ppxscal/embedding_network huggingface dataset:
Scaling up partial evaluation for optimizing the Sun commercial RPC protocol
Authors: Gilles Muller, Eugen-Nicolae Volanschi, Renaud Marlet
Venue: Proceedings of the 1997 ACM SIGPLAN symposium on Partial evaluation and semantics-based program manipulation (1997)

We report here a successful experiment in using partial evaluation on a realistic program, namely the Sun commercial RPC (Remote Procedure Call) protocol. The Sun RPC is implemented in a highly generic way that offers multiple opportunities of specialization.Our study also shows the incapacity of traditional binding-time analyses to treat real system programs. Our experiment has been made with Tempo, a partial evaluator for C programs targeted towards system software. Tempo's binding-time analysis had to be improved to integrate partially static data structures (interprocedurally), context sensitivity, use sensitivity and return sensitivity.The Sun RPC experiment files, including the specialized implementation, are publicly available upon request to the authors.
Snowball: Scalable Storage on Networks of Workstations with Balanced Load
Authors: Radek Vingralek, Yuri Breitbart, Gerhard Weikum
Venue: Distributed and Parallel Databases (1998)

Networks of workstations are an emerging architectural paradigm for high-performance parallel and distributed systems. Exploiting networks of workstations for massive data management poses exciting challenges. We consider here the problem of managing record-structured data in such an environment. For example, managing collections of HTML documents on a cluster of WWW servers is an important application for which our approach provides support. The records are accessed by a dynamically growing set of clients based on a search key (e.g., a URL). To scale up the throughput of client accesses with approximately constant response time, the records and thus also their access load are dynamically redistributed across a growing set of workstations. The paper addresses two problems of realistic workloads: skewed access frequencies to the records and evolving access patterns where previously cold records may become hot and vice versa. Our solution incorporates load tracking at different levels of granularity and automatically chooses the appropriate granularity for dynamic data migrations. Experimental results based on a detailed simulation model show that our method is indeed successful in providing scalable cost/performance and explicitly controlling its level.
Interprocedural Partial Redundancy Elimination With Application to Distributed Memory Compilation
Authors: Gagan Agrawal
Venue: IEEE Transactions on Parallel and Distributed Systems (1998)

Partial Redundancy Elimination (PRE) is a general scheme for suppressing partial redundancies which encompasses traditional optimizations like loop invariant code motion and redundant code elimination. In this paper, we address the problem of performing this optimization interprocedurally. We present an Interprocedural Partial Redundancy Elimination (IPRE) scheme based upon a new, concise, full program representation. Our method is applicable to arbitrary recursive programs. We use interprocedural partial redundancy elimination for placement of communication and communication preprocessing statements while compiling for distributed memory parallel machines. We have implemented our scheme as an extension to the Fortran D compilation system. We present experimental results from two codes compiled using our system to demonstrate the useful of IPRE in distributed memory compilation.
Recursive 3-D Visual Motion Estimation Using Subspace Constraints
Authors: Stefano Soatto, Pietro Perona
Venue: International Journal of Computer Vision (1997)

The 3-D motion of a camera within a static environment produces a sequence of time-varying images that can be used for reconstructing the relative motion between the scene and the viewer. The problem of reconstructing rigid motion from a sequence of perspective images may be characterized as the estimation of the state of a nonlinear dynamical system, which is defined by the rigidity constraint and the perspective measurement map. The time-derivative of the measured output of such a system, which is called the &ldquo;2-D motion field&rdquo; and is approximated by the &ldquo;optical flow&rdquo;, is bilinear in the motion parameters, and may be used to specify a subspace constraint on the direction of heading independent of rotation and depth, and a pseudo-measurement for the rotational velocity as a function of the estimated heading. The subspace constraint may be viewed as an implicit dynamical model with parameters on a differentiable manifold, and the visual motion estimation problem may be cast in a system-theoretic framework as the identification of such an implicit model. We use techniques which pertain to nonlinear estimation and identification theory to recursively estimate 3-D rigid motion from a sequence of images independent of the structure of the scene. Such independence from scene-structure allows us to deal with a variable number of visible feature-points and occlusions in a principled way. The further decoupling of the direction of heading from the rotational velocity generates a filter with a state that belongs to a two-dimensional and highly constrained state-space. As a result, the filter exhibits robustness properties which are highlighted in a series of experiments on real and noisy synthetic image sequences. While the position of feature-points is not part of the state of the model, the innovation process of the filter describes how each feature is compatible with a rigid motion interpretation, which allows us to test for outliers and makes the filter robust with respect to errors in the feature tracking/optical flow, reflections, T-junctions. Once motion has been estimated, the 3-D structure of the scene follows easily. By releasing the constraint that the visible points lie in front of the viewer, one may explain some psychophysical effects on the nonrigid percept of rigidly moving objects.
Multigrid Algorithms for Nonconforming and Mixed Methods for Nonsymmetric and Indefinite Problems
Authors: Zhangxin Chen, Do Y. Kwak, Yoon J. Yon
Venue: SIAM Journal on Scientific Computing (1998)

In this paper we consider multigrid algorithms for nonconforming and mixed finite element methods for nonsymmetric and/or indefinite elliptic problems. We show that a simple $\cal V$-cycle multigrid iteration using conforming coarse-grid corrections converges at a uniform rate provided that the coarsest level in the multilevel iteration is sufficiently fine (but independent of the number of multigrid levels). Various types of smoothers for the nonsymmetric and indefinite problems are discussed. Extensive numerical results are presented.
Position statements on strategic directions for research on programming languages
Authors: Chris Hankin, Hanne Riis Nielson, Jens Palsberg
Venue: ACM SIGPLAN Notices (1997)

One of the working groups at the workshop on Strategic Directions in Computing Research was concerned with Programming Languages. We summarise the strategic directions identified by the group and we introduce 16 of the position statements that formed the basis for the report. These statements can then be found at the following pages.
Intelligent Selection of Instances for Prediction Functions in LazyLearning Algorithms
Authors: Jianping Zhang, Yee-Sat Yim, Jumming Yang
Venue: Artificial Intelligence Review (1997)

Lazy learning methods for function prediction use different prediction functions. Given a set of stored instances, a similarity measure, and a novel instance, a prediction function determines the value of the novel instance. A prediction function consists of three components: a positive integer k specifying the number of instances to be selected, a method for selecting the k instances, and a method for calculating the value of the novel instance given the k selected instances. This paper introduces a novel method called k surrounding neighbor (k-SN) for intelligently selecting instances and describes a simple k-SN algorithm. Unlike k nearest neighbor (k-NN), k-SN selects k instances that surround the novel instance. We empirically compared k-SN with k-NN using the linearly weighted average and local weighted regression methods. The experimental results show that k-SN outperforms k-NN with linearly weighted average and performs slightly better than k-NN with local weighted regression for the selected datasets.
Clock Skew Optimization for Peak Current Reduction
Authors: L. Benini, P. Vuillod, A. Bogliolo, G. De Micheli
Venue: Journal of VLSI Signal Processing Systems (1997)

The presence of large current peaks on the power and ground lines is a serious concern for designers of synchronous digital circuits. Current peaks are caused by the simultaneous switching of highly loaded clock lines and by the signal propagation through the sequential logic elements. In this work we propose a methodology for reducing the amplitude of the current peaks. This result is obtained by clock skew optimization. We propose an algorithm that, for a given clock cycle time, determines the clock arrival time at each flip-flop in order to minimize the current peaks while respecting timing constraint. Our results on benchmark circuits show that current peaks can be reduced without penalty on cycle time and average power dissipation. Our methodology is therefore well-suited for low-power systems with reduced supply voltage, where low noise margins are a primary concern.
Foundations for the implementation of higher-order subtyping
Authors: Karl Crary
Venue: Proceedings of the second ACM SIGPLAN international conference on Functional programming (1997)

We show how to implement a calculus with higher-order subtyping and subkinding by replacing uses of implicit subsumption with explicit coercions. To ensure this can be done, a polymorphic function is adjusted to take, as an additional argument, a proof that its type constructor argument has the desired kind. Such a proof is extracted from the derivation of a kinding judgement and may in turn require proof coercions, which are extracted from subkinding judgements. This technique is formalized as a type-directed translation from a calculus of higher-order subtyping to a subtyping-free calculus. This translation generalizes an existing result for second-order subtyping calculi (such as F le;).We also discuss two interpretations of subtyping, one that views it as type inclusion and another that views it is the existence of a well-behaved coercion, and we show, by a type-theoretic construction, that our translation is the minimum consequence of shifting from the inclusion interpretation to the coercion-existence interpretation. This construction shows that the translation is the natural one, and it also provides a framework for extending the translation to richer type systems. Finally, we show how the two interpretations can be reconciled in a common semantics. It is then easy to show the coherence of the translation relative to that semantics.
The marriage of Ada and Joe College
Authors: Charles B. Engle,  Jr.
Venue: Proceedings of the conference on TRI-ADA '90 (1990)

One thing that has been rather slow to develop has been the use of Ada as a language for instruction at colleges and universities. Several reasons for this deficiency have been discussed ad naseum and so will not be reiterated here. However, a promising new trend has been noted which bodes well for the future of Ada in academia. More and more educational institutions have adopted Ada as their primary language for instruction. This is not being done under some mandate or because of the threat of funding cuts, or anything else other than the intrinsic educational value of the language. Modern software engineering practices as we understand them today fit well with the semantics of the constructs of Ada. Thus, schools that adopt Ada find that it is easier to expect and to require good software engineering practices in the implementation of course assignments and to require the use of an Ada PDL in design. But that could also be done in almost any language, so what is the value of Ada? The students can grow with it! There is no need to use a language to teach introductory programming or introductory software engineering, and then a different language for concurrency or other topics that are more advanced. Thus, academia can use a single language for their instructional courses at all levels. It is my hope that Ada 9X will be an improved version of the existing language. If this is the case, then I sense an increase in the movement to the use of Ada in academia.
Grading student programs using ASSYST
Authors: David Jackson, Michelle Usher
Venue: ACM SIGCSE Bulletin (1997)

The task of grading solutions to student programming exercises is laborious and error-prone. We have developed a software tool called ASSYST that is designed to relieve a tutor of much of the burden of assessing such programs. ASSYST offers a graphical interface that can be used to direct all aspects of the grading process, and it considers a wide range of criteria in its automatic assessment. Experience with the system has been encouraging.
An approach to multimedia information management
Authors: S. Gallelli, C. Iacobelli, P. Marchisio
Venue: Proceedings of the 9th annual international ACM SIGIR conference on Research and development in information retrieval (1986)

The integrated management of multimedia information, that is of complex information consisting of conventional data, text, graphics, images and voice, is of great interest not only in fields like information Retrieval, Office Automation, Computer Aided Instruction, Computer Aided Design, but also in other emerging fields such as Tourist Applications, Computer generated films, Newspapers and magazines production, and so on. In this paper the definition of multimedia object, partially derived from the ECMA standard &ldquo;Office Document Architecture&rdquo;, is given and an approach to multimedia information management is proposed. A multilevel environment, where multimedia information can be handled, stored and retrieved and the inner level of which consists of a general purpose Multimedia Data Base Management System (MDBMS), is described. They are outlined the main functionalities that languages which describe and manipulate multimedia objects should provide.
Comparing Verification Systems: Interactive Consistency in ACL2
Authors: William D. Young
Venue: IEEE Transactions on Software Engineering (1997)

Achieving interactive consistency among processors in the presence of faults is an important problem in fault tolerant computing, first cleanly formulated by Lamport, Pease, and Shostak and solved in selected cases with their Oral Messages (OM) algorithm. Several machine-supported verifications of this algorithm have been presented, including a particularly elegant formulation and proof by John Rushby using EHDM and PVS. Rushby proposes interactive consistency as a benchmark problem for specification and verification systems. We present a formalization of the OM algorithm in the ACL2 logic and compare our formalization and proof to his. We draw some conclusions concerning the range of desirable features for verification systems. In particular, while higher-order functions, strong typing, lambda abstraction, and full quantification have some value they come with a cost; moreover, many uses of such features can be easily translated into simpler logical constructs, which facilitate more automated proof discovery. We offer a cautionary note about comparing systems with respect to a small set of problems in a limited domain.
Layout-driven RTL binding techniques for high-level synthesis using accurate estimators
Authors: Min Xu, Fadi J. Kurdahi
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (1997)

The importance of effective and efficient accounting of layout effects is well established in High-Level Synthesis (HLS), since it allows more realistic exploration of the design space and the generation of solutions with predictable metrics. This feature is highly desirable in order to avoid unnecessary iterations through the design process. In this article, we address the problem of layout-driven register-transfer-level (RTL) binding as this step has a direct relevance to the final performance of the design. By producing not only an RTL design but also an approximate physical topology of the chip-level implementation, we ensure that the solution will perform at the predicted metric once implemented, thus avoiding unnecessary delays in the design process.
The cluster hypothesis revisited
Authors: Ellen M. Voorhees
Venue: Proceedings of the 8th annual international ACM SIGIR conference on Research and development in information retrieval (1985)

A new means of evaluating the cluster hypothesis is introduced and the results of such an evaluation are presented for four collections. The results of retrieval experiments comparing a sequential search, a cluster-based search, and a search of the clustered collection in which individual documents are scored against the query are also presented. These results indicate that while the absolute performance of a search on a particular collection is dependent on the pairwise similarity of the relevant documents, the relative effectiveness of clustered retrieval versus sequential retrieval is independent of this factor. However, retrieval of entire clusters in response to a query usually results in a poorer performance than retrieval of individual documents from clusters.
Design of a communication system for a real-time C2 simulator
Authors: F. Dennis Kenyon, Terry J. Westley
Venue: Proceedings of the conference on TRI-ADA '90 (1990)

The design of a communication system reflects many decisions made after analysis of the requirements and evaluation of the goals of a particular program. This paper describes the key characteristics and design process of the Communication Services for a distributed real-time C2 (command and control) simulator. Many of the design choices were driven by or made possible by the choice of Ada as the implementation language. The final design was a result of careful study of these design alternatives. This process is discussed and the final Ada solution is presented along with the rationale for each decision. The choices made for this program are also contrasted with those made in other Ada-based communication systems described in [Atkinson], [Kamrad], and [Royce].
A new high-order absolutely-stable explicit numerical integration algorithm for the time-domain simulation of nonlinear circuits
Authors: R. Griffith, M. Nakhla
Venue: Proceedings of the 1997 IEEE/ACM international conference on Computer-aided design (1997)

A new numerical integration method for the time domain simulation of nonlinear circuits is presented. The new method does not belong to the traditional class of linear multistep methods. Consequently it is free from Dahlquist's barriers in terms of stability and order. The new method is shown to be both A-stable and at the same time of arbitrarily high order. In addition, the method is explicit in nature and does not require matrix inversion at each time step. Examples of linear and nonlinear circuit simulation are included. The proposed method significantly speeds up the time domain simulation of nonlinear circuits as it combines the efficiency of an explicit method with the accuracy and large step size possible with high order.
Classroom projects on database connectivity and the Web
Authors: Sub Ramakrishnan, B. Madhu Rao
Venue: ACM SIGCSE Bulletin (1997)

Most undergraduate curriculums in CS include at least a one semester study of data base management systems. In this paper, we take a closer look at a DBMS course we have offered recently and elaborate on a world wide web based database project in this course; it integrates a number of ideas not only from within DBMS but across other CS areas. We discuss the objectives underlying the design of the project and the ways in which these projects provide students with a feel for the organization and use of contemporary commercial database applications.
Assessing computer usage patterns in a software development course
Authors: Allen Parrish, David Cordes, Cynthia Lester, Deanne Moore
Venue: Proceedings of the twenty-eighth SIGCSE technical symposium on Computer science education (1997)

This paper reports the results of an exploratory study that measures computer usage patterns in a second-year, programming-intensive computer science course. In the study, we augmented the compilation process to unobtrusively mail a copy of the compiler listing to a central location. We then analyzed these data relative to the number of compiles and their time distribution in order to characterize computer usage patterns among the students. Our results show little correlation between any particular usage pattern and the quality of the final product.
Informed multi-process prefetching and caching
Authors: Andrew Tomkins, R. Hugo Patterson, Garth Gibson
Venue: Proceedings of the 1997 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1997)

Informed prefetching and caching based on application disclosure of future I/O accesses (hints) can dramatically reduce the execution time of I/O-intensive applications. A recent study showed that, in the context of a single hinting application, prefetching and caching algorithms should adapt to the dynamic load on the disks to obtain the best performance. In this paper, we show how to incorporate adaptivity to disk load into the TIP2 system, which uses cost-benefit analysis to allocate global resources among multiple processes. We compare the resulting system, which we call TIPTOE (TIP with Temporal Overload Estimators) to Cao et al's LRU-SP allocation scheme, also modified to include adaptive prefetching. Using disk-accurate trace-driven simulation we show that, averaged over eleven experiments involving pairs of hinting applications, and with data striped over one to ten disks, TIPTOE delivers 7% lower execution time than LRU-SP. Where the computation and I/O demands of each experiment are closely matched, in a two-disk array, TIPTOE delivers 18% lower execution time.
CSCW research at GMD-FIT: from basic groupware to the social Web
Authors: Peter Hoschka
Venue: ACM SIGGROUP Bulletin (1998)

GMD-FIT, the Institute for Applied Information Technology, is a research unit of GMD, Germany's National Research Center for Information Technology. It is located on GMD's Schloss Birlinghoven campus near Bonn. FIT is committed to inventing and designing innovative information technology which is really needed and wanted by users, is based on an understanding of human communication and human information processing, and is seamlessly integrated into the user environment. We pursue a vision of information technology moving bull; from personal computing to social computing, bull; from distributing information to helping utilize information, bull; from rigid systems to user-adaptive environments, and bull; from automation tools to enabling systems.The main application areas of FIT are office and home environments, and the area of medicine.The FIT institute is grouped in two departments: Cooperation Support Systems (CSCW) and Human- Computer Interaction (HCI). The following sections give an overview of our work in the CSCW group.