ppxscal/embedding_network huggingface dataset:
Trust-Region Interior-Point SQP Algorithms for a Class of Nonlinear Programming Problems
Authors: J. E. Dennis, Matthias Heinkenschloss, Luís N. Vicente
Venue: SIAM Journal on Control and Optimization (1998)

In this paper, a family of trust-region interior-point sequential quadratic programming (SQP) algorithms for the solution of a class of minimization problems with nonlinear equality constraints and simple bounds on some of the variables is described and analyzed. Such nonlinear programs arise, e.g., from the discretization of optimal control problems. The algorithms treat states and controls as independent variables. They are designed to take advantage of the structure of the problem. In particular they do not rely on matrix factorizations of the linearized constraints but use solutions of the linearized state equation and the adjoint equation. They are well suited for large scale problems arising from optimal control problems governed by partial differential equations.The algorithms keep strict feasibility with respect to the bound constraints by using an affine scaling method proposed, for a different class of problems, by Coleman and Li [SIAM J. Optim., 6 (1996), pp. 418--445] and they exploit trust-region techniques for equality-constrained optimization. Thus, they allow the computation of the steps using a variety of methods, including many iterative techniques.Global convergence of these algorithms to a first-order Karush--Kuhn--Tucker (KKT) limit point is proved under very mild conditions on the trial steps. Under reasonable, but more stringent, conditions on the quadratic model and on the trial steps, the sequence of iterates generated by the algorithms is shown to have a limit point satisfying the second-order necessary KKT conditions. The local rate of convergence to a nondegenerate strict local minimizer is q-quadratic. The results given here include, as special cases, current results for only equality constraints and for only simple bounds.Numerical results for the solution of an optimal control problem governed by a nonlinear heat equation are reported.
A preliminary comparison of body-wearable computers to modern audio equipment in a microgravity environment
Authors: Matthew Dooris, Michael Moorman, Bryan Gregory, Marilyn Brown Heather Wright
Venue: ACM SIGCHI Bulletin (2000)

The capabilities of body-wearable computers (BWC) and modern audio equipment were compared in a micro-gravity environment. In the experiment carried out, the speed of performance on timed tasks was compared for BWC and the audio playback devices currently used by astronauts. The BWC provided faster performance times than audio equipment when used in a micro-gravity environment. In addition, the BWC was found to provide faster performance times in normal gravity than in zero gravity.
Cooperative Query Answering with GeneralizedQuantifiers
Authors: Antonio Badia
Venue: Journal of Intelligent Information Systems (1999)

The use of Generalized Quantifiers in query languages was introduced independently in (Hsu and Parker, 1995&semi; Gyssens et al., 1995). In both cases it is argued that GQs make query languages more able to handle complex queries in a declarative way and provide a syntax more similar to natural language. In this paper we argue that query languages with Generalized Quantifiers can be used to produce cooperative question answering (Gaasterland et al., 1992). We introduce the Query Language with Generalized Quantifiers QLGQ and review related work in cooperative query answering, focusing on research that has direct connections with the results of this paper. Then we show how to use Generalized Quantifiers in dealing with false presuppositions, constructing justifications, and query relaxation. For each technique, we give examples that suggest that Generalized Quantifiers are better suited to the application of the technique than traditional approaches.
Threads Yield Continuations
Authors: Sanjeev Kumar, Carl Bruggeman, R. Kent Dybvig
Venue: Lisp and Symbolic Computation (1998)

Just as a traditional continuation represents the rest of a computation from a given point in the computation, a subcontinuation represents the rest of a subcomputation from a given point in the subcomputation. Subcontinuations are more expressive than traditional continuations and have been shown to be useful for controlling tree-structured concurrency, yet they have previously been implemented only on uniprocessors. This article describes a concurrent implementation of one-shot subcontinuations. Like one-shot continuations, one-shot subcontinuations are first-class but may be invoked at most once, a restriction obeyed by nearly all programs that use continuations. The techniques used to implement one-shot subcontinuations may be applied directly to other one-shot continuation mechanisms and may be generalized to support multi-shot continuations as well. A novel feature of the implementation is that continuations are implemented in terms of threads. Because the implementation model does not rely upon any special language features or compilation techniques, the model is applicable to any language or language implementation that supports a small set of thread primitives.
Low-Power Design for Real-Time Systems
Authors: Sheng-Tzong Cheng, Chia-Mei Chen, Jing-Wen Hwang
Venue: Real-Time Systems (1998)

Real-time Systems often are located in the special environments where the power consumption is a big concern. Upon presence of timing constraints, the low power design on the real-time systems has significant impact on the performance as well as the schedulability of the systems. The system developers are facing the challenges for reducing the power consumption and meeting the timing constraints in the real-time systems.This paper represents one of few attempts to address the issue of the low power design on real-time systems. We present two power reduction methods: one is at the software compilation level and the other at the operating system level. Given a real-time program, an inter-instruction power reduction technique is proposed to transform the program to another one with lower power consumption. In addition, a scheduling algorithm for real-time operating systems is proposed to reschedule real-time programs when the execution time of the programs is changed. Therefore, the proposed scheduling algorithm works together with the proposed power reduction technique to make sure all programs meet their deadlines and to improve the system schedulability. We also evaluate the performance of the proposed inter-instruction reduction method by comparing it with the cold scheduling algorithm and show that the proposed method outperforms the cold scheduling algorithm and reduces more energy power.
The future of software (invited presentation) (abstract only)
Authors: Grady Booch
Venue: Proceedings of the 22nd international conference on Software engineering (2000)

Software is the fuel of the world's new economy. Software has been used to create new markets, heal the human body, explore distant worlds, and bring individuals into community. Software transcends all political boundaries, consumes few resources in its execution, and permits the creation of new worlds with new laws of physics. At its best, software extends the human experience; at its worse, it can amplify our basest faults.And yet, the activity of engineering software falls short of what we would expect to be possible. Software development and deployment remain labor-intensive and intellectually demanding, requiring the best from developers who must play a number of different roles. There is still much friction in the process of crafting complex software; the goal of creating quality software in a repeatable and sustainable manner remains elusive to many organizations, especially those who are driven to develop in Internet time. This problem is exacerbated by the reality that, worldwide, there exists a shortage of skilled developers.In this presentation, we examine the future of software and the future of engineering software. We begin by briefly considering the past and then level-setting where we are in the present, focusing especially on the state of the practice of software development in the world today. We continue with a consideration of the technological, theoritical, economic, and social trends that are shaping the nature of software development. We conclude with a challenge for what software and software engineering can be in a frictionless environment.
Principal stress analysis in LDA measurements of the flow field downstream of 19-mm sorin bicarbon heart valve
Authors: V. Barbaro, M. Grigioni, C. Daniele, G. D'Avenio
Venue: Technology and Health Care (1998)

Heart valve replacement has become, since many years, a common surgical practice. Along with the improvement that the patients health has derived from it, however, a certain amount of risk could not be avoided, bound to the inevitable hemodynamic disturbances that an artificial device generates. A major shortcoming, often reported, is the formation of thrombus on the edge of the prosthetic valve, with a possible obstruction of the orifices through which blood should normally flow undisturbed. Hemolysis is another possible consequence of the implantation of a mechanical heart valve, generally correlated to turbulence downstream of prosthetic heart valves (PHV). As it is agreed upon by many researchers, the risk of thrombogenicity or hemolysis is higher in those valves that are more subject to promote turbulence and flow separation in the flow through them. In the following paper, we present a study of the turbulence-related shear stress downstream of a bileaflet valve of minimum size (19 mm external diameter) Sorin Bicarbon. This size was chosen, accordingly to the Food Drug Administration (FDA) draft guidance suggestion to investigate the worst case in turbulence promoted by PHVs, in order to have the highest velocity gradients and shear stresses for the FDA-stated cardiac output (6 l/min), related to maximum Reynolds number conditions. Velocity data were collected with the two-dimensional laser Doppler anemometry (LDA) technique semi; whereas this approach does not investigate directly all three components of the flow field, in the present case (bileaflet valves) it is not a limitation to the assessment of the maximum turbulence shear stress (TSS), thanks to the two-dimensional flow nature downstream of bileaflet models. Data taken in coincident mode were elaborated in order to determine the maximum shear stress in the measured points in the flow field, using the 2D Principal Stress Analysis (PSA). The consequences of a variable principal normal stress direction all along the measured profile will be illustrated in terms of differences between measured and maximum shear stresses. Results show the need to estimate the maximum values for the TSS and the direction along which it is obtained to correctly define the turbulent flow field downstream of PHVs.
Access Control and Signatures via Quorum Secret Sharing
Authors: Moni Naor, Avishai Wool
Venue: IEEE Transactions on Parallel and Distributed Systems (1998)

We suggest a method of controlling the access to a secure database via quorum systems. A quorum system is a collection of sets (quorums) every two of which have a nonempty intersection. Quorum systems have been used for a number of applications in the area of distributed systems. We propose a separation between access servers, which are protected and trustworthy, but may be outdated, and the data servers, which may all be compromised. The main paradigm is that only the servers in a complete quorum can collectively grant (or revoke) access permission. The method we suggest ensures that, after authorization is revoked, a cheating user Alice will not be able to access the data even if many access servers still consider her authorized and even if the complete raw database is available to her. The method has a low overhead in terms of communication and computation. It can also be converted into a distributed system for issuing secure signatures. An important building block in our method is the use of secret sharing schemes that realize the access structures of quorum systems. We provide several efficient constructions of such schemes which may be of interest in their own right.
Formulation of static circuit optimization with reduced size, degeneracy and redundancy by timing graph manipulation
Authors: Chandu Visweswariah, Andrew R. Conn
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

Static circuit optimization implies sizing of transistors and wires on a static timing basis, taking into account all paths through a circuit. Previous methods of formulating static circuit optimization produce problem statements that are very large and contain inherent redundancy and degeneracy. In this paper, a method of manipulating the timing formulation is presented which produces a dramatically more compact optimization problem, and reduces redundancy and degeneracy. The circuit optimization is therefore more efficient and effective. Numerical results to demonstrate these improvements are presented.
A Study of Different Class AB Log Domain First Order Filters
Authors: Abdullah T. Tola, Douglas R. Frey
Venue: Analog Integrated Circuits and Signal Processing (2000)

Several different class AB log-domain/translinear filters are compared in terms of their noise and distortion behavior using both analytical and simulation results. A few of the circuit topologies shown have not been considered before and are derived using a new theory for class AB dynamical circuits recently proposed. The study, although approximate, suggests ways in which both noise and distortion performance may be optimized by appropriate choice of circuit topology. Other practical aspects of the designs are also discussed.
Metrics in the software engineering curriculum
Authors: Everald E. Mills
Venue: Annals of Software Engineering (1999)

As a recognized discipline, software engineering traces its roots back to the 1968 NATO conference where the term was first used extensively to highlight the need for an engineering approach to the development of software. In the 30 years since that first &ldquo;software engineering&rdquo; conference, significant attempts have been made to improve the overall effectiveness of the software development process, and thus reduce the frequency and severity of software project failures. A major part of this improvement effort has been the attempt to develop quantitative measures which can be used to more accurately describe and better understand and manage the software development life cycle. Thus, many software metrics and models have been introduced during this period. In this article, we briefly trace the history of the development of software metrics and models, and then summarize the current state of the field. For discussion purposes, this entire development period is then arbitrarily divided into an Introductory Period (1971&ndash;1985), Growth Period (1985&ndash;1997) and the Current Period (1997&ndash;&quest;). The development of metrics during each of these periods is then related to the treatment of software metrics and models in software engineering curricula during that same period. Our conclusion is that software engineering curricula have indeed reflected the state of software engineering as the work in software metrics and models has progressed. Furthermore, software engineering curricula of the future should reflect the relatively mature state that software metrics have attained, by covering the basic concepts of metrics in appropriate core courses, and more advanced metrics topics in a specialized, elective metrics course.
Bounds on the Extreme Eigenvalues of Real Symmetric Toeplitz Matrices
Authors: A. Melman
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

We derive upper and lower bounds on the smallest and largest eigenvalues, respectively, of real symmetric Toeplitz matrices. The bounds are first obtained for positive-definite matrices and then extended to the general real symmetric case. They are computed as the roots of rational and polynomial approximations to spectral, or secular, equations for the symmetric and antisymmetric parts of the spectrum; this leads to separate bounds on the even and odd eigenvalues. We also present numerical results.
OPTIMISTA: state minimization of asynchronous FSMs for optimum output logic
Authors: Robert M. Fuhrer, Steven M. Nowick
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

The optimal state minimization problem is to select a reduced state machine having the best logic implementation over all possible state reductions and encodings. A recent algorithm, OPTIMIST [3], was the first general solution to this problem for synchronous FSMs. In this paper, we present the first solution for asynchronous FSMs.This paper makes two contributions. First, we introduce OPTIMISTA, a new algorithm which guarantees optimum 2-level output logic for asynchronous FSMs. In asynchronous machines, output logic is often critical: it usually determines the machine latency. The algorithm is formulated as a binate constraint satisfaction problem, which is solved using a binate solver. The second contribution is a novel alternative result: the unreduced machine itself can be used directly to obtain minimum-cardinality output logic.Thus, this paper presents two approaches: using OPTIMISTA, which simultaneously performs state and logic minimization; or using no state reduction (if output logic cardinality is of sole interest). Extensions for literal optimization, targetted to multi-level logic, are also proposed.
The MPEG-4 Multimedia Coding Standard: Algorithms, Architectures and Applications
Authors: S. Bauer, J. Kneip, T. Mlasko, B. Schmale, J. Vollmer, A. Hutter, M. Berekovic
Venue: Journal of VLSI Signal Processing Systems (1999)

The upcoming MPEG-4 standard provides new possibilities for the compression and presentation of multimedia contents. The main characteristics of MPEG-4 are the object-based coding and representation of an audio-visual scene and the ability to code objects of natural or synthetic origin. These features will enhance existing applications with new functionalities and enable standardised solutions for new applications. This paper provides an overview of the three major parts Systems, Visual and Audio of the new MPEG-4 standard, highlights implementation aspects for some envisaged types of MPEG-4 terminals and describes possible future multimedia application scenarios using MPEG-4 functionalities.
Delay asymptotics for a priority queueing system
Authors: Sanjay Shakkottai, R. Srikant
Venue: ACM SIGMETRICS Performance Evaluation Review (2000)

In this paper, we study discrete-time priority queueing systems fed by a large number of arrival streams. We first provide bounds on the actual delay asymptote in terms of the virtual delay asymptote. Then, under suitable assumptions on the arrival process to the queue, we show that these asymptotes are the same. We then consider a priority queueing system with two queues. Using the earlier result, we derive an upper bound on the tail probability of the delay. Under certain assumptions on the rate function of the arrival process, we show that the upper bound is tight. We then consider a system with Markovian arrivals and numerically evaluate the delay tail probability and validate these results with simulations.
TRBAC: a temporal role-based access control model
Authors: Elisa Bertino, Piero Andrea Bonatti, Elena Ferrari
Venue: Proceedings of the fifth ACM workshop on Role-based access control (2000)

Role-based access control (RBAC) models are receiving increasing attention as a generalized approach to access control. Roles can be active at certain time periods and non active at others; moreover, there can be activation dependencies among roles. To tackle such dynamic aspects, we introduce Temporal-RBAC (TRBAC), an extensions of the RBAC model. TRBAC supports both periodic activations and deactivations of roles, and temporal dependencies among such actions, expressed by means of role triggers, whose actions may be either executed immediately, or be deferred by an explicity specified amount of time. Both triggers and periodic activations/deactivations may have a priority associated with them, in order to resolve conflicting actions. A formal semantics for the specification language is provided, and a polynomial safeness check is introduced to reject ambiguous or inconsistent specifications. Finally, an implementation architecture is outlined.
Observations on comparing digital systems synthesis techniques
Authors: Donald E. Thomas
Venue: Proceedings of the 1985 ACM thirteenth annual conference on Computer Science (1985)

Previously, much research effort has been aimed at developing automatic design methods for the higher levels of system design. This work has centered around developing methods of representation, constraint specification, and automatic design. Specifically, methods of representing systems at the behavioral and functional block levels were developed and implemented. Around these representations, automatic design methods have been developed. This paper describes the previous research efforts, highlights their results, and makes observations on the comparison of these design methods.
Representing and Reasoning on Conceptual QueriesOver Image Databases
Authors: Mohand-Saïd Hacid
Venue: Journal of Intelligent Information Systems (2000)

The problem of content management of multimedia data types (e.g., image, video, graphics) is becoming increasingly important with the development of advanced multimedia applications. Traditional database management systems are inadequate for the handling of such data types. They require new techniques for query formulation, retrieval, evaluation, and navigation. In this paper we develop a knowledge-based framework for modeling and retrieving image data by content. To represent the various aspects of an image object's characteristics, we propose a model which consists of three layers: (1) Feature Content Layer, intended to contain image visual features such as contours, shapes, etc.&semi; (2) Object Layer, which provides the (conceptual) content dimension of images&semi; and (3) Schema Layer, which contains the structured abstractions of images, i.e., a general schema about the classes of objects represented in the object layer. We propose two abstract languages on the basis of description logics: one for describing knowledge of the object and schema layers, and the other, more expressive, for making queries. Queries can refer to the form dimension (i.e., information of the Feature Content Layer) or to the content dimension (i.e., information of the Object Layer). These languages employ a variable free notation. As the amount of information contained in the previous layers may be huge and operations performed at the Feature Content Layer are time-consuming, resorting to the use of materialized views to process and optimize queries may be extremely useful. For that, we propose a formal framework for testing containment of a query in a view expressed in our query language.
Spectral Analysis of Hermite Cubic Spline Collocation Systems
Authors: Weiwei Sun
Venue: SIAM Journal on Numerical Analysis (1999)

In this paper, we present an eigenvalue analysis of the first-order and second-order Hermite cubic spline collocation differentiation matrices with arbitrary collocation points. Some important features are explored and compared with some other discrete methods, such as finite difference methods.