ppxscal/embedding_network huggingface dataset:
Teaching Archetypal Design with an Electronic Textbook
Authors: Adam Rifkin
Venue:  (1993)

How can parallel programming be made tractable for students in high schools and community colleges, to programmers in four-year colleges, to commercial and government employees, to interested independent users learning on their own, and as CASE tools for professional software designers? The computer science community must address this question if the ability of programmers to harness the power of parallel systems is to maintain pace with technology advances forthcoming in parallel systems. This paper addresses some of the issues of bringing parallel programming to the people, ranging from newly developing programmers with little experience on any computer to seasoned programmers of single-processor machines. We aim not only to enable people to use more powerful computers, but also to enable people to use computers more powerfully, by nurturing the techniques that enable them to develop efficient, correct code with relative ease. This paper briefly presents the concept of an Archetype, a software engineering methodology developed at the Caltech for patterns of problem solving, and for providing media for quick reference and natural software reuse. We then describe eText, an interactive multimedia electronic textbook that facilitates the teaching of, navigating through, and referring to Archetypes. Initial experience with Archetypes and the electronic textbook suggests that this approach to teaching parallel programming can aid computer users in the immediate future.
Unreliable Failure Detectors for Asynchronous Distributed Systems
Authors: Tushar D Chandra
Venue:  (1993)

It is well-known that several fundamental problems of fault-tolerant distributed computing, such as Consensus and Atomic Broadcast, cannot be solved in asynchronous systems with crash failures. These impossibility results stem from the lack of reliable failure detection in such systems. To circumvent such impossibility results, we introduce the concept of unreliable failure detectors that can make mistakes, and study the problem of using them to solve Consensus (and Atomic Broadcast). It is easy to solve Consensus using a ``perfect'''' failure detector (one that does not make mistakes). But is perfect failure detection necessary to solve Consensus? We show that Consensus is solvable with unreliable failure detectors, even if they make an infinite number of mistakes. This leads to the following question: What is the ``weakest'''' failure detector for solving Consensus? We introduce a notion of algorithmic reducibility that allows us to compare seemingly incomparable failure detectors. Using this concept, we show that one of the failure detectors that we introduce here is indeed the weakest failure detector for solving Consensus in asynchronous systems with a majority of correct processes. We also show that Consensus and Atomic Broadcast are equivalent in asynchronous systems. Thus all our results regarding the solvability of Consensus using failure detectors, apply to Atomic Broadcast as well. The work in this thesis was funded by an IBM graduate fellowship and grants from NSF, DARPA/NASA, the IBM Endicott Programming Laboratory, Siemens Corp. and the Natural Sciences and Engineering Research Council of Canada.
Multithreading to Improve Cycle Width and CPI in Superpipelined Superscalar Processors
Venue: Proceedings of the 1996 International Symposium on Parallel Architectures, Algorithms and Networks (1996)

This paper presents a multithreaded superpipelined superscalar processor design. It is expected to have a sustained rate of 5.4 instructions run per cycle, with 4 threads on chip. Multithreading serves to improve the superscalar CPI by interleaving threads executions. Operator sharing is used instead of out of order execution. It requires less hardware -no reservation stations, collision vectors or renamed registers- and should offer a greater parallelism potential. Arithmetic operators, including adders, shifters, a multiplier and a step divider, have been pipelined to reduce the processor cycle width to a 16 bits adder propagation delay. Separate and equal lengths data paths controlled by a completely RISC instruction set allow efficient in order issue and termination. Floating point operations are emulated with integer ones with data dependent algorithms providing as good latencies as for traditional hardware implementation. A single register file serves for both the integer and the floating point data.
Improving Wireless Quality of Service by Using Different Strategies and Scheduler
Authors: Xiuli Ren, Guixing Luan
Venue: Proceedings of the 2001 International Conference on Computer Networks and Mobile Computing (ICCNMC'01) (2001)

Wireless network gradually develop based on wired network. It overcomes some defects which wired networks need layout ,its line do easily damage and stations can't move and it is difficulty to be connected with long-distance stations and so on. But, wireless links can exhibit high error rates due to attenuation ,fading, or interfering active radiation sources. To make matter worse, error rates can be highly variable due to changes in the wireless environment. According to all categories of traffic ,we present two error control schemes (i.e. ARQ and FEC) which are used to improve transport performance over the wireless link, and a mechanism (MPFQ scheduler ) to provide Quality of Service. Finally, we propose a Scheduler_Packet model for weighted fair queuing algorithm by adjusting flow weights in order to create outcome fairness.
Post-Route Gate Sizing for Crosstalk Noise Reduction
Authors: Murat R. Becer, David Blaauw, Ilan Algor, Rajendran Panda, Chanhee Oh, Vladimir Zolotov, Ibrahim N. Hajj
Venue: Proceedings of the 4th International Symposium on Quality Electronic Design (2003)

Gate sizing is a practical and a feasible crosstalk noisecorrection technique in the post route design stage, especiallyfor block level sea-of-gates designs. The difficulty ingate sizing for noise reduction is that by increasing a driversize, noise at the driver output is reduced, but noise injectedby that driver on other nets is increased. This can createcyclical dependencies between nets in the circuit with noiseviolations. In this paper, we propose a fast and effectiveheuristic post-route gate sizing algorithm that uses a graphrepresentation of the noise dependencies between nodes. Ourmethod utilizes gate sizing in both directions and works inlinear time as a function of the number of gates. The effectivenessof the algorithm is shown on several high performancedesigns.
The Digital Photographer's Guide to Photoshop Elements: Improve Your Photographs & Create Fantastic Special Effects
Authors: Barry Beckham, Peter Cope
Venue:  (2003)

:Adobe's Photoshop Elements 2.0 comes prepackaged with most amateur digital cameras on today's market--it's simply one of the most popular software programs for image editing. Access its power and master its possibilities with this photographer's companion. Featuring hundreds of images and 10 hands-on projects, the guide walks digital camera enthusiasts through all the ins and outs of the hardware and software, including cameras and computers; storage options; and printers and scanners. With it, you can learn about image film formats and how to save pictures for print or publishing on the Web; transform good photos into great ones with cropping techniques; rotate, flip, or resize photos to improve composition and quality; and simulate traditional darkroom procedures. There's a spotlight on panoramas using the Photomerge tool set; adding grain to a shot; and creating soft focus photos. The projects section shows how to use multiple techniques to make a single, specific image. If you've got a digital camera, and you own Photoshop Elements, you won't want to work without this.
Magic twin body stars generated from chains of prismoids
Authors: Hermann Mierendorff
Venue: Discrete Mathematics (2003)

There is a vertex-labeling with different integers for the compound or two tetrahedra such that the values on an edge always deliver the same magic sum. We investigate stars composed of a polyhedron and its dual where the generating polyhedron consists of a chain of w-sided prismoids. Let the resulting 3-uniform hypergraph show h latitudinal rings of points including the poles. Then a magic vertex-labeling exists if h = w + 1. Supermagic labeling is excluded. Examples up to w = 6 are presented.
Simple, Efficient Object Encoding using Intersection Types
Authors: Karl Crary
Venue:  (1998)

I present a type-theoretic encoding of objects that interprets method dispatch by self-application (i.e., method functions are applied to the objects containing them) but still validates the expected subtyping relationships. The naive typing of self-application fails to validate the expected subtyping relationships because it is too permissive and allows application to similarly typed objects that are not self. This new encoding solves this problem by constraining methods to be applied only to self using existential and intersection types. Using this typing, I give a full account of objects including self types and method update. I also present another application of this object encoding to fully abstract, closure-passing closure conversion. The typing constructs used in this encoding appear to be quite rich, but they may be axiomatized in a novel, restricted fashion that is metatheoretically simple.
The average dimension of the hull of cyclic codes
Authors: Gintaras Skersys
Venue: Discrete Applied Mathematics (2003)

We study Eq(n), the average dimension of the hull of error-correcting block cyclic codes of a given length n over a given finite field Fq, where the hull of a code is its intersection with its dual code. We derive an expression of Eq(n) which handles well. Using this expression, we prove that either Eq(n) is zero (if, and only if, n ∈ Nq), or it grows at the same rate as n, when n ∉ Nq, where Nq is the set of positive divisors of the integers of the form qi + 1, i > 0. This permits us to show that, for almost all n, the hull of most cyclic codes of length n is "large". Moreover, we study the asymptotic behaviour of Eq(n)/n as n tends to infinity.
Flash Cartoon Animation: Learn from the Pros, 1 edition
Venue:  (2002)

:You'll follow the actual professional process, taking an idea from script to final published film, via storyboard, art direction, and layout. Kevin and Glenn explain the fundamental theories of animation, with humor and plenty of examples, then show you how to take these principles and put them to work in Flash. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
High-level algorithmic complexity evaluation for system design
Authors: Massimo Ravasi, Marco Mattavelli
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2003)

The increasing complexity of processing algorithms has led to the need of more and more intensive specification and validation by means of software implementations. As the complexity grows, the intuitive understanding of the specific processing needs becomes harder and harder. Hence, the architectural implementation choices or the choices between different possible software/hardware partitioning become extremely difficult tasks. Moreover, it is also desirable to understand and measure the algorithm complexity at the highest possible level near to the algorithmic level so as to be able to take the more appropriate actions. Automatic tools to perform such analysis become nowadays a fundamental need.In this paper, the requirements of a suitable algorithmic complexity evaluation technology are discussed, with a particular emphasis to the problem of the analysis of multimedia systems and signal processing algorithms. A brief review about limitations and weaknesses of existing tools is given, specifying the characteristics of ideal "complexity evaluation systems". A new approach is described, called here Software Instrumentation Tool, SIT, yielding an automatic software tool able to extract information not depending on the simulation platform, keeping into account specific input data and resulting in a good and useful measure of the desired high-level algorithmic complexity.
Best approximation by linear combinations of characteristic functions of half-spaces
Authors: Paul C. Kainen, Věra Kůrková, Andrew Vogt
Venue: Journal of Approximation Theory (2003)

It is shown that for any positive integer n and any function f in Lp([0,1]d) with p ∈ [1,∞) there exist n half-spaces such that f has a best approximation by a linear combination of their characteristic functions. Further, any sequence of linear combinations of n half-space characteristic functions converging in distance to the best approximation distance has a subsequence converging to a best approximation, i.e., the set of such n-fold linear combinations is an approximatively compact set.
The concept of asynchronization
Authors: H. Wettstein, G. Merbeth
Venue: ACM SIGOPS Operating Systems Review (1980)

Communication between parallel processes may take place in synchronous or asynchronous form. The former has widely been used in various concepts. In contrast, means for asynchronous process relations exist only in a few systems in rudimentary form. In this paper the concept of asynchronization is developed systematically. The underlying data structures as well as operations upon them are defined for various versions.
Alternative correctness criteria for multiversion concurrency control and a locking protocol via freezing
Authors: Chanjung Park, Seog Park
Venue: Proceedings of the 1997 International Symposium on Database Engineering & Applications (1997)

Concurrency control protocols based on multiversions have been used in some commercial transaction processing systems in order to provide the serializable executions of transactions. In the existing protocols, transactions are allowed to read only the most recent version of each data item in order to ensure the correct execution of transactions. However this feature is not desirable in some advanced database systems which have more requirements such as timing or security constraints besides serializability. We propose a new correctness criteria, called F-serializability, for multiversion concurrency control protocols. It is the extended definition of 'l-serial' and relaxes the condition so that a protocol provides not only the most recent version but also the previous one to transactions, if necessary. We prove that whenever a multiversion schedule is F-serializable, the schedule is also one-copy serializable. This is the first contribution of our paper. Next, we propose a new concurrency control protocol for multilevel secure (MLS) database systems which guarantees the proposed serializability. In an MLS database system, a transaction scheduler must satisfy security constraints as well as ensure the serializable execution of transactions.
Computations, Residuals, and the Power of Indeterminacy
Authors: Prakash Panangaden, Eugene W. Stark
Venue:  (1987)

We investigate the power of Kahn-style dataflow networks, with processes that may exhibit indeterminate behavior. Our main result is a theorem about networks of ``monotone'''' processes, which shows: (1) that the input/output relation of such a network is a total and monotone relation; and (2) every relation that is total, monotone, and continuous in a certain sense, is the input/output relation of such a network. Now, the class of monotone networks includes networks that compute arbitrary continuous input/output functions, an ``angelic merge'''' network, and an ``infinity-fair merge'''' network that exhibits countably indeterminate branching. Since the ``fair merge'''' relation is neither monotone nor continuous, a corollary of our main result is the impossibility of implementing fair merge in terms of continuous functions, angelic merge, and infinity-fair merge. Our results are established by applying the powerful technique of ``residuals'''' to the computations of a network. Residuals, which have previously been used to investigate optimal reduction strategies for the $\lambda$-calculus, have recently been demonstrated by one of the authors (Stark) also to be of use in reasoning about concurrent systems. Here, we define the general notion of a ``residual operation'''' on an automaton, and show how residual operations defined on the components of a network induce a certain preorder $\extend$ on the set of computations of the network. For networks of ``monotone port automata,'''' we show that the ``fair'''' computations coincide with $\extend$-maximal computations. Our results follow from this extremely convenient property.
Evaluation of the Performance of Multithreaded Cilk Runtime System on SMP Clusters
Authors: Liang Peng, Mingdong Feng, Chung-Kwong Yuen
Venue: Proceedings of the 1st IEEE Computer Society International Workshop on Cluster Computing (1999)

Multithreading is widely accepted in shared memory system such as the symmetric multiprocessor (SMP) machine. However, in the clustering environment, multithreading is considered expensive and difficult. Process is still used as the basic scheduling unit in the majority of parallel programming systems on clusters. To investigate the overhead a runtime system may have in supporting multithreading, an extended multithreaded Cilk runtime system, called distributed Cilk, was evaluated on a cluster of SMP PCs. The distributed Cilk embodies the algorithmic features of the Cilk language, supports software distributed shared memory (DSM) for all Cilk threads in the cluster, and provides user-level cluster-wide locking. The performance of the distributed Cilk was evaluated using three problems, which were parallelized with different strategies to represent various parallel programming paradigms. The results were also compared with those of TreadMarks, a typical software DSM implementation for clusters with no support for multithreading. The experiments show that multithreading Cilk programs written in a divide-and-conquer fashion with good data locality can achieve comparable performance with the corresponding multiple-process TreadMarks programs. The results shed light on efficient multithreading for clusters.
A mugwump's-eye view of Web work
Authors: Robert L. Glass
Venue: Communications of the ACM (2003)

Choosing a point of entry into a contemporary software development debate.
TENEX: a paged time sharing system for the PDP-10
Authors: Daniel G. Bobrow, Jerry D. Burchfiel, Daniel L. Murphy, Raymond S. Tomlinson
Venue: ACM SIGOPS Operating Systems Review (1972)

TENEX is a new time sharing system implemented on a DEC PDP-10 augmented by special paging hardware developed at BBN. This report specified a set of goals which are important for any time sharing system. It describes how the TENEX design and implementation achieve these goals. These include specifications for a powerful multiprocess large memory virtual machine, intimate terminal interaction, comprehensive uniform file and I/O capabilities, and clean flexible system structure. Although the implementation described here required some compromise to achieve a system operational within six months of hardware checkout, TENEX has met its major goals and provided reliable service at several sites and through the ARPA network.
ETRDL Submit User Guide
Authors: Antonella Andreoni, Carlo Carlesi, Pasquale Pagano
Venue:  (1999)

The ERCIM Technical Reference Digital Library (ETRDL) consists of a distributed collection of grey literature (technical reports, theses, workshop proceedings, preprints, etc.) in the areas of Computer Sciences and Applied Mathematics produced by members of the ERCIM Consortium. The ETRDL service currently allows public access through Internet to the technical reports produced by eight ERCIM organisations. ETRDL functionalities regards searching and browsing ERCIM collections to retrieval existing documents, submitting new documents in a specific collection and administer the ERCIM collections via a Web user interface. The aim of this document is to present an user guide for the authors that need to submit their new documents to ETRDL collections via a Web user interface.
A Homotopy Based Algorithm for Mixed Complementarity Problems
Authors: Stephen C. Billups
Venue:  (1998)

This paper develops an algorithm for solving mixed complementarity problems which is based upon probability one homotopy methods. After the complementarity problem is reformulated as a system of nonsmooth equations, a homotopy method is used to solve a sequence of smooth approximations to this system of equations. The global convergence properties of this approach are considerably stronger than other recent algorithms, depending on very weak assumptions about the problem. To improve efficiency, the homotopy algorithm is embedded in a generalized Newton-method.
Beamtrees: Compact Visualization of Large Hierarchies
Authors: Frank van Ham, Jarke J. van Wijk
Venue: Proceedings of the IEEE Symposium on Information Visualization (InfoVis'02) (2002)

Beamtrees are a new method for the visualization of large hierarchical data sets. Nodes are shown as stacked circular beams, such that both the hierarchical structure as well as the size of nodes are depicted. The dimensions of beams are calculated using a variation of the treemap algorithm. A small user study indicated that beamtrees are significantly more effective than nested treemaps and cushion treemaps for the extraction of global hierarchical information.
Multistage Interconnection Network Reliability
Authors: T J Blake, S K Trivedi
Venue:  (1987)

In this paper, we examine the reliability of an unique-path Multistage Interconnection Network (MIN) and two fault-tolerant schemes aimed at improving system reliability. These two schemes are the extra stage and the redundant network. We derive exact closed-form expressions for the time-dependent reliability of the $8$ x $8$ and $16$ x $16$ Shuffle-Exchange multistage interconnection Networks (SENs) and SENs with an additional stage (SEN+). These expressions are derived without any assumptions regarding the underlying component-lifetime-distributions. We also examine the distributional sensitivity, and show that for the networks examined the exponential distribution provides a conservative estimate of the reliability of these MINs if the components have an increasing-failure-rate lifetime-distribution. Further, we derive a tight reliability lower bound that is useful for the analysis of larger networks. We provide numerical results for networks as large as $1024$ x $1024$. A comparison of these networks shows that on the basis of reliability, the SEN+ is superior to both the SEN and the redundant SEN. We extend our results to the case of an (uniform) Omega network, and show that based on both reliability and cost (in terms of gate complexity), $2$ x $2$ switching elements are optimal for both the SEN and SEN+.
Energy Optimization of Algebraic Multigrid Bases
Authors: Marian Brezina, Jan Mandel, Petr Vanek
Venue:  (1998)

We propose a fast iterative method to optimize coarse basis functions in algebraic multigrid by minimizing the sum of their energies, subject to the condition that linear combinations of the basis functions equal to given zero energy modes, and subject to restrictions on the supports of the coarse basis functions. The convergence rate of the minimization algorithm is bounded independently of the meshsize under usual assumptions on finite elements. The first iteration gives exactly the same basis functions as our earlier method using smoothed aggregation. The construction is presented for scalar problems as well as for linear elasticity. Computational results on difficult industrial problems demonstrate that the use of energy minimal basis functions improves algebraic multigrid performance and yields a more robust multigrid algorithm than smoothed aggregation.