ppxscal/embedding_network huggingface dataset:
High-Performance Routing in Networks of Workstations with Irregular Topology
Authors: Federico Silla, José Duato
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

Networks of workstations are rapidly emerging as a cost-effective alternative to parallel computers. Switch-based interconnects with irregular topology allow the wiring flexibility, scalability, and incremental expansion capability required in this environment. However, the irregularity also makes routing and deadlock avoidance on such systems quite complicated. In current proposals, many messages are routed following nonminimal paths, increasing latency and wasting resources. In this paper, we propose two general methodologies for the design of adaptive routing algorithms for networks with irregular topology. Routing algorithms designed according to these methodologies allow messages to follow minimal paths in most cases, reducing message latency and increasing network throughput.As an example of application, we propose two adaptive routing algorithms for AN1 (previously known as Autonet). They can be implemented either by duplicating physical channels or by splitting each physical channel into two virtual channels. In the former case, the implementation does not require a new switch design. It only requires changing the routing tables and adding links in parallel with existing ones, taking advantage of spare switch ports. In the latter case, a new switch design is required, but the network topology is not changed. Evaluation results for several different topologies and message distributions show that the new routing algorithms are able to increase throughput for random traffic by a factor of up to 4 with respect to the original up$^{\ast}\!$/down$^{\ast}$ algorithm, also reducing latency significantly. For other message distributions, throughput is increased more than seven times. We also show that most of the improvement comes from the use of minimal routing.
On Foster's information storage and retrieval using AVL trees
Authors: K. C. Tan
Venue: Communications of the ACM (1972)

Foster [2] has proposed a method of constructing an AVL tree with depth (height) h and the number of items N being fixed and with the weighted sum of the items a maximum. The purpose of this note is to show that this method does not work in general.
A New Approach to Proving the Correctness of Multiprocess Programs
Authors: Leslie Lamport
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1979)

A new, nonassertional approach to proving multiprocess program correctness is described by proving the correctness of a new algorithm to solve the mutual exclusion problem. The algorithm is an improved version of the bakery algorithm. It is specified and proved correct without being decomposed into indivisible, atomic operations. This allows two different implementations for a conventional, nondistributed system. Moreover, the approach provides a sufficiently general specification of the algorithm to allow nontrivial implementations for a distributed system as well.
Query-biased web page summarisation: a task-oriented evaluation
Authors: Ryen White, Joemon M. Jose, Ian Ruthven
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

We present a system that offers a new way of assessing web document relevance and new approach to the web-based evaluation of such a system. Provisionally named WebDocSum, the system is a query-biased web page summariser that aims to provide an alternative to the short, irrelevant abstracts typical of many web search result lists. Based on an initial evaluation the system appears to be more useful in helping users gauge document relevance than the traditional ranked titles/abstracts approach.
Inserting an edge into a planar graph
Authors: Carsten Gutwenger, Petra Mutzel, René Weiskircher
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Computing a crossing minimum drawing of a given planar graph G augmented by an additional edge e in which all crossings involve e, has been a long standing open problem in graph drawing. Alternatively, the problem can be stated as finding a planar combinatorial embedding of a planar graph G in which the given edge e can be inserted with the minimum number of crossings. Many problems concerned with the optimization over the set of all combinatorial embeddings of a planar graph turned out to be NP-hard. Surprisingly, we found a conceptually simple linear time algorithm based on SPQR trees, which is able to find a crossing minimum solution.
Formal modeling of active network nodes using PVS
Authors: Cindy Kong, P. Alexander, Darryl Dieckman
Venue: Proceedings of the third workshop on Formal methods in software practice (2000)

Active Networks are a new type of networks where all elements are programmable. Active packets can contain fragments of code to be executed on intermediate nodes they pass through. Active nodes provide the necessary environment and resources for the packets to be processed. In giving the users the capability to program the network as they desire, there is an issue of security risks. This paper presents a formal model for an active node that can be used to specify and verify the correct operation of the node. The model is used to verify that scenarios where privacy of data is violated or functionality of a node is compromised never occur. The proposed model is generic to any type of active node and is written using the Prototype Verification System (PVS).
A method for finding the least squares estimate of the intersection point of two Helices in space
Authors: R. J. Royston, J. Gregory
Venue: Communications of the ACM (1966)

When the helical trajectories of two charged particles moving away from a common point in a magnetic field are reconstructed from measurements on the tracks, the reconstructed tracks are perturbed by measurement and other errors and do not, in general, intersect. A method is given for adjusting the reconstructed tracks in a least squares manner so that they do intersect.
An Efficient Method for a Class of Continuous Nonlinear Knapsack Problems
Authors: A. Melman, G. Rabinowitz
Venue: SIAM Review (2000)

We propose a globally convergent method for the numerical solution of a class of continuous nonlinear knapsack problems arising, e.g., in chemical production service facilities.
Timed circuits: a new paradigm for high-speed design
Authors: Chris J. Myers, Wendy Belluomini, Kip Kallpack, Eric Peskin, Hao Zheng
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

In order to continue to produce circuits of increasing speeds, designers must consider aggressive circuit design styles such as self-resetting or delayed-reset domino circuits used in IBM's gigahertz processor (GUTS) and asynchronous circuits used in Intel's RAPPID instruction length decoder. These new timed circuit styles, however, cannot be efficiently and accurately analyzed using traditional static timing analysis methods. This lack of efficient analysis tools is one of the reasons for the lack of mainstream acceptance of these design styles. This paper discusses several industrial timed circuits and gives an overview of our timed circuit design methodology.
On the optimization of performance of time-sharing systems by simulation
Authors: J. Blatny, S. R. Clark, T. A. Rourke
Venue: Communications of the ACM (1972)

A simulation model of a time-sharing system with a finite noncontiguous store and an infinite auxiliary store is used to study the variation of system parameters such as store size, number of jobs allowed to execute simultaneously, job-scheduling algorithm, etc. The effects of these variations on a measure of system performance is used to ascertain which of the parameters controllable by the job-scheduling algorithm, including the scheduling itself, require optimization, and which of the parameters not normally controllable by the scheduling algorithm have a marked effect on system performance. System performance is based upon the mean cost of delay to all jobs processed. It is shown that significant improvements in the measure of system performance can be obtained by using variable time-slice techniques and by selecting the optimum round-robin cycle time. It appears that these features would benefit from optimization whereas other parameters controllable by the scheduling algorithm affect system performance in a predictable manner and would not benefit from optimization. Features not normally under the control of the scheduling algorithm can also have a marked effect on the measure of performance; in particular, supervisor overheads, the size of the store, and the speed of the CPU. A comparison is made between the results of the simulation model and two analytical equations for quantum-oriented nonpreemptive time-sharing systems. The comparison is found to be very favorable.
Consumer difficulties with computerized transactions: an empirical investigation
Authors: T. D. Sterling
Venue: Communications of the ACM (1979)

The prevalence with which errors may be encountered by the end targets of a computerized process is assessed. How many and what type of errors occur? How easily are they corrected? What is the reaction of consumers to errors&mdash;to a failure to correct them? What can be learned by designers of large management packages from such data? Results show that with the present state of the art, approximately 40 percent of individuals (or households) having average contacts with different types of accounts experience one or more errors per year. Eighty percent relate to billing. Attempts to correct errors often turned out to be difficult and not always successful. There appears to be some conflict between computer-using organizations and their public. Also the role of poor management packages including poor software is indicated. While most management systems may be adequate, results of the survey raise concerns about the timeless and the number of designs of very large linked program packages (as EFT for instance).
A generic wrapper architecture for multi-processor SoC cosimulation and design
Authors: Sungjoo Yoo, Gabriela Nicolescu, Damien Lyonnard, Amer Baghdadi, Ahmed A. Jerraya
Venue: Proceedings of the ninth international symposium on Hardware/software codesign (2001)

In communication refinement with multiple communication protocols and abstraction levels, the system specification is described by heterogeneous components in terms of communication protocols and abstraction levels. To adapt each heterogeneous component to the other part of system, we present a generic wrapper architecture that can adapt different protocols or different abstraction levels, or both. In this paper, we give a detailed explanation of applying the generic wrapper architecture to mixed-level cosimulation. As preliminary experiments, we applied it to mixed-level cosimulation of an IS-95 CDMA cellular phone system.
Requirements for advanced programming systems for list processing
Authors: Daniel G. Bobrow
Venue: Communications of the ACM (1972)

List processing systems should be designed to facilitate production of large programs to manipulate large complex symbolic data stores. This paper presents an overview of a number of system features which the author feels are important to improve the productivity of programmers working in such domains. A systems view is taken, rather than focusing just on language features, since algorithms must be not only coded in a language form, but debugged, modified, made efficient, and run on data. Because of this general framework, the requirements specified are applicable to the design of advanced programming systems for a wide range of applications. Three aspects of programming systems are highlighted: good interactive facilities, programmable control structures, and sophisticated data communication mechanisms. Interactive features are described to facilitate program composition, entry, testing, debugging, editing, optimization, and packaging. Implementation of a generalized environment structure model specified would allow programming of various control regimes including multiprocesses, coroutines and backtracking. Alternative methods of procedure invocation required include invocation by pattern and by monitoring condition. The need for extended data forms, storage management, and extensibility are stressed, as is the duality of data retrieval and function evaluation. Syntax directed input and output of data would facilitate use of complex data stores.
About the Mod: Part 1
Authors: Dave Phillips
Venue: Linux Journal (2000)

An expansion and revision of material found in Linux Music & Sound
Two-Dimensional Gantt Charts and a Scheduling Algorithm of Lawler
Authors: Michel X. Goemans, David P. Williamson
Venue: SIAM Journal on Discrete Mathematics (2000)

In this note we give an alternate proof that a scheduling algorithm of Lawler [E. L. Lawler, Ann. Discrete Math., 2 (1978), pp. 75--90, E. L. Lawler and J. K. Lenstra, in Ordered Sets, I. Rival, ed., D. Reidel, 1982, pp. 655--675] finds the optimal solution for the scheduling problem $1 | prec | \sum_j w_j C_j$ when the precedence constraints are series-parallel. We do this by using a linear programming formulation of $1 | prec | \sum_j w_j C_j$ introduced by Queyranne and Wang. [ Math. Oper. Res., 16 (1991), pp. 1--20]. Queyranne and Wang proved that their formulation completely describes the scheduling polyhedron in the case of series-parallel constraints; a by-product of our proof of correctness of Lawler's algorithm is an alternate proof of this fact. In the course of our proof it is helpful to use what might be called two-dimensional (2D) Gantt charts. We think these may find independent use, and to illustrate this we show that some recent work in the area becomes transparent using 2D Gantt charts.
Representation results for defeasible logic
Authors: Grigoris Antoniou, David Billington, Guido Governatori, Michael J. Maher
Venue: ACM Transactions on Computational Logic (TOCL) (2001)

The importance of transformations and normal forms in logic programming, and generally in computer science, is well documented. This paper investigates transformations and normal forms in the context of Defeasible Logic, a simple but efficient formalism for nonmonotonic reasoning based on rules and priorities. The transformations described in this paper have two main benefits: on one hand they can be used as a theoretical tool that leads to a deeper understanding of the formalism, and on the other hand they have been used in the development of an efficient implementation of defeasible logic.
Cryptographic sealing for information secrecy and authentication
Authors: David K. Gifford
Venue: Communications of the ACM (1982)

A new protection mechanism is described that provides general primitives for protection and authentication. The mechanism is based on the idea of sealing an object with a key. Sealed objects are self-authenticating, and in the absence of an appropriate set of keys, only provide information about the size of their contents. New keys can be freely created at any time, and keys can also be derived from existing keys with operators that include Key-And and Key-Or. This flexibility allows the protection mechanism to implement common protection mechanisms such as capabilities, access control lists, and information flow control. The mechanism is enforced with a synthesis of conventional cryptography, public-key cryptography, and a threshold scheme.
Hensel construction of F(x, u1, ..., xl) l ≥ 2 at a singular point and its applications
Authors: Tateaki Sasaki, Daiju Inaba
Venue: ACM SIGSAM Bulletin (2000)

In 1993, Sasaki and Kako proposed a Hensel-like construction of F(x, u1,&iexcl;&shy;,ul),l &iexcl;&Yacute; 2, at a singular point where the conventional generalized Hensel construction breaks down. In this paper, we first extend Sasaki-Kako's method so as to apply to polynomials with vanishing leading coefficients. Then, we investigate a special case that the initial factors are polynomials. We prove that the multivariate polynomial can be decomposed at any singular point into factors which are polynomials in a main variable with coefficients being (infinite) series of rational functions such that &iexcl;&AElig;k=0&iexcl;&THORN;[N k(u1&iexcl;&shy;,ul)/ Dk(u1,&iexcl;&shy;,ul)]. Here, Nk and Dk are homogeneous polynomials in u1 - s1,&iexcl;&shy;,ul - sl and tdeg(Nk) - tdeg(Dk) = k, where (s1,&iexcl;&shy;,sl) is the expansion point and tdeg denotes the total-degree. The extended Hensel construction can be used to factorization of multivariate polynomials having a singular point at the origin. After performing the extended Hensel construction at the origin, we search for the smallest subsets of Hensel factors such that the product of the members of each subset contains no rational function. Then, we obtain the factorization in K{u1,&iexcl;&shy;,ul}[ x], with K a number field. Next, we search for the smallest subsets such that the product of the members of each subset contains no infinite series. Then, we obtain the factorization in K[x, u1,&iexcl;&shy;,ul], without employing the so-called nonzero substitution.
The impact and use of computer technology by the police
Authors: Kent W. Colton
Venue: Communications of the ACM (1979)

Over the past decade there has been a significant growth in the use of computer technology by U.S. police departments. This growth, however, has been at a slower rate than predicted in the early 1970's. Further, when computer applications extend beyond &ldquo;routine&rdquo; uses to &ldquo;nonroutine&rdquo; efforts, such as resource allocation or computer-aided-dispatch systems where the machine begins to become a tool for decision making, strategic planning and person/machine interaction, the results of the technology to date have been mixed. This paper reports on case studies and surveys which provide insights on the implementation and impact of police computer technology and the relationship of this technology to law enforcement and society.
The EAS-E application development system: principles and language summary
Authors: Harry M. Markowitz, Ashok Malhotra, Donald P. Pazel
Venue: Communications of the ACM (1984)

EAS-E is based on the entity-attribute-set view of system description&mdash;a useful formalism for system modeling and planning even when programming is done in languages other than EAS-E.
Model-Based Recognition of 3D Objects from Single Images
Authors: Isaac Weiss, Manjit Ray
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2001)

In this work, we treat major problems of object recognition which have received relatively little attention lately. Among them are the loss of depth information in the projection from a 3D object to a single 2D image, and the complexity of finding feature correspondences between images. We use geometric invariants to reduce the complexity of these problems. There are no geometric invariants of a projection from 3D to 2D. However, given certain modeling assumptions about the 3D object, such invariants can be found. The modeling assumptions can be either a particular model or a generic assumption about a class of models. Here, we use such assumptions for single-view recognition. We find algebraic relations between the invariants of a 3D model and those of its 2D image under general projective projection. These relations can be described geometrically as invariant models in a 3D invariant space, illuminated by invariant ¿light rays,¿ and projected onto an invariant version of the given image. We apply the method to real images.
Maximally Robust Controllers for Multivariable Systems
Authors: S. K. Gungah, G. D. Halikias, I. M. Jaimoukha
Venue: SIAM Journal on Control and Optimization (2000)

The set of all optimal controllers which maximize a robust stability radius for unstructured additive perturbations may be obtained using standard Hankel-norm approximation methods. These controllers guarantee robust stability for all perturbations which lie inside an open ball in the uncertainty space (say, of radius r 1). Necessary and sufficient conditions are obtained for a perturbation lying on the boundary of this ball to be destabilizing for all maximally robust controllers. It is thus shown that a "worst-case direction" exists along which all boundary perturbations are destabilizing. By imposing a parametric constraint such that the permissible perturbations cannot have a "projection" of magnitude larger than $(1-\delta ) r_1,\;0 subset of all maximally robust controllers can be extended beyond the ball of radius r1. The choice of the "best" maximally robust controller---in the sense that the uncertainty region guaranteed to be stabilized becomes as large as possible---is associated with the solution of a superoptimal approximation problem. Expressions for the improved stability radius are obtained and some interesting links with $\mu$-analysis are pursued.
I/O reference behavior of production database workloads and the TPC benchmarks&mdash;an analysis at the logical level
Authors: Windsor W. Hsu, Alan Jay Smith, Honesty C. Young
Venue: ACM Transactions on Database Systems (TODS) (2001)

As improvements in processor performance continue to far outpace improvements in storage performance, I/O is increasingly the bottleneck in computer systems, especially in large database systems that manage huge amoungs of data. The key to achieving good I/O performance is to thoroughly understand its characteristics. In this article we present a comprehensive analysis of the logical I/O reference behavior of the peak productiondatabase workloads from ten of the world's largest corporations. In particular, we focus on how these workloads respond to different techniques for caching, prefetching, and write buffering. Our findings include several broadly applicable rules of thumb that describe how effective the various I/O optimization techniques are for the production workloads. For instance, our results indicate that the buffer pool miss ratio tends to be related to the ratio of buffer pool size to data size by an inverse square root rule. A similar fourth root rule relates the write miss ratio and the ration of buffer pool size to data size. In addition, we characterize the reference characteristics of workloads similar to the Transaction Processing Performance Council (TPC) benchmarks C (TPC-C) and D(TPC-D), which are de facto standard performance measures for online transaction processing (OLTP) systems and decision support systems (DSS), respectively. Since benchmarks such as TPC-C and TPC-D can only be used effectively if their strengths and limitations are understood, a major focus of our analysis is to identify aspects of the benchmarks that stress the system differently than the production workloads. We discover that for the most part, the reference behavior of TPC-C and TPC-D fall within the range of behavior exhibited by the production workloads. However, there are some noteworthy exceptions that affect well-known I/O optimization techniques such as caching (LRU is further from the optimal for TPC-C, while there is little sharing of pages between transactions for TPC-D), prefetching (TPC-C exhibits no significant sequentiality), and write buffering (write buffering is lees effective for the TPC benchmarks). While the two TPC benchmarks generally complement one another in reflecting the characteristics of the production workloads, there remain aspects of the real workloads that are not represented by either of the benchmarks.