ppxscal/embedding_network huggingface dataset:
Constraint-Based Agents: A Formal Model for Agent Design
Authors: Alan K. Mackworth, Ying Zhang
Venue:  (2001)

Formal models for agent design are important for both practical and theoretical reasons. The Constraint-Based Agent (CBA) model includes a set of tools and methods for specifying, designing, simulating, building, verifying, optimizing, learning and debugging controllers for agents embedded in an active environment. The agent and the environment are modelled symmetrically as, possibly hybrid, dynamical systems in Constraint Nets. This paper is an integrated presentation of the development and application of the CBA framework, emphasizing the important special case where the agent is an online constraint-satisfying device. Using formal modeling and specification, it is often possible to verify complex agents as obeying real-time temporal constraint specifications and, sometimes, to synthesize controllers automatically. In this paper, we take an engineering point of view, using requirements specification and system verification as measurement tools for intelligent systems. Since most intelligent systems are real-time dynamic systems, the requirements specification must be able to represent timed properties. We have developed timed $\forall$-automata for this purpose. We present this formal specification, examples of specifying requirements and a general procedure for verification. The CBA model demonstrates the power of viewing constraint programming as the creation of online constraint-solvers for dynamic constraints.
UIMS: Toward the Next Generation
Authors: H. R Hartson, Deborah Hix
Venue:  (1986)

First generation User Interface Management Systems (UIMS) have established themselves in both research and commercial areas. This paper discusses improved usability and extension of UIMS to include a broader whole system development life cycle as the basis for evolution of a second generation of UIMS. Problems of first generation UIMS, some informal empirical work that is leading toward an interface development life cycle and UIMS to directions for the anticipated evolution are presented.
Rapid Prototyping in Human-Computer Interface Development
Authors: H. R Hartson, Eric C. Smith
Venue:  (1989)

Some conventional approaches to interactive system development tend to force commitment to design detail without a means for visualizing the result until it is too late to make significant changes. Rapid prototyping and interactive system refinement, especially for the human interface, allow early observation of system behavior and opportunities for refinement in response to user feedback. The role of rapid prototyping for evaluation of interface designs is set in the system development life cycle. Advantages and pitfalls are weighed, and detailed examples are used to show the application of rapid prototyping in a real development project. Kinds of prototypes are classified according to how they can be used in the development process, and system development issues are presented. The future of rapid prototyping depends on solutions to technical problems that presently limit effectiveness of the techniques in the context of present day software development environments.
Content-Description Interfaces for Medical Imaging
Authors: Chee U Ng, Graham R. Martin
Venue:  (2001)

This technical report presents an introduction to content-based information retrieval (CBIR) in the domain of medical imaging. CBIR is a very actively researched area in recent years, however, utilising it in the healthcare community is still relatively new and unexplored. This report provides a survey of current CBIR research, with special emphasis on medical imaging. Research has also been done in the MPEG-7 area, especially on the Contour Shape Descriptor. An implementation and experimental results of the Contour Shape Descriptor using Curvature Scale Space (CSS) are also discussed.
Efficient Routing in All-Optical Networks
Authors: P. Raghavan, E. Upfal
Venue:  (1995)

Communication in all-optical networks requires novel routing paradigms. The high bandwidth of the optic fiber is utilized through wavelength-division multiplexing : A single physical optical link can carry several logical signals, provided that they are transmitted on different wavelengths. We study the problem of routing a set of requests (each of which is a pair of nodes to be connected by a path) on sparse networks using a limited number of wavelengths, ensuring that different paths using the same wavelength never use the same physical link.
Systematic vs. Local Search for SAT
Authors: Holger H. Hoos, Thomas Stuetzle
Venue:  (1999)

Due to its prominence in artificial intelligence and theoretical computer science, the propositional satisfiability problem (SAT) has received considerable attention in the past. Traditionally, this problem was attacked with systematic search algorithms, but more recently, local search methods were shown to be very effective for solving large and hard SAT instances. Especially in the light of recent, significant improvements in both approaches, it is not very well understood which type of algorithm performs best on a specific type of SAT instances. In this article, we present the results of a comprehensive empirical study, comparing the performance of some of the best known stochastic local search and systematic search algorithms for SAT on a wide range of problem instances, including Random-3-SAT and SAT-encoded problems from different domains. We show that while for Random-3-SAT local search is clearly superior, more structured instances are often, but not always, more efficiently solved by systematic search algorithms. This suggests that considering the specific strengths and weaknesses of both approaches, hybrid algorithms or portfolio combinations might be most effective for solving SAT problems in practice.
Optimal Time Bounds for Approximate Clustering
Authors: Ramgopal R. Mettu, C. G Plaxton
Venue:  (2001)

We give randomized constant-factor approximation algorithms for the k-median problem and an intimately related clustering problem. The input to each of these problems is a metric space with n weighted points and an integer k, 0 > k > = n. For any such input, let R>sub<d>/sub< denote the ratio between the maximum and minimum nonzero interpoint distances, and let R>sub<w>/sub< denote the ratio between the maximum and minimum nonzero point weights. We analyze the running time of our algorithms in terms of the parameters n, k, R>sub<d>/sub< and R>sub<w>/sub<. We prove that over a wide range of parameter settings, the complexity of both problems is Theta(nk).
Why Is a Goto Like a Dynamic Vector in the BCPL-Slim Computing System
Authors: Harvey Abramson
Venue:  (1980)

The Slim computer is a new virtual machine which can be used in the translation and porting of the BCPL compiler, and eventually, in the porting of an operating system written in BCPL. For the purposes of this paper, the Slim computer is a stack machine with a single accumulator and a register which points to the top of the stack. The procedures LEVEL and LONGJUMP, traditionally used to implement transfers of control across BCPL procedures, and which are usually written in the assembler language of a host machine, cannot be used with this architecture. In developing procedures to implement \underline{all} transfers of control, we show how these essential procedures --- though highly dependant on the slim architecture --- can be written portably in BCPL, and discover an interesting connection between implementing jumps and dynamic vectors (by means of Aptovec) in the BCPL-Slim computing system. Some parameters of portability in rapping an abstract machine to host machines are identified, and it is shown how to maintain the portability of the above mentioned procedures in the face of various mapping problems. Finally, we are led to a comment on the design of BCPL to the effect that \underline{goto}''s are an unnecessary feature of the language.
TOPOLOGICAL CONSIDERATIONS IN ISOSURFACE GENERATION
Authors: Allen VanGelder, Jane Wilhelms
Venue:  (1994)

A popular technique for rendition of isosurfaces in sampled data is to consider cells with sample points as corners and approximate the isosurface in each cell by one or more polygons whose vertices are obtained by interpolation of the sample data. That is, each polygon vertex is a point on a cell edge, between two adjacent sample points, where the function is estimated to equal the desired threshold value. The two sample points have values on opposite sides of the threshold, and the interpolated point is called an intersection point. When one cell face has an intersection point in each of its four edges, then the correct connection among intersection points becomes ambiguous. An incorrect connection can lead to erroneous topology in the rendered surface, and possible discontinuities. We show that disambiguation methods, to be at all accurate, need to consider sample values in the neighborhood outside the cell. This paper studies the problems of disambiguation, reports on some solutions, and presents some statistics on the occurrence of such ambiguities. A natural way to incorporate neighborhood information is through the use of calculated gradients at cell corners. They provide insight into the behavior of a function in well-understood ways. We introduce two gradient-consistency heuristics that use calculated gradients at the corners of ambiguous faces, as well as the function values at those corners, to disambiguate at a reasonable computational cost. These methods give the correct topology on several examples that caused problems for other methods we examined. (Supersedes UCSC-CRL-90-14)
Segmentation and Classification of Domestic Moving Objects using a Syntactic Approach
Authors: Sok G Lim, Mike Alder, Christopher J.S. deSilva
Venue:  (1994)

In this paper, we propose a method for segmenting and classifying domestic moving objects using a syntactic approach. The problem is to recognise moving objects in front of the camera in a domestic environment such as human beings, curtains blown by the wind and external events such as tree branches, and the aim is to distinguish moving human heads from moving curtains or tree branches. In real-world images, the situation where a human being is moving in the foreground and at the same time the curtains and/or tree branches are moving in the background, often arises. We use quadratic neurons (represented by quadratic forms) as our simple pattern primitives and extract the structural information based on the relationships between the forms. We call this the UpWrite process, and it can be applied any number of times. To achieve our aim of recognising moving heads, we require two levels of the UpWrite process. We hypothesise that the syntactic UpWrite is implemented in wetware by distinct layers of neurons.
A Probabilistic Duration Calculus
Authors: Zhiming Liu, Anders P. Ravn, Erlin V. Sorensen, Chaochen Zhou
Venue:  (1992)

This paper presents a calculus that enables a designer of an embedded, real-time system to reason about and calculate whether a given requirement will hold with a sufficient high probability for given failure probabilities for components used in the design of the system. The main idea is to specify requirements and design in Duration Calculus, a real-time, interval logic, to define satisfaction probabilities for formulas in this calculus, and establish a calculus with rules that support calculation of the probability for a composite formula from probabilities of its constituents. This ensures that reasoning about probabilities is consistent with requirements and design decisions. We thus avoid introducing separate models for requirements and reliability analysis. The system model is a finite automaton with fixed transition probabilities. This defines discrete Markov processes as basis for the calulus. Keywords: duration calculus, real-time systems, probabilistic automata, satisfaction probability.
An Intensity-Based Method for the 3-D Motion and Structure Estimation fromBinocular Image Sequences
Authors: An Luo, Hans Burkhardt
Venue:  (1994)

This paper presents a new intensity-based stereo algorithm using cooperative bidirectional matching with a hierarchical multilevel structure. Based on a new model of piecewise smooth depth fields and the consistency constraint, the algorithm is able to estimate the 3-D structure and detect its discontinuities and the occlusion reliably with low computational costs. In order to find the global optimal estimates, we utilize a multiresolution two-stage algorithm minimizing nonconvex cost functions, which is equivalent to the MAP estimation. This basic framework computing the 3-D structure from binocular stereo images has been extended to the trinocular stereo vision for a further improvement of the performance. A few examples for the binocular and trinocular stereo problems are given to illustrate the performance of the new algorithms.
Virtual Symmetry Reduction
Authors: E. A Emerson, John W. Havlicek, Richard J. Trefler
Venue:  (2000)

We provide a general method for ameliorating state explosion via symmetry reduction in certain asymmetric systems, such as systems with many similar, but not identical, processes. The method applies to systems whose structures (i.e., state transition graphs) have more state symmetries than arc symmetries. We introduce a new notion of "virtual symmetry" that strictly subsumes earlier notions of "rough symmetry" and "near symmetry" [ET99]. Virtual symmetry is the most general condition under which the structure of a system is naturally bisimilar to its quotient by a group of state symmetries. We give several example systems exhibiting virtual symmetry that are not amenable to symmetry reduction by earlier techniques: a one-lane bridge system, where the direction with priority for crossing changes dynamically; an abstract system with asymmetric communication network; and a system with asymmetric resource sharing motivated from the drinking philosophers problem. These examples show that virtual symmetry reduction applies to a significantly broader class of asymmetric systems than could be handled before.
Application of the Analytic Hierarchy Process to Complex System Design Evaluation
Authors: Michael L. Talbert, Osman Balci, Richard E. Nance
Venue:  (1994)

This paper examines the use of the Analytic Hierarchy Process (AHP) to weight indicators used in the evaluation of complex systems designs which involve software, hardware, and humanware. Since such a comprehensive easily include hundreds of system quality indicators, evaluators need a technique to ensure the identification and emphasis of salient indicators in the determination of the quality of the design. The AHP is a popular technique for determining relative worth among a set of elements. In the present work, we introduce AHP with a simple example, then illustrate the application of the AHP to design evaluation using a subset of indicators from the human component of a system. We note in some detail issues which require added attention when applying AHP to this domain. The issues include indicator selection, dealing with large numbers of indicators, incorporating group judgements, and conflict resolution. We found AHP to be an effective tool for use in assigning weights criticality in indicator-based design evaluation, and propose elements of an environment in which the use of AHP is easily incorporated.
A Query Language for Information Graphs
Authors: Sangita C. Betrabet, Edward A. Fox, Qi Chen
Venue:  (1993)

In this paper we propose a database model and query language for information retrieval systems. The information graph model and Graph Object Access Language (GOAL) allow integrated handling of data, information and knowledge along with a variety of specialized objects (e.g., for geographic or multimedia information systems). There is flexible support for hyperbases, thesauri, lexicons, and both relational and object-oriented types of DBMS applications. In this paper we give the first published account of our new, powerful model and language (GOAL), illustrate their use, and compare them with related work.
The Sounds of Physical Shapes
Authors: Kees van den Doel, Dinesh K. Pai
Venue:  (1996)

We propose a general framework for the simulation of sounds produced by colliding physical objects in a real time graphics environment. The framework is based on the vibration dynamics of bodies. The computed sounds depend on the material of the body, its shape, and the location of the impact. Specifically, we show how to compute (1) the spectral signature of each body (its natural frequencies), which depends on the material and the shape, (2) the ``timbre'''' of the vibration (the relative amplitudes of the spectral components) generated by an impulsive force applied to the object at a grid of locations, (3) the decay rates of the various frequency components which correlates with the type of material, based on the its internal friction parameter and finally (4) the mapping of sounds on to the object''s geometry for real time rendering of the resulting sound. The framework has been implemented in a Sonic Explorer program, which simulates a room with several objects such as a chair, tables, and rods. After a preprocessing stage, the user can hit the objects at different points to interactively produce realistic sounds.
The Edge-isoperimetric Number of Generalized Cylinders
Authors: M. C Azizoglu, Omer Egecioglu
Venue:  (1999)

A $d$--dimensional generalized cylinder $G^d$ is the Cartesian product of $d$ graphs, each of which is a path graph or a cycle graph. We use an embedding technique to show that the edge--isoperimetric number $i(G^d)$ is given by $$i(G^d) = \min \{ i (P_k), i (C_l) \}$$ where $P_k$ and $C_l$ are the largest path graph and the largest cycle graph among the factors in $G^d$, and the factor on the right achieving the minimum value has an even number of vertices. As a byproduct, we obtain the isoperimetric number of multidimensional even tori (product of cycle graphs on even number of vertices) and multidimensional even arrays (product of path graphs on even number of vertices). In fact for tori and arrays, our result only requires the size of the largest factor to be even. We also obtain a complete description of the corresponding isoperimetric sets as well as exact formulas for the bisection width of these generalized cylinders.
Decision Graph Search
Authors: Runping Qi, David Poole
Venue:  (1993)

A decision graph is an AND/OR graph with a certain evaluation function. Decision graphs have been found a very useful representation for a variety of decision making problems. This article present a number of search algorithms computing an optimal solution from a given decision graph. These algorithms include one {\it depth-first heuristic-search algorithm}, one {\it best-first heuristic-search algorithm}, one {\it anytime-algorithm} and two {\it iterative-deepening depth-first heuristic-search algorithms}. Similar to the *-minimax search algorithms of Ballard, our depth-first heuristic-search algorithm is developed from the alpha--beta algorithm for minimax tree search. In addition, we show how heuristic knowledge can be used to improve search efficiency. Furthermore, we present an anytime algorithm which is conveniently obtained from the depth-first heuristic-search algorithm without incurring much overhead. The best-first heuristic-search algorithm is obtained by modifying the well known AO* algorithm for AND/OR graphs with additive costs. The iterative-deepening algorithms result from combining the iterative-deepening techniques with the depth-first search techniques. Some experimental data on some of these algorithms performance are given.
Multiresolution Gaussian Mixture Models: Theory and Application
Authors: Roland Wilson
Venue:  (2000)

This paper introduces a new generalisation of scale-space and multiresolution pyramids, which combines statistical modelling with a spatial representation. The representation uses the familiar concept of multiple resolutions, but applied to a Gaussian mixture representation of the image; hence the title Multiresolution Gaussian Mixture Model (MGMM). It is shown that MGMM can approximate any probability density and can deal with the smooth motions that typically occur in image analysis and vision. An efficient recursive algorithm for computing MGMM representations, based on Monte Carlo Markov Chain methods, is presented. After a brief presentation of the theory, examples are used to show how MGMM can be applied to vision problems such as segmentation, stereopsis and motion analysis.
Mathematical models of uncertainty with a regard to membrane systems
Authors: Adam Obtułowicz
Venue: Natural Computing: an international journal (2003)

A brief review is presented of the known mathematical models of uncertainty taking into account its grounds such as randomness, indiscernibility, and vagueness. Then, one discusses the models of the uncertainty caused by indiscernibility and random indiscernibility with a regard to membrane systems. The discussed models include rough sets, probabilistic rough sets, and probabilistic fuzzy sets. An algebraic characterization of P systems is presented, which makes possible to ``transfer'' the methods of Petri net theory to P system theory including the approach of the first theory to models of uncertainty.
TSpec: A Specification of Memory Access Traces
Authors: Sally A. McKee, D. A. B. Weikle, Wm Wulf
Venue:  (1997)

This document describes Tspec, a "little language" for specifying memory traces, and Tint, an interpreter for Tspec. Tspec can be used to generate synthetic traces, or can be used to represent an actual trace in a human-readable, compressed format. We do not address here how to convert a trace into a Tspec specification.
Resampled Curvature and Torsion Scale Space Representation of Planar and Space Curves
Authors: Farzin Mokhtarian
Venue:  (1988)

The curvature scale space representations of planar curves are computed by combining information about the curvature of those curves at multiple levels of detail. Similarly, curvature and torsion scale space representations of space curves are computed by combining information about the curvature and torsion of those curves at varying levels of detail. \nCurvature and torsion scale space representations satisfy a number of criteria such as efficiency, invariance, detail, sensitivity, robustness and uniqueness [Mokhtarian \& Mackworth 1986] which makes them suitable for recognizing a noisy curve at any scale or orientation. \nThe renormalized curvature and torsion scale space representations [Mackworth \& Mokhtarian 1988] are more suitable for recognition of curves with non-uniform noise added to them but can only be computed for closed curves. \nThe resampled curvature and torsion scale space representations introduced in this paper are shown to be more suitable than the renormalized curvature and torsion scale space representations for recognition of curves with non-uniform noise added to them. Furthermore, these representations can also be computed for open curves. \n A number of properties of the representation are also investigated and described. An important new property presented in this paper is that no new curvature zero-crossing points can be created in the resampled curvature scale space representation of simple planar curves.