ppxscal/embedding_network huggingface dataset:
An experimental testbed for embedded real time Ada 95
Authors: W. M. Walker, P. T. Woolley, A. Burns
Venue: Proceedings of the ninth international workshop on Real-time Ada (1999)

The modifications made to Ada during the 9X process have resulted in a language that is ideally suited to programming real-time systems. In this paper we investigate the difficulties in realising this potential. In particular, we consider the issues raised when porting the public GNAT system on to a bare processor and producing a predictable and effective run-time system. As we were also concerned with issues of distribution via a CAN broadcast bus, support for the CAN protocol was included in the run-time system. In addition to investigating the performance of real-time Ada 95 applications we were also interested in more general issues associated with embedded kernel support for Ada 95. To facilitate these investigations and obtain the required level of performance, the thread package via which GNAT implement various aspects of the Ada language has been re-implemented. We discuss the architecture selected for this embedded kernel implementation and its relation to the architecture of the GNAT compiler.
Creating effective JavaHelp
Authors: Kevin Lewis
Venue:  (2000)

JavaHelp is an online help system developed in the Java programming language. Creating Effective JavaHelp covers the main features and options of JavaHelp and shows how to create a basic JavaHelp system, prepare help topics, and deploy the help system in an application. Written for all levels of Java developers and technical writers, the book takes a chapter-by-chapter approach to building concepts, to impart a complete understanding of how to create usable JavaHelp systems and integrate them into Java applications and applets.
A strategy for managing content complexity in algorithm animation
Authors: Linda Stern, Harald Søndergaard, Lee Naish
Venue: ACM SIGCSE Bulletin (1999)

Computer animation is an excellent medium for capturing the dynamic nature of data structure manipulations, and can be used to advantage in the teaching of algorithms and data structures. A major educational issue is the necessity of providing a means for the student to manage the complexity of the material. We have addressed this issue in a multimedia teaching tool called "Algorithms in Action" by allowing students to view an algorithm at varying levels of detail. Starting with a high level pseudocode description of the algorithm, with accompanying high level animation and textual explanation, students can expand sections of the pseudocode to expose more detail. Animation and explanation are controlled in a coordinated fashion, becoming correspondingly more detailed as the pseudocode is expanded. The tool also supports dofferem , pdes. corresponding to different stages in the learning process. Student feedback suggests that the availability of multiple levels detail and the facility for the user to control the level of detail being viewed is an effective way to manage content complexity.
Backward Perturbation Bounds for Linear Least Squares Problems
Authors: Ming Gu
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

Recently, Higham, Waldén, Karlson, and Sun have provided formulas for computing the best backward perturbation bounds for the linear least squares problem. In this paper we provide several backward perturbation bounds that are easier to compute and optimal up to a factor less than 2. We also show that any least squares algorithm that is stable in the sense of Stewart is necessarily a backward stable algorithm. Our results make it possible to measure numerically the amount of accuracy in any alleged solution of a least squares problem.
Traffic modeling and QoS prediction for MPEG-coded video services over ATM networks using scene level statistical characteristics
Authors: Sang-Jo Yoo, Seong-Dae Kim
Venue: Journal of High Speed Networks (2000)

In this paper, we propose a new traffic model and its queueing solution for MPEG-coded video sequences, which are now widely used for many types of video applications. The MPEG variable bit rate (VBR) video traffic has both very strong short-range correlations and long-range dependence. To capture the long-range dependence, we model the overall scene-level cell rate flow with a scene-level state transition diagram. At the same time, we use a frame-level chain to reflect the short-range correlation effects between the frames of the same frame type and between the different frame types within a scene state. Thus scene changes and frame sequences are modeled by a two-dimensional continuous time Markov chain. We provide an analytic queueing solution in terms of the maximum cell transfer delay and the cell loss ratio. The simulation results show that our analytical model accurately approximates the queueing performance of the original videos. Finally, with an asymptotic approximation, we provide a method for estimating the effective bandwidth for MPEG video sources with a guarantee of the users quality of service requirements.
The Conditioning of Boundary Element Equations on Locally Refined Meshes and Preconditioning by Diagonal Scaling
Authors: Mark Ainsworth, William McLean, Thanh Tran
Venue: SIAM Journal on Numerical Analysis (1999)

Consider a boundary integral operator on a bounded,d-dimensional surface in $\mbox{\smallBbb R}^{d+1}$. Suppose that the operator is a pseudodifferential operator of order $2m,$ $m\in\mbox{\smallBbb R},$ and that the associated bilinear form is symmetric and positive-definite. (The surface may be open or closed, and m may be positive or negative.) Let B denote the stiffness matrix arising from a Galerkin boundary element method with standard nodal basis functions. If local mesh refinement is used, then the partition may contain elements of very widely differing sizes, and consequently B may be very badly conditioned. In fact, if the elements are nondegenerate and 2|m|< d, then the $\ell_2$ condition number of B satisfies {\rm cond}({\mbox {\bf {\em B}}})\leq C N^{2|m|/d} \left(\frac{h_{\rm max}}{h_{\rm min}}\right)^{d-2m}, where hmax and h min are the sizes of the largest and smallest elements in the partition, and N is the number of degrees of freedom. However, if B is preconditioned using a simple diagonal scaling, then the condition number is reduced to ${\cal O}(N^{2|m|/d})$. That is, diagonal scaling restores the condition number of the linear system to the same order of growth as that for a uniform partition. The growth in the critical case 2|m|=d is worse by only a logarithmic factor.
Uniformly Accurate Finite Difference Schemes for p-Refinement
Authors: Lei Tang, James D. Baeder
Venue: SIAM Journal on Scientific Computing (1999)

The accuracy deficiency of high-order conventional finite difference schemes in the high-frequency range is attributed to the approximation property of a power polynomial interpolation over equispaced nodes. To improve the numerical representation of high-frequency solutions, a new family of high-order finite difference schemes is constructed by trigonometric polynomial interpolation. As expected, these new difference schemes can resolve a wider frequency range than conventional finite difference schemes with the same stencil. In particular, they remove the possibility of Runge's phenomenon for uniform mesh. The recently proposed optimized difference schemes are indeed types of mixed difference schemes which make a compromise between power and trigonometric polynomial interpolation.
Some Nonoverlapping Domain Decomposition Methods
Authors: Jinchao Xu, Jun Zou
Venue: SIAM Review (1998)

The purpose of this paper is to give a unified investigation of a class of nonoverlapping domain decomposition methods for solving second-order elliptic problems in two and three dimensions. The methods under scrutiny fall into two major categories: the substructuring--type methods and the Neumann--Neumann-type methods. The basic framework used for analysis is the parallel subspace correction method or additive Schwarz method, and other technical tools include local-global and global-local techniques. The analyses for both two- and three-dimensional cases are carried out simultaneously. Some internal relationships between various algorithms are observed and several new variants of the algorithms are also derived.
An optimality proof of the LRU-K page replacement algorithm
Authors: Elizabeth J. O'Neil, Patrick E. O'Neil, Gerhard Weikum
Venue: Journal of the ACM (JACM) (1999)

This paper analyzes a recently published algorithm for page replacement in hierarchical paged memory systems [O'Neil et al. 1993]. The algorithm is called the LRU-K method, and reduces to the well-known LRU (Least Recently Used) method for K = 1. Previous work [O'Neil et al. 1993; Weikum et al. 1994; Johnson and Shasha 1994] has shown the effectiveness for K > 1 by simulation, especially in the most common case of K = 2. The basic idea in LRU-K is to keep track of the times of the last K references to memory pages, and to use this statistical information to rank-order the pages as to their expected future behavior. Based on this the page replacement policy decision is made: which memory-resident page to replace when a newly accessed page must be read into memory. In the current paper, we prove, under the assumptions of the independent reference model, that LRU-K is optimal. Specifically we show: given the times of the (up to) K most recent references to each disk page, no other algorithm A making decisions to keep pages in a memory buffer holding n - 1 pages based on this infomation can improve on the expected number of I/Os to access pages over the LRU-K algorithm using a memory buffer holding n pages. The proof uses the Bayesian formula to relate the space of actual page probabilities of the model to the space of observable page numbers on which the replacement decision is acutally made.
Ill-Conditioned Matrices Are Componentwise Near to Singularity
Authors: Siegfried M. Rump
Venue: SIAM Review (1999)

For a square matrix normed to 1, the normwise distance to singularity is well known to be equal to the reciprocal of the condition number. In this paper we give an elementary and self-contained proof for the fact that an ill-conditioned matrix is also not far from a singular matrix in a componentwise sense. This is shown to be true for any weighting of the componentwise distance. In other words, for matrix inversion, "ill conditioned" means "nearly ill posed" in the normwise and also in the componentwise sense.
Controller Resynthesis for Testability Enhancement of RTLController/Data Path Circuits
Authors: Srivaths Ravi, Indradeep Ghosh, Rabindra K. Roy, Sujit Dey
Venue: Journal of Electronic Testing: Theory and Applications (1998)

In this paper, we propose a controller resynthesis technique to enhance the testability of register-transfer level (RTL) controller/data path circuits. Our technique exploits the fact that the control signals in an RTL implementation are don&lsquo;t cares under certain states/conditions. We make an effective use of the don&lsquo;t care information in the controller specification to improve the overall testability (better fault coverage and shorter test generation time). If the don&lsquo;t care information in the controller specification leaves little scope for respecification, we add control vectors to the controller to enhance the testability. Experimental results with example benchmarks show an average increase in testability of 9% with a 3&ndash;4 fold decrease in test generation time for the modified implementation. The area, delay and power overheads incurred for testability are very low. The average area overhead is 0.4%, and the average power overhead is 4.6%. There was no delay overhead due to this technique in most of the cases.
Microsoft TerraServer: a spatial data warehouse
Authors: Tom Barclay, Jim Gray, Don Slutz
Venue: ACM SIGMOD Record (2000)

Microsoft&reg; TerraServer stores aerial, satellite, and topographic images of the earth in a SQL database available via the Internet. It is the world's largest online atlas, combining eight terabytes of image data from the United States Geological Survey (USGS) and SPIN-2. Internet browsers provide intuitive spatial and text interfaces to the data. Users need no special hardware, software, or knowledge to locate and browse imagery. This paper describes how terabytes of &ldquo;Internet unfriendly&rdquo; geo-spatial images were scrubbed and edited into hundreds of millions of &ldquo;Internet friendly&rdquo; image tiles and loaded into a SQL data warehouse. All meta-data and imagery are stored in the SQL database. TerraServer demonstrates that general-purpose relational database technology can manage large scale image repositories, and shows that web browsers can be a good geo-spatial image presentation system.
Mechanical properties of human trabecular bone lamellae quantified by nanoindentation
Authors: P. K. Zysset, X. E. Guo, C. E. Hoffler, K. E. Moore, S. A. Goldstein
Venue: Technology and Health Care (1998)

The elastic modulus and hardness of embedded and rewet trabecular bone lamellae of the proximal femur have been quantified in four males and four females by nanoindentation. The average elastic moduli ranged from 6.9 to 15.9 GPa and were found to be significantly different among individuals. Hardness correlated with elastic modulus and followed similar trends.
OCR in a Hierarchical Feature Space
Authors: Jaehwa Park, Venu Govindaraju, Sargur N. Srihari
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

This paper describes a character recognition methodology (henceforth referred to as Hierarchical OCR) that achieves high speed and accuracy by using a multiresolution and hierarchical feature space. Features at different resolutions, from coarse to fine-grained, are implemented by means of a recursive classification scheme. Typically, recognizers have to balance the use of features at many resolutions (which yields a high accuracy), with the burden on computational resources in terms of storage space and processing time. We present in this paper, a method that adaptively determines the degree of resolution necessary in order to classify an input pattern. This leads to optimal use of computational resources. The Hierarchical OCR dynamically adapts to factors such as the quality of the input pattern, its intrinsic similarities and differences from patterns of other classes it is being compared against, and the processing time available. Furthermore, the finer resolution is accorded to only certain ¿zones¿ of the input pattern which are deemed important given the classes that are being discriminated. Experimental results support the methodology presented. When tested on standard NIST data sets, the Hierarchical OCR proves to be 300 times faster than a traditional K-nearest-neighbor classification method, and 10 times faster than a neural network method. The comparsion uses the same feature set for all methods. Recognition rate of about 96 percent is achieved by the Hierarchical OCR. This is at par with the other two traditional methods.
Spatial Queueing Processes
Authors: Wei Jing-Yuan, Yves Smeers, Xiaotao Huamg, Richard F. Serfozo
Venue: Mathematics of Operations Research (1999)

This study introduces a spatial queueing model for stochastic service systems in which customers or units move about and receive services in a region or a general space. The state of the system at any time is a point process that describes the numbers of units in subsets of the space, and the point process evolves over time as a Markov process. The system may be closed or open with a nite or unlimited capacity, and there may be multiple types of customers. The main result is a closed form expression for the stationary distribution of a spatial queueing process. Sufficient conditions are given for the process to be ergodic. Further results include formulas for throughputs, Little laws for average waiting times in sectors of the space, and necessary and sufficient conditions for various flows in open systems to be Poisson processes in time and space. Examples are given of systems with sector-dependent service rates, local-regional service rates, and multiclass customers. A large family of spatial systems are multi-class queueing networks in which the customer classes are nondiscrete marks or quantities (e.g., resources for services, temperature, physical characteristics) that affect services and routings.
A Systolic Image Difference Algorithm for RLE-Compressed Images
Authors: Fikret Ercal, Mark Allen, Hao Feng
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

A new systolic algorithm which computes image differences in run-length encoded (RLE) format is described. The binary image difference operation is commonly used in many image processing applications including automated inspection systems, character recognition, fingerprint analysis, and motion detection. The efficiency of these operations can be improved significantly with the availability of a fast systolic system that computes the image difference as described in this paper. It is shown that for images with a high similarity measure, the time complexity of the systolic algorithm is small and, in some cases, constant with respect to the image size. A formal proof of correctness for the algorithm is also given.
Semantic and pedagogic interoperability mechanisms in the ARIADNE educational repository
Authors: E. Forte, F. Haenni K. Warkentyne E. Duval K. Cardinaels E. Vervaet K. Hendrikx M. Wentland Forte F. Simillion
Venue: ACM SIGMOD Record (1999)

This paper reports on the principles underlying the semantic and pedagogic interoperability mechanisms built in the European Knowledge Pool System, developed by the European research project ARIADNE. This system, which is the central feature of ARIADNE, consists in a distributed repository of pedagogical documents (or learning objects) of diverse granularity, origin, content, type, language, etc., which are stored in view of their use (and reuse) in telematics-based training or teaching curricula. The learning objects are indexed, usually by faculty staff, according to the ARIADNE metadata set. The principles embodied in the indexation tool, which interacts directly with the repository,stem from a few theoretical ideas but foremost from empirical, pragmatic considerations, suggested by the context of actual use. They tentatively address the stringent demands for semantic and pedagogic interoperability implied by a context of rather wide cultural and linguistic diversity, as well as those stemming from the very nature of the domain application itself: education and training. Possible extensions to the educational metadata scheme developed by ARIADNE on these basis, may accommodate corporate training/information needs. These extensions are briefly discussed as a mean for enhancing 'semantic' interoperability between different (kinds of) corporations. Finally, the architecture of the ARIADNE system, which heavily relies on this educational metadata system, is briefly reviewed.
Maps: a compiler-managed memory system for raw machines
Authors: Rajeev Barua, Walter Lee, Saman Amarasinghe, Anant Agarwal
Venue: ACM SIGARCH Computer Architecture News (1999)

This paper describes Maps, a compiler managed memory system for Raw architectures. Traditional processors for sequential programs maintain the abstraction of a unified memory by using a single centralized memory system. This implementation leads to the infamous "Von Neumann bottleneck," with machine performance limited by the large memory latency and limited memory bandwidth. A Raw architecture addresses this problem by taking advantage of the rapidly increasing transistor budget to move much of its memory on chip. To remove the bottleneck and complexity associated with centralized memory, Raw distributes the memory with its processing elements. Unified memory semantics are implemented jointly by the hardware and the compiler. The hardware provides a clean compiler interface to its two inter-tile interconnects: a fast, statically schedulable network and a traditional dynamic network. Maps then uses these communication mechanisms to orchestrate the memory accesses for low latency and parallelism while enforcing proper dependence. It optimizes for speed in two ways: by finding accesses that can be scheduled on the static interconnect through static promotion, and by minimizing dependence sequentialization for the remaining accesses. Static promotion is performed using equivalence class unification and modulo unrolling; memory dependences are enforced through explicit synchronization and software serial ordering. We have implemented Maps based on the SUIF infrastructure. This paper demonstrates that the exclusive use of static promotion yields roughly 20-fold speedup on 32 tiles for our regular applications and about 5-fold speedup on 16 or more tiles for our irregular applications. The paper also shows that selective use of dynamic accesses can be a useful complement to the mostly static memory system.
Nonsymmetric Algebraic Riccati Equations and Hamiltonian-like Matrices
Authors: Jonq Juang, Wen-Wei Lin
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

We consider a nonsymmetric algebraic matrix Riccati equation arising from transport theory. The nonnegative solutions of the equation can be explicitly constructed via the inversion formula of a Cauchy matrix. An error analysis and numerical results are given. We also show a comparison theorem of the nonnegative solutions.
Measuring the Performance of Real-Time Systems
Authors: Wolfgang A. Halang, Roman Gumzej, Matjaz Colnaric, Marjan Druzovec
Venue: Real-Time Systems (2000)

So far, performance measures for real time systems did not receive much attention. An assessment of the few existing benchmarking methods for real time systems will reveal that they are highly inappropriate. Taking a closer look into the fundamental issues of real time systems it will become clear, that for hard real time systems qualitative characteristics are much more important than quantitative measures. The major qualitative performance criteria are compiled. Systems fulfiling the qualitative aspects may then be compared on the basis of costs.
A Globally and Superlinearly Convergent Gauss--Newton-Based BFGS Method for Symmetric Nonlinear Equations
Authors: Donghui Li, Masao Fukushima
Venue: SIAM Journal on Numerical Analysis (1999)

In this paper, we present a Gauss--Newton-based BFGS method for solving symmetric nonlinear equations which contain, as a special case, an unconstrained optimization problem, a saddle point problem, and an equality constrained optimization problem. A suitable line search is proposed with which the presented BFGS method exhibits an approximate norm descent property. Under appropriate conditions, global convergence and superlinear convergence of the method are established. The numerical results show that the proposed method is successful.
An introduction to data warehousing: what are the implications for the network?
Authors: Katherine Jones
Venue: International Journal of Network Management (1998)

Data warehousing is an information systems environment, rather than a product. It has emerged as an essential business entity for sophisticated analysis of data. This article presents a clear overview of the implications of data warehousing for business. &copy; 1998 John Wiley & Sons, Ltd.