ppxscal/embedding_network huggingface dataset:
Routing guaranteed quality of service connections in integrated services packet networks
Authors: Wei Zhao, S. K. Tripathi
Venue: Proceedings of the 1997 International Conference on Network Protocols (ICNP '97) (1997)

A critical functional component of quality-of-service (QoS) deployment in packet-switched networks is QoS-based routing. In this paper, we present a routing solution for guaranteed quality-of-service connections in integrated services packet networks (ISPN)-the future QoS-capable Internet proposed by the IETF. The problem is in essence a path finding problem with both end-to-end delay and per-node buffer constraints, in networks with heterogeneous intermediate switching nodes. We present a polynomial time algorithm using a capacity plane decomposition technique combined with a per-node constrained shortest path algorithm. We further propose an efficient route computation architecture, based on a novel metric-separation approach, to a slightly restricted version of the problem. The strategy is somewhat similar to "route caching", but in a new and broader sense.
Reliability Analysis of Interconnection Networks Using Hierarchical Composition
Authors: T J Blake, S K Trivedi
Venue:  (1988)

With the increased use of multiprocessor systems, interconnection networks have attracted considerable attention. Since the number of processors and memories in these systems is $O(N)$, whereas the number of switching elements in the MIN is $O(N log N)$, the reliability of a multiprocessor system is dominated by the reliability of the interconnection network [4]. It is for this reason that several proposals for fault-tolerant MINs have been made. In order to properly compare the effectiveness of different schemes, analytic reliability models are necessary. However, exact reliability analysis of all but a trivial set of interconnection networks is intractable. Upper- and lower-bound block diagram models are commonly used to bound the reliability of such networks, but these models assume perfect coverage and no repair. Based on the nature of the upper- and lower-bound block diagram models of interconnection networks, we generalize and consider a series system consisting of $s$-independent subsystems. In order to model the reliability of such a system with on-line repair and imperfect coverage, the normal approach would be to construct and solve a large, overall Markov model. Instead, we propose a two-level hierarchical model in which each subsystem is modeled as a Markov chain and the overall system reliability is then modeled as a series system of $s$-independent ``Markov'''' components. We extend this technique to compute the point availability of the system with imperfect coverage and $s$-independent repair. We also show how three-level hierarchical composition can be used to obtain a closed-form expression for approximating the availability of a series of subsystems where an individual subsystem may have $m$ components in parallel. We have thus extended the size of problems for which reliability/availability, incorporating imperfect coverage and on-line repair, can be computed without resorting to a large, one-level Markov model. Extensions to allow for transient faults and phase-type repair time distributions are straightforward. It should be possible to apply our approach to other fault-tolerant MINs. The approach that we discuss is also applicable to any system that can be modeled as a series system where each subsystem is a parallel redundant system.
Metrics of Software Evolution as Effort Predictors - A Case Study
Authors: Juan F. Ramil, Meir M. Lehman
Venue: Proceedings of the International Conference on Software Maintenance (ICSM'00) (2000)

Despite its importance, cost estimation in the context of continuing software evolution has been relatively unexplored. This paper addresses this omission by describing some models that predict effort as a function of a suite of metrics of software evolution. It presents a case study relating to the evolution of the kernel of a mainframe operating system. Six models based on eight different indicators of evolution activity are proposed; their predictive power is examined and compared to that of two baseline models. Predictions with errors of the order of 20 percent of the actual values have been obtained from the models, when fitted and tested to historical data over a segment of 10 years of kernel's continuing evolution. Appropriateness of the proposed models as predictors appears to be restricted to homogeneous evolution segments, that is, periods with relatively small variations in the level of effort applied. It was found that models based on coarse granularity measures, such as ¿subsystem counts¿, provided a Mean Magnitude of Relative Error similar to those based on finer alternatives, such as ¿module counts¿.
Integration Standards for Critical Software Intensive Systems
Authors: Victoria Stavridou
Venue: Proceedings of the 3rd International Software Engineering Standards Symposium (ISESS '97) (1997)

"Integration''\index{integration} is a term often misused and misunderstood. The existence of integration as an activity in system development is undeniable. Its existence as a phase of the system lifecycle which requires planning and management is, however, frequently ignored. This omission is undesirable, particularly in critical systems where lack of integration planning may affect the system's ability to meet its criticality objectives. Not surprisingly, this confusion is reflected in many standards. It is the purpose of this paper to identify the way various critical systems standards deal with integration and, as a corollary, to suggest possible standardization activities as well as ways in which organizations relying on software intensive systems for critical functions can approach this problem.
Internet-Based Teleoperation Using VE Modeling Based on Single Images
Venue: Proceedings of the International Conference on Information Visualisation (2000)

Virtual Environment (VE) techniques provide a powerful tool for the visualization of the 3D environment of a teleoperation work-site, particularly when ¿live¿ video display is inadequate for the task operation or its transmission is constrained, for example by limited bandwidth. However, the ability of VE to cope with the dynamic phenomena of typical teleoperation work-sites is severely limited by its pre-defined model-based nature. Thus, an on-line composing mechanism is needed to make it environment compliant. This paper describes a method for this purpose, based on workspace analysis, in which objects are constructed from simple 2D images, and VEs are modeled interactively. Experiments have shown that the method is convenient and effective for on-line VE editing.
Streamline Design of Stability Parameters For Advection-diffusion Problems
Authors: Isaac Harari, Leopoldo P. Franca, Saulo P. Oliveira
Venue:  (2000)

The dependence of the computation of advective-diffusive transport phenomena on the orientation of the mesh with respect to the flow direction is analyzed. Poor performance of the classical Galerkin finite element method in the convection-dominated regime is alleviated by stabilization. We propose definitions of the stability parameter that rationally incorporate the flow direction. Numerical tests compare the performance of the proposed methods with established techniques.
A fault-tolerant object service on CORBA
Authors: Guang-Way Sheu, Yue-Shan Chang, Deron Liang, Shyan-Ming Yuan, W. Lo
Venue: Proceedings of the 17th International Conference on Distributed Computing Systems (ICDCS '97) (1997)

There are more and more COSS (Common Object Service Specifications) on CORBA (Common Object Request Broker Architecture) announced by the OMG (Object Management Group), but no common specification about fault-tolerance exists. We propose a "warm stand-by" replication approach. When an object (primary object) is invoked, it will invoke a secondary object, and the primary object will log the messages and checkpoint the state to the secondary object periodically. If the primary object fails, the secondary object can take over by way of a client executing a few operations to change the secondary object's mode to primary. Following the style of COSS, we define four interfaces and provide class implementations that can help programmers write programs with fault-tolerant capability. The whole model has been implemented on Orbix, which is a full implementation of CORBA specification.
Visualization of Vortical Flow Using Multiple Slices
Authors: Koji Koyamada, Kazuma Kamisawa, Akio Doi
Venue: Proceedings of the Seventh International Conference on Parallel and Distributed Systems: Workshops (2000)

In the present paper, a new technique is proposed for visualizing a vortical flow field using multiple texture-mapped slices. First, finding and classifying critical points in the flow field identify the vortex centers. Then the flow field is projected onto the slicing planes, which pass through the critical points and are perpendicular to the vortex axes. Finally, the projected flow fields are visualized intuitively by advecting tracers located around the critical points. The resulting images are mapped to rectangles having transparent attributes in a VRML format. The proposed technique is applied to various flow fields and the effectiveness of this technique is confirmed.
Concurrency Control Protocols for Real-Time Databases, Phd Thesis
Authors: Spyridon Braoudakis
Venue:  (1994)

Abstract Concurrency control methods developed for traditional database systems are not appropriate for real-time database systems (RTDBS), where, in addition to database consistency requirements, satisfying timing constraints is an integral part of the correctness criterion. Most real-time concurrency control protocols considered in the literature combine time-critical scheduling with traditional concurrency control methods to conform to transaction timing constraints. These methods rely on either transaction blocking or restarts, both of which are inappropriate for real-time concurrency control because of the unpredictability they introduce. Moreover, RTDBS performance objectives differ from those of conventional database systems in that maximizing the number of transactions that complete before their deadlines becomes the decisive performance objective, rather than merely maximizing concurrency (or throughput). Recently, Speculative Concurrency Control (SCC) was proposed as a categorically different approach to concurrency control for RTDBS. SCC relies on the use of redundant processes ( shadows), which speculate on alternative schedules, once conflicts that threaten the consistency of the database are detected. SCC algorithms utilize added system resources to ensure that correct (serializable) executions are discovered and adopted as early as possible, thus increasing the likelihood of the timely commitment of transactions. This dissertation starts by reviewing the Order-Based SCC (SCC-OB) algorithm which associates almost as many shadows as there are serialization orders of transactions. After demonstrating SCC-OB''s excessive use of redundancy, a host of novel SCC-based protocols is introduced. Conflict-Based SCC (SCC-CB) reduces the number of shadows that a running transaction needs to keep by maintaining one shadow per uncommitted conflicting transaction. It is shown that the quadratic number of shadows maintained by SCC-CB is optimal, covering all serialization orders produced by SCC-OB. SCC-CB''s correctness is established by showing that it admits only serializable histories. Next, the trade-off between the number of shadows and timeliness is considered. A generic SCC algorithm (SCC-kS) that operates under a limited redundancy assumption is presented; it allows no more than a constant number $k$ of shadows to coexist on behalf of any uncommitted transaction. Next, a novel technique is proposed that incorporates additional information such as deadline, priority and criticalness within the SCC methodology. SCC with Deferred Commit (SCC-DC) utilizes this additional information to improve the timeliness through the controlled deferment of transaction commitments. A probabilistic Value Induced Shadow Allocation (VISA) policy is developed which aims at preserving the most valuable shadows for each system transaction. The thesis of this dissertation is that SCC-based algorithms offer a new dimension, redundancy, to improve the timeliness of RTD
Performance evaluation of a WDMA OIDSM multiprocessors
Authors: I-Shyan Hwang
Venue: Proceedings of the 1996 International Conference on Parallel and Distributed Systems (1996)

Optically interconnected distributed shared memory (OIDSM) systems offer significant performance advantages due to the fast interconnection network. The photonic network of the proposed approach is based on a wavelength-division multiplexed (WDMA) passive star-coupled configuration. Optical self-routing is achievable which partitions the traffic, relaxing the design constraints on the receiver subsystem since a node now only receives and processes a fraction of the network traffic. A major concern with the multi-access approach is that a media access control and a cache coherence protocol are required to provide access to a distributed arbitration of the WDMA photonic network. In particular, one class of media access protocol (TDMAC) requires a control channel to broadcast reservation requests, and the broadcast capability is also able to support coherence level control signals such as invalidations which enable a snooping based coherence protocol. This paper evaluates how OIDSM can ease the traffic in large-scale snooping-based shared memory multiprocessors.
Becoming congress: a longitudinal study of the civic engagement implications of a classroom simulation
Authors: Jeffrey L. Bernstein, Deborah S. Meizlish
Venue: Simulation and Gaming (2003)

Does the content of political science courses affect civic learning? The authors examine whether differences in students' self-reported knowledge, cynicism, and participation depend on whether their American government course included a character-playing simulation. The authors use an innovative longitudinal, quasi-experimental research design to test not only for immediate effects but also for those that differentiated the two groups 3 years after they took the course. Differential effects of the simulation at the end of the particular course are virtually nonexistent. Three years later, however, students who had the simulation reported more understanding of the concepts taught in the simulation than did the control group. They also emerged less politically cynical. No differences were observed, however, on items reflecting political participation.
Applying a Mutation-Based Genetic Algorithm to Processor Configuration Problems
Authors: T L. Lau, E P. K. Tsang
Venue: Proceedings of the 8th International Conference on Tools with Artificial Intelligence (1996)

The Processor Configuration Problem (PCP) is a Constraint Optimization Problem. The task is to link up a finite set of processors into a network, while minimizing the maximum distance between these processors. Since each processor has a limited number of communication channels, a carefully planned layout could minimize the overhead for message switching. In this paper, we present a Genetic Algorithm (GA) approach to the PCP. Our technique uses a mutation based GA, a function that produces schemata by analyzing previous solutions, and an effective data representation. Our approach has been shown to out-perform other published techniques in this problem.
An Evolutionary Approach for Scheduling in Parallel Processor Systems
Authors: Albert Y. Zomaya, Chris Ward, Ben Macey
Venue: Proceedings of the 1997 International Symposium on Parallel Architectures, Algorithms and Networks (1997)

Task Scheduling is essential for the proper functioning of parallel processor systems. Scheduling of tasks onto networks of parallel processors is an interesting problem that is well-defined and documented in the literature. However, most of the available techniques are based on heuristics that solve certain instances of the scheduling problem very efficiently and in reasonable amounts of time. This paper investigates an alternative paradigm, based on genetic algorithms, that can be used to efficiently solve the scheduling problem without the need to apply any restricted assumptions that are problem-specific, like it is the case when using heuristics. The conditions under which a genetic algorithm performs best will also be highlighted. This will be accompanied by a number of examples and case studies.
Selecting the Advanced Encryption Standard
Authors: William E. Burr
Venue: IEEE Security and Privacy (2003)

The National Institute of Standards and Technology selected the Advanced Encryption Standard, a new standard symmetric key encryption algorithm, from fifteen qualifying algorithms. NIST has made efforts to bring other federal cryptographic standards up to AES's level and to update and extend NIST's standard cryptographic modes of operation.
Design of Ternary Schmitt Triggers Based on Its Sequential Characteristics
Authors: Yinshui Xia, Xunwei Wu, Penjung Wang
Venue: Proceedings of the 32nd International Symposium on Multiple-Valued Logic (2002)

By analyzing the working characteristicsof binary Schmitt circuits we find their sequential characteristics, which makesus follow the method of sequential circuits to design Schmitt circuits. Thesequential design technique is extended to the study of ternary Schmitt circuits in thispaper. The designed ternary Schmitt trigger has a similar structure with aternary flip-flop. PSPICE simulation with TTL technology shows that the circuit hascorrect Schmitt characteristics.
Using Integer Equations for High Level Formal Verification Property Checking
Authors: Bijan Alizadeh, Mohammad R. Kakoee
Venue: Proceedings of the 4th International Symposium on Quality Electronic Design (2003)

This paper describes the use of integer equations forhigh level modeling digital circuits for application offormal verification properties at this level. Mostformal verification methods use BDDs, as a low levelrepresentation of a design. BDD operations requireseparation of data and control parts of a design andtheir implementation requires large CPU time andmemory. In our method, a behavioral state machine isrepresented by a list of integer equations, and RT levelproperties are directly applied to this representation.This reduces the need for large BDD data structuresand uses far less memory. Furthermore, this methodis applied to circuits without having to separate theirdata and control sections. Integer equations aresolved recursively by replacement and simplificationoperations. For this implementation, we use acanonical form of integer equations. This papercompares our results with those of the VIS verificationtool that is a BDD based program.
Computing Eigenvalues and Eigenvectors of a Dense Real Symmetric Matrix on the Ncube 6400
Authors: Shirish Chinchalkar
Venue:  (1991)

This report demonstrates parallel versions of the Eispack functions TRED2 and TQL2 for finding all eigenvalues and eigenvectors of a dense, real symmetric matrix on the Ncube 6400. There are several techniques for solving this problem. An efficient and accurate method is tridiagonalization of the original matrix A (TRED2), followed by application of the QR method on the resulting tridiagonal matrix (TQL2). Since the eigenvalues are the roots of a characteristic polynomial, bisection and inverse iteration can be used to compute all eigenvalues and eigenvectors. This method is significantly faster than the QR method provided the eigenvalues are well separated. This technical report will also describe the algorithms TREDs and TQL2 and their parallel counterparts in greater detail. The results of numerical experiments on large problems on a 1024 processors Ncube 6400 are also presented.
Impact on Performance of Fused Multiply-Add Units in Aggressive VLIW Architectures
Authors: David Lopez, Josep Llosa, Eduard Ayguade, Mateo Valero
Venue: Proceedings of the 1999 International Conference on Parallel Processing (1999)

Loops are the main time consuming part of programs based on floating point computations. The performance of the loops is limited either by recurrences in the computation or by the resources offered by the architecture. Several general-purpose superscalar microprocessors have been implemented with multiply-add fused floating-point units, that reduces the latency of the combined operation and the number of resources used.This paper analyses the influence of these two factors in the instruction-level parallelism exploitable from loops executed on a broad set of future aggressive processor configurations. The estimation of implementation costs (area and cycle time) enables a fair comparison of these configurations in terms of final performance and implementation feasibility. The paper performs a technological projection for the next years in order to foresee the possible implementable alternatives. From this study we conclude that multiply-add fused units may have a deep impact in raising the performance of future processor architectures with a reasonable increase in cost.
A New Study on Using HTML Structures to Improve Retrieval
Authors: M. Cutler, H. Deng, S. S. Maniccam, W. Meng
Venue: Proceedings of the 11th IEEE International Conference on Tools with Artificial Intelligence (1999)

Locating useful information effectively from the World Wide Web (WWW) is of wide interest. This paper presents new results on a methodology of using the structures and hyperlinks of HTML documents to improve the effectiveness of retrieving HTML documents. This methodology partitions the occurrences of terms in a document collection into classes according to the tags in which a particular term appears (such as Title, H1-H6, and Anchor). The rationale is that terms appearing in different structures of a document may have different significance in identifying the document. The weighting schemes of traditional information retrieval were extended to include class importance values. We implemented a genetic algorithm to determine a "best so far" class importance factor combination. Our experiments indicate that using this technique the retrieval effectiveness can be improved by 39.6% or higher.
An Adaptive Scheduling Approach in Real-Time CORBA
Authors: Carlos Montez Joni Fraga, Jean-Marie Farines, Rômulo de Oliveira
Venue: Proceedings of the 2nd IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (1999)

CORBA is an emerging middleware infrastructure with open standardization that is receiving a good acceptance since it makes easier to program distributed objects. CORBA is being extended through the specification of interfaces and necessary abstractions to support applications with real-time constraints. These new abstractions will enable a variety of programming models for real-time applications.This paper presents an adaptive programming model for distributed real-time applications using CORBA concepts. The model combines the time polymorphic invocation technique with the (m,k)-firm guarantee.
An exploration of bugs and debugging in multi-agent systems
Authors: David Poutakidis, Lin Padgham, Michael Winikoff
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

Debugging multi-agent systems, which are concurrent, distributed, and consist of complex components, is difficult, yet crucial. In earlier work we have proposed mechanisms whereby protocol specifications available from the design process can be used for monitoring the execution of the multi-agent system they describe. Protocol specifications can be used at run time for reporting any discrepancies in interactions compared to that which was specified. In this paper we describe and categorise a range of bugs found in actual multi-agent systems developed by students in an Agent Oriented Programming and Design class. We then indicate how these bugs manifest to the debugging agent and what information it is able to provide to the user to assist in locating and diagnosing the problem.