ppxscal/embedding_network huggingface dataset:
Object-oriented modelling of parallel hardware systems
Authors: G. Schumacher, W. Nebel
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

Object-oriented techniques like inheritance promise great benefits for the specification and design of parallel hardware systems. The difficulties which arise from the use of inheritance in parallel hardware systems are analyzed in this article. Similar difficulties are well known in concurrent object-oriented programming as inheritance anomaly but are not yet investigated in object-oriented hardware design. A solution how to successfully deal with the anomaly is presented for a type based object-oriented extension to VHDL. Its basic idea is to separate the synchronization code (protocol specification) and the actual behavior of a method. Method guards which allow a method to execute if a guard expression evaluates to true are proposed to model synchronization constraints. It is shown how to implement a suitable re-schedule mechanism for methods as part of the synchronization code to handle the case that a guard expression is evaluated to false.
Low contention semaphores and ready lists
Authors: Peter J. Denning, T. Don Dennis, Jeffrey A. Brumfield
Venue: Communications of the ACM (1981)

A method for reducing semaphore and ready-list contention in multiprocessor operating systems is described. Its correctness is established. Its performance is compared with conventional implementations. A ready list implemented as a ring network is proposed and evaluated.
On Mod-p Alon-Babai-Suzuki Inequality
Authors: Jin Qian, D. K. Ray-Chaudhuri
Venue: Journal of Algebraic Combinatorics: An International Journal (2000)

Alon, Babai and Suzuki proved the following theorem:i>Let p be a prime and let K, i>L be two disjoint subsets of &lcub;0, 1, &hellip; , i>p &minus; 1&rcub;. i>Let &verbar;i>K&verbar; &equals; i>r, &verbar;i>L&verbar; &equals; i>s, i>and assume r(i>s &minus; r + 1) &le; i>p &minus; 1 i>and n &ge; i>s + kr where kr is the maximal element of K. Let {\cal F} i>be a family of subsets of an n-element set. Suppose that(i) &verbar;i>F&verbar; &isin; i>K (mod i>p) i>for each F &isin; {\cal F}&semi;(ii) &verbar;i>E {\cap} i>F&verbar; &isin; i>L (mod i>p) i>for each pair of distinct sets E, i>F &isin; {\cal F}.i>Then |{\cal F}| \leq ({n\atop s}) + ({n\atop s-1}) + \cdots + ({n\atop s-r+1}).They conjectured that the condition that i>r(i>s &minus; r + 1) &le; i>p &minus; 1 in the theorem can be dropped and the same conclusion should hold. In this paper we prove that the same conclusion holds if the two conditions in the theorem, i.e. i>r(i>s &minus; r + 1) &le; i>p &minus; 1 and i>n &ge; i>s + i>kr are replaced by a single more relaxed condition 2i>s &minus; i>r &le; i>n.
Object Recognition Using Shape-from-Shading
Authors: Philip L. Worthington, Edwin R. Hancock
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2001)

This paper investigates whether surface topography information extracted from intensity images using a recently reported shape-from-shading (SFS) algorithm can be used for the purposes of 3D object recognition. We consider how curvature and shape-index information delivered by this algorithm can be used to recognize objects based on their surface topography. We explore two contrasting object recognition strategies. The first of these is based on a low-level attribute summary and uses histograms of curvature and orientation measurements. The second approach is based on the structural arrangement of constant shape-index maximal patches and their associated region attributes. We show that region curvedness and a string ordering of the regions according to size provides recognition accuracy of about 96 percent. By polling various recognition schemes, including a graph matching method, we show that a recognition rate of 98-99 percent is achievable.
Earthquake ground motion modeling on parallel computers
Authors: Hesheng Bao, Jacobo Bielak, Omar Ghattas, Loukas F. Kallivokas, David R. O'Hallaron, Jonathan R. Shewchuk, Jifeng Xu
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

We describe the design and discuss the performance of a parallel elastic wave propagation simulator that is being used to model and study earthquake-induced ground motion in large sedimentary basins. The components of the system include mesh generators, a mesh partitioner, a parceler, and a parallel code generator, as well as parallel numerical methods for applying seismic forces, incorporating absorbing boundaries, and solving the discretized wave propagation problem. We discuss performance on the Cray T3D for unstructured mesh wave propagation problems of up to 14 million tetrahedra. By paying careful attention to each step of the process, we obtain excellent performance despite the highly irregular structure of the coefficient matrices of the problem. The mesh generator, partitioner, parceler, and code generator have been incorporated into an integrated toolset/compiler. This system, called Archimedes, automates the solution of unstructured mesh PDE problems on parallel computers, and is being used for other unstructured mesh applications beyond ground motion modeling.
What packets may come: automata for network monitoring
Authors: Karthikeyan Bhargavan, Satish Chandra, Peter J. McCann, Carl A. Gunter
Venue: ACM SIGPLAN Notices (2001)

We consider the problem of monitoring an interactive device, such as an implementation of a network protocol, in order to check whether its execution is consistent with its specification. At rst glance, it appears that a monitor could simply follow the input-output trace of the device and check it against the specification. However, if the monitor is able to observe inputs and outputs only from a vantage point external to the device---as is typically the case---the problem becomes surprisingly difficult. This is because events may be bu ered, and even lost, between the monitor and the device, in which case, even for a correctly running device, the trace observed at the monitor could be inconsistent with the specification.In this paper, we formulate the problem of external monitoring as a language recognition problem. Given a specification that accepts a certain language of input-output sequences, we de ne another language that corresponds to input-output sequences observable externally. We also give an algorithm to check membership of a string in the derived language. It turns out that without any assumptions on the specification, this algorithm may take unbounded time and space. To address this problem, we de ne a series of properties of device specifications or protocols that can be exploited to construct e cient language recognizers at the monitor. We characterize these properties and provide complexity bounds for monitoring in each case.To illustrate our methodology, we describe properties of the Internet Transmission Control Protocol (TCP), and identify features of the protocol that make it challenging to monitor e ciently.
Isodual Codes over {\bb Z}_{2k} and Isodual Lattices
Authors: Christine Bachoc, T. Aaron Gulliver, Masaaki Harada
Venue: Journal of Algebraic Combinatorics: An International Journal (2000)

A code is called isodual if it is equivalent to its dual code, and a lattice is called isodual if it is isometric to its dual lattice. In this note, we investigate isodual codes over {\bb Z}_{2k}. These codes give rise to isodual lattices; in particular, we construct a 22-dimensional isodual lattice with minimum norm 3 and kissing number 2464.
Two Hadamard numbers for matrices
Authors: Garrett Birkhoff
Venue: Communications of the ACM (1975)

A discussion is given of two functions of the entries of a square matrix, both related to Hadamard's determinant theorem, which have some merits as alternatives to norm-bound &ldquo;condition numbers.&rdquo; One (for linear systems) is known; the other (for eigensystems) seems to be new.
The ergonomics of hypertext narative: usability testing as a tool for evaluation and redesign
Venue: ACM Journal of Computer Documentation (JCD) (2001)

While usability research concentrates on evaluating informational documents and Web sites, significant insights can be gained from performing usability testing on texts designed for pleasure reading, such as hypertext narratives. This article describes the results of such a test. The results demonstrate that the navigation systems required for such texts can significantly interfere with readers ability to derive value or pleasure from the fiction. The results emphasize the importance of hypertext authors providing more linear paths through texts and of simplifying the navigational apparatus required to read them.
Java bytecode compression for low-end embedded systems
Authors: Lars Ræder Clausen, Ulrik Pagh Schultz, Charles Consel, Gilles Muller
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (2000)

A program executing on a low-end embedded system, such as a smart-card, faces scarce memory resources and fixed execution time constraints. We demonstrate that factorization of common instruction sequences in Java bytecode allows the memory footprint to be reduced, on average, to 85% of its original size, with a minimal execution time penalty. While preserving Java compatibility, our solution requires only a few modifications which are straightforward to implement in any JVM used in a low-end embedded system.
Improving the performance of the cyberlink mental interface with &ldquo;yes / no program&rdquo;
Authors: Eamon Doherty, Gilbert Cockton, Chris Bloor, Dennis Benigno
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2001)

We summarise the results of the first studies to investigate the Cyberlink brain body interface as an assistive technology. Three phases of studies and a contextual inquiry were performed with a range of users. A focus group was formed from brain-injured users with locked-in syndrome who have no other method of communication or control of a computer than the Cyberlink. Versions of a Yes/No program were then created to allow communication and have achieved some success with the focus group. The purpose of this paper is to discuss how this program has been improved and what steps need to be taken to create communication programs for persons with severe motor impairment. As a result of our experiences, we have been able to develop a set of design guidelines for brain-body interface operated Yes/No programs. These are presented and justified on the basis of our experiences. We also raise some general issues for assistive technologies of this nature.
Comments on the algorithms of Verhelst for the conversion of limited-entry decision tables to flowcharts
Authors: P. J. H. King, R. G. Johnson
Venue: Communications of the ACM (1974)

In his interesting contribution to the study of the conversion of limited-entry decision tables to flowcharts or sequential testing procedures, Verhelst [1] presents two algorithms, one of which is claimed to produce the optimal flowchart with respect to run-time. Unfortunately this minimum run-time algorithm does not always produce the result claimed, as we illustrate by example below.
Diogenes: a web search agent for person images
Authors: Yuksel Alp Aslandogan, Clement T. Yu
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

Diogenes is a web image search agent that retrieves web pages and associates a person name with each facial image on those pages. To accomplish its goal, Diogenes relies on two types of evidence: Visual and textual. A face detection module examines the images on the web page for human faces. A face recognition module identifies the face by using a database of known person images. A text/HTML analysis module analyses the body of the text with the aim of finding clues about who appears in each image. The outputs of the face detection, text/HTML analysis and face recognition modules are merged using different evidence combination mechanisms to classify each image. Diogenes have been successfully used to retrieve person images from the web with an average precision surpassing those of some commercial image search engines.
An ambiguity in the description of ALGOL 60
Authors: John G. Herriot
Venue: Communications of the ACM (1969)

When Algorithm 355 [Comm. ACM 12 (Oct. 1969), 562] was originally submitted to the Algorithms Department it contained a construct which pointed up an ambiguity in the description of ALGOL 60 [Revised Report on the Algorithmic Language ALGOL 60, Comm. ACM 6 (Jan. 1963), 1-17]. This ambiguity was not mentioned by Donald Knuth [The Remaining Trouble Spots in ALGOL 60, Comm. ACM 10 (Oct. 1967), 611-618].
Universal Series and Parallel Immittance Simulators Using Four Terminal Floating Nullors
Authors: Uğur Çam, Oğuzhan ÇiÇekoğlu, Hakan Kuntman
Venue: Analog Integrated Circuits and Signal Processing (2000)

Most of the presented immittance simulator topologies in the literature realize certain types of inductor&ndash;resistor&ndash;capacitor combinations using the same configuration. In this study, a series and a parallel immittance simulator employing FTFNs in its most general form are introduced. The presented circuits are universal and able to simulate series and parallel (&plusmn;G), (&plusmn;L), (&plusmn;C) for which all values are independently adjustable. The simulator circuits do not require any component matching constraint, except for the realization of pure inductance. Strong reduction in the number of active and passive elements is possible for special cases. The performance of the proposed universal immittance simulators is demonstrated on two chosen typical application examples by PSPICE simulations.
A note on the dangling else ALGOL 60
Authors: Arthur F. Kaupe,  Jr.
Venue: Communications of the ACM (1963)

Some revisions of ALGOL 60 are proposed, which not only eliminate certain ambiguous statements but also add some convenience to the language. A discussion of the background of the problem and a sketch of a proof that the ambiguities have been removed is included.
A linear space algorithm for computing the hermite normal form
Authors: Daniele Micciancio, Bogdan Warinschi
Venue: Proceedings of the 2001 international symposium on Symbolic and algebraic computation (2001)

Computing the Hermite Normal Form of an n &times; n integer matrix using the best current algorithms typically requires &Ogr;(n3 log M) space, where M is a bound on the entries of the input matrix. Although polynomial in the input size (which is &Ogr;(n2 log M)), this space blow-up can easily become a serious issue in practice when working on big integer matrices. In this paper we present a new algorithm for computing the Hermite Normal Form which uses only &Ogr;(n2 log M) space (i.e., essentially the same as the input size). When implemented using standard algorithms for integer and matrix multiplication, our algorithm has the same time complexity of the asymptotically fastest (but space inefficient) algorithms. We also present a heuristic algorithm for HNF that achieves a substantial speedup when run on randomly generated input matrices.
An efficient composite formula for multidimensional quadrature
Authors: Henry C. Thacher,  Jr.
Venue: Communications of the ACM (1964)

A (2s+1)-point, second-degree quadrature formula for integration over an s-dimensional hyper-rectangle is presented. All but one of the points lie on the surface with weights of opposite sign attached to points on opposite faces. When a large volume is subdivided into congruent rectangular subdivisions, only one point is required in each interior subdivision to achieve second-degree accuracy.
Entropy-preserving cuttings and space-efficient planar point location
Authors: Sunil Arya, Theocharis Malamatos, David M. Mount
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Point location is the problem of preprocessing a planar polygonal subdivision S into a data structure in order to determine efficiently the cell of the subdivision that contains a given query point. Given the probabilities pz that the query point lies within each cell z &isin; S, a natural question is how to design such a structure so as to minimize the expected-case query time. The entropy H of the probability distribution is the dominant term in the lower bound on the expected-case search time. Clearly the number of edges n of the subdivision is a lower bound on the space required. There is no known approach that simultaneously achieves the goals of H + &Ogr;(H) query time and &Ogr;(n) space. In this paper we introduce entropy-preserving cuttings and show how to use them to achieve query time H + &Ogr;(H), using only &Ogr;(n log* n) space.
New TPC benchmarks for decision support and web commerce
Authors: Meikel Poess, Chris Floyd
Venue: ACM SIGMOD Record (2000)

For as long as there have been DBMS's and applications that use them, there has been interest in the performance characteristics that these systems exhibit. This month's column describes some of the recent work that has taken place in TPC, the Transaction Processing Performance Council.TPC-A and TPC-B are obsolete benchmarks that you might have heard about in the past. TPC-C V3.5 is the current benchmark for OLTP systems. Introduced in 1992, it has been run on many hardware platforms and DBMS's. Indeed, the TPC web site currently lists 202 TPC-C benchmark results. Due to its maturity, TPC-C will not be discussed in this article.We've asked two very knowledgeable individuals to write this article. Meikel Poess is the chair of the TPC H and TPC-R Subcommittees and Chris Floyd is the chair of the TPC-W Subcommittee. We greatly appreciate their efforts.A wealth of information can be found at the TPC web site [ 1 ]. This information includes the benchmark specifications themselves, TPC membership information, and benchmark results.
Testing graphs for colorable properties
Authors: Eldar Fischer
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Let P be a property of graphs. An &isin;-test for P is a randomized algorithm which, given the ability to make queries whether a desired pair of vertices of an input graph G with n vertices are adjacent or not, distinguishes, with high probability, between the case of G satisfying P and the case that it has to be modified by adding and removing more than &isin;(n 2) edges to make it satisfy P. The property P is called testable, if for every &isin; there exists an &isin;-test for P whose total number of queries is independent of the size of the input graph. Goldreich, Goldwasser and Ron [7] showed that certain graph properties, like k-colorability, admit an &isin;-test. In [2] a first step towards a logical characterization of the testable graph properties was made by proving that all first order properties of type &ldquo;&exist;&forall;&rdquo; are testable while there exist first order graph properties of type &ldquo;&forall;&exist;&rdquo; which are not testable. For proving the positive part, it was shown that all properties describable by a very general type of coloring problem are testable. While this result is tight from the standpoint of first order expressions, further steps towards the characterization of the testable graph properties can be taken by considering the coloring problem instead. It is proven here that other classes of graph properties, describable by various generalizations of the coloring notion used in [2], are testable, showing that this approach can broaden the understanding of the nature of the testable graph properties. The proof combines some generalizations of the methods used in [2] with additional methods.
Stochastic Grammatical Inference of Text Database Structure
Authors: Matthew Young-Lai, Frank Wm. Tompa
Venue: Machine Learning (2000)

For a document collection in which structural elements are identified with markup, it is often necessary to construct a grammar retrospectively that constrains element nesting and ordering. This has been addressed by others as an application of grammatical inference. We describe an approach based on stochastic grammatical inference which scales more naturally to large data sets and produces models with richer semantics. We adopt an algorithm that produces stochastic finite automata and describe modifications that enable better interactive control of results. Our experimental evaluation uses four document collections with varying structure.
An Integrated Approach to Image Watermarking and JPEG-2000 Compression
Authors: Po-Chyi Su, Houng-Jyh Mike Wang, C.-C. Jay Kuo
Venue: Journal of VLSI Signal Processing Systems (2001)

A scheme which integrates image compression and image watermarking in an effective way is proposed in this research. The image compression scheme under consideration is EBCOT (Embedded Block Coding with Optimized Truncation) which has been adopted in the verification model (VM) of the emerging JPEG-2000 image compression standard. The watermark is embedded during the process when the compressed bit-stream is formed, and can be detected on the fly in image decoding. Thus, watermark embedding and retrieval can be done very efficiently in comparison with other existing watermarking schemes. In addition to efficiency, the proposed scheme has many interesting features. The embedded watermark is robust against various signal processing attacks such as coding and filtering while the watermarked image maintains good perceptual quality. The watermark retrieval procedure does not require the knowledge of the original image. Furthermore, the watermark can be detected progressively and region of interest (ROI) watermarking can be accomplished easily.
An experimental study on the role of touch in shared virtual environments
Authors: Cagatay Basdogan, Chih-Hao Ho, Mandayam A. Srinivasan, Mel Slater
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (2000)

Investigating virtual environments has become an increasingly interesting research topic for engineers, computer and cognitive scientists, and psychologists. Although there have been several recent studies focused on the development of multimodal virtual environments (VEs) to study human-machine interactions, less attention has been paid to human-human and human-machine interactions in shared virtual environments (SVEs), and to our knowledge, no attention paid at all to what extent the addition of haptic communication between people would contribute to the shared experience. We have developed a multimodal shared virtual environment and performed a set of experiments with human subjects to study the role of haptic feedback in collaborative tasks and whether haptic communication through force feedback can facilitate a sense of being and collaborating with a remote partner. The study concerns a scenario where two participants at remote sites must cooperate to perform a joint task in an SVE. The goals of the study are (1) to assess the impact of force feedback on task performance, (2) to better understand the role of haptic communication in human-human interactions, (3) to study the impact of touch on the subjective sense of collaborating with a human as reported by the participants based on what they could see and feel, and (4) to investigate if gender, personality, or emotional experiences of users can affect haptic communication in SVEs. The outcomes of this research can have a powerful impact on the development of next-generation human-computer interfaces and network protocols that integrate touch and force feedback technology into the internet, development of protocols and techniques for collaborative teleoperation such as hazardous material removal, space station.