ppxscal/embedding_network huggingface dataset:
Collision Avoidance in Single-Channel Ad Hoc Networks Using Directional Antennas
Authors: Yu Wang, J. J. Garcia-Luna-Aceves
Venue: Proceedings of the 23rd International Conference on Distributed Computing Systems (2003)

Three collision-avoidance protocols are analyzed thatuse omni-directional packet reception together with omni-directionaltransmissions, directional transmissions, or acombination of both. A simple model is introduced to analyzethe performance of these collision avoidance protocolsin multi-hop networks with arbitrary topologies. Thenumerical results of this analysis show that collision avoidanceusing a narrow antenna beamwidth for the transmissionof all control and data packets achieves the highestthroughput among the three collision avoidance schemesconsidered. Simulation experiments of the popular IEEE802.11 MAC protocol and its variants based on directionaltransmissions and omni-directional packet reception validatethe results predicted in the analysis. The results furthershow that narrow-beamwidth transmissions can alsoreduce the average delay experienced by nodes. It is concludedthat the advantage of spatial reuse achieved bynarrow-beamwidth transmissions outweighs that of conservativecollision avoidance schemes featured by the omni-directionaltransmission of some control packets. This isdue to the fact that the latter requires far more stringent coordinationof nodes with their neighbors and hidden terminals,which can lead to much more channel resource wasteddue to nodes' excessive waiting time.
Analysis of a Software Reliability Growth Model with Logistic Testing-Effort Function
Authors: Chin-Yu Huang, Sy-Yen Kuo, Ing-Yi Chen
Venue: Proceedings of the Eighth International Symposium on Software Reliability Engineering (1997)

In this paper, we investigate a Software Reliability Growth Model (SRGM) based on the Non Homogeneous Poisson Process (NHPP) which incorporates a logistic testing-effort function. Software reliability growth models proposed in the literature incorporate the amount of testing-effort spent on software testing which can be described by an Exponential curve, a Rayleigh curve, or a Weibull curve. However, it may not be reasonable to represent the consumption curve for testing- effort only by an Exponential, a Rayleigh or a Weibull curve in various software development environments. Therefore, we will show that a logistic testing-effort function can be expressed as a software development/test effort curve and give a reasonable predictive capability for the real failure data. Parameters are estimated and experiments on three actual test/debug data sets are illustrated. The results show that the software reliability growth model with logistic testing-effort function can estimate the number of initial faults better than the model with Weibull-type consumption curve. In addition, the optimal release policy of this model based on cost- reliability criterion is discussed.
Novel Principles for Developing and Evaluating Distributed Safety-Critical Systems
Authors: Horst F. Wedde, Jon A. Lind
Venue: Proceedings of the The Fourth International Symposium on Autonomous Decentralized Systems (1999)

Safety-critical systems typically operate in unpredictable environments. Requirements for safety and reliability are in conflict with those for real-time responsiveness. Due to environmental needs there is no static trade-off between measures to accommodate the conflicting objectives. Instead, every feature or operating system service must be adaptive. MELODY was developed for supporting safety-critical applications under such constraints. This paper gives a brief survey of the different MELODY development phases by utilizing our heuristic design and evaluation methodology, Incremental Experimentation. A particular emphasis is laid on our novel adaptive concept of distributed task monitoring, plus it evaluation, regarding the total number of deadline failures as well as survivability.
Higher-Order Horn Clauses
Authors: Gopalan Nadathur, Dave Miller
Venue:  (1989)

A generalization of Horn clauses to a higher-order logic is described and examined as a basis for logic programming. In qualitative terms, these higher-order Horn clauses are obtained from the first-order ones by replacing first-order terms with simply typed $\lambda$-terms and by permitting quantification over all occurrences of function symbols and some occurrences of predicate symbols. Several proof-theoretic results concerning these extended clauses are presented. One result shows that although the substitutions for predicate variables can be quite complex in general, the substitutions necessary in the context of higher-order Horn clauses are tightly constrained. This observation is used to show that these higher-order formulas can specify computations in a fashion similar to first-order Horn clauses. A complete theorem proving procedure is also described for the extension. This procedure is obtained by interweaving higher-order unification with backchaining and goal reductions, and constitutes a higher-order generalization of SLD-resolution. These results have a practical realization in the higher-order logic programming language called $\lambda$Prolog.
A Method for Calibrating See-Through Head-Mounted Displays for AR
Authors: Erin McGarrity, Mihran Tuceryan
Venue: Proceedings of the 2nd IEEE and ACM International Workshop on Augmented Reality (1999)

In order to have a working AR system, the see-through system must be calibrated such that the internal models of objects match their physical counterparts. By match, we mean they should have the same position, orientation, and size information as well as any intrinsic parameters (such as focal lengths in the case of cameras) that their physical counterparts have. To this end, a procedure must be developed which estimates the parameters of these internal models. This calibration method must be both accurate and simple to use.This paper reports on our efforts to implement a calibration method for a see-through head-mounted display. We use a dynamic system in which a user interactively modifies the camera parameters until the image of a calibration object matches the image of a corresponding physical object. The calibration method is dynamic in the sense that we do not require the user's head to be immobilized.
Models of blocking probability in all-optical networks with and without wavelength changers
Authors: R. A. Barry, P. A. Humblet
Venue: Proceedings of the Fourteenth Annual Joint Conference of the IEEE Computer and Communication Societies (Vol. 2)-Volume - Volume 2 (1995)

We introduce a traffic model for circuit switched all-optical networks (AONs) which we then use to calculate the blocking probability along a path for networks with and without wavelength changers. We investigate the effects of path length, switch size, and interference length (the expected number of hops shared by two sessions which share at least one hop) on blocking probability and the ability of wavelength changers to improve performance. Our model correctly predicts unobvious qualitative behavior demonstrated in simulations by other authors.
Distributed and Persistent Mobile Agents for Heterogeneous Personal Communications Systems
Authors: Peter Staqski, Arkady Zaslavsky
Venue: Proceedings of the 6th International Conference on Computer Communications and Networks (1997)

Problems of environment heterogeneity and interoperability between different mobile computing platforms are among the most urgent to address by the research community. This paper proposes an environment, which supports migration of mobile code developed using heterogeneous languages. Current developments in the area of mobile code and distributed mobile computing systems are discussed and placed within the context of the proposed system. The architecture behind the proposed Portable Environment Small Operating System (PESOS) provides an open platform for distributed persistent personal agents written using a variety of languages. Additionally, PESOS introduces and discusses the concept of a uniform migration wrapper consisting of portable file systems (PFS) within which applications and data are embedded.
Distributed Object Models, Mobile Computing And Electronic Commerce
Authors: V. K. Murthy, E. V. Krishnamurthy, A. Pham
Venue: Proceedings of the 1998 International Conference on Parallel Processing Workshops (1998)

This paper presents an overview of the Models,Programming Paradigms and Software Tools needed for anintegrated network (wired and wireless) computingenvironment that can support electronic Commerce. Inparticular, we consider the role of various interactivedistributed computing models (client server-CS, code ondemand -COD, remote evaluation- REV, and mobile agents- MA, and three-tier system- TTS), different logical modesof programming (Imperative, declarative, subjunctive andabductive), transaction and workflow models (that relaxatomicity, consistency, isolation, duarbility andserializability properties), new protocols and software tools(PJava/JDBC/ CORBA products) that are needed.
Slicing Concurrent Java Programs
Authors: Jianjun Zhao
Venue: Proceedings of the 7th International Workshop on Program Comprehension (1999)

Although many slicing algorithms have been proposed for object-oriented programs, no slicing algorithm has been proposed which can be used to handle the problem of slicing concurrent Java programs correctly. In this paper, we propose a slicing algorithm for concurrent Java programs. To slice concurrent Java programs, we present a dependence-based representation called multithreaded dependence graph, which extends previous dependence graphs, to represent concurrent Java programs. We also show how static slices of a concurrent Java program can be computed efficiently based on its multithreaded dependence graph.
The measured performance of a fast local IPC
Authors: J. S. Shapiro, D. J. Farber, J. M. Smith
Venue: Proceedings of the 5th International Workshop on Object Orientation in Operating Systems (IWOOOS '96) (1996)

Protected application decomposition is limited by the performance of the local interprocess procedure call implementation. In this paper we measure the performance of a new IPC implementation, and show that the cost of IPC can be reduced to the cost of raw memory copy plus a small overhead. Even on machines with poor context switching performance, our implementation compares favorably with bcopy() for surprisingly small payloads.
Model of the Intellectual Analysis of Dynamic Processes with the Use of an Indistinct-Temporal Conclusion on the Simulating Columns
Authors: Sergey M. Kovalev
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

The problems of modeling the poorly formalized dynamic processes (DP) in intellectual systems on the basis of indistinctly-temporal graph models is here in considered. In order to present the knowledge in a system a general of temporal logic on indistinct events is used. A method ofindistinct-inference in a dynamic knowledge base (BK), based on a search of isomorphic superpositions of the indistinct graphs , is offered. 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
Challenges in URL Switching for Implementing Globally Distributed Web Sites
Authors: Zornitza Genova, Kenneth J. Christensen
Venue: Proceedings of the 2000 International Workshop on Parallel Processing (2000)

URL, or layer-5, switches can be used to implement locally and globally distributed web sites. URL switches must be able to exploit knowledge of server load and content (e.g., of reverse caches). Implementing globally distributed web sites offers difficulties not present in local server clusters due to bandwidth and delay constraints in the Internet. With delayed load information, server selection methods based on choosing the least-loaded server will result in oscillations in network and server load. In this paper, methods that make effective use of delayed load information are described and evaluated. The new Pick-KX method is developed and shown to be better than existing methods. Load information is adjusted with probabilistic information using Bloom filter summaries of site content. A combined load and content metric is suggested for use for selecting the best server in a globally distributed site.
Quantitative Evaluation of the Register Stack Engine and Optimizations for Future Itanium Processors
Authors: R. David Weldon, Steven S. Chang, Hong Wang, Gerolf Hoflehner, Perry H. Wang, Dan Lavery, John P. Shen
Venue: Proceedings of the Sixth Annual Workshop on Interaction between Compilers and Computer Architectures (2002)

This paper examines the efficiency of the register stack engine (RSE) in the canonical Itanium architecture, and introduces novel optimization techniques to enhance the RSE performance. To minimize spills and fills of the physical register file, optimizations are applied to reduce internal fragmentation in statically allocated register stack frames. Through the use of dynamic register usage (DRU) and dead register value information (DVI), the processor can dynamically guide allocation and deallocation of register frames. Consequently, a speculatively allocated register frame with a dynamically determined frame size can be much smaller than the statically determined frame size, thus achieving minimum spills and fills. Using the register stack engine (RSE) in the canonical Itanium architecture as the baseline reference, we thoroughly study and gauge the tradeoffs of the RSE and the proposed optimizations using a set of SPEC CPU2000 benchmarks built with different compiler optimizations. A combination of frame allocation policies using the most frequent frame size and deallocation policies using dead register information proves to be highly effective. On average, a 71% reduction in aggregate spills and fills can be achieved over the baseline reference.
Routing in Ad Hoc Networks Using a Spine
Authors: Bevan Das, Raghupathy Sivakumar, Vaduvur Bharghavan
Venue: Proceedings of the 6th International Conference on Computer Communications and Networks (1997)

We present a two-level hierarchical routing architecture for ad hoc networks. Within each lower level cluster, we describe a self-organizing, dynamic {\em spine} structure to (a) propagate topology changes, (b) compute updated routes in the background, and (c) provide backup routes in case of transient failures of the primary routes. We analyze and bound the worst case of movements between upper level clusters to show that this hierarchical architecture scales well with network size.
A distributed algorithm of delay bounded multicast routing for multimedia applications
Authors: Xiaohua Jia, N. Pissinou, K. Makki
Venue: Proceedings of the 6th International Conference on Computer Communications and Networks (1997)

The aim of multicast routing is to find a tree which is rooted from the source node and contains all the multicast destinations. A delay bounded routing tree, is a tree where the accumulated delay from the source node to any destination along the tree shall not exceed a pre-specified bound. This paper presents a distributed heuristic algorithm which generates routing trees with sub-optimal network cost under the delay bound constraint. The proposed algorithm is fully distributed, efficient in terms of the number of messages required, and flexible in multicast membership changes. A large amount of simulations have been done to show that the network cost of the routing trees generated by our algorithm is better than the major existing algorithms.
Database Modularization Design for the Construction of Flexible Information Systems
Authors: João Eduardo Ferreira, Gisele Busichia
Venue: Proceedings of the 1999 International Symposium on Database Engineering & Applications (1999)

Medium-sized and large private companies and public institutions usually have several operational units that enjoy increasing scope to define their own rules for the development of their activities, procedures and modus operandi. From the point of view of the development of specific software to support the activities of these organizations, this freedom means that systems must be sufficiently flexible not only to allow them to be configured to fulfill each unit's needs and specific modes of operation but also to meet the needs of interaction among them through information exchange. In the case of an application consisting of several subsystems, the existence of a data repository common to all these subsystems means that, although parts of the database are accessed by only one subsystem, the data are stored in a monolithic form, translating into a loss of autonomy of the subsystems involved. The objective of this work is to propose guidelines for the modularization of databases, for both corporate data center schemas and specific schemas for independent units. This modularization not only supports the solutions to the interoperability but also enables Information Systems based on the data models in question to be really flexible.
Multiple-Valued Logic as a Programming Language
Authors: R. J. Bignall, M. Spinks
Venue: Proceedings of the 27th International Symposium on Multiple-Valued Logic (1997)

A method for specifying the computable functions using multiple-valued logics is described. The logics in question provide a uniform environment both for specifying computable functions on the natural numbers and for proving theorems about such specifications. They arise via a generalisation to the countable-valued case of techniques that may be used in specifying multiple-valued switching circuits by finite-valued predicate logics. In this paper a concrete instance of such a language, based on a modification of dual skew Boolean logic, is constructed. The result may be viewed as a a simple functional/logic programming language that is, in principle, executable.
An Event Driven Software Architecture for Enterprise-Wide Data Source Integration
Authors: Perfecto Mariño, Cesar Sigüenza, Juan Nogueira, Francisco Poza, Miguel Dominguez
Venue: Proceedings of the The International Conference on Information Technology: Coding and Computing (ITCC'00) (2000)

This is a work in progress paper where authors are involved in a Telco corporation reengineering project of a half terabyte Data Warehouse (DW). Firstly, the DW context is introduced, focusing in three related and critical issues: the data source integration, component reuse and performance bottlenecks. Then we discuss the actual implicit architecture found in the runtime system, identifying the problems. Finally, the proposed architecture is presented. It has two views: a static made with filters and pipes, and a dynamic based on an event driven scheduler, as opposed to a fixed time one. In the runtime scenario, the scheduler reads the pipe configurations from the metadata repository, and then executes on the fly the planed filters, transforming data into business information.
The Knowledge Entrepreneur
Authors: Colin Coulson-Thomas
Venue:  (2003)

:This unique book puts a whole new spin on knowledge management. Rather than re-stating the importance of the knowledge economy, or detailing methods of knowledge management or acquisition, it explores how businesses can exploit their knowledge and information, focusing on the entrepreneurial opportunities that intellectual capital provides. Topics covered include: knowledge overload, creating enterprise cultures, monitoring trends, identifying opportunities, and how to build a knowledge-based venture. The book also provides chapter-by-chapter practical checklists for assessing the general potential and particular opportunities that information and knowledge offer. It includes a free CD-ROM which will contains checklists, forms and templates. 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
The Warwick Framework: A Container Architecture for Aggregating Sets of Metadata
Authors: Carl Lagoze, Clifford A. Lynch, Ron Daniel,  Jr.
Venue:  (1996)

We describe a result of the June 1996 Warwick Metadata II Workshop. This Warwick Framework is a container architecture for aggregating logically, and perhaps physically, distinct packages of metadata. This architecture allows separate administration and access to metadata packages, provides for varying syntax in each package in conformance with semantic requirements, and it promotes interoperability and extensibility by allowing tools and agents to selectively access and manipulate individual packages and ignore others. At the conclusion of the paper we propose implementations of the Framework in HTML, MIME, SGML, and distributed objects.
A neural network model of the cortico-hippocampal interplay: contexts and generalization
Authors: A. Bibbig, T. Wennekers, G. Palm
Venue: Proceedings of the First International Symposium on Intelligence in Neural and Biological Systems (INBS'95) (1995)

We present computer simulations of a neural network comprising two sensory pathways, each built of preprocessing and associative memory modules perhaps corresponding to a primary and higher sensory area, and a hippocampal area that serves as an integration or fusion zone during learning and retrieval of polymodal information. The network is able to store unimodal details about a complex environment in local assemblies restricted to the corresponding associative memory, whereas a representation of the simultaneous occurrences of several stimuli is constituted and stored in a self-organizing manner in the hippocampal area. This can be viewed as storage of a "particular context". If many stimulus constellations are presented to the network during learning, it may over-learn, that is, the hippocampal area can no longer distinguish particular situations, but instead represents more general contexts or categories, a given environmental situation may belong to. Feedback from the hippocampal region to association areas can restore particular memories; it can still act as a threshold control gate raising sensitivity in the appropriate cortex regions when it is overloaded.
Analysis of Zero Clusters in Multivariate Polynomial Systems
Authors: Hans J. Stetter
Venue:  (1996)

We consider a cluster of m zeros of a multivariate polynomial system which we interpret as a perturbation of a system with an m-fold zero. By algebraic techniques, we find a first order correct representation of the primary ideal of the cluster zeros from which we obtain approximations for the individual zeros in the cluster.
Student satisfaction with groupwork in undergraduate computer science: do things get better?
Authors: Helen Drury, Judy Kay, Warren Losberg
Venue: Proceedings of the fifth Australasian conference on Computing education - Volume 20 (2003)

Groupwork has a large and important role in computer science courses. Moreover, groupwork skills are among the most important generic attributes students should develop during their studies as preparation for the world of work (Candy, Crebert and O'Leary, 1994, Dearing, 1997). At the same time, all who have been involved in teaching that involves groupwork will be aware that it brings challenges. It is important to support student learning of group skills, to develop instruments for evaluating this aspect of teaching and to measure student development in groupwork skill as well as student perceptions of their groupwork experiences.This paper reports on a cross sectional evaluation of student perceptions of groupwork. It is based upon both group interviews and a questionnaire. An important contribution of this work is the questionnaire which could be readily used in quality assurance elsewhere. Another contribution derives from the results of our study. They give useful insight into student perceptions across cross sectional cohorts and according to academic ability. We also report on ways that this study has helped us define strategies to improve the development of student skills in groupwork.