ppxscal/embedding_network huggingface dataset:
On Sparse Oracles Separating Feasible Complexity Classes
Authors: Juris Hartmanis, Lane A. Hemachandra
Venue:  (1985)

This note clarifies which oracles separate NP from P and which do not. In essence, we are changing our research paradigm from the study of which problems can be relativized in two conflicting ways to the study and characterization of the class of oracles achieving a specified relativization. Results of this type have the potential to yield deeper insights into the nature of relativization problems and focus our attention on new and interesting classes of languages. A complete and transparent characterization of oracles that separate NP from P would resolve the long-standing P =? NP question. In this note, we settle a central case. We fully characterize the sparse oracles separating NP from P in worlds where P = NP. We display related results about coNP, E, NE, coNE, and PSPACE.
Fast Parallel Algorithms for the Modular Decomposition
Authors: Mark B. Novick
Venue:  (1989)

A module in a graph is like a black box: all the vertices in the module look the same to vertices not in the module. This paper gives the first $NC$ algorithm for finding the modular decomposition of a graph. The algorithm runs in $O$(log $n$) time using $O(n^{3})$ processors on a CRCW PRAM. This decomposition is used to obtain fast sequential and parallel algorithms for solving graph problems on graphs of bounded module size, e.g. the class of cographs where each module with more than one vertex is either disconnected or its complement is disconnected. These graph problems include minimum coloring, maximum clique, matching, Hamiltonian circuit, and maximum cut. Many of these problems can be solved with $O(n^{3})$ processors in $O$(log $n$) time. All of them can be solved in $NC$. Our modular decomposition algorithm can be used to obtain more efficient algorithms for recognizing and orienting comparability graphs.
How Modeling Methods Affect the Process of Architectural Design Decisions: A Comparative Study
Authors: Tetsuo Tamai
Venue: Proceedings of the 8th International Workshop on Software Specification and Design (1996)

A number of modeling methods have been proposed and practiced for the analysis process of software development. As many modeling methods cover the design process as well, it would be natural to ask how those methods affect the critical decisions made during the transition phase from the analysis to the architectural design, but little research activities seem to be visible tackling this problem. The reasons might be the difficulties of finding an appropriate approach and an appropriate comparison framework. We take an approach of analyzing a set of case studies that treat a common example problem and use a formal method to clarify critical design issues. This paper reports some significant results obtained by the analysis of example problem solutions, based on a formally described comparison framework.
Predicting the characteristic curve of a spacer grid spring by finite element analysis
Authors: S. P. Heo, K. H. Yoon, K. N. Song
Venue: Proceedings of the sixth conference on Computational structures technology (2002)

In this paper, three-dimensional finite element analysis is performed to obtain the characteristic curve of the spacer grid spring uniquely designed by KAERI. Several boundary conditions are considered to simulate the characteristic test. The appropriate boundary condition and the analysis procedure for obtaining the characteristic curve of the grid spring are proposed by comparing the finite element results with the test results. The developed analysis procedure will be adequate for predicting the characteristic curve of the grid spring. The minor shape change is also made to overcome a shortcoming of the new grid spring that its maximum load is relatively small for the established springs. A good shape design is found and the characteristics of the final design are compared with those of the initial design.
A library-based 4D visualisation of construction processes
Authors: T. Adjei-Kumi, A. Retik
Venue: Proceedings of the IEEE Conference on Information Visualisation (1997)

The lack of tools for activity level visualisation of construction projects presents problems to planners when considering the future implications of their decisions. Current research into the application of computer graphics to construction planning goes not as far as the component level of a building. Though desirable, this approach does not match the efforts of planners who have to work at the activity level. The work acknowledges the above problem and proposes a new approach. The paper presents a strategic framework for the realistic visualisation of simulations of construction projects at the activity and component levels. This strategy is based on the use of virtual reality (VR) technology to support practitioners to plan and visualise their plans in a near reality sense. It proposes the use of a pre-prepared library of 3D graphical images of building components, facilities etc. and their related activities which constitutes the 'resource pool' on which this strategy thrives.
A Framework for Designing Materialized Views in Data Warehousing Environment
Authors: Jian Yang, Kamalakar Karlapalem, Qing Li
Venue: Proceedings of the 17th International Conference on Distributed Computing Systems (ICDCS '97) (1997)

Data warehouses are accessed by different queries with different frequencies. The portions of data accessed by a query can be treated as a view. When these views are related to each other and defined over overlapping portions of the base data, then it may be more efficient not to materialize all the views, but rather to materialize certain ``shared views'' from which the query results can be generated. In this paper, we address some issues related to determining this set of shared views to be materialized in order to achieve the best combination of good performance and low maintenance, and provide an algorithm for achieving this goal.
A Field Usability Evaluation of a Wearable System
Authors: Jane Siegel, Malcolm Bauer
Venue: Proceedings of the 1st IEEE International Symposium on Wearable Computers (1997)

This empirical field study describes the wearable system, the study method used, and summarizes the experiences of aircraft maintenance specialists who participated in a field usability evaluation conducted at their United States Air Force Reserve facility in the summer of 1996. This usability evaluation aimed at collecting accurate, detailed information for use in the evolutionary design and development of wearable systems for vehicle maintenance workers. All participants were able to complete their tasks using the wearable prototype and they expressed willingness to use such a system in the future. Also, we report on future requirements for wearable maintenance aids elicited from these users.
Morphologically Realistic Neural Networks
Authors: Regina Celia Coelho, Luciano da Fontoura Costa
Venue: Proceedings of the Third IEEE International Conference on Engineering of Complex Computer Systems (1997)

This paper presents how morphologically more realistic artificial neural networks have been obtained by using vectorial- stochastic grammars and used as subsidies for modeling biological neural systems and developing novel artificial neural structures. The paper includes the description of the vectorial-stochatic grammars, a review of the primate striate cortex, a mathematical analysis of the principles under- lying orientation encoding by centric domains, and the development and application of morphologically realistic neural centric models of orientation encoding.
Domain Decomposition for a Mixed Finite Element Method in Three Dimensions
Authors: Z. Cai, R. R. Parashkevov, T. F. Russell, X. Ye
Venue:  (1996)

We consider the solution of the discrete linear system resulting from a mixed finite element discretization applied to a second-order elliptic boundary value problem in three dimensions. Based on a decomposition of the velocity space, these equations can be reduced to a discrete elliptic problem by eliminating the pressure through the use of substructures of the domain. The practicality of the reduction relies on a local basis, presented here, for the divergence-free subspace of the velocity space. We consider additive and multiplicative domain decomposition methods for solving the reduced elliptic problem, and their uniform convergence is established.
Modeling Fault-Tolerant Computer, Network and Control Systems
Authors: Malathi Veeraraghavan, B J Dugan
Venue:  (1988)

Many computer and control systems have been modeled using analytic methods for dependability and performance measures. In this report, we consider several system architectures and their models and find the features unique to each system in an attempt to evaluate the modeling process. In some cases, different models of a system are considered to compare model specification and solution methods. The main modeling concept used in most of these systems is {\em truncation} [1], in order to avoid generating an extremely large model. Largeness avoidance [2] is found to be a good method to handle large complex systems. These truncated models usually give results with bounds that are tight enough for the purpose of the analysis. Both combinatorial and Markov models are compared for some of the systems. For each system, we briefly describe the architecture and its model as used in the original reference and than point out any interesting modelling aspects. There are three main classes of systems being described here: networks, computer systems, and control systems. Section 2 describes three networks, the AIPS I/O network, multi-loop topologies for LANs, and three multi-stage interconnection networks. Section 3 describes two computer architectures, the Cm* multiprocessor system and the ARCS system. Seven different types of control systems are described in Section 4, a hydraulic controller, two jet engine controllers, a railroad control system, a nuclear power plant monitor, digital fly-by-wire flight control system for a tilt-rotor aircraft, and the flight control system IAPSA II. We discuss some of the modeling features of these systems in Section 5. The order of presenting the systems before discussing the interesting modeling features has been used so as to motivate the need for these modeling techniques. The modeling techniques discussed are in the HARP [3], SHARPE [4], and CAME [5,6] frameworks.
Experience with FADE for the Visualization and Abstraction of Software Views
Authors: Aaron J. Quigley
Venue: Proceedings of the 10th International Workshop on Program Comprehension (2002)

This paper describes the FADE paradigm for visualization and a series of experiments for the fast layout, abstract representation, and measurement of software views. In program comprehension, graph models are typically used to represent relational information where the visualization of such graphs is referred to as graph drawing. Here we present the results of aninvestigation into efficient techniques for drawing and abstractly representing large software views with thousands of nodes from four medium sized software systems. The paradigm presented in this paper marries a solution to problems of computation time, screen space,cognitive load, and rendering for large-scale drawings using a single graph model.
Scalable Resource Scheduling: Design, Assessment, Prototyping
Authors: M. Kapelevich, O. Kremien
Venue: Proceedings of the 8th Israeli Conference on Computer-Based Systems and Software Engineering (1997)

Resource scheduling in distributed systems aims at achieving maximal system performance by utilizing the available system resources efficiently. Large distributed systems, comprising hundreds or thousands of nodes and spanning vast geographical distances (e.g. Internet), require resource scheduling to be scalable. Scalability has become a common requirement in the design and development of distributed software. This paper describes a comprehensive approach to software development, leading from the stage of requirements specification, through design and algorithm assessment to a prototype implementation of a scalable resource scheduling policy. Scalability is achieved by system partitioning. Communication delays may limit scalability and degrade system performance. In this work, delays are considered by taking in account resource proximity in the scheduling policy. The paper demonstrates performance results obtained in simulation under communication and computation overload conditions. The simulation code is later used for prototype implementation. Finally, we examine the software design issues and applicability of the prototype to different distributed environments, providing the example of PVM [Geist94].
ULTIMA RATIO- A Visual Language for Argumentation
Authors: Daniela A. Plewe
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

In the third act of Shakespeare's Hamlet, the hero is unsure whether to kill Claudius - the assassin of Hamlet's father - or not. He argues that if he does kill him, Claudius who is praying at that very moment goes to heaven and if he does not kill him Hamlet's father is not revenged. A contradiction.Ultima Ratio aims at formalization and visualization of argumentation for agents. An agent is constituted by a set of arguments and assumptions. Facing a particular world, the agent's believes may be inconsistent triggering a rational monologue to deal with the situation.Formally, we define a framework for argumentation based on extended logic programming under well-founded semantics. The system serves as decision support and is capable of detecting and removing contradictions and deriving conclusions of the agent's arguments.To demonstrate the structure and dynamics of the agent's argumentation, we visualise the process as dynamic construction of proof trees. The paper includes screenshots of the logical engine and the visualisation unit as exhibited at the computer arts exhibition Ars Electronica 98.
Web based image authentication using invisible Fragile watermark
Authors: Yusuk Lim, Changsheng Xu, David Dagan Feng
Venue: Proceedings of the Pan-Sydney area workshop on Visual information processing - Volume 11 (2001)

The demand of security is getting higher in these days due to easy reproduction of digitally created multimedia data. Digital watermark is the emerging technique to embed secret information into content for copyright protection and authentication. Watermark is embedded within an image that alteration and modification to the watermarked image can be detected in a fragile watermark system. Watermark detection is blind that does not require an original image and it is invisible to avoid revealing secret information to malicious attackers. A web based image authentication method based in digital watermarking is described in this paper. It can provide more controls to image owners and conveniences to clients who want to get authenticity of image by integrating benefits of using Internet to the watermark system.
Search Strategies for Hybrid Search Spaces
Authors: Carla Gomes, Bart Selman
Venue: Proceedings of the 11th IEEE International Conference on Tools with Artificial Intelligence (1999)

Recently, there has been much interest in enhancing purely combinatorial formalisms with numerical information. For example, planning formalisms can be enriched by taking resource constraints and probabilistic information into account. The Mixed Integer Programming (MIP) paradigm from Operations Research provides a natural tool for solving optimization problems that combine such numeric and non-numeric information. The MIP approach relies heavily on linear program relaxations and branch-and-bound search. This is in contrast with depth-first or iterative deepening strategies generally used in AI. We provide a detailed characterization of the structure of the underlying search spaces as explored by these search strategies. Our analysis indicates that the traditional approach of identifying dominating search strategies for a given problem domain is inadequate. We show that much can be gained from combining search strategies for solving hard MIP problems, thereby leveraging the strength of different search strategies regarding both the combinatorial and numeric components of the problem.
Generic Abstract Interpretation Algorithms for Prolog: Two Optimization Techniques and Their Experimental Evaluation
Authors: Vincent Englebert, Baudouin L Charlier, Didier Roland, Pascal Van Hentenryck
Venue:  (1991)

The efficient implementation of generic abstract interpretation algorithms for Prolog is reconsidered. Two new optimization techniques are proposed and applied to the original algorithm of [15]: dependency on clause prefixes and caching of operations. The first improvement avoids reevaluating a clause prefix when no abstract value which it depends on has been updated. The second improvement consists of caching all operations on substitutions and reusing the results whenever possible. The algorithm together with the two optimization techniques have been implemented in $C$ (about 8000 lines of code each), tested on a large number of Prolog programs, and compared with the original implementation on an abstract domain containing modes, types, and sharing. In conjuction with refinements of the domain algorithms, they produce an average reduction of more than 58\ Extensive experimental results on the programs are given, including computation times, memory consumption, hit ratios for the caches, the number of operations performed, and the time distribution. As a main result, the improved algorithms exhibit the same efficiency as the specific tools of [29, 10], despite the fact that our abstract domain is more sophisticated and accurate. The abstract operations also take 90\ that the room left for improvement is very limited. Results on a simpler domain are also given and show that even extremely basic domains can benefit from the optimizations. The general-purpose character of the optimizations is also discussed.
A Characterization Study of NCSTRL Distributed Searching
Authors: Naomi Dushay, James C. French, Carl Lagoze
Venue:  (1999)

NCSTRL, the Networked Computer Science Technical Reference Library, is a federated digital library based on the Dienst architecture. One aspect of this architecture is distributed searching, with digital library queries being dispatched from query routers to globally distributed indexers that process them and return results. We studied user data for a two-month period at five query routers in order to characterize some key performance aspects of distributed searching in an operational digital library. This study uncovered the following characteristics. Query processing at NCSTRL servers involves significant time waiting for responses from indexers. Each indexer''s availability and response times appear unique to each query router. Different indexers'' availability and response times are not similar from the viewpoint of a single query router. Query router waiting time for indexers is larger than indexer processing time, implying that communication time over the network is significant. We close by examining the breakdown of NCSTRL queries: the number of fielded vs. non-fielded queries, and the complexity of these queries.
Applying Explanation-Based Learning to Natural language Processing (2)
Authors: Christer Samuelsson, Manny Rayner
Venue:  (1989)

Explanation-based learning is a technique which attempts to optimiz performance of a rule-based system by adding new rules constructed from generalizations of successfully-solved examples. The paper summarizes previous work showing how this idea can be used in natural language processing, and describes experiments in which the EBL method was applied to the CHAT-80 system of Pereira and Warren. In particular, we address the problem of assuring the utility of learning a rule, since the benefit of a learned rule may not outweigh the increased search time incurred in checking its applicability. We show that this problem can be overcome in the NL domain by indexing acquired rules by their lexical constraints, which in general vastly reduces the number of potentially applicable rules. Such an indexing method was implemented and timing studies were made comparing its access speed to that of normal linear search. The indexing scheme required an average access time of 35 - 40 ms independent of the number of learned rules. The results suggest that the overhead of the indexing scheme is small.
Deadline-Constrained Causal Order
Authors: L. Rodrigues, R. Baldoni, E. Anceaume, M. Raynal
Venue: Proceedings of the Third IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (2000)

A causal ordering protocol ensures that if two messages are causally related and have the same destination, they are delivered to the application in their sending order. Causal order strongly simplifies the development of distributed object-oriented systems.To prevent causal order violation, either messages may be forced to wait for messages in their past, or late messages may have to be discarded. For a real-time setting, the first approach is not suitable since when a message misses a deadline, all the messages that causally depend on it may also be forced to miss their deadlines.We propose a novel causal ordering abstraction that takes messages deadlines into consideration. Two implementations are proposed in the context of multicast and broadcast communication that delivers as many messages as possible to the application. Examples of distributed soft real-time applications that benefit from the use of a deadline-constrained causal ordering primitive are given.
Information systems as social systems
Authors: Niek F. du Plooy
Venue: Critical reflections on information systems: a systemic approach (2003)

Since the very early days of computing, information systems were regarded as "man-machine" systems. This definition is of far greater importance to the teaching of information systems as well as to the profession of information systems developers than is often recognised. The majority of teachers, and textbooks, are still caught in the paradigm that information systems development is a technical "art" rather than a field that concerns sociological, rather than technical problems. This chapter argues that the "human" or sociological side of information systems is of such importance that it should be seen as the core of the discipline, and that information systems are best understood when viewed as social systems.Examining the nondeterministic nature of information systems and applying Ashby's Law of Requisite Variety are helpful to describe and explain these systems as social systems. The paper also refers to current thinking on systems (especially soft systems methodology) and its place in supporting information systems in a constantly changing environment.Finally, the implications of viewing information systems as social systems are discussed with respect to teaching and research, the impact of information systems on organizations, and the shortcomings of current software engineering methodologies.
Group analysis of the von K&#x00E1;rm&#x00E1;n--Howarth equation. Part I. Submodels
Authors: S. V. Khabirov, G. Ünal
Venue: Communications in Nonlinear Science and Numerical Simulation (2002)

We study the von Kármán-Howarth (KH) equation by group theoretical methods. This scalar partial differential equation involves two dependent variables (closure problem) and, it has been derived from the Navier-Stokes equations. The equivalence Lie algebra L has been found to be infinite-dimensional and, it is spanned by the four operators. The subalgebra of L is spanned by the three operators. Furthermore, ideal comprises one operator. Optimal systems of one-, two- and three-dimensional subalgebras have been obtained. Normalizers for the one- and two-dimensional subalgebras have been calculated. Finally we have obtained the submodels of the KH equation corresponding to optimal system of one- and two-dimensional subalgebras. This merely suggests alternative solutions to the closure problem of isotropic turbulence.