ppxscal/embedding_network huggingface dataset:
The Role of Order in Distributed Programs
Authors: Keith Marzullo, Kenneth P. Birman
Venue:  (1989)

We discuss the role of order in building distributed systems. It is our belief that a ``principle of event ordering'''' underlies the wide range of operating systems mechanisms that have been put forward for building robust distributed software. Stated concisely, this principle is that one achieves correct distributed behavior by ordering classes of distributed events that conflict with one another. By focusing on order, one can obtain simplified descriptions and convincingly correct solutions to problems that might otherwise have looked extremely complex. Moreover, we observe that there are a limited number of ways to obtain order, and that the choice made impacts greatly on performance.
Feature Sets Evaluation for Handwritten Word Recognition
Authors: José J. de Oliveira Jr., João M. de Carvalho, Cinthia O. de A. Freitas, Robert Sabourin
Venue: Proceedings of the Eighth International Workshop on Frontiers in Handwriting Recognition (IWFHR'02) (2002)

This work presents a baseline system used to evaluate feature sets for word recognition. The main goal is to determine an optimum feature set to represent the handwritten names for the months of the year in Brazilian Portuguese language. Three kinds of features are evaluated: perceptual, directional and topological. The evaluation shows that taken in isolation, the perceptual feature set produces the best results for the lexicon used. These results can be further improved combining the feature sets. The baseline system developed obtains an average recognition rate of 87%. This can be considered a good result considering that noexplicit segmentation is performed.
RECONSTRUCTION OF MULTIPLE CRACKS FROM EXPERIMENTAL ELECTROSTATIC BOUNDARY MEASUREMENTS
Authors: Kurt Bryan, Valdis Liepa, Michael Vogelius
Venue:  (1993)

This paper describes an algorithm for recovering a collection of linear cracks in a homogeneous electrical conductor from boundary measurements of voltages induced by specified current fluxes. The technique is a variation of Newton''s method and is based on taking weighted averages of the boundary data. We also describe an apparatus that was constructed specifically for generating laboratory data on which to test the algorithm. We apply the algorithm to a number of different test cases and discuss the results.
Analysis of NK-xor landscapes
Authors: Cees H.M. Kemenade
Venue:  (1998)

The NK-xor landscapes are a class of optimization problems with adjustable ruggedness of its fitness landscape.
A society of cooperative agents on the information network: towards intelligent information gathering
Authors: R. Okada, Eun-Seok Lee, N. Shiratori
Venue: Proceedings of the 1995 International Conference on Network Protocols (1995)

Proposes a completely agent-based approach for information gathering on information networks with a large number of distributed heterogeneous sources, such as Internet. Locating and accessing information in such a large distributed system which changes dynamically is challenging. An agent-based solution is the most suitable in such situations. We first review the drawbacks of existing non-agent and partially agent-based solutions for locating information on Internet. We introduce a CAS model to express a Society of Cooperative Agents and then explain how our completely agent based solution based on the proposed CAS model overcomes the weak points of existing approaches
An Empirical Study of Experience-Based Software Defect Content Estimation Methods
Authors: Håkan Petersson, Claes Wohlin
Venue: Proceedings of the 10th International Symposium on Software Reliability Engineering (1999)

Capture-recapture models and curve-fitting models have been proposed to estimate the remaining number of defects after a review. This estimation gives valuable information to monitor and control software reliability. However, the different models provide different estimates making it difficult to know which estimate is the most accurate. One possible solution is to, as in this paper, focus on different opportunities to estimate intervals. The study is based on thirty capture-recapture data sets from software reviews. Twenty of the data sets are used to create different models to perform estimation. The models are then evaluated on the remaining ten data sets. The study shows that the use of historical data in model building is one way to overcome some of the problems experienced with both capture-recapture and curve-fitting models, to estimate the defect content after a review.
Mac OS X Security
Authors: Bruce Potter, Preston Norvell, Brian Wotring
Venue:  (2003)

:Mac OS X now operates on a UNIX engine. As such it is much more powerful than previous operating systems. It is now a multitasking, multithreaded, multi-user, and multiprocessor system with enhanced interoperability with other systems. Along with that increased power comes increased security vulnerability. Part I introduces readers to the basics of OS X security. Part II addresses system security beginning at the client workstation level. This section addresses UNIX-specific information such as permissions, executables, and network protocols and the related security concerns. Part III covers network security. The chapters in this section will cover security for internet services, file sharing, and network protection systems. Part IV addresses enterprise security using a variety of tools (Kerberos, NetInfo, and Rendezvous) as well as workstation configurations to illustrate how OS X Server and OS X inter-operate. The final section addresses auditing and forensics and what to do when an OS X network is compromised. This section teaches readers to audit systems painlessly and effectively and how to investigate and handle incidents.
Techniques of Maintaining Evolving Component-Based Software
Authors: Ye Wu, Dai Pan, Mei-Hwa Chen
Venue: Proceedings of the International Conference on Software Maintenance (ICSM'00) (2000)

Component-based software engineering has been increasingly adopted for software development. Such an approach using reusable components as the building blocks for constructing software, on one hand, embellishes the likelihood of improving software quality and productivity; on the other hand, it consequently involves frequent maintenance activities, such as upgrading third party components or adding new features. The cost of maintenance for conventional software can account for as much as two-thirds of the total cost, and it can likely be even more for maintaining component-based software. Thus, an effective maintenance technique for component-based software is strongly desired. In this paper, we present a technique that can be applied on various maintenance activities over component-based software systems. The technique proposed utilizes a static analysis to identify the interfaces, events and dependence relationships that would be affected by the modification in the maintenance activity. The results obtained from the static analysis along with the information of component interactions recorded during the execution of each test case are used to guide test selection in the maintenance phase. The empirical results show that with 19% effort our technique detected 71% of the faults in an industrial component-based system, which demonstrates the great potential effectiveness of the technique.
Tree balance and node allocation
Authors: Yangjun Chen, W. Benn
Venue: Proceedings of the 1997 International Symposium on Database Engineering & Applications (1997)

We consider the query evaluation problem in multidatabases and develop an algorithm for generating optimal plans for queries submitted to an integrated schema. We try to extend the basic transformation step used in the method proposed by (Du et al., 1994) and construct a dynamic time table to support a query optimization process. In this way, not only the join tree balance, but also the node allocation can be achieved according to both communication costs and load measurements. In addition, the queuing analysis has been utilized to estimate the response times of local database systems.
Bimodal Multicast (revised)
Authors: Kenneth P. Birman, Mark Hayden, Oznur Ozkasap, Zhen Xiao, Mihai Budiu, Yaron Minsky
Venue:  (1999)

There are many methods for making a multicast protocol "reliable". At one end of the spectrum, a reliable multicast protocol might offer atomicity guarantees, such as all-or-nothing delivery, delivery ordering, and perhaps additional properties such as virtually synchronous addressing. At the other are protocols that use local repair to overcome transient packet loss in the network, offering ''best effort'' reliability. Yet none of this prior work has treated stability of multicast delivery as a basic reliability property, such as might be needed in an internet radio, TV, or conferencing application. This paper looks at reliability with a new goal: development of a multicast protocol which is reliable in a sense that can be rigorously quantified and includes throughput stability guarantees. We characterize this new protocol as a "bimodal multicast" in reference to its reliability model, which corresponds to a family of bimodal probability distributions. Here, we introduce the protocol, provide a theoretical analysis of its behavior, review experimental results, and discuss some candidate applications. These confirm that bimodal multicast is reliable, scalable, and that the protocol provides remarkably stable delivery throughput.
Matrix Iterations: The Six Gaps Between Potential Theory and Convergence
Authors: Tobin A. Driscoll, Kim Toh, Lloyd N. Trefethen
Venue:  (1996)

The theory of the convergence of Krylov subspace iterations for linear systems of equations (conjugate gradients, biconjugate gradients, GMRES, QMR, Bi-CGSTAB, ...) is reviewed. For a computation of this kind, an estimated asymptotic convergence factor rho > 1 can be derived by solving a problem of potential theory or conformal mapping. Six approximations are involved in reducing the actual computation to this scalar estimate. These six approximations are discussed in a systematic way and illustrated by a sequence of examples computed with tools of numerical conformal mapping and semidefinite programming.
Ilona: An advanced CAI Tutorial System for the Fundamentals of Logic
Authors: Otto Mayer, Graham E. Oberem, Fillia Makedon
Venue:  (1991)

An advanced tutorial system for teaching the fundamentals of logic has been developed to run on UNIX work stations and commonly available micro-computers. An important part of this tutorial is the intelligent problem solving environment which allows students to practise wiriting logical sentences in mathematical notation. A natural language system for intelligent logic narrative analysis (ILONA) allows students to type in their own logical sentences in plain English and then have the computer check their working when they write these in mathematical form. ILONA is an intelligent tutoring system which allows students a great deal of initiative in problem solving and provides a degree of flexibility in answer evaluation not found in traditional CAI systems. The concepts and structures used in the development of ILONA are easily transferable to other domains.
Dynamic maintenance of the virtual path layout
Authors: O. Gerstel, A. Segall
Venue: Proceedings of the Fourteenth Annual Joint Conference of the IEEE Computer and Communication Societies (Vol. 1)-Volume - Volume 1 (1995)

Discusses methods for adjusting the layout of virtual paths in an ATM network, to the dynamics of changes in the usage of the network by its end-users. The authors first present a centralized algorithm for finding a better layout for the current traffic pattern, and for applying the change in the network, and discuss its drawbacks. They then present a distributed algorithm that emulates the centralized algorithm with a much lower overhead, and enhanced durability to faults. They prove that both algorithms produce identical layouts, thus showing the superiority of the latter algorithm. Both algorithms base the changes in the network on a new rerouting protocol, which does not cause any losses in data, nor changes in the FIFO order of cells.
Note on Conditional Compilation in Standard ML
Authors: Nicholas Haines, Edoardo Biagioni, Robert Harper, Brian G. Milnes
Venue:  (1993)

Keywords: Standard ML, modules, functors, conditional compilation, code style, optimzing compilers 7 pages [FTP: CMU-CS-93-172.ps] In the Fox project we make frequent use of conditional code within Standard ML functors: code which depends on the functor arguments. The canonical example is instrumentation code for testing or debugging, only present when flags in the functor arguments are set. We would like the object code of instantiations of these functors to be as efficient as possible, i.e., to omit the code when the argument flags are not set. This note considers compilation techniques to achieve this goal, and code styles which do well in the absence of such techniques.
Schwarz-Christoffel Mapping in the 1980''s
Authors: Lloyd N. Trefethen
Venue:  (1993)

An informal survey is presented of the numerical computation of Schwarz-Christoffel maps (i.e., conformal maps from a disk in the complex plane to a polygon) and their applications in science and engineering. It is shown that many superficially different problems of conformal mapping and potential theory can be reduced to Schwarz-Christoffel maps and then solved by software such as the Fortran package SCPACK. This report, not for publication, is a reproduction of a 1989 technical report from the Department of Mathematics at the Massachusetts Institute of Technology.
Page Table Management in Local/Remote Architectures
Authors: A M Holliday
Venue:  (1988)

We conjecture that a paged memory with page migration by the operating system may be an effective system environment for a local/remote shared memory architecture executing a single parallel computation. Implementing a paged memory in such an architecture raises several issues with respect to page table management. These issues include page table placement, page table replication level, and page table storage overhead. We discuss these issues, propose alternative solutions, and present an experimental evaluation of the solutions. The experiments were conducted using software-implemented page tables on two versions of a 32-node BBN Butterfly $^{TM}$. The experiments have investigated the case of a single shared-memory parallel computation with one user process per processor. The implementation captures the costs of page table entry locking and reference information updating. Each user process has a copy of the computation''s code and non-shared variables in local memory. Only shared data references use the page tables. A separate processor has a migration daemon that periodically unblocks itself and examines the page tables to make policy decisions concerning page migration. The conclusions drawn include that: 1) a fully replicated page-indexed page table significantly reduces network, memory, and lock contention in comparison to a single copy, 2) a fully replicated page-indexed page table faces a severe memory utilization problem in large-scale architectures (in fact, bounding the size of the system), and 3) a proposed approach based on inverted page tables appears to be a promising alternative to a fully replicated page-indexed page table.
An Analysis of Architectural Visual Reasoning in Conceptual Sketching via Computational Sketch Analysis (CSA)
Authors: J. Mcfadzean
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

Visual reasoning in design is facilitated by sketching. This research investigates how designers sketch, specifically analysing the physical details of mark making. It relates the graphical representations to the abstract cognitive processes of architectural design. A new form of protocol analysis has been developed using video and computer records of designers' sketching activity. The analysis of the resulting data compares the designer's retrospective commentary and interpretations of the sketching activity with the computer's record of that activity. The analysis will lead to a greater understanding of the relationships between 'Design Events' and 'Graphical Events' and thus how the notational activity of sketching supports the cognitive activity of conceptual design.
Extending Programming By Demonstration With Hierarchical Event Histories
Authors: David S. Kosbie, Brad A. Myers
Venue:  (1994)

Keywords: Programming by demonstration, hierarchical event histories, application interface, user interfaces, intelligent interfaces, end-user programming [Also appears as Human-Computer Interaction Institute Technical Report CMU-HCII-94-102] [FTP: CMU-CS-94-156.ps] Programming by Demonstration, or PBD, is an exciting and developing branch of HCI research. With PBD techniques, end-users can add functionality to their environments without programming in the conventional sense. Virtually all research into PBD, however, presumes that the event history is a linear sequence of user actions. This paper challenges that notion by introducing Hierarchical Event Histories, a new approach which represents some of the end-user''s task structure directly in the event history. PBD systems can then take advantage of this structure to operate more correctly and in more situations. To assist programmers in generating structured histories, we also present Hieractors, a new model that provides a simple and clear syntax for describing arbitrary, high-level application behaviors.
Implementation of collaborative technologies as a learning process
Authors: Tatyana Bondarouk, Klaas Sikkel
Venue: Critical reflections on information systems: a systemic approach (2003)

Nowadays, more and more information and communication technologies (ICT) gain the characteristics of groupware as they strive to support different aspects of collaborative work. These types of ICT become progressively intertwined in the infrastructures of companies and therefore their implementation deserves as much attention as their design and development. However the literature keeps on providing examples of failures of groupware projects. In this paper we propose a novel theoretical perspective to understand implementation of such technologies based on learning theories. A technology implementation process is regarded as a learning process. The model describes two levels of the implementation process: the user level (individuals and groups) and the organisational level. At the group level it is based on five steps of collaborative learning within a group of users. At the organisational level it is related to the learning climate. By means of the longitudinal case study we have operationalized the constructs from the model towards concrete user-group and managerial activities that advance implementation of groupware. The discussion leads us to conjecture that a better organisational learning climate could promote successful implementation of groupware through group learning. Ultimately the insights derived from the model should lead to the tangible ways to foster the learning climate.
Hyperbolic conservation laws with space-dependent flux: I. Characteristics theory and Riemann problem
Authors: Peng Zhang, Ru-Xun Liu
Venue: Journal of Computational and Applied Mathematics (2003)

In the paper, a kind of one-dimensional scalar hyperbolic conservation laws with flux functions dependent on space variable is discussed and analyzed. A better understanding about the behavior of wave propagation of the kind problems is presented. Especially, some sufficient and necessary conditions that ensure the unique physically relevant solution to the Riemann problem are proposed. Because the numerical flux obtained from the Riemann's solver is theoretically correct and exact to the problem, it must also be of high resolution in its nature. For comparison, some convincing numerical examples from traffic flow problems are given at the end of the paper.
Photometric Image-Based Rendering for Virtual Lighting Image Synthesis
Authors: Yasuhiro Mukaigawa, Sadahiko Mihashi, Takeshi Shakunaga
Venue: Proceedings of the 2nd IEEE and ACM International Workshop on Augmented Reality (1999)

A concept named Photometric Image-Based Rendering (PIBR) is introduced for a seamless augmented reality. The PIBR is defined as Image-Based Rendering which covers appearance changes caused by the lighting condition changes, while Geometric Image-Based Rendering (GIBR) is defined as Image-Based Rendering which covers appearance changes caused by the view point changes. The PIBR can be applied to image synthesis to keep photometric consistency between virtual objects and real scenes in an arbitrary lighting condition. We analyze the conventional IBR algorithms, and formalize the PIBR in the whole IBR framework. A specific algorithm is also presented for realizing the PIBR. The photometric linearization makes a controllable framework for the PIBR, which consists of four processes; (1) separation of environmental illumination effects, (2) estimation of lighting directions, (3) separation of specular reflections and cast-shadows, and (4) linearization of self-shadows. After the photometric linearization of input images, we can synthesize any realistic images which include not only diffuse reflections but also self-shadows, cast-shadows and specular reflections. Experimental results show that realistic images can be successfully synthesized with keeping photometric consistency.
Software Metrics Model For Integrating Quality Control And Prediction
Authors: N. F. Schneidewind
Venue: Proceedings of the Eighth International Symposium on Software Reliability Engineering (1997)

A model is developed that is used to validate and apply metrics for quality control and quality prediction, with the objective of using metrics as early indicators of software quality problems. Metrics and quality factor data from the Space Shuttle flight software are used as an example. Our approach is to integrate quality control and prediction in a single model and to validate metrics with respect to a quality factor. Boolean discriminant functions (BDFs) were developed for use in the quality control and quality prediction process. BDFs provide good accuracy for classifying low quality software because they include additional information for discriminating quality: critical values. Critical values are threshold values of metrics that are used to either accept or reject modules when the modules are inspected during the quality control process. A series of nonparametric statistical methods is also used in the method presented. It is important to perform a marginal analysis when making a decision about how many metrics to use in the quality control and prediction process. We found that certain metrics are dominant in their effects on classifying quality and that additional metrics are not needed to accurately classify quality. This effect is called dominance. Related to the property of dominance is the property of concordance, which is the degree to which a set of metrics produces the same result in classifying software quality. A high value of concordance implies that additional metrics will not make a significant contribution to accurately classifying quality; hence, these metrics are redundant.
Preconditioned Eigensolvers: Practical Algorithms
Authors: Andrew V. Knyazev
Venue:  (1999)

We propose a systematic review of preconditioned iterative methods for symmetric eigenvalue problems, separating the choice of the preconditioner and the choice of the iterative scheme. We describe several known methods, concentrating on algorithms and with just brief references to existing theory. We discuss, in some details, the algorithm of the recently suggested by the author Optimal Block Conjugate Gradient Method. We present numerical results showing that the method converges linearly with the optimal convergence rate. Numerical comparison establishes that our method is much faster than the Block Steepest Ascent Method when the same preconditioner is used in both methods. We discuss peculiarities of locking for preconditioned iterative eigensolvers.