waashk/acm huggingface dataset:
homomorphic factorization of brdfs for high-performance rendering  _a bidirectional reflectance distribution function (brdf) describes how a material reflects light from its surface. to use arbitrary brdfs in real-time rendering, a compression technique must be used to represent brdfs using the available texture-mapping and computational capabilities of an accelerated graphics pipeline. we present a numerical technique, homomorphic factorization, that can decompose arbitrary brdfs into products of two or more factors of lower dimensionality, each factor dependent on a different interpolated geometric parameter. compared to an earlier factorization technique based on the singular value decomposition, this new technique generates a factorization with only positive factors (which makes it more suitable for current graphics hardware accelerators), provides control over the smoothness of the result, minimizes relative rather than absolute error, and can deal with scattered, sparse data without a separate resampling and interpolation algorithm._  michael d. mccool jason ang anis ahmad
a simulation approach to design a motoreducer assembly and testing facility  this paper describes the application of a digital computer simulation model to design a large facility for assembling and testing approximately 30,000 motoreducers a year. the simulation model is designed and calibrated entirely on actual operating data, and used in conjunction with statistically designed experiments to evaluate the effects of various controllable factors on the size and configuration of the department level facility. the paper shows that a relatively simple and straightforward simulation model can provide quite insightful and valuable results, yet still be well within the capabilities and budget of the "ordinary practitioner" of management science in facilities planning.  harold j. steudel
multiple-valued complex functions and computer algebra i recently taught a course on complex analysis. that forced me to think more carefully about branches. being interested in computer algebra, it was only natural that i wanted to see how such programs dealt with these problems. i was also inspired by a paper by stoutemyer ([3]).while programs like derive, maple, mathematica and reduce are very powerful, they also have their fair share of problems. in particular, branches are somewhat of an achilles' heel for them. as is well- known, the complex logarithm function is properly defined as a multiple-valued function. and since the general power and exponential functions are defined in terms of the logarithm function, they are also multiple valued. but for actual computations, we need to make them single valued, which we do by choosing a branch. in section 2, we will consider some transformation rules for branches of multiple-valued complex functions in painstaking detail.the purpose of this short article is not to do a comprehensive comparative study of different computer algebra system. (for an attempt at that, see [4].) my goal is simply to make the readers aware of some of the problems, and to encourage the readers to sit down and experiment with their favourite programs.i would like to thank willi-hans steeb and michael wester for helpful comments. helmer aslaksen
gross motion planning - a survey  motion planning is one of the most important areas of robotics research. the complexity of the motion-planning problem has hindered the development of practical algorithms. this paper surveys the work on gross-motion planning, including motion planners for point robots, rigid robots, and manipulators in stationary, time-varying, constrained, and movable-object environments. the general issues in motion planning are explained. recent approaches and their performances are briefly described, and possible future research directions are discussed.  yong k. hwang narendra ahuja
presenting gpss/h results with the graphical kernel system (gks)  this paper discusses the interfacing of the latest version of gpss, namely gpss/h, and gks, a graphics system which allows programs to support a wide variety of graphics devices. a computer program to convert a running gpss/h program to a form compatible for graphical emulation has been developed. an animation program which takes as input the data generated by the modified gpss/h program has also been developed. thus, the gpss programmer needs only to take care of correct modelling of the system under study and need not know anything at all about graphics and animation.  raphael parambi aseem chandawarkar
hardware support for non-photorealistic rendering  special features such as ridges, valleys and silhouettes, of a polygonal scene are usually displayed by explicitly identifying and then rendering `edges' for the corresponding geometry. the candidate edges are identified using the connectivity information, which requires preprocessing of the data. we present a non-obvious but surprisingly simple to implement technique to render such features without connectivity information or preprocessing. at the hardware level, based only on the vertices of a given flat polygon, we introduce new polygons, with appropriate color, shape and orientation, so that they eventually appear as special features.  ramesh raskar
ace: going from prototype to product with an expert system  ace (automated cable expertise) is a knowledge-based expert system that provides trouble-shooting and diagnostic reports for telephone company managers. its application domain is telephone cable maintenance. ace departs from standard expert system architecture in that a separate data base system is used as its primary source of information. ace designers were influenced by the r1/xcon project, and ace uses techniques similar to those of r1/xcon. this paper reports the progress of ace as it moves out of experimentation and into a live software environment, and characterizes it in terms of current expert system technology.  j. r. wright f. d. miller g. v. e. otto e. m. siegfried g. t. vesonder j. e. zielinski
fast line scan-conversion  a major bottleneck in many graphics displays is the time required to scan- convert straight line segments. most manufacturers use hardware based on bresenham's [5] line algorithm. in this paper an algorithm is developed based on the original bresenham scan- conversion together with the symmetry first noted by gardner [18] and a recent double-step technique [31]. this results in a speed-up of scan-conversion by a factor of approximately 4 as compared to the original bresenham algorithm. hardware implementations are simple and efficient since the property of using only shift and increment operations is preserved.  j. g. rokne brian wyvill xiaolin wu
a tutorial on simulation programming with simpas  simpas is a portable, strongly-typed, event-oriented, discrete system simulation language embedded in pascal. it extends pascal by adding statements for event declaration and scheduling, entity declaration, creation and destruction, linked list declaration and manipulation, and statistics collection. a library of standard pseudo-random number generators is also provided. this paper gives a tutorial on simulation programming using simpas. we briefly discuss event- oriented simulation language concepts, give an overview of the programming language pascal, and then describe in detail the simulation extensions that simpas provides.  r. m. bryant
languages for expert system building: a comparison  a study of some languages which may be used for expert system building is conducted. the characteristics necessary in an expert system building language are detailed. languages that are unable to provide for many different types of expert systems to be built are not given much weight. six relatively standard high level languages are studied, which include fortran, modula-2, ada**, pascal, lisp and prolog. some of the newly developed expert system building languages are also studied. the study was done in conjunction with the development of the expert system known as fess and a discussion of the reasons for the choice of its development language are given. the construction of the system has provided further insights for the language study. it is found that a best expert system building language may yet be developed.  ** ada is a trademark of the dod (ada joint program office)  lawrence o. hall abraham kandel
the implementation of temporal intervals in qualitative simulation graphs  in this paper we develop and implement a simulation modeling methodology that combines discrete event simulation with qualitive simulation. our main reason for doing so is to extend the application of discrete event simulation to systems found in business for which precise quantitative information is lacking. the approach discussed in this paper is the implementation of temporal interval specifications in the discrete event model and the construction of a temporal interval clock for the qualitative simulation model.  ricki g. ingalls douglas j. morrice andrew b. whinston
using self-diagnosis to adapt organizational structures  the specific organization used by a multi-agent system is crucial for its effectiveness and efficiency. in dynamic environments, or when the objectives of the system shift, the organization must therefore be able to change as well. in this paper we propose using a general diagnosis engine to drive this process of adaptation, using the \tems\ modeling language as the primary representation of organizational information. results from experiments employing such a system in the producer-consumer-transporter domain are also presented.  bryan horling brett benyo victor lesser
the 21st acm north american computer chess championship  after twenty years of traveling from city to city across the united states, the acm north american computer chess championship came back to the place of its birth, the new york hilton hotel, where the competitions began in 1970. this latest five- round event ended in a two-way tie for first place between mephisto and deep thought/88. finishing in a two-way tie for third place were hitech and m chess. a total of 10 teams participated, and the level of play was at the low grandmaster level. a special three-round end-game championship was won by mephisto, who also captured the prize for the best small computing system. a total of $8000 in prizes was divided up among the winners.  monty newborn danny kopec
a cognitive approach to judicial opinion structure: applying domain expertise to component analysis  empirical research on basic _components_ of american judicial opinions has only scratched the surface. lack of a coordinated pool of legal experts or adequate computational resources are but two reasons responsible for this deficiency. we have undertaken a study to uncover fundamental components of judicial opinions found in american case law. the study was aided by a team of twelve expert attorney-editors with a combined total of 135 years of legal editing experience. the scientific hypothesis underlying the experiment was that after years of working closely with thousands of judicial opinions, expert attorneys would develop a refined and internalized schema of the content and structure of legal cases. in this study participants were permitted to describe both concept-related and format-related components. the resultant components, representing a combination of these two broad categories, are reported on in this paper. additional experiments are currently under way which further validated and refine this set of components and apply them to new search paradigms.  jack g. conrad daniel p. da bney
ray tracing of steiner patches  steiner patches are triangular surface patches for which the cartesian coordinates of points on the patch are defined parametrically by quadratic polynomial functions of two variables. it has recently been shown that it is possible to express a steiner patch in an implicit equation which is a degree four polynomial in x,y,z. furthermore, the parameters of a point known to be on the surface can be computed as rational polynomial functions of x,y,z. these findings lead to a straightforward algorithm for ray tracing steiner patches in which the ray intersection equation is a degree four polynomial in the parameter of the ray. the algorithm presented represents a major simplification over existing techniques for ray tracing free-form surface patches.  thomas w. sederberg david c. anderson
power: using uml/ocl for modeling legislation - an application report  the dutch tax and customs administration (dtca in dutch: belastingdienst) conducts a research program power in which methods and tools are developed that support a systematic translation of (new) legislation into the dtca's processes. the methods and tools developed help to improve the quality of (new) legislation and codify the knowledge used in the translation processes in which legislation and regulations are transformed into procedures, computer programs and other designs. thereby the time-to-market of the implementation of legislation will be reduced. in this article we focus on the method we developed for modeling legislation. we will elaborate upon the principles behind the method and explain the use of catalysis and uml/ocl in the modeling process. the coupling of models of legislation and task models originating from business policy is demonstrated and finally we will show the way knowledge-based components in function of applications are generated automatically.  tom m. van engers rik gerrits margherita boekenoogen erwin glassee patries kordelaar
a tutorial view of simulation model development  working from the background of simulation language developments, we develop an understanding of the current status of simulation model development. factors characterizing the current status include a shift in emphasis from program to model, more commitment to modeling tools, and the lingering impedance of simulation language isolation. current and future needs are identified. specific approaches to meeting these needs are cited in an extensive description of current research, and in summary we conclude that the technology of simulation model development is in a transitional period that portends more rapid changes for the future.  richard e. nance
a generalization of algebraic surface drawing  the mathematical description of three dimensional surfaces usually falls in one of two classifications: parametric and algebraic. the form is defined as all points which satisfy some equation: f(x,y,z) 0. this form is ideally suited for image space shaded picture drawing, the pixel coordinates are substituted for x and y and the equation is solved for z. algorithms for drawing such objects have been developed primarily for first and second order polynomial functions. this paper presents a new algorithm applicable to other functional forms, in particular to the summation of several gaussian density distributions. the algorithm was created to model electron density maps of molecular structures but can be used for other artistically interesting shapes.  james f. blinn
incompleteness in knowledge bases  the first topic for discussion at the high level abstraction workshop was  what should be modelled?  that is, what aspects of the world (slice of reality / enterprise) must be dealt with in a high level conceptual model. i would like to address this question from the point of view of incomplete knowledge bases. although my remarks pertain mainly to ai applications, i suspect that any application using an information system of some sort will eventually have to face similar issues.  the knowledge bases required in many applications can be characterized by a lack of complete information about the world of interest.  hector j. levesque
deep shadow maps  we introduce deep shadow maps, a technique that produces fast, high-quality shadows for primitives such as hair, fur, and smoke. unlike traditional shadow maps, which store a single depth at each pixel, deep shadow maps store a representation of the fractional visibility through a pixel at all possible depths. deep shadow maps have several advantages. first, they are prefiltered, which allows faster shadow lookups and much smaller memory footprints than regular shadow maps of similar quality. second, they support shadows from partially transparent surfaces and volumetric objects such as fog. third, they handle important cases of motion blur at no extra cost. the algorithm is simple to implement and can be added easily to existing renderers as an alternative to ordinary shadow maps.  tom lokovic eric veach
industrial applications of distributed ai  most work done in distributed artificial intelligence (dai) had targeted sensory networks, including air traffic control, urban traffic control, and robotic systems. the main reason is that these applications necessitate distributed interpretation and distributed planning by means of intelligent sensors. planning includes not only the activities to be undertaken, but also the use of material and cognitive resources to accomplish interpretation tasks and planning tasks. these application areas are also characterized by a natural distribution of sensors and receivers in space. in other words, the sensory data- interpretation tasks and action planning are inter-dependent in time and space. for example, in air traffic control, a plan for guiding an aircraft must be coordinated with the plans of other nearby aircraft to avoid collisions.  b. chaib-draa
temporal anti-aliasing in computer generated animation  the desirability of incorporating temporal anti-aliasing, or motion blur, into computer generated animation is discussed and two algorithms for achieving this effect are described. the first approximates continuous object movement and determines intervals during which each object covers each pixel. hidden surface removal is then performed, allowing the calculation of visible object intensity functions and subsequent filtering. the second form of algorithm detailed involves supersampling the moving image and then filtering the resulting intensity function to "multiply-expose" each output picture. the effects of filter types and the relationship of the algorithms to forms of spatial anti-aliasing are discussed.  jonathan korein norman badler
on face detection in the compressed domain  _we propose a fast face detection algorithm that works directly on the compressed dct domain. unlike the previous dct domain processing designs that are mainly based on skin-color detection, our algorithm analyzes both color and texture information contained in the dct parameters, therefore could generate more reliable detection results. our texture analysis is mainly based on statistical model training and detection. a number of fundamental problems,_ e.g., _block quantization, preprocessing in the dct domain, and feature vector selection and classification in the dct domain, are discussed_.  huitao luo alexandros eleftheriadis
understanding supercritical speedup  simulations running under time warp using lazy cancellation can beat the bound given by the critical path. we explain this phenomenon to be the result of a kind of intra-object parallelism. specifically, we show that instances of beating the critical path, called supercritical speedup, are made possible by messages that are independent of some event which precedes the message. this insight leads to a new definition for the critical path which is a tighter lower bound on time-warp simulations using lazy cancellation than any previously proposed. these results suggest criteria for choosing between lazy and aggressive cancellation.  michial a. gunter
a two-list method for synchronization of event driven simulation  the traditional mechanism for maintaining a list of pending events in a discrete event simulation is the simple linked list. however, in large scale simulations this list often becomes cumbersome to maintain since the number of pending events may become quite large. as a result, the execution time required by the simple linked list is often a significant portion of total simulation time. several articles have been published suggesting improved synchronization procedures. the most efficient procedures reported are the time indexed procedure and the two level procedure. both methodologies are designed for use in languages such as pascal or pl/l, and as a result neither algorithm translates well into fortran. further, both procedures require external parameter definition, which is a major handicap to their adoption by a general purpose language. this paper introduces a new synchronization procedure, the two list procedure, which is much faster than simple linked lists for large pending event files. this procedure was designed for implementation in fortran, and properly implemented it is transparent to the user; thus it is ideal for adoption by general purpose simulation languages.  john h. blackstone gary l. hogg don t. phillips
a sketch of logic without truth  1\\. jøgensen's dilemma - 2. the proposed solution - 3. short history of a philosophical prejudice - 4. the abstract, syntactical and semantic notion of consequence - 4.1. the abstract notion of consequence - 4.2. the syntactical notion of consequence - 4.3. the semantic notion of consequence - 4.4. the meaning given by rules of use in a context - 4.5. which operators does logic require? - 5. deontic logic - 6. the consequences for computer scientists.  c. e. alchourrón a. a. martino
contour tracing by piecewise linear approximations  we present a method for tracing a curve that is represented as the contour of a function in euclidean space of any dimension. the method proceeds locally by following the intersections of the contour with the facets of a triangulation of space. the algorithm does not fail in the presence of high curvature of the contour; it accumulates essentially no round-off error and has a well-defined integer test for detecting a loop. in developing the algorithm, we explore the nature of a particular class of triangulations of euclidean space, namely, those generated by reflections.  david p. dobkin allan r. wilks silvio v. f. levy william p. thurston
an experimental evaluation of computer graphics imagery  accurate simulation of light propagation within an environment and perceptually based imaging techniques are necessary for the creation of realistic images. a physical experiment that verifies the simulation of reflected light intensities for diffuse environments was conducted. measurements of radiant energy flux densities are compared with predictions using the radiosity method for those physical environments. by using color science procedures the results of the light model simulation are then transformed to produce a color television image. the final image compares favorably with the original physical model. the experiment indicates that, when the physical model and the simulation were viewed through a view camera, subjects could not distinguish between them. the results and comparison of both test procedures are presented within this paper.  gary w. meyer holly e. rushmeier michael f. cohen donald p. greenberg kenneth e. torrance
improving the representation of legal case texts with information extraction methods  the prohibitive cost of assigning indices to textual cases is a major obstacle for the practical use of ai and law systems supporting reasoning and arguing with cases. while progress has been made toward extracting certain facts from well-structured case texts or classifying case abstracts under key number concepts, these methods still do not suffice for the complexity of indexing concepts in cbr systems.  in this paper, we lay out how a better example representation may facilitate classification-based indexing. our hypotheses are that (1) abstracting from the individual actors and events in cases, (2) capturing actions in multi-word features, and (3) recognizing negation, can lead to a better representation of legal case texts for automatic indexing. we discuss how to implement these techniques with state-of-the-art nlp tools. preliminary experimental results suggest that a combination of domain-specific knowledge and information extraction techniques can be used to generalize from the examples and derive more powerful features.  stefanie bruninghaus kevin d. ashley