ppxscal/embedding_network huggingface dataset:
Stable adaptive control of robot manipulators using &ldquo;neural&rdquo; networks
Authors: Robert M. Sanner, Jean-Jacques E. Slotine
Venue: Neural Computation (1995)

The rapid development and formalization of adaptive signal processing algorithms loosely inspired by biological models can be potentially harnessed for use in flexible new learning control algorithms for nonlinear dynamic systems. However, if such controller designs are to be viable in practice, their stability must be guaranteed and their performance quantified. In this paper, the stable adaptive tracking control designs employing "neural" networks, initially presented in Sanner and Slotine (1992), are extended to classes of multivariable mechanical systems, including robot manipulators, and bounds are developed for the magnitude of the asymptotic tracking errors and the rate of convergence to these bounds. This new algorithm permits simultaneous learning and control, without recourse to an initial identification stage, and is distinguished from previous stable adaptive robotic controllers, e.g. (Slotine and Li 1987), by the relative lack of structure assumed in the design of the control law. The required control is simply considered to contain unknown functions of the measured state variables, and adaptive "neural" networks are used to stably determine, in real time, the entire required functional dependence. While computationally more complex than explicitly model-based techniques, the methods developed in this paper may be effectively applied to the control of many physical systems for which the state dependence of the dynamics is reasonably well understood, but the exact functional form of this dependence, or part thereof, is not, such as underwater robotic vehicles and high performance aircraft.
A maximum entropy approach to natural language processing
Authors: Adam L. Berger, Vincent J. Della Pietra, Stephen A. Della Pietra
Venue: Computational Linguistics (1996)

The concept of maximum entropy can be traced back along multiple threads to Biblical times. Only recently, however, have computers become powerful enough to permit the widescale application of this concept to real world problems in statistical estimation and pattern recognition. In this paper, we describe a method for statistical modeling based on maximum entropy. We present a maximum-likelihood approach for automatically constructing maximum entropy models and describe how to implement this approach efficiently, using as examples several problems in natural language processing.
Applications of machine learning and rule induction
Authors: Pat Langley, Herbert A. Simon
Venue: Communications of the ACM (1995)

Machine learning is the study of computational methods for improving performance by mechanizing the acquisition of knowledge from experience. Expert performance requires much domain-specific knowledge, and knowledge engineering has produced hundreds of AI expert systems that are now used regularly in industry. Machine learning aims to provide increasing levels of automation in the knowledge engineering process, replacing much time-consuming human activity with automatic techniques that improve accuracy or efficiency by discovering and exploiting regularities in training data. The ultimate test of machine learning is its ability to produce systems that are used regularly in industry, education, and elsewhere.
A fast algorithm for minimizing FPGA combinational and sequential modules
Authors: Dimitrios Kagaris, Spyros Tragoudas
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (1996)

We present a quadratic-time algorithm for minimizing the number of modules in an FPGA with combinational and sequential modules (like the C-modules and S-modules of the ACT2 and ACT3 architectures). The constraint is that a combinational module can be combined with one flip-flop in a single sequential module, only if the combinational module drives no other combinational modules. Our algorithm uses a minimum-cost flow formulation to solve the problem with a significant time improvement over a previous approach that used a general linear program.
Turkey: a report on computer graphics education
Authors: Bülent Özgüç
Venue: ACM SIGGRAPH Computer Graphics (1996)

In a formal or an informal manner, computer graphics has been a field of research and education since the early 1970s in Turkey. The earlier examples of academic research work came from Istanbul Technical University and Middle East Technical University in Ankara. Istanbul Technical University research efforts were basically on computer-aided design, whereas at the Middle East Technical University, more theoretical computer graphics work has been carried on.Two examples can be given of early theoretical graphics work: A hidden line elimination algorithm by Ibrahim Canbulat, and an automated drafting algorithm by the author [2, 3]. To the best of my knowledge, the earliest official computer graphics course was offered at the Middle East Technical University in 1979. With the establishment of Bilkent University in Ankara, the first private university in Turkey, computer graphics became an official track of study, not only in computer engineering, but in fine arts as well.In this paper, we examine the current state of computer graphics education in Turkey under two main headings. First, the educational activities within the departments of computer science will be examined. Then, the educational activities within the schools of art and design will be looked at. In order to find out the educational activities at various universities, we have written to 52 departments at 40 universities. The information given in this report is based on the responses from these departments. Many departments at various schools offer technical drawing courses by the use of drafting software. These have not been classified as computer graphics courses.
Parallelizing Iterative Loops with Conditional Branching
Authors: Gyungho Lee
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

This paper considers automatic restructuring of loops with conditional branching for parallel processing, especially a class of loops termed ¿conditional cyclic loops.¿ A conditional cyclic loop possesses a dependence cycle caused by conditional branching across loop iterations, which makes it difficult to parallelize. In general, parallel execution of a conditional cyclic loop provides little benefit due to the need of solving a full-order nonlinear Boolean recurrence relation. However, the Boolean recurrence in practice is often of simpler forms. With the simpler forms, the number of possible predicate values of conditional branching is reduced drastically compared to a general conditional cyclic loop. These simple forms of conditional cyclic loops found in practice can be parallelized for $O(p/\log p)$ speedup with $p$ processors.Index Terms¿Automatic program restructuring, conditional cyclic loop, data dependence, linear mixed recurrence loop, parallel algorithm, postfix-IF loop.
A functional layer for description logics: knowledge representation meets object-oriented programming
Authors: Ralf Möller
Venue: ACM SIGPLAN Notices (1996)

The paper motivates the facilities provided by Description Logics in an object-oriented programming scenario. It presents a unification approach of Description Logics and object-oriented programming that allows both views to be conveniently used for different subproblems in a modern software-engineering environment. The main thesis of this paper is that in order to use Description Logics in practical applications, a seamless integration with object-oriented system development methodologies must be realized.
Embra: fast and flexible machine simulation
Authors: Emmett Witchel, Mendel Rosenblum
Venue: Proceedings of the 1996 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1996)

This paper describes Embra, a simulator for the processors, caches, and memory systems of uniprocessors and cache-coherent multiprocessors. When running as part of the SimOS simulation environment, Embra models the processors of a MIPS R3000/R4000 machine faithfully enough to run a commercial operating system and arbitrary user applications. To achieve high simulation speed, Embra uses dynamic binary translation to generate code sequences which simulate the workload. It is the first machine simulator to use this technique. Embra can simulate real workloads such as multiprocess compiles and the SPEC92 benchmarks running on Silicon Graphic's IRIX 5.3 at speeds only 3 to 9 times slower than native execution of the workload, making Embra the fastest reported complete machine simulator. Dynamic binary translation also gives Embra the flexibility to dynamically control both the simulation statistics reported and the simulation model accuracy with low performance overheads. For example, Embra can customize its generated code to include a processor cache model which allows it to compute the cache misses and memory stall time of a workload. Customized code generation allows Embra to simulate a machine with caches at slowdowns of only a factor of 7 to 20. Most of the statistics generated at this speed match those produced by a slower reference simulator to within 1%. This paper describes the techniques used by Embra to achieve high performance, focusing on the requirements unique to machine simulation, including modeling the processor, memory management unit, and caches. In order to study Embra's memory system performance we use the SimOS simulation system to examine Embra itself. We present a detailed breakdown of Embra's memory system performance for two cache hierarchies to understand Embra's current performance and to show that Embra's implementation techniques benefit significantly from the larger cache hierarchies that are becoming available. Embra has been used for operating system development and testing as well as for studies of computer architecture. In this capacity it has simulated large, commercial workloads including IRIX running a relational database system and a CAD system for billions of simulated machine cycles.
An aspect of query optimization in multidatabase systems
Authors: Chiang Lee, Chia-Jung Chen, Hongjun Lu
Venue: ACM SIGMOD Record (1995)

It is becoming increasingly important to manage databases as a repository resource and to allow application programs to access this resource in a heterogeneous distributed environment. Data requested by a query are sometimes available in multiple sites such that the query becomes executable in different ways. Under this circumstance, choosing the best execution plan becomes an important task for optimizing the query execution. Until today, however, query optimization in multidatabase systems has not been discussed much in the literature. In this work, we utilize the knowledge of scope relationship of relations in multidatabases to identify the sites that will return the same results. Then, we propose a novel way of optimizing queries which takes advantage of the conflicts of schemas in searching for the execution plan with the least execution cost. We achieve the goal by first classifying various schema conflicts into different types. The costs of executing the same relational operation on relations of conflicting schemas are evaluated and a weight is assigned to each of the cases to reflect the complexity of executing the operation. As this method only involves simple iterative computations of the weights and the saving of a query execution time can be dramatic, the method developed here can be regarded as an effective way of optimizing query processing in a multidatabase environment.
The role of lazy evaluation in amortized data structures
Authors: Chris Okasaki
Venue: Proceedings of the first ACM SIGPLAN international conference on Functional programming (1996)

Traditional techniques for designing and analyzing amortized data structures in an imperative setting are of limited use in a functional setting because they apply only to single-threaded data structures, yet functional data structures can be non-single-threaded. In earlier work, we showed how lazy evaluation supports functional amortized data structures and described a technique (the banker's method) for analyzing such data structures. In this paper, we present a new analysis technique (the physicist's method) and show how one can sometimes derive a worst-case data structure from an amortized data structure by appropriately scheduling the premature execution of delayed components. We use these techniques to develop new implementations of FIFO queues and binomial queues.
An empirical model for accurate estimation of routing delay in FPGAs
Authors: Tanay Karnik, Sung-Mo Kang
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

We present an empirical routing delay model for estimating interconnection delays in FPGAs. We assume that the routing delay is a function of interPLC distances, circuit size, fanout of the net and routing congestion in the channel. We performed extensive simulations of various circuits to generate a sufficiently large dataset. Our method estimates delays by reading the average value tables and interpolating the values, if necessary. We present a rigorous statistical justification of this delay model. Our results show that our method predicts the delays within 20% of actual and it far outperforms all other existing techniques.
SM-prof: a tool to visualise and find cache coherence performance bottlenecks in multiprocessor programs
Authors: Mats Brorsson
Venue: Proceedings of the 1995 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems (1995)

Cache misses due to coherence actions are often the major source for performance degradation in cache coherent multiprocessors. It is often difficult for the programmer to take cache coherence into account when writing the program since the resulting access pattern is not apparent until the program is executed.SM-prof is a performance analysis tool that addresses this problem by visualising the shared data access pattern in a diagram with links to the source code lines causing performance degrading access patterns. The execution of a program is divided into time slots and each data block is classified based on the accesses made to the block during a time slot. This enables the programmer to follow the execution over time and it is possible to track the exact position responsible for accesses causing many cache misses related to coherence actions.Matrix multiplication and the MP3D application from SPLASH are used to illustrate the use of SM-prof. For MP3D, SM-prof revealed performance limitations that resulted in a performance improvement of over 75%.The current implementation is based on program-driven simulation in order to achieve non-intrusive profiling. If a small perturbation of the program execution is acceptable, it is also possible to use software tracing techniques given that a data address can be related to the originating instruction.
When is the Assignment Bound Tight for the Asymmetric Traveling-Salesman Problem?
Authors: Alan Frieze, Richard M. Karp, Bruce Reed
Venue: SIAM Journal on Computing (1995)

We consider the probabilistic relationship between the value of a random asymmetric traveling salesman problem $ATSP(M)$ and the value of its assignment relaxation $AP(M)$. We assume here that the costs are given by an $n\times n$ matrix $M$ whose entries are independently and identically distributed. We focus on the relationship between $Pr(ATSP(M)=AP(M))$ and the probability $p_n$ that any particular entry is zero. If $np_n\rightarrow \infty$ with $n$ then we prove that $ATSP(M)=AP(M)$ with probability 1-o(1). This is shown to be best possible in the sense that if $np(n)\rightarrow c$, $c>0$ and constant, then $Pr(ATSP(M)=AP(M))
Simulation and statistical education
Authors: Jorge Luis Romeu
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Discrete event simulation has benefited from statistical analysis but the reverse is not true. Recent advances in computer technology and software development have made it possible to have PC's running specialized simulation languages readily available. The paper discusses how discrete event simulation, developed via specialized simulation languages (e.g., GPSS), can become a useful class resource to teach and motivate statistics students. In addition, simulation helps to present, more effectively, interdisciplinary case studies, to increase group learning and to relieve students and instructors from statistical drudgery. Examples of such GPSS simulation are developed.
Quadrature prefiltering for high quality antialiasing
Authors: Brian Guenter, Jack Tumblin
Venue: ACM Transactions on Graphics (TOG) (1996)

This article introduces quadrature prefiltering, an accurate, efficient, and fairly simple algorithm for prefiltering polygons for scanline rendering. It renders very high quality images at reasonable cost, strongly suppressing aliasing artifacts. For equivalent RMS error, quadrature prefiltering is significantly faster than either uniform or jittered supersampling. Quadrature prefiltering is simple to implement and space-efficient; it needs only a small two-dimensional lookup table, even when computing nonradially symmetric filter kernels. Previous algorithms have required either three-dimensional tables or a restriction to radially symmetric filter kernels. Though only slightly more complicated to implement than the widely used box prefiltering method, quadrature prefiltering can generate images with much less visible aliasing artifacts.
Modified Projection-Type Methods for Monotone Variational Inequalities
Authors: Michael V. Solodov, Paul Tseng
Venue: SIAM Journal on Control and Optimization (1996)

We propose new methods for solving the variational inequality problem where the underlying function $F$ is monotone. These methods may be viewed as projection-type methods in which the projection direction is modified by a strongly monotone mapping of the form $I - \alpha F$ or, if $F$ is affine with underlying matrix $M$, of the form $I+ \alpha M^T$, with $\alpha \in (0,\infty)$. We show that these methods are globally convergent, and if in addition a certain error bound based on the natural residual holds locally, the convergence is linear. Computational experience with the new methods is also reported.
Linear decomposition algorithm for VLSI design applications
Authors: Jianmin Li, John Lillis, Chung-Kuan Cheng
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

We propose a unified solution to both linear placement and partitioning. Our approach combines the well-known eigenvector optimization method with the recursive max-flow min-cut method. A linearized eigenvector method is proposed to improve the linear placement. A hypergraph maxflow algorithm is then adopted to efficiently find the max-flow min-cut. In our unified approach, the max-flow min-cut provides an optimal ordered partition subject to the given seeds and the eigenvector placement provides heuristic information for seed selection. Experimental results on MCNC benchmarks show that our approach is superior to other methods for both linear placement and partitioning problems. On average, our approach yields an improvement of 45.1% over eigenvector approach in terms of total wire length, and yields an improvement of 26.9% over PARABOLI in terms of cut size.
Prevention of Congestion in Packet-Switched Multistage Interconnection Networks
Authors: Jyh-Charn Liu, Kang G. Shin, Charles C. Chang
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

This paper proposes a simple, yet effective scheme to prevent congestion in a packet-switched multistage interconnection network (MIN) caused by hot spots. In this scheme, switches in the second and third stages of the MIN monitor their buffer occupancy to detect any notable nonuniform access behavior. When a switch detects congestion, packets generated by processors will be blocked from entering the congested switch until the congestion is cleared. Our scheme is compared with two well known schemes [1], [2], and shown to exhibit significantly better performance than these two.Index Terms¿Congestion tree, packet-switching, multistage interconnection networks (MIN), hot spots, buffer occupancy.
Secure communication using remote procedure calls
Authors: Andrew D. Birrell
Venue: ACM Transactions on Computer Systems (TOCS) (1985)

Research on encryption-based secure communication protocols has reached a stage where it is feasible to construct end-to-end secure protocols. The design of such a protocol, built as part of a remote procedure call package, is described. The security abstraction presented to users of the package, the authentication mechanisms, and the protocol for encrypting and verifying remote calls are also described.
Measuring IS: how does your organization rate?
Authors: H. A. Smith, J. D. McKeen
Venue: ACM SIGMIS Database (1996)

In today's difficult economy, companies are reorganizing and streamlining wherever possible in order to save money and attract customers. This new corporate emphasis on better organizational performance, i.e., both productivity and quality goods and services, challenges all parts of an organization, including IS, to make improvements in what they do and how they operate. This is easier said than done and many organizations are having difficulties knowing where to start, what to do, and what their goals should be. Organizational learning change are the hallmarks of business in the nineties and the starting point for this effort is the collection of accurate and adequate information and its appropriate analysis.It is not surprising therefore that comparison, measurement, and evaluation have become something of a preoccupation in many businesses in recent years. The U.S. National Quality Institute, (which establishes the detailed criteria for the Malcolm Baldridge Awards), suggests there are three components of effective information and analysis which act as the "brain center" driving the corporate improvement effort, regardless of a company's organization or structure (Baldridge Criteria, 1993):1. Scope and management of quality and performance information.2. Collection, analysis, and use of company level data, including customer data and operations data, and linking performance data to overall financial performance.3. Competitive comparisons and benchmarking.These criteria can also be used by individual corporate subunits to determine how well they contribute to overall quality and performance.One organizational subunit receiving a considerable amount of executive attention in this regard is the information systems (IS) function. Many companies are looking to information technology to help them support corporate restructuring, but to do it with increasingly fewer resources. Unfortunately, IS has also been an area of the company that has been extremely difficult to measure and evaluate. IS also continues to have a credibility problem in some organizations where executives believe that IS has contributed little or nothing to the corporate bottom line (Roach, 1989). As well, there are still many users who tend to feel that IS service is lacking or could be bought cheaper elsewhere. With IS budgets coming under closer and closer scrutiny, IS itself is placing new emphasis on measurement to demonstrate its contribution to overall corporate performance, both through quality services and systems and through its ability to do so cost-effectively.This paper looks at the three components of information and its analysis, as outlined above, from the perspective of the IS subunit. It summarizes what IS departments are doing to assess and analyze their organizations and makes suggestions about how the measurement and evaluation of IS both internally and externally could be improved.