ppxscal/embedding_network huggingface dataset:
Configuration and Dynamic Reconfiguration of Component-Based Applications with Microsoft .NET
Authors: Andreas Rasche, Andreas Polze
Venue: Proceedings of the Sixth IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (2003)

Dynamic reconfiguration provides of powerful mechanism to adapt component-based distributed applications to changing environmental conditions. We have designed and implemented a framework for dynamic component reconfiguration on the basis of the Microsoft. NET environment.Within this paper we present an experimental evaluation of our infrastructure for dynamic reconfiguration of component-based applications. Our framework supports the description of application configurations and profiles and allows for selection of a particular configuration andobject/component instantiation based on measured environmental conditions. In response to changes in the environment, our framework will dynamically load new configurations, thus implementing dynamic reconfiguration of an application. Configuration code for components and applications has to interact with many functional modules and therefore is often scattered around the whole application. We use aspect-oriented programming techniques to handle configuration aspects separately from functional code.The timing behavior of dynamic reconfiguration depends heavely on properties of the underlying programming environment and the operating system. We have studied to which extend and with which performance impact the Microsoft. NET Platform1 supports dynamic reconfiguration. The paper thoroughly discusses our experimental results.
Residual fault density prediction using regression methods
Authors: J. A. Morgan, G. J. Knafl
Venue: Proceedings of the The Seventh International Symposium on Software Reliability Engineering (1996)

Regression methods are used to model residual fault density in terms of several product and testing process measures. Process measures considered include discovered fault density, test set size and various coverage measures such as block, decision and all-uses coverage. Product measures considered include lines of code as well as block, decision and all-uses counts. The relative importance of these product/process measures for predicting residual fault density is assessed for a specific data set. Only selected testing process measures, in particular discovered fault density and decision coverage, are important predictors in this case while all product measures considered are important. These results are based on consideration of a substantial family of models, specifically, the family of quadratic response surface models with two-way interaction. Model selection is based on "leave one out at a time" cross-validation using the predicted residual sum of squares (PRESS) criterion.
A Methodology of Simple Models
Authors: Mark Smotherman, Kishor Trivedi
Venue:  (1985)

The use of complex reliability models may not be cost-effective in all phases of the evaluation of a fault-tolerant system. However, in the absence of a methodology, the simple models that are used instead can only be selected on an informal basis. Simple models thus yield reliability predictions that have an unknown relationship to the actual system reliability; they may be monotonically conservative or optimistic, or the quality of their predictions may vary with mission time or other model parameters. We present a methodology of simple models in which the reliability predictions are provably conservative or optimistic. This methodology forces the reliability analyst to consider the effects on the reliability of model assumptions, and provides a preliminary form of sensitivity analysis. The reliability predictions that result are bands, not single numbers. We present an application of the methodology to the FTMP and SIFT fault-tolerant computer systems.
Farthest Neighbors, Maximum Spanning Trees and Related Problems in Higher Dimensions
Authors: K P Agarwal, Jiri Matousek, Subhash Suri
Venue:  (1991)

\indent We present a randomized algorithm of expected time complexity \[ O(m^{2/3} n^{2/3}\, \mbox {log} ^ {4/3} m + m \,\mbox {log}^{2}\, m + n \, \mbox{log}^{2}\, n) \] for computing bi-chromatic farthest neighbors between $n$ red points and $m$ blue points in ${\cal E} ^{3}$. The algorithm can also be used to compute all farthest neighbors or external farthest neighbors of $n$ points in ${\cal E } ^{3}$ in $O(n^{4/3} \, \mbox {log}^{4/3} n)$ expected time. Using these procedures as building blocks, we can compute a Euclidean maximum spanning tree or a minimum-diameter two-partition of $n$ points in ${\cal E } ^{3}$ in $O(n^{4/3} \, \mbox {log} ^{7/3}\, n)$ expected time. The previous best bound for these problems was $O(n ^{3/2} \, \mbox {log} ^ {1/2} \, n)$. Our algorithms can be extended to higher dimensions. We also propose fast and simple approximation algorithms for these problems. These approximation algorithms produce solutions that approximate the true value with a relative accuracy $\varepsilon$ and run in time $O(n\varepsilon ^{(1-k)/2} \, \mbox {log} \, n)$ or $O(n\varepsilon ^{(1-k)/2} \, \mbox {log} ^{2} \, n)$ in $k$-dimensional space.
Migration Transparency in Agent Systems
Authors: B. Schulze, E. R. M. Madeira
Venue: Proceedings of the The Fourth International Symposium on Autonomous Decentralized Systems (1999)

Migration distribution transparency is considered in the context of multi-agent systems. A mobile agent architecture is proposed with an availability service and a transparency interface. Transparent mobility of agents is explored in applications using overall balancing of resources. The search for a new destination agency follows a transparent location and selection. Final balancing takes place at the level of requests and callbacks. Transparency is goal oriented.
Excited States in 4He Described By a Shadow Wave Function: Rotons and Vortices
Authors: W. Wu, S. A. Vitiello, L. Reatto, M. H. Kalos
Venue:  (1990)

The idea of the shadow wave function, which incorporates quantum delocalization of particles into the description of quantum liquids and solids, is applied to excited states of liquid 4He. With a simple Feynman shadow wave function, we compute the phonon-roton excitation spectrum by a Monte Carlo method at three different densities. The variation of the excitation energy with density is consistent with the behavior of the experimental data. The energy near the roton minimum is an excellent agreement with experiment at all densities. By using shadow variables, we show that we can describe a vortex with distributed vorticity with either a hollow or a filled core.
Towards an Application Framework for Automated Planning and Scheduling
Authors: A. Fukunaga, G. Rabideau, S. Chien, D. Yan
Venue:  (1996)

A number of successful applications of automated planning and scheduling applications to spacecraft operations have recently been reported in the literature. However, these applications have been one-of-a-kind applications that required a substantial amount of development effort. In this paper, we describe ASPEN (Automated Planning/Scheduling Environment), a modular, reconfigurable application framework which is capable of supporting a wide variety of planning and scheduling applications. We describe the architecture of ASPEN, as well as a number of current spacecraft control/operations applications in progress.
The Sorting of Points Along an Algebraic Curve
Authors: John K. Johnstone
Venue:  (1987)

The area of geometric modeling is concerned with the creation of computationally efficient models of solid physical objects to facilitate their design, assembly, and analysis. In a geometric modeling system, a solid such as a robot hand or a coffee cup is modeled by a collection of points, curves, and surfaces. The sorting of points along an algebraic curve is an operation that arises frequently during the creation and manipulation of geometric models. This thesis presents a thorough investigation of sorting, including an evaluation of the two conventional methods of sorting and the presentation of a new and superior method.
Using manually-built web directories for automatic evaluation of known-item retrieval
Authors: Steven M. Beitzel, Eric C. Jensen, Abdur Chowdhury, David Grossman, Ophir Frieder
Venue: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval (2003)

Information retrieval system evaluation is complicated by the need for manually assessed relevance judgments. Large manually-built directories on the web open the door to new evaluation procedures. By assuming that web pages are the known relevant items for queries that exactly match their title, we use the ODP (Open Directory Project) and Looksmart directories for system evaluation. We test our approach with a sample from a log of ten million web queries and show that such an evaluation is unbiased in terms of the directory used, stable with respect to the query set selected, and correlated with a reasonably large manual evaluation.
Bunch: A Clustering Tool for the Recovery and Maintenance of Software System Structures
Authors: S. Mancoridis, B. S. Mitchell, Y. Chen, E. R. Gansner
Venue: Proceedings of the IEEE International Conference on Software Maintenance (1999)

Software systems are typically modified in order to extend or change their functionality, improve their performance, port them to different platforms, and so on. For developers, it is crucial to understand the structure of a system before attempting to modify it. The structure of a system, however, may not be apparent to new developers, because the design documentation is non-existent or, worse, inconsistent with the implementation. This problem could be alleviated if developers were somehow able to produce high-level system decomposition descriptions from the low-level structures present in the source code.We have developed a clustering tool called Bunch that creates a system decomposition automatically by treating clustering as an optimization problem. This paper describes the extensions made to Bunch in response to feedback we received from users. The most important extension, in terms of the quality of results and execution efficiency, is a feature that enables the integration of designer knowledge about the system structure into an otherwise fully automatic clustering process. We use a case study to show how our new features simplified the task of extracting the subsystem structure of a medium size program, while exposing an interesting design flaw in the process.
Lattice Field Theory on Cluster Computers: Vector- Vs. Cache-Centric Programming
Authors: C. Best, M. Peardon, N. Eicker, P. Uberholz, T. Lippert, K. Schilling
Venue: Proceedings of the 1st IEEE Computer Society International Workshop on Cluster Computing (1999)

We evaluate the possibility of moving medium-sized calculation in lattice field theory from vector supercomputers to cluster computers, namely clusters built from Alpha processors and Myrinet interconnect, and find that a medium-sized system with a performance of 10 to 20 GFlop/scan be easily and cost-effectively built from current off-the-shelf components. The performance of the algorithms is analyzed with respect to memory bandwidth problems by experiment and using a cache simulator that uses C++ operator overloading. It seems that cluster systems, while hampered by poor memory bandwidth as compared to supercomputers, might offer opportunities for some algorithms that have good locality but are not vectorizable and thus will not perform well on vector systems.
A High Assurance On-line Recovery Technology for a Space On-board Computer
Authors: Hiroyuki Yashiro, Teruo Fujiwara, Kinji Mori
Venue: Proceedings of the Fifth International Symposium on Autonomous Decentralized Systems (2001)

A high assurance on-line recovery technology for a space on-board computer that can be realized using commercial devices is proposed whereby a faulty processor node confirms its normality and then recovers without affecting the other processor nodes in operation. Also, the result of an evaluation test using the breadboard model (BBM) implementing this technology is reported. Because this technology enables simple and assured recovery of a faulty processor node regardless of its degree of redundancy, it can be applied to various applications, such as a launch vehicle, a satellite, and a reusable space vehicle. As a result, decreasing the cost of an on-board computer is possible while maintaining its high reliability.
An Open Real-Time Environment for Parallel and Distributed Systems
Authors: Tei-Wei Kuo, Kwei-Jay Lin, Yu-Chung Wang
Venue: Proceedings of the The 20th International Conference on Distributed Computing Systems ( ICDCS 2000) (2000)

Most computer-based systems have hard real-time constraints. Schedulers in complex systems must be designed to manage a set of applications developed and deployed independently. In this paper, we study open real-time environment architecture for distributed systems where real-time applications may run concurrently with non-real-time applications. The architecture uses a two-level scheduling scheme. Each application is assigned a sporadic server to schedule the processes in the application. A system-wide fixed priority scheduler then schedules all sporadic servers. Using the proposed open environment architecture, all hard real-time applications are guaranteed to have their reserved CPU utilization in order to meet all their deadlines. The guarantee is independent of the behaviors of all other applications in the same system. We present the schedulability analysis methods on systems with or without shared memory.
Linear Semibridging Carbonyls 4. Creations of Steric Crowding and Harbingers of Strong Metal-to-Metal Bonding
Authors: Charles Q. Simpson,  II, Michael B. Hall
Venue:  (1991)

Ab initio full-gradient geometry optimizations have been performed on 28 of 36 M-M closed-shell electronic configurations for the M2(CO)2 (M=Sc or Mn) model system. Those configurations whose energy favors a bridging carbonyl structure always prefer a bent semibridging or symmetrically bridging geometry. Conversely, when the carbonyls, of those configurations whose energy favors terminal carbonyls, are forced into bridging sites, a linear semibridging structure results. Thus, linear semibridging carbonyls are a result of steric crowding. Generally, those configurations that favor a bent semibridging carbonyl have more metal-to-metal antibonding molecular orbitals occupied. In contract, those configurations that favor a terminal structure, and hence, a linear semibridging carbonyl in sterically crowded molecules, have more metal-to-metal bonding orbitals occupied. Thus, the appearance of linear semibridging carbonyls harbingers strong metal-to-metal bonding.
How to Explore your Opponent's Strategy (almost) Optimally
Authors: David Carmel, Shaul Markovitch
Venue: Proceedings of the 3rd International Conference on Multi Agent Systems (1998)

This work presents a lookahead-based exploration strategy for a model-based learning agent that enables exploration of the opponent's behavior during interaction in a multi-agent system. Instead of holding one model, the model-based agent maintains a mixed opponent model, a distribution over a set of models that reflects its uncertainty about the opponent's strategy. Every action is evaluated according to its long run contribution to the expected utility and to the knowledge regarding the opponent's strategy. We present an efficient algorithm that returns an almost optimal exploration strategy against a given mixed model, and a learning method for acquiring a mixed model consistent with the opponent's past behavior. We report experimental results in the Iterated Prisoner's Dilemma game that demonstrate the superiority of the lookahead-based exploration strategy over other exploration methods.
Compiler Support for Data Forwarding in Scalable Shared-Memory Multiprocessors
Authors: David Koufaty, Josep Torrellas
Venue: Proceedings of the 1999 International Conference on Parallel Processing (1999)

As the difference in speed between processor and memory system continues to increase, it is becoming crucial to develop and refine techniques that enhance the effectiveness of cache hierarchies. One promising technique in the context of scalable shared-memory multiprocessors is data forwarding. Forwarding hides the latency of communication-induced misses by having producer processors send data to the caches of potential consumer processors in advance. Forwarding can hide the latency effectively, has low instruction overhead, and uses few machine resources.This paper presents a complete implementation of a data forwarding pass in an industrial-strength parallelizing compiler. Complete Fortran applications are analyzed for dependences and, based on the analysis, automatically annotated with forwarding directives. We propose a forwarding framework that includes 4 new instructions: write-forward, write-broadcast, write-update}, and write-through. New micro-architectural support is proposed.In our analysis, we assume that the assignment of loop iterations to processors is known. We perform simulations of multiprocessors with different cache, memory, machine sharing, and process migration parameters. We conclude that data forwarding delivers large speedups (six 32-processor applications ran an average of 40% faster), gets close to the upper bound in performance, and needs compiler support of only medium complexity.
Parallel Spatial Joins Using Grid Files
Authors: Jin-Deog Kim, Bong-Hee Hong
Venue: Proceedings of the Seventh International Conference on Parallel and Distributed Systems (2000)

The most costly spatial operation in spatial databases is a spatial join, which combines objects from two data sets based on spatial predicates. Even if the execution time of sequential processing of a spatial join has been considerably improved over the last few years, the response time is far from meeting the requirements of interactive users. In this paper, we have developed two kinds of parallel spatial join algorithms based on grid files: a parallel spatial join using a multi-assignment grid file and a parallel spatial join using a single-assignment grid file. We also present the cost of the two join algorithms in terms of the number of MBR comparisons. The experimental tests on the MIMD parallel machine with shared disks show that the first join algorithm based on disjoint decomposition of a data space outperforms the second based on non-disjoint decomposition.
Unification of finite failure non-homogeneous Poisson process models through test coverage
Authors: S. S. Gokhale, T. Philip, P. N. Marinos, K. S. Trivedi
Venue: Proceedings of the The Seventh International Symposium on Software Reliability Engineering (1996)

A number of analytical software reliability models have been proposed for estimating the reliability growth of a software product. We present an Enhanced Non-Homogeneous Poisson Process (ENHPP) model and show that previously reported Non-Homogeneous Poisson Process (NHPP) based models, with bounded mean valve functions, are special cases of the ENHPP model. The ENHPP model differs from previous models in that it incorporates explicitly the time varying test coverage function in its analytical formulation, and provides for defective fault detection and test coverage during the testing and operational phases. The ENHPP model is validated using several available failure data sets.
Virtual Lunar Landscapes for Testing Vision-Guided Lunar Landers
Authors: Iain Martin
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

Virtual reality techniques are being used to support the development of unmanned space-probes intended to land on other planets in the solar system. These planetary landers will operate autonomously during landing and will use vision for navigation and guidance down to a safe landing spot. Suitable vision techniques have been developed but must be extensively tested on realistic test surfaces. A system (LunarSim) for producing realistic simulations of heavily cratered planetary surfaces has been developed to support exhaustive testing of vision guidance software.This paper begins by describing the reasons for developing a realistic simulation of the lunar surface. The techniques that have been used to produce models of impact craters are then described. A description of the LunarSim software is provided and an example is presented of an image sequence produced using LunarSim. Finally a summary of related current and future work is given.
Calculation of Pseudospectra by the Arnoldi Iteration
Authors: Kim Toh, Lloyd N. Trefethen
Venue:  (1994)

The Arnoldi iteration, usually viewed as a method for calculating eigenvalues, can also be used to estimate pseudospectra. This possibility may be of practical importance, for in applications involving highly non-normal matrices or operators, such as hydrodynamic stability, pseudospectra may be physically more significant than spectra.
Evaluating Visualizations Based on the Performed Task
Authors: James H. Garrett Jr
Venue: Proceedings of the International Conference on Information Visualisation (2000)

This paper describes an ongoing project with the goal of designing and implementing a method to evaluate visualizations based on the tasks supported. The method evaluates time to perform the task and the quality of the user solution. This method is described in detail in this paper.A software tool, which uses visualization to support users performing environmental analysis, was used to test the first version of this method. The software tool evaluated helps users to perform the computations of environmental impacts of two products. Two versions of the same software tool were used. The first version uses interactive tables and the second version displays the information using different types of interactive visualizations.The software tool was evaluated with users solving a task, which consists of selecting a product from two alternatives based on environmental parameters. The users were divided into two groups. Each group of users solved the same task but they were using different software tools. A summary of findings and future research is presented at the end of this paper.
Trust Metrics, Models and Protocols for Electronic Commerce Transactions
Authors: Daniel W. Manchala
Venue: Proceedings of the The 18th International Conference on Distributed Computing Systems (1998)

This paper introduces the notion of quantifiable trust for electronic commerce. It describes metrics and models for the measurement of trust variables and fuzzy verification of transactions. Trust metrics help preserve system availability by determining risk on transactions. Fur-thermore, when several entities are involved in elec-tronic transactions, previously know techniques are ap-plied for trust propagation. Malicious transacting enti-ties may try to illegitimately gain access to private trust information. Suitable protocols are developed to mini-mize breach of privacy and incorporate a non-repudiable context using cryptographic techniques.
Experiences in teaching computing theory via aspects of problem-based learning
Authors: Margaret Hamilton, James Harland, Lin Padgham
Venue: Proceedings of the fifth Australasian conference on Computing education - Volume 20 (2003)

Computing Theory is a compulsory subject that many computer science students find difficult, and for which there is a wide range of abilities and backgrounds amongst students. In this paper we describe the evolution of this subject at our university over the past decade, which has resulted in a much more student-centred approach to learning. This has not only enhanced the learning experience of the students but also has simplified the development of teaching modes and resources involving on-line replacements for lectures.