waashk/acm huggingface dataset:
parallel lumigraph reconstruction  this paper presents three techniques for reconstructing lumigraphs/lightfields on commercial ccnuma parallel distributed shared memory computers. the first method is a parallel extension of the software-based method proposed in the lightfield paper. this expands the ray/two-plane intersection test along the film plane, which effectively becomes scan conversion. the second method extends this idea by using a shear/warp factorization that accelerates rendering. the third technique runs on an sgi reality monster using up to eight graphics pipes and texture mapping hardware to reconstruct images. we characterize the memory access patterns exhibited using the hardware-based method and use this information to reconstruct images from a tiled uv plane. we describe a method to use quad-cubic reconstruction kernels. we analyze the memory access patterns that occur when viewing lumigraphs. this allows us to ascertain the cost/benefit ratio of various tilings of the texture plane.  peter-pike sloan charles hansen
near real-time shaded display of rigid objects  described is a visible surface algorithm and an implementation that generates shaded display of objects with hundreds of polygons rapidly enough for interactive use --- several images per second. the basic algorithm, introduced in [fuchs, kedem and naylor, 1980], is designed to handle rigid objects and scenes by preprocessing the object data base to minimize visibility computation cost. the speed of the algorithm is further enhanced by its simplicity, which allows it to be implemented within the internal graphics processor of a general purpose raster system.  henry fuchs gregory d. abram eric d. grant
future dependent events, as shown by the example of slam  random events in discrete simulation models are classified in ordinary and future dependent events. an event occurring between to and t is classified as an ordinary event, if the probability distribution for the realization in time is known at time to. if changes of the system after time to can affect the probability distribution of an event, it is called a future dependent event. to show the difference we give two examples.  in contrary to ordinary events future dependent events are not well supported by the currently most used languages like gpss, simula, simscript and slam. in taking slam as an example, we are going to demonstrate, how to adapt a simulation language to be able to handle future dependent events with as slight an effort as possible.  heimo h. adelsberger
real-time programmable shading  one of the main techniques used by software renderers to produce stunningly realistic images is programmable shading---executing an arbitrarily complex program to compute the color at each pixel. thus far, programmable shading has only been available on software rendering systems that run on general-purpose computers. rendering each image can take from minutes to hours.  parallel rendering engines, on the other hand, have steadily increased in generality and in performance. we believe that they are nearing the point where they will be able to perform moderately complex shading at real-time rates. some of the obstacles to this are imposed by hardware, such as limited amounts of frame-buffer memory and the enormous computational resources that are needed to shade in real time. other obstacles are imposed by software. for example, users generally are not granted access to the hardware at the level required for programmable shading.  this paper first explores the capabilities that are needed to perform programmable shading in real times. we then describe the design issues and algorithms for a prototype shading architecture on pixelflow, an experimental graphics engine under construction. we demonstrate through examples and simulation that pixelflow will be able to perform high- quality programmable shading at real-time (30 to 60 hz) rates. we hope that our experience will be useful to shading implementors on other hardware graphics systems.  anselmo lastra steven molnar marc olano yulan wang
an experimental comparison of rgb, yiq, lab, hsv, and opponent color models  the increasing availability of affordable color raster graphics displays has made it important to develop a better understanding of how color can be used effectively in an interactive environment. most contemporary graphics displays offer a choice of some 16 million colors; the user's problem is to find the right color.  folklore has it that the rgb color space arising naturally from color display hardware is user-hostile and that other color models such as the hsv scheme are preferable. until now there has been virtually no experimental evidence addressing this point.  we describe a color matching experiment in which subjects used one of two tablet- based input techniques, interfaced through one of five color models, to interactively match target colors displayed on a crt.  the data collected show small but significant differences between models in the ability of subjects to match the five target colors used in this experiment. subjects using the rgb color model matched quickly but inaccurately compared with those using the other models. the largest speed difference occurred during the early convergence phase of matching. users of the hsv color model were the slowest in this experiment, both during the convergence phase and in total time to match, but were relatively accurate. there was less variation in performance during the second refinement phase of a match than during the convergence phase.  two-dimensional use of the tablet resulted in faster but less accurate performance than did strictly one- dimensional usage.  significant learning occurred for users of the opponent, yiq, lab, and hsv color models, and not for users of the rgb color model.  michael w. schwarz william b. cowan john c. beatty
spatial input/display correspondence in a stereoscopic computer graphic work station  an interactive stereoscopic computer graphic workspace is described. a conventional frame store is used for three-dimensional display, with left/right eye views interlaced in video and viewed through plzt shutter glasses. the video monitor is seen reflected from a half silvered mirror which projects the graphics into a workspace, into which one can reach and manipulate the image directly with a "magic wand". the wand uses a magnetic six degree-of-freedom digitizer. in an alternative configuration, a graphics tablet was placed within the workspace for input intensive tasks.  christopher schmandt
vicious strategies for vickrey auctions  we show that the vickrey auction, despite its theoretical benefits, is inappropriate if "antisocial" agents participate in the auction process. more specifically, an antisocial attitude for economic agents that makes {\em reducing the profit of competitors}\/ their main goal besides maximizing their own profit is introduced. under this novel condition, agents need to deviate from the dominant truth-telling strategy. this paper presents a strategy for bidders in repeated vickrey auctions who are intending to inflict losses to fellow agents in order to be more successful, not in absolute measures, but relatively to the group of bidders.  felix brandt gerhard wei
hardware accelerated rendering of csg and transparency  this paper describes algorithms for implementing accurate rendering of csg and transparency in a hardware 3d accelerator. the algorithms are based on a hardware architecture which performs front-to-back z-sorted shading; a multiple-pass algorithm which allows an unlimited number of z-sorted object layers is also described. the multiple-pass algorithm has been combined with an image partitioning algorithm to improve efficiency, and to improve performance of the resulting hardware implementation.  michael kelley kirk gould brent pease stephanie winner alex yen
applications of the dempster-shafer theory of evidence for simulation  the dempster-shafer theory of belief functions shows promise as a means of incorporating incompleteness of evidence into simulation models. the key feature of the dempster-shafer theory is that precision in inputs is required only to a degree justified by available evidence. the output belief function contains an explicit measure of the firmness of output probabilities. this paper gives an overview of belief function theory, presents the basic methodology for application to simulation, and gives a simple example of a simulation involving belief functions.  kathryn b. laskey marvin s. cohen
simultaneous presentation in text generation (abstract only)  the early part of the 1980s has seen increasing interest and research in computer generation of text which has lead to the creation of several systems to handle various aspects of the text generation process. some of these systems include mckeown's text system [6], appelt's kamp [1], mcdonald's mumble [5] and mann's penman system [3] (which includes matthiessen's nigel [4]).  as proposed by thompson [7], the text generation process can profitably be viewed as consisting of a strategic component which decides what to say and a tactical component which determines how to say it. in terms of processing, the strategic component uses the speaker's intentions, real-world knowledge, and knowledge of the user's beliefs and knowledge to produce a message structure containing the message elements to be presented and the relation between these message elements. the tactical component takes the message structure and produces the final text so as to convey both the propositional content as well as the speaker's attitude and intentions.  in the various text generation systems that have been produced the message elements in the message structure are processed serially. that is, one element is realized, then the next, etc. there are, however, situations where one message element appears to "interrupt" another. when this occurs the impression is that the two message elements are presented in parallel. i call this situation simultaneous presentation. simultaneous presentation is realized in text by parenthetical phrases, appositives, and unrestricted relative clauses.  there are three uses for simultaneous presentation: correction of perceived ambiguous or unsuccessful reference, definition of terms and naming of concepts, and emphasis on the co-reference of two items. preliminary results indicate that the three uses may be distinguished by the identification intention proposed by appelt for concept activation actions [2]. these three uses have in common the fact that each involves the co- reference of the two elements presented simultaneously. indeed, it appears that simultaneous presentation is an explicit indication of co- reference.  my research demonstrates that simultaneous presentation is a useful and necessary capability if a text generation system is to have full expressive power. the conditions under which simultaneous presentation can and cannot be used felicitously will be considered as well as the effects of the use of simultaneous presentation on the final text produced. in addition, the implications of simultaneous presentation for the text generation process and the requirements it places on a text generation system will also be studied. the final result will be to produce a system capable of using simultaneous presentation. i believe it should be possible to produce such a system by building on currently existing strategic and tactical text generators (mckeown's text system and mcdonald's mumble are one possibility). such a system should have particular utility in the generation of explanations and will be tested in such a domain.  kenneth r. lee
trends in high performance graphic systems(panel session)  accompanying the rapid development of integrated circuit fabrication technology has been a parallel, but slower, development of ic design techniques and systems. recent approaches to ic design enable individual designers to consider developing their own vlsi circuits. such capability may open the door to a more varied set of system designs than could previously be considered in most design environments.  the panel members are all currently designing graphic systems oriented towards vlsi implementation. each will give a short presentation describing one of their system designs. following these presentations, three members of the previous session (forest baskett, andreas bechtolsheim, and fred parke) will discuss common issues, problems, and future prospects.  henry fuchs d. cohen bob sproull jim clark fred parke
enhancing information retrieval by automatic acquisition of textual relations using genetic programming  we have explored a novel method to find textual relations in electronic documents using genetic programming and semantic networks. this can be used for enhancing information retrieval and simplifying user interfaces. the automatic extraction of relations from text enables easier updating of electronic dictionaries and may reduce interface area both for search input and hit output on small screens such as cell phones and pdas (personal digital assistants).  agneta bergström patricija jaksetic peter nordin
achieving scalability and expressiveness in an internet-scale event notification service  this paper describes the design of siena, an internet-scale event notification middleware service for distributed event-based applications deployed over wide-area networks. siena is responsible for selecting the notifications that are of interest to clients (as expressed in client subscriptions) and then delivering those notifications to the clients via access points. the key design challenge for siena is maximizing expressiveness in the selection mechanism without sacrificing scalability of the delivery mechanism. this paper focuses on those aspects of the design of siena that fundamentally impact scalability and expressiveness. in particular, we describe siena's data model for notifications, the covering relations that formally define the semantics of the data model, the distributed architectures we have studied for siena's implementation, and the processing strategies we developed to exploit the covering relations for optimizing the routing of notifications.  antonio carzaniga david s. rosenblum alexander l. wolf
three approaches to heuristic search in networks  three different approaches to heuristic search in networks are analyzed. in the first approach, as formulated initially by hart, nilsson, and raphael, and later modified by martelli, the basic idea is to choose for expansion that node for which the evaluation function has a minimum value. a second approach has recently been suggested by nilsson. in this method, in contrast to the earlier one, a node that is expanded once is not expanded again; instead, a "propagation" of values takes place. the third approach is an adaptation for networks of an and/or graph "marking" algorithm, originally due to martelli and montanari.  five algorithms are presented. algorithms a and c illustrate the first approach; propa and propc, the second one; and marka, the third one. the performances of these algorithms are compared for both admissible and inadmissible heuristics using the following two criteria: (i) cost of the solution found; (ii) time of execution in the worst case, as measured by the number of node expansions (a, c), or node "selections" (propa, propc), or arc "markings" (marka).  the relative merits and demerits of the algorithms are summarized and indications are given regarding which algorithm to use in different situations.  a. bagchi a. mahanti
dialectic semantics for argumentation frameworks  we provide a formalism for the study of dialogues, where a dialogue is a two- person game, initiated by the proponent who defends a proposed thesis. we examine several different winning criteria and several different dialogue types, where a dialogue type is determined by a set of positions, an attack relation between positions and a legal-move function. we examine two proof theories, where a proof theory is determined by a dialogue type and a winning criterion. for each of the proof theories we supply a corresponding declarative semantics.  h. jakobovits d. vermeir
monological reason-based logic: a low level integration of rule-based reasoning and case-based reasoning  this paper contains an informal introduction to a theory about legal reasoning (reason-based logic) that takes the notion of a reason to be central. arguing for a conclusion comes down to first collecting the reasons that plead for and against the conclusion, and second weighing them. the paper describes how we can establish the presence of a reason and how we can argue whether the reasons for or the reasons against the conclusion prevail. it also addresses the topic of meta-level reasoning about the use of rules in concrete cases. it is shown how both rule-based reasoning and case-based reasoning are naturally incorporated in the theory of reason-based logic.  jaap hage
a system for monte carlo experimentation  a new computer system for monte carlo experimentation is presented in this thesis. the new system speeds and simplifies the process of coding and preparing a monte carlo experiment; it also encourages the proper design of monte carlo experiments, and the careful analysis of the experimental results.  a new functional language is the core of this system. monte carlo experiments, and their experimental designs, are programmed in this new language; those programs are compiled into fortran output. the fortran output is then compiled and executed. the experimental results are analyzed with a standard statistics package such as s, isp, or minitab or with a user supplied program. both the experimental results and the experimental design may be directly loaded into the workspace of those packages.  the new functional language frees programmers from many of the details of programming an experiment. experimental designs such as factorial, fractional factorial or latin square are easily described by the control structures and expressions of the language. specific mathematical models, such as arima(p,n,q) models, regression models with specific collinearity properties, tabular data generated by logit or log-linear models are generated by the routines of the language. numerous random number generators and many standard statistic routines are included. it is easy to use standard variance reduction techniques, such as common or antithetic variables, conditional monte carlo, weighted samples, importance sampling or control variates.  david alan grier
vizcraft (case study): a multimensional visualization tool for aircraft configuration design  we describe a visualization tool to aid aircraft designers during the conceptual design stage. the conceptual design for an aircraft is defined by a vector of 10-30 parameters. the goal is to find a vector that minimizes an objective function while meeting a series of constraints. vizcraft integrates the simulation code that evaluates the design with visualizations for analyzing the design individually or in contrast to other designs. vizcraft allows the designer to easily switch between the view of a design in the form of a parameter set, and a visualization of the corresponding aircraft. the user can easily see which, if any, constraints are violated. vizcraft also allows the user to view a database of designs using parallel coordinates.  a. goel c. baker c. a. shaffer b. grossman r. t. haftka w. h. mason l. t. watson
learning to use a text processing system: evidence from "thinking aloud" protocols  there is growing interest in cognitive science in the the mental processes that underly learning and using computer systems (e. g., bott {1}; mayer, {2}; card, moran & newell {3}). in this paper we report generalizations about the problems people who are not experienced with computers have learning to use a text-processing system. we are especially interested in unaided self- instruction, because of the practical interest in reducing the role of experienced personel in the training process. we analyze these difficulties in terms of the interaction between the cognitive characteristics of the learner, and the design of self-instruction, and the interface. finally, we are also interested in implications of these problems for designing better training methods and computer interfaces that are easier to learn.  clayton lewis robert mack
conception of cognitive interfaces for legal knowledge: evolution of the jurisque project on the risks of avalanches  this work falls within the field of model-based legal information retrieval. we were brought to conceive new types of interfaces after having evaluated a legal database available on the internet. although legally validated, this legal database jurisque-1 was considered as unsuitable to the expertise's necessities of mountains' professionals (whether legal practitioners or not) working on practical issues of responsibility in cases of avalanches. we thus proposed to develop _cognitive interfaces_ which have the peculiarity to integrate a _model_ of the field into the management of various resources (software packages or knowledge) and ensure that they communicate with one another.  filipe borges danièle bourcier evelyne andreewsky raoul borges
austlll's aide - natural language legislative rulebases  aide (`austlii inferencing development environment') provides a quasi-natural language form of knowledge representation which is reasonably close to statutory language, but at the same time represents knowledge so that it can be used by an inferencing engine using predicate calculus.  aide also provides a supportive development environment for the user by parse tree differentiation to assist the user choosing the correct parsing of rules. the development environment and the user environment are both web-based, facilitating collaborative development of knowledgebases, and the integration of inferencing dialogues with legal source texts on the web.  russell allen philip chuns andrew mowbray graham greenleaf
gi-cube: an architecture for volumetric global illumination and rendering  the power and utility of volume rendering is increased by global illumination. we present a hardware architecture, gi-cube, designed to accelerate volume rendering, empower volumetric global illumination, and enable a host of ray- based volumetric processing. the algorithm reorders ray processing based on a partitioning of the volume. a cache enables efficient processing of coherent rays within a hardware pipeline. we study the flexibility and performance of this new architecture using both high and low level simulations.  frank dachille arie kaufman
on the power of the frame buffer  raster graphics displays are almost always refreshed out of a frame buffer in which a digital representation of the currently visible image is kept. the availability of the frame buffer as a two-dimensional memory array representing the displayable area in a screen coordinate system has motivated the development of algorithms that take advantage of this memory for more than just picture storage. the classic example of such an algorithm is the depth buffer algorithm for determining visible surfaces of a three-dimensional scene. this paper constitutes a first attempt at a disciplined analysis of the power of a frame buffer seen as a computational engine for use in graphics algorithms. we show the inherent power of frame buffers to perform a number of graphics algorithms in terms of the number of data fields (registers) required per pixel, the types of operations allowed on these registers, and the input data. in addition to upper bounds given by these algorithms, we prove lower bounds for most of them and show most of these algorithms to be optimal.  one result of this study is the introduction of new frame buffer algorithms for computing realistic shadows and for determining the convex intersection of half spaces, an operation important in computational geometry and in rendering objects defined using planes rather than polygons. another result is that it shows clearly the relationships between different and important areas of research in computer graphics, such as visible surface determination, compositing, and hardware for smart frame buffers.  alain fournier donald fussell