ppxscal/embedding_network huggingface dataset:
Evolutionary Maximum Entropy Spectral Estimation and HeartRate Variability Analysis
Authors: S. I. Shah, L. F. Chaparro, A. El-Jaroudi, J. M. Furman
Venue: Multidimensional Systems and Signal Processing (1998)

Spectral analysis has been used extensively in heart rate variability (HRV) studies. The spectral content of HRV signals is useful in assessing the status of the autonomic nervous system. Although most of the HRV studies assume stationarity, the statistics of HRV signals change with time due to transients caused by physiological phenomena. Therefore, the use of time-frequency analysis to estimate the time-dependent spectrum of these non-stationary signals is of great importance. Recently, the spectrogram, the Wigner distribution, and the evolutionary periodogram have been used to analyze HRV signals. In this paper, we propose the application of the evolutionary maximum entropy (EME) spectral analysis to HRV signals. The EME spectral analysis is based on the maximum entropy method for stationary processes and the evolutionary spectral theory. It consists in finding an EME spectrum that matches the Fourier coefficients of the evolutionary spectrum. The spectral parameters are efficiently calculated by means of the Levinson algorithm. The EME spectral estimator provides very good time-frequency resolution, sidelobe reduction and parametric modeling of the evolutionary spectrum. With the help of real HRV signals we show the superior performance of the EME over the earlier methods.
Single-Machine Scheduling of Unit-Time Jobs with Earliness and Tardiness Penalties
Authors: Sushil Verma, Maged Dessouky
Venue: Mathematics of Operations Research (1998)

The problem of determining a schedule of jobs with unit-time lengths on a single machine that minimizes the total weighted earliness and tardiness penalties with respect to arbitrary rational due-dates is formulated as an integer programming problem. We show that if the penalties meet a certain criterion, called the Dominance Condition, then there exists an extremal optimal solution to the LP-relaxation that is integral, leading to a polynomial-time solution procedure. The general weighted symmetric penalty structure is one cost structure that satisfies the Dominance Condition; we point out other commonly found penalty structures that also fall into this category.
SIGGRAPH 98 activities and ACM/Policy 98 wrap-up
Authors: Bob Ellis
Venue: ACM SIGGRAPH Computer Graphics (1998)

This column provides a summary of our public policy activities at the SIGGRAPH 98 conference as well as a wrap-up of the ACM/Policy 98 Conference. See also http://www.siggraph.org/othercom/pubpolicy.html.
Parametric Blur Estimation Using the Generalized Cross-ValidationCriterion and a Smoothness Constraint on the Image
Authors: S. Chardon, B. Vozel, K. Chehdi
Venue: Multidimensional Systems and Signal Processing (1999)

Parametric blur estimation is proposed using the Generalized Cross-Validation Criterion (GCV) and a smoothness constraint on the image. This approach bypasses the need to identify the image AR parameters. The blur synthesis domains that may be used in the GCV criterion are compared experimentally. The criterion is then applied, in a myopic scheme, on blurred and unblurred images. Results with synthetic and real blurs are discussed.
Topological considerations of ATM networks
Authors: T. Andrew Au
Venue: International Journal of Network Management (1999)

This article considers two hierarchical routing models based on the optimization of the size of topology databases and routing complexity, respectively. Some design guidelines are also suggested for an hierarchical PNNI structure of a network topology databases and routing complexity, respectively. Some design guidelines are also suggested for an hierarchical PNNI structure of a network topology. Copyright &copy; 1999 John Wiley Sons, Ltd.
Derivation of Numerical Methods Using Computer Algebra
Authors: Walter Gander, Dominik Gruntz
Venue: SIAM Review (1999)

The use of computer algebra systems in a course on scientific computation is demonstrated. Various examples, such as the derivation of Newton's iteration formula, the secant method, Newton--Cotes and Gaussian integration formulas, as well as Runge--Kutta formulas, are presented. For the derivations, the computer algebra system Maple is used.
Generalized projection pursuit regression
Authors: Ole C. Lingjærde, Knut Liestøl
Venue: SIAM Journal on Scientific Computing (1999)

Projection pursuit regression (PPR) can be used to estimate a smooth function of several variables from noisy and scattered data. The estimate is a sum of smoothed one-dimensional projections of the variables. This paper discusses an extension of PPR to exponential family distributions, called generalized projection pursuit regression (GPPR). The proposed model allows multiple responses and nonlinear projections of the variables. Estimators are defined as minimizers of penalized cost functionals, and estimation is related to the local scoring procedure for generalized additive models (GAMs). Smooths are updated using a blockwise Gauss--Seidel (BGS) method, and convergence is shown for this procedure. The use of generalized cross validation (GCV) to estimate smoothing parameters is discussed. Experimental results are shown for two types of data.
Generating Quasi-Random Paths for Stochastic Processes
Authors: William J. Morokoff
Venue: SIAM Review (1998)

The need to simulate stochastic processes numerically arises in many fields. Frequently this is done by discretizing the process into small time steps and applying pseudorandom sequences to simulate the randomness. This paper addresses the question of how to use quasi-Monte Carlo methods to improve this simulation. Special techniques must be applied to avoid the problem of high dimensionality which arises when a large number of time steps is required. Two such techniques, the generalized Brownian bridge and particle reordering, are described here. These methods are applied to a problem from finance, the valuation of a 30-year bond with monthly coupon payments assuming a mean reverting stochastic interest rate. When expressed as an integral, this problem is nominally 360 dimensional. The analysis of the integrand presented here explains the effectiveness of the quasi-random sequences on this high-dimensional problem and suggests methods of variance reduction which can be used in conjunction with the quasi-random sequences.
Storage System and Multimedia: Classification and Extensions
Authors: Ramzi R. Yehia, Imad Mahgoub
Venue: Distributed and Parallel Databases (1999)

With the increasing processing speeds, there is a shift away from the paradigm of centralized, sequential storage systems towards distributed and network based storage systems. Further, with the new imaging and real time multimedia applications, it is becoming more than ever important to design powerful, efficient and scaleable I/O systems. In this paper, the requirements of storage subsystems in multimedia environment were presented. The storage system components relating to those requirements were analyzed. Current solutions were surveyed and classified. Then we proposed approaches to improve storage subsystem performance for multimedia. The first approach applies constrained layout currently used for single disk model to multi-disk system. The second calls for using a stripping unit that meets both media and storage system optimization criteria. The third uses a pool of buffers instead of single buffer per stream.
SPIRE: a progressive content-based spatial image retrieval engine
Authors: Chung-Sheng Li, Lawrence D. Bergman, Yuan-Chi Chang, Vittorio Castelli, John R. Smith
Venue: ACM SIGMOD Record (2000)

In this demo, we will show the implementation of a content-based SPatial Image Retrieval Engine (SPIRE) for multimodal unstructured data. This architecture provides a framework for retrieving multi-modal data including image, image sequence, time series and parametric data from large archives. Dramatic speedup (from a factor of 4 to 35) has been achieved for many search operations such as template matching, texture feature extraction. This framework has been applied and validated in solar flares and petroleum exploration in which spatial and spatial-temporal phenomena are located.
Improving the effectiveness of information retrieval with local context analysis
Authors: Jinxi Xu, W. Bruce Croft
Venue: ACM Transactions on Information Systems (TOIS) (2000)

Techniques for automatic query expansion have been extensively studied in information research as a means of addressing the word mismatch between queries and documents. These techniques can be categorized as either global or local. While global techniques rely on analysis of a whole collection to discover word relationships, local techniques emphasize analysis of the top-ranked documents retrieved for a query. While local techniques have shown to be more effective that global techniques in general, existing local techniques are not robust and can seriously hurt retrieved when few of the retrieval documents are relevant. We propose a new technique, called local context analysis, which selects expansion terms based on cooccurrence with the query terms within the top-ranked documents. Experiments on a number of collections, both English and non-English, show that local context analysis offers more effective and consistent retrieval results.
The Quantity Flexibility Contract and Supplier-Customer Incentives
Authors: Andy A. Tsay
Venue: Management Science (1999)

Consider a supply chain consisting of two independent agents, a supplier (e.g., a manufacturer) and its customer (e.g., a retailer), the latter in turn serving an uncertain market demand. To reconcile manufacturing/procurement time lags with a need for timely response to the market, such supply chains often must commit resources to production quantities based on forecasted rather than realized demand. The customer typically provides a planning forecast of its intended purchase, which does not entail commitment. Benefiting from overproduction while not bearing the immediate costs, the customer has incentive to initially overforecast before eventually purchasing a lesser quantity. The supplier must in turn anticipate such behavior in its production quantity decision. This individually rational behavior results in an inefficient supply chain. This paper models the incentives of the two parties, identifying causes of inefficiency and suggesting remedies. Particular attention is given to the Quantity Flexibility (QF) contract, which couples the customer's commitment to purchase no less than a certain percentage below the forecast with the supplier's guarantee to deliver up to a certain percentage above. Under certain conditions, this method can allocate the costs of market demand uncertainty so as to lead the individually motivated supplier and customer to the systemwide optimal outcome. We characterize the implications of QF contracts for the behavior and performance of both parties, and the supply chain as a whole.
ILE: a Java-based environment for CS courses
Authors: H. Hosny, O. Khaled, M. E. Fathalla
Venue: ACM SIGCSE Bulletin (2000)

This paper provides an overview of the Interactive Lab Environment (ILE) project and a report on its current status and future directions. ILE is the framework of a customized interactive lab environment for computing concepts and courseware that we developed for our department using Java.In essence ILE is a well-managed, networked set of resources that offers its users a collection of tools. The most significant of these tools are the flexible routes through an interactive learning environment combining the presentation of course information and notes, executable examples of learning materials, visual tools for presenting new concepts that are otherwise hard to visualize, and a quick means of communication within the academic unit. In addition to the ILE framework itself and a few course material demos, two interactive components were developed and implemented thus far, both of which are visual tools but with differing degrees of abstraction and disclosure.
Low power self-timed Radix-2 division (poster session)
Authors: Jae-Hee Won, Kiyoung Choi
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

A self-timed radix-2 division scheme for low power consumption is proposed. By replacing dual-rail dynamic circuits in non-critical data paths with single-rail static circuits, power dissipation is decreased, yet performance is maintained by speculative remainder computation. SPICE simulation results show that the proposed design can achieve 33.8-ns latency for 56-bit mantissa division and 47% energy reduction compared to a fully dual-rail version.
Digital library access for Chinese visually impaired
Authors: Robert Luk, Daniel Yeung, Qin Lu, Eric Leung
Venue: Proceedings of the fifth ACM conference on Digital libraries (2000)

This paper describes our effort to make digital libraries (on the World Wide Web or in CD-ROMs) accessible to the Chinese visually impaired via a (Web) browser. The interface has an electromagnetic braille display for touch reading, as well as a bilingual English-Chinese text-to-speech system. The interface for navigating through the Web and the web pages is presented. Apart from web navigation, Chinese data entry is difficult even for the sighted users, due to the large Chinese character set. An advanced input method designed for the Chinese visually impaired is discussed. It enables the visually impaired to formulate both Boolean-type and natural language queries.
An Efficient Parallel Algorithm for Computing the Gaussian Convolution of Multi-dimensional Image Data
Authors: Hoi-Man Yip, Ishfaq Ahmad, Ting-Chuen Pong
Venue: The Journal of Supercomputing (1999)

In this paper, we propose a parallel convolution algorithm for estimating the partial derivatives of 2D and 3D images on distributed-memory MIMD architectures. Exploiting the separable characteristics of the Gaussian filter, the proposed algorithm consists of multiple phases such that each phase corresponds to a separated filter. Furthermore, it exploits both the task and data parallelism, and reduces communication through data redistribution. We have implemented the proposed algorithm on the Intel Paragon and obtained a substantial speedup using more than 100 processors. The performance of the algorithm is also evaluated analytically. The analytical results confirming with the experimental results indicate that the proposed algorithm scales very well with the problem size and number of processors. We have also applied our algorithm to the design and implementation of an efficient parallel scheme for the 3D surface tracking process. Although our focus is on 3D image data, the algorithm is also applicable to 2D image data, and can be useful for a myriad of important applications including medical imaging, magnetic resonance imaging, ultrasonic imagery, scientific visualization, and image sequence analysis.
An Elementary Demonstration of the Existence of $s\ell(3,R)$ Symmetry for all Second-Order Linear Ordinary Differential Equations
Authors: K. S. Govinder, P. G. L. Leach
Venue: SIAM Review (1998)

All second-order linear ordinary differential equations are shown in an elementary way to possess the symmetry algebra ${s}\ell(2,R)$.
MOCHA: a self-extensible database middleware system for distributed data sources
Authors: Manuel Rodríguez-Martínez, Nick Roussopoulos
Venue: ACM SIGMOD Record (2000)

We present MOCHA, a new self-extensible database middleware system designed to interconnect distributed data sources. MOCHA is designed to scale to large environments and is based on the idea that some of the user-defined functionality in the system should be deployed by the middleware system itself. This is realized by shipping Java code implementing either advanced data types or tailored query operators to remote data sources and have it executed remotely. Optimized query plans push the evaluation of powerful data-reducing operators to the data source sites while executing data-inflating operators near the client's site. The Volume Reduction Factor is a new and more explicit metric introduced in this paper to select the best site to execute query operators and is shown to be more accurate than the standard selectivity factor alone. MOCHA has been implemented in Java and runs on top of Informix and Oracle. We present the architecture of MOCHA, the ideas behind it, and a performance study using scientific data and queries. The results of this study demonstrate that MOCHA provides a more flexible, scalable and efficient framework for distributed query processing compared to those in existing middleware solutions.
Cooperative inquiry: developing new technologies for children with children
Authors: Allison Druin
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

In todays homes and schools, children are emerging as frequent and experienced users of technology [3, 14]. As this trend continues, it becomes increasingly important to ask if we are fulfilling the technology needs of our children. To answer this question, I have developed a research approach that enables young children to have a voice throughout the technology development process. In this paper, the techniques of cooperative inquiry will be described along with a theoretical framework that situates this work in the HCI literature. Two examples of technology resulting from this approach will be presented, along with a brief discussion on the design-centered learning of team researchers using cooperative inquiry.
Nonhamiltonian 3-Connected Cubic Planar Graphs
Authors: R. E. L. Aldred, S. Bau, D. A. Holton, Brendan D. McKay
Venue: SIAM Journal on Discrete Mathematics (2000)

We establish that every cyclically 4-connected cubic planar graph of order at most 40 is hamiltonian. Furthermore, this bound is determined to be sharp, and we present all nonhamiltonian examples of order 42. In addition we list all nonhamiltonian cyclically 5-connected cubic planar graphs of order at most 52 and all nonhamiltonian 3-connected cubic planar graphs of girth 5 on at most 46 vertices. The fact that all 3-connected cubic planar graphs on at most 176 vertices and with face size at most 6 are hamiltonian is also verified.
Testing of Oscillators
Authors: Andreas Rusznyak
Venue: Journal of Electronic Testing: Theory and Applications (1999)

To guarantee correct functioning of oscillators the amplifier gain and the series resistance of the resonator constituting this module have to be tested. A method is proposed whereby the oscillator configuration remains as in application.
A Complete Efficiency Ranking of Decision Making Units in Data Envelopment Analysis
Authors: Saeid Mehrabian, Mohammad R. Alirezaee, Gholam R. Jahanshahloo
Venue: Computational Optimization and Applications (1999)

The efficiency measures provided by DEA can be used for ranking Decision Making Units (DMUs), however, this ranking procedure does not yield relative rankings for those units with 100% efficiency. Andersen and Petersen have proposed a modified efficiency measure for efficient units which can be used for ranking, but this ranking breaks down in some cases, and can be unstable when one of the DMUs has a relatively small value for some of its inputs. This paper proposes an alternative efficiency measure, based on a different optimization problem that removes the difficulties.
Shock resistant Time Warp
Authors: Alois Ferscha, James Johnson
Venue: Proceedings of the thirteenth workshop on Parallel and distributed simulation (1999)

In an attempt to cope with time-varying workload, traditional adaptive Time Warp protocols are designed to react in response to performance changes by altering control parameter configurations, like the amount of available memory, the size of the checkpointing interval, the frequency of GVT computation, fossil collection invocations, etc.\ We call those schemes ``reactive'' because all control decisions are undertaken based on historical performance information collected at runtime, and come into effect in future system states. What must be considered a drawback of this class of approaches is that Time Warp logical processes (LPs) have most likely reached a state different from the one for which the control action was established - thus inducing performance control activities which are always outdated.This paper develops environment aware, self adaptive Time Warp LPs implementing a pro-active performance control scheme, addressing the timeliness of control decisions. Opposed to reactive TW schemes, our pro-active control mechanism based on a statistical analysis of the state history periodically collected in (real) time intervals of size d, forecasts a future LP state. A performance control decision is established, that is most appropriate for the expected future LP state, i.e. the state when the corresponding control activity would become effective. Depending on the forecast quality, a pro-active scheme will presumably exhibit performance superior to re-active schemes, at least for cases where state changes in the time frame $\Delta$ are very likely. In this paper we study the ability of pro-active TW LPs, to adapt to sudden load changes, especially to abruptly occurring background workloads injected by other applications executing concurrently with the TW simulation on a network of workstations. Experimental results show that the protocol is able to capture abrupt changes in both computational and communication resource availability, justifying the title: "shock resistant Time Warp".
On the Strong Stabilizability of MIMO n-Dimensional Linear Systems
Authors: Jiang Qian Ying
Venue: SIAM Journal on Control and Optimization (1999)

A plant is strongly stabilizable if there exists a stable compensator to stabilize it. Based on some theorems in complex analysis of several variables proved in this paper, we present necessary conditions for the strong stabilizability of complex and real n-D multi-input multi-output (MIMO) shift-invariant linear plants. For the real case, the condition is a generalization of the parity interlacing property of Youla, Bongiorno, and Lu [ Automatica J. IFAC, 10 (1974), pp. 159--173] for the strong stabilizability of a real one-dimensional MIMO plant. These conditions are also sufficient for the cases of n-D plants with a single output (MISO) or with a single input (SIMO). For general n-D MIMO plants, we do not know if the conditions are sufficient or not. A useful sufficient, but not necessary, condition for the strong stabilizability of a class of n-D $(n\geq 2)$ MIMO plants is given.
n-Widths and Singularly Perturbed Boundary Value Problems
Authors: R. Bruce Kellogg, Martin Stynes
Venue: SIAM Journal on Numerical Analysis (1999)

Using the theory of n-widths, the approximability of solutions of singularly perturbed linear reaction-diffusion problems in two dimensions is quantified.