ppxscal/embedding_network huggingface dataset:
The Offset Cube: A Three-Dimensional Multicomputer Network Topology Using Through-Wafer Optics
Authors: W. Stephen Lacy, José L. Cruz-Rivera, D. Scott Wills
Venue: IEEE Transactions on Parallel and Distributed Systems (1998)

Three-dimensional packaging technologies are critical for enabling ultra-compact, massively parallel processors (MPPs) for embedded applications. Through-wafer optical interconnect has been proposed as a useful technology for building ultra-compact MPPs since it provides a simplified mechanism for interconnecting stacked multichip substrates. This paper presents the offset cube, a new network topology designed to exploit the packaging benefits of through-wafer optical interconnect in ultra-compact MPP systems. We validate the offset cube's topological efficiency by developing deadlock-free adaptive routing protocols with modest virtual channel requirements (only two virtual channels per link needed for full adaptivity). A preliminary analysis of router complexity suggests these protocols can be efficiently implemented in hardware. We also present a 3D mesh embedding for the offset cube. Network simulations show the offset cube performs comparably to a bidirectional 3D mesh of equal size under uniform, hot-spot, and trace-driven traffic loads. While the offset cube is not proposed as a general replacement for the mesh topology, it leverages the benefits of through-wafer optical interconnect more effectively than a mesh by completely eliminating chip-to-chip wires for data signals. Hence, the offset cube is an effective topology for interconnecting ultra-compact MCM-level MPP systems.
Classroom Note: Note on the Optimal Intercept Time of Vessels to a Nonzero Range
Authors: Martin J. Gander
Venue: SIAM Review (1998)

There is an even simpler solution to the optimal intercept problem of vessels to a nonzero range.
Kolmogorov Random Graphs and the Incompressibility Method
Authors: Harry Buhrman, Ming Li, John Tromp, Paul Vitányi
Venue: SIAM Journal on Computing (1999)

We investigate topological, combinatorial, statistical, and enumeration properties of finite graphs with high Kolmogorov complexity (almost all graphs) using the novel incompressibility method. Example results are (i) the mean and variance of the number of (possibly overlapping) ordered labeled subgraphs of a labeled graph as a function of its randomness deficiency (how far it falls short of the maximum possible Kolmogorov complexity) and (ii) a new elementary proof for the number of unlabeled graphs.
&Pi;2 -- a generic proxy platform for wireless access and mobility in CORBA
Authors: Rainer Ruggaber, Jochen Seitz, Michael Knapp
Venue: Proceedings of the nineteenth annual ACM symposium on Principles of distributed computing (2000)

Distributed applications in a wireless environment often suffer from sudden connection losses. Furthermore, scarce bandwidth and high error rates may affect data transmission so that traditional Internet protocols like TCP show unwanted behaviour. However, one of today's most popular middleware architectures, namely the Common Object Request Broker Architecture CORBA, is built on top of TCP. Hence, its extension into the wireless and mobile environment has to be carefully designed. This paper introduces &Pgr;2, a proxy platform for CORBA-based applications in the mobile environment that copes with the mentioned problems. It can be transparently integrated into existing distributed systems without changes to clients or servers using a generic interface and dynamic type determination. Furthermore, this platform flexibly provides services for context- and location-aware applications, thus broadening the scope of the CORBA-based middleware.
Optimizing the Delivery of Radiation Therapy to Cancer Patients
Authors: David M. Shepard, Michael C. Ferris, Gustavo H. Olivera, T. Rockwell Mackie
Venue: SIAM Review (1999)

In the field of radiation therapy, much of the research is aimed at developing new and innovative techniques for treating cancer patients with radiation. In recent years, new treatment machines have been developed that provide a much greater degree of computer control than was available with the machines of previous generations. One innovation has been the development of an approach called "tomotherapy.'' Tomotherapy can be defined as computer-controlled rotational radiotherapy delivered using an intensity-modulated fan beam of radiation. The successful implementation of the new delivery techniques requires the development of a suitable approach for optimizing each patient's treatment plan. One of the challenges is to quantify optimality in radiation therapy. We have tested a variety of objective functions and constraints in pursuit of a formulation that performs well for a wide variety of disease sites. An additional challenge stems from the sizable amount of data and the large number of variables that are involved in each optimization. This paper presents several approaches to optimizing treatment plans in radiation therapy, and the advantages and disadvantages of a number of formulations are explored.
Testing for Function and Performance: Towards anIntegrated Processor Validation Methodology
Authors: Pradip Bose
Venue: Journal of Electronic Testing: Theory and Applications (2000)

Microprocessor design teams use a combination of simulation-based and formal verification techniques to validate the pre-silicon models prior to &ldquo;tape-out&rdquo; and chip fabrication. Pseudo-random test case generation to &ldquo;cover&rdquo; the architectural space is still relied upon as the principal means to identify design bugs. However, such methods are limited to functional bugs only. Detection and diagnosis of timing (performance) bugs at the architectural level is largely an expert job. Architects guide the performance team to run manually generated test cases to validate the design from a performance viewpoint. In this paper, we will review some of the new approaches being tried out to automate the generation of performance test cases. We will show how this can be done within the basic framework of current functional validation and testing of pre-silicon processor models. Three categories of &ldquo;reference&rdquo; specifications are used in determining the defect-free pipeline timing behavior associated with generated test cases: (a) axiomatic specifications of intrinsic machine latencies and bandwidths&semi; (b) proven analytical models for simple basic block and loop test cases&semi; and, (c) a stable reference behavioral/functional (pre-RTL) model of the processor under development. We report experimental results obtained in performance validation studies applied to real PowerPC&trade; processor development projects.
Symmetric bimanual interaction
Authors: Ravin Balakrishnan, Ken Hinckley
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

We present experimental work that explores the factors governing symmetric bimanual interaction in a two-handed task that requires the user to track a pair of targets, one target with each hand. A symmetric bimanual task is a two-handed task in which each hand is assigned an identical role. In this context, we explore three main experimental factors. We vary the distance between the pair of targets to track: as the targets become further apart, visual diversion increases, forcing the user to divide attention between the two targets. We also vary the demands of the task by using both a slow and a fast tracking speed. Finally, we explore visual integration of sub-tasks: in one condition, the two targets to track are connected by a line segment which visually links the targets, while in the other condition there is no connecting line. Our results indicate that all three experimental factors affect the degree of parallelism, which we quantify using a new metric of bimanual parallelism. However, differences in tracking error between the two hands are affected only by the visual integration factor.
A Behavioral Approach to the Pole Structure of One-Dimensional and Multidimensional Linear Systems
Authors: J. Wood, U. Oberst, E. Rogers, D. H. Owens
Venue: SIAM Journal on Control and Optimization (2000)

We use the tools of behavioral theory and commutative algebra to produce a new definition of a (finite) pole of a linear system. This definition agrees with the classical one and allows a direct dynamical interpretation. It also generalizes immediately to the case of a multidimensional (nD) system. We make a natural division of the poles into controllable and uncontrollable poles. When the behavior in question has latent variables, we make a further division into observable and unobservable poles. In the case of a one-dimensional (1D) state-space model, the uncontrollable and unobservable poles correspond, respectively, to the input and output decoupling zeros, whereas the observable controllable poles are the transmission poles.Most of these definitions can be interpreted dynamically in both the 1D and nD cases, and some can be connected to properties of kernel representations. We also examine the connections between poles, transfer matrices, and their left and right matrix fraction descriptions (MFDs). We find behavioral results which correspond to the concepts that a controllable system is precisely one with no input decoupling zeros and an observable system is precisely one with no output decoupling zeros. We produce a decomposition of a behavior as the sum of subbehaviors associated with various poles. This is related to the integral representation theorem, which describes every system trajectory as a sum of integrals of polynomial exponential trajectories.
Issues Related to Least-Squares Finite Element Methods for the Stokes Equations
Authors: Jennifer M. Deang, Max D. Gunzburger
Venue: SIAM Journal on Scientific Computing (1999)

Least-squares finite element methods have become increasingly popular for the approximate solution of first-order systems of partial differential equations. Here, after a brief review of some existing theories, a number of issues connected with the use of such methods for the velocity-vorticity-pressure formulation of the Stokes equations in two dimensions in realistic settings are studied through a series of computational experiments. Finite element spaces that are not covered by existing theories are considered; included in these are piecewise linear approximations for the velocity. Mixed boundary conditions, which are also not covered by existing theories, are also considered, as is enhancing mass conservation. Next, problems in nonconvex polygonal regions and the resulting nonsmooth solutions are considered with a view toward seeing how accuracy can be improved. A conclusion that can be drawn from this series of computational experiments is that the use of appropriate mesh-dependent weights in the least-squares functional almost always improves the accuracy of the approximations. Concluding remarks concerning three-dimensional problems, the nonlinear Navier--Stokes equations, and the conditioning of the discrete systems are provided.
An Architecture for Computing Zech's Logarithms in GF(2m)
Authors: Francisco M. Assis, C. E. Pedreira
Venue: IEEE Transactions on Computers (2000)

In this paper, a new method for calculation of Zech's logarithm in $GF(2^m)$ is presented. For a given element, the logarithm is calculated by bit operations performed on its binary representation. No look-up tables are used. The proposed method makes feasible the implementation of an universal-type device for finite field arithmetic.
Interlacing Inequalities and Cartan Subspaces of Classical Real Simple Lie Algebras
Authors: Tin-Yau Tam
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

The well-known interlacing inequalities are examined in the framework of classical real simple Lie algebras.
APPN connection networks
Authors: Jesper Nilausen
Venue: International Journal of Network Management (1997)

In this fourth article on managing APPN networks the concepts of Connection Networks are discussed. Connection Networks are not a new type of network with new networking protocols. Existing network types with the capabilities of any-to-any addressing are categorized as Connection Networks. &copy; 1997 John Wiley Sons, Ltd.
Bias boosting technique for a 1.9GHz class AB RF amplifier
Authors: Tirdad Sowlati, Sifen Luo
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

A bias boosting technique for a 3.2V, 1.9GHz Class AB RF amplifier designed in a 30GHz BiCMOS process is presented in this paper. In a Class AB amplifier, the average current drawn from the supply depends on the input signal level. As the output power increases so does the average currents in both the emitter and the base of the power transistor. The increased average current causes an increased voltage drop in the biasing circuitry and the ballast resistor. This reduces the conduction angle in the amplifier, pushing it deep into Class B and even Class C operation, reducing the maximum output power by 25%. To avoid the power reduction, the amplifier should have a larger bias which inevitably has a larger power dissipation at low output power levels. The proposed bias boosting circuitry dynamically increases the bias of the power transistor as the output power increases. The amplifier has less power dissipation at low power levels with an increased maximum output power.
IntraED - an intranet solution for EDucation
Authors: Jan Madej, Tadeusz Wilusz
Venue: ACM SIGCSE Bulletin (1999)

The IntraED concept has been developed in 1996 as a solution for the problem of shortage of financial resources for setting up necessary environment for introducing the intranet technology into instructional process at the Cracow University of Economics. The developed system has been intensively tested since that and supporting more courses every year. Therefore we would like to share the IntraED system concept as well as gained experience coming out from over two academic years of tests with everybody interested in setting up low cost intranet environment for educational purposes.
A novel program representation for interprocedural analysis
Authors: Gagan Agrawal, Shyamala Murthy, Chandrashekhar Garud
Venue: ACM SIGPLAN Notices (1999)

Interprocedural optimizations and transformations are increasingly being used in industrial and academic compilers, especially the compilers for high performance systems. Interprocedural analysis involves a natural trade-off between the accuracy and efficiency of the analysis, which is typically manifested in the choice of program representation. In this paper, we present a novel full program representation, which we believe is concise enough to keep the compilation costs reasonable, but is detailed enough for useful flow-sensitive optimizations. We report on our experience in developing two novel optimization frameworks using this representation. We have implemented this framework on top of the SUIF infrastructure. We present the comparison of the size of the call graph, Myer's supergraph, and our representation on a set of benchmark programs.
Selection algorithms for replicated Web servers
Authors: Mehmet Sayal, Yuri Breitbart, Peter Scheuermann, Radek Vingralek
Venue: ACM SIGMETRICS Performance Evaluation Review (1998)

Replication of documents on geographically distributed servers can improve both performance and reliability of the Web service. Server selection algorithms allow Web clients to select one of the replicated servers which is "close" to them and thereby minimize the response time of the Web service. Using client proxy server traces, we compare the effectiveness of several "proximity" metrics including the number of hops between the client and server, the ping round trip time and the HTTP request latency. Based on this analysis, we design two new algorithms for selection of replicated servers and compare their performance against other existing algorithms. We show that the new server selection algorithms improve the performance of other existing algorithms on the average by 55%. In addition, the new algorithms improve the performance of the existing non-replicated Web servers on average by 69%.
Component design of retargetable program analysis tools that reuse intermediate representations
Authors: James Hayes, William G. Griswold, Stuart Moskovics
Venue: Proceedings of the 22nd international conference on Software engineering (2000)

Interactive program analysis tools are often tailored to one particular representation of programs, making adaptation to a new language costly. One way to ease adaptability is to introduce an intermediate abstraction&mdash;an adaptation layer&mdash;between an existing language representation and the program analysis tool. This adaptation layer translates the tool's queries into queries on the particular representation.Our experiments with this approach on the StarTool program analysis tool resulted in low-cost retargets for C, Tcl/Tk, and Ada. Required adjustments to the approach, however, led to insights for improving a client's retargetability. First, retargeting was eased by having our tool import a tool-centric (i.e., client-centric) interface rather than a general-purpose, language-neutral representation interface. Second, our adaptation layer exports two interfaces, a representation interface supporting queries on the represented program and a language interface that the client queries to configure itself suitably for the given language. Straightforward object-oriented extensions enhance reuse and ease the development of multi-language tools.
Intensive Data Management in Parallel Systems: A Survey
Authors: M. F. Khan, Ray Paul, Ishfaq Ahmed, Arif Ghafoor
Venue: Distributed and Parallel Databases (1999)

In this paper we identify and discuss issues that are relevant to the design and usage of databases handling massive amounts of data in parallel environments. The issues that are tackled include the placement of the data in the memory, file systems, concurrent access to data, effects on query processing, and the implications of specific machine architectures. Since not all parameters are tractable in rigorous analysis, results of performance and bench-marking studies are highlighted for several systems.
Formalization of Workflows and Correctness Issues in the Presence of Concurrency
Authors: Ïsmaïlcem Budak Arpinar, Uğur Halici, Sena Arpinar, Asuman Doğaç
Venue: Distributed and Parallel Databases (1999)

In this paper, main components of a workflow system that are relevant to the correctness in the presence of concurrency are formalized based on set theory and graph theory. The formalization which constitutes the theoretical basis of the correctness criterion provided can be summarized as follows:-Activities of a workflow are represented through a notation based on set theory to make it possible to formalize the conceptual grouping of activities.-Control-flow is represented as a special graph based on this set definition, and it includes serial composition, parallel composition, conditional branching, and nesting of individual activities and conceptual activities themselves.-Data-flow is represented as a directed acyclic graph in conformance with the control-flow graph.The formalization of correctness of concurrently executing workflow instances is based on this framework by defining two categories of constraints on the workflow environment with which the workflow instances and their activities interact. These categories are:-Basic constraints that specify the correct states of a workflow environment.-Inter-activity constraints that define the semantic dependencies among activities such as an activity requiring the validity of a constraint that is set or verified by a preceding activity.Basic constraints graph and inter-activity constraints graph which are in conformance with the control-flow and data-flow graphs are then defined to represent these constraints. These graphs are used in formalizing the intervals among activities where an inter-activity constraint should be maintained and the intervals where a basic constraint remains invalid.A correctness criterion is defined for an interleaved execution of workflow instances using the constraints graphs. A concurrency control mechanism, namely Constraint Based Concurrency Control technique is developed based on the correctness criterion. The performance analysis shows the superiority of the proposed technique. Other possible approaches to the problem are also presented.
The Zark library of utility functions
Authors: Gary A. Bergquist
Venue: ACM SIGAPL APL Quote Quad (1998)

The primary appeal of APL has always been its productivity. You can develop and maintain computer applications faster with APL than with any other high-level programming language. APL has a number of distinct traits that contribute to this productivity advantage over other languages. However, language productivity is only one side of the programmer productivity triangle. The other two are programmer experience and utility software. The programmer with the most productive language, the most experience, and the best utility software will develop better code, and faster than the programmer who is deficient in any of these three areas. Experienced APL programmers generally score well in the first two areas, but poorly in the third, probably because APL obviates the perceived need for high quality utility software. Programmers in other languages do not have this luxury and so tend to develop and rely upon more extensive and higher quality utility software. Consequently, the productivity advantage of APL programmers over other programmers is not as significant as it can be. ZarkLib, the Zark Library of Utility Functions, is a scheme that attempts to remedy this problem. It is both an extensive collection of APL utility software and a motivational scheme. It guarantees its growth and maintenance by employing a "pyramid" scheme that motivates APL programmers to give until it hurts, and then give again.
Designing storage area networks: a practical reference for implementing Fibre Channel SANs
Authors: Tom Clark
Venue: Addison-Wesley Networking Basics Series (1999)

Storage Area Networks (SANs) powered by Fibre Channel technology far exceed the capabilities of traditional storage and throughput methods and are quickly becoming the solution of choice for organizations that require high-volume data handling capacity.Written for network developers, technical staff, IT consultants, administrators, and managers, Designing Storage Area Networks goes far beyond a straight description of Fibre Channel specifications and standards; it offers practical guidelines for implementing and utilizing SANs to solve the real-world needs of business networks.This concise design and implementation guide introduces Fibre Channel SAN technology and demonstrates exactly how it can be used to address specific application challenges--from server clustering to ISP hosting, server-free tape backup to full-motion video. With this book, you will learn how Fibre Channel works and how to organize Fibre Channel components into an effective, scalable design; and you will discover today's best methods for managing storage area networks and volumes, including new troubleshooting techniques.You will find coverage of such vital topics as: Fibre Channel layers Gigabit transport and gigabit interface converters (GBICs) Flow control Point-to-point topology Arbitrated Loops and Arbitrated Loop hubs Switching hubs Fabrics and fabric switches Host bus adapters Fibre Channel RAID and Fibre Channel JBODs Fibre Channel-to-SCSI bridges SAN management and problem isolation techniques Building extended SANsMost important, the book features detailed case studies that demonstrate how SANs can solve a number of commonly encountered business challenges, including LAN-free and server-free tape backup, server clustering, and disaster recovery. As an information systems professional, you must keep pace with this powerful new technology. This book will serve as your guide to understanding the implications of Fibre Channel SANs and successfully applying them to the needs of your organization. 0201615843B04062001