ppxscal/embedding_network huggingface dataset:
Logical Foundations for Programming Semantics
Authors: Paul C. Gilmore, George K. Tsiknis
Venue:  (1990)

This paper was presented to the Sixth Workshop on Mathematical Foundations of Programming Semantics held at Queen''s University, May 15-19,1990. \n\nThe paper provides an introduction to a natural deduction based set theory, NaDSet, and illustrates its use in programming semantics. The need for such a set theory for the development of programming semantics is motivated by contrasting the presentation of recursive definitions within first order logic with their presentation within NaDSet. Within first order logic such definitions are always incomplete in a very simple sense: Induction axioms must be added to the given definitions and extended with every new recursive definition. Within a set theory such as NaDSet, recursive definitions of sets are represented as terms in the theory and are complete in the sense that all properties of the set can be derived from its definition. Such definitions not only have this advantage of completeness, but they also permit recursively defined sets to be members of the universe of discourse of the logic and thereby be shown to be members of other defined sets. \nThe resolution of the paradoxes provided by NaDSet is dependant upon replacing the naive comprehension axiom scheme of an inconsistent first order logic with natural deduction rules for the introduction of abstraction terms into arguments. The abstraction terms admitted are a generalization of the abstraction terms usually admitted into set theory. In order to avoid a confusion of use and mention, the nominalist interpretation of the atomic formulas of the logic forces NaDSet to be second order, although only a single kind of quantifier and variable is required. \nThe use of NaDSet for programming semantics is illustrated for a simple flow diagram language that has been used to illustrate the principles of denotational semantics. The presentation of the semantics within NaDSet is not only fully formal, in contrast to the simply mathematical presentation of denotational semantics, but because NaDSet is formalized as a natural deduction logic, its derivations can be simply checked by machine.
HIERARCHICALLY ACCELERATED RAY CASTING FOR VOLUME RENDERING WITH CONTROLLED ERROR
Authors: Allen VanGelder, Kwansik Kim, Jane Wilhelms
Venue:  (1995)

Ray casting for volume rendering can be accelerated by taking large steps over regions where data need not be processed at a fine resolution. A new implementation is described that utilizes both a user-specified data importance and a high-level data model in appropriate regions to achieve acceleration. Previously reported work exploited high accumulated opacity, transparency, and nearly constant valued regions. This work generalizes homogeneity from nearly constant values to least-squares fits with a set of basis functions. The implemented set supports trilinear functions, and the framework supports other functions. Experience is reported with sequential and small-scale parallel runs. Comparisons are made with other methods on the bases of time, image quality, and sensitivity to error tolerance. Ray casting with zero error provides a reference image with which others are compared quantitatively. The implementation lives within a general system for multi-dimensional trees. For a given error tolerance, this ensures that the same resolution is used in all regions, by all hierarchical rendering methods, whether based on projection or ray-casting. Data-importance functions were found to be a significant source of acceleration. Image comparisons led to identification of the main source of image degradation in projection methods as being color interpolation rather than data interpolation. An improvement to projection methods is suggested, based on hardware texture maps.
Globally Convergent Homotopy Methods for the DC Operating PointProblem
Authors: Robert C. Melville, Ljiljana Trajkovic, San Fang, Layne T. Watson
Venue:  (1990)

Accurate and efficient computer simulation of a proposed design for an integrated circuit ("chip") is essential because of the difficulty and expense of building prototypes for such devices. The transistors and diodes in such circuits are modeled with nonlinear equations, hence simulation of circuits requires the solution of systems of nonlinear equations involving hundreds or even thousands of variables. This paper discusses the application of probability-one homotopy methods to various systems of nonlinear equations which arise in circuit simulation. The so-called "coercivity conditions" which are required for such methods are proved using concepts from circuit theory. The theoretical claims of global convergence for such methods are substantiated by experiments with a collection of examples which have proved difficult for commercial simulation packages which do not use homotopy methods. Moreover, by careful design of the homotopy equations, the performance of the homotopy methods can be made quite reasonable.
Metaphors for the Nature of Human-Computer Interaction in anEmpowering Environment: Interaction Styles Influences the Manner ofHuman Accomplishment
Authors: Herman G. Weller, H. R Hartson
Venue:  (1990)

Over the past four decades, the computer''s role in helping humans solve information problems has increased steadily. New genres of computer applications have arisen, leading to new ways of using computers. Of these, perhaps the most advanced are what we call empowering environments for problem solving with computers. We propose that a closed-loop model of interaction provides a more natural, more accurate description of problem solving with computers. Further we suggest that human accomplishment is strongly enhanced by engagement of the user in such environments, and a key to engagement is the power of an interface as an illusion, representing the real-world problem-solving situation directly to the user. In turn, the illusion is supported by directness, which depends on appropriate and timely feedback closely coupled to the user actions as part of inter-referential input/output.
Design of bolted joints in pressure vessels by dynamic modelling
Authors: M. Ghorashi
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

The dynamic behaviour of a closure bolting system is predicted by the use of a spring-mass-damper model. The loading is assumed to be an initially peaked, exponentially decaying internal pressure pulse acting on the closure. Especial attention is paid to the effect of pre-stress and applied pressure levels on the maximum bolt displacement and stress. The main aim is to find proper values of pre-stress, which comply with the requirements of no closure lift-off and no bolt yielding. The increase of fatigue life is also a major concern and may essentially be accomplished through the reduction of the maximum bolt deformation. It is observed that for some high levels of the applied loading, the maximum bolt deformation, in terms of the implemented pre-load has a minimum for low prestress values. However, it may not be optimal, because the closure lift-off phenomenon is likely to occur at such low pre-stress levels.
Query-Based Debugging
Authors: Raimondas Lencevicius
Venue:  (1999)

Object relationships in modern software systems are becoming increasingly numerous and complex. Program errors due to violations of object relationships are hard to find because of the cause-effect gap between the time when an error occurs and the time when the error becomes apparent to the programmer. Although debugging techniques such as conditional and data breakpoints help to find error causes in simple cases, they fail to effectively bridge the cause-effect gap in many situations. Programmers need new tools that allow them to explore objects in a large system more efficiently and to detect broken object relationships instantaneously. Many existing debuggers present only a low-level, one-object-at-a-time view of objects and their relationships. We propose a new solution to overcome these problems: query-based debugging. The implementation of the query-based debugger described here offers programmers an effective query tool that allows efficient searching of large object spaces and quick verification of complex relationships. Even for programs that have large numbers of objects, the debugger achieves interactive response times for common queries by using a combination of fast searching primitives, query optimization, and incremental result delivery. Dynamic query-based debuggers extend query-based debugging by providing instant error alerts. In other words, they continuously check inter-object relationships while the debugged program is running. To speed up dynamic query evaluation, our debugger (implemented in portable Java) uses a combination of program instrumentation, load-time code generation, query optimization, and incremental reevaluation. Experiments and a query cost model show that selection queries are efficient in most cases, while more costly join queries are practical when query evaluations are infrequent or query domains are small. We thus demonstrate that query-based debugging is a useful method that can be efficiently implemented and effectively used in program debugging.
Identification of Horizontally Acquired DNA Using Genome Signature Analysis
Authors: S. A. Jarvis, J. S. Mirsky, J. F. Peden, N. J. Saunders
Venue:  (2001)

Identification of regions with untypical percentage G+C composition and dinucleotide signatures are two genome analysis techniques used in the identification of horizontally acquired DNA. We describe a generic program framework for performing both types of analysis in linear time. The approach is extended for length <2 oligonucleotide signatures. Using the derived program we test some of the conclusions of Karlin and Burge, the primary exponents of these techniques. We demonstrate that no single method of signature analysis is sufficient for the complete identification of horizontally acquired DNA. Consequently we produce a fast program - and a robust methodology - for the production and employment genome signatures in the identification of horizontally acquired DNA.
Mesh Collapse Compression
Authors: Martin Isenburg, Jack Snoeyink
Venue:  (1999)

Efficiently encoding the topology of triangular meshes has recently been the subject of intense study and many representations have been proposed. The sudden interest in this area is fueled by the emerging demand for transmitting 3D data sets over the Internet (e.g. VRML). Since transmission bandwidth is a scarce resource, compact encodings for 3D models are of great advantage. In this report we present a novel algorithm for encoding the topology of triangular meshes. Our encoding algorithm is based on the edge contract operation, which has been used extensively in the area of mesh simplification, but not for efficient mesh topology compression. We perform a sequence of edge contract and edge divide operations that collapse the entire mesh into a single vertex. With each edge contraction we store a vertex degree and with each edge division we store a start and an end symbol. This uniquely determines all inverse operations. For meshes that are homeomorphic to a sphere, the algorithm is especially simple. Surfaces of higher genus are encoded at the expense of a few extra bits per handle.
Token Systems That Self-stabilize
Authors: Geoffrey M. Brown, Mohamed G. Gouda, Chuan Wu
Venue:  (1988)

We present a new class of mutual exclusion systems, in which processes circulate one token, and each process enters its critical section when it receives the token. Each system in the class is self-stabilizing; i.e. if it starts at any state, possibly one where many tokens exist in the system, it is guaranteed to converge to a good state where exactly one token exists in the system. The systems are better than previous systems in that their state transitions are non-interfering, i.e. if any state transition is enabled at any instant, then it will continue to be enabled until it is executed; this makes the systems easier to implement as delay-insensitive circuits.
Anti-Replay Window Protocols for Secure IP
Authors: Mohamed Gouda, Chin Huang, Eric Li
Venue:  (2000)

The anti-replay window protocol is used to secure IP against an adversary that can insert (possibly replayed) messages in the message stream from a source computer to a destination computer in the Internet. In this paper, we verify the correctness of this important protocol using standard methods (i.e. auxiliary variables, annotation, and invariants). We show that despite the adversary, the protocol delivers each message at most once, and discards a message only if another copy of this message has already been delivered, or the message has suffered a reorder of degree w or more, where w is the window size. We then develop two variations of this protocol: one variation uses two windows of size w/2 each, and the other uses w windows of size one each. We use the same standard methods to show that each of these protocols delivers every message at most once, and discards a message only if another copy of this message has already been delivered, or the message has suffered a reorder of degree w+d or more, where d is the sum of current distances between successive windows in the protocol. These two protocols are shown to be more effective than the original protocol.
Precomplete Negation \& Universal Quantification
Authors: Paul J. Voda
Venue:  (1986)

This paper is concerned with negation in logic programs. We propose to extend negation as failure by a stronger form of negation called precomplete negation. In contrast to negation as failure, precomplete negation has a simple semantic characterization given in terms of computational theories which deliberately abandon the law of the excluded middle (and thus classical negation) in order to attain computational efficiency. The computation with precomplete negation proceeds with the direct computation of negated formulas even in the presence of free variables. Negated formulas are computed in a mode which is dual to the standard positive mode of logic computations. With negation as failure the formulas with tree variables must be delayed until the latter obtain values. Consequently, in situations where delayed formulas are never sufficiently instantiated, precomplete negation can find solutions unattainable with negation as failure. As a consequence of delaying, negation as failure cannot compute unbounded universal quantifiers whereas precomplete negation can. Instead of concentrating on the model-theoretical side of precomplete negation this paper deals with questions of complete computations and efficient implementations.
A Multigrid Method for Shape from Shading
Authors: Uri M. Ascher, Paul M. Carter
Venue:  (1991)

The shape-from-shading problem has received much attention in the Computer Vision literature in recent years. The basic problem is to recover the {\em shape z(x,y)} of a surface from a given map of its {\em shading}, i.e. its variation of brightness over a given domain. Mathematically, one has to solve approximately the {\em image irradiance equation}\\ \begin{center} E(x,y) \end{center} relating a given image irradiance {\em E(x,y)} to the radiance of the surface at each point {\em (x,y)}, with {\em R(p,q)} a given {\em reflectance z_ {x}$ and $q = z_ {y}$. \nA possible presence of noise and lack of adequate boundary conditions adds to the difficulty of this problem. A number of different approaches towards its solution have been proposed in the Vision literature, including various regularization models. However, a reliable, efficient solution method for practical instances has remained elusive so far. \nIn this paper we analyze the various solution models proposed with the aim of applying an efficient multigrid solver. A combination of an FMG-continuation technique with an appropriate discretization of one such solution model proposed by B. Horn yields an efficient solver. Our results are demonstrated by examples.
SimpleScalar Simulation of the PowerPC Instruction Set Architecture
Authors: Karthikeyan Sankaralingam, Ramadass Nagarajan, Stephen W. Keckler, Doug Burger
Venue:  (2001)

In this report, we describe a modification to the SimpleScalar tool set to support the PowerPC ISA. Our work is based on Version 3.0 of the publicly available SimpleScalar tool set. We briefly describe features of the PowerPC ISA relevant to the simulator and provide operating system specific implementation details. We made modifications to the suite of five simulators that model the micro-architecture at different levels of detail. The timing simulator sim-outorder simulates PowerPC binaries on the Register Update Unit (RUU) micro-architecture. The five simulators were tested by simulating the SPEC CPU95 benchmarks to completion. The tool set simulates binaries compiled for 32-bit IBM AIX running on PowerPC.
Fire resistance of protected asymmetric slim floor beams
Authors: W. Sha
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

The effectiveness of the intumescent coatings for fire protecting has been evaluated using fully validated computer models and software, based on fire test data. The project took the following procedure: (i) examination of testing set-up and data, (ii) calculations of moment resistance and load ratio for the coating thickness used, (iii) evaluation of beam temperature distribution as a function of protective coating thickness, (iv) determination of minimum coating thickness required for up to 120 minutes fire resistance, (v) examination of the effect of service holes, (vi) assessment for S607 on asymmetric beams by comparison with test data on SLIMFLOR beams.
The ABCs of designing campus portals
Authors: Ali Jafari
Venue: Designing portals: opportunities and challenges (2003)

This chapter discusses the fundamental design requirements for building Internet portals, in particular building portals for educational institutions or so-called "campus portals." The focus of the chapter is on understanding portals and their design requirements from both functional and technical perspectives for educational applications. It is meant to offer understanding and to share know-how and experience with those who are involved in various aspects of the design, development or implementation of portal projects.
Issues in Object-oriented Database Schemas
Authors: Hyoung Kim
Venue:  (1988)

The successful use of database management systems in data-processing applications has created a substantial amount of interest in applying database techniques to such areas as knowledge bases and artificial intelligence (AI), computer-aided design (CAD), and office information systems (OIS). In order to provide the additional semantics necessary to model these new applications, many researchers have adopted the object-oriented programming paradigm to serve as a data model. In order to use the objectoriented approach in a database system, it was necessary to add persistence and sharability to the object-oriented programming paradigm. Several database systems based on this approach are under implementation. Therefore, object-oriented database systems combine the strengths of object-oriented programming languages and conventional database systems. The practical applications of object-oriented databases, such as CAD, AI, and OIS, require the ability to dynamically make a wide variety of changes to the database schema. This process is called schema evolution. We establish a consistent and complete framework of schema evolution. Based on our framework, the MCC ODBS group implemented a schema manager within their prototype object-oriented database system, ORION. On top of the schema manager of ORION, we implemented a graphical schema editor, PSYCHO.
Cooperative Systems for Perceptual Tasks in a Remote Sensing Environment
Authors: Alan K. Mackworth
Venue:  (1989)

To design and implement knowledge-based systems for perceptual tasks, such as interpreting remotely-sensed data, we must first evaluate the appropriateness of current expert system methodology for these tasks. That evaluation leads to four conclusions which form the basis for the theoretical and practical work described in this paper. The first conclusion is that we should build `cooperative systems'' that advise and cooperate with a human interpreter rather than `expert systems'' that replace her. The second conclusion is that cooperative systems should place the user and the system in symmetrical roles where each can query the other for facts, rules, explanations and interpretations. The third conclusion is that most current expert system technology is {\em ad hoc}. Formal methods based on logic lead to more powerful, and better understood systems that are just as efficient when implemented using modern Prolog technology. The fourth conclusion is that, although the first three conclusions can be, arguably, accepted for high-level rule-based symbol-manipulation tasks, there are difficulties in accepting them for perceptual tasks that rely on visual expertise. In the rest of the paper work on overcoming those difficulties in the remote sensing environment is described. In particular, the issues of representing and reasoning about image formation, map-based constraints, shape descriptions and the semantics of depiction are discussed with references to theories and prototype systems that address them.
ON ALIGNMENT SHIFT AND ITS MEASURES
Authors: Melissa Cline, Kevin Karplus
Venue:  (1998)

This document proposes a new measure for comparing two alignments, referred to as the shift score. This score has a range of -epsilon to 1, where epsilon is a small number used as a parameter to the scoring algorithm. A score of 1 is attained only if the two alignments are identical. The shift score is symmetric with respect to the alignments - no distinguished sequence or alignment is needed. The score incorporates both coverage measures and shift error measures into a single number. The shift score is easily computed, and one can find the optimum subalignment of a candidate alignment (the subalignment that maximizes the shift score) with a simple greedy algorithm.
TRANSIENT ANALYSIS OF COUPLED TRANSMISSION LINES USING SCATTERING PARAMETER BASED MACROMODEL
Authors: Jimmy S Wang, Wayne W Dai
Venue:  (1994)

As the system clock speed increases, crosstalk becomes one of the major sources of noise which can limit the performance of high-speed digital systems in addition to delay and ringing. The congruence transform- ation can be used to decouple a coupled transmission-line system. In this paper, we extended the scattering parameter based macromodel to include the congruence transformation to analyze the crosstalk in the coupled transmission-line systems. After decouple the n coupled transmission lines using the congruence transformation, the computation of scattering matrix of the coupled transmission lines then becomes those of the scattering matrix of the congruence transformers and those of the n decoupled single transmission lines. A very simple scattering parameter description of the congruence transformer for coupled lossless transmission lines is derived. It has been extended to handle the coupled lossy transmission lines. Unlike some of the previous methods [14][16] which only consider the coupling between immediate adjacent lines, our method takes into account the coupling among all lines. We also present the results obtained from our simulator as well as those obtained from the SPICE-like simulators (for example: SPICE3e2 and ASTAP) and state- of-the-art moment-matching simulators (for example: SWEC and Coffee).