ppxscal/embedding_network huggingface dataset:
Bolza Problems with General Time Constraints
Authors: P. D. Loewen, R. T. Rockafellar
Venue: SIAM Journal on Control and Optimization (1997)

This work provides necessary conditions for optimality in problems of optimal control expressed as instances of the generalized problem of Bolza, with the added feature that the fundamental planning interval is allowed to vary. A central product of the analysis is a generalization of the conservation-of-Hamiltonian condition for problems on either fixed or variable intervals. The results, which allow for unprecedented generality in the problem data, are derived from known properties of fixed-interval problems under the hypothesis that the time-dependence of the objective integrand has the same modest level of regularity as the state-dependence.
Algorithm visualization on the World Wide Web&mdash;the difference Java makes!
Authors: Thomas L. Naps
Venue: Proceedings of the 2nd conference on Integrating technology into computer science education (1997)

Using algorithm visualization, we can depict the execution of an algorithm as a sequence of graphical snapshots, the viewing of which is controlled by the user. Such visualizations can be a tremendous help to students, but their use is limited by the constraints of platform dependency. This constraint can now be overcome by making algorithm visualizations conveniently accessible on the World Wide Web. This paper provides an overview of progress that has been made in delivering interactive visualizations in platform-independent fashion on the Web. In particular the role played by Java in implementing one such system is explored in depth.
Avoiding Cartesian products for multiple joins
Authors: Shinichi Morishita
Venue: Journal of the ACM (JACM) (1997)

Computing the natural join of a set of relations is an important operation in relational database systems. The ordering of joins determines to a large extent the computation time of the join. Since the number of possible orderings could be very large, query optimizers first reduce the search space by using various heuristics and then try to select an optimal ordering of joins. Avoiding Cartesian products is a common heuristic for reducing the search space, but it cannot guarantee optimal ordering in its search space, because the cheapest Cartesian-product-free (CPF for short) ordering could be significantly worse than an optimal non-CPF ordering by a factor of an arbitrarily large number. In this paper, we use programs consisting of joins, semijoins, and projections for computing the join of some relations, and we introduce a novel algorithm that derives programs from CPF orderings of joins. We show that there exists a CPF ordering from which our algorithm derives a program whose cost is within a constant factor of the cost of an optimal ordering. Thus, our result demonstrates the effectiveness of avoiding Cartesian products as a heuristic for restricting the search space of orderings of joins.
Data and Model-Driven Selection Using Color Regions
Authors: Tanveer Fathima Syeda-Mahmood
Venue: International Journal of Computer Vision (1997)

A key problem in model-based object recognition is selection, namely, the problem of determining which regions in the image are likely to come from a single object. In this paper we present an approach that uses color as a cue to perform selection either based solely on image-data (data-driven), or based on the knowledge of the color description of the model (model-driven). Specifically, the paper presents a method of color specification in terms of perceptual color categories and shows its relevance for the task of selection. The color categories are used to develop a fast region segmentation algorithm that extracts perceptual color regions in images. The color regions extracted form the basis for performing data and model-driven selection. Data-driven selection is achieved by selecting salient color regions as judged by a color-saliency measure that emphasizes attributes that are also important in human color perception. The approach to model-driven selection, on the other hand, exploits the color and other region information in the 3d model object to locate instances of the object in a given image. The approach presented tolerates some of the problems of occlusion, pose and illumination changes that make a model instance in an image appear different from its original description. Finally, the utility of color-based selection is demonstrated by showing the extent of search reduction possible when color-based selection is integrated with a recognition system.
The Reconfigurable Ring of Processors: Fine-Grain Tree-Structured Computations
Authors: Arnold L. Rosenberg, Vittorio Scarano, Ramesh K. Sitaaman
Venue: IEEE Transactions on Computers (1997)

We study fine-grain computation on the Reconfigurable Ring of Processors $({\cal RRP}),$ a parallel architecture whose processing elements (PEs) are interconnected via a multiline reconfigurable bus, each of whose lines has one-packet width and can be configured, independently of other lines, to establish an arbitrary PE-to-PE connection. We present a "cooperative" message-passing protocol that will, in the presence of suitable implementation technology, endow an ${\cal RRP}$ with message latency that is logarithmic in the number of PEs a message passes over in transit. Our study focuses on the computational consequences of such latency in such an architecture. Our main results prove that: 1) an N-PE ${\cal RRP}$ can execute a sweep up or down an N-leaf complete binary tree in time proportional to log N log log N; 2) a broad range of N-PE architectures, including N-PE ${\cal RRP}{\rm s},$ require time proportional to log N log log N to perform such a sweep.
Moving Practice: From Classrooms to MOO Rooms
Authors: Vicki O‘Day, Daniel Bobrow, Kimberly Bobrow, Mark Shirley, Billie Hughes, Jim Walters
Venue: Computer Supported Cooperative Work (1998)

We discuss design considerations in moving practice through the boundary from physical to virtual places. Although the examples are grounded in a school environment, we believe that the design tradeoffs apply to any networked collaborative space. The context for discussion is Pueblo, a MOO-based, cross-generation network learning community centered around a K-6 elementary school. The development of practice in Pueblo draws upon teachers&lsquo; and students&lsquo; experience with semi-structured classroom participation frameworks &ndash; informal structures of social interaction which foster certain ways of thinking, doing, and learning through guided activities and conversations. We have translated several familiar frameworks into the Pueblo setting, using the classroom versions as models to be adapted and transformed as they are aligned with the affordances of the MOO. We identify four design dimensions that have emerged as particularly interesting and important in this process: audience, asynchrony and synchrony, attention and awareness, and prompts for reflection. We illustrate design choices in each dimension using several of the participation frameworks that have been translated into Pueblo. We discuss the relation between MOO affordances and design choices and provide examples of successful and unsuccessful alignment between them.
A system to project injury and illness incidence during military operations
Authors: Christopher G. Blood, Ed O'Donnell, Dan Rotblatt
Venue: Proceedings of the 28th conference on Winter simulation (1996)

Modeling of medical resource requirements during military operations requires projections of disease and non-battle injury (DNBI) and wounded-in-action (WIA) rates. Historical data were extracted from unit diaries of infantry and support troop deployed during four previous combat engagements. A planning tool (FORECAS) was developed that uses the statistical distributions of DNBI and WIA incidence from previous operations to simulate injury and illness arrival rates for future scenarios. Output of the simulated data reflects the nuances of the empirical data.
A Formally Verified Sorting Certifier
Authors: Jonathan D. Bright, Gregory F. Sullivan, Gerald M. Masson
Venue: IEEE Transactions on Computers (1997)

In this paper, we describe the use of the certification-trail technique as the basis of a hybrid framework for building formally verified software systems. Our technique involves formally verifying only a part of a software system; however, the technique yields a software system which still satisfies the most important correctness properties. Substantial savings in the overhead of software verification, and also in program running time, are shown to be possible in comparison to traditional methods. We apply our technique to the problem of sorting, since sorting represents one of the most basic operations in computer science, and a formally verified sorting certifier should have significant applicability. The results presented in this paper represent an enhancement of the certification-trail technique relative to the detection of incorrect computational output caused by software faults.
Recognizing Nondominated Coteries and wr-Coteries by Availability
Authors: Yu-Chen Kuo, Shing-Tsaan Huang
Venue: IEEE Transactions on Parallel and Distributed Systems (1998)

Coterie is a widely accepted concept for solving the mutual exclusion problem. Nondominated coteries are an important class of coteries which have better performance than dominated coteries. The performance of a coterie is usually measured by availability. Higher availability of a coterie exhibits greater ability to tolerate node or communication link failures. In this paper, we demonstrate a way to recognize nondominated coteries using availability. By evaluating the availability of a coterie instead of using a formal proof, the coterie can be recognized as a nondominated coterie or not. Moreover, with regard to wr-coterie, a concept for solving the replica control problem, we also present a similar result for recognizing nondominated wr-coteries. Finally, we apply our results to some well-known coteries and wr-coteries.
Discrete event simulation as a tool to determine necessary nuclear power plant operating crew size
Authors: Ron Laughery, Beth M. Plott, Thomas H. Engh, Shelly Scott-Nash
Venue: Proceedings of the 28th conference on Winter simulation (1996)

There are not always sufficient resources or time available to identify human factors issues early enough for development of detailed technical bases using empirical experimentation with human subjects. Consequently, analytical approaches are needed to augment the experimental approach for human factors regulatory decision making at the US Nuclear Regulatory Commission. One analytical approach, computer modeling of human performance, is being investigated by the NRC Office of Nuclear Regulatory Research. As an example of the types of supporting research required, we discuss two specific studies pertaining to the use of Micro Saint, a discrete event simulation package, as a means of evaluating the effects of crew size on safety in a nuclear power plant setting. Both studies provided data that permit an evaluation of the practicality and validity of using models built in Micro Saint for the specific purpose of studying staffing issues, as well as the value of modeling of human performance in general.
Synthesis of application specific programmable processors
Authors: Kyosun Kim, Ramesh Karri, Miodrag Potkonjak
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

Synthesis of Application Specific ProgrammableProcessors poses numerous new tasks onbehavioral synthesis tools.We address some ofthem including application bundling.ApplicationBundling is a synthesis task where n control-data flowgraphs are bundled into at most m groups, so that eachapplication belongs to at least one group and throughputconstraints for all applications are satisfied.We have shown how a variety of application specificconstraints such as manufacturing cost reduction andproduction risk reduction can be targeted during thesynthesis process.The effectiveness of our approach isdemonstrated on a number of real examples.
Future directions in program transformation
Authors: Alberto Pettorossi, Maurizio Proietti
Venue: ACM SIGPLAN Notices (1997)

The program transformation methodology can provide valuable techniques and tools for the development of programs from specifications and the reuse and customization of software products. Also various approaches to program optimization and program verification can be based on transformation techniques.
Vlsi Array Architectures for Pyramid Vector Quantization
Authors: Bongjin Jung, Wayne P. Burleson
Venue: Journal of VLSI Signal Processing Systems (1998)

We present parallel algorithms and array architectures for pyramid vector quantization (PVQ) [1] for use in image coding in low-power wireless systems. PVQ presents an alternative to other quantization methods which is especially suitable for symmetric peer-to-peer communications like video-conferencing. But, both the encoding and decoding algorithms have data-dependent iteration bounds and data-dependent dependencies which prevent efficient parallelization of the algorithms for either hardware or software implementations. We perform an algorithmic transformation [2] to convert the data-dependent regular algorithms to equivalent data-independent algorithms. The resulting regular algorithms exhibit modular and regular structures with minimal control overhead; hence, they are well suited for VLSI array implementation in ASIC or FPGA technologies. Based on our parallel algorithms and systematic design methodologies [3], we develop linear array architectures. Both encoder and decoder architectures consist of L identical processors with local interconnections and provide O(L) speed-up over a sequential implementation, where L is the dimension of a vector. The architectures achieve 100% processor utilization and permit power savings through early completion. A combined encoder-decoder architecture is also presented.
A Constrained Procrustes Problem
Authors: Lars-Erik Andersson, Tommy Elfving
Venue: SIAM Journal on Matrix Analysis and Applications (1997)

The following constrained matrix problem is studied. Find the matrix $X$ that minimizes the Frobenius norm of $AX-B$, with $A$ and $B$ as given matrices and where $X$ belongs to a closed convex cone. In particular we consider the cone of symmetric positive semidefinite (SPSD) matrices and the cone of (symmetric) elementwise nonnegative matrices. The optimal matrix is characterized, and the results are specialized to the two cases above. Further, we report from a numerical study of some projection-type algorithms.
Face Recognition by Elastic Bunch Graph Matching
Authors: Laurenz Wiskott, Jean-Marc Fellous, Norbert Krüger, Christopher von der Malsburg
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1997)

We present a system for recognizing human faces from single images out of a large database containing one image per person. Faces are represented by labeled graphs, based on a Gabor wavelet transform. Image graphs of new faces are extracted by an elastic graph matching process and can be compared by a simple similarity function. The system differs from the preceding one [1] in three respects. Phase information is used for accurate node positioning. Object-adapted graphs are used to handle large rotations in depth. Image graph extraction is based on a novel data structure, the bunch graph, which is constructed from a small set of sample image graphs.
Terrain database interoperability issues in training with distributed interactive simulation
Authors: Guy A. Schiavone, S. Sureshchandran, Kenneth C. Hardis
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1997)

In Distributed Interactive Simulation (DIS), each participating node is responsible for maintaining its own model of the synthetic environment. Problems may arise if significant inconsistencies are allowed to exist between these separate world views, resulting in unrealistic simulation results or negative training, and a corresponding degradation of interoperability in a DIS simulation exercise. In the DIS community, this is known as the simulator terrain database (TDB) correlation problem. This is part of the larger synthetic environment correlation problem in DIS, which includes atmosphere, ocean, space, and a wide variety of dynamic effects, behaviors and models. In this article, we investigate the terrain database correlation problem and the resultant effects on interoperability in DIS systems. The fundamental elements of terrain databases designed for real-time distributed simulation are introduced. A generic data pipeline for terrain database generation systems is developed for the purpose of illustrating causes of the correlation problem and issues of terrain database fidelity. Implications of the problem are discussed, and testing methodologies are recommended for its mitigation. Several statistical methods have been developed to analyze consistency between various elements of the synthetic environment across DIS platforms. Correlation metrics have been formulated for terrain elevations and features. Comparisons and consistency of final rendered images have been addressed. Finally, a suite of software tools that has been developed for interoperability investigations and visual comparison of terrain databases is presented.
A fine-grained MIMD architecture based upon register channels
Authors: Rajiv Gupta
Venue: Proceedings of the 23rd annual workshop and symposium on Microprogramming and microarchitecture (1990)

This paper discusses the use of shared register channels as a data exchange mechanism among processors in a fine-grained MIMD system with a load/store architecture. A register channel is provided with a synchronization bit that is used to ensure that a processor succeeds in reading a channel only after a value has been written to the channel. The instructions supported by this load/store architecture allow both registers and register channels to be used as operand sources and result destinations. Conditional load, store, and move instructions are provided to allow processors to exchange values through channels in presence of aliasing caused by array references. Compiler support required to take proper advantage of channels is briefly discussed. In contrast to a VLIW machine a system with channels does not require strict lockstep operation of its processors. This reduces the delays caused by unpredictable events such as memory bank conflicts.
Efficient Totally Self-Checking Shifter Design
Authors: Ricardo O. Duarte, M. Nicolaidis, H. Bederr, Y. Zorian
Venue: Journal of Electronic Testing: Theory and Applications (1998)

Self-checking designs will gain increasing interest in industrial applications if they satisfy the following requirements: high fault coverage, reduced hardware cost and reduced design effort. This work is aimed to reach these requirements for the design of self-checking shifters and is part of a broader project concerning the design of self-checking data paths.
Downward Separation Fails Catastrophically for Limited Nondeterminism Classes
Authors: R. Beigel, J. Goldsmith
Venue: SIAM Journal on Computing (1998)

The $\beta$ hierarchy consists of classes $\beta_k={\rm NP}[logkn]\subseteq {\rm NP}$. Unlike collapses in the polynomial hierarchy and the Boolean hierarchy, collapses in the $\beta$ hierarchy do not seem to translate up, nor does closure under complement seem to cause the hierarchy to collapse. For any consistent set of collapses and separations of levels of the hierarchy that respects ${\rm P} = \beta_1\subseteq \beta_2\subseteq \cdots \subseteq {\rm NP}$, we can construct an oracle relative to which those collapses and separations hold; at the same time we can make distinct levels of the hierarchy closed under computation or not, as we wish. To give two relatively tame examples: for any $k \geq 1$, we construct an oracle relative to which \[ {\rm P} = \beta_{k} \neq \beta_{k+1} \neq \beta_{k+2} \neq \cdots \] and another oracle relative to which \[ {\rm P} = \beta_{k} \neq \beta_{k+1} = {\rm PSPACE}. \] We also construct an oracle relative to which $\beta_{2k} = \beta_{2k+1} \neq \beta_{2k+2}$ for all k.
Easily Testable Realizations for Generalized Reed-Muller Expressions
Authors: Tsutomu Sasao
Venue: IEEE Transactions on Computers (1997)

This paper presents a design method of easily testable AND-EXOR networks. It is an improvement of Reddy and Saluja-Reddy's methods, and has the following features: 1) The network uses generalized Reed-Muller expressions (GRMs) instead of Positive Polarity Reed-Muller expressions (PPRMs). The average number of products for GRMs is less than half of that for PPRMs, and is less than that of sum-of-products expressions (SOPs). 2) The network consists of a literal part, an AND part, an EXOR part, and a check part. 3) The EXOR part can be a tree instead of a cascade. Thus, the network is faster. 4) The test detects multiple stuck at faults under the assumption that the faults occur at most one part, either the literal part, the AND part, the EXOR part, or the check part.
An Enhancement of Generalization Ability in Cascade CorrelationAlgorithm by Avoidance of Overfitting/Overtraining Problem
Authors: Igor V. Tetko, Alessandro E. P. Villa
Venue: Neural Processing Letters (1997)

The current study investigates a method for avoidance of an overfitting/overtraining problem in Artificial Neural Network (ANN) based on a combination of two algorithms: Early Stopping and Ensemble averaging (ESE). We show that ESE provides an improvement of the prediction ability of ANN trained according to Cascade Correlation Algorithm. A simple algorithm to estimate the generalization ability of the method according to the Leave-One-Out technique is proposed and discussed. In the accompanying paper the problem of optimal selection of training cases is considered for accelerated learning of the ESE method.
Trade-Off Analysis of a Low-Power Image Coding Algorithm
Authors: K. Masselos, P. Merakos, T. Stouraitis, C. E. Goutis
Venue: Journal of VLSI Signal Processing Systems (1998)

In this paper, a novel algorithm for low-power image coding and decoding is presented and the various inherent trade-offs are described and investigated in detail. The algorithm reduces the memory requirements of vector quantization, i.e., the size of memory required for the codebook and the number of memory accesses by using small codebooks. This significantly reduces the memory-related power consumption, which is an important part of the total power budget. To compensate for the loss of quality introduced by the small codebook size, simple transformations are applied on the codewords during coding. Thus, small codebooks are extended through computations and the main coding task becomes computation-based rather than memory-based. Each image block is encoded by a codeword index and a set of transformation parameters. The algorithm leads to power savings of a factor of 10 in coding and of a factor of 3 in decoding, at least in comparison to classical full-search vector quantization. In terms of SNR, the image quality is better than or comparable to that corresponding to full-search vector quantization, depending on the size of the codebook that is used. The main disadvantage of the proposed algorithm is the decrease of the compression ratio in comparison to vector quantization. The trade-off between image quality and power consumption is dominant in this algorithm and is mainly determined by the size of the codebook.
The Reed-Muller Code R(1,7) Is Normal
Authors: Xiang-Dong Hou
Venue: Designs, Codes and Cryptography (1997)

We prove that the Reed-Muller code R(1,7) is normal. The normality of R(1,7) was a long-standing open question, and has an important consequence in a conjecture about the function t[n,k], the smallest covering radius of any [n,k] binary linear code.