, knowledge representation, inference mechanisms, control strategies, user interface and dealing with uncertainty.  piero p. bonissone
an analytical comparison of periodic checkpointing and incremental state saving  the successful application of optimistic synchronization techniques in parallel simulation requires that rollback overheads be contained. the chief contributions to rollback overhead in a time warp simulation are the time required to save state information and the time required to restore a previous state. two competing techniques for reducing rollback overhead are periodic checkpointing (lin and lazowska, 1989) and incremental state saving (bauer et al., 1991). this paper analytically compares the relative performance of periodic checkpointing to incremental state savings. the analytical model derived for periodic checkpointing is based almost entirely on the previous model developed by lin (lin and lazowska, 1989). the analytical model for incremental state saving has been developed for this study. the comparison assumes an optimal checkpoint interval and shows under what simulation parameters each technique performs best.  avinash c. palaniswamy philip a. wilsey
a practical model for subsurface light transport  this paper introduces a simple model for subsurface light transport in translucent materials. the model enables efficient simulation of effects that brdf models cannot capture, such as color bleeding within materials and diffusion of light across shadow boundaries. the technique is efficient even for anisotropic, highly scattering media that are expensive to simulate using existing methods. the model combines an exact solution for single scattering with a dipole point source diffusion approximation for multiple scattering. we also have designed a new, rapid image-based measurement technique for determining the optical properties of translucent materials. we validate the model by comparing predicted and measured values and show how the technique can be used to recover the optical properties of a variety of materials, including milk, marble, and skin. finally, we describe sampling techniques that allow the model to be used within a conventional ray tracer.  henrik wann jensen stephen r. marschner marc levoy pat hanrahan
recognition of semantically incorrect rules: a neural-network approach  a novel technique that applies the neural-network learning strategy of back- propagation to recognize semantically incorrect rules is presented. when the rule strengths of most rules are semantically correct, semantically incorrect rules can be recognized if their strengths are weakened or change signs after training with correct samples. in each training cycle, the discrepancies in the belief values of goal hypotheses are propagated backward and the strengths of rules responsible for such discrepancies are modified appropriately. a function called consistent-shift is defined for measuring the shift of a rule strength in the direction consistent with the strength assigned before training and is a critical component of this technique. the viability of this technique has been demonstrated in a practical domain.  li-min fu
kppcdl: an internet based shared environment for introductory programming education the karel++ collaborative laboratory is an internet based educational tool, which facilitates the learning of object-oriented programming techniques, by providing a shared development environment for the building of student programs written in the karel++ language. kppcdl offers remote sharing of karel++ program elements, collaborative source code editing, textual and graphical notification of both coarse and finely grained remote updates, remote and local views of developing program elements, updated views for late comers, background source parsing, and real-time memo sending. the system combines features of both centralized and replicated architectures, and provides for both synchronous and asynchronous collaboration. alfred j. rossi
vertex-based anisotropic texturing  mip mapping is a common method used by graphics hardware to avoid texture aliasing. in many situations, mip mapping over-blurs in one direction to prevent aliasing in another. anisotropic texturing reduces this blurring by allowing differing degrees of filtering in different directions, but is not as common in hardware due to the implementation complexity of current techniques. we present a new algorithm that enables anisotropic texturing on any current mip map graphics hardware supporting mip level biasing, available in opengl 1.2 or through the _gl_ext_texture_lod_bias_ or _gl_sgix_texture_lod_bias_ opengl extensions. the new algorithm computes anisotropic filter footprint parameters per vertex. it constructs the anisotropic filter out of several mip map texturing passes or multi-texture lookups. each lookup uses mip level bias and perturbed texture coordinates to place one probe used to construct the more complex filter profile.  marc olano shrijeet mukherjee angus dorbie
cost of state saving & rollback  approaches to state saving and rollback for a shared memory, optimistically synchronized, simulation executive are presented. an analysis of copy state saving and incremental state saving is made and these two schemes are compared. two benchmark programs are then described, one a simple, all overhead, model and one a performance model of a regional canadian public telephone network. the latter is a large ss7 common channel signalling model that represents a very challenging, practical, test application for parallel simulation. experimental results are presented which show the necessity and sufficiency of incremental state saving for this application.  john cleary fabian gomes brian unger zhonge xiao raimar thudt
documentational analysis: or good common sense  those who never documented their systems are suffering the consequences. in response your friendly marketplace has come up with some solutions to be purchased at the same price as a piece of software. it may or may not be partly software. it is a specific guide for generating documentation in as mechanical and predictable a method possible. if it is mechanical, it can be controlled, and that is what the product is: control. control of system analysis and design. the necessary by-product is documentation.  the kind of analysis that documentation requires, falls under that mysterious grace called "good common sense."  diana patterson
some experiments in object-oriented simulation  discrete event simulation has been a constant source of inspiration for language designers. the present interest in object-oriented programming (o.o.p.) can be traced back to the simula 67 language. in return, simulation languages are currently getting back many advantages from the ongoing research in o.o.p. one of the main present research trends is the possibility of concurrently executing a simulation program composed of a set of interacting and communicating objects. conditions which will make this possible are discussed together with some induced problems. more precisely this paper presents some experiments in object-oriented simulation that reveal the great flexibility of the smalltalk-801 programming system for building evaluation environments.  jean bezivin