waashk/acm huggingface dataset:
further experience with controller-based automatic motion synthesis for articulated figures  we extend an earlier automatic motion-synthesis algorithm for physically realistic articulated figures in several ways. first, we summarize several incremental improvements to the original algorithm that improve its efficiency significantly and provide the user with some ability to influence what motions are generated. these techniques can be used by an animator to achieve a desired movement style, or they can be used to guarantee variety in the motions synthesized over several runs of the algorithm. second, we report on new mechanisms that support the concatenation of existing, automatically generated motion controllers to produce complex, composite movement. finally, we describe initial work on generalizing the techniques from 2d to 3d articulated figures. taken together, these results illustrate the promise and challenges afforded by the controller-based approach to automatic motion synthesis for computer animation.  joel auslander alex fukunaga hadi partovi jon christensen lloyd hsu peter reiss andrew shuman joe marks j. thomas ngo
a generative model of narrative cases  effective case-based reasoning in complex domains requires a representation that strikes a balance between expressiveness and tractability. for cases in temporal domains, formalization of event transitions in a narrative grammar can simplify both the user's task of problem formulation and the system's indexing, matching, and adaptation tasks without compromising expressiveness. this paper sets forth a model of temporal cases based on narrative grammars, demonstrates its applicability to several different domains, distinguishes two different similarity metrics---sequence overlap and tree overlap---and shows how the choice between these metrics depends on whether nonterminals in the narrative grammar correspond to abstract domain states or merely represent constraints on event transitions. the paper shows basic-level and legal-event narrative grammars can be used together to model how human lawyers interleave fact elicitation and analysis.  l. karl branting
control strategies for two-player games  computer games have been around for almost as long as computers. most of these games, however, have been designed in a rather ad hoc manner because many of their basic components have never been adequately defined. in this paper some deficiencies in the standard model of computer games, the minimax model, are pointed out and the issues that a general theory must address are outlined. most of the discussion is done in the context of control strategies, or sets of criteria for move selection. a survey of control strategies brings together results from two fields: implementations of real games and theoretical predictions derived on simplified game-trees. the interplay between these results suggests a series of open problems that have arisen during the course of both analytic experimentation and practical experience as the basis for a formal theory.  bruce abramson
relief texture mapping  we present an extension to texture mapping that supports the representation of 3-d surface details and view motion parallax. the results are correct for viewpoints that are static or moving, far away or nearby. our approach is very simple: a relief texture (texture extended with an orthogonal displacement per texel) is mapped onto a polygon using a two-step process: first, it is converted into an ordinary texture using a surprisingly simple 1-d forward transform. the resulting texture is then mapped onto the polygon using standard texture mapping. the 1-d warping functions work in texture coordinates to handle the parallax and visibility changes that result from the 3-d shape of the displacement surface. the subsequent texture-mapping operation handles the transformation from texture to screen coordinates.  manuel m. oliveira gary bishop david mcallister
simulating pass transistor circuits using logic simulation machines  an algorithm for pass transistor simulation using the yorktown simulation engine (yse) is outlined. implementing this algorithm yields an efficient tool for custom vlsi circuit design verification and fault simulation.  modeling of circuits under this environment is defined, including the analysis of the algorithm's performance for some general circuit types. a number of specific examples are discussed in detail.  z. barzilai l. huisman g. silberman d. tang l. woo
an updated survey of ga-based multiobjective optimization techniques  after using evolutionary techniques for single-objective optimization during more than two decades, the incorporation of more than one objective in the fitness function has finally become a popular area of research. as a consequence, many new evolutionary-based approaches and variations of existing techniques have recently been published in the technical literature. the purpose of this paper is to summarize and organize the information on these current approaches, emphasizing the importance of analyzing the operations research techniques in which most of them are based, in an attempt to motivate researchers to look into these mathematical programming approaches for new ways of exploiting the search capabilities of evolutionary algorithms. furthermore, a summary of the main algorithms behind these approaches is provided, together with a brief criticism that includes their advantages and disadvantages, degree of applicability, and some known applications. finally, further trends in this area and some possible paths for further research are also addressed.  carlos a. coello
modeling of computer systems (panel session)  over ten years have elapsed since the first symposium on the simulation of computer systems in 1973\. for several years thereafter there were similar conferences held. sessions at numerous winter simulation conferences have features papers on simulation of computer systems. yet more and more attention has been paid to analytical models for determination of projected performance of computer systems. is this the result of proven accuracy, ease of use, cost- effectiveness or lack of knowledge of simulation? in what instances is it necessary or desirable to use simulation rather than analytical models?  paul f. roth
merging text and graphics  the capability to merge graphics and text into a consolidated document can greatly enhance communication. even simple graphics such as boxes and arrows can help organize ideas and make information easier to understand. it is still disturbing to see the number of manuals that describe computer graphics systems that do not include even one graphic image!  in the phototypesetting world, the capability to merge graphics and text has been available for some time, but only recently have the components for less costly systems become available. this paper will discuss a segmented system in use in a scientific r&amp;d; environment for including graphics into documents.  judi cleary
lod-sprite technique for accelerated terrain rendering  we present a new rendering technique, termed lod-sprite rendering, which uses a combination of a level-of-detail (lod) representation of the scene together with reusing image sprites (previously rendered images). our primary application is accelerating terrain rendering. the lod-sprite technique renders an initial frame using a high- resolution model of the scene geometry. it renders subsequent frames with a much lower-resolution model of the scene geometry and texture-maps each polygon with the image sprite from the initial high-resolution frame. as it renders these subsequent frames the technique measures the error associated with the divergence of the view position from the position where the initial frame was rendered. once this error exceeds a user-defined threshold, the technique re-renders the scene from the high- resolution model. we have efficiently implemented the lod-sprite technique with texture-mapping graphics hardware. although to date we have only applied lod-sprite to terrain rendering, it could easily be extended to other applications. we feel lod- sprite holds particular promise for real-time rendering systems.  baoquan chen j. edward swan eddy kuo arie kaufman
geometric modeling technology  the geometric model is an essential element of the design description. it is an abstract representation of the form and size of the object that serves as a medium of communication. the geometric model must hold sufficient information to answer all questions about form and size. the traditional engineering drawing was developed for and has served this function. though highly developed, over a long period, the technique suffers from the fact that much of the information is implied and many times is ambiguous. it takes a trained human to interpret a drawing, a computer can't. various approaches have been taken in design modeling and the capabilities and limitation should be understood before approaches are selected or rejected. the wire frame, surface and volumes approaches can form a complimentary system of modeling capabilities rather than replace each other. the need for multiple representation appears when deeper consideration is given to specific applications.  william luts
a hypercube ray-tracer  we describe a hypercube ray-tracing program for rendering computer graphics. for small models, which fit in the memory of a single processor, the ray- tracer uses a scattered decomposition of pixels to balance the load, and achieves a very high efficiency. the more interesting case of large models, which cannot be stored in a single processor, requires a decomposition of the model data as well as the pixels. we present algorithms for constructing a decomposition based upon information about the frequency with which different elements of the model are accessed. the resulting decomposition is approximately optimized to minimize communication and achieve load balance.  j. salmon j. goldsmith
observations on comparing digital systems synthesis techniques  previously, much research effort has been aimed at developing automatic design methods for the higher levels of system design. this work has centered around developing methods of representation, constraint specification, and automatic design. specifically, methods of representing systems at the behavioral and functional block levels were developed and implemented. around these representations, automatic design methods have been developed. this paper describes the previous research efforts, highlights their results, and makes observations on the comparison of these design methods.  donald e. thomas
igks (abstract only): an integrated image processing and graphics environment  this paper describes a part of a large project at the university of lowell to develop an integrated environment for the unified treatment of image processing and graphics with interfaces to pictorial databases. the overall systems consists of a knowledge-based user interface containing three orthogonal kernels:  an image processing and vision kernel system (iks) and  the graphical kernel system (gks)  several pictorial databases  one can think of a kernel as a set of procedures, tools and utilities that are coherent, orthogonal and fundamental. in our environment, all kernels are closely linked. there is a very strong link between the image/vision kernel and the graphics one. this is specifically referred to as the image and graphics kernel system (igks) and this is the focus of this paper. this system is interfaced to the user through a knowledge-base and rule-based system (referred to symbolically as ).  george grinstein
using motives and artificial emotions for long-term activity of an autonomous robot  to operate over a long period of time in the real world, autonomous mobile robots must have the capability of recharging themselves whenever necessary. in addition to be able to find and dock into a charging station, robots must be able to decide when and for how long to recharge. this decision is influenced by the energetic capacity of their batteries and the contingencies of their environments. to deal with this temporality issue and using research evidences from the field of psychology, this study investigates the use of motives and artificial emotions to regulate the recharging need of autonomous robots.  françois michaud jonathan audet
a collaborative legal information retrieval system using dynamic logic programming  we propose a framework for a collaborative legal information retrieval system based on dynamic logic programming. in order to be collaborative our system keeps the context of the interaction and tries to infer the user intentions. each event is represented by logic programming facts which are used to dynamically update the previous user model. user intentions are inferred from this new model and are the basis of the interaction between the system and the legal texts knowledge base. as legal texts knowledge base we are using the documents from the portuguese attorney general (procuradoria geral da republica). in this paper we will show some examples of the obtained collaborative behaviour.  paulo quaresma irene pimenta rodrigues
application of enriched deontic legal relations: federal rules of civil procedure rule 7(a), pleadings  deontic legal relations are quantified obligation or permission statements in the logic of legal relations. such legal relations stem from hohfeld's right- duty-privilege-no-right set of fundamental legal conceptions. the four hohfeldian roots are enriched by more detailed specification in terms of quantifier, deontic, action and temporal logics. the 1600 enriched deontic legal relations defined in the logic of legal relations are both more specific and more discriminating than their hohfeldian predecessors. a brief summary is presented of the 800 active enriched deontic legal relations along with other parts of the legal relations language involved in the analysis of the important rule 7(a) of the federal rules of civic procedure dealing with pleadings.  layman e. allen charles s. saxon
a simple computational model for nonmonotonic and adversarial legal reasoning  in many commonsense contexts only incoherent and conflicting information is available. in such contexts reasonable conclusions must be derived from inconsistent sets of premises. this is especially the case in legal reasoning: legal norms can be issued by different authorities, in different times, to reach incompatible socio-political objectives, and the meaning of those norms can be semantically indeterminate.  logic deduction alone is insufficient to derive justified conclusions out of inconsistent legal premises, since in the most popular logical systems (such as classical or intuitionistic logic) everything can be deduced from any contradiction. nevertheless, much research now underway shows that formal methods can be developed for reasoning with conflicting information. the possibility of obtaining justified conclusions from an inconsistent set of premises increases when an ordering is defined over that set, since the ordering of the premises can be translated into an ordering of the competing arguments. this fact is particularly relevant for legal reasoning, since lawyers effectively solve normative conflicts by using ordering relations.  in the following page, a model for reasoning with ordered defaults, interpreted as unidirectional inference rules, is proposed: a language for representing (possibly) contradictory rules is introduced, a notion of argument is defined, and types of arguments are distinguished. a simple interpreter in prolog able to develop those arguments is also illustrated. finally, the significance of the proposed model (and, more generally, of the acceptance of inconsistency) for the formal analysis of legal systems is discussed.  giovanni sartor
optical printing in computer animation  the optical printer can be considered as an optical analog computer, which can perform geometric transformations and simple arithmetic operations on pictures very efficiently. the principles of operation of the printer are explained, and many of its applications to computer animation are listed and discussed briefly.  two techniques are discussed in detail: the use of high contrast masks to suppress the bright spots where two lines of different colors cross, and the use of continuous tone masks and multiple exposures to create realistic transparency at low cost.  nelson max john blunden
the pessimism behind optimistic simulation  in this paper we make an analogy between the time that storage must be maintained in an optimistic simulation and the blocking time in a conservative simulation. by exploring this analogy, we design two new global virtual time (gvt) protocols for time warp systems. the first protocol is based on null message clock advancement in conservative approaches. our main contribution is a new protocol inspired by misra's circulating marker scheme for deadlock recovery. it is simple enough to be implemented in hardware, takes no overhead in the normal path, can be made to work over non-fifo links, and its overhead can be dynamically tuned based on computational load.  george varghese roger chamberlain william e. weihl
a 3-dimensional representation for fast rendering of complex scenes  hierarchical representations of 3-dimensional objects are both time and space efficient. they typically consist of trees whose branches represent bounding volumes and whose terminal nodes represent primitive object elements (usually polygons). this paper describes a method whereby the object space is represented entirely by a hierarchical data structure consisting of bounding volumes, with no other form of representation. this homogencity allows the visible surface rendering to be performed simply and efficiently.  the bounding volumes selected for this algorithm are parallelepipeds oriented to minimize their size. with this representation, any surface can be rendered since in the limit the bounding volumes make up a point representation of the object. the advantage is that the visibility calculations consist only of a search through the data structure to determine the correspondence between terminal level bounding volumes and the current pixel. for ray tracing algorithms, this means that a simplified operation will produce the point of intersection of each ray with the bounding volumes.  memory requirements are minimized by expanding or fetching the lower levels of the hierarchy only when required. because the viewing process has a single operation and primitive type, the software or hardware chosen to implement the search can be highly optimized for very fast execution.  steven m. rubin turner whitted
super-criticality revisited  critical path analysis has been suggested as a technique for establishing a lower bound on the completion times of parallel discrete event simulations. a protocol is super-critical if there is at least one simulation that can complete in less than the critical path time using that protocol. previous studies have shown that several practical protocols are super-critical while others are not. we present a sufficient condition to demonstrate that a protocol is super-criticality. it has been claimed that super-criticality requires independence of one or more messages (states) on events in the logical past of those messages (states). we present an example which contradicts this claim and examine the implications of this contradiction on lower bounds.  sudhir srinivasan paul f. reynolds
the purdue university network-computing hubs: running unmodified simulation tools via the www  this paper describes the web interface management infrastructure of a functioning network-computing system (punch) that allows users to run unmodified simulation packages at geographically dispersed sites. the system currently contains more than fifty university and commercial simulation tools, and has been used to carry out more than two hundred thousand simulations via the world wide web. dynamically-constructed virtual urls allow the web interface management infrastructure to support the semantics associated with an interface to computing services without requiring any changes to web browsers or www protocols. virtual urls also facilitate customizable control of access to networked resources. simulation tools with text-based interfaces are supported via dynamically-generated, virtual interfaces, whereas tools with graphical interfaces are supported by leveraging available remote display-management technologies. virtual interface generation and interactivity emulation are handled by a programmable state machine in conjunction with a mechanism to embed variables and ovjects within standard html.  nirav h. kapadia jose a. b. fortes mark s. lundstrom
recent developments in expert systems  the most important development in expert systems is the introduction and proliferation of frameworks, or shells, that allow rapid prototyping, easy expansion, and continued maintenance. several shells are now in commercial use and have been used to build expert systems of recognized value. the state of the art and several new lines of development will be discussed. some of the developments involve fundamental research in ai on knowledge representation and inference; others involve making the shell environments themselves more intelligent.  b buchanan
bounds and error estimates for radiosity  we present a method for determining a posteriori bounds and estimates for local and total errors in radiosity solutions. the ability to obtain bounds and estimates for the total error is crucial fro reliably judging the acceptability of a solution. realistic estimates of the local error improve the efficiency of adaptive radiosity algorithms, such as hierarchical radiosity, by indicating where adaptive refinement is necessary.  first, we describe a hierarchical radiosity algorithm that computes conservative lower and upper bounds on the exact radiosity function, as well as on the approximate solution. these bounds account for the propagation of errors due to interreflections, and provide a conservative upper bound on the error. we also describe a non-conservative version of the same algorithm that is capable of computing tighter bounds, from which more realistic error estimates can be obtained. finally, we derive an expression for the effect of a particular interaction on the total error. this yields a new error-driven refinement strategy for hierarchical radiosity, which is shown to be superior to brightness-weighted refinement.  dani lischinski brian smits donald p. greenberg
filtering high quality text for display on raster scan devices  recently several investigators have studied the problem of displaying text characters on grey level raster scan displays. despite arguments suggesting that grey level displays are equivalent to very high resolution bitmaps, the performance of grey level displays has been disappointing. this paper will show that much of the problem can be traced to inappropriate antialiasing procedures. instead of the classical (sin x)/x filter, the situation calls for a filter with characteristics matched both to the nature of display on crts and to the human visual system. we give examples to illustrate the problems of the existing methods and the advantages of the new methods. although the techniques are described in terms of text, the results have application to the general antialiasing problem---at least in theory if not in practice.  j. kajiya m. ullner