ppxscal/embedding_network huggingface dataset:
Practical considerations to speed up Lagrangian stochastic particle models
Authors: Stephan Schwere, Andreas Stohl, Mathias W. Rotach
Venue: Computers Geosciences (2002)

The most serious drawback of Lagrangian stochastic particle models is their excessive demand of computing time. Even with today's powerful computers this makes them unattractive for many practical applications, such as for the assessment of air pollution in a long-term (e.g., yearly) scenario. This contribution therefore focuses on two issues: firstly, on which specific tasks do these models 'waste' computing time? Secondly, methods are presented in order specifically to reduce the computing time of these tasks. It is shown that for 'simple' models (e.g. those suited for Gaussian homogeneous turbulence) a speed-up factor of 10-100 can be reached when following these reduction strategies. The overall speed-up factor is about two for a more sophisticated model, which takes into account skewed and inhomogeneous turbulence. The results from the 'speeded-up simulations' are compared with the original model's results and it is shown that the speed-up procedures do not significantly alter the concentration patterns.
Validating Expert Systems
Authors: Timothy J. O'Leary, Michael Goul, Kathleen E. Moffitt, A. Essam Radwan
Venue: IEEE Expert: Intelligent Systems and Their Applications (1990)

D.E. O'Leary (1987) noted the inappropriate nature of traditional software validation techniques for expert system validation and proposed a research methods approach. R.M. O'Keefe et al. (1987) established validation as an important concern in expert system research and development and presented general descriptive methodologies for qualitative and quantitative methods of formal validation. A specific formal paradigm for prototype validation that is consistent with O'Leary's as well as O'Keefe's general guidelines for expert system development is presented. The paradigm explicitly incorporates validation into the prototype development life cycle under constrained resources, primarily time and money. The validation approach is demonstrated and evaluated relative to an expert system prototype named Signal Control at Isolated Intersections. The paradigm's strengths and weaknesses as well as its potential use with other types of expert system development projects are examined.
Superscalar Instruction Issue
Authors: Dezsõ Sima
Venue: IEEE Micro (1997)

While providing a considerable potential for parallel execution, the performance of a superscalar microarchitecture depends heavily on the particular instruction issue scheme chosen. In this paper, we focus on the instruction issue task of superscalar processors. We first identify the design space of superscalar instruction issue by indicating important design aspects and associated design choices. Through the use of DS-trees we represent the design space in a concise graphical way. We also explore it by showing the design choices made in recent superscalar processors, highlighting the most frequently used issue schemes and prevailing trends.
Hardware Compilation: Translating Programs into Circuits
Authors: Niklaus Wirth
Venue: Computer (1998)

Automatically translating a program specified in a programming language into a digital circuit is an idea of long-standing interest. Thus far, the concept has appeared to be an uneconomical method of largely academic, but hardly practical, interest. It has therefore not been pursued with vigor and consequently has remained an idealist's dream. With the increasing use of hardware description languages, however, it has become evident that hardware and software design share several traits. Hardware description languages let circuit specifications assume textual forms like programs, replacing traditional circuit diagrams with text. Increased interest in hardware compilation is largely due to the advent of large-scale programmable devices. These devices can be configured on the fly, and hence be used to directly represent circuits generated through a hardware compiler. The author argues that it is now conceivable that parts of a program could be compiled into instruction sequences for a conventional processor and other parts could be compiled into circuits to be loaded onto programmable gate arrays. He advocates the development of a single language that could compile parts of a program into instruction sequences for a conventional processor and other parts into circuits for programmable gate arrays.
Design of High Speed AWGN Communication Channel Emulator
Authors: Emmanuel Boutillon, Jean-Luc Danger, Adel Ghazel
Venue: Analog Integrated Circuits and Signal Processing (2003)

This paper presents a method for designing a high accuracy white gaussian noise generator suitable for communication channel emulation. The proposed solution is based on the combined use of the Box-Muller method and the central limit theorem. The resulting architecture provides a high accuracy AWGN with a low complexity architecture for a digital implementation in FPGA. The performance is studied by means of MATLAB simulations and various complexity figures are given.
A Tale of Two Futures
Authors: Ed Yourdon
Venue: IEEE Software (1998)

With apologies to Charles Dickens, the likely future of the software industry is this: it will be either the best of times or the worst of times-or both. For those who have enjoyed a career consisting of good times year after year, the natural assumption is that next year will bring more challenging projects, more exciting technologies, more income, and even the possibility of lucrative stock options. But those who have nightmare glimpses of software's dark side worry that the good times are coming to an end and that the impending Year 2000 crisis may plunge us all into several years of decidedly unpleasant times. These good- and bad-times scenarios may well coexist. That a hotshot Java programmer can earn $250,000 per year won't prevent other software professionals from being unemployed; we've already seen this during the past decade, when highly paid mainframe programmers found themselves replaced by less expensive PC programmers. Software is now a huge global industry with some three million professionals who call themselves programmers, software engineers, or some similar title; several million more people hold jobs that depend directly on the fortunes of internal IS/IT departments or software producers such as Microsoft and IBM. Although it's convenient to think of the term "software developer" as a generic job description, like carpenter or plumber, the field actually encompasses dozens of different specializations, many so divergent their practitioners can barely communicate with one another. Given software development's breadth and diversity, I think it highly unlikely the entire industry will enjoy boom times in the coming years. Likewise, I doubt that the entire profession will collapse. But some generic issues and problems will likely affect the spectrum of software developers. How we respond to them will determine whether we enjoy success or failure.
A New Implementation of Automath
Authors: Freek Wiedijk
Venue: Journal of Automated Reasoning (2003)

This paper presents aut, a modern Automath checker. It is a straightforward re-implementation of the Zandleven Automath checker from the seventies. It was implemented about five years ago, in the programming language C. It accepts both the AUT-68 and AUT-QE dialects of Automath. This program was written to restore a damaged version of Jutting's translation of Landau's Grundlagen. Some notable features: &bull; It is fast. On a 1 GHz machine it will check the full Jutting formalization (736 K of nonwhitespace Automath source) in 0.6 seconds.&bull; Its implementation of &lambda;-terms does not use named variables or de Bruijn indices (the two common approaches) but instead uses a graph representation. In this representation variables are represented by pointers to a binder.&bull; The program can compile an Automath text into one big &lsquo;Automath single line&rsquo;-style &lambda;-term. It outputs such a term using de Bruijn indices. (These &lambda;-terms cannot be checked by modern systems like Coq or Agda, because the &lambda;-typed &lambda;-calculi of de Bruijn are different from the &Pi;-typed &lambda;-calculi of modern type theory.) The source of aut is freely available on the Web at the address < http://www.cs.kun.nl/~freek/aut/ >.
Indexing Animated Objects Using Spatiotemporal Access Methods
Authors: George Kollios, Vassilis J. Tsotras, Dimitrios Gunopulos, Alex Delis, Marios Hadjieleftheriou
Venue: IEEE Transactions on Knowledge and Data Engineering (2001)

We present a new approach for indexing animated objects and efficiently answering queries about their position in time and space. In particular, we consider an animated movie as a spatiotemporal evolution. A movie is viewed as an ordered sequence of frames, where each frame is a 2D space occupied by the objects that appear in that frame. The queries of interest are range queries of the form, ¿find the objects that appear in area $S$ between frames $f_i$ and $f_j$¿ as well as nearest neighbor queries such as, ¿find the $q$ nearest objects to a given position $A$ between frames $f_i$ and $f_j$.¿ The straightforward approach to index such objects considers the frame sequence as another dimension and uses a 3D access method (such as, an R-Tree or its variants). This, however, assigns long ¿lifetime¿ intervals to objects that appear through many consecutive frames. Long intervals are difficult to cluster efficiently in a 3D index. Instead, we propose to reduce the problem to a partial-persistence problem. Namely, we use a 2D access method that is made partially persistent. We show that this approach leads to faster query performance while still using storage proportional to the total number of changes in the frame evolution. What differentiates this problem from traditional temporal indexing approaches is that objects are allowed to move and/or change their extent continuously between frames. We present novel methods to approximate such object evolutions. We formulate an optimization problem for which we provide an optimal solution for the case where objects move linearly. Finally, we present an extensive experimental study of the proposed methods. While we concentrate on animated movies, our approach is general and can be applied to other spatiotemporal applications as well.
A Note on Complexity of OBDD Composition and Efficiency of Partitioned-OBDDs over OBDDs
Authors: Jawahar Jain, Ingo Wegener, Masahiro Fujita
Venue: IEEE Transactions on Computers (2001)

We discuss an open problem with constructing an OBDD using composition and prove that the worst case complexity of the construction is truly cubic. Using this insight, we show compactness of partitioned-OBDDs over monolithic OBDDs.
A Systematic (16,8) Code for Correcting Double Errors and Detecting Triple-Adjacent Errors
Authors: T. A. Gulliver, V. K. Bhargava
Venue: IEEE Transactions on Computers (1993)

A double error correcting systematic (16,8) quasi-cycle (QC) code that can detect all triple-adjacent errors within each 8-b byte is presented. This code is useful in computer memory applications where adjacent errors are more likely than random errors. As an alternative, a systematic (24,16) QC code is given which corrects single errors, and detects all double errors in addition to all triple-adjacent and quadruple-adjacent errors. A third code, a systematic (32,16) QC code, is presented which corrects all triple errors and detects all quadruple errors. Decoding can be achieved either by syndrome generation and table lookup or by majority logic.
The Design of Efficient Algorithms for Two-Dimensional Pattern Matching
Authors: Jang-Jongm Fanm, Keh-Yih Su
Venue: IEEE Transactions on Knowledge and Data Engineering (1995)

The two-dimensional pattern matching problem is to find the occurrences of a given two-dimensional pattern array in a two-dimensional text array. This paper presents two efficient algorithms, which combine Fan-Su and Aho-Corasick string search algorithms, to solve this problem. The proposed algorithms need not inspect each character of the text array during the pattern matching in most cases. Additionally, unlike the algorithms proposed by Zhu and Takaoka which are based on the hashing method, these new algorithms require no preprocessing of the text array. The comparison of the performance among various algorithms are depicted in this paper. The result shows that the proposed algorithms are about three to six times faster than the best algorithm proposed previously when the size of the pattern array is less than 1/100 of the size of the text array, which occurs frequently in many applications.
Knapsack on VLSI: from Algorithm to Optimal Circuit
Authors: Rumen Andonov, Sanjay Rajopadhye
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

We present a parallel solution to the unbounded knapsack problem on a linear systolic array. It achieves optimal speedup for this well-known, NP-hard problem on a model of computation that is weaker than the PRAM. Our array is correct by construction, as it is formally derived by transforming a recurrence equation specifying the algorithm.This recurrence has dynamic dependencies, a property that puts it beyond the scope of previous methods for automatic systolic synthesis. Our derivation thus serves as a case study. We generalize the technique and propose a systematic method for deriving systolic arrays by nonlinear transformations of recurrences. We give sufficient conditions that the transformations must satisfy, thus extending systolic synthesis methods.We address a number of pragmatic considerations: implementing the array on only a fixed number of PEs, simplifying the control to just two counters and a few latches, and loading the coefficients so that successive problems can be pipelined without any loss of throughput.Using a register level model of VLSI, we formulate a nonlinear optimization problem to minimize the expected running time of the array. The analytical solution of this problem allows us to choose the memory size of each PE in an optimal manner.
Rate Monotonic Analysis for Real-Time Systems
Venue: Computer (1993)

Rate monotonic analysis (RMA), a mathematical approach that helps ensure that a real-time system meets its performance requirements, is discussed. It does so through a collection of quantitative methods and algorithms that let engineers understand, analyze, and predict the timing behavior of their designs. An application of RMA to an air traffic control system is described.
Managing Data through Naming Standards
Venue: IEEE Software (1990)

No abstract available The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Case study: a look of performance expression
Authors: Rumi Hiraga
Venue: Proceedings of the conference on Visualization '02 (2002)

For most of the time, we enjoy and appreciate music performances as they are. Once we try to understand the performance not in subjective terms but in an objective way and share it with other people, visualizing the performance parameters is indispensable. In this paper, a figure for visualizing performance expressions is described. This figure helps people understand the cause and position of the performance expression as it has expressive cues, which coincide with the cognitive meaning of musical performance, and not by using only MIDI parameter values. The differences we hear between performances are clarified by visualized figures.
On the Efficiency of a Global Non-differentiable Optimization Algorithm Based on the Method of Optimal Set Partitioning
Authors: Elena Kiseleva, Tatyana Stepanchuk
Venue: Journal of Global Optimization (2003)

The examined algorithm for global optimization of the multiextremal non-differentiable function is based on the following idea: the problem of determination of the global minimum point of the function f(x) on the set &Omega;(f(x) has a finite number of local minima in this domain) is reduced to the problem of finding all local minima and their attraction spheres with a consequent choice of the global minimum point among them. This reduction is made by application of the optimal set partitioning method. The proposed algorithm is evaluated on a set of well-known one-dimensional, two-dimensional and three-dimensional test functions. Recommendations for choosing the algorithm parameters are given.
An Optimal Channel Access Protocol with Multiple Reception Capacity
Authors: I. Chlamtac, A. Farago
Venue: IEEE Transactions on Computers (1994)

A multiple access packet communication model is analyzed in which the users can receive packets on more than one common channel. For this type of system, a new channel access protocol is presented. The authors prove that under heavy homogeneous load the protocol guarantees the maximum achievable throughput among all possible protocols. The general model can be applied to different systems, according to various realizations of the logical channels. For example, in packet radio networks the channels can be realized by different carrier frequencies (FDMA) or by different codes (CDMA). The simplicity and optimality of the protocol make it attractive for practical applications.
Kernel Nearest-Neighbor Algorithm
Authors: Kai Yu, Liang Ji, Xuegong Zhang
Venue: Neural Processing Letters (2002)

The &lsquo;kernel approach&rsquo; has attracted great attention with the development of support vector machine (SVM) and has been studied in a general way. It offers an alternative solution to increase the computational power of linear learning machines by mapping data into a high dimensional feature space. This &lsquo;approach&rsquo; is extended to the well-known nearest-neighbor algorithm in this paper. It can be realized by substitution of a kernel distance metric for the original one in Hilbert space, and the corresponding algorithm is called kernel nearest-neighbor algorithm. Three data sets, an artificial data set, BUPA liver disorders database and USPS database, were used for testing. Kernel nearest-neighbor algorithm was compared with conventional nearest-neighbor algorithm and SVM Experiments show that kernel nearest-neighbor algorithm is more powerful than conventional nearest-neighbor algorithm, and it can compete with SVM.
A Wireless Network in MosquitoNet
Authors: Stuart Cheshire, Mary Baker
Venue: IEEE Micro (1996)

As the trend towards smaller, lighter and more powerful computers continues, mobility and wireless connectivity become increasingly important.The MosquitoNet project is studying issues in wireless and mobile computing, and this article presents our performance analysis and observations of one of the emerging wireless technologies: the Metricom Microcellular Digital Network (MCDN).Metricom provides one of the best combinations of bandwidth, coverage area and cost for a wireless data network. We find that the throughput of their radio devices is ccomparable to a modern modem, but the latency, or round-trip delay, is much higher. The maximum throughput we measured was 30-40 Kbits/second, but the minimum latency for even the smallest IP packet is at least 60ms.We have experimented with both the datagram and Hayes modem emulation modes of Metricom's wireless radios. We are early users of the datagram mode, and our experiences confirm two sometimes-forgotten principles. First, packet switching allows more efficient sharing of resources than does circuit switching. Second, interfaces that are satisfactory for use by human beings often show their flaws, ambiguities and omissions when used as programming interfaces for software control of devices.
Eigenstate selection in open quantum dot systems: using the Landauer formalism as a spectroscopic probe
Authors: R. Akis, J. P. Bird, D. K. Ferry
Venue: Microelectronic Engineering (2002)

We show that transport in open quantum dots can be mediated by single eigenstates, even when the leads allow several propagating modes. The broadening of these states can be virtually independent of lead width. While sets of completely broadened states contribute to the background conductance, the states that remain resolved tend to yield periodic conductance fluctuations that are observable in experiment.
Economics of Built-in Self-Test
Authors: Louis Y. Ungar, Tony Ambler
Venue: IEEE Design Test (2001)

Using built-in self-test at the right level offers users significant cost savings, but determining which level, if any, is best for BIST can be complex. A detailed economic analysis can unravel heterogeneous costs and benefits so that designers and managers can make the right decision.
Interactive Critiquing forCatalog Navigation in E-Commerce
Authors: Robin Burke
Venue: Artificial Intelligence Review (2002)

E-commerce sites can have large, essentially unbounded, catalogs. With large catalogs comes increasing difficulty for buyers in making use of standard search and browsing facilities. Particularly in the case of casual or occasional buyers and in the case of complex products, the gap between a product's specifications and the buyer's understanding of need can be hard to bridge. An effective e-commerce catalog must map user needs to products that can fulfill them. This paper describes an interactive, incremental, case-based, critiquing approach to solving this problem. The approach is interactive and incremental, so it does not require that the user have a completely specified need at the start. The system is case-based in that it emphasizes products over features or constraints, and uses case-based reasoning techniques for its product retrieval. Finally, the approach is based on the critiquing of presented examples, each critique redirecting the search to home in on appropriate products.
Problems and promises in the study of virtual communities
Authors: Susan C. Kinnevy, Guy Enosh
Venue: Journal of Technology in Human Services (2002)

This paper discusses several methodological approaches to the study of virtual communities, including comparative designs, statistical approaches, and ethnography. In particular, we present results from one study that exemplifies both the problems and promises inherent in researching virtual communities. This study examines the daily interactions of peace activists in a virtual community devoted to nonviolent solutions to world problems. By analyzing narrative messages exchanged over a four-month period categorically in terms of topic, type, scope, and content, the study explores community design issues of gatekeeping and normative standards in a virtual community.
Perceptual activity measures computed from blocks in the transform domain
Authors: Yu-Hwe Lee, Jar-Ferr Yang, Jen-Fa Huang
Venue: Signal Processing (2002)

In this paper, we propose perceptual activity measures, which are computed from weighted transforms of the block, to precisely estimate the sensitivity of blocks. From analysis of principal components of a referred background region, we first suggest a weighted Karhunen-Loeve transformation (KLT) activity measure to characterize the visual variation of the image block. The weighted KLT computed in block-by-block fashions requires large computational complexity. To reduce the computation, we further utilize the first-order Markov's model and discrete cosine transform (DCT) to derive a simplified perceptual activity measure. Simulated results show that the proposed measures achieving precise visual perception can be effectively utilized in many block-based image and video compression systems.
Toward a foundational typed assembly language
Authors: Karl Crary
Venue: ACM SIGPLAN Notices (2003)

We present the design of a typed assembly language called TALT that supports heterogeneous tuples, disjoint sums, and a general account of addressing modes. TALT also implements the von Neumann model in which programs are stored in memory, and supports relative addressing. Type safety for execution and for garbage collection are shown by machine-checkable proofs. TALT is the first formalized typed assembly language to provide any of these features.