ppxscal/embedding_network huggingface dataset:
Delay Optimization of Carry-Skip Adders and Block Carry-Lookahead Adders Using Multidimensional Dynamic Programming
Authors: Pak K. Chan, Martine D. F. Schlag, Clark D. Thomborson, Vojin G. Oklobdzija
Venue: IEEE Transactions on Computers (1992)

The worst-case carry propagation delays in carry-skip adders and block carry-lookahead adders depend on how the full adders are grouped structurally together into blocks as well as the number of levels. The authors report on a multidimensional dynamic programming paradigm for configuring these two adders to attain minimum latency. Previous methods are applicable only to very limited delay models that do not guarantee a minimum latency configuration. Under the delay model, critical path delay is calculated not only taking into account the intrinsic gate delays, but also the fanin and fanout contributions.
Fast Division Using Accurate Quotient Approximations to Reduce the Number of Iterations
Authors: Derek Wong, Michael Flynn
Venue: IEEE Transactions on Computers (1992)

A class of iterative integer division algorithms is presented based on look-up table and Taylor-series approximations to the reciprocal. The algorithm iterates by using the reciprocal to find an approximate quotient and then subtracting the quotient multiplied by the divisor from the dividend to find a remaining dividend. Fast implementations can produce an average of either 14 or 27 b per iteration, depending on whether the basic or advanced version of this method is implemented. Detailed analyses are presented to support the claimed accuracy per iteration. Speed estimates using state-of-the-art ECL components show that this method is faster than the Newton-Raphson technique and can produce 53-b quotients of 53-b numbers in about 25 ns using the basic method and 21 ns using the advanced method. In addition, these methods naturally produce an exact remainder, which is very useful for implementing precise rounding specifications.
SPARE: A Development Environment for Program Analysis Algorithms
Authors: G. A. Venkatesh, Charles N. Fischer
Venue: IEEE Transactions on Software Engineering (1992)

A tool that bridges the gap between the theory and practice of program analysis specifications is described. The tool supports a high-level specification language that enables clear and concise expression of analysis algorithms. The denotational nature of the specifications eases the derivation of formal proofs of correctness for the analysis algorithm. SPARE (structured program analysis refinement environment) is based on a hybrid approach that combines the positive aspects of both the operational and the semantics-driven approach. An extended denotational framework is used to provide specifications in a modular fashion. Several extensions to the traditional denotational specification language have been designed to allow analysis algorithms to be expressed in a clear and concise fashion. This extended framework eases the design of analysis algorithms as well as the derivation of correctness proofs. The tool provides automatic implementation for testing purposes.
Accommodating imprecision in database systems: issues and solutions
Authors: Amihai Motro
Venue: ACM SIGMOD Record (1990)

Most database systems are designed under assumptions of precision of both the data stored in their databases, and the requests to retrieve data. In reality, however, these assumptions are often invalid, and in recent years considerable attention has been given to issues of imprecision in database systems. In this paper we review the major solutions for accommodating imprecision, and we describe issues that have yet to addressed, offering possible research directions.
Approximating clique is almost NP-complete (preliminary version)
Authors: U. Feige, S. Goldwasser, L. Lovász, S. Safra, M. Szegedy
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

The computational complexity of approximating omega (G), the size of the largest clique in a graph G, within a given factor is considered. It is shown that if certain approximation procedures exist, then EXPTIME=NEXPTIME and NP=P.
A Performance Study of the ISO Transport Protocol
Authors: Bernd W. Meister
Venue: IEEE Transactions on Computers (1991)

The performance of different implementations of the ISO transport protocol class 4 on top of a connectionless link-layer protocol in the presence of transmission errors is studied by means of simulation. A main goal of the study is to find robust protocol versions yielding good performance for all possible combinations of implementations. The performance measure investigated is the throughput that can be achieved in transferring files between two stations over a local area or long-distance network. The results are compared to those obtained for the ISO transport protocol class 2 on top of a connection-oriented link-layer protocol. It is assumed that data and acknowledgement frames could be lost or corrupted by transmission errors. The results show that, at the sender side, retransmit all always yields higher performance than retransmit first, and, at the receiver side, store results in higher performance than discard.
Towards environment-independent spoken language systems
Authors: Alejandro Acero, Richard M. Stern
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

In this paper we discuss recent results from our efforts to make SPHINX, the CMU continuous-speech speaker-independent recognition system, robust to changes in the environment. To deal with differences in noise level and spectral tilt between close-talking and desk-top microphones, we describe two novel methods based on additive corrections in the cepstral domain. In the first algorithm, an additive correction is imposed that depends on the instantaneous SNR of the signal. In the second technique, EM techniques are used to best match the cepstral vectors of the input utterances to the ensemble of codebook entries representing a standard acoustical ambience. Use of these algorithms dramatically improves recognition accuracy when the system is tested on a microphone other than the one on which it was trained.
A New Framework for Designing and Analyzing BIST Techniques and Zero Aliasing Compression
Authors: Dhiraj K. Pradham, Sandeep K. Gupta
Venue: IEEE Transactions on Computers (1991)

A general framework for shift register-based signature analysis is presented, and a mathematical model for this framework-based on coding theory-is developed. There are two key features of this formulation, first, it allows for uniform treatment of LFSR, MISR, and multiple MISR-based signature analyzer. In addition, using this formulation, a new compression scheme for multiple output CUT is proposed. This scheme, referred to as multiinput LFSR, has the potential to achieve better aliasing than other schemes such as the multiple MISR scheme of comparable hardware complexity. Several results on aliasing are presented, and certain known results are shown to be direct consequences of the formulation. Also developed are error models that take into account the circuit topology and the effect of faults at the outputs. Using these models, exact closed-form expressions for aliasing probability are developed. A closed-form aliasing expression for MISR under an independent error model is provided.
A first step towards an evaluation framework taxonomy
Authors: Peter Kokol
Venue: ACM SIGOIS Bulletin (1991)

A possible evaluation framework taxonomy is presented in this paper. Taxonomy is based on three root definitions derived with the "Checklands Soft System Methodology". According to them we distinguish three main evaluation framework categories: measurement, ranking and taxonomy.
Exploring HCI into the '90s: CHISIG Australia 1990 conference report
Authors: Gitte Lindgaard
Venue: ACM SIGCHI Bulletin (1992)

Australia only rarely enjoys an opportunity to host international conferences, being too many flight hours removed from the mainstream of research activities. However, at this year's annual conference, CHISIG tested one method for overcoming problems of distance. In an effort to add international flavour to the conference program, keynote speakers from outside Australia were deemed a necessary addition to the local content. Yet, operating on a shoestring budget, "importing" live speakers was well beyond our means.
Collection of spontaneous speech for the ATIS domain and comparative analyses of data collected at MIT and TI
Authors: Joseph Polifroni, Stephanie Seneff, Victor W. Zue
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

As part of our development of a spoken language system in the ATIS domain, we have begun a small-scale effort in collecting spontaneous speech data. Our procedure differs from the one used at Texas Instruments (TI) in many respects, the most important being the reliance on an existing system, rather than a wizard, to participate in data collection. Over the past few months, we have collected over 3,600 spontaneously generated sentences from 100 subjects. This paper documents our data collection process, and makes some comparative analyses of our data with those collected at TI. The advantages as well as disadvantages of this method of data collection will be discussed.
MISER: an integrated three layer gridless channel router and compactor
Authors: Roshan Gidwani, Naveed A. Sherwani
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

In this paper, we present a new gridless three layer channel router (MISER) based on an integrated approach to routing and compaction. MISER partitions the input net-list into several sub net-lists called levels and forms a level graph. This level graph is used to guide the routing and compaction process. Compaction is done immediately after each level is routed. Experimental results show that our algorithm usually performs 5-10% better than existing three layer channel routing algorithms.
Data security for object-oriented programming systems based on inference engines (abstract)
Authors: Linda Null, Johnny Wong
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

Protecting data stored in a computer is a difficult task, particularly in a society which has become increasingly dependent on computer systems. This paper focuses on a new model which has been proposed for data security and explores the extension of this model to object-oriented programming systems. The model uses both a trusted filter and an inference engine to provide security in a dynamically changing environment. The filter component protects against Trojan Horse release and direct user release, while the inference engine used rules which specify security constraints to decide if access to requested data should be allowed. The rule base is constantly updated any time information is released, thus protecting against user inference dynamically. The model is extended to apply to object-oriented programming systems. The notions of data abstraction, data encapsulation and object-oriented programming have become the subject of extensive research. This paper shows how security constraints can be incorporated into the specification for an object. Dynamic protection can therefore be provided for any object by using the filter, inference engine and the rule base, which specifies the security constraints on the object. The specification contains static constraints on the object and on any procedures manipulating the object, while the rule base provides dynamic protection for the object. Finally, an example is presented to illustrate how the model is extended to object-oriented programming systems. The advantages of this extension and future applications are then explored.
Dragoon: an object-oriented notation supporting the reuse and distribution of Ada software
Authors: C. Atkinson, Andrea de Maio, R. Bayan
Venue: Proceedings of the fourth international workshop on Real-time Ada issues (1990)

Among the more radical proposals for changes to the Ada standard in Ada9X are those advocating the introduction of object-oriented features exemplified by languages such as Smalltalk and Eiffel. DRAGOON is a language which supports the fundamental concepts of object-oriented programming in an Ada style, while retaining most of the features of current Ada. In other words it supports Ada-oriented object-oriented programming. It also employs enhanced forms of multiple inheritance to support concurrency and distribution. Therefore, although not designed specifically as a proposal for the Ada9X project, DRAGOON may serve as a basis for the development of Ada in an object-oriented direction. This paper provides a brief overview of the language.
On Optimal Single Jog River Routing (VLSI Layout)
Authors: Tai-Ching Tuan
Venue: IEEE Transactions on Computers (1992)

The wiring problem of providing a planar rectilinear wire connection between two sets of terminals which lie on two horizontal lines in the plane is called the river routing. The problem has been widely studied. It is normally studied in conjunction with design variable(s) optimization problem. The author studies this problem when there is at most one horizontal segment in each wire. Efficient optimal algorithms are given for the following design variables: offset, separation, area, and shortest total wire length. The tight upper bound on the separation is also given.
Optimizing equijoin queries in distributed databases where relations are hash partitioned
Authors: Dennis Shasha, Tsong-Li Wang
Venue: ACM Transactions on Database Systems (TODS) (1991)

Consider the class of distributed database systems consisting of a set of nodes connected by a high bandwidth network. Each node consists of a processor, a random access memory, and a slower but much larger memory such as a disk. There is no shared memory among the nodes. The data are horizontally partitioned often using a hash function. Such a description characterizes many parallel or distributed database systems that have recently been proposed, both commercial and academic. We study the optimization problem that arises when the query processor must repartition the relations and intermediate results participating in a multijoin query. Using estimates of the sizes of intermediate relations, we show (1) optimum solutions for closed chain queries; (2) the NP-completeness of the optimization problem for star, tree, and general graph queries; and (3) effective heuristics for these hard cases. Our general approach and many of our results extend to other attribute partitioning schemes, for example, sort-partitioning on attributes, and to partitioned object databases.
Motion and Structure from Line Correspondences; Closed-Form Solution, Uniqueness, and Optimization
Authors: Juyang Weng, Thomas S. Huang, Narendra Ahuja
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

This work discusses estimating motion and structure parameters from line correspondences of a rigid scene. The authors present a closed-form solution to motion and structure parameters from line correspondences through three monocular perspective views. The algorithm makes use of redundancy in the data to improve the accuracy of the solutions. The uniqueness of the solution is established, and necessary and sufficient conditions for degenerate spatial line configurations are given. Optimization has been employed to further improve the accuracy of the estimates in the presence of noise. Simulations have shown that the errors of the optimized estimates are close to the theoretical lower error bound.
CDAM&mdash;compound document access and management: an object-oriented approach
Authors: Wolfgang Herzner, Erwin Hocevar
Venue: ACM SIGOIS Bulletin (1991)

This paper describes an object-oriented database approach for a direct access and memory management system which covers the needs of storing compound resp. multimedia documents in a multi-user and distributed environment. Document components may be distributed over several physical locations, documents may share components, and multi-user access is supported. In addition, the model allows to represent much of the document semantics, giving the opportunity to define and access components favourable through their properties. Rapid access and manipulation (using for example, associative methods) as well as encapsulation of data to minimize side effects are also considered.
A transformational approach to generating application-specific environments
Authors: David Garlan, Linxi Cai, Robert L. Nord
Venue: ACM SIGSOFT Software Engineering Notes (1992)

Current software development environments tend to lie at opposite ends of a spectrum: at one extreme are specialized application generators; at the other are general-purpose programming environments. The former provide strong support for system development and reuse, but are costly to build and available only for limited domains. The latter provide weak support, but are generally available and universally applicable. We describe a technique for automating the production of application-specific environments that lie between these two extremes. The key idea is that these environments can be derived from general-purpose programming environments by a process of structured transformation. We describe a tool for performing these transformations. It provides a set of formal operators for specializing a description of a general-purpose environment; as operators are applied, the system semi-automatically builds a set of transformation rules used to translate application-specific programs into those of the original general-purpose environment. The output of the tool is an application-specific environment together with a program transformer that provides execution semantics for programs written in that environment.
The Combinatorics of Heuristic Search Termination for Object Recognition in Cluttered Environments
Authors: W. Eric L. Grimson
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

Many current recognition systems terminate a search once an interpretation that is good enough is found. The author formally examines the combinatorics of this approach, showing that choosing correct termination procedures can dramatically reduce the search. In particular, the author provides conditions on the object model and the scene clutter such that the expected search is at most quartic. The analytic results are shown to be in agreement with empirical data for cluttered object recognition. These results imply that it is critical to use techniques that select subsets of the data likely to have come from a single object before establishing a correspondence between data and model features.
Evaluating Design Choices for Shared Bus Multiprocessors in a Throughput-Oriented Environment
Authors: Men-Chow Chiang, Gurindar S. Sohi
Venue: IEEE Transactions on Computers (1992)

The authors consider the evaluation of design choices in multiprocessors with a single, shared bus interconnect operating in an environment in which each task is being executed on a single processor and the performance of the multiprocessor is measured by its overall throughput. To evaluate design choices, they develop mean value analysis analytical models and validate the models by comparing their results against the results of a trace-driven simulation analysis for 5376 multiprocessor configurations. The trace-driven simulation uses actual programs and simulates their execution in a throughput-oriented environment. It is found that: (1) cache block sizes that yield the best performance in a multiprocessor differ from the block sizes that yield the best uniprocessor performance metrics, (2) a larger cache set associativity might be warranted in a multiprocessor even though it might not be warranted in a uniprocessor, (3) a split transaction, pipelined bus yields much higher multiprocessor throughput than a circuit switched bus, especially for larger main memory latencies, and (4) increasing the bus width appears to be an effective way of improving multiprocessor throughput.
Optimal parallel algorithms for triangulated simple polygons
Authors: John Hershberger
Venue: Proceedings of the eighth annual symposium on Computational geometry (1992)

We provide optimal parallel solutions to several shortest path and visibility problems set in triangulated simple polygons. Let P be a triangulated simple polygon with n vertices, preprocessed to support shortest path queries. We can find the shortest path tree from any point inside P in O(log n) time using O(n/log n) processors. In the same bounds, we can preprocess P for shooting queries (a query can be answered in O(log n0 time by a uniprocessor). Given a set S of m points inside P, we can find an implicit representation of the relative convex hull of S in O(log(nm)) time with O(k/log(nm)) processors. All of these algorithms are deterministic and use the CREW PRAM model.
A parallel Monte Carlo search algorithm for the conformational analysis of proteins
Authors: Daniel R. Ripoll, Stephen J. Thomas
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

In recent years several approaches have been proposed to overcome the multiple minima problem associated with non-linear optimization techniques used in the analysis of molecular conformations. One such technique based on a parallel Monte Carlo search algorithm is analysed. Experiments on the Intel iPSC/2 confirm that the attainable parallelism is limited by the underlying acceptance rate in the Monte Carlo search. It is proposed that optimal performance can be achieved in combination with vector processing. Tests on both the IBM 3090 and Intel iPSC/2-VX indicate that vector performance is related to molecule size and vector pipeline latency.
Temporal relations in geographic information systems: a workshop at the University of Maine
Authors: Renato Barrera, Andrew Frank, Khaled Al-Taha
Venue: ACM SIGMOD Record (1991)

A workshop on temporal relations in Geographic Information Systems (GIS) was held on October 12-13, 1990, at the University of Maine. The meeting, sponsored by the National Center for Geographic Information and Analysis (NCGIA), gathered specialists on Geography, GIS, and Computer Science to discuss users' requirements of temporal GIS and to identify the corresponding research issues.
Introducing CASE tools into the software development group
Authors: J. Györkös, I. Rozman, T. Welzer
Venue: ACM SIGSOFT Software Engineering Notes (1990)

Conventional groups for software development try to increase its efficiency with a more advanced approach to all phases of software life cycle. The need for more formal specifications demands the introduction of computer aided tools which base on the empirically confirmed methodologies. The most important task of CASE tools is to unite the methodologies for covering various life cycle phases under one shell. In the paper the problems, appearing in the contact of the tool with the subjects of the developers team are described.