ppxscal/embedding_network huggingface dataset:
A Validity Measure for Fuzzy Clustering
Authors: Xuanli Lisa Xie, Gerardo Beni
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

The authors present a fuzzy validity criterion based on a validity function which identifies compact and separate fuzzy c-partitions without assumptions as to the number of substructures inherent in the data. This function depends on the data set, geometric distance measure, distance between cluster centroids and more importantly on the fuzzy partition generated by any fuzzy algorithm used. The function is mathematically justified via its relationship to a well-defined hard clustering validity function, the separation index for which the condition of uniqueness has already been established. The performance of this validity function compares favorably to that of several others. The application of this validity function to color image segmentation in a computer color vision system for recognition of IC wafer defects which are otherwise impossible to detect using gray-scale image processing is discussed.
Generosity helps, or an 11&ndash;competitive algorithm for three servers
Authors: Marek Chrobak, Lawrence L. Larmore
Venue: Proceedings of the third annual ACM-SIAM symposium on Discrete algorithms (1992)

We propose a new algorithm called Equipoise for the k-server problem, and we prove that it is 2-competitive for two servers and 11-competitive for three servers. For k=3, this is a tremendous improvement over previously known constants. The algorithm uses several techniques for designing on-line algorithms - convex hulls, work functions and forgiveness. The results presented in this paper were earlier announced at the DIMACS Workshop on On-Line Algorithms [8].
Working with audio: integrating personal tape recorders and desktop computers
Authors: Leo Degen, Richard Mander, Gitta Salomon
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

Audio data is rarely used on desktop computers today, although audio is otherwise widely used for communication tasks. This paper describes early work aimed at creating computer tools that support the ways users may want to work with audio data. User needs for the system were determined by intervieweing people already working with audio data, using existing devices such as portable tape recorders. A preliminary prototype system &ndash; consisting of a personal tape recorder for recording and simultaneously marking audio and a Macintosh application for browsing these recordings &ndash; was built. Informal field user tests of this prototype system have indicated areas for improvement and directions for future work.
A Continuous Media I/O Server and Its Synchronization Mechanism
Authors: David P. Anderson, George Homsy
Venue: Computer (1991)

Acme, a network server for digital audio and video I/O, is presented. Acme lets users specify their synchronization requirements through an abstraction called a logical time system. The nature of logical time systems is discussed, some examples are given, and their implementation is addressed.
Connections with multiple congested gateways in packet-switched networks part 1: one-way traffic
Authors: Sally Floyd
Venue: ACM SIGCOMM Computer Communication Review (1991)

In this paper we explore the bias in TCP/IP networks against connections with multiple congested gateways. We consider the interaction between the bias against connections with multiple congested gateways, the bias of the TCP window modification algorithm against connections with longer roundtrip times, and the bias of Drop Tail and Random Drop gateways against bursty traffic. Using simulations and a heuristic analysis, we show that in a network with the window modification algorithm in 4.3 tahoe BSD TCP and with Random Drop or Drop Tail gateways, a longer connection with multiple congested gateways can receive unacceptably low throughput. We show that in a network with no bias against connections with longer roundtrip times and with no bias against bursty traffic, a connection with multiple congested gateways can receive an acceptable level of throughput.We discuss the application of several current measures of fairness to networks with multiple congested gateways, and show that different measures of fairness have quite different implications. One view is that each connection should receive the same throughput in bytes/second, regardless of roundtrip times or numbers of congested gateways. Another view is that each connection should receive the same share of the network's scarce congested resources. In general, we believe that the fairness criteria for connections with multiple congested gateways requires further consideration.
Domain description grammar: application of linguistic semantics
Authors: R. P. Carasik, S. M. Johnson, D. A. Patterson, G. A. Von Glahn
Venue: ACM SIGSOFT Software Engineering Notes (1990)

Domain descriptions should represent more than the characteristics of data and the operations on it. They should be "semantic" in the sense that they may represent information such as the meanings of special terms used in the business, as well as goals and rules. ER models are often described as "semantic data models". However, the correspondence between ER and natural language is through syntactic rather than through semantic constructs. Conceptual modeling languages and knowledge representation techniques are more appropriate for representing domain meaning. Modern research in linguistics, semantics, and artificial intelligence provides valuable insight into basic issues regarding such representations. Domain descriptions must use languages based on generally-accepted linguistic and knowledge representation principles.
Design for fast DSP machine
Authors: Robert McLaughlin
Venue: ACM SIGARCH Computer Architecture News (1990)

In the following we propose a design for a parallel machine for GHz rate general application Digital Signal Processing, DSP.
Picking reference events from tense trees: a formal, implementable theory of English tense-aspect semantics
Authors: Lenhart K. Schubert, Chung Hee Hwang
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

Despite numerous investigations into English tense-aspect semantics, the problem of formally interpreting tense and aspect remains in large part unsolved. A formal solution requires (a) a well-defined mapping from a subset of English covering the most common tense-aspect constructions (including embedded tensed clauses) to a formal meaning representation, and (b) a well-defined denotational semantics for the meaning representation, which accords with speakers' intuitions about the original text. We propose a simple structure called a <i>tense tree</i> (or a set of connected tense trees) as a basis for interpreting tense-aspect constructions and some time adverbials in a context-dependent way. The de-indexicalization process simultaneously transforms tense trees and logical forms, the former in accord with simple recursion equations and the latter in accord with formal equivalences between context-indexed and context-independent logical forms. The rules have been implemented, and yield meaning representations in a formal episodic logic for narrative understanding.
The Turing Test is not a trick: Turing indistinguishability is a scientific criterion
Authors: Stevan Harnad
Venue: ACM SIGART Bulletin (1992)

It is important to understand that the Turing Test (TT) is not, nor was it intended to be, a trick; how well one can fool someone is not a measure of scientific progress. The TT is an empirical criterion: It sets AI's empirical goal to be to generate human scale performance capacity. This goal will be met when the candidate's performance is totally indistinguishable from a human's. Until then, the TT simply represents what it is that AI must endeavor eventually to accomplish scientifically.
A gridless router for industrial design rules
Authors: W. L. Schiele, Th. Krüger, K. M. Just, F. H. Kirsch
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

A point-to-point routing algorithm with three new features is presented. First, the router makes optimal use of oversized, rectangular contacts. Second, it allows different wire width on different layers, with the layers having complete freedom as to routing direction. These two features make the algorithm attractive for MOS layout applications. Finally it is able to realize all-angle routing and to accept all-angle obstacles, a feature interesting for hybrid and PCB routing. The router is gridless and guarantees a solution if one exists. Since it is based on computational geometry algorithms, it offers a low run-time complexity. The ideas have been implemented in a prototype version for 45&deg; routing. The results indicate that the router performs well, even on large designs.
A denotational semantics for the Starburst production rule language
Authors: Jennifer Widom
Venue: ACM SIGMOD Record (1992)

Researchers often complain that the behavior of database production rules is difficult to reason about and understand, due in part to the lack of formal declarative semantics. It has even been claimed that database production rule languages inherently cannot be given declarative semantics, in contrast to, e.g., deductive database rule languages. In this short paper we dispute this claim by giving a denotational semantics for the Starburst database production rule language.
LECSIM: a levelized event driven compiled logic simulation
Authors: Zhicheng Wang, Peter M. Maurer
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

LECSIM is a highly efficient logic simulator which integrates the advantages of event driven interpretive simulation and levelized compiled simulation. Two techniques contribute to the high efficiency. First it employs the zero-delay simulation model with levelized event scheduling to eliminate most unnecessary evaluations. Second, it compiles the central event scheduler into simple local scheduling segments which reduces the overhead of event scheduling. Experimental results show that LECSIM runs about 8-77 time faster than traditional unit-delay event-driven interpretive simulator. LECSIM also provides the option of scheduling with respect to individual gates or with respect to fan-out free blocks. When the circuit is partitioned into fan-out free blocks, the speed increases by a factor of 2-3. With partitioning, the speed of LECSIM is only about 1.5-3.4 times slower than a levelized compiled simulation for the combinational circuits we have tested.
Comments on 'Design and Analysis of Arbitration Protocols' by F. El Guibaly
Authors: Barry Wilkinson
Venue: IEEE Transactions on Computers (1992)

In the above-titled paper by F. El Guibaly, the access time for various arbitration protocols was theoretically characterized. The commenter uses simulations to investigate single-bus multiprocessor arbitration protocols. Differences are found between the theoretical results and the simulation results. Theoretical formulae given by El Guibaly are corrected and modified to take into account that resubmitted requests increase the request rate. Closer agreement between theoretical and simulation results is then obtained.
Generating parallel code for SIMD machines
Authors: Bruce McKenney, Boleslaw K. Szymanski
Venue: ACM Letters on Programming Languages and Systems (LOPLAS) (1992)

Massively parallel SIMD machines rely on data parallelism usually achieved by a careful hand coding to support program efficiency. This paper describes parallelization of code generated for SIMD machines by the compiler for the Equational Programming Language, EPL. The language supports architecture-independent scientific programming by recurrent equations. The EPL compiler serves as a programming aid for users of parallel machines by automating data partitioning and computation parallelization based on inherent data dependencies. In support of a Connection Machine architecture, the EPL compiler performs horizontal partitioning of the program, a process that selects a dimension of each data structure to be projected along the processor array. Each processor then holds a single instance of that structure and operations along the projected dimension are done in parallel. The paper describes horizontal partitioning, code generation in MPL and efficiency of programs generated for Maspar SIMD machine.
Instruction-level parallelism in Prolog: analysis and architectural support
Authors: Alessandro De Gloria, Paolo Faraboschi
Venue: ACM SIGARCH Computer Architecture News (1992)

The demand of increasing computation power for symbolic processing has given a strong impulse to the development of ASICs dedicated to the execution of prolog. Unlike past microcoded implementation based on the Warren machine model, novel trends in high performance Prolog processors suggest the implementation of RISC-based processors committed to prolog only through the adoption of a few basic dedicated features, like the Berkeley Abstract Machine (BAM) processor. Following the idea of using a smart compiler for a simple instruction set, the SYMBOL project represents an experiment in applying global compaction techniques and VLIW design philosophy to the static exploitation of instruction-level parallelism in Prolog. This paper presents code analysis results and shows how we can approach the theoretical speed-up limit (about 3) imposed by Amdahl's law on shared memory models, by means of global code optimizations and a suitable architectural support. In addition, we show implementation details and some preliminary data of a VLSI prototype architecture.
Pipeline Design Tradeoffs in a 32-bit Gallium Arsenide Microprocessor
Authors: Veljko M. Milutinovic, David A. Fura, Walter A. Helbig
Venue: IEEE Transactions on Computers (1991)

The results of a study of the instruction pipeline design for a 32-b single-chip GaAs microprocessor are presented. The authors introduce nine candidate solutions for the instruction pipeline, define a set of technology-dependent and application-related parameters, and present the results of the comparative performance evaluation. Important differences between GaAs and silicon, which are relevant for the design of an instruction pipeline, are described. The authors determine the quantitative differences between various candidate solutions. The superb performance of the pipelined memory pipeline in all environments is demonstrated.
P3D: a Lisp-based format for representing general 3D models
Authors: Joel Welling, Chris Nuuja, Phil Andrews
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

The visualization of scientific data requires the translation of that data into a format suitable for rendering. As the number of supercomputing simulations and the number of available renderers increases, the magnitude of this translation problem increases as well. A potential solution is the use of a standard format for 3D models, which (ideally) all simulations can generate and all renderers render. The P3D model metafile is such a format, based upon Common Lisp with extensions for geometry. This method provides easy representation of directed acyclic graphs and complete programmability to facilitate interfaces to new model generators, without the introduction of a new and unfamiliar language.
Efficient algorithms for the Hitchcock transportation problem
Authors: Takeshi Tokuyama, Jun Nakano
Venue: Proceedings of the third annual ACM-SIAM symposium on Discrete algorithms (1992)

We consider the Hitchcock transportation problem on n supply points and k demand points when n is much greater than k. The problem is solved in O(n2k log n + n2 log2 n) time if n > k log k. Further, applying a geometric method named splitter finding and randomization, we improve the time complexity for a case in which the ratio c of the least supply and the maximum supply satisfies the inequality log cn < n/k4 log n. Indeed, if n < k5 log3 k and c = poly(n), the problem is solved in O(kn) time, which is optimal.
On the complexity of global computation in the presence of link failures: the case of uni-directional faults
Authors: Oded Goldreich, Dror Sneh
Venue: Proceedings of the eleventh annual ACM symposium on Principles of distributed computing (1992)

We consider distributed computations in an asynchronous communication model with undetectable link failures. The computational tasks we consider are obtaining the value of a predetermined function of the local inputs scattered in the network (e.g., the sum of all local values). We call this task Global Computation. A trivial protocol for Global Computation consists of each processor sending its local input to all processors via flooding. Our aim is to justify the use of this simple protocol, in the presence of faulty links, by proving matching lower bounds on the message complexity (i.e., total number of messages sent) of Global Computation. In this paper we concentrate on the case in which the communication links are either unidirectional or fail in a uni-directional manner. Our main result states that for every n and m, the message complexity of Global Computation on such networks is at least n.m/PolyLog (n) where n is the number of processors and m is the number of links. Hence, in the presence of unidirectional link failures, the simple flooding algorithm is optimal up to a polylogarithmic factor.
Manchester data-flow: a progress report
Authors: J. R. Gurd, D. F. Snelling
Venue: Proceedings of the 6th international conference on Supercomputing (1992)

The Manchester Data-Flow Machine, MDFM, has evolved continuously during the past decade. By the time the prototype uniprocessor hardware system was decommissioned, in 1989, the putative multi-processor architecture comprised separate Processing Elements and Structure Store Units, together with a &ldquo;global&rdquo; Allocator and Throttle Unit, all linked by a packet-based Interconnection Switch. The decisions leading to this design are well documented in the literature, but some of the reasoning behind these decisions is now out-of-date. This paper looks afresh at the MDFM architecture, in the light of new hardware and software technology and the new state-of-the-art in data-flow computing, and derives an updated architecture, NMDFM, for a Manchester-style multi-processor system. The variable parameters of the NMDFM are investigated in an attempt to find an &ldquo;optimum&rdquo; set for future simulation studies.
A dynamic language model for speech recognition
Authors: F. Jelinek, B. Merialdo, S. Roukos, M. Strauss
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

In the case of a trigram language model, the probability of the next word conditioned on the previous two words is estimated from a large corpus of text. The resulting static trigram language model (STLM) has fixed probabilities that are independent of the document being dictated. To improve the language model (LM), one can adapt the probabilities of the trigram language model to match the current document more closely. The partially dictated document provides significant clues about what words are more likely to be used next. Of many methods that can be used to adapt the LM, we describe in this paper a simple model based on the trigram frequencies estimated from the partially dictated document. We call this model a cache trigram language model (CTLM) since we are caching the recent history of words. We have found that the CTLM reduces the perplexity of a dictated document by 23%. The error rate of a 20,000-word isolated word recognizer decreases by about 5% at the beginning of a document and by about 24% after a few hundred words.
Reducing the latency of a real-time garbage collector
Authors: Ralph E. Johnson
Venue: ACM Letters on Programming Languages and Systems (LOPLAS) (1992)

This paper shows how to make the latency of scanning a page in the Appel-Ellis-Li real-time garbage collector be proportional only to the number of object references on a page (the page size), instead of to the sum of the sizes of the objects referenced by the page. This makes the garbage collection algorithm much more suitable for real-time systems.
An empty exercise
Authors: Carl de Boor
Venue: ACM SIGNUM Newsletter (1990)

The exercise in question concerns the rules which should govern the treatment of empty matrices in a matrix-oriented computing environment like MATLAB. This provides students of Linear Algebra with an unusual test of their understanding of the standard definitions and rules governing matrices.
Experience with mean value analysis model for evaluating shared bus, throughput-oriented multiprocessors
Authors: Mee-Chow Chiang, Gurindar S. Sohi
Venue: ACM SIGMETRICS Performance Evaluation Review (1991)

We report on our experience with the accuracy of mean value analysis analytical models for evaluating shared bus multiprocessors operating in a throughput-oriented environment. Having developed separate models for multiprocessors with circuit switched and split transaction, pipelined (packet switched) buses, wc compare the results of the models with those of an actual trace-driven simulation for 5,376 multiprocessor configurations.We find that the analytical models are accurate in predicting the individual processor throughputs and partial bus utilizations. For processor throughput, the difference between the results of the models and simulation are within 1% for 75% of the cases and within 3% in 94% of all cases. For partial bus utilization the model results are with 1% of simulation results in 70% of all cases and within 3% in 92% of all cases. The models are less accurate in predicting cache miss latency.
A new language for multicomputer programming
Authors: José M. García Carrasco
Venue: ACM SIGPLAN Notices (1992)

In this paper we present an extension of the Pascal language: the Distributed Pascal, suitable for MIMD computers with message-passing. This extension is simple, elegant, flexible and powerful. This language is very suited for numerical algorithms. A complex mathematical algorithm is shown as an example of this. Up to date, we have developed the compiler's front-end and we are running a program in this language by means of simulation.
On a general framework for large-scale constraint-based optimization
Authors: Jun Gu
Venue: ACM SIGART Bulletin (1991)

The explicit solution for the n ndash;queens problem, mentioned in a letter from Bo Bernhardsson [2], is basically Pauls's solution analyzed by Ahrens (See reference [1] of our previous article in SIGART October issue 1990). The result was in public domain long before 1918 (not 1969). We also mentioned its weakness, namely: The class of solutions provided by analytical methods is very restricted, as Ahrens pointed out in [1]. They can only provide one solution for the n ndash;queens problem and can not provide any solution (much better explicit solutions for the n ndash;queens problem exist). This is not the case for search methods which can find, in principle, any solution. This distinction is crucial for practical applications of the n-queens problem.