ppxscal/embedding_network huggingface dataset:
A Decompositional Approach to the Design of Parallel Programs
Authors: Ying Liu, Ambuj K. Singh, Rajive L. Bagrodia
Venue: IEEE Transactions on Software Engineering (1994)

A methodology for the derivation of parallel implementations from program specifications is developed. The goal of the methodology is to decompose a program specification into a collection of module specifications via property refinement, such that each module may be implemented independently by a subprogram. The correctness of the implementation is then deduced from the correctness of the property refinement procedure and the correctness of the individual subprograms. The refinement strategy is based on identifying frequently occurring control structures such as sequential composition and iteration. The methodology is developed in the context of the UNITY logic and the UC programming language, and illustrated through the solution of diffusion aggregation in fluid flow simulations.
Is your computing environment secure?: security problems with interrupt handling mechanisms
Authors: Ping Hu, Bruce Christianson
Venue: ACM SIGOPS Operating Systems Review (1995)

In an open distributed system, resources must be shared among various users. Security is one of the major issues in designing such a system. When a computer system is connected to a network, it is very important to ensure that the computer has the ability to manage its local resources securely. In this position paper, we will demonstrate that current computer architectures do give malicious users ways to penetrate computer systems and hence access the system or other user's secrets which are supposed to be well protected. We also propose some possible solutions to counterattack such security threats either at hardware or software level. The impacts of our countermeasures to system hardware and software are also discussed.
XMovie: architecture and implementation of a distributed movie system
Authors: Ralf Keller, Wolfgang Effelsberg, Bernd Lamparter
Venue: ACM Transactions on Information Systems (TOIS) (1995)

We describe a system for storing, transmitting, and presenting digital movies in a computer network. The hardware used in the system is standard hardware, as found in typical workstations today; no special hardware is required, but if available it can be used to provide better performance. The XMovie system has several innovative features. First, it contains a new algorithm for the gradual adaptation of the color lookup table during the presentation of the movie to ensure optimal color quality on low-end workstations. Second, it is a multistandard system supporting the compression techniques MPEG, Motion JPEG, and a newly developed extension to the well-known Color Cell Compression method. Third, it contains AdFEC, a new adaptable forward error correction method for our movie transmission protocol.
Self-similarity in World Wide Web traffic: evidence and possible causes
Authors: Mark E. Crovella, Azer Bestavros
Venue: Proceedings of the 1996 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1996)

Recently the notion of self-similarity has been shown to apply to wide-area and local-area network traffic. In this paper we examine the mechanisms that give rise to the self-similarity of network traffic. We present a hypothesized explanation for the possible self-similarity of traffic by using a particular subset of wide area traffic: traffic due to the World Wide Web (WWW). Using an extensive set of traces of actual user executions of NCSA Mosaic, reflecting over half a million requests for WWW documents, we examine the dependence structure of WWW traffic. While our measurements are not conclusive, we show evidence that WWW traffic exhibits behavior that is consistent with self-similar traffic models. Then we show that the self-similarity in such traffic can be explained based on the underlying distributions of WWW document sizes, the effects of caching and user preference in file transfer, the effect of user "think time", and the superimposition of many such transfers in a local area network. To do this we rely on empirically measured distributions both from our traces and from data independently collected at over thirty WWW sites.
Automatic stochastic tagging of natural language texts
Authors: Evangelos Dermatas, George Kokkinakis
Venue: Computational Linguistics (1995)

Five language and tagset independent stochastic taggers, handling morphological and contextual information, are presented and tested in corpora of seven European languages (Dutch, English, French, German, Greek, Italian and Spanish), using two sets of grammatical tags; a small set containing the eleven main grammatical classes and a large set of grammatical categories common to all languages. The unknown words are tagged using an experimentally proven stochastic hypothesis that links the stochastic behavior of the unknown words with that of the less probable known words. A fully automatic training and tagging program has been implemented on an IBM PC-compatible 80386-based computer. Measurements of error rate, time response, and memory requirements have shown that the taggers' performance is satisfactory, even though a small training text is available. The error rate is improved when new texts are used to update the stochastic model parameters.
A comparative analysis of partial order planning and task reduction planning
Authors: Subbarao Kambhampati
Venue: ACM SIGART Bulletin (1995)

Although task reduction (HTN) planning historically preceded partial order (PO) planning, and is believed to be more general than the latter, very little comparative analysis of the two planning formalisms has been done. Part of the reason for this has been the lack of systematic understanding of the functionalities provided by HTN planning over and above that of partial order planning. In this paper I will describe a generalized algorithm template for partial order planning based on refinement search, and extend it to cover HTN planning. I will use this framework as a basis to (i) discuss the similarities and differences between the HTN and the partial order planning methods, (ii) critically examine the claims regarding the efficiency and expressiveness of HTN planning, and (iii) shed light on several of the less understood features of HTN planning.
An overview of HI-MASS (Hierarchical Modeling and Simulation System)
Authors: Douglas G. Fritz, Robert G. Sargent, Thorsten Daum
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The Hierarchical Modeling and Simulation System (HI-MASS) is a prototype modeling and simulation system that supports modeling based on the Hierarchical Control Flow Graph Model paradigm and simulation execution using a sequential synchronous simulation algorithm. The prototype is an object oriented C++ based system designed for a Unix environment and implemented using freely available software tools. Models are specified using two complementary hierarchical model specification structures, one to specify the components which comprise a model and how those components are interconnected, and the other to specify the behaviors of the individual components. A graphical user interface provides for component and interconnection specification using visual interactive modeling. Behavior specifications are constructed using C++ classes and functions provided by HI-MASS.
Protocol implementation using integrated layer processing
Authors: Torsten Braun, Christophe Diot
Venue: ACM SIGCOMM Computer Communication Review (1995)

Integrated Layer Processing (ILP) is an implementation concept which "permit[s] the implementor the option of performing all the [data] manipulation steps in one or two integrated processing loops" [1]. To estimate the achievable benefits of ILP a file transfer application with an encryption function on top of a user-level TCP has been implemented and the performance of the application in terms of throughput and packet processing times has been measured. The results show that it is possible to obtain performance benefits by integrating marshalling, encryption and TCP checksum calculation. They also show that the benefits are smaller than in simple experiments, where ILP effects have not been evaluated in a complete protocol environment. Simulations of memory access and cache hit rate show that the main benefit of ILP is reduced memory accesses rather than an improved cache hit rate. The results further show that data manipulation characteristics may significantly influence the cache behavior and the achievable performance gain of ILP.
Correct Architecture Refinement
Authors: Mark Moriconi, Xiaolei Qian, R. A. Riemenschneider
Venue: IEEE Transactions on Software Engineering (1995)

A method is presented for the stepwise refinement of an abstract architecture into a relatively correct lower level architecture that is intended to implement it. A refinement step involves the application of a predefined refinement pattern that provides a routine solution to a standard architectural design problem. A pattern contains an abstract architecture schema and a more detailed schema intended to implement it. The two schemas usually contain very different architectural concepts (from different architectural styles). Once a refinement pattern is proven correct, instances of it can be used without proof in developing specific architectures. Individual refinements are compositional, permitting incremental development and local reasoning. A special correctness criterion is defined for the domain of software architecture, as well as an accompanying proof technique. A useful syntactic form of correct composition is defined. The main points are illustrated by means of familiar architectures for a compiler. A prototype implementation of the method has been used successfully in a real application.
Region Competition: Unifying Snakes, Region Growing, and Bayes/MDL for Multiband Image Segmentation
Authors: Song Chun Zhu, Alan Yuille
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

We present a novel statistical and variational approach to image segmentation based on a new algorithm named region competition. This algorithm is derived by minimizing a generalized Bayes/MDL criterion using the variational principle. The algorithm is guaranteed to converge to a local minimum and combines aspects of snakes/balloons and region growing. Indeed the classic snakes/balloons and region growing algorithms can be directly derived from our approach. We provide theoretical analysis of region competition including accuracy of boundary location, criteria for initial conditions, and the relationship to edge detection using filters. It is straightforward to generalize the algorithm to multiband segmentation and we demonstrate it on gray level images, color images and texture images. The novel color model allows us to eliminate intensity gradients and shadows, thereby obtaining segmentation based on the albedos of objects. It also helps detect highlight regions.
Supporting Fault-Tolerant Parallel Programming in Linda
Authors: David Edward Bakken, Richard D. Schlichting
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

Linda is a language for programming parallel applications whose most notable feature is a distributed shared memory called tuple space. While suitable for a wide variety of programs, one shortcoming of the language as commonly defined and implemented is a lack of support for writing programs that can tolerate failures in the underlying computing platform. This paper describes FT-Linda, a version of Linda that addresses this problem by providing two major enhancements that facilitate the writing of fault-tolerant applications: stable tuple spaces and atomic execution of tuple space operations. The former is a type of stable storage in which tuple values are guaranteed to persist across failures, while the latter allows collections of tuple operations to be executed in an all-or-nothing fashion despite failures and concurrency. The design of these enhancements is presented in detail and illustrated by examples drawn from both the Linda and fault-tolerance domains. An implementation of FT-Linda for a network of workstations is also described. The design is based on replicating the contents of stable tuple spaces to provide failure resilience and then updating the copies using atomic multicast. This strategy allows an efficient implementation in which only a single multicast message is needed for each atomic collection of tuple space operations.Index Terms¿Parallel programming, fault-tolerance, Linda, atomic execution, stable storage, atomic multicast.
Identifying loops using DJ graphs
Authors: Vugranam C. Sreedhar, Guang R. Gao, Yong-Fong Lee
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1996)

Loop identification is a necessary step in loop transformations for high-performance architectures. One classical technique for detecting loops is Tarjan's interval-finding algorithm. The intervals identified by Tarjan's method are single-entry, strongly connected subgraphs that closely reflect a program's loop structure. We present a simple algorithm for identifying both reducible and irreducible loops using DJ graphs. Our method is a generalization of Tarjan's method, as it identifies nested intervals (or loops) even in the presence of irreducibility.
The design of VIP-FS: a virtual, parallel file system for high performance parallel and distributed computing
Authors: Michael Harry, Juan Miguel del Rosario, Alok Choudhary
Venue: ACM SIGOPS Operating Systems Review (1995)

In the past couple of years, significant progress has been made in the development of message-passing libraries for parallel and distributed computing, and in the area of high-speed networking. Both technologies have evolved to the point where programmers and scientists are now porting many applications previously executed exclusively on parallel machines into distributed programs for execution on more readily available networks of workstations. Such advances in computing technology have also led to a tremendous increase in the amount of data being manipulated and produced by scientific and commercial application programs. Despite their popularity, message-passing libraries only provide part of the support necessary for most high performance distributed computing applications --- support for high speed parallel I/O is still lacking.In this paper, we provide an overview of the conceptual design of a parallel and distributed I/O file system, the Virtual Parallel File System (VIP-FS), and describe its implementation. VIP-FS makes use of message-passing libraries to provide a parallel and distributed file system which can execute over multiprocessor machines or heterogeneous network environments.
Intrinsic dynamics and pharmacometric model discrimination
Authors: Meyer Katzper
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Comparison of two competing pharmacometric models is undertaken using graphic representations to elucidate their similarities and differences. The effect compartment model and the indirect response model are simulated and compared for a range of parameters to determine to what extent their dynamic characteristics can be matched. Visual tools such as hysteresis curves are used to examine model dynamics in a variety of ways. Differentiation is facilitated to the extent that competing models have distinctly defined dynamics. For the models studied, the degree of difference depends on the region in parameter space which in turn relates to clinical response.
CSCW: an opportunity for action research
Authors: Richard W. Collins
Venue: Proceedings of conference on Organizational computing systems (1995)

Computer-supported cooperative work(CSCW) technologies are being tried as part of complex projects. This paper describes a recent failed attempt at using CSCW technology by two organizations as part of a new product development project. Reasons for the failure are examined. The importance of organizational culture in the success or failure of CSCW is discussed. Approaching future research using the action research model from the organizational development field is proposed.
Principled disambiguation: discriminating adjective senses with modified nouns
Authors: John S. Justeson, Slava M. Katz
Venue: Computational Linguistics (1995)

Recent corpus-based work on word sense disambiguation explores the application of statistical pattern recognition procedures to lexical co-occurrence data from very large text databases. In this paper we argue for a linguistically principled approach to disambiguation, in which relevant contextual clues are narrowly defined, in syntactic and semantic terms, and in which only highly reliable clues are exploited. Statistical methods play a definite role in this work, helping to organize and analyze data, but the disambiguation method itself does not employ statistical data or decision criteria. This approach results in improved understanding of the disambiguation problem both in general and on a word-specific basis and leads to broadly applicable and nearly errorless clues to word sense. The approach is illustrated by an experiment discriminating among the senses of adjectives, which have been relatively neglected in work on sense disambiguation. In particular, the paper assesses the potential of nouns for discriminating among the senses of adjectives that modify them. This assessment is based on an empirical study of five of the most frequent ambiguous adjectives in English: hard, light, old, right, and short. About three-quarters of all instances of these adjectives can be disambiguated almost errorlessly by the nouns they modify or by the syntactic constructions in which they occur. Such disambiguation requires only simple rules, which can be automated easily. Furthermore, a small number of semantic attributes supply a compact means of representing the noun clues in a very few rules. Clues other than nouns are required when modified nouns are not useable. The sense of an ambiguous modified noun may be needed to determine the relevant semantic attribute for disambiguation of a target adjective; and other adjectives, verbs, and grammatical constructions all show evidence of high reliability, and sometimes of high applicability, when they stand in specific, well-defined syntactic relations to the ambiguous adjective. Some of these clues, however, may be hard to automate.
A case study in parallel scientific computing: the boundary element method on a distributed-memory multiprocessor
Authors: Ramesh Natarajan, Dilip Krishnaswamy
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

The Boundary Element Method is a widely-used discretization technique for solving boundary-value problems in engineering analysis. The solution of large problems by this method is limited by the storage and computational requirements for the generation and solution of large matrix systems resulting from the discretization. We discuss the implementation of these computations on the IBM SP-2 distributed-memory parallel computer, for applications involving the 3DD Laplace and Helmholtz equations.
Lecture supporting system by using e-mail and WWW
Authors: Tomohiro Nishida, Akinori Saitoh, Yoshihiro Tsujino, Nobuki Tokura
Venue: ACM SIGCSE Bulletin (1996)

We have developed a system to support communication between students and teachers on the computer network. By using e-mail, they can exchange information, e.g., questions and reports whenever and wherever they can access the Internet. And by using World Wide Web, the teacher can provide impressive teaching material for the student. Moreover the system provides "easy maintenance" facilities. So the teachers who use it don't have to master the details of the system. They can use it easily by following various navigational information instructions. And to use the system for many years, it can reuse information and setups which were made previously.
Timed protocol verification for Estelle-specified protocols
Authors: Chung-Ming Huang, Shiun-Wei Lee
Venue: ACM SIGCOMM Computer Communication Review (1995)

This paper presents a new model, which is named Timed Communicating State Machine (TCSM), for specifying protocols that incorporate timed properties as part of their specifications. The TCSM model is similar to the Extended Communicating Finite State Machine (ECFSM) model. The major extension is providing an additional mechanism, i.e., a time interval attribute, for describing the timed properties. We also propose the corresponding formal TCSM-based timed verification scheme, i.e., a new timed global state reachability analysis. In the new timed global state reachability analysis, the exploration is decided by the predicate, the time relationships, and/or the input event. Using the TCSM model and the timed verification scheme, an Estelle-based Timed Protocol Verification System (ETPVS) has been developed on SUN SPARC workstations. In this way, timed protocols can be formally specified in Estelle and can also be verified using ETPVS.
TCP/IP illustrated (vol. 2): the implementation
Authors: W. Richard Stevens Gary R. Wright
Venue:  (1995)

TCP/IP Illustrated, Volume 2 contains a thorough explanation of how TCP/IP protocols are implemented. There isn't a more practical or up-to-date bookothis volume is the only one to cover the de facto standard implementation from the 4.4BSD-Lite release, the foundation for TCP/IP implementations run daily on hundreds of thousands of systems worldwide.Combining 500 illustrations with 15,000 lines of real, working code, TCP/IP Illustrated, Volume 2 uses a teach-by-example approach to help you master TCP/IP implementation. You will learn about such topics as the relationship between the sockets API and the protocol suite, and the differences between a host implementation and a router. In addition, the book covers the newest features of the 4.4BSD-Lite release, including multicasting, long fat pipe support, window scale, timestamp options, and protection against wrapped sequence numbers, and many other topics.Comprehensive in scope, based on a working standard, and thoroughly illustrated, this book is an indispensable resource for anyone working with TCP/IP.
Comparing data modeling formalisms
Authors: Young-Gul Kim, Salvatore T. March
Venue: Communications of the ACM (1995)

Accurate specification and validation of information requirements is critical to the development of organizational information systems. Semantic data models were developed to provide a precise and unambiguous representation of organizational information requirements [9, 17]. They serve as a communication vehicle between analysts and users. After analyzing 11 semantic data models, Biller and Neuhold [3] conclude that there are essentially only two types of data modeling formalisms: entity-attribute-relationship (EAR) models and object-relationship (OR) models. Proponents of each claim their model yields &ldquo;better&rdquo; representations [7] than the other. There is, however, little empirical evidence to substantiate these claims.
Hadamard Matrices and Dihedral Groups
Authors: Hiroshi Kimura
Venue: Designs, Codes and Cryptography (1996)

Let D_{2p} be a dihedral group of order 2p, where p is an odd integer. Let ZD_{2p} be the group ring of D_{2p} over the ring Z of integers. We identify elements of ZD_{2p} and their matrices of the regular representation of ZD_{2p}. Recently we characterized the Hadamard matrices of order 28 (Kimura:hall and Kimura:nonhall). There are exactly 487 Hadamard matrices of order 28, up to equivalence. In these matrices there exist matrices with some interesting properties. That is, these are constructed by elements of ZD_{6}. We discuss relation of ZD_{2p} and Hadamard matrices of order n=8p+4, and give some examples of Hadamard matrices constructed by dihedral groups.