ppxscal/embedding_network huggingface dataset:
The Trajectory Analysis of Hidden Markov Model
Authors: Chee W Loke
Venue:  (1995)

Recently, hidden Markov modelling (HMM) has been widely used in many state-of- the-art speech recognition systems. An hidden Markov model is a doubly stochastic process with an underlying stochastic process that is not observable. The performance by the current techniques is still far from that achieved by human beings. In order to investigate this problem, a graphical interpretation of the speech feature vectors and the HMM was pursued. A graphical tool called fview was developed to displayed the trajectories of speech feature vectors. An additional feature was added to allow a graphical presentation of the hidden Markov models (HMMs). This program allows us visually investigate the relationship between the speech feature vectors and the corresponding states of the HMM. By this method, some hidden parts of the model were revealed. Firstly, the speech utterances were transformed into speech feature vectors and the trajectories displayed on a two dimensional space. The hidden Markov models were also displayed on the same two dimensional speech feature space. By visual examination, we think that the states of the HMM are related to sustained sounds. Therefore, the minimum number of states required in the continuous HMM is related to the number of phonemes in the word to be modelled. In the semi-continuous HMM, it is likely that the probability density functions also model distinct phonemes. Finally, some techniques were proposed to model the transitional trajectories between states, such as nonstationary-state hidden Markov model.
Compile/Run-time Support for Threaded MPI Execution on Multiprogrammed Shared Memory Machines
Authors: Hong Tang, Kai Shen, Tao Yang
Venue:  (1999)

MPI is a message-passing standard widely used for developing high-performance parallel applications. Because of the restriction in the MPI computation model, conventional implementations on shared memory machines map each MPI node to an OS process, which suffers serious performance degradation in the presence of multiprogramming, especially when a space/time sharing policy is employed in OS job scheduling. In this paper, we study compile-time and run-time support for MPI by using threads and demonstrate our optimization techniques for executing a large class of MPI programs written in C. The compile-time transformation adopts thread-specific data structures to eliminate the use of global and static variables in C code. The run-time support includes an efficient point-to-point communication protocol based on a novel lock-free queue management scheme. Our experiments on SGI Origin 2000 show that the MPI execution optimized by using the proposed techniques is competitive with SGI''s native MPI implementation in dedicated environments, and has great performance advantages with upto 23-fold improvement in multiprogrammed environments.
Entwicklungsstand des Qualitaetsmanagements von Informationssystemen: Eine empirische Studie in grossen Unternehmen in der Schweiz
Authors: Kurt Bauknecht, Christian Brauchle, Joachim Kreutzberg, Makaya Made
Venue:  (1998)

Informationssystem-(IS-)Qualitaetsmanagement hat die Aufgabe, IS- Prozesse und IS-Produkte anforderungsgerecht zu gestalten. Im Herbst 1997 wurde am Institut fuer Informatik der Universitaet Zuerich eine schriftliche Umfrage bei den 140 groessten schweizerischen Unternehmen durchgefuehrt mit dem Ziel, den Entwicklungsstand des Qualitaetsmanagements von Informationssysteme in der Unternehmenspraxis festzustellen. Es wurden die Gruende fuer mangelnde Qualitaet von Informationssystemen ermittelt, die Entwicklung des qualitaetsorientierten Informatik-Controlling analysiert, die Bedeutung von mehreren Instrumenten fuer eine Qualitaetsverbesserung erfasst und die in der Unternehmenspraxis erzielten Verbesserungen durch den Einsatz eines Qualitaetsmanagementsystems erfragt. Einige wichtige Ergebnisse sind die folgenden: + Zeit- und Personalmangel sind der wichtigste Grund fuer mangelnde Qualitaet der im Unternehmen eingesetzten Informationssysteme. + Der Grossteil der Unternehmen ist mit ihrem Informatik-Controlling sehr zufrieden (Vergleich zu einer Untersuchung vor vier Jahren). + Standards sind das wesentliche Instrument fuer eine verbesserte IS- Qualitaet + IS-Qualitaetsmanagement erhoeht die Transparenz im Unternehmen deutlich. Das IS-Qualitaetsmanagement weist aber noch deutliche Defizite auf, die in Zukunft durch eine verbesserte Integration in die Informatik oder durch verbesserte Unterstuetzung durch das Controlling behoben werden koennen.
Generic Texture Analysis Applied to Newspaper Segmentation
Authors: Paul S Williams, Mike Alder
Venue:  (1995)

This paper deals with the segmentation of grey-scale newspaper images into the distinct regions of text, picture and background. Feature vectors are obtained from the image by analysing localised textual characteristics and textual variation. Analysis is performed in a generic way making few contextual assumptions. The contrast, size, orientation and resolution of the image are accounted for by a combination of this feature extraction process and subsequent parameterisations. Given such implicit invariances we are able to perform an initial point based classification through the use of a modified quadratic neural network. The use of a simple flood fill based algorithm allows the successful segmentation of newspaper images into distinct rectangular regions. Results of newspaper segmentation show the effectiveness of these methods. Future work will be based on the local processing performed here and its suggested similarity to the behaviour of neurons in the human visual system.
Recognition of Printed Digits using Zernike or Orthogonal Fourier-Mellon Moments
Authors: Patrick C Hew, Mike Alder
Venue:  (1997)

We recognise printed digits in greyscale images by Zernike or Orthogonal Fourier-Mellon moments. We consider image preprocessing for calculation, the selection of appropriate moments for recognition, the validity of Gaussian models for classification, and resistance to noise.
SPEED:A Real-Time Protocol for Sensor Networks
Authors: Tian He, John A. Stankovic, Chenyang Lu, Tarek Abdelzaher
Venue:  (2002)

In this paper, we present a real-time communication protocol, called SPEED, for sensor networks. The protocol provides three types of real-time communication services, namely, real-time unicast, real-time area-multicast and real-time area-anycast. SPEED is specifically tailored to be a stateless, localized algorithm with minimal control overhead. End-to-end real-time communication guarantees are achieved using a novel combination of feedback control and non-deterministic QoS-aware geographic forwarding with a bounded hop count. SPEED is a highly efficient and scalable protocol for the sensor networks where node density is high while the resources of each node are scarce. Theoretical analysis and simulation experiments are provided to validate our claims.
Planned Disconnections for Mobile Databases
Authors: J. Holliday, D. Agrawal, A. E Abbadi
Venue:  (2000)

As mobility permeates todays computing environment, we envision application infrastructures that will increasingly use mobile technologies. Traditional database applications will need to integrate mobile entities: people and computers. In this paper, we develop a distributed database framework for mobile environments. A key requirement in such an environment is to support frequent connection and disconnection of database sites.
What (Else) Should CS Educators Know?
Authors: J. Gal-Ezer, D. Harel
Venue:  (1996)

We address a variety of issues that pertain to the background needed for teaching computer science. We have in mind both the high-school and the college/university levels. Besides the obvious prerequisite of thoroughly mastering the core topics of computer science, which should be enhanced by a comprehensive bird''s-eye view of the entire field, we claim that a good computer science educator must be acquainted with a significant body of additional material. This ranges from some historical and philosophical aspects, through various curricula and teaching methods, to the problematics of teaching specific topics. Much of this material, which should be of interest to computer science people in general, can be organized into an elective course, to be offered as part of an undergraduate computer science program or in a special teachers'' certification program.
Extraction of Speech Signal in the Presence of a Musical Note Signal Using the GRNN
Authors: K. Chong, Roberto Togneri
Venue:  (1996)

This paper presents the methodology of extracting a speech signal in the presence of a musical note signal using the GRNN (General Regression Neural Network). An overview of GRNN is presented first, followed by preliminary simulations. Results of extracting speech in the presence of a flute and a cello note are also presented.
Design optimization of seismic-resistant steel frames
Authors: H. Moharrami, S. A. Alavinasab
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

In this paper the general formulation of minimum weight design of two-dimensional steel frames under seismic loading is presented. "Equivalent static loading" scheme has been used for determining seismic loading. The design problem is formulated in the form of a standard optimization problem in which the design requirements have been treated as optimization constraints. The Optimality Criteria (OC) method has been modified and improved for simultaneous identification of active set of constraints and calculation of corresponding Lagrange multipliers. The modification has resulted in rapid convergence of the method, which is promissing in optimal design of structures under varying loading. Two examples have been provided to show the procedure of design optimization of seismic-resistant frames and the performance and capability of the proposed algorithm.
Subgrade modulus for laterally loaded piles
Authors: W. D. Guo
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

Closed-form solutions for laterally loaded piles have been established recently, accounting for various head and base conditions. The solutions are based on load transfer approach by simplifying the pile-soil interaction as independent springs along the pile shaft and at the pile base. The key of the approach is the determination of the subgrade modulus for the springs. Although a few expressions originally developed for beam analysis were used for the determination, the usage has not been rigorously verified. In this paper, the rationality of the usage has been examined in comparison with various numerical results available. Particularly the accuracy and sufficiency of the load transfer approach and the coupling effect has been explored in detail. Rigorous expressions for lateral pile analysis, and the determination of subgrade modulus, and the coupling effect are provided.
DYNAMIC CONSTRAINED DELAUNEY TRIANGULATION AND APPLICATION TO MULTICHIP MODULE LAYOUT (M.S. Thesis)
Authors: Yizhi Lu
Venue:  (1991)

The *Voronoi diagram* is a partition of a set S of N points in a plane, such that each region is the locus of the points (x, y) closer to a point of S than to any other point of S. If no four points are co-circular, the *Delaunay triangulation* is the straight-line dual of the Voronoi diagram. The triangulation may be *constrained*, that is, a set of straight-line segments may be prespecified. This thesis presents some characteristics of constrained Delaunay triangulation and introduces a set of numerically stable algorithms for incremently constructing and updating constrained Delaunay triangulation. The dynamic constrained Delaunay triangulation algorithms have been implemented in a layout system for multichip modules. It has been used as the underlying data representation for rubber-band sketch, a topological routing for one layer. We have proved the O(n log n) expected running time for the Delauney triangulation algorithm.
Backward Error Estimates for Toeplitz and Vandermonde Systems
Authors: Jim M. Varah
Venue:  (1991)

b$, it is of interest to find nearby systems with $\overline{x}$ as exact solution, and which have the same structure as A. In this paper, we show that the distance to these nearby structured systems can be much larger than for the corresponding general perturbation for Toeplitz and Vandermonde systems. In fact, even the correctly rounded solution $\hat{x}$ may require a structured perturbation of $O(\eta\parallel\hat{x}\parallel)$, not $O(\eta)$ as might be expected.
HOMPACK: A Suite of Codes for Globally Convergent Homotopy Algorithms
Authors: Layne T. Watson, Stephen C. Billups, Alexander P. Morgan
Venue:  (1990)

There are algorithms for finding zeros or fixed points of nonlinear systems of equations that are globally convergent for almost all starting points, i.e., with probability one. The essence of all such algorithms is the construction of an appropriate homotoppy map and then tracking some smooth curve in the zero set of this homotopy map. HOMPACK provides three qualitatively different algorithms for tracking the homotopy zero curve: ordinary differential equation based, normal flow, and augmented Jacobian matrix. Separate routines are also provided for dense and sparse Jacobian matrices. A high level driver is included for the special case of polynomial systems.
Orientation-Based Representations of Shape and Attitude Determination
Authors: Li Ying
Venue:  (1993)

The three rotational degrees of freedom between the coordinate system of a sensed object and that of a viewer define the attitude of the object. Orientation-based representations record 3-D surface properties as a function of position on the unit sphere. All orientation-based representations considered share a desirable property: the representation of a rotated object is equal to the rotated representation of the object before rotation. This makes the orientation-based representations well-suited to the task of attitude determination. The mathematical background for orientation-based representations of shape is presented in a consistent framework. Among the orientation-based representations considered, the support function is one-to-one for convex bodies, the curvature functions are one-to-one for convex bodies up to a translation and the radial function is one-to-one for starshaped sets. Using combinations of the support function and the curvature functions for convex bodies, the problem of attitude determination is transformed into an optimization problem. Previous mathematical results on the radial function for convex objects are extended to starshaped objects and the problem of attitude determination by the radial function also is transformed into an optimization problem. Solutions to the optimization problems exist and can be effectively computed using standard numerical methods. A proof-of-concept system has been implemented and experiments conducted both on synthesized data and on real objects using surface data derived from photometric stereo. Experimental results verify the theoretical solutions. Novel contributions of the thesis include: the representation of smooth convex objects by the support function and curvature functions; the definition of a new orientation-based representation for starshaped sets using the 3-D radial function; and solutions to the 3-D attitude determination problem using the aforementioned representations. In particular, the scope of orientation-based representations has been extended, both in theory and in practice, from convexity to starshapedness.
The Public Shared Objects Run-Time System
Authors: Stefan Lupke, Jurgen W. Quittek, Torsten Wiese
Venue:  (1995)

Public Shared Objects (PSO) is an attempt to offer advantages of Virtual Shared Memory for distributed memory parallel computers without a significant loss of perform ance. Shared data structures are distributed via the network to processing nodes and may exceed the capacity of local memory. Provided Access Objects hide access latency and reduce communication bandwidth requirement. PSO is a portable software solution extending the C++ programming language. It has been implemented for the PARIX software environment and is available for parallel computers based on Transputers or PowerPC processors.
Routing optimization in corporate networks by evolutionary algorithms
Authors: Thomas Bäck, Claus Hillermeier, Jörg Ziegenhirt
Venue: Advances in evolutionary computing: theory and applications (2003)

The purpose of the research reported in this chapter is to meet the increasing and rapidly changing communication demands in a private telecommunication network. The goal is to improve the performance of a telecommunication system just by changes in its software components. The network topology and the trunk capacities are viewed as fixed parameters, because a change in these components is very expensive. The algorithm of how to use this network is stored in a routing table that consists of alternative paths between the nodes that are supposed to be connected. So the goal of the evolutionary algorithm is to find a routing table that increases the performance of the network by reducing the probability of end-to-end-blocking. The investigated non-hierarchical networks require a fixed alternate routing (FAR) with sequential office control (SOC). The chapter presents a new approach based on evolutionary algorithms to solve this problem.
Using (n-1)-process Election to Solve N-process Election
Authors: James H. Anderson
Venue:  (1989)

We present a solution strategy for N-process election in which a leader is chosen based upon the results of a number of (N-1)-process elections. We show that the existence of such a solution depends on the constraints that are placed on the (N-1)-process elections.
Localizing Failures in Distributed Synchronization
Authors: Manhoi Choy, Ambuj K. Singh
Venue:  (1993)

We investigate the fault-tolerance of distributed algorithms in asynchronous message passing systems with undetectable process failures. We introduce failure locality as a measure of the fault-tolerance of distributed algorithms. This measure captures the general idea of allowing part of a system to continue to function despite the failure of other parts of the system. We concentrate on two problems, the dining philosophers problem and the committee coordination problem, and present algorithms with an optimal failure locality.
Analysis of a Recurrence Arising from a construction for Non-Blocking Networks
Authors: Nicholas Pippenger
Venue:  (1993)

Define f on the integers n < 1 by the recurrence f(n) = min{n, min 2f(m) + 3f(n/m)}. m|n The function f has f(n) = n as its upper envelope, attained for all prime n. Our goal in this paper is to determine the corresponding lower envelope. We shall show that this has the form f(n) ~ C(log n)^(1+1/g) for certain constants g and C, in the sense that for any epsilon < 0, the inequality f(n) >= (C + epsilon)(log n)^(1 + 1/g) holds for infinitely many n, while f(n) >= (C - epsilon)(log n)^(1 + 1/g) holds for only finitely many. In fact, g = 0.7878.... is the unique real solution of the equation 2^(-g) + 3^(-g) = 1, and C = 1.5595... is given by the expression _ _ 1/g | -g g -g g | g | 2 log 2 + 3 log 3 | |_ _| C = -------------------------------------------------------------------------- _ __ __ _ 1/g | -g g+1 -g \ g+1 \ g+1 | (g+1) | 15 log (5/2) + 3 /_ log ((k+1)/k) + /_ log ((k+1)/k) | |_ 5 >= k >= 7 8 >= k 1 with the reals x < 1 in the above recurrence: f0(x) = min{x, inf 2f0(y) + 3f0(x / y)} 1 > y > x We shall show that f0(x) ~ C0(log x)^(1+1/g), where C0 = 1.5586... is given by _ _ 1/g | -g -g -g -g | 1 + 1/g C0 = 6e | 2 log 2 + 3 log 3 | (g / (g + 1)) |_ _| and is smaller than C by a factor of 0.9994...
performance Characteristics of the Dynamic Data Cube
Authors: S. Geffner, D. Agrawal, A. E Abbadi
Venue:  (1999)

Range sum queries on data cubes are a powerful tool for analysis. A range sum query applies an aggregation operation (e.g., SUM, AVERAGE) over all selected cells in a data cube, where the selection is specified by providing ranges of values for numeric dimensions. We present the Dynamic Data Cube, a new approach to range sum queries which provides efficient performance for both queries and updates, which handles clustered and sparse data gracefully, and which allows for the dynamic expansion of the data cube in any direction.
Implementation of B-Trees Using Dynamic Address Computation
Authors: H. R Hartson, Raymond T. West,  Jr.
Venue:  (1990)

The B-tree is probably the most popular method in use today for indexes and inverted files in database management systems. The traditional implementation for a B-tree uses many pointers (more than one per key), and which can directly affect the performance of the B-tree. A general method of file organization and access (called Dynamic Address Computation) has been described by Cook that can be used to implement B-trees using no pointers. A minimal amount of storage (in addition to the keys) is required. This paper gives a detailed description of Direct Address Computation and the resulting system is analyzed, leading to the conclusion that, while the approach results in a simple implementation of B-trees, more work is required to achieve performance for large B-trees.
Using Mobile Extensions to Support Disconnected Services
Authors: Mike Dahlin, Bharat Chandra, Lei Gao, Amjad Khoja, Amol Nayate, Asim Razzaq, Anil Sewani
Venue:  (2000)

This paper examines the design and implementation of mobile extensions, a distributed operating system abstraction for supporting disconnected access to dynamic distributed services. The goal of mobile extensions is to make it as easy for service providers to deploy services that make use of caching, hoarding, asynchronous messaging, and application- level adaptation to cope with mobility, network failures, and server failures. We identify resource management as a crucial problem in this environment and develop a novel popularity-based resource management policy and demonstrate that under web service workloads it allocates resources nearly as efficiently as traditional schedulers, while under workloads with more aggressive resource users, it provides much stronger performance isolation. Overall, we find that for the four web service workloads we study, mobile extensions can reduce failures by as much as a factor of 5.9 to a factor of 16.7 for those applications able to provide tolerable service when disconnected.
Noisy Aerodynamic Response and Smooth Approximations in HSCT Design
Authors: Anthony A. Giunta, J. Dudley, Robert Narducci, Bernard Grossman, Robert T. Haftka, William H. Mason, Layne T. Watson
Venue:  (1994)

Convergence difficulties were encountered in our recent efforts towards a combined aerodynamic-structural optimization of the High Speed Civil Transport (HSCT). The underlying causes of the convergence problems were traced to numerical noise in the calculation of aerodynamic drag components for obstacles to convergence. The first technique employed a sequential approximation optimization method which used large initial move limits on the design variables. This helped dislodge the optimizer out of the local minima in the design space created by the noisy drag data. The second method utilized the aircraft. Two techniques were developed to circumvent the response surface methods to construct smooth approximations to the noisy data. The response surfaces were formed by analyzing several individual HSCT configuration and then fitting polynomial functions to selected objective function data. A simplified example design problem was used to demonstrate the response surface technique and to investigate various other issues relating to the construction of the response surfaces.