ppxscal/embedding_network huggingface dataset:
Estimation of buried sources: a new computational scheme
Authors: V. K. Mathur, S. K. Agrawal
Venue: Proceedings of the sixth conference on Computational structures technology (2002)

Earthquake source determination can be thought as an inverse problem where the system and the responses are known but not the excitation. The strong motion records available during an earthquake can be treated as response of the earth as a structural system to unknown forces acting at unknown locations. Thus, if the part of the earth participating in ground motion is modelled as a known finite elastic medium, one can attempt to model the source location and forces generated during earthquake as an inverse problem in structural dynamics. The paper presents a new computational scheme for finding the excitation source using the free vibration information and the known surface displacements. The methodology proposed makes use of the normal mode approach of structural dynamics along with principle of minimization of mean square error. It has been shown here through numerical experimentation that the input (excitation) can be successfully found i.e. its location and magnitude, using the proposed approach for 2-D finite elastic mediums. It is seen that earthquake source location problem is similar to the 2-D problem illustrated in the paper. Hence, the scheme can be extended for finding location (epicentre) and magnitude of equivalent forces arising during earthquakes.
An O(nlogn)-Algorithm for Solving a Special Class of LP''s
Authors: W W Bein, Peter Brucker
Venue:  (1988)

An $O(nm+nlogn)$ algorithm was developed by Kern [1986] to solve LPs of the form max$\{ cx ~|~ l \leq Ax \leq b, L \leq x \leq U \}$ where $l,b,L,U$ are nonnegative and $A$ is a 0-1 matrix of dimension $m$ x $n$ with the property that the support of each row is contained in the support of every subsequent row. We will show that a more general class of LPs can be solved in $O(nlogn)$-time.
NURBS representation of coated woven fabric behaviour
Authors: B. N. Bridgens, P. D. Gosling
Venue: Proceedings of the sixth conference on Computational structures technology (2002)

Coated woven fabrics are used in a wide range of structural applications to provide lightweight, architecturally striking solutions. NURBS (Non-Uniform Rational B-Splines) are a popular and versatile tool for curve and surface generation in computer aided design and animation applications. This paper investigates the use of NURBS for data fitting in the context of the non-linear biaxial tensile response of coated woven fabrics. The overall research aim is to develop response surfaces for fabric behaviour that are suitable for inclusion in structural design software.
Frequency vs. Probability Formats: Framing the Three Doors Problem
Authors: Eric Aaron, Michael Spivey-Knowlton
Venue:  (1998)

Instead of subscribing to the view that people are unable to perform Bayesian probabilistic inference, recent research suggests that the algorithms people naturally use to perform Bayesian inference are better adapted for information presented in a natural frequency format than in the common probability format. We tested this hypothesis on the notoriously difficult three doors problem, inducing subjects to consider the likelihoods involved in terms of natural frequencies or in terms of probabilities. We then examined their ability to perform the mathematics underlying the problem, a stronger indication of Bayesian inferential performance than merely whether they gave the correct answer to the problem. With a robustness that may surprise people unfamiliar with the effects of information formats, the natural frequency group demonstrated dramatically greater normative mathematical performance than the probability group. This supports the importance of information formats in a more complex context than in previous studies.
Linear recursive discrete-time estimators using covariance information under uncertain observations
Authors: Seiichi Nakamori, Raquel Caballero-Águila, Aurora Hermoso-Carazo, Josefa Linares-Pérez
Venue: Signal Processing (2003)

This paper, using the covariance information, proposes recursive least-squares (RLS) filtering and fixed-point smoothing algorithms with uncertain observations in linear discrete-time stochastic systems. The observation equation is given by y(k) = γ(k)Hx(k) + v(k), where {γ(k)} is a binary switching sequence with conditional probability distribution verifying Eq. (3). This observation equation is suitable for modeling the transmission of data in multichannels as in remote sensing situations. The estimators require the information of the system matrix Φ concerning the state variable which generates the signal, the observation vector H, the crossvariance function Kxz(k,k) of the state variable with the signal, the variance R(k) of the white observation noise, the observed values, the probability p(k): P{γ(k)= 1} that the signal exists in the uncertain observation equation and the (2,2) element [P(k|j)]2,2 of the conditional probability matrix of γ(k), given γ(j).
A Study on a Road-Vehicle Communication System for the Future Intelligent Transport Systems
Authors: Kohshi Abe, Teruo Tobana, Takayuki Sasamori, Hisao Koizumi
Venue: Proceedings of the Seventh International Conference on Parallel and Distributed Systems: Workshops (2000)

This paper presents an example of a supposed future intelligent transport systems (ITS) and the results of examination of the system configuration. And, this paper proposes a road-vehicle communication system for the future ITS. As an evaluation of the proposed system, propagation characteristics of the radio link using 45GHz band millimeter-wave are examined, such as the vehicular interval for the line-of-sight communication, the received power level at the mobile station in adopting the transmitting power control and the diversity and attenuation caused by rain, which will clarify the feasibility of this system.
Techniques for Simplifying the Design of Distributed Systems
Authors: Gilbert A. Neiger
Venue:  (1988)

Distributed computing systems offer a number of advantages over centralized systems, such as the replication of data and functionality, which may result in increased performance and fault-tolerance. The design of protocols for distributed systems is more complex than for centralized systems because coordination and cooperation between the different processors can be difficult to achieve. Among the factors complicating this design are the following: lack of processor synchronization, lack of common knowledge, and processor failures. This thesis presents techniques for simplifying the design of distributed systems by addressing these three complicating factors. Processor synchronization is provided by using logical clocks as if they are real-time (and hence, perfectly synchronized) clocks. This can be done in solutions to a large class of problems. Common knowledge is simulated by timestamped common knowledge, which is identical to true common knowledge in systems with perfectly synchronized clocks. A communication primitive, called publication, is defined which achieves timestamped common knowledge, and an implementation of publications is given that uses logical clocks. When solving problems in the class characterized earlier, publications can be used as if they achieve true common knowledge. The design of fault-tolerant protocols is simplified through methods that automatically translate protocols tolerant of benign failures into ones tolerant of more severe failures. The design task is reduced to that of designing simpler protocols. 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
Rewrite systems for integer arithmetic
Authors: H. R. Walters, Hans Zantema
Venue:  (1995)

We present three term rewrite systems for integer arithmetic with addition, multiplication, and, in two cases, subtraction. All systems are ground confluent and terminating; termination is proved by semantic labelling and recursive path order.
Geometric Tools for Computer Graphics
Authors: Philip J. Schneider, David Eberly
Venue:  (2002)

:Do you spend too much time creating the building blocks of your graphics applications or finding and correcting errors? Geometric Tools for Computer Graphics is an extensive, conveniently organized collection of proven solutions to fundamental problems that you'd rather not solve over and over again, including building primitives, distance calculation, approximation, containment, decomposition, intersection determination, separation, and more.If you have a mathematics degree, this book will save you time and trouble. If you don't, it will help you achieve things you may feel are out of your reach. Inside, each problem is clearly stated and diagrammed, and the fully detailed solutions are presented in easy-to-understand pseudocode. You also get the mathematics and geometry background needed to make optimal use of the solutions, as well as an abundance of reference material contained in a series of appendices.KEY FEATURES: * Filled with robust, thoroughly tested solutions that will save you time and help you avoid costly errors.* Covers problems relevant for both 2D and 3D graphics programming.* Presents each problem and solution in stand-alone form allowing you the option of reading only those entries that matter to you.* Provides the math and geometry background you need to understand the solutions and put them to work.* Clearly diagrams each problem and presents solutions in easy-to-understand pseudocode.* Resources associated with the book are available at the companion Web site.Author Biography: Philip Schneider leads a modeling and dynamic simulation software group at Walt Disney Feature Animation. Prior to that, his work at Apple and Digital Equipment Corporation in 3D graphics ranged from low-level interfaces to graphics libraries and interactive applications. He holds an M.S. in Computer Science from the University of Washington.Dave Eberly is the president of Magic Software, Inc., a company known for its free source code and documentation for computer graphics, image analysis, and numerical methods. Previously, he was the director of engineering at Numerical Design Limited, the company responsible for the real-time 3D game engine, NetImmerse. His background includes a B.A. in mathematics from Bloomsburg University, M.S. and Ph.D. degrees in mathematics from the University of Colorado at Boulder, and M.S. and Ph.D. degrees in computer science from the University of North Carolina at Chapel Hill. Dave is author of 3D Game Engine Design, co-author with Philip Schneider of Geometric Tools for Computer Graphics, and author of the forthcoming Game Physics (Spring 2003).
Adaptive spectrogram vs. adaptive pseudo-Wigner-Ville distribution for instantaneous frequency estimation
Authors: S. Chandra Sekhar, T. V. Sreenivas
Venue: Signal Processing (2003)

To estimate the instantaneous frequency (IF) using the peak of the spectrogram, we use an approach that automatically adapts the window length to the changes in IF and tracks it better than a fixed window approach. An adaptive window-based time-frequency representation is more useful for tracking events in time and frequency. The peak of the spectrogram obtained using the adaptive window length algorithm is used as an IF estimator and its performance in the presence of multiplicative and additive noise is studied. The performance is compared with that of pseudo-Wigner-Ville distribution (Ps.WVD). Both analytically and experimentally, adaptive spectrogram was found to be more robust than adaptive Ps.WVD.
An Optimal Algorithm for Hyperplane Depth in the Plane
Authors: Langerman Stefan, Steiger William
Venue:  (1999)

Given a set of $n$ hyperplanes $h_1,\ldots,h_n \in R^d$ the hyperplane depth of a point $P\in R^d$ is the minimum number of hyperplanes that a ray from $P$ can meet. The {\em hyperplane depth} of the arrangement is the maximal depth of points $P$ not in any $h_i$. We give an optimal $O(n\log{n})$ deterministic algorithm to compute the hyperplane depth of an arrangement in dimension $d=2$.
Elements of Relational Database Theory
Authors: Paris C. Kanellakis
Venue:  (1989)

The goal of this paper is to provide a systematic and unifying introduction to relational database theory, including some of the recent developments in database logic programming. The first part of the presentation covers the two basic components of the relational data model: its specification component, that is the database scheme with dependencies, and its operational component, that is the relational algebra query language. The choice of basic constructs for specifying the semantically meaningful databases and for querying them is justified through an in-depth investigation of their properties. Some important research themes are reviewed in this context: the analysis of the hypergraph syntax of a database scheme and the extensions of the query language using deduction or universal relation assumptions. The subsequent parts of the presentation are structured around the two fundamental concepts illustrated in the first part, dependencies and queries. The main themes of dependency theory are implication problems and applications to database scheme design. Queries are classified in a variety of ways, with emphasis on the connections between the expressibility of query languages, finite model theory and logic programming. The theory of queries is very much related to research on database logic programs, which are an elegant formalism for the study of the principles of knowledge base systems. The optimization of such programs involves both techniques developed for the relational data model and new methods for analyzing recursive definitions. The exposition closes with a discussion of how relational database theory deals with the problems of complex objects, incomplete information and database updates.
Context Query in Information Retrieval
Authors: Chi-Hung Chi, Chen Ding, Kwok-Yan Lam
Venue: Proceedings of the 14th IEEE International Conference on Tools with Artificial Intelligence (2002)

It is observed that there is an important query requirement missing for search engines. With the wide variation of domain knowledge and user's interest, a user would like to retrieve documents in which one query term is discussed in the context of another term. Based on the existing query mechanisms, what can be specified at most is the co-occurrence of multiple terms in a query. This is insufficient because the co-occurrence of two terms does not necessarily mean that one is discussed in the context of the other. In this paper we propose the context query for web search. A new query operator, called the 'in' operator, is used to specify the context inclusion between two terms. Heuristics rules to identify context inclusion are suggested and implementation of 'in' operator in search engines is proposed. Results show that both the precision and ranking relevance of web search are improved significantly.
Scheduling support for multicasting sessions in broadband communication networks
Authors: K. Sheta, M. Singhal
Venue: Proceedings of the 6th International Conference on Computer Communications and Networks (1997)

Multimedia applications require support from the underlying broadband network at the end-to-end communication level. Multicasting is an important paradigm of end-to-end communication. The root node of a multicasting session is responsible for controlling the session including monitoring, maintenance, and the implementation of the multicasting protocol. The job that controls the multicasting session executes as a group of tasks at the root node of a multicasting tree. The scheduling scheme at the root node should give support to a multicasting session by improving the completion time of the jobs controlling the multicasting session, hence increasing throughput and the probability of admitting new multicast sessions. We model the tasks that carry out the multicasting session monitoring and maintenance as a fork-join job executing on a multiprocessor system. We assume that an executing task blocks for device I/O as a part of the activities associated with sending and receiving data packets. We develop two analytic models for scheduling a session control job on a multiprocessor system. The first allows incoming job tasks to multiplex processors with existing tasks of another multicasting session; the other model schedules a task of the incoming job to an idle processor. We assume that the overhead of rescheduling a task to another processor is large. We compare the performance of both models and show the range of conditions under which a model outperforms the other. The results can be used in the design of an adaptive scheduler that uses both models to improve throughput and the probability of admitting new multicast sessions.
A Best-Effort Communication Protocol for Real-Time Broadcast Networks
Authors: Lakshmi Ramaswamy, Binoy Ravindran
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

In this paper, we present a best-effort communication protocol called ABA, that seeks to maximize aggregate application benefit and deadline-satisfied ratio of asynchronous real-time distributed systems that use CSMA/DDCR broadcast networks. ABA considers an application model where end-to-end timeliness requirements of trans-node application tasks are expressedusing Jensen's benefit functions. Furthermore, the protocol assumes that the application is designed using CSMA/DDCR feasibility conditions that is driven by a "best" possible estimate of upper bounds on message arrival densities that is possible at design-time. When such design-time postulations get violated at run-time, ABA directs message traffic so that messages that will increase applications' aggregate benefit are only transmitted, buffering others, until such time when the workloads respect their design-time postulated values. To study the performance of ABA, we consider a previously studied algorithm called RBA* as a baseline algorithm. Our experimental results indicate that ABA yields higher aggregate benefit and higher deadline-satisfied ratio than RBA* when message arrival densities increase at faster rates or at the same rates as that of process execution latencies due to the dynamics of the workload.
Addressing organisational and societal concerns: an application of critical systems thinking to information systems planning in Colombia
Authors: Rodrigo Córdoba, Gerald Midgley
Venue: Critical reflections on information systems: a systemic approach (2003)

Most current information systems (IS) planning methodologies are focused on achieving "successful' plans, i.e., plans that provide competitive advantage, can be implemented in a given period of time, and that solve the problems of information needs by taking advantage of the latest technologies available. Concerns are technology and business driven and focus on how to get the maximum profit for organisations from investing in information systems. However, this relatively narrow focus can be problematic, especially in developing countries, where the social contexts of IS implementation may require a different primary focus. This chapter presents a methodology for IS planning based on critical systems thinking--an approach that encourages the critical analysis of stakeholder understandings of social contexts prior to the selection and/or design of planning methods. The methodology presented in this chapter uses a combination of the systems theories of autopoiesis and boundary critique, which deepen our understanding of what it means to reflect on participation, values, and social concerns during IS planning. In the course of applying the methodoloy in a project in Colombia, an issue arose of the ethics of the practitioner. To address this issue, following completion of the project, we sought to enhance critical systems thinking with Foucault's notions of power and ethics, which offer interesting alternatives for practitioner self-reflection. Implications for IS planning are derived from this perspective on ethics and power.
Toward a Recommended Practice for Architectural Description
Authors: W. Ellis, R. Hilliard, T. Saunders, P. Poon, D. Rayford, B. Sherlund, R. Wade
Venue: Proceedings of the 2nd IEEE International Conference on Engineering of Complex Computer Systems (1996)

The Architecture Planning Group (APG) was chartered by IEEE's Software Engineering Standards Committee (SESC) to set a direction for incorporating architectural thinking into IEEE standards. In this paper, we present a framework for architectural thinking and use it to review existing architectural practices; summarize the work of the APG and its recommendations; and provide the rationale for those recommendations.
Parallel Programming Languages: Do They Meet the Needs of Scientists and Engineers?
Authors: Cherri M. Pancake, Donna Bergmark
Venue:  (1990)

Although computer scientists use parallel programming languages to model concurrency, scientists and engineers approach parallelism with a different objective. The physical world they model is inherently parallel, but scientific programmers have become accustomed to using sequential techniques for its study. It is the ability to handle massive amounts of data that motivates their conversion to parallelism. This report considers the current state of parallel programming languages from the perspective of scientists and engineers. It reviews the problem-solving strategies commonly employed by scientific programmers and compares them with the conceptual models for parallelism supported by high-level programming languages available to the general user community. The fact that existing languages were designed and implemented by members of the computer science profession is reflected in the prevalence of features representing that community''s view of parallelism. Consequently, scientific programmers are unlikely to find language models that map cleanly to their problem-solving approaches.
A Client Caching Scheme for Interactive Video-on-Demand
Authors: Philip Branch, Greg Egan, Bruce Tonkin
Venue: Proceedings of the 7th IEEE International Conference on Networks (1999)

Video-on-demand trials at Monash University have shown that video in educational applications is used in a highly interactive fashion and that during a single session a significant proportion of video is examined more than once. We propose a caching scheme where video, once retrieved from the server, is cached locally on the client for the remainder of the session. We use statistics of reuse gathered during our trials to show that caching could result in bandwidth savings of up to 36%. In designing cache management schemes, an understanding of the nature of reuse is useful. We obtain this through an analysis of interactive jumps. We show that the distance of interactive jumps and the time between them are both log normally distributed, and not, as has commonly been assumed, exponentially distributed
Languages Simultaneously Complete for One-Way and Two-Way Log-Tape Automata
Authors: Juris Hartmanis, Stephen R. Mahaney
Venue:  (1980)

In this paper we study languages accepted by nondeterministic $\log n$-tape automata which scan their input only once and relate their computational power to two-way, $\log n$-tape automata. We show that for the one-way, $\log n$-tape automata the nondeterministic model (1-NL) is computationally much more powerful than the deterministic model (1-L); that under one-way, $\log n$-tape reductions there exist natural complete languages for these automata and that the complete languages cannot be sparse. Furthermore, we show that any language complete for nondeterministic one-way $\log n$-tape automata (under 1-L reductions) is also complete for the computationally more powerful nondeterministic two-way, $\log n$-tape reductions. Therefore, for all bounds $T(n),T(n \geq \log n$, the deterministic and nondeterministic $T(n)$-tape bounded computations collapse if the nondeterministic one-way $\log n$-tape computations can be carried out by two-way deterministic $\log n$-tape automata.