ppxscal/embedding_network huggingface dataset:
Oracles That Compute Values
Authors: Stephen Fenner, Steven Homer, Mitsunori Ogihara, Alan Selman
Venue: SIAM Journal on Computing (1997)

This paper focuses on complexity classes of partial functions that are computed in polynomial time with oracles in NPMV, the class of all multivalued partial functions that are computable nondeterministically in polynomial time. Concerning deterministic polynomial-time reducibilities, it is shown that a multivalued partial function is polynomial-time computable with k adaptive queries to NPMV if and only if it is polynomial-time computable via 2k-1 nonadaptive queries to NPMV; a characteristic function is polynomial-time computable with k adaptive queries to NPMV if and only if it is polynomial-time computable with k adaptive queries to NP; unless the Boolean hierarchy collapses, for every k, k adaptive (nonadaptive) queries to NPMV are different than k+1 adaptive (nonadaptive) queries to NPMV. Nondeterministic reducibilities, lowness, and the difference hierarchy over NPMV are also studied. The difference hierarchy for partial functions does not collapse unless the Boolean hierarchy collapses, but, surprisingly, the levels of the difference and bounded query hierarchies do not interleave (as is the case for sets) unless the polynomial hierarchy collapses.
A Low Power DSP Engine for Wireless Communications
Authors: Ingrid Verbauwhede, Mihran Touriguian
Venue: Journal of VLSI Signal Processing Systems (1998)

This paper describes the architecture and the performance of a new programmable 16-bit Digital Signal Processor (DSP) engine. It is developed specifically for next generation wireless digital systems and speech applications. Besides providing a basic instruction set, similar to current day 16-bit DSP&lsquo;s, it contains distinctive architectural features and unique instructions, which make the engine highly efficient for compute-intensive tasks such as vector quantization and Viterbi operations. The datapath contains two Multiply-Accumulate units and one ALU. The external memory bandwidth is kept to two data busses and two corresponding address busses. Still, the internal bus network is designed such that all three units are operating in parallel. This parallelism is reflected in the performance benchmarks. For example, an FIR filter of N taps will take N/2 instruction cycles compared to N for a general purpose 16-bit DSP, and it will require only half the number of memory accesses of a general purpose DSP. This efficiency is reflected in the very low MIPS requirement to implement cellular standards.
Java security
Authors: Scott Oaks
Venue:  (1998)

This essential Java 2 book covers Java's security mechanisms and teaches you how to work with them. It discusses class loaders, security managers, access lists, digital signatures, and authentication and shows how to use these to create and enforce your own security policy.
Multitask Learning
Authors: Rich Caruana
Venue: Machine Learning (1997)

Multitask Learning is an approach to inductive transfer that improves generalization by using the domain information contained in the training signals of related tasks as an inductive bias. It does this by learning tasks in parallel while using a shared representation; what is learned for each task can help other tasks be learned better. This paper reviews prior work on MTL, presents new evidence that MTL in backprop nets discovers task relatedness without the need of supervisory signals, and presents new results for MTL with k-nearest neighbor and kernel regression. In this paper we demonstrate multitask learning in three domains. We explain how multitask learning works, and show that there are many opportunities for multitask learning in real domains. We present an algorithm and results for multitask learning with case-based methods like k-nearest neighbor and kernel regression, and sketch an algorithm for multitask learning in decision trees. Because multitask learning works, can be applied to many different kinds of domains, and can be used with different learning algorithms, we conjecture there will be many opportunities for its use on real-world problems.
Analysis of Robust H2 Performance Using Multiplier Theory
Authors: Eric Feron
Venue: SIAM Journal on Control and Optimization (1997)

In this paper, the problem of determining the worst-case H2 performance of a control system subject to linear time-invariant uncertainties is considered. A set of upper bounds on the performance is derived, based on the theory of stability multipliers and the solution of an original optimal control problem. The numerical issues raised by the resulting computational problems are discussed; in particular, newly developed interior-point convex optimization methods, combined with linear matrix inequalities, apply very well to the fast and accurate solution of these problems. The new results compare favorably with prior ones. The method can be extended to other types of perturbations.
Families of Solutions of Matrix Riccati Differential Equations
Authors: M. Pavon, D. D'Alessandro
Venue: SIAM Journal on Control and Optimization (1997)

The J. C. Willems--Coppel--Shayman geometric characterization of solutions of the algebraic Riccati equation (ARE) is extended to asymmetric Riccati differential equations with time-varying coefficients. The coefficients do not need to satisfy any definiteness, periodicity, or system-theoretic condition. More precisely, given any two solutions $X_1(t)$ and $X_2(t)$ of such equation on a given interval $[t_0,t_1]$, we show how to construct a family of solutions of the same equation of the form $X(t) = (I-\pi(t))X_1(t)+\pi(t)X_2(t)$, where $\pi$ is a suitable matrix-valued function. Even when specialized to the case of $X_1$ and $X_2$ equilibrium solutions of a symmetric equation with constant coefficients, our results considerably extend the classical ones, as no further assumption is made on the pair $X_1$, $X_2$ and on the coefficient matrices.
Accelerated Inexact Newton Schemes for Large Systems of Nonlinear Equations
Authors: Diederik R. Fokkema, Gerard L. G. Sleijpen, Henk A. Van der
Venue: SIAM Journal on Scientific Computing (1998)

Classical iteration methods for linear systems, such as Jacobi iteration, can be accelerated considerably by Krylov subspace methods like GMRES @. In this paper, we describe how inexact Newton methods for nonlinear problems can be accelerated in a similar way and how this leads to a general framework that includes many well-known techniques for solving linear and nonlinear systems, as well as new ones. Inexact Newton methods are frequently used in practice to avoid the expensive exact solution of the large linear system arising in the (possibly also inexact) linearization step of Newton's process. Our framework includes acceleration techniques for the "linear steps" as well as for the "nonlinear steps" in Newton's process. The described class of methods, the accelerated inexact Newton (AIN) methods, contains methods like GMRES and GMRESR for linear systems, Arnoldi and JacDav{} for linear eigenproblems, and many variants of Newton's method, like damped Newton, for general nonlinear problems. As numerical experiments suggest, the AIN{} approach may be useful for the construction of efficient schemes for solving nonlinear problems.
Portable run-time type description for conventional compilers
Authors: Sheetal V. Kakkad, Mark S. Johnstone, Paul R. Wilson
Venue: Proceedings of the 1st international symposium on Memory management (1998)

Many useful programming language extensions and system support libraries require knowledge of the locations of fields within objects at run time. Examples include orthogonal persistent object stores, precise garbage collectors, data structure picklers, and parameter marshaling schemes.For clean and efficient implementation as libraries, these systems require run-time knowledge of in-memory layouts of data objects, which is unavailable in most traditionally compiled and linked programming languages, such as C, C++, and Ada. Even the recently standardized run-time type identification (RTTI) feature in C++ is insufficient, because it describes only language-level features of the type hierarchy and not the compiler-dependent object layout decisions.We present a facility for run-time type description, or RTTD, which extracts low-level layout information from debugging information generated by conventional compilers, and makes it available to user programs. We believe this to be the simplest and most portable approach to run-time type description, requiring no changes to existing compilers. In this paper, we describe the basic strategies and present details of our implementation for C++. We also sketch some extensions that we have implemented, including special treatment of C++'s virtual function table pointers to match persistent or foreign data objects with the actual code in a particular application.Our implementation of run-time type description is freely available. It is in regular use with multiple operating systems and compilers, in both free and commercial products, including a high-performance persistent object storage system for C++ and a real-time garbage collector.
Multiresolution Vector Quantization for Video Coding
Authors: G. Calvagno, R. Rinaldo
Venue: Multidimensional Systems and Signal Processing (1997)

In this work, we propose a coding technique that is based on the generalized block prediction of the multiresolution subband decomposition of motion compensated difference image frames. A segmentation mask is used to distinguish between the regions where motion compensation was effective and those regions where the motion model did not succeed. The difference image is decomposed into a multiresolution pyramid of subbands where the highest resolution subbands are divided into two regions, based on the information given by the segmentation mask. Only the coefficients of the regions corresponding to the motion model failure are considered in the highest resolution subbands. The remaining coefficients are coded using a multiresolution vector quantization scheme that exploits inter-band non-linear redundancy. In particular, blocks in one subimage are predicted from blocks of the adjacent lower resolution subimage with the same orientation. This set of blocks plays the role of a codebook built from coefficients inside the subband decomposition itself. Whenever the inter-band prediction does not give satisfactory results with respect to a target quality, the block coefficients are quantized using a lattice vector quantizer for a Laplacian source.
A Tight Lower Bound on the Number of Channels Required for Deadlock-Free Wormhole Routing
Authors: Ran Libeskind-Hadas
Venue: IEEE Transactions on Computers (1998)

Wormhole routing is widely employed in current generation multicomputers and the design of deadlock-free wormhole routing algorithms is an important problem. In this note, we prove a tight lower bound on the number of channels required by a broad class of deadlock-free wormhole routing algorithms. This result has applications in proving that certain topologies do not admit deadlock-free wormhole routing algorithms, as well as applications in the design and analysis of fault-tolerant wormhole routing algorithms.
A Feasibility Decision Algorithm for Rate Monotonic andDeadline Monotonic Scheduling
Authors: Yoshifumi Manabe, Shigemi Aoyagi
Venue: Real-Time Systems (1998)

Rate monotonic and deadline monotonic scheduling are commonly used for periodic real-time task systems. This paper discusses a feasibility decision for a given real-time task system when the system is scheduled by rate monotonic and deadline monotonic scheduling. The time complexity of existing feasibility decision algorithms depends on both the number of tasks and maximum periods or deadlines when the periods and deadlines are integers. This paper presents a new necessary and sufficient condition for a given task system to be feasible and proposes a new feasibility decision algorithm based on that condition. The time complexity of this algorithm depends solely on the number of tasks. This condition can also be applied as a sufficient condition for a task system using priority inheritance protocols to be feasible with rate monotonic and deadline monotonic scheduling.
Aerosol transport and diffusion data
Authors: Sol Kaufman
Venue: Proceedings of the 17th conference on Winter simulation (1985)

Various mathematical modeling approaches have been developed over the years to simulate the transport and diffusion of small particle aerosols in the atmosphere. The roles played by some important factors/mechanisms are briefly discussed, including the mean and turbulent components of the wind field, boundary conditions, particle size distribution, mode of dissemination, evaporation, and deposition. Expected-value models generally predict integrated dosage, deposition density, and aerosol &ldquo;cloud&rdquo; dimensions as functions of downwind location. Instrumented field trials of aerosol releases under various meteorological and environmental conditions can be valuable in helping to assess model validity. A literature survey identified 65 documented small particle aerosol field tests, mostly under Department of Defense auspices. Review of these tests enabled initial development of an input-output data base for selected aerosol trials. The scope and some limitations of the test data documents reviewed to date are noted. Recommendations are made, including the need for further development of stochastic aerosol modeling, to capture the highly variable nature of experimental observations.
Improved Moment-Estimation Formulas Using More Than Three Subjective Fractiles
Authors: Hon-Shiang Lau, Amy Hing-Ling Lau, Chrwan-Jyh Ho
Venue: Management Science (1998)

PERT-type subjective estimations are used in many stochastic decision models to estimate the random variables mean and standard deviation (s.d.). The approach is based on the beta-distribution assumption; also, most PERT-type formulas use only three estimated fractiles. We point out that: (i) it is desirable to consider a substantially richer set of distributions than the beta in developing PERT-type formulas; (ii) it may be beneficial to use more than three fractile-estimates in PERT-type formulas. We then develop formulas for estimating the mean and s.d. that are based on a substantially richer set of distributions than the beta and that use more than three estimated fractiles. These formulas perform better than the best currently-vailable formulas when the subjective distribution is not restricted to be beta.
Unambiguous Computation: Boolean Hierarchies and Sparse Turing-Complete Sets
Authors: Lane A. Hemaspaandra, Jörg Rothe
Venue: SIAM Journal on Computing (1997)

It is known that for any class $\tweak{\cal C}$ closed under union and intersection, the Boolean closure of ${\cal C}$, the Boolean hierarchy over $\tweak{\cal C}$, and the symmetric difference hierarchy over $\tweak{\cal C}$ all are equal. We prove that these equalities hold for any complexity class closed under intersection; in particular, they thus hold for unambiguous polynomial time (UP). In contrast to the NP case, we prove that the Hausdorff hierarchy and the nested difference hierarchy over UP both fail to capture the Boolean closure of UP in some relativized worlds. Karp and Lipton proved that if nondeterministic polynomial time has sparse Turing-complete sets, then the polynomial hierarchy collapses. We establish the first consequences from the assumption that unambiguous polynomial time has sparse Turing-complete sets: (a) $\up \seq \mbox{Low}_2$, where $\mbox{Low}_2$ is the second level of the low hierarchy, and (b) each level of the unambiguous polynomial hierarchy is contained one level lower in the promise unambiguous polynomial hierarchy than is otherwise known to be the case.
Nanites: an approach to structure-based monitoring
Authors: Kenneth J. Rodham, Dan R. Olsen,  Jr.
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (1997)

The focal point of many interactive systems is an information artifact being created and manipulated by one or more users through a user interface. The software components of such an interactive system perform their tasks relative to the data structures that represent the information artifact. System components interact with each other by changing these data and responding when relevant changes are made to them by other components. Perhaps the most difficult problem to be solved when building such data-centric systems is the monitoring problem. System components require the ability to watch for and respond to changes made to complex data structures. Previous monitoring approaches are geared toward monitoring single data items rather than entire data structures. This article describes an new monitoring approach called Nanites that is designed to simplify the task of monitoring complex data structures.
Explanation-Based Learning and Reinforcement Learning: A Unified View
Authors: Thomas G. Dietterich, Nicholas S. Flann
Venue: Machine Learning (1997)

In speedup-learning problems, where full descriptions of operators are known, both explanation-based learning (EBL) and reinforcement learning (RL) methods can be applied. This paper shows that both methods involve fundamentally the same process of propagating information backward from the goal toward the starting state. Most RL methods perform this propagation on a state-by-state basis, while EBL methods compute the weakest preconditions of operators, and hence, perform this propagation on a region-by-region basis. Barto, Bradtke, and Singh (1995) have observed that many algorithms for reinforcement learning can be viewed as asynchronous dynamic programming. Based on this observation, this paper shows how to develop dynamic programming versions of EBL, which we call region-based dynamic programming or Explanation-Based Reinforcement Learning (EBRL). The paper compares batch and online versions of EBRL to batch and online versions of point-based dynamic programming and to standard EBL. The results show that region-based dynamic programming combines the strengths of EBL (fast learning and the ability to scale to large state spaces) with the strengths of reinforcement learning algorithms (learning of optimal policies). Results are shown in chess endgames and in synthetic maze tasks.
Tools and methods for group data modeling: a key enabler of enterprise modeling
Authors: James D. Lee, Douglas L. Dean, Douglas R. Vogel
Venue: ACM SIGGROUP Bulletin (1997)

The need for tools and meeting methods to provide effective support during data model development meetings has been an elusive goal. Researchers at the University of Arizona have developed collaborative tools and methods to support groups during these meetings. This paper discusses meeting methods to support such meetings. A process is described that orchestrates the work in a way that gives non-analyst participants an ordered set of tasks that they can complete. Use of this approach with a group data modeling tool provides a means for larger groups to effectively participate during data model development and review. Users can see and contribute model content in parallel. The approach manages complexity, supports comprehension, and fosters agreement among participants.
Ergodic Control of Switching Diffusions
Authors: Mrinal K. Ghosh, Aristotle Arapostathis, Steven I. Marcus
Venue: SIAM Journal on Control and Optimization (1997)

We study the ergodic control problem of switching diffusions representing a typical hybrid system that arises in numerous applications such as fault-tolerant control systems, flexible manufacturing systems, etc. Under fairly general conditions, we establish the existence of a stable, nonrandomized Markov policy which almost surely minimizes the pathwise long-run average cost. We then study the corresponding Hamilton--Jacobi--Bellman (HJB) equation and establish the existence of a unique solution in a certain class. Using this, we characterize the optimal policy as a minimizing selector of the Hamiltonian associated with the HJB equations. As an example we apply the results to a failure-prone manufacturing system and obtain closed form solutions for the optimal policy.
The Determination of Implicit Polynomial Canonical Curves
Authors: William A. Wolovich, Mustafa Unel
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1998)

A new method is presented for identifying and comparing closed, bounded, free-form curves that are defined by even implicit polynomial (IP) equations in the Cartesian coordinates x and y. The method provides a new expression for an IP involving a product of conic factors with unique conic factor centers. The critical points for an IP curve also are defined. The conic factor centers and the critical points are shown to be useful related points that directly map to one another under affine transformations. In particular, the explicit determination of such points implies both a canonical form for the curves and the transformation matrix which relates affine equivalent curves.
Complete Clock-Feedthrough Cancellation in Switched-CurrentCircuits by Combining the Replica Technique and the N-step Principle
Authors: X. Zeng, C. K. Tse, P. S. Tang
Venue: Analog Integrated Circuits and Signal Processing (1997)

This paper begins with an analysis of the charge injection error in the second-generation current memory cell. By combining the circuit-replication technique and the n-step principle, a new scheme for simultaneously cancelling both signal-dependent and signal-independent charge injection errors in second-generation switched-current circuits is proposed. SPICE simulations are used to verify the feasibility and effectiveness of the proposed cell for tackling the charge injection problem. Major merits of the proposed cell include capability to meet high precision requirements and applicability to any second-generation switched-current circuit configuration.
A Wavelet-Based Multiresolution Method to AutomaticallyRegister Images
Authors: Joachim Deubler, Jean-Christophe Olivo
Venue: Journal of Mathematical Imaging and Vision (1997)

We present a method to automatically register images presenting both global and local deformations. The image registration process is performed by exploiting a multi-level/multi-image approach whereby after having wavelet-transformed the images, the subband images at different levels are used in a non-feature-based way to determine the motion vectors between the reference and the target images. The crude motion field determined by block matching at the coarsest level of the pyramid is successively refined by taking advantage of both the orientation sensitivity of the different subbands and the contribution of the adjacent levels. The final registered image is obtained by applying the motion field to the lowest level of the pyramid and by inversely transforming it.