ppxscal/embedding_network huggingface dataset:
Abstraction Mechanisms in Support of Top-Down and Bottom-Up Task Specification
Authors: K. S. Raghu, James D. Arthur
Venue:  (1988)

Abstraction is a powerful mechanism for describing objects and relationships from multiple, yet consistent, perspectives. When properly applied to interface design, abstraction mechanisms can provide the interaction flexibility and simplicity so desperately needed and demanded by today''s diverse user community. Fundamental to achieving such goals has been the integration of visual programming techniques with a unique blend of abstraction mechanisms to support user interaction and task specification. The research presented in this paper describes crucial abstraction mechanisms employed within the Taskmaster environment to support top-down and bottom-up task specification. In particular, this paper (a) provides an overview of the Taskmaster environment, (b) describes top-down specification based on multi-level, menu-driven interaction and (c) describes bottom-up specification based on cutset identification and pseudo-tool concepts.
HYBRID ANATOMICALLY BASED MODELING OF ANIMALS
Authors: Philip J. Schneider, Jane Wilhelms
Venue:  (1998)

We describe a new hybrid approach to modeling and animating animals. A pre--defined skin is modeled as a triangle mesh, such as may be purchased from a digital model vendor, or generated with a typical modeling program. This skin is then attached to the underlying bone, muscle, and tissue model. The rest shape of the skin is exactly as given in the surface model of the animal. Internal components -- bones, muscles, and general tissue -- are directly modeled with triangle meshes or ellipsoids. Changes in joint angle result in changes to the position of bones and generalized tissue, and in changes to the shapes of muscles. The attached skin vertices move with their underlying components, resulting in natural-looking deformations to the animal modeled. This alternative approach to modeling skin allows for greater realism or detail without requiring more accurate internals, and it allows pre--existing animal models to be realistically deformed using an anatomically based method.
Specifying an Implementation to Satisfy Interface Specifications: A StateTransition Approach
Authors: Simon S. Lam, A. U Shankar
Venue:  (1988)

We present a solution to the problem posed by Leslie Lamport to participants of the Specification Logics session in the 1987 Lake Arrowhead workshop. Formal specifications are given for a database interface offering serializable access to concurrent client programs, a two-phase locking implementation of the client interface, and the physical-database interface accessed by the implementation. We sketch a proof that the implementation satisfies the client interface specification, assuming that the physical-database interface specification holds.
Convergence/Response Tradeoffs in Concurrent Systems
Authors: Mohamed G. Gouda, Michael Evangelist
Venue:  (1988)

A self-stablizing system is one which if started at any unsafe state, is guaranteed to converge to a safe state within a finite number of state transitions. The convergence span of such a system is defined as the maximum number of critical transitions that can be executed before the system reaches a safe state. In this paper, we discuss the tradeoff between the convergence span of a self-stabilizing system and its response span. In particular, we argue that the convergence span can be reduced by some factor by increasing the response span by the same factor, and vice versa. Our discussion is centered on a class of self-stabilizing systems for detecting termination on a uni-directional ring. The discussion leads to a family of systems whose convergence span is O(n/k), and whose response span is O(nk), where n is the number of processes in the system, and k is a parameter whose value can be chosen arbitrarily from the domain 1...n.
Fast evolutionary algorithms
Authors: Xin Yao, Yong Liu, Ko-Hsin Liang, Guangming Lin
Venue: Advances in evolutionary computing: theory and applications (2003)

This chapter discusses a number of recent results in evolutionary optimization. In particular, we show that the search step size of a variation operator plays a vital role in its efficient search of a landscape. We have derived the optimal search step size of mutation operators in evolutionary optimization. Based on this theoretical analysis, we have developed several new evolutionary algorithms which outperform existing evolutionary algorithms significantly on many benchmark functions.Most of the existing work in evolutionary optimization concentrates on different variation (i.e., search) operators, such as crossover and mutation. However, there may be a better way to solve a complex problem by transforming it into a simpler one first and then solving it. The key issue here is how to approximate the problem without changing the nature of the problem (i.e., the optima we wish to find). This chapter will present the latest results on landscape approximation and hybrid evolutionary algorithms.
Civil Law and the Development of Software Engineering
Authors: Martina Shapiro
Venue:  (1996)

This paper provides software engineers with an understanding of the basic tenets of civil law and how legal liability principles may be applied by the courts so as to affect the future direction of software engineering. The issues discussed are based on a review of selected literature in software engineering, civil law reported case decisions and texts as well as on interviews with legal consultants. Examples of some court rulings in cases involving software malfunction are included, along with some projections relating to the possible implications for software development arising from the anticipated reaction of the courts to the novel issues presented by software engineering. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Semi-Automatic Implementation of Network Protocols
Authors: Daniel A. Ford
Venue:  (1986)

A compiler which achieves automatic implementation of network protocols by transforming specifications written in {\em FDT} into {\em C} programs is presented. A brief introduction to the the fundamentals of {\em FDT}, a standard language developed by ISO/TC97/SC 16/WG 1 Subgroup B for specifying network protocols, is given. We then present an overview of the compiler and discuss the problem of {\em PASCAL} to {\em C} translation. Transformation of a {\em FDT} specification into code is explained and illustrated by two implementation examples. The first example illustrates the implementation strategy by tracing the processing of a simple protocol The second example demonstrates the validity of using automatically generated implementations by showing how a communication path was established between two hosts using code generated for the alternating bit protocol.
Automatic verification of security in payment protocols for electronic commerce
Authors: Maurizio Panti, Luca Spalazzi, Simone Tacconi, Salvatore Valenti
Venue: Enterprise information systems IV (2003)

In order to make secure transactions over computer networks, various cryptographic protocols have been proposed but, because of subtleties involved in their design, many of them have been shown to have flaws, even a long time after their publication. For this reason, several automatic verification methods for analyzing these protocols have been devised. The aim of this paper is to present a methodology for verifying security requirements of electronic payment protocols by means of NuSMV, a symbolic model checker. Our work principally focus on formal representation of security requirements. Indeed, we propose an extension of the correspondence property, so far used only for authentication, to other requirements as confidentiality and integrity. These are the basic security requirements of payment protocols for electronic commerce. We illustrate as case study a variant of the SET protocol proposed by Lu & Smolka. This variant has been formally verified by Ly & Smolka and considered secure. Conversely, we have discovered two attacks that allow a dishonest user to purchase a good debiting the amount to another user.
An Experimental Validation of the ADORA Language
Authors: Stefan Berner, Nancy Schett, Yong Xia, Martin Glinz
Venue:  (2000)

ADORA (Analysis and Description of Requirements and Architecture) is an approach to object oriented modeling that is based on object modeling and hierarchical decomposition, using an integrated model. The ADORA language is intended to be used for requirements specifications and high-level, logical views of software architectures. In order to assess the comprehensibility and the appeal of specifications written in ADORA we conducted a controlled experiment with students. We wrote two specifications of the same problem in ADORA and in UML and let the students study them. Then we tested the students'' comprehension by asking questions about the contents of the specification and tested how they liked ADORA in comparison to UML by asking questions about personal preferences. In this report we describe the experiment and report the results.
AN ANALYSIS OF APPROACHES TO RAY-TRACING CURVILINEAR GRIDS
Authors: Shankar Ramamoorthy, Jane Wilhelms
Venue:  (1992)

Curvilinear grids are composed of six-sided cells which may be considered as resulting from the deformation of a regular rectilinear grid. Unlike regular grids the cells may not be identical in shape, size or orientation. Such grids occur in areas such as computational fluid dynamics (CFD) and finite element methods. Direct volume rendering can be a useful tool for visualizing scalar data on curvilinear grids from CFD. It is possibly more desirable for such smoothly varying fields than isosurface methods that use binary thresholding. Volume rendering research has largely concentrated on rendering scalar fields on regular grids, and recent algorithms allow nearly interactive renderings on moderately sized volumes. These techniques do not readily carry over to rendering curvilinear grids. Curvilinear grids pose a number of challenges to a volume rendering algorithm. In this report, we discuss the problems of ray-casting curvilinear grids and present techniques for speedup at the expense of extra storage. (not available electronically)
Active Messages Implementations for the Meiko CS-2
Authors: Klaus E. Schauser, Chris J. Scheiman
Venue:  (1995)

Active messages provide a low latency communication architecture which on modern parallel machines achieves more than an order of magnitude performance improvement over more traditional communication libraries. It is used by library and compiler writers to obtain the utmost performance and has been used to implement the novel parallel language Split-C. This paper discusses the experience we gained while implementing active messages on the Meiko CS-2, and discusses implementations for similar architectures. The CS-2 is an interesting experimental platform, as it resembles a cluster of Sparc workstations, each equipped with a dedicated communication co-processor. During our work we have identified two mismatches between the requirements of active message and the Meiko CS-2 architecture. First, architectures which only support efficient remote write operations (or DMA transfers as in the case of the CS-2) make it difficult to transfer both data and control as required by active messages. Traditional network interfaces avoid this problem because they have a single point of entry which essentially acts as a queue. To efficiently support active messages on modern network communication co-processors, hardware primitives are required which support this queue behavior. We overcame this problem by producing specialized code which runs on the communications co-processor and supports the active messages protocol. We also identify hardware primitives which are required to efficiently support active messages. The second mismatch is that active messages do not provide a non-blocking form of send, which is required to achieve the highest possible bandwidth while allowing the overlap of communication and computation when a communications co-processor is present. We propose to extend the current active message definition to include a non-blocking form of send. Our implementation of active messages results in a one-way latency of 12.3 us and achieves up to 39 MB/s for bulk transfers. Both numbers are close to optimal for the current Meiko hardware and are competitive with performance of active messages on other hardware platforms.
Browsing intricately interconnected paths
Authors: Pratik Dave, Unmil P. Karadkar, Richard Furuta, Luis Francisco-Revilla, Frank Shipman, Suvendu Dash, Zubin Dalal
Venue: Proceedings of the fourteenth ACM conference on Hypertext and hypermedia (2003)

Graph-centric and node-centric browsing are the two commonly identified hypertext-browsing paradigms. We believe that path-centric browsing, the browsing behavior exhibited by path interfaces, is an independent browsing paradigm that combines useful aspects of the two commonly supported cases. Paths have long been recognized as an effective medium for aggregating and communicating information and have been included in various hypermedia systems as alternate metaphors or supporting tools. The Walden's Paths project promotes path-centric traversal as the primary browsing mechanism over Web-based materials. This paper expands the notion of our paths to include more generalized structures and interconnections across paths. We present an architecture for describing complex networks of such paths. Finally, we discuss the design and present a prototype implementation of the Path Engine, a tool that provides a linear interface for browsing intricately interconnected paths.
Parallel Adaptive GMRES Implementations for Homotopy Methods
Authors: Sosonkina Maria, Allison Donald, Watson Layne T.
Venue:  (1997)

The success of homotopy methods in solving large-scale optimization problems and nonlinear systems of equations depends heavily on the solution of large sparse nonsymmetric linear systems on parallel architectures. Iterative solution techniques, such as GMRES(k), favor parallel implementations. However, their straightforward parallelization usually leads to a poor parallel performance because of global communication incurred by processors. One variation of GMRES(k) considered here is to adapt the restart value k for any given problem and use Householder reflections in the orthogonalization phase to achieve high accuracy and reduce the communication overhead.
To disaggregate or not to disaggregate, that is not the question
Authors: Anand Natrajan, Anh Nguyen-Tuong
Venue:  (1995)

The dichotomy between aggregated and disaggregated states is a false one. It is possible for an aggregated entity to be at many levels of aggregation by storing the relevant data of all levels. In this paper, we propose a scheme, UNIFY, wherein each unit either maintains state information at all allowed levels of aggregation or furnishes it on demand. We present problems with traditional approaches towards aggregation such as temporal inconsistency, chain disaggregation and network flooding. We also deal with issues that we envisage will beset the simulation world such as aggregation of dissimilar entities, dynamic aggregation and the perceiver problem. We describe a framework with which these problems could be solved or tackled better. We study the benefits and disadvantages of UNIFY and propose new directions for research. Finally, we analyze the demands made by our scheme on network, memory and CPU resources.
Characterization of the Solutions Set of Least-Squares Problems by an Extension of Kaczmarz''s Projections Method
Authors: C. Popa
Venue:  (1997)

We give a new characterization of the solutions set of the general (inconsistent) linear least-squares problem using the set of limit-points of an extended version of the classical Kaczmarz''s projections method.We also obtain a `` step error reduction formula'''' which,at least from a theoretical view point,can give us information about the convergence properties of the algorithm.In section 3 we present a modified version of the above extended algorithm,obtained by a class of nonorthogonal transformations of the initial least-squares problem and we prove for it similar results as for the initial one. Some comparisons concerning computational aspects,between our algorithms and others existent in the literature ,are made in the last section of the paper. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Portal technology and architecture: past, present and future
Authors: Christopher Etesse
Venue: Designing portals: opportunities and challenges (2003)

When you arrive on a college campus, you often get an immediate sense of the institution's history and priorities. You may pass a football stadium and residential facilities prior to arriving at the academic core of the university. Frequently referred to as "the quad," this core area physically links the academic buildings, library, administrative offices and student activity center. All campus pathways lead to this physical center of campus. As college campuses have become more electronically connected, the campus Internet portal can easily be seen as a virtual quad. From the campus portal each member of the university community may be linked to all campus services and information, instantly. Each individual's view of the portal can easily be tailored to unique as well as common needs and interests. This online campus portal is an extension of the brick and mortar of the university. As such, it provides not only the feel and look of the university, but also a common communication tool for off-campus and distance learning participants in the college community.One of the primary challenges in learning, especially online learning, is interaction, specifically communication. Most, if not all, higher education learning is geared toward communities of communication. As we've seen in other chapters, portals can provide a cornerstone in creating a sense of community on a campus. This chapter explores the origins of online portals. It outlines the technical history of portals including the first portals, the technology underpinnings of today's portals and the ways in which portals will evolve in the future.Portals can be defined in two ways. One is by the data that reside within the portal and are aggregated for access by the end user of the portal, The second definition is as a framework for accessing, manipulating and interpreting data. This chapter will discuss both definitions. It will also discuss why the portal's data offerings are integral to the balance of these two definitions and how portal framework(s) will become essential in higher education. This chapter will focus on the educational benefits of the past, present and future of portals.
Motion Perturbation Based on Simple Neuromotor Control Models
Authors: Michael B. Cline, KangKang Yin, Dinesh K. Pai
Venue:  (2002)

Motion capture is widely used for character animation. One of the major challenges in this area is modifying human motion in plausible ways. Previous work has focused on transformations based on kinematics and dynamics, but has not explicitly taken into account the emerging knowledge of how humans control their motion. In this paper we show how this can be done using a simple human neuromuscular control model. Our model of muscle forces includes a feedforward term and low gain passive feedback. The feedforward component is calculated from motion capture data using inverse dynamics. The feedback component generates reaction forces to unexpected external disturbances. The perturbed animation is then resynthesized using forward dynamics. This allows us to create animations where the character reacts to unexpected external forces in a natural way (e.g.,when the character is hit by a flying object), but still retains qualities of the original animation. Such technique is useful for applications such as interactive sports video games.
About sensitivity analysis for elastoplastic systems at large strains
Authors: T. Rojc, B. Štok
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

Influence of a discontinuous nature of the elastoplastic systems response at large strain onto their sensitivity with respect to a design parameter is considered in the paper. It is discussed in the framework of the finite element modelling using the direct differentiation method for the sensitivity response calculation. Considering the additive theory of the rate of deformation tensor and a hypoelastic characterization of the elastic response analytical sensitivity expressions are derived. It is shown that sensitivity response cannot be a smooth function on its overall path. This fact is confirmed by some examples where the sensitivities have been calculated by the presented direct differentiation procedure and the corresponding results have been compared to the results obtained by the finite difference method.
Algorithms for the Construction of Invariant Features
Authors: N. Canterakis, Hanns Schulz-Mirbach
Venue:  (1994)

The paper presents algorithms for the construction of features which are invariant with respect to a given transformation group. Two complementary approaches are considered. On the one hand we apply infinitesimal techniques (based on Lie theory) for constructing invariants for the group GL(3,R). This has applications for 3D data sets. On the other hand we examine an alternative to the infinitesimal approach which is based on integral calculus. The basic idea is to calculate appropriate averages over the transformation group for a given function. We show how to extend these techniques to the construction of features for noncompact groups like GL(n,C). The methods are not limited to parametric groups but can be applied to finite groups as well. However, the major advantage is that it is not necessary to solve any differential equations which is a shortcoming of many infinitesimal techniques. Explicit formulas are derived for groups which are especially important in applications. We show how to treat continuous signals in this framework. Finally we apply the presented methods to establish the existence of complete feature sets for arbitrary compact groups. In the second part we present an algorithm which eliminates successively all parameters of the full linear group GL(3,R) acting in the space of bounded functions with compact support, thus yielding a complete set of affine invariant features for arbitrary compact threedimensional intensity images. The algorithm starts by computing the 3-D moments of the image up to the highest desired order and uses the so called infinitesimal method relying on the theory of Lie groups and Lie algebras. For each group parameter to be eliminated we solve a linear partial differential equation and express its solutions in terms of an integral over the image itself. By repeating this process for a special subset of group parameters in a specified order we firstly achieve a reduction of the problem to the orthogonal case. For the elimina