ppxscal/embedding_network huggingface dataset:
Exact switchbox routing with search space reduction
Authors: F. Schmiedle, D. Unruh, B. Becker
Venue: Proceedings of the 2000 international conference on Computer-aided design (2001)

We present an approach for exact switchbox routing that complements traditional routing techniques. It is particularly well suited for an application to dense problem instances and the completion of routing in subregions which turn out to be difficult for routing tools based on heuristic methods. The exact router proposed used symbolic methods i.e. MDDs (Multi-valued Decision Diagrams) for representation of the routing space. All possible solutions to the routing problem are represented by one single MDD and once this MDD is given, routability can be decided within constraint time. To reduce the search space of possible routing solutions, so-called forced cells are computed. Finally, experimental results are given. They show the feasibility and the practicability of the approach.
How to optimize proof-search in modal logics: new methods of proving redundancy criteria for sequent calculi
Authors: Andrei Voronkov
Venue: ACM Transactions on Computational Logic (TOCL) (2001)

We present a bottom-up decision procedure for propositional modal logic K based on the inverse method. The procedure is based on the &ldquo;inverted&rdquo; version of a sequent calculus. To restrict the search space, we prove a number of redundancy criteria for derivations in the sequent calculus. We introduce a new technique of proving redundancy criteria, based on the analysis of tableau-based derivations in K. Moreover, another new technique is based on so-called traces. A new search with a strong notion of subsumption. This technique is based on so-called traces. A new formalization of the inverse method in the form of a path calculus considerably simplifies all proofs as compared to the previously published presentations of the inverse method. Experimental results demonstrate that our method is competitive with many state-of-the-art implementations of K.
Interactive mathematics via the Web using MathML
Authors: Francis J. Wright
Venue: ACM SIGSAM Bulletin (2000)

MathML is a mathematical markup language intended for displaying mathematics in web browsers. At present, it can be used to display mathematics generated dynamically in response to interactive queries only if the browsing and generating facilities are chosen carefully. This paper examines the background and possible options, and describes some of the details of the use of MathML to display the output from a web-based demonstration of an ordinary differential equation solver running in REDUCE. Two screenshots showing examples of rendered MathML output are included.
Global load balancing with parallel mesh adaption on distributed-memory systems
Authors: Rupak Biswas, Leonid Oliker, Andrew Sohn
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

Dynamic mesh adaption on unstructured grids is a powerful tool for efficiently computing unsteady problems to resolve solution features of interest. Unfortunately, this causes load imbalance among processors on a parallel machine. This paper describes the parallel implementation of a tetrahedral mesh adaption scheme and a new global load balancing method. A huristic remapping algorithm is presented that assigns partitions to processors such that the redistribution cost is minimized. Results indicate that the paralel performance of the mesh adaption code depends on the nature of the adaption region and show a 35.5X speedup on 64 processors when about 35% of the mesh is randomly adapted. For large-scale scientific computations, our load balancing strategy gives almost a sixfold reduction in solver execution times over non-balanced loads. Furthermore, our heuristic remapper yields processor assignments that are less than 3% off the optimal solutions but requries only 1% of the computational time.
The impact of scanners on employment in supermarkets
Authors: Bruce Gilchrist, Arlaana Shenkin
Venue: Communications of the ACM (1982)

A brief review is given of the early estimates of the rate at which scanners would be installed in supermarkets and the resulting labor and consumer responses. The actual situation in 1979 is then discussed and detailed labor savings achieved by one supermarket chain are given. A fully scanner-equipped supermarket is estimated to have a 5 percent lower labor requirement than an unautomated store with the same volume. It is projected that 50 percent of the 23,000 large supermarkets will install scanners by 1984 with the remainder doing so by 1988. At full penetration, scanners will reduce total industry employment by approximately 50,000. Few actual layoffs will occur because of the high turnover in the industry. Furthermore, the stores that install scanners may attract customers from nonautomated stores leaving those stores to handle the job losses.
Intelligent speech for information systems: towards biliteracy and trilingualism
Authors: Helen M. Meng
Venue: Proceedings on the 2000 conference on Universal Usability (2000)

This paper reports on our research and development effort in human-computer spoken language interfaces, capable of processing English and Chinese, including two dialects for Chinese (Cantonese and Putonghua). This is the language environment in Hong Kong, and in order to develop human-computer spoken language interfaces that can be used by almost anybody in the region, we strive to develop speech and language technologies capable of handling biliteracy and trilingualism. The context of use is in accessing real-time information in the financial domain.
Using sparse crossbars within LUT
Authors: Guy Lemieux, David Lewis
Venue: Proceedings of the 2001 ACM/SIGDA ninth international symposium on Field programmable gate arrays (2001)

In FPGAs, the internal connections in a cluster of lookup tables (LUTs) are often fully-connected like a full crossbar. Such a high degree of connectivity makes routing easier, but has significant area overhead. This paper explores the use of sparse crossbars as a switch matrix inside the clusters between the cluster inputs and the LUT inputs. We have reduced the switch densities inside these matrices by 50% or more and saved from 10 to 18% in area with no degradation to critical-path delay. To compensate for the loss of routability, increased compute time and spare cluster inputs are required. Further investigation may yield modest area and delay reductions.
Quantifying the utility of parallel corpora
Authors: Martin Franz, J. Scott McCarley, Todd Ward, Wei-Jing Zhu
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

Our English-Chinese cross-language IR system is trained from parallel corpora; we investigate its performance as a function of training corpus size for three different training corpora. We find that the performance of the system as trained on the three parallel corpora can be related by a simple measure, namely the out-of-vocabulary rate of query words.
Provably good global buffering by multi-terminal multicommodity flow approximation
Authors: Feodor F. Dragan, Andrew B. Kahng, Ion Mandoiu, Sudhakar Muddu, Alexander Zelikovsky
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

To implement high-performance global interconnect without impacting the placement and performance of existing blocks, the use of buffer blocks is becoming increasingly popular in structured-custom and block-based ASIC methodologies. Recent works by Cong, Kong and Pan [5] and Tang and Wong [18] give algorithms to solve the buffer block planning problem. In this paper, we address the problem of how to perform buffering of global multiterminal nets given an existing buffer block plan. We give a provably good algorithm based on a recent approach of Garg and Knemann [8] and Fleischer [7] (see also Albrecht [1] and Dragan et al. [6]). Our method routes connections using available buffer blocks, such that required upper and lower bounds on buffer intervals - as well as wirelength upper bounds per connection - are satisfied. In addition, our algorithm allows more than one buffer to be inserted into any given connection and observes buffer parity constraints. Most importantly, and unlike previous works on the problem [5, 18, 6], we take into account multiterminal nets. Our algorithm outperforms existing algorithms for the problem [5, 6], which are based on 2-pin decompositions of the nets. The algorithm has been validated on top-level layouts extracted from a recent high-end microprocessor design.
Efficient object sampling via weak references
Authors: Ole Agesen, Alex Garthwaite
Venue: Proceedings of the 2nd international symposium on Memory management (2000)

The performance of automatic memory management may be improved if the policies used in allocating and collecting objects had knowledge of the lifetimes of objects. To date, approaches to the pretenuring of objects in older generations have relied on profile-driven feedback gathered from trace runs. This feedback has been used to specialize allocation sites in a program. These approaches suffer from a number of limitations. We propose an alternative that through efficient sampling of objects allows for on-line adaption of allocation sites to improve the efficiency of the memory system. In doing so, we make use of a facility already present in many collectors such as those found in Java&trade; virtual machines: weak references. By judiciously tracking a subset of allocated objects with weak references, we are able to gather the necessary statistics to make better object-placement decisions.
A computer science course program for small colleges
Authors: Gerald L. Engel
Venue: Communications of the ACM (1973)

The ACM Subcommittee on Small College Programs of the Committee on Curriculum in Computer Science (C3S) was appointed in 1969 to consider the unique problems of small colleges and universities, and to make recommendations regarding computer science programs at such schools. This report, authorized by both the subcommittee and C3S, supplies a set of recommendations for courses and necessary resources. Implementation problems are discussed, specifically within the constraints of limited faculty and for the purposes of satisfying a wide variety of objectives. Detailed descriptions of four courses are given; suggestions are made for more advanced work; and an extensive library list is included.
Implementation of aural attributes for simulation of room effects in virtual environments
Authors: Kenji Suzuki, Yuji Nishoji, Jens Herder
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

The audio design for vitural environments includes simulation of acoustical room properties besides specifying sound sources and sinks and their behavior. Virtual environments supporting room reverberation not only gain realism but also provide additional information to the user about surrounding space. Catching the different sound properties by the different spaces requires partitioning the space by the properties of aural spaces. We define soundscape and aural attributes as an application and multimedia content interface. Calculated data on an abstract level is sent to spatialization backends. Part of this research was the implementation of a device driver for the Roland Sound Space Processor. This device not only directionalizes sound sources, but also controls room effects like reverberation.
Archaelogy of computers: reminiscences, 1945-1947
Authors: Franz L. Alt
Venue: Communications of the ACM (1972)

The period preceding the founding of ACM was dominated by the first large computer ENIAC. Its characteristics, described here, foreshadow later developments.
Consistency management in Deno
Authors: Peter J. Keleher, Ugur Cetintemel
Venue: Mobile Networks and Applications (2000)

We describe a new replicated&dash;object protocol designed for use in mobile and weakly&dash;connected environments. The protocol differs from previous protocols in combining epidemic information propagation with voting, and in using fixed per&dash;object currencies for voting. The advantage of epidemic protocols is that data movement only requires pair&dash;wise communication. Hence, there is no need for a majority quorum to be available and simultaneously connected at any single time. The protocols increase availability by using voting, rather than primary&dash;copy or primary&dash;commit schemes. Finally, the use of per&dash;object currencies allows voting to take place in an entirely decentralized fashion, without any server having complete knowledge of group membership. We show that currency allocation can be used to implement diverse policies. For example, uniform currency distributions emulate traditional voting schemes, while allocating all currency to a single server emulates a primary&dash;copy scheme. We present simulation results showing both schemes, as well as the performance advantages of using currency proxies to temporarily reallocate currency during planned disconnections. Furthermore, we discuss an initial design of the underlying replicated&dash;object system and present a basic API.
Coven: brewing better collaboration through software configuration management
Authors: Mark C. Chu-Carroll, Sara Sprenkle
Venue: ACM SIGSOFT Software Engineering Notes (2000)

Our work focuses on building tools to support collaborative software development. We are building a new programming environment with integrated software configuration management which provides a variety of features to help programming teams coordinate their work. In this paper, we detail a hierachy-based software configuration management system called Coven, which acts as a collaborative medium for allowing teams of programmers to cooperate. By providing a family of inter-related mechanisms, our system provides powerful support for cooperation and coordination in a manner which matches the structure of development teams.
Buffered Steiner trees for difficult instances
Authors: C. J. Alpert, Miloš Hrkić, J. Hu, A. B. Kahng, J. Lillis, B. Liu, S. T. Quay, S. S. Sapatnekar, A. J. Sullivan, P. Villarrubia
Venue: Proceedings of the 2001 international symposium on Physical design (2001)

Buffer insertion has become an increasingly critical optimization in high performance design. The problem of finding a delay-optimal buffered Steiner tree has been an active area of research, and excellent solutions exist for most instances. However, current approaches fail to adequately solve a particular class of real-world &ldquo;difficult&rdquo; instances which are characterized by a large number of sinks, variations in sink criticalities, and varying polarity requirements. We propose a new Steiner tree construction called C-Tree for these instance types. When combined with van Ginneken style buffer insertion, C-Tree achieves higher quality solutions with fewer resources compared to traditional approaches.
Fusion-based register allocation
Authors: Guei-Yuan Lueh, Thomas Gross, Ali-Reza Adl-Tabatabai
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (2000)

The register allocation phase of a compiler maps live ranges of a program to registers. If there are more candidates than there are physical registers, the register allocator must spill a live range (the home location is in memory) or split a live range (the live range occupies multiple locations). One of the challenges for a register allocator is to deal with spilling and splitting together. Fusion-based register allocation uses the structure of the program to make splitting and spilling decisions, with the goal to move overhead operations to infrequently executed parts of a program. The basic idea of fusion-based register allocation is to build up the interference graph. Starting with some base region (e.g., a basic block, a loop), the register allocator adds basic blocks to the region and incrementallly builds the interference graph. When there are more live ranges than registers, the register allocator selects live ranges to split; these live ranges are split along the edge that was most recently added to the region. This article describes fusion-based register allocation in detail and compares it with other approaches to register allocation. For programs from the SPEC92 suite, fusion-based register allocation can improve the execution time (of optimized programs, for the MIPS architecture) by up to 8.4% over Chaitin-style register allocation.
The notification collage: posting information to public and personal displays
Authors: Saul Greenberg, Michael Rounding
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2001)

The Notification Collage (NC) is a groupware system where distributed and co-located colleagues comprising a small community post media elements onto a real-time collaborative surface that all members can see. Akin to collages of information found on public bulletin boards, NC randomly places incoming elements onto this surface. People can post assorted media: live video from desktop cameras; editable sticky notes; activity indicator; slide shows displaying a series of digital photos, snapshots of a person's digitial desktop, and Web page thumbnails. User experiences show that NC becomes a rich resource for awareness and collaboration. Community members indicate their presence to others by posting live video. They regularly act on this information by engaging in text and video conversations. Because all people can overhear conversations, these become active opportunities to join in. People also post items they believe will be interesting to others, such as desktop snapshots and vacation photos. Finally, people use NC somewhat differently when it is displayed on a large public screen than when it appears on a personal computer.
Evolution on a chip: evolvable hardware aims to optimize circuit design
Authors: Nancy Forbes
Venue: Computing in Science and Engineering (2001)

"Nature is the grandest engineer known to man--though a blind one at that: her designs come into existence through the slow process, over millions of years, known as evolution by natural selection." Moshe Sipper speaks with a respect that borders on awe when referring to nature's ability to create living systems that can produce energy, process information, self-replicate, self-repair, function with defects, adapt to their surroundings, and improve the species over time through evolution. Sipper and his colleagues at the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland, are studying these natural processes to try to translate their underlying principles into the language of information technology--specifically, those aspects that bear on circuit design. "Nature has found effective ways to deal with large, complex systems, the numerous elements of which function imperfectly," muses Sipper. " That's where artifacts are going now, specifically electronic hardware."
Proving the correctness of heuristically optimized code
Authors: Hanan Samet
Venue: Communications of the ACM (1978)

A system for proving that programs written in a high level language are correctly translated to a low level language is described. A primary use of the system is as a postoptimization step in code generation. The low level language programs need not be generated by a compiler and in fact could be hand coded. Examples of the usefulness of such a system are given. Some interesting results are the ability to handle programs that implement recursion by bypassing the start of the program, and the detection and pinpointing of a wide class of errors in the low level language programs. The examples demonstrate that optimization of the genre of this paper can result in substantially faster operation and the saving of memory in terms of program and stack sizes.
Animated icons: re-inventing visual cues for the visually impaired computer user
Authors: Stephanie Ludi
Venue: Proceedings on the 2000 conference on Universal Usability (2000)

Universal access to information is critical for universal participation in society. The Graphical User Interface is a mainstream means for accessing the computing resources needed to access information. These interfaces have become challenging to the visually impaired. Many partially sighted individuals posses residual vision. While the enlargement of screen content is important, enlargement alone will not address all of issues involving the utilization of GUIs. While icons are generally useful, animation increases the usefulness of the icons. The sizes of static and animated icons are compared in order to ascertain the impact of animation on icon size.
Defining computer science
Authors: James W. McGuffee
Venue: ACM SIGCSE Bulletin (2000)

This paper explores the use and purpose of a definition of computer science from the perspective of an undergraduate student. In order to gain access to the topic, the nature and purpose of definitions are explored. Historical examples of computer science definitions are given. The paper concludes with an examination of how students define computer science and how we should use these definitions in computer science education.
Hierarchical B-spline refinement
Authors: David R. Forsey, Richard H. Bartels
Venue: Proceedings of the 15th annual conference on Computer graphics and interactive techniques (1988)

Refinement is usually advocated as a means of gaining finer control over a spline curve or surface during editing. For curves, refinement is a local process. It permits the change of control vertices and subsequent editing of the detail in one region of the curve while leaving control vertices in other regions unaffected. For tensor-product surfaces, however, refinement is not local in the sense that it causes control vertices far from a region of interest to change as well as changing the control vertices that influence the region. However, with some care and understanding it is possible to restrict the influence of refinement to the locality at which an editing effect is desired. We present a method of localizing the effect of refinement through the use of overlays, which are hierarchically controlled subdivisions. We also introduce two editing techniques that are effective when using overlays: one is direct surface manipulation through the use of edit points and the other is offset referencing of control vertices.
Hidden Markov modeling for network communication channels
Authors: Kavé Salamatian, Sandrine Vaton
Venue: Proceedings of the 2001 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2001)

In this paper we perform the statistical analysis of an Internet communication channel. Our study is based on a Hidden Markov Model (HMM). The channel switches between different states; to each state corresponds the probability that a packet sent by the transmitter will be lost. The transition between the different states of the channel is governed by a Markov chain; this Markov chain is not observed directly, but the received packet flow provides some probabilistic information about the current state of the channel, as well as some information about the parameters of the model. In this paper we detail some useful algorithms for the estimation of the channel parameters, and for making inference about the state of the channel. We discuss the relevance of the Markov model of the channel; we also discuss how many states are required to pertinently model a real communication channel.