ppxscal/embedding_network huggingface dataset:
ON THE EXPRESSIVE POWER OF DATALOG: TOOLS AND A CASE STUDY
Authors: Phokion G. Kolaitis
Venue:  (1990)

We study here the language Datalog(not =), which is the query language obtained from Datalog by allowing equalities and inequalities in the bodies of the rules. We view Datalog(not =) as a fragment of an infinitary logic L^omega and show that L^omega can be characterized in terms of certain two-person pebble games. This characterization provides us with tools for investigating the expressive power of Datalog(not =). As a case study, we classify the expressibility of *fixed subgraph homeomorphism* queries on directed graphs. Fortune et al. classified the computational complexity of these queries by establishing two dichotomies, which are proper only if P not = NP. Without using any complexity-theoretic assumptions, we show here that the two dichotomies are indeed proper in terms of expressibility in Datalog(not =).
Special finite elements for high frequency elastodynamic problems: first numerical experiments
Authors: O. Laghrouche, P. Bettess, D. Le Houédec
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

The horizontal and vertical displacements of the soil medium in harmonic steady state response are, first, written as a summation of the compressional, shear and Rayleigh waves contributions. Then, each displacement due to each wave is approximated by systems of plane waves propagating in different directions. The aim is to develop finite elements capable of containing many wavelengths per nodal spacing and therefore to simulate problems at high frequency without refining the mesh to satisfy the traditional requirement of around ten nodal points per wavelength.
The automatic hierarchical decomposition of images into sub-images for use in image recognition and classification
Authors: Paul S Williams
Venue:  (1999)

This thesis addresses the problem of image recognition and classification with the aim of developing a generic framework applicable to a wide range of image types and recognition problems. The approach is to use an algorithm, or set of algorithms, to automatically infer and extract structure which possibly corresponds to meaningful objects. Extracted structure is examined for further structure, hence providing a hierarchical process. The investigated framework, referred to as the UpWrite, consists in its ideal form of localisation, amalgamation and representation phases. Initially, an image is examined locally to extract features which are used as low level primitives. These are analysed using one or several algorithms and amalgamated into higher level entities based on structure. The entities, possibly corresponding to meaningful objects, are represented in a chosen standard form. They may be classified or analysed locally in this new form for amalgamation and representation at an increasingly higher level of abstraction. Hence, the process is hierarchical, transforming numerous low level primitives into increasingly higher level objects. It is also intended to be generic, making few assumptions without image specific parameters, and while being automated, also allow a human to determine why a particular result was produced. The application of the framework is demonstrated on three restricted decomposition problems. Anomaly detection: Grey scale images containing a few isolated defects or anomalous regions on an otherwise homogeneous background are investigated. With the focus on painted steel images containing subtle surface defects, the background is successfully identified and represented. The isolated anomalies are subsequently investigated by locally analysing the corresponding feature vectors. Extracted structure is sufficient to classify images by defect type. Grey scale newspaper segmentation: The second restricted problem aims to decompose grey scale newspaper images into regions corresponding to background, pictures and text. Using the same feature extraction framework applied to anomaly detection, and identifying multiple objects rather than one single homogeneous background, the image is segmented. Results are very good, although subjective, across all images examined. The method compares favourably to segmentation using Gabor filters based on region prototypes. Coloured natural scenes: Finally, the less restricted problem of segmenting coloured natural scenes is examined. Using the same type of low level primitives with the inclusion of a novel colour representation, a region growing segmentation algorithm amalgamates local features into spatially disjoint regions. The representations of these regions are used as predictors to amalgamate objects consisting of disjoint segments. Classification of 1000 images from 11 categories yields
A Calculus for End-to-end Statistical Service Guarantees
Authors: Jorg Liebeherr, Stephen Patek, Almut Burchard
Venue:  (2001)

The deterministic network calculus offers an elegant framework for determining delays and backlog in a network with deterministic service guarantees to individual traffic flows. A drawback of the deterministic network calculus is that it only provides worst-case bounds. Here we present a network calculus for statistical service guarantees, which can exploit the statistical multiplexing gain of sources. We introduce the notion of an effective service curve as a probabilistic bound on the service received by an individual flow, and construct an effective service curve for a network where capacities are provisioned exclusively to aggregates of flows. Numerical examples demonstrate that the calculus is able to extract a significant amount of multiplexing gain in networks with a large number of flows.
Building Fundamentally Extensible Application-Specific Operating Systems in SPACE [Probert, Bruno]
Authors: Dave Probert, John Bruno
Venue:  (1995)

We refine and extend previous work towards a new approach to implementing operating systems. This approach, called SPACE, uses processors, address spaces, and a generalized exception mechanism as the basic abstractions rather than processes, virtual memory, and interprocess communication. The result is that the facilities provided by the hardware architecture are exposed, and can be directly used by applications to achieve higher performance and more diverse functionality than is possible with conventional operating system abstractions. In SPACE the conventional abstractions can coexist with new application-specific abstractions, due to the fundamental extensibility of the SPACE primitives. Applications can implement their own versions of system services to satisfy critical functional and performance requirements while still benefiting from standard system services. In this paper we present a generalization of our earlier framework which allows the SPACE primitives themselves to be extended, and illustrate SPACE by describing an implementation on the SPARC architecture. We then give examples of implementing mechanisms in SPACE.
Decision tree classifiers for computer intrusion detection
Authors: Xiangyang Li, Nong Ye
Venue: Real-time system security (2003)

Intrusion detection is required to protect the security of computer network systems by detecting intrusive activities occurring in computer network systems. In this paper, we present decision tree techniques that are used to automatically learn intrusion signatures and classify activities in computer network systems as normal or intrusive for intrusion detection. We show the design of decision tree classifiers for intrusion detection, using different features of raw activity data in computer network systems and different sizes of observation windows. The performance of decision tree classifiers is discussed. We also present the impact of noises in data on the detection performance of the decision tree classifiers. Computer audit data from the Basic Security Module of the Solaris operating system are used to train and test the decision tree classifiers.
An Empirical Study of Maintenance Activities in an Object OrientedSystem
Authors: Wei Li, Sallie M. Henry
Venue:  (1993)

Decades of research on maintenance activities in the procedural paradigm has produced several conclusions. Among these conclusions are recommendations that a reduction in maintenance cost could be achieved by a more controlled design process, by more rigorous testing of potential problem areas earlier in the life cycle. With the increasing emphasis on the object oriented paradigm, the authors performed an empirical study of the maintenance patterns in a commercial object oriented system. Although this is a preliminary study, intuition is presented as insight into the object oriented maintenance activities.
A New Model of Security for Distributed Systems
Authors: William A. Wulf, Chenxi Wang, Darrell Kienzle
Venue:  (1995)

With the rapid growth of the information age, electronic activities of many kinds are becoming more common. The need for protection and security in this environment has never been greater. The conventional approach to security has been to enforce a system-wide policy, but this approach will not work for large distributed systems where entirely new security issues and concerns are emerging.We argue that a new model is needed that shifts the emphasis from "system as enforcer" to user-definable policies in which the cost scales with the degree of security required. Users ought to be able to select the level of security they need and pay only the overhead necessary to achieve it. Moreover, ultimately, they must be responsible for their own security. This research is being carried out in the context of the Legion project. We start by describing the objectives and philosophy of the overall project and then present our conceptual model and tentative implementation plan. A set of technical challenges is also addressed.
Efficient Implementation of Synchronous Communication Over Asynchronous Networks
Authors: Manhoi Choy, Ambuj K. Singh
Venue:  (1993)

The implementation of synchronous communication primitives over asynchronous message-passing networks is investigated. Efficient algorithms are presented for the committee coordination problem and its more dynamic version called the first-order interaction problem. A new notion of strong fairness called $1$-$sf$ and algorithms achieving it are described. It is further shown that any stronger notion of fairness cannot be implemented.
HIGH SPEED DISK I/O FOR PARALLEL COMPUTERS
Authors: Daniel Edelson, Darrell D. E. Long
Venue:  (1990)

The purpose of this research has been to determine how disk subsystems can support high speed I/O for large scale multiprocessors. A literature survey has identified many of the most important techniques for substantially improving disk performance. In addition we have designed (and analyzed through simulation) a software architecture that supports very high data rates. Our findings are summarized in this report.
A Structural and Evolutionary Approach to Change Management
Authors: Thierry Rakotobe-Joel, Ian P. McCarthy, David Tranfield
Venue: Computational Mathematical Organization Theory (2002)

Organizational change management is concerned with realizing strategies using models, methods and prescriptions that seek to guide the three key elements of strategic management process: strategic analysis (what is our current configuration?), strategic choice (what is our desired configuration?) and strategic implementation (how to realize the desired configuration?). To address these strategic management issues, this paper presents an evolutionary and structural approach that uses a classification technique (cladistics) and a method from algebraic topology (q-analysis) to identify and understand different organizational configurations, along with the relationships and connectivity (change route) between a current and desired configuration. A simple example data set is used to introduce and describe the cladistic and q-analysis methods. This is followed by an application of the technique to a data set from the automotive assembly industry.
History-based Access Control for Mobile Code
Authors: Anurag Acharya, Guy Edjlali
Venue:  (1997)

In this paper, we present a {\em history-based} access-control mechanism that is suitable for mediating accesses from mobile code. Combined with a suitable identity-based mechanism (eg, digital signatures), it significantly expands the set of programs that can be executed without compromising security or ease of use. We present {\em Deeds} a history-based access control mechanism for Java. Apart from history-based nature, the other important feature of Deeds is its capability to install and compose multiple user-specified policies. Access control policies in Deeds are written in Java, and can be updated while the programs whose accesses are being mediated is still in execution.
Verification of Fault-Tolerance and Real-Time
Authors: Z. Liu, M. Joseph
Venue:  (1996)

A transformational method is given for specifying and verifying fault-tolerant real-time programs. Such a program needs to be provably correct according to its both functional and real-time requirements, despite the presence of possible system failures. The paper demonstrates that a suitably expressive logic for real-time systems allows to naturally model the state changes by system failures and determine their effect on the functional and real-time properties of executions.
Tight Lower Bounds for Probabilistic Solitude Verification on Anomynous Rings
Authors: Karl Abrahamson, Andrew Adler, Lisa Higham, David G. Kirkpatrick
Venue:  (1990)

Tight lower bounds on the expected bit complexity of the Solitude Verification problem on anonymous asynchronous unidirectional rings are established that match the upper bounds demonstrated in a companion paper [5]. In the algorithms of [5], a variety of techniques are applied; In contrast, we find that a single technique, applied carefully, suffices for all of the lower bounds. The bounds demonstrate that, for this problem, the expected bit complexity depends subtly on the processors'' knowledge of the size of the ring, and on the type of algorithm (Las Vegas or Monte Carlo / distributive or nondistributive termination).
Keeping your eyes on the prize: using inquiry to increase the benefits of institutional portals
Authors: Stephen C. Ehrmann
Venue: Designing portals: opportunities and challenges (2003)

This chapter describes eight potential educational uses of institutional portals (e.g., helping instruction become more spontaneous and adaptive; supporting learning communities; reducing cost of service delivery). It then describes a long-term program of data collection that can improve the educational effectiveness of portals, and control the costs and stresses of portal operation. Studies include: a. baseline data (how well are those goals being met without a portal?), b. debugging studies (what factors are tending to block portal effectiveness?), c. cost studies (what aspects of portal development, operation and use are so costly, time-consuming or stressful that they threaten system success?) and d. outcomes assessment (is portal use contributing to outcome improvement?). The non-profit Flashlight Program has developed a number of evaluation tool kits that can be helpful in doing studies of these kinds.
Simple decision support system based on fuzzy repertory table
Authors: J. J. Castro-Schez, L. Jimenez, J. Moreno, L. Rodriguez
Venue: Enterprise information systems IV (2003)

This paper shows how fuzzy repertory table technique (Castro et al., 2001) can be used as a simple decision support system for helping to a manager of a company when he is faced with a choice in which the options are clear (for instance, the choice of a suppliers from among all existing suppliers, or the choice of sell one product from among all existing posiblities). The manager must analyse each option making use of his knowledge, with the aim to highlight its characteristic qualities which are admirable in themselves or useful for our purpose and also its defective qualities. Next, the manager choices the more advantageous opcion according to this information. When the possible options are clear, the analysis implies make comparisons among the several options. Thus, the manager find out the characteristic and defective qualities associated to each option. With the suggested method in this paper, we identity the relevant information (characteristic and defective) associated to each option and recommend one option according to this information.
Teaching Software Engineering in a Compiler Project Course
Authors: William G. Griswold
Venue:  (2000)

A compiler course with a term-long project is a staple of many undergraduate computer science curricula and often a cornerstone a program''s applied-engineering component. Software engineering expertise can help a student complete such a course, yet that expertise is often lacking. This problem can be addressed without detracting from the core class material by integrating a few simple software engineering practices into the course. A domain-specific, risk-driven approach minimizes overhead and keeps the compiler material in focus, while treating the project as a ``real world'''' enterprise reinforces key engineering lessons. The method might be called ``syntax-directed software engineering'''', being driven by a specification centered around a BNF-style grammar. Engineering lessons are reinforced with general engineering principles and contextualization of the subject matter. The approach can be taught without substantial software engineering background. The approach of domain-specific risk-driven software engineering can be applied in courses such as operating systems by redesigning the practices around the its domain.
Determining the idle time of a tiling
Authors: Karin Hogstedt, Larry Carter, Jeanne Ferrante
Venue:  (1999)

This paper investigates the idle time associated with a parallel computation, that is, the time that processors are idle because they are either waiting for data from other processors or waiting to synchronize with other processors. We study doubly-nested loops corresponding to parallelogram- or trapezoidal-shaped iteration spaces that have been parallelized by the well-known tiling transformation. We introduce the notion of rise r, which relates the shape of the iteration space to that of the tiles. For parallelogram-shaped iteration spaces, we show that when r -2, the idle time is linear in P, the number of processors, but when r -1, it is quadratic in P. In the context of hierarchical tiling, where multiple levels of tiling are used, a good choice of rise can lead to less idle time and better performance. While idle time is not the only cost that should be considered in evaluating a tiling strategy, current architectural trends (of deeper memory hierarchies and multiple levels of parallelism) suggest it has increasing importance.
Application of Fuzzy Logic and Neural Networks to the Control of a FlameProcess
Authors: Wenjing Tao, Hans Burkhardt
Venue:  (1994)

This paper describes a vision-guided closed loop control for stationary luminous flames using fuzzy logic and neural networks. The issues involved in feature extracting of flame images are addressed. The neural constructing of the fuzzy rules as well as two training methods i.e., supervised training and reinforcement training, are described. The experimental results by applying this controller are shown.
Implementing a Normative Theory of Communication in a Framework for Default Reasoning
Authors: Csinger Andrew
Venue:  (1991)

This thesis presents a framework for inter-agent communication, represented and partially implemented with default reasoning. I focus on the limited goal of determining the meaning for a Hearer-agent of an utterance $\omega$ by a Speaker-agent, in terms of the beliefs of the interlocutors. This meaning is generally more than just the explicit propositional contents of $\omega$, and more than just the Speaker''s goal to convey her belief that $\omega$. \nOne way of determining this meaning is to let the Hearer take stock of the implicit components of the Speaker''s utterances. Among the implicit components of the meaning of $\omega$, I show in particular how to derive certain of its presuppositions with a set of default schemata using a framework for default reasoning. \nMore information can be extracted from the communications channel between interlocutors by adopting a normative model of inter-agent communication, and using this model to explain or ''make sense'' of the Speaker''s utterances. I construct such a model expressed in terms of a set of default principles of communication using the same framework for default reasoning. \nThe task of deriving the meaning of an utterance is similar to the job required of a user-interface, where the user is the Speaker-agent, and the interface itself is the Hearer-agent. The goal of a user-interface as Hearer is to make maximal use of the data moving along the communications channel between user and application. \nThe result is an integrated theory of normative, inter-agent communications expressed within an ontologically and logically minimal framework. This work demonstrates the development and application of a methodology for the use of default reasoning. The implementation of the theory is also presented, along with a discussion of its applicability to practical user-interfacing. A view emerges of user-modelling as a component of a user-interface. 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
A Technology-Scalable Architecture for Fast Clocks and High ILP
Authors: Karthikeyan Sankaralingam, Ramadass Nagarajan, Steven W. Keckler, Doug Burger
Venue:  (2001)

CMOS technology scaling poses challenges in designing dynamically scheduled cores that can sustain both high instruction-level parallelism and aggressive clock frequencies. In this paper, we present a new architecture that maps compiler-scheduled blocks onto a two-dimensional grid of ALUs. For the mapped window of execution, instructions execute in a dataflow-like manner, with each ALU forwarding its result along short wires to the consumers of the result. We describe our studies of program behavior and a preliminary evaluation that show that this architecture has the potential for both high clock speeds and high ILP, and may offer the best of both the VLIW and dynamic superscalar architectures.
Evolutionary Trees can be Learned in Polynomial Time in the Two-State General Markov Model
Authors: Mary Cryan, Leslie A Goldberg, Paul W. Goldberg
Venue:  (1998)

The j-State General Markov Model of evolution (due to Steel) is a stochastic model concerned with the evolution of strings over an alphabet of size j. In particular, the Two-State General Markov Model of evolution generalises the well-known Cavender-Farris-Neyman model of evolution by removing the symmetry restriction (which requires that the probability that a `0'' turns into a `1'' along an edge is the same as the probability that a `1'' turns into a `0'' along the edge). Farach and Kannan showed how to PAC-learn Markov Evolutionary Trees in the Cavender-Farris-Neyman model provided that the target tree satisfies the additional restriction that all pairs of leaves have a sufficiently high probability of being the same. We show how to remove both restrictions and thereby obtain the first polynomial-time PAC-learning algorithm (in the sense of Kearns et al.) for the general class of Two-State Markov Evolutionary Trees.
Statecharts in Use: Structured Analysis and Object-Orientation
Authors: B. P. Douglass, D. Harel, M. Trakhtenbrot
Venue:  (1997)

We describe how statecharts are used to model the behavior of complex reactive systems. The paper is divided into two parts, according to the two main ways that have been suggested for modeling the structure of such systems: structured analysis (SA) and object-orientation (OO). It uses a cardiac pacemaker example for illustration. (This paper available in hard-copy only.)