ppxscal/embedding_network huggingface dataset:
HLS: combining statistical and symbolic simulation to guide microprocessor designs
Authors: Mark Oskin, Frederic T. Chong, Matthew Farrens
Venue: ACM SIGARCH Computer Architecture News (2000)

As microprocessors continue to evolve, many optimizations reach a point of diminishing returns. We introduce HLS, a hybrid processor simulator which uses statistical models and symbolic execution to evaluate design alternatives. This simulation methodology allows for quick and accurate contour maps to be generated of the performance space spanned by design parameters. We validate the accuracy of HLS through correlation with existing cycle-by-cycle simulation techniques and current generation hardware. We demonstrate the power of HLS by exploring design spaces defined by two parameters: code properties and value prediction. These examples motivate how HLS can be used to set design goals and individual component performance targets. Additionally, these traces are not as susceptible to transient behavior because they are restricted to frequently executed code. Empirical results show that on average this mechanism can achieve better instruction fetch rates using only 12KB of hardware than a trace cache requiring 15KB of hardware, while producing long, persistent traces more suited to optimization.
Securing the global, remote, mobile user
Authors: Walt Curtis Lori Sinton
Venue: International Journal of Network Management (1999)

Electronic commerce is inevitable and will reshape our lives, but before true electronic commerce environments can be realized, it will be necessary to secure your enterprise against outside attacks on its electronic information and provide controls for authorized access to that information. Copyright &copy; 1999 John Wiley Sons, Ltd.
Interface and cache power exploration for core-based embedded system design
Authors: Tony D. Givargis, Jörg Henkel, Frank Vahid
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

Minimizing power consumption is of paramount importance during the design of embedded (mobile computing) systems that come as systems-on-a-chip, since interdependencies of design characteristics like power, performance, and area for various system parts (cores) become increasingly influential. In this scenario, interfaces play a key role since they allow one to control/exploit these interdependencies with the aim to meet design constraints like power. In this paper, we present the first comprehensive approach to explore this impact. We consider a whole system comprising a CPU, caches, a main memory and interfaces between those cores and demonstrate the high impact that an adequate adaptation between core parameters and interface parameters in terms of power consumption has. We especially found that cache parameters and bus configurations of cache buses have a significant impact in this respect. In addition, we made the important observation that optimizing for performance no longer implies that power is optimized as well in deep submicron technologies. Instead, we found out that especially for newer technologies, the relative interface power contribution increases, leading to scenarios where we obtain a real power/performance tradeoff. In summary, our explorations unveiled not yet investigated interdependencies that represent the first step towards future efforts to optimize/adapt interfaces and caches in core-based systems for low power designs.
Vector Median Filters, Inf-Sup Operations, and Coupled PDE's: Theoretical Connections
Authors: Vicent Caselles, Guillermo Sapiro, Do Hyun Chung
Venue: Journal of Mathematical Imaging and Vision (2000)

In this paper, we formally connect between vector median filters, inf-sup morphological operations, and geometric partial differential equations. Considering a lexicographic order, which permits to define an order between vectors in R^N, we first show that the vector median filter of a vector-valued image is equivalent to a collection of infimum-supremum morphological operations. We then proceed and study the asymptotic behavior of this filter. We also provide an interpretation of the infinitesimal iteration of this vectorial median filter in terms of systems of coupled geometric partial differential equations. The main component of the vector evolves according to curvature motion, while, intuitively, the others regularly deform their level-sets toward those of this main component. These results extend to the vector case classical connections between scalar median filters, mathematical morphology, and mean curvature motion.
A low power unified cache architecture providing power and performance flexibility (poster session)
Authors: Afzal Malik, Bill Moyer, Dan Cermak
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

Advances in technology have allowed portable electronic devices to become smaller and more complex, placing stringent power and performance requirements on the devices components. The M7CORE M3 architecture was developed specifically for these embedded applications. To address the growing need for longer battery life and higher performance, an 8-Kbyte, 4-way set-associative, unified (instruction and data) cache with pro-grammable features was added to the M3 core. These features allow the architecture to be optimized based on the applications requirements. In this paper, we focus on the features of the M340 cache sub-system and illustrate the effect on power and perfor-mance through benchmark analysis and actual silicon measure-ments.
Presenting to local and remote audiences: design and use of the TELEP system
Authors: Gavin Jancke, Jonathan Grudin, Anoop Gupta
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

The current generation of desktop computers and networks are bringing streaming audio and video into widespread use. A small investment allows presentations or lectures to be multicast, enabling passive viewing from offices or rooms. We surveyed experienced viewers of multicast presentations and designed a lightweight system that creates greater awareness in the presentation room of remote viewers and allows remote viewers to interact with each other and the speaker. We report on the design, use, and modification of the system, and discuss design tradeoffs.
Approximating multi-dimensional aggregate range queries over real attributes
Authors: Dimitrios Gunopulos, George Kollios, Vassilis J. Tsotras, Carlotta Domeniconi
Venue: ACM SIGMOD Record (2000)

Finding approximate answers to multi-dimensional range queries over real valued attributes has significant applications in data exploration and database query optimization. In this paper we consider the following problem: given a table of d attributes whose domain is the real numbers, and a query that specifies a range in each dimension, find a good approximation of the number of records in the table that satisfy the query. We present a new histogram technique that is designed to approximate the density of multi-dimensional datasets with real attributes. Our technique finds buckets of variable size, and allows the buckets to overlap. Overlapping buckets allow more efficient approximation of the density. The size of the cells is based on the local density of the data. This technique leads to a faster and more compact approximation of the data distribution. We also show how to generalize kernel density estimators, and how to apply them on the multi-dimensional query approximation problem. Finally, we compare the accuracy of the proposed techniques with existing techniques using real and synthetic datasets.
Design of high performance RAID in real-time system
Authors: Peng Cheng, Hai Jin, Jiangling Zhang
Venue: ACM SIGARCH Computer Architecture News (1999)

In this paper, we design a high performance RAID (Redundant Arrays of Independent Disks), called HUST_RAID, in real-time system. First, we give the architecture and the real-time process model of HUST_RAID. On the study of real-time disk I/O scheduling algorithm, we design a multiple queues real-time I/O scheduling algorithm. A new buffer management policy used in HUST_RAID is also given. It is the combination of some advanced technologies. We also introduce the design of software of the control system, which implements request receiving and decomposing, buffer management, data reconstruction, data rebuilding etc. A last, the performance of HUST_RAID is measured. From the testing results, the performance of HUST_RAID system is very excellent
Deductive database languages: problems and solutions
Authors: Mengchi Liu
Venue: ACM Computing Surveys (CSUR) (1999)

Deductive databases result from the integration of relational database and logic programming techniques. However, significant problems remain inherent in this simple synthesis from the language point of view. In this paper, we discuss these problems from four different aspects: complex values, object orientation, higher-orderness, and updates. In each case, we examine four typical languages that address the corresponding issues.
Lattice Polytopes Associated to Certain Demazure Modules of sln + 1
Authors: Raika Dehy, Rupert W. T. Yu
Venue: Journal of Algebraic Combinatorics: An International Journal (1999)

Let w be an element of the Weyl group of sl_n + 1. We prove that for a certain class of elements w (which includes the longest element w_0 of the Weyl group), there exist a lattice polytope &Delta; &sub; R^&ell;(w), for each fundamental weight &omega;_i of sl_n + 1, such that for any dominant weight &lambda; &equals; &sum;_i &equals; 1^n a_i &omega;_i, the number of lattice points in the Minkowski sum &Delta;_&lambda;^w &equals; &sum;_i &equals; 1^n a_i&Delta;_i^w is equal to the dimension of the Demazure module E(&lambda;). We also define a linear map A : R^&ell;(w) &rarr; P &otimes;_ZR where P denotes the weight lattice, such that char E(&lambda;) &equals; e^&lambda; &sum;e^&minus;A(x) where the sum runs through the lattice points x of &Delta;_&lambda;^w.
Multiple Comparisons in Induction Algorithms
Authors: David D. Jensen, Paul R. Cohen
Venue: Machine Learning (2000)

A single mechanism is responsible for three pathologies of induction algorithms: attribute selection errors, overfitting, and oversearching. In each pathology, induction algorithms compare multiple items based on scores from an evaluation function and select the item with the maximum score. We call this a multiple comparison procedure (MCP). We analyze the statistical properties of MCPs and show how failure to adjust for these properties leads to the pathologies. We also discuss approaches that can control pathological behavior, including Bonferroni adjustment, randomization testing, and cross-validation.
Teaching object-orientation with the Object Visualization and Annotation Language (OVAL)
Authors: Mirko Raner
Venue: ACM SIGCSE Bulletin (2000)

Object-oriented techniques and technologies are omnipresent in all branches of modern software development and systems design. Still today there is an enormous demand for training in the area of object-oriented analysis, design and programming.Several languages and notations have been developed for the visual presentation of object-oriented ideas and designs (eg, the Booch method [1], OMT [3] or the emerging standard UML [4]). Such languages or notations are an excellent means of communication and documentation amongst experts. However, for novice trainings they are not very suitable. Instead, they raise additional difficulties: not only a large number of new ideas and a new way of thinking has to be learned, but also a highly non-intuitive graphic notation to present these ideas.The newly developed Object Visualization and Annotation Language (OVAL) is a simple illustrative notation which aims at OO novices. It visualizes the key ideas of object-orientation in a very intuitive way and was especially designed to assist in the process of teaching the way of object-oriented thinking.
Optimal channel assignment strategies for forced channel hopping in CDPD systems
Authors: Chris Jedrzycki, Victor C. M. Leung
Venue: Mobile Networks and Applications (2000)

To provide an acceptable call blocking probability in circuit-switched cellular networks, such as the Advanced Mobile Phone System (AMPS) networks, a significant fraction of the channel capacity in each cell is normally unused. This &ldquo;free&rdquo; capacity can be effectively used for packet data transmissions that yield to voice traffic when necessary. Cellular Digital Packet Data (CDPD) is a packet-switched data service which may share radio channels with the AMPS service on a secondary basis to tap this &ldquo;free&rdquo; capacity. The length of time that a CDPD stream can occupy a channel is greatly influenced by the channel assignment strategies of both the AMPS and the CDPD systems. This paper investigates these channel assignment strategies and their effects on the CDPD channel holding times, in comparison with the optimal channel assignment strategy that interrupts the CDPD service only when a new AMPS call finds no other idle channels in the cell site. One such optimal strategy is the cooperative strategy in which the CDPD and AMPS networks actively communicate with each other. It is shown that other optimal strategies exist without the need of communications between the two systems. The effects of AMPS traffic levels, number of channels, and number of CDPD streams at the cell site on the CDPD channel holding time and channel utilization are also considered.
Feedback control of unsupported standing
Authors: K. J. Hunt, H. Golle, R. Jaime, N. Donaldson
Venue: Technology and Health Care (1999)

This paper presents the results of continuing work on feedback control of unsupported standing in paraplegia. Our experimental setup considers a situation in which all joints above the ankle are braced, and stabilising torque at the ankle is generated by stimulation of the plantarflexors. A previous study showed that short periods of unsupported standing with paraplegic subjects could be achieved. In order to improve consistency and reliability of unsupported standing we are currently investigating several modifications to the control strategy. The paper reports progress towards this goal.
A Penalized Neumann Control Approach for Solving an Optimal Dirichlet Control Problem for the Navier--Stokes Equations
Authors: L. S. Hou, S. S. Ravindran
Venue: SIAM Journal on Control and Optimization (1998)

We introduce a penalized Neumann boundary control approach for solving an optimal Dirichlet boundary control problem associated with the two- or three-dimensional steady-state Navier--Stokes equations. We prove the convergence of the solutions of the penalized Neumann control problem, the suboptimality of the limit, and the optimality of the limit under further restrictions on the data. We describe the numerical algorithm for solving the penalized Neumann control problem and report some numerical results.
Graphpak: a tool-builder's approach to graphical data presentation
Authors: Walt Niehoff
Venue: ACM SIGAPL APL Quote Quad (1998)

There have been several APL Quote Quad papers published in the past few years that discuss requirements for APL graphics capabilities. The Graphpak workspace now distributed with IBM's APL2 products evolved from its 1970 roots in an environment that projected similar requirements. This paper discusses the characteristics of Graphpak that have contributed to its evolving application and its longevity. Following an introduction that describes its evolution, the paper will focus on its "tool box" approach---using APL functions that can be used to build other functions to meet custom graphics requirements. Also, some opportunities for future exploitation of APL2 are sketched.
Exponentially Accurate Approximations to Periodic Lipschitz Functions Based on Fourier Series Partial Sums
Authors: Nana S. Banerjee, James F. Geer
Venue: Journal of Scientific Computing (1998)

The problem of accurately reconstructing a piecewise smooth. 2&pi;-periodic function f and its first few derivatives, given only a truncated Fourier series representation of f, is studied and solved. The reconstruction process is divided into two steps. In the first step, the first 2N + 1 Fourier coefficients of f are used to approximate the locations and magnitudes of the discontinuities in f and its first M derivatives. This is accomplished by first finding initial estimates of these quantities based on certain properties of Gibbs phenomenon, and then refining these estimates by fitting the asymptotic form of the Fourier coefficients to the given coefficients using a least-squares approach. The locations of the singularities are approximated to within O(N&minus;M&minus;2), and the associated jump of the kth derivative of f is approximated to within O(N&minus;M&minus;1+k), as N &rarr; &infin;, and the method is robust. These estimates are then used with a class of singular basis functions, which have certain &ldquo;built-in&rdquo; singularities, to construct a new sequence of approximations to f. Each of these new approximations is the sum of a piecewise smooth function and a new Fourier series partial sum. When N is proportional to M, it is shown that these new approximations, and their derivatives, converge exponentially in the maximum norm to f, and its corresponding derivatives, except in the union of a finite number of small open intervals containing the points of singularity of f. The total measure of these intervals decreases exponentially to zero as M &rarr; &infin;. The technique is illustrated with several examples.
The Fortran 90 bindings for OpenGL
Authors: William F. Mitchell
Venue: ACM SIGPLAN Fortran Forum (1999)

It is important to provide a good Fortran interface to OpenGL and related libraries for scientific visualization in mathematical software. OpenGL has had FORTRAN 77 bindings for some time, however these bindings rely upon several extensions to the FORTRAN 77 standard. By using the new features of Fortran 90 it is possible to define bindings for OpenGL that do not depend on any extensions to the standard and provide access to the full functionality of OpenGL.
The fault span of crash failures
Authors: George Varghese, Mahesh Jayaram
Venue: Journal of the ACM (JACM) (2000)

A crashing network protocol is an asynchronous protocol whose memory does not survive crashes. We show that a crashing network protocol that works over unreliable links can be driven to arbitrary global states, where each node is in a state reached in some (possibly different) execution, and each link has an arbitrary mixture of packets sent in (possibly different) executions. Our theorem considerably generalizes an earlier result, due to Fekete et al., which states that there is no correct crashing Data Link Protocol. For example, we prove that there is no correct crashing protocol for token passing and for many other resource allocation protocols such as k-exclusion, and the drinking and dining philosophers problems. We further characterize the reachable states caused by crash failures using reliable non-FIFO and reliable FIFO links. We show that with reliable non-FIFO links any acyclic subset of nodes and links can be driven to arbitrary states. We show that with reliable FIFO links, only nodes can be driven to arbitrary states. Overall, we show a strict hierarchy in terms of the set of states reachable by crash failures in the three link models.
A Stable Penalty Method for the Compressible Navier--Stokes Equations: III. Multidimensional Domain Decomposition Schemes
Authors: J. S. Hesthaven
Venue: SIAM Journal on Scientific Computing (1998)

This paper, concluding the trilogy, develops schemes for the stable solution of wave-dominated unsteady problems in general three-dimensional domains. The schemes utilize a spectral approximation in each subdomain and asymptotic stability of the semidiscrete schemes is established. The complex computational domains are constructed by using nonoverlapping quadrilaterals in the two-dimensional case and hexahedrals in the three-dimensional space. To illustrate the ideas underlying the multidomain method, a stable scheme for the solution of the three-dimensional linear advection-diffusion equation in general curvilinear coordinates is developed. The analysis suggests a novel, yet simple, stable treatment of geometric singularities like edges and vertices. The theoretical results are supported by a two-dimensional implementation of the scheme.The main part of the paper is devoted to the development of a spectral multidomain scheme for the compressible Navier--Stokes equations on conservation form and a unified approach for dealing with the open boundaries and subdomain boundaries is presented. Well posedness and asymptotic stability of the semidiscrete scheme is established in a general curvilinear volume, with special attention given to a hexahedral domain. The treatment includes a stable procedure for dealing with boundary conditions at a solid wall.The efficacy of the scheme for the compressible Navier--Stokes equations is illustrated by obtaining solutions to subsonic and supersonic boundary layer flows with various types of boundary conditions. The results are found to agree with the solution of the compressible boundary layer equations.
Tensor Methods for Large, Sparse Nonlinear Least Squares Problems
Authors: Ali Bouaricha, Robert B. Schnabel
Venue: SIAM Journal on Scientific Computing (1999)

This paper introduces tensor methods for solving large, sparse nonlinear least squares problems where the Jacobian either is analytically available or is computed by finite difference approximations. Tensor methods have been shown to have very good computational performance for small to medium-sized, dense nonlinear least squares problems. In this paper we consider the application of tensor methods to large, sparse nonlinear least squares problems where a sparse factorization of the Jacobian can be stored. This involves an entirely new way of solving the tensor model that is efficient for sparse problems. A number of interesting linear algebraic implementation issues are addressed. The test results of the tensor method applied to a set of sparse nonlinear least squares problems compared with those of the standard Gauss--Newton method reveal that the tensor method is significantly more robust and efficient than the standard Gauss--Newton method.
Distributed transactions in practice
Authors: Prabhu Ram, Lyman Do, Pamela Drew
Venue: ACM SIGMOD Record (1999)

The concept of transactions and its application has found wide and often indiscriminate usage. In large enterprises, the model for distributed database applications has moved away from the client-server model to a multi-tier model with large database application software forming the middle tier. The software philosophy of &ldquo;buy and not build&rdquo; in large enterprises has had a major influence by extending functional requirements such as transactions and data consistency throughout the multiple tiers. In this article, we will discuss the effects of applying traditional transaction management techniques to multi-tier architectures in distributed environments. We will show the performance costs associated with distributed transactions and discuss ways by which enterprises really manage their distributed data to circumvent this performance hit. Our intent is to share our experience as an industrial customer with the database research and vendor community to create more usable and scalable designs.
Didactic instructional tool for topics in computer science
Authors: Elena Trichina
Venue: ACM SIGCSE Bulletin (1999)

We consider the design of computer-enhanced teaching environment to be primarily a didactic task, and concentrate on representation of a domain structure and pedagogical view of the teaching process. At the core of our tutoring environment for computability topics is the ability of the system to engage students' previous knowledge of programming in comprehension of abstract concepts.