ppxscal/embedding_network huggingface dataset:
A graphical environment for ontology development
Authors: Luigi Ceccaroni, Elisa Kendall
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

This paper presents current research on a semantically rich, graphical representation of ontologies and its utility for collaborative construction based on requirements outlined by the Agentcities initiative. A new tool, called the Visual Ontology Modeler, is described and evaluated in the context of Agentcities. Its distinguishing qualities include: ease of use, multi-user configuration management, integrated consistency and completeness checking, automated export of DAML+OIL code. The application domain is an open, dynamic test-bed for agent deployment; the ontologies are encoded in DAML+OIL and explicitly designed to be shared by several agent-based services within this environment.
On the Placement of Web Server Replicas
Authors: Lili Qiu, N. V Padmanabhan, M. G Voelker
Venue:  (2000)

Recently there has been an increasing deployment of content distribution networks (CDNs) that offer hosting services to Web content providers. CDNs deploy a set of servers distributed throughout the Internet and replicate provider content across these servers for better performance and availability than centralized provider servers. Existing work on CDNs has primarily focused on techniques for efficiently redirecting user requests to appropriate CDN servers to reduce request latency an d balance load. However, little attention has been given to the development of placement strategies for Web server replicas to further improve CDN performance. In this paper, we explore the problem of Web server replica placement in detail. We develop several placement algorithms that use workload information, such as client latency and request rates, to make informed placement decisions. We then evaluate the placement algorithms using both synthetic and real network topologies, and real Web server traces, and show that the placement of Web replicas is crucial to CDN performance. We also address a number of practical issues when using these algorithms, such as their sensitivity to imperfect knowledge about client workload and network topology, the stability of the input data, methods for obtaining the input, and the scalability of the algorithms.
Teledesic network and space infrastructure architecture and design features
Authors: J. R. Stuart
Venue: Proceedings of the 2nd IEEE International Conference on Engineering of Complex Computer Systems (1996)

Teledesic represents a revolutionary new architectural paradigm for distributed space systems design, production and operations. This paper describes the unique features of the Teledesic space infrastructure architecture, design, enabling technologies, production, deployment and operations that result from the demanding requirements of the Teledesic broadband services and global network design. The paper's introduction discusses the wireless information revolution and the current "Little" and "Big" communications LEOs. The current technological and economic trends that drive us inevitably to higher frequency bands and much larger constellations (/spl ges/1000 satellites) are briefly addressed.
A Comparison of Search Term Weighting: Term Relevance vs. Inverse Document Frequency
Authors: Harry Wu, Gerard Salton
Venue:  (1981)

The term relevance weighting method has been shown to produce optimal information retrieval queries under well-defined conditions. The parameters needed to generate the term relevance factors cannot unfortunately be estimated accurately in practice; furthermore, in realistic test situations, it appears difficult to obtain improved retrieval results using the term relevance weights over much simpler term weighting systems such as, for example, the inverse document frequency weights. It is shown in this study that the inverse document frequency weights and the term relevance weights are closely related over a wide range of the frequency spectrum. Methods are introduced for estimating the term relevance weights, and experimental results are given comparing the inverse document frequency with the estimated term relevance weights.
Representation Theorems and Theorem Proving in Non-Classical Logics
Authors: Viorica Sofronie-Stokkermans
Venue: Proceedings of the Twenty Ninth IEEE International Symposium on Multiple-Valued Logic (1999)

In this paper we present a method for automated theorem proving in non-classical logics having as algebraic models bounded distributive lattices with certain types of operators. The idea is to use a Priestley-style representation for distributive lattices with operators in order to define a class of Kripke-style models with respect to which the logic is sound and complete. If this class of Kripke-style models is elementary, it can then be used for a translation to clause form; satisfiability of the resulting clauses can be checked by resolution. We illustrate the ideas by several examples.
Modeling Parallel Computers as Memory Hierarchies (Extended Abstract)
Authors: Bowen Alpern, Larry Carter, Jeanne Ferrante
Venue:  (1993)

A generic model that captures the features of diverse computer architectures by approximate parameter choice would facilitate the development of portable programs. A successful generic model must be able to adequately reflect the costs of data movement in real computers. The Parallel Memory Hierarchy (PMH) model of computation uses a single mechanism to model the costs of both interprocessor communication and memory hierarchy traffic. A computer is modelled as a tree of memory modules with processors at the leaves. All data movement takes the form of block transfers between children and their parents. This paper assesses the strengths and weaknesses of the PMH model as a generic model. Such common features as communication cost given in terms of latency and bandwidth, as well as contention on a heavily loaded bus, are easily represented. Specific models for the CM-5, the KSR1, and a 2-dimensional mesh are derived and analyzed.
Flexible Multimedia System Architecture with Adaptive QoS Guarantee Functions
Authors: Koji Hashimoto, Yoshitaka Shibata, Noio Shiratori
Venue: Proceedings of the Seventh International Conference on Parallel and Distributed Systems (2000)

We propose a flexible multimedia system (FMS), which is based on agent-oriented architecture. The system is able to organize required functions itself, provide both realtime and stored multimedia information services simultaneously to users even though various user's multimedia environment and the resource utility of computers or networks has been dynamically changed. Distributed multimedia system not only integrates various multimedia information distributed over computer networks and but also provides it to users in accordance with the user's requirements during realtime multimedia communication must guarantee the user requested quality of services (QoS) even though the computer and network resources change statically or dynamically. This paper describes about the FMS architecture for multimedia teleconference service with adaptive QoS guarantee functions, and designs the FMS to implement of prototype system. In multimedia teleconference service, FMS is able to realize the one of multimedia communication services flexibly for service requests and QoS requests from users.
YAAB (Yet Another AST Browser): Using OCL to Navigate ASTs
Authors: G. Antoniol, M. Di Penta, E. Merlo
Venue: Proceedings of the 11th IEEE International Workshop on Program Comprehension (2003)

In the last decades several tools and environments defined and introduced languages for querying, navigating and transforming abstract syntax trees. These environments were meant to support software maintenance, reengineering and program comprehension activities.Instead of introducing a new language, this paper proposes to adopt the Object Constraint Language (OCL) to express queries over an object model representing the abstract syntax tree of the code to be analyzed. OCL is part of the UML lingua franca and thus several advantages can be readily obtained. Central to the idea is to shift the analysis paradigm from a tree-based to an object-oriented paradigm, and to provide a meta-model decoupling the query language from the target language.This paper presents the current status in implementing an OCL interpreter with the ability of querying an object model representing the abstract syntax tree, as well as some interesting applications, such as extracting software metrics or computing clones.
Architecture of a fast motion estimator for MPEG video coding
Venue: Proceedings of the 1996 International Symposium on Parallel Architectures, Algorithms and Networks (1996)

This paper describes the design of a high speed motion estimator using the 2-D log search algorithm. The architecture consists of 5 simple processing elements (PE) where each PE is capable of computing the sum-of-absolute-difference (SAD) to exploit the parallelism. For each step in the 2-D log search procedure, the 5 SADs of the 5 search points are computed in parallel. The design is implemented using Verilog and synthesized using Synopsys. Such a chip would be able to generate the motion vector for each 16*16 macroblock in 14.58 /spl mu/s for 3-step log search, and 24.30 /spl mu/s for 5-step log search. The architecture is well suited for encoding MPEG2 video up to MP@ML.
On small dense arcs in Galois planes of square order
Authors: Giorgio Faina, Massimo Giulietti
Venue: Discrete Mathematics (2003)

In the Galois projective plane of square order q, we show the existence of small dense (k,4)-arcs whose points lie on two conics for q odd, and on two hyperovals for q even. We provide an explicit construction of (4 √q - 4, 2)-arcs for q even, and we also show that they are complete as far as q ≤ 1024.
Integrated multimedia medical data agent in E-health
Authors: Jinman Kim, David Dagan Feng, Tom Weidong Cai, Stefan Eberl
Venue: Proceedings of the Pan-Sydney area workshop on Visual information processing - Volume 11 (2001)

E-Health is producing a great impact in the field of information distribution of the health services to the intra-hospital and the public. Previous research have addressed the development of system architectures in the aim of integrating the distributed and heterogeneous medical information systems. The easing of difficulties in the sharing and management of medical data and the timely accessibility to these data is a critical need for health care providers. We have proposed a client-server agent that allows a portal to the every permitted Information System of the Hospital that consists of PACS, RIS and HIS via the Intranet and the Internet. Our proposed agent enables remote access into the usually closed information system of the hospital and a server that indexes all the medical data which allows for in-depth and complex search queries for data retrieval.
Mathematics and Information Retrieval
Authors: Gerard Salton
Venue:  (1978)

The development of a given discipline in science and technology often depends on the availability of theories capable of describing the processes which control the field and of modelling the interactions between these processes. The absence of an accepted theory of information retrieval has been blamed for the relative disorder and the lack of technical advances in the area. The main mathematical approaches to information retrieval are examined in this study, including both algebraic and probabilistic models, and the difficulties which impede the formalization of information retrieval processes are described. A number of developments are covered where new theoretical understandings have directly led to the improvement of retrieval techniques and operations.
Cyclically 5-edge Connected Con-bicritical Critical Snarks
Authors: Stefan Gruenewald, Eckhard Steffen
Venue:  (1997)

Snarks are bridgeless cubic graphs with chromatic index $\chi'' = 4$. A snark $G$ is called critical if $\chi''(G-\{v,w\}) = 3$, for any two adjacent vertices $v$ and $w$.
Faster Possibility Detection by Combining Two Approaches
Authors: Scott D. Stoller, Fred B. Schneider
Venue:  (1995)

A new algorithm is presented for detecting whether a particular computation of an asynchronous distributed system satisfies $\Poss\Phi$ (read ``possibly $\Phi$''''), meaning the system could have passed through a global state satisfying $\Phi$. Like the algorithm of Cooper and Marzullo, $\Phi$ may be any global state predicate; and like the algorithm of Garg and Waldecker, $\Poss\Phi$ is detected quite efficiently if $\Phi$ has a certain structure. The new algorithm exploits the structure of some predicates $\Phi$ not handled by Garg and Waldecker''s algorithm to detect $\Poss\Phi$ more efficiently than is possible with any algorithm that, like Cooper and Marzullo''s, evaluates $\Phi$ on every global state through which the system could have passed. A second algorithm is also presented for off-line detection of $\Poss\Phi$. It uses Strassen''s scheme for fast matrix multiplication. The intrinsic complexity of off-line and on-line detection of $\Poss\Phi$ is discussed.
A Methodology for the Automated Introduction of Design Patterns
Authors: M. O'Cinnéide, P. Nixon
Venue: Proceedings of the IEEE International Conference on Software Maintenance (1999)

In reengineering legacy code it is frequently useful to introduce a design pattern in order to add clarity to the system and thus facilitate further program evolution. We show that this type of transformation can be automated in a pragmatic manner and present a methodology for the development of design pattern transformations. We address the issues of the definition of a starting point for the transformation, the decomposition of a pattern into mini-patterns and the development of corresponding mini-transformations that can introduce these mini-patterns to a program. We argue that behaviour preservation is a key issue and develop a rigorous argument of this for each mini-transformation we discover. The architecture of an existing software prototype is also discussed and the results of applying this methodology to develop a transformation for the Factory Method pattern are presented.
FAST SIMULATION OF PACKET LOSS RATES IN A SHARED BUFFER COMMUNICATIONS SWITCH
Authors: Shang Cheng-Chang, Philip Heidelberger, Perwez Shahabuddin
Venue:  (1993)

This paper describes an efficient technique for estimating, via simulation, the probability of buffer overflows in a queueing model that arises in the analysis of ATM (Asynchronous Transfer Mode) communication switches. There are multiple streams of (autocorrelated) traffic feeding the switch that has a buffer of finite capacity. Each stream is designated as either being of high or low priority. When the queue length reaches a certain threshold, only high priority packets are admitted to the switch''s buffer. The problem is to estimate the loss rate of high priority packets. An asymptotically optimal importance sampling approach is developed for this rare event simulation problem. In this approach, the importance sampling is done in two distinct phases. In the first phase, an importance sampling change of measure is used to bring the queue length up to the threshold at which low priority packets get rejected. In the second phase, a different importance sampling change of measure is used to move the queue length from the threshold to the buffer capacity.
Advanced Engine Diagnostics Using Artificial Neural Networks
Authors: Stephen O. T. Ogaji, Riti Singh
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

Gas turbines are used for aero and marine propulsion, power generation and as mechanical drives for a wide range of industrial applications. Often, they are affected by gas path faults which have hitherto been diagnosed by techniques such as fault matrixes, fault trees and gaspath analysis. In this paper, a artificial neural network system The system is trained to detect, isolate and assess faults in some of the components of a single spool gas turbine. The hierarchical diagnostic methodology adopted involves a number of decentralised networks trained to handle specific tasks. All sets of networks were tested with data not used for the training process. The results show that significant benefits can be derived from the actual application of this technique.
Plausible Inference Based on Maximum Entropy
Authors: Gerald S. Plesniewicz
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

Some explication of inference method based on maximum entropy is presented. It is shown then a kind of transitive closure can be applied to speed up inferences.
The Type System of a Higher-Order Logic Programming Language
Authors: Gopalan Nadathur, Frank Pfenning
Venue:  (1992)

The type system of the logic programming language $\lambda$Prolog is discussed. The incorporation of higher-order notions within this language requires the use of a typing scheme to distinguish between expressions of different function types. Thus $\lambda$Prolog is a (strongly) typed language, in contrast to the typeless language that underlies the idea of descriptive types in logic programming. The typing discipline that is employed in the language is based on the notion of simple types in the $\lambda$-calculus. This form of typing enforces arity restrictions on functions and predicates and provides a builtin functional hierarchy over terms. The language contains a facility for defining new primitive types and thus permits finer grained distinctions to be introduced by the user. Further, the use of type variables and type constructors provides a form of polymorphism that is similar in certain respects to that present in the language ML. The notion of type checking in $\lambda$Prolog is discussed and shown to be an operation that can be performed at the time of compilation. The value of typing distinctions in determining the clarity of programs and their usefulness in conjunction with type checking in preventing run-time errors due to type violations is also discussed. In addition to their function in type checking, types also have a major role in determining computations in the logic programming context. We discuss this aspect of types that is in contrast to their behavior in other programming paradigms and we show how this leads to a presence of types in the runtime environment. While typing has several advantages, it is sometimes to the programmer''s advantage to be able to omit their mention. Type reconstruction provides a means for filling missing type information in and we discuss issues pertinent to this process in the context of $\lambda$Prolog.
NESL: A Nested Data-Parallel Language
Authors: Guy E. Blelloch
Venue:  (1992)

This report describes NESL, a strongly-typed, applicative, data-parallel language. NESL is intended to be used as a portable interface for programming a variety of parallel and vector supercomputers, and as a basis for teaching parallel algorithms. Parallelism is supplied through a simple set of data-parallel constructs based on vectors, including a mechanism for applying any function over the elements of a vector in parallel and a rich set of parallel functions that manipulate vectors. NESL fully supports nested vectors and nested parallelism--the ability to take a parallel function and apply it over multiple instances in parallel. Nested parallelism is important for implementing algorithms with complex and dynamically changing data structures, such as required in many graph and sparse matrix algorithms. NESL also provides a mechanism for calculating the asymptotic running time for a program on various parallel machine models, including the parallel random access machine (PRAM). This is useful for estimating running times of algorithms on actual machines and, when teaching algorithms, for supplying a close correspondence between the code and the theoretical complexity. This report defines NESL and describes several examples of algorithms coded in the language. The examples include algorithms for median finding, sorting, string searching, finding prime numbers, and finding a planar convex hull. NESL currently compiles to an intermediate language called VCODE, which runs on the Cray Y-MP, Connection Machine CM-2, and Encore Multimax. For many algorithms, the current implementation gives performance close to optimized machine-specific code for these machines.
Low-Overhead Protocols for Fault-Tolerant File Sharing
Authors: Lorenzo Alvisi, Sriram Rao, Harrick M. Vin
Venue: Proceedings of the The 18th International Conference on Distributed Computing Systems (1998)

In this paper, we quantify the adverse effect of file sharing on the performance of reliable distributed applications. We demonstrate that file sharing incurs significant overhead, which is likely to triple over the next five years. We present a novel approach that eliminates this overhead. Our approach:(1.) tracks causal dependencies resulting from file sharing using determinants, (2) efficiently replicates the determinants in the volatile memory of agents to ensure their availability during recovery, and (3)reproduces during recovery the interactions with the file server as well as the file data lost in a failure. Our approach allows agents to exchange files directly, without first saving the files on disks at the server. As a consequence, the cost of supporting file sharing and message passing in reliable distributed applications become virtually identical. The result is a simple, uniform approach, which can provide low-overhead fault-tolerance to applications in which communication is performed through message passing, file sharing, or a combination of the two.
To queue or not to queue?: When FCFS is better than PS in a distributed system
Authors: Mor Harchol-Balter, Mark Crovella, Cristina Murta
Venue:  (1997)

Abstract We examine the question of whether to employ the first-come-first-served (FCFS) discipline or the processor-sharing (PS) discipline at the nodes in a distributed server system. We are interested in the case in which service times are drawn from a heavy-tailed distribution, and so have very high variability. Traditional wisdom in such a situation would prefer the PS discipline, because it allows small tasks to avoid being delayed behind large tasks in a queue. However, we show that system performance can actually be significantly better under FCFS queueing, if a particular kind of task assignment is used. By task assignment, we mean an algorithm that inspects incoming tasks and assigns them to hosts for service. The policy we propose is called SITA-E: Size Interval Task Assignment with Equal Load; it is a static policy that does not incorporate feedback knowledge of the state of the hosts. Surprisingly, under SITA-E, FCFS queueing typically outperforms the PS discipline by a factor of about two, as measured by mean waiting time and mean slowdown (waiting time of task divided by its service time). We analyze the FCFS/SITA-E policy and compare it to the processor-sharing case; in addition we compare it in simulation to a number of other policies. We show that the benefits of SITA-E are present even in small-scale distributed systems (four or more hosts), and that SITA-E can in many cases be more effective than a dynamic policy that takes into account the current load at each host. Finally we discuss issues in employing this policy in distributed Web servers.