ppxscal/embedding_network huggingface dataset:
Crout Versions of ILU for General Sparse Matrices
Authors: Na Li, Yousef Saad, Edmond Chow
Venue: SIAM Journal on Scientific Computing (2003)

This paper presents an efficient implementation of the incomplete LU (ILU) factorization derived from the Crout version of Gaussian elimination. At step k of the elimination, the kth row of U and the kth column of L are computed using previously computed rows of U and columns of L. The data structure and implementation borrow from already known techniques used in developing both sparse direct solution codes and incomplete Cholesky factorizations. This version of ILU can be computed much faster than standard threshold-based ILU factorizations computed rowwise or columnwise. In addition, the data structure allows efficient implementations of more rigorous and effective dropping strategies.
Architectural optimizations for low-power, real-time speech recognition
Authors: Rajeev Krishna, Scott Mahlke, Todd Austin
Venue: Proceedings of the 2003 international conference on Compilers, architecture and synthesis for embedded systems (2003)

The proliferation of computing technology to low power domains such as hand--held devices has lead to increased interest in portable interface technologies, with particular interest in speech recognition. The computational demands of robust, large vocabulary speech recognition systems, however, are currently prohibitive for such low power devices. This work begins anexploration of domain specific characteristics of speech recognition that might be exploited to achieve the requisite performance within the power constraints of such devices. We focus primarily on architectural techniques to exploit the massive amounts of potential thread level parallelism apparent in this application domain, and consider the performance / power trade-offs of such architectures. Our results show that a simple, multi-threaded, multi-pipelined processor architecture can significantly improve the performance of the time-consuming search phase of modern speech recognition algorithms, and may reduce overall energy consumption by drastically reducing dissipation of static power. We also show that the primary hurdle to achieving these performance benefits is the data request rate into the memory system, and consider some initial solutions to this problem.
Power-Aware Branch Prediction: Characterization and Design
Authors: Dharmesh Parikh, Kevin Skadron, Yan Zhang, Mircea Stan
Venue: IEEE Transactions on Computers (2004)

Abstract--This paper uses Wattch and the SPEC 2000 integer and floating-point benchmarks to explore the role of branch predictor organization in power/energy/performance trade offs for processor design. Even though the direction predictor by itself represents less than 1 percent of the processor's total power dissipation, prediction accuracy is nevertheless a powerful lever on processor behavior and program execution time. A thorough study of branch predictor organizations shows that, as a general rule, to reduce overall energy consumption in the processor, it is worthwhile to spend more power in the branch predictor if this results in more accurate predictions that improve running time. This not only improves performance, but can also improve the energy-delay product by up to 20 percent. Three techniques, however, can reduce power dissipation without harming accuracy. Banking reduces the portion of the branch predictor that is active at any one time. A new on-chip structure, the prediction probe detector (PPD), uses predecode bits to entirely eliminate unnecessary predictor and branch target buffer (BTB) accesses. Despite the extra power that must be spent accessing it, the PPD reduces local predictor power and energy dissipation by about 31 percent and overall processor power and energy dissipation by 3 percent. These savings can be further improved by using profiling to annotate branches, identifying those that are highly biased and do not require static prediction. Finally, the paper explores the effectiveness of a previously proposed technique, pipeline gating, and finds that, even with adaptive control based on recent predictor accuracy, pipeline gating yields little or no energy savings.
Adaptive Compressed Caching: Design and Implementation
Authors: Rodrigo S. de Castro, Alair Pereira do Lago, Dilma Da Silva
Venue: Proceedings of the 15th Symposium on Computer Architecture and High Performance Computing (2003)

In this paper, we reevaluate the use of adaptive compressed caching in order to improve system performance through reduction of accesses to the backing stores. We propose a new and simple adaptability policy that adjusts the compressed cache size on-the-fly, and evaluate a compressed caching system with this policy through an implementation in a widely used operating system, Linux.We also redesign compressed caching in order to provide performance improvements for all tested workloads and address the problems faced in previous works and implementations that led to non-conclusive results. Among these fundamental modifications, our compressed cache is the first one to also compress file cache pages, to adaptively disable compression of clean pages when necessary and to address applications with poor compressibility.We tested a system with our adaptive compressed cache under many applications and benchmarks, each one with different memory pressures. The results showed performanceimprovements (up to 171.4%) in all of them if under memory pressure, and minimal overhead (up to 0.39%) when there is very light memory pressure. We believe this work shows that this adaptive compressed cache design should be actually considered as an effective mechanismfor improvement in system performance.
Power Analysis of a General Convolution Algorithm Mapped on a Linear Processor Array
Authors: Rashindra Manniesing, Richard Kleihorst, André Van Der Avoird, Emile Hendriks
Venue: Journal of VLSI Signal Processing Systems (2004)

We explore the energy dissipation of the Linear Processor Array (LPA) as a function of the number of available resources (Processor Units P) within the array. This number P is an important parameter, as it reflects performance, relates parallel processing to energy dissipation, and influences the scaling of the various parts of the LPA architecture (memory, address generator, communication network).To make a comparison of the different design variants for a fixed datawidth possible, we propose a high-level energy dissipation model of the processor, which is based on a detailed analysis of a general convolution algorithm.It is shown that the energy dissipation of the LPA can roughly be described by the relationship Etotal &sim; N/P with N presenting the datawidth in pixels. This relationship is derived from two observations: first, the largest contribution to Etotal is formed by the energy dissipated by the memories, and second, in our model of the LPA, the datawidth of the memories corresponds with the number of pixels N to be processed, which results in an increase of the access rate when P decreases.Furthermore, we have shown that the energy dissipation caused by communication within the LPA, increases with increasing number of resources: the trade-off between communication versus computation in parallel computing. This turns out to be negligible in the total energy dissipation, and we therefore conclude, that the optimum solution is found, when a full number of resources is applied within the LPA.
The vBow: a virtual violin bow controller for mapping gesture to synthesis with haptic feedback
Authors: Charles Nichols
Venue: Organised Sound (2002)

The vBow, a virtual violin bow musical controller, has been designed to provide the computer musician with most of the gestural freedom of a bow on a violin string. Four cable and servomotor systems allow for four degrees of freedom, including the lateral motion of a bow stroke across a string, the rotational motion of a bow crossing strings, the vertical motion of a bow approaching and pushing into a string, and the longitudinal motion of a bow travelling along the length of a string. Encoders, attached to the shaft of the servomotors, sense the gesture of the performer, through the rotation of the servomotor shafts, turned by the motion of the cables. The data from each encoder is mapped to a parameter in synthesis software of a bowed-string physical model. The software also sends control voltages to the servomotors, engaging them and the cables attached to them with a haptic feedback simulation of friction, vibration, detents and elasticity.
Enabling Data Quality Notification in Cooperative Information Systems through aWeb-Service Based Architecture
Authors: C. Marchetti, M. Mecella, M. Scannapieco, A. Virgillito
Venue: Proceedings of the Fourth International Conference on Web Information Systems Engineering (2003)

Cooperative Information Systems (CISs) are often characterized by a high degree of data replication; as an example, in an e-Government scenario, the personal data of citizens are stored by almost all administrations. In such scenarios, organizations typically provide the same information with distinct quality levels and this enables providing users with data of the highest available quality. Furthermore, the comparison of data values might be used to enforce a general improvement of data quality in all organizations. In the DaQuinCIS project1, we propose an architecture for the management of data quality in CISs; this architecture allows the diffusion of data and related quality and exploits data replication to improve the overall quality of cooperative data.In this paper, we present an overview of a component of the DaQuinCIS architecture, namely the Quality Notification Service (QNS), which is used to inform interested users when changes in quality values occur within the CIS. QNS can be used to control the quality of critical data, e.g. to keep track of quality changes and to be always aware when quality degrades under a certain threshold. The interaction between the QNS and its users follows the publish/subscribe paradigm: a user willing to be notified for quality changes subscribes to the QNS by submitting the features of the events to be notified for, through a specific subscription language. When a change in quality occurs, an event is published by the QNS i.e., all the users which have a consistent subscription receive a notification. However, as shown in [6], currently available pub/sub infrastructures do not allow to meet all the requirements that a QNS implementation should satisfy, in particular scaling to a largenumber of users and coping with platform heterogeneity.QNS addresses both these problems through a layered architecture that (i) encapsulates the technological infrastructure speci.c of each organization, (ii) adopts the standardWeb-service technology to implement inter-organization communications, and (iii) embeds solutions and algorithms (namely, merge subscriptions and diffusion trees) to reduce the use of physical and computational resources.The remainder of this paper is organized as follows: we first introduce some preliminary concepts and the QNS specification (Section 2); then we motivate (Section 3) and describe (Section 4) the internal architecture of the service. Due to the lack of space, explanations are given at a very high abstraction level. Interested readers can find technical and formal details, as well as running examples, in [9].
Solving large-scale optimization problems with EFCOSS
Authors: Christian H. Bischof, H. Martin Bücker, Bruno Lang, Arno Rasch
Venue: Advances in Engineering Software (2003)

Derivatives play a prominent role in many areas of scientific computing. Traditionally, divided differences are employed to approximate derivatives, leading often to results of dubious quality at great computational expense. Automatic differentiation (AD), by contrast, is a powerful technique for accurately evaluating derivatives of functions described in a high-level programming language. AD requires little human effort and produces derivatives without truncation error. Although there is no conceptual difference between small and large codes, applying AD to programs with hundreds of thousands of lines of code is still a challenging task and requires a robust AD tool. We report on recent accomplishments of AD applied to the general-purpose finite element package SEPRAN transforming approximately 400,000 lines of Fortran77, and its integration into a prototype problem solving environment called EFCOSS supporting interoperability of simulation codes with optimization software using AD technology.
Simulated Annealing and Graph Colouring
Authors: Andreas Nolte, Rainer Schrader
Venue: Combinatorics, Probability and Computing (2001)

Simulated annealing is a very successful heuristic for various problems in combinatorial optimization. In this paper an application of simulated annealing to the 3-colouring problem is considered. In contrast to many good empirical results we will show for a certain class of graphs that the expected first hitting time of a proper colouring, given an arbitrary cooling scheme, is of exponential size.These results are complementary to those in [13], where we prove the convergence of simulated annealing to an optimal solution in exponential time.
An efficient and robust algorithm for 2D stratified fluid flow calculations
Authors: G. Larrazábal, C. R. Torres, J. Castillo
Venue: Applied Numerical Mathematics (2003)

An efficient and robust algorithm for numerical simulation of 2D stratified flow past an object is presented. The algorithm uses an accurate and efficient GMRES to solve the pressure. The algorithm is tested by simulating the flow past an infinite flat plate in uniform flow for various flow conditions. Results are presented for the density and velocity along with comparisons to the exact solution for this problem.
Rethinking competence systems for knowledge-based organizations
Authors: Rikard Lindgren, Dick Stenmark, Jan Ljungberg
Venue: European Journal of Information Systems (2003)

Existing competence systems are based on a rationalistic view of competence. While these competence systems might work in job-based organizations, we argue that in more dynamic settings, such as in knowledge-based organizations, the interest-informed actions that capture the emergent competencies of tomorrow require different types of information technology support. The main objective of this paper is to elaborate on the possibilities and implications of using interest-activated technology as a design rationale for competence systems. This paper is based on an action case study of an implemented interest-activated Intranet recommender system prototype at Volvo Information Technology AB in Gothenburg, Sweden. On the basis of how organizational members used this prototype to find information they were interested in, our research team was able to inquire into how personal interest, embodied in information-seeking activities, could be a means for identifying competence. Building on the relation between personal interest and competence, we discuss competence systems design and spell out explicit implications for managerial practice in knowledge-based organizations.
Java-MaC: A Run-Time Assurance Approach for Java Programs
Authors: Moonzoo Kim, Mahesh Viswanathan, Sampath Kannan, Insup Lee, Oleg Sokolsky
Venue: Formal Methods in System Design (2004)

We describe Java-MaC, a prototype implementation of the Monitoring and Checking (MaC) architecture for Java programs. The MaC architecture provides assurance that the target program is running correctly with respect to a formal requirements specification by monitoring and checking the execution of the target program at run-time. MaC bridges the gap between formal verification, which ensures the correctness of a design rather than an implementation, and testing, which does not provide formal guarantees about the correctness of the system.Use of formal requirement specifications in run-time monitoring and checking is the salient aspect of the MaC architecture. MaC is a lightweight formal method solution which works as a viable complement to the current heavyweight formal methods. In addition, analysis processes of the architecture including instrumentation of the target program, monitoring, and checking are performed fully automatically without human direction, which increases the accuracy of the analysis. Another important feature of the architecture is the clear separation between monitoring implementation-dependent low-level behaviors and checking high-level behaviors, which allows the reuse of a high-level requirement specification even when the target program implementation changes. Furthermore, this separation makes the architecture modular and allows the flexibility of incorporating third party tools into the architecture. The paper presents an overview of the MaC architecture and a prototype implementation Java-MaC.
WISDNA: An Information Visualization Paradigm for XML
Authors: Ricardo Baeza-Yates, Ricardo Lemus, Dulce Ponceleon, Savitha Srinivasan
Venue: Proceedings of the First Conference on Latin American Web Congress (2003)

With ever-increasing amounts of data in repositories, finding the information a user needsbecomes increasingly challenging. When users approach an information access system they often do not have a clear understanding of how to access the precise information they need. Additionally, it is not rare that users have only a vague notion of what they are looking for, hence the need for an exploratory navigation tool beyond a static list of search results. A model used in practice is an iterative search-and-browse cycle to retrieve relevant information. The role of the user interface in understanding search results and providing relevant metadata in a compact manner is a key component of this iterative process. In this context we present WISDNA as an information visualization paradigm for XML data from web information services.
A Generative Programming Framework for Adaptive Middleware
Authors: Venkita Subramonian, Christopher Gill
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 9 - Volume 9 (2004)

Component middleware technologies such as the CORBA Component Model (CCM) [1], J2EE [2], and .NET [3], were developed to address many limitations like interdependenciesbetween services and object interfaces, limited re-use, of first-generation middleware technologies such as CORBA 2.x [4], XML [5], and SOAP [6]. These component technologies have addressed a wide range of application domains, but unfortunately for distributed real-timeand embedded (DRE) systems, the focus of these technologies has been primarily on functional and not quality of service (QoS) properties. Research on QoS-aware component models such as the CIAO project [7, 8] shows that there is a fundamental difference between configuration of functional and QoS properties even within such a unified component model: the dominant decomposition of functional properties is essentially object-oriented, while the dominant decomposition of QoS properties is essentially aspect-oriented. In this paper, we describe how a focus on aspect frameworks for configuring QoS properties both complements and extends QoS-aware component models.This paper makes three main contributions to the state of the art in DRE systems middleware. First, it describes a simple but representative problem for configuring QoS aspectsthat cut across architectural layers, system and distribution boundaries, which motivates our focus on aspect frameworks. Second, it provides a formalization of that problem using first order logic - Infrastructure Configuration Logic - which both guides the design of aspect configuration infrastructure, and offers a way to connect these techniques with model-integrated computing [9] approaches to further reduce the programming burden on DRE system developers. Third, it describes alternative mechanisms to ensure correct configuration of the aspects involved, and notes the phases of the DRE system lifecycle at which each such configuration mechanism is most appropriate.
Improving perl application performance
Authors: Bruce W. Lowther
Venue: Linux Journal (2004)

Get the most performance improvement for the least work.
Examination and Processing of the Images of Biomedical Microobjects
Authors: G. M. Popova, V. N. Stepanov
Venue: Automation and Remote Control (2004)

Methods for segmentation of multi-type color images of microobjects and discrimination of their external contours and those of the internal components of their elements were proposed and analyzed. For the &ldquo;Morfolog&rdquo; system intended for microscopic diagnosis, the experimental results were presented.
A MutaSynth in parameter space: interactive composition through evolution
Authors: Palle Dahlstedt
Venue: Organised Sound (2001)

In this vision paper I will discuss a few questions concerning the use of generative processes in composition and automatic music creation. Why do I do it, and does it really work? I discuss the problems involved, focusing on the use of interactivity, and describe the use of interactive evolution as a way of introducing interactivity in composition. The installation MutaSynth is presented as an implementation of this idea.
Looking into the past: enhancing mobile publish/subscribe middleware
Authors: M. Cilia, L. Fiege, C. Haul, A. Zeidler, A. P. Buchmann
Venue: Proceedings of the 2nd international workshop on Distributed event-based systems (2003)

Publish/subscribe (pub/sub) middleware facilitates loosely coupled cooperation and fits well the needs of spontaneous, ad-hoc interaction. However, newly started mobile applications have to be bootstrapped to interpret the current flow of notifications correctly and commence normal operation. This problem is aggravated in mobile environments where disconnections and context changes occur frequently.In this paper, we propose two forms of subscriptions that allow consumers to subscribe to past events to improve the bootstrapping process. The first form uses logical mobility to harness possible client movements and subscribe in future locations to bootstrap virtual counterparts before the application needs the data. The second form is based on buffers and offers a way to integrate data repositories distributed in the network.
Who is liable for bugs and security flaws in software?
Authors: Michael A. Cusumano
Venue: Communications of the ACM (2004)

Attempting to determine fault and responsibility based on available evidence.
Circulant preconditioned WR-BVM methods for ODE systems
Authors: Xiao-Qing Jin, Vai-kuong Sin, Li-li Song
Venue: Journal of Computational and Applied Mathematics (2004)

We consider the solution of a system of ordinary differential equations (ODEs) by waveform relaxation (WR) iterations in conjunction with boundary value methods (BVMs). The WR method is a continuous-in-time analogue of the stationary method and it iterates with functions. In each WR iteration, we use BVMs to discretize systems of ODEs. BVMs are relatively new ODE solvers based on linear multistep formulae. In this paper, we discuss the use of the generalized minimal residual (GMRES) method with block-circulant-circulant-block preconditioners for solving the linear systems arising from the application of BVMs in each WR iteration. These preconditioners are effective in speeding up the convergence rate of the GMRES method. Numerical experiments are presented to illustrate the effectiveness of our methods.