ppxscal/embedding_network huggingface dataset:
Specification \& Initialization of a Logic Computer System
Authors: Anthony J. Kusalik
Venue:  (1985)

A logic computer system consists of an inference machine and a compatable logic operating system. This paper describes prospective models for a logic computer system, and its hardware and software components. The language Concurrent Prolog serves as the single implementation specification, and machine language. The computer system is represented as a logic programming goal {\em logic\_computer\_system}. Specification of the system corresponds to resolution of this goal. Clauses used to solve the goal --- and ensuing subgoals --- progressively refine the machine, operating system, and computer system designs. In addition, the accumulation of all clauses describing the logic operating system constitute its implementation. Logic computer systems with vastly different fundamental characteristics can be concisely specified in this manner. Two contrasting examples are given and discussed. An important characteristic of both peripheral devices and the overall computer system, whether they are restartable or perpetual, is examined. As well, a method for operational initialization of the logic computer system is presented. The same clauses which incrementally specify characteristics of the computer system also describe the manner in which this initialization takes place.
Design, Implementation, and Analysis of a Split-C Profiler
Authors: Bjoern Haake
Venue:  (1996)

Because parallel programs are very complex, their execution is hard to understand. A tool that supports the analysis of a parallel program is called a profiler. In this thesis, we compared different profiling techniques and examined existing profiling tools. We used these informations to design and implement a profiler for Split-C. Split-C is a parallel extension to C. Most of the existing implementations are based on active messages, a fast communication mechanism. Split-C provides a global address space, where every processor has access to. Split-phase assignments help to overlap computation with communication. We use a version of Split-C that is implemented on the Meiko CS-2 parallel machine. The Meiko is built from SuperSparc processors that are interconnected via a fat-tree network. This resembles a network of Sparc 10 workstations. The Split-C profiler measures the different communication routines and creates entries for a tracefile in the PICL format. The overhead introduced by the PICL calls varies, in most of the routines it ranges from 1--10 \%, only some of the routines imposed a larger overhead between 20 and 40 percent. Roundtrip communication adds larger overhead. The overhead is greater in Split-C compared to MPI (Message Passing Interface, the original target for PICL) because Split-C communication routines are approximately 10 times faster than MPI''s. The tracefile can be postprocessed via a graphical interface, such as ParaGraph. We used ParaGraph because it has a very convenient display and uses colors for a helpful and understandable output. We achieved to use the Split-C profiler for improving some large applications.
Building a campus portal: a strategy that succeeded
Authors: Anne Yandell Bishop
Venue: Designing portals: opportunities and challenges (2003)

In 1997 Wake Forest University began the project of building a suite of personalized Web services that is now known as a portal. By July of 1998, we had a fully implemented and successful intranet that delivered almost one hundred personalized, filtered Web services to all students, faculty and staff, plus those alumni and parents who applied for a free account. Being on the leading edge of such an effort meant that we discovered on our own what works and what does not, without influence from portal vendors or benefit of advice from our peers at other institutions. This paper discusses successful design and implementation strategies that may be useful to others who are considering a portal solution.
Informative Labeling Schemes for Graphs
Authors: D. Peleg
Venue:  (2000)

This paper introduces the notion of informative labeling schemes for arbitrary graphs. Let f(W) be a function on subsets of vertices W. An f labeling scheme labels the vertices of a weighted graph G in such a way that f(W) can be inferred (or at least approximated) efficiently for any vertex subset W of G by merely inspecting the labels of the vertices of W, without having to use any additional information sources. A number of results illustrating this notion are presented in the paper. We begin by developing f labeling schemes for three functions f over the class of n-vertex trees. The first function, SepLevel, gives the separation level of any two vertices in the tree, namely, the depth of their least common ancestor. The second, LCA, provides the least common ancestor of any two vertices. The third, Center, yields the center of any three given vertices v>sub<1>/sub<,v>sub<2>/sub<,v>sub<3>/sub< in the tree, namely, the unique vertex z connected to them by three edge-disjoint paths. All of these three labeling schemes use O(log2 n)-bit labels, which is shown to be asymptotically optimal. Our main results concern the function Steiner(W), defined for weighted graphs. For any vertex subset W in the weighted graph G, Steiner(W) represents the weight of the Steiner tree spanning vertices of W in G. Considering the class of n-vertex trees with M-bit edge weights, it is shown that for this class there exists a Steiner labeling scheme using O((M+logn)logn) bit labels, which is asymptotically optimal. It is then shown that for the class of arbitrary n-vertex graphs with M-bit edge weights, there exists an approximate-Steiner labeling scheme, providing an estimate (up to a factor of O(O{logn})) for the Steiner weight Steiner(W) of a given set of vertices W, using O((M+logn)log2 n) bit labels.
Optimal Macro-Scheduling
Authors: Samuel T. Chanson, Prem S Sinha
Venue:  (1981)

A multi-class macro-scheduler is described in this paper. The scheduler periodically determines the number of jobs from each class that should be activated to minimize a weighted sum of the mean system residence time without saturating the system. The computation is based on the estimated system workload in the next interval. Thus it is adaptive to workload variation. The service provided to each class (specifically, the mean response time) may be adjusted by changing the weight associated with the job class. .br The scheme is based on mathematical modelling. The solution is obtained through the use of operational analysis method and optimization theory. Exponential smoothing technique is employed to reduce the error of estimating the value of the model parameters. From our simulation results, the scheme appears to be both stable and robust. Performance improvement over some of the $S and the Knee criteria) is significant under some workloads. The overhead involved in its implementation is acceptable and the error due to some of the assumptions used in the formulation and solution of the model are discussed.
Using Multigrid for Semiconductor Device Simulation in 1-D
Authors: Uri Ascher, Stephen E. Adams
Venue:  (1988)

This paper examines the application of the multigrid method to the steady state semiconductor equations in one dimension. A number of attempts reported in the literature have yielded only limited success in applying multigrid algorithms to this sensitive problem, suggesting that a more careful look in relatively simple circumstances is worthwhile. \nSeveral modifications to the basic multigrid algorithm are evaluated based on their performance for a one-dimensional model problem. It was found that use of a symmetric Gauss-Seidel relaxation scheme, a special prolongation based on using the difference operator, and local relaxation sweeps near junctions, produced a robust and efficient code. This modified algorithm is also successful for a wide variety of cases, and its performance compares favourably with other multigrid algorithms that have been applied to the semiconductor equations.
Modern Homotopy Methods in Optimization
Authors: Layne T. Watson, Robert T. Haftka
Venue:  (1988)

Probability-one homotopy methods are a class of algorithms for solving nonlinear systems of equations that are accurate, robust, and converge from an arbitrary starting point almost surely. These new techniques have been successfully applied to solve Brouwer faced point problems, polynomial systems of equations, and discretizations of nonlinear two-point boundary value problems based on shooting, finite differences, collocation, and finite elements. This paper summarizes the theory of globally convergent homotopy algorithms for unconstrained and constrained optimization, and gives some examples of actual application of homotopy techniques to engineering optimization problems.
Nonlinear Thermal Waves: Part II - Analytical Solutions for Pulses
Authors: Mark S. Cramer, Bruce B. Lowekamp, Layne T. Watson
Venue:  (1994)

The weak shock theory developed by Cramer (1994) is used to derive explicit solutions for the evolution of one-dimensional weakly, nonlinear, weakly relaxing heat pulses in rigid conductors. Formulas and differential equations governing the evolution of general heat inputs are derived and applied to the special cases of a square-wave heat input and a finite width sine-wave heat input. Numerical solutions to the exact Maxwell-Cattaneo theory are also presented and show excellent agreement with these analytical solutions.
The Promise (and Reality) of Multidisciplinary Design Optimization
Authors: Susan L. Burgee, Layne T. Watson
Venue:  (1995)

Modern aerospace vehicle design requires the interaction of multiple disciplines, traditionally processed in a sequential order. Multidisciplinary optimization (MDO), a formal methodology for the integration of these disciplines, is evolving towards methods capable of replacing the traditional sequential methodology of aerospace vehicle design by concurrent algorithms, with both an overall gain in product performance and a decrease in design time. This paper discusses the obstacles to MDO, and presents a parallel MDO paradigm using variable-complexity modeling and multipoint response surface approximations for the particular instance of the design of a high speed civil transport (HSCT). This paradigm interleaves the disciplines at one level of complexity, and processes them hierarchically at another level of complexity, achieving parallelism within disciplines, rather than across disciplines. A master-slave paradigm manages a coarse grained parallelism of the analysis and optimization codes required by the disciplines showing reasonable speedups and efficiencies on an Intel Paragon.
Optimal File Sharing in Distributed Networks
Authors: M. Naor, R. M. Roth
Venue:  (1993)

The following file distribution problem is considered: Given a network of processors represented by an undirected graph G = (V,E), and a file size k, an arbitrary file w of k bits is to be distributed among all nodes of G. To this end, each node is assigned a memory device such that, by accessing the memory of its own and of its adjacent nodes, the node can reconstruct the contents of w. The objective is to minimize the total size of memory in the network. This paper presents a file distribution scheme which realizes this objective for k << logD>sub<G>/sub<, where D>sub<G>/sub< stands for the maximum degree in G.
The Raven Kernel: a Microkernel for shared memory multiprocessors
Authors: Stuart Ritchie
Venue:  (1993)

The Raven kernel is a small, lightweight operating system for shared memory multiprocessors. Raven is characterized by its movement of several traditional kernel abstractions into user space. The kernel itself implements tasks, virtual memory management, and low level exception dispatching. All thread management, device drivers, and message passing functions are implemented completely in user space. This movement of typical kernel-level abstractions into user space can drastically reduce the overall number of user/kernel interactions for fine-grained parallel applications.
Improving Genetic Algorithm Efficiency and Reliability in the Design and Optimization of Composite Structures
Authors: Soremekun G., Gurdal Z., Haftka R.T., Watson L.T.
Venue:  (1996)

Genetic algorithms (GAs) often require many iterations for convergence. If the cost for the analysis of each laminate is high, then GA optimization becomes infeasible due to the large amount of CPU time required. A genetic algorithm''s ability to find optimal laminate designs that have complicated stacking sequence patterns in an efficient manner may be improved if the GA takes greater advantage of all the information generated throughout the search scheme. In a standard GA procedure, an elitist method is typically implemented where the worst laminate from the chil population is replaced with the best laminate from the parent population. Valuable information that may exist in other laminates of the parent population is no longer utilized once the child population has been created. The present paper suggests new multiple elitist and variable elitist schemes where more than just the best laminate from the old population may be preserved in successive generations providing the GA with additional laminate designs with good performance. These additional designs may contain pieces of the stacking sequence pattern that are vital for achieving the optimal laminate and help the GA converge more rapidly. Results generated by utilizing the multiple elitist and variable elitist methods have shown to yield richer final populations and minor improvements in the computational cost, while maintaining a high level of reliability.
Understanding Design Patterns with Design Rationale Graphs
Authors: Gail M Elisa Baniassad
Venue:  (2002)

A Design Pattern presents a proven solution to a common design problem using a combination of informal text, diagrams, and examples. Authors of Design Patterns face a difficult task: they must try to convey complex problems and solutions in a comprehensible way to readers of the Pattern. Often, to suitably convey an issue, Pattern authors must spread and repeat information throughout the Pattern. Unfortunately, spreading this information can make it difficult for a reader to grasp subtleties in the design, leading to possible misuses of the Pattern. Design Rationale Graphs (DRG) are intended to help improve a readers comprehension of a Design Pattern by connecting and visualizing related concepts and structural entities in the Pattern. Improved comprehension of a Pattern can aid both the use of the Pattern during implementation, and the reading of code built upon the Pattern. In this paper, we present the Design Rationale Graph tool, which supports the semi-automatic creation of a DRG from a Patterns text, and report on a small, exploratory study conducted to investigate the utility of DRGs. The study showed that readers with access to a DRG for a Pattern were able to answer questions about the Pattern more completely and with more confidence than those given the Design Pattern alone.
VISUALIZING GEOMETRIC UNCERTAINTY OF SURFACE INTERPOLANTS
Authors: Suresh Lodha, Bob Sheehan, Alex Pang, Craig Wittenbrink
Venue:  (1995)

Evaluating and comparing the quality of surface interpolants is an important problem in computer graphics, computer aided geometric design and scientific visualization. We introduce geometric uncertainty as a measure of interpolation error, level of confidence or quality of an interpolant. Geometric uncertainty can be estimated as a scalar or a vector-valued function that depends upon geometric characteristics of interpolants associated with the underlying data. These characteristics include position, normals, isophotes, principal curvatures and directions, mean and Gaussian curvatures. We present several new techniques for visualizing geometric uncertainty of surface interpolants, that combine the strengths of traditional techniques such as pseudo-coloring, differencing, overlay, and transparency with new glyph and texture-based techniques. The viewer can control an interactive query-driven toolbox to create a wide variety of graphics that allow probing of geometric information in useful and convenient ways. We demonstrate the effectiveness of these techniques by visualizing geometric uncertainty of surfaces obtained by different interpolation techniques -- bilinear, $C^0$ linear, $C^2$ bicubic B-spline, multiquadrics, inverse multiquadrics and thin plate splines.
Extending Cassandra
Authors: I. D. Craig
Venue:  (1991)

In this paper, I record a number of extensions to my CASSANDRA architecture. Many of these extensions formed part of the original conception. Since the original architecture definition was published, these extensions have become more pressing. In particular, I argue that the speech act model can be used to great effect by DAI systems, and I have also indicated the variety of ways in which reflective reasoning can be used. The remarks on reflection are founded on work that I have done already on this topic. The extensions form the next stage of the development of the CASSANDRA architecture.
Probabilistic Solitude Detection I: Ring Size Known Approximately
Authors: Karl Abrahamson, Andrew Adler, Lisa Higham, David G. Kirkpatrick
Venue:  (1987)

Matching upper and lower bounds for the bit complexity of a problem on asynchronous unidirectional rings are established, assuming that algorithms must reach a correct conclusion with probability $1 - \epsilon$, for some $\epsilon < 0$. Processors can have identities, but the identities are not necessarily distinct. The problem is that of a distinguished processor determining whether it is the only distinguished processor. The complexity depends on the processors'' knowledge of the size $n$ of the ring. When no upper bound is known, only nondistributive termination is possible, and $\Theta (n \log (1 / \epsilon)) $ bits are necessary and sufficient. When only an upper bound $N$ is known, distributive termination is possible, but the complexity of achieving distributive termination is $ \Theta (n \sqrt{\log ( \frac{N}{n})} + n \log (\frac{1}{\epsilon}))$. When processors know that $(\frac{1}{2} + \rho)N \leq n \leq N$ for $\rho < 0$, then the bound drops to $\Theta (n \log \log (\frac{1}{\epsilon}) + n \log (\frac{1}{\rho}))$, for both distributive and nondistributive termination, for sufficiently large $N$.
The Potential to Improve Retrieval Effectiveness with Multiple Viewpoints
Authors: Allison L. Powell, James C. French
Venue:  (1998)

We propose that providing multiple viewpoints of a document collection and allowing users to move among these viewpoints during a search or browse session will facilitate the location of useful documents. In this paper, we present the results of preliminary experiments that illustrate the potential benefits of this approach. These experiments utilize a full text view and a manually assigned topic descriptor view. We propose a measure for determining the amount of agreement among topic descriptors assigned to documents and show results for the TREC SJMN and ZIFF collections. For those same collections, we then show the potential retrieval improvement when the two viewpoints are utilized.
Photometric Stereo: Lambertian Reflectance and Light Sources with Unknown Direction and Strength
Authors: R. J. Woodham, Y. Iwahori, Rob A. Barman
Venue:  (1991)

This paper reconsiders the familiar case of photometric stereo under the assumption of Lambertian surface reflectance and three distant point sources of illumination. Here, it is assumed that the directions to and the relative strengths of the three light sources are not known {\it a priori}. Rather, estimation of these parameters becomes part of the problem formulation. \nEach light source is represented by a 3-D vector that points in the direction of the light source and has magnitude proportional to the strength of the light source. Thus, nine parameters are required to characterize the three light sources. It is shown that, regardless of object shape, triples of measured intensity values are constrained to lie on a quadratic surface having six degrees of freedom. Estimation of the six parameters of the quadratic surface allows the determination of the nine parameters of the light sources up to an unknown rotation. \nThis is sufficient to determine object shape, although attitude with respect to the world-based or the camera-based coordinate system can not be simultaneously recovered without additional information.
Exploiting the Map Metaphor in a Tool for Software Evolution
Authors: William G. Griswold, Jimmy J. Yuan, Yoshikiyo Kato
Venue:  (2000)

Software maintenance and evolution are the dominant activities in the software lifecycle. Modularization can allow design decisions to be independently evolved, but eventually modularizations fail to do so, and then complicated global changes are required. Tool support can reduce the costs of these unfortunate changes, but current tools are limited in their ability to manage information for large-scale software evolution. In this paper we argue that the map metaphor can serve as an organizing principle for the design of effective tools for performing global software changes. We describe the design of Aspect Browser, developed around the map metaphor, and discuss a case study of removing a feature from a 500,000 line program written in Fortran and C.
Introduction to the SUIF 2.0 Compiler System
Authors: Holger Kienle, Urs Holzle
Venue:  (1997)

We give a brief overview of the new SUIF 2.0 compiler system which is currently being developed by the Stanford Compiler Group. We describe the SUIF 2.0 libraries at a very high level, focusing on the concepts without going into the gory details of the interfaces and the implementation.
The Natural Work-Stealing Algorithm is Stable
Authors: Petra Berenbrink, Tom Friedetzky, Leslie A Goldberg
Venue:  (2001)

In this paper we analyse a very simple dynamic work-stealing algorithm. In the work-generation model, there are n generators which are arbitrarily distributed among a set of n processors. The distribution of generators is arbitrary --- generators may even move at the beginning of each time step. During each time-step, each generator may generate a unit-time task which it inserts into the queue of its host processor. It generates such a task independently with probability lambda. After the new tasks are generated, each processor removes one task from its queue and services it. Clearly, the work-generation model allows the load to grow more and more imbalanced, so, even when lambda>1, the system load can be unbounded. The natural work-stealing algorithm that we analyse is widely used in practical applications and works as follows. During each time step, each empty processor (with no work to do) sends a request to a randomly selected other processor. Any non-empty processor having received at least one such request in turn decides (again randomly) in favour of one of the requests. The number of tasks which are transferred from the non-empty processor to the empty one is determined by the so-called work-stealing function f. In particular, if a processor that accepts a request has l tasks stored in its queue, then f(l) tasks are transferred to the currently empty one. A popular work-stealing function is f(l)=floor(l/2), which transfers (roughly) half of the tasks. We analyse the long-term behaviour of the system as a function of lambda and f. We show that the system is stable for any constant generation rate lambda>1 and for a wide class of functions f. Most intuitively sensible functions are included in this class (for example, every function f(l) which is omega(1) as a function of l is included). We give a quantitative description of the functions f which lead to stable systems. Furthermore, we give upper bounds on the average system load (as a function of f and n). Our proof techniques combine Lyapunov function arguments with domination arguments, which are needed to cope with dependency.